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Article

Bioactivity and Chemical Profile of Rubus idaeus L. Leaves Steam-Distillation Extract

by
Diana De Santis
1,*,
Katya Carbone
2,
Stefania Garzoli
3,
Valentina Laghezza Masci
1 and
Giovanni Turchetti
1
1
Department for Innovation in the Biological, Agrofood and Forestry Systems, University of Tuscia Via S. C. de Lellis, 01100 Viterbo, Italy
2
CREA Research Centre for Olive, Fruit and Citrus Crops, Via di Fioranello 52, 00134 Rome, Italy
3
Department of Drug Chemistry and Technology, Sapienza University, Square Aldo Moro 5, 00185 Rome, Italy
*
Author to whom correspondence should be addressed.
Foods 2022, 11(10), 1455; https://doi.org/10.3390/foods11101455
Submission received: 21 April 2022 / Revised: 4 May 2022 / Accepted: 12 May 2022 / Published: 17 May 2022
(This article belongs to the Section Plant Foods)

Abstract

:
The leaves of Rubus idaeus L., a by-product of the fruit food industry, are a known source of bioactive molecules, although the chemical composition has only been partially investigated. The main objective of this study was to examine the biological activities and the chemical composition of the extract of leaves of R. idaeus (RH), obtained by steam distillation (SD). The antioxidant capacity; the total phenolic content (TPC); the cytotoxic activity against tumor cell lines; and the antibacterial activity, in addition to the study of the chemical fingerprinting, carried out by Gas/Chromatography-Mass-Spectrometry (GC/MS) and Headspace (HS)-GC/MS, were established. The extract showed a strong antioxidant capacity and a modest antibacterial activity against two bacterial strains, as well as significant cytotoxic activity against tumor cell lines (Caco-2 and HL60) and being proliferative on healthy cells. Many of the GC-identified volatile molecules (1,8-cineol, β-linalool, geraniol, caryophyllene, τ-muurolol, citral, α-terpineol, 3- carene, α-terpinen-7-al, etc.) can explain most of the biological properties exhibited by the extract of R. idaeus L. The high biological activity of the RH and the high compatibility with the various matrices suggest good prospects for this extract, both in the food and cosmetic fields or in dietary supplements for improving human health.

1. Introduction

R. idaeus L., called “Raspberry” or “Red Raspberry”, is a plant that belongs to the Rosaceae family, widely cultivated in Europe, North America, and Asia. Raspberry fruits are one of the world’s most consumed berries, available as fresh, frozen, and freeze-dried commodities. Moreover, they are also used in food manufacturing for purees, juices, jams, wines, etc. According to Faostat [1], in 2020, the world production of raspberries was 895.771 tons, with a cultivated area of just over 110,000 hectares, with Europe holding the highest share of raspberry production. These fruits are commonly known as superfoods because of their very high content of natural antioxidants and vitamins [2]. Besides, their production and processing generate different byproducts, such as stems, seeds, and leaves, which can be recovered and incorporated into new food and cosmetic or pharmaceutical products [3,4,5]. In particular, the therapeutic properties of the leaves of R. idaeus L. have been known since ancient times, recommended for the treatment of various unhealthy conditions, and included in herbal preparations for relaxation of the uterus during childbirth [6,7]. In addition, raspberry leaves are used as an additive in beverages and dietary supplements and in the formulation of functional herbal teas, teas, and chocolate, improving their nutritional properties and flavor [7,8,9,10,11,12,13].
Antibiotic resistance is a health problem that causes the deaths of around 700,000 people every year, and the scientific world predicts it will rise to 10 million a year by 2050 [14]. Bacteria acquire resistance to antibacterial agents according to two possible mechanisms, vertical (by the isolated evolution of the strain) or horizontal (by the resistance genes exchanged between strains or individuals of the same species). World trade; population growth; and the massive use of antibiotics in agriculture, fisheries, and veterinary medicine raise the issue of the multi-drug resistance of microorganisms in the food chain [15,16,17]. In addition to the above, Mensah and colleagues [18] pointed out that residues of antimicrobial agents in food can lead to public health problems due to the emergence of multidrug-resistant strains, allergic reactions, hepatotoxicity, and other medical complications. The unsuccessful and irresponsible use of current antibiotics is becoming a growing problem. For this reason, the study of active plant matrices has focused on the search for molecules that can exert an antimicrobial action alone or in combination with existing antibiotics. To the best of our knowledge, detailed research of raspberry leaves distillate has not yet been undertaken.
In this regard, the volatile compounds of R. idaeus leaves were isolated by steam distillation, and the obtained distillate was subsequently analyzed by HS-GC/MS and GC/MS. To further evaluate the potential of the distillate for applications in food, medicine, and health products, its total polyphenol content, as well as antioxidant capacity and antiproliferative and antibacterial activities were assessed in vitro towards DPPH, ABTS, FRAP, human colorectal adenocarcinoma cells, human promyelocytic leukemia cells, normal breast epithelial cells, and different strains of both Gram positive and negative bacteria, respectively.

2. Materials and Methods

2.1. Reagents and Chemicals

All the chemicals used for the experiments were of analytical grade. Folin–Ciocalteau, sodium carbonate, gallic acid, reagents for the cell and bacteria cultures, and antiproliferative antibacterial assays were purchased from Merck KGaA (Darmstadt, Germany); 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-pikryl-hydrazyl (DPPH), and other antioxidant reagents were obtained from Sigma (St Louis, MO, USA). Dimethyl sulfoxide was purchased from Biochem Chemopharma (Cosne-Cours-sur-Loire, France) and gentamicin from Biochrom AG (Berlin, Germany).

2.2. Plant Material, Experimental Design, and Extraction Process

Raspberry (R. idaeus L.) leaves, cv. Heritage, used in this study were harvested in September 2020, at the “Lamponi Monti Cimini” farm, located in Viterbo (Lazio region, Italy), at about 750 m above sea level, with a moisture content of approximately 31 ± 1% (w/w). The leaves, immediately transported to V. Cardarelli Institute laboratory (Tarquinia, Viterbo, Italy) after harvesting, were weighed, washed, and steam-distilled using a 30-L extractor from Manufattinox company (Scambiatterra Francesco—Varapodio, RC, Italy). In the distillation process, about 2 kg of fresh raspberry leaves were placed inside the boiler, on a perforated grid, positioned about 3 cm above 3.5 L of boiling water, and a hydrolate (RH) was collected (200 mL) and stored at 4 °C until extraction.

2.3. Moisture

The leaf moisture value was determined on an aliquot of dried sample (about 5 g) in an oven (NF 400 Nüve Sanayi, Akyurt-Ankara) at 65 ± 2 °C until a constant weight was reached. Three replicates were performed, and the results were averaged.

2.4. Total Phenol Content Assay

Total Phenol Content (TPC) of RH samples was evaluated spectrophotometrically according to the Folin method [19]. Briefly, 20 µL of RH, diluted with 1580 µL of distilled water and 100 µL of Folin—Ciocalteu reagent (2 M), was incubated for 5 min in the dark, at room temperature. Afterwards, 300 µL of Na2CO3 (20%, w/v) was added, and the mixture was left at room temperature for 2 h. A calibration curve was generated with standard solutions of gallic acid (20–200 µg mL−1), and the measures were carried out at 760 nm using a UV-VIS spectrophotometer (Perkin Elmer model Lambda 850+). All analyses were performed in triplicate. TPC was expressed as milligrams of gallic acid equivalents per mL of sample (mg GAE mL−1).

2.5. VOCs Analysis

2.5.1. Headspace-Gas Chromatography Mass Spectrometry (HS-GC/MS)

A Perkin–Elmer Headspace Turbomatrix 40 autosampler connected to a Clarus 500 GC/MS was used for the chemical qualitative–quantitative analysis of the vapor phase of RH. A total of 2 mL of the sample was placed in a 20 mL vial sealed with headspace PTFE-coated silicone rubber septa and caps. The headspace-applied parameters followed Garzoli et al. [20], with some modifications. The GC was equipped with a Restek Stabilwax (fused-silica) polar capillary column, and helium as carrier gas (1.0 mL min−1) was used. The column temperature was programmed as follows: from 60 °C to 220 °C at a rate of 5 °C min−1 and held for 15 min. The MS parameters were ionization voltage taken at 70 eV; mass range was from 40 to 500 m/z, ion source temperature of 200 °C, and scan time of 0.2 s.
Relative percentages for quantification of the components were calculated by electronic integration of the GC/FID peak areas using the normalization method without using corrections factors (RRFs). The identification of the components separated by GC/MS was performed first by comparing the mass spectra for each compound with that reported on the MS libraries database (Wiley and Nist 02) and then by comparison of Linear retention indices (LRI) of each compound, calculated using a mixture of n-alkanes (C8-C30, Ultrasci), with those reported in the literature for an apolar column. All analyses were performed in triplicate.

2.5.2. Gas Chromatography Mass Spectrometry (GC/MS) of Hexanoic Extract

For GC/MS analysis, because no essential oil was isolated, volatile compounds were extracted from the hydrosol obtained by steam distillation. Briefly, 20 mL of RH were mixed with 1 mL of n-hexane and stirred in the dark at room temperature. Subsequently, the hexane layer was collected and stored at −20 °C until use. The gas chromatography–mass spectrometry (GC/MS) analysis was performed on an Agilent 7890A Series GC system, coupled with a 5975C mass detector (Agilent Technologies, Milan, Italy). An Agilent Ultra Inert GC column with an HP-5MS-fused silica capillary (5%-diphenyl95%-dimethyl polysiloxane, 30 m, 0.25 mm i.d., 0.25 mm film thickness) (Agilent Technologies, Palo Alto, CA) was used to provide the analyte separation, and helium was used as a carrier gas (1 mL min−1). The GC oven temperature gradient started from 50 °C and was held for 3 min; then, the temperature was raised to 200 °C (5 °C min−1). The final temperature was maintained for 18 min [21]. The injector was maintained at 250 °C, operating in the spitless modality.
The mass spectrometer was equipped with an electron impact (EI) source (70 eV), and the acquisition mode was in full scan (from 40 to 600 m/z). A solvent delay time of 4.10 min was applied. GC/MS data were acquired, and the total ion chromatograms (TIC) were integrated by using MassHunter software (version B.05.00; Agilent Technologies, Milan, Italy). Quantitative analyses of each component (expressed as area percentage) were carried out by a peak area normalization measurement, calculated as mean values of three sample injections. The linear retention index (LRI) of each compound was calculated, referring to the retention times (RT) of a C7-C25 n-alkanes standard mixture under the same conditions.
The identification of the compounds was performed by matching their recorded mass spectra with the standard mass spectra in NIST11 library and in the National Institute of Standards and Technology Gas Chromatography Library (http://webbook.nist.gov/chemistry, accessed on 16 July 2020), as well as by comparing their MS fragmentation patterns and LRIs with literature data [22,23,24] and the available online mass spectra data bank (MoNA—MassBank of North America; https://mona.fiehnlab.ucdavis.edu/, accessed on 16 July 2020).

2.6. Cell Viability Assay

2.6.1. Eukaryotic Cell Culture

Three different cell lines were used: human colorectal adenocarcinoma cells (Caco-2, ATCC® HTB-37™), human acute promyelocytic leukemia cells (HL60, ATCC CCL-240), and normal breast epithelial cells (MCF10A, ATCC® CRL-10317™). Caco-2 cells were cultured in high glucose Dulbecco’s Modified Eagle Medium (DMEM), supplemented with 10% Fetal Bovine Serum (FBS), 1% w/v glutamine, 1% w/v sodium pyruvate, 1% w/v non-essential amino acids, and 1% penicillin-streptomycin. HL60 were cultured in Roswell Park Memorial Institute (RPMI)-1640, supplemented with 10% FBS (v/v), 1% glutamine (w/v), and 1% penicillin-streptomycin (v/v). MCF10A were maintained in DMEM F-12 supplemented with 100 ng mL1 cholera toxin, 20 ng mL1 epidermal growth factor (EGF), 0.01 mg mL1 insulin, 500 ng mL1 hydrocortisone, 5% Horse Serum (HS) (v/v), 1% glutamine, and 1% penicillin-streptomycin; before being seeded for the viability assay, the culture medium was deprived of Epidermal Growth Factor (EGF) and the HS reduced to 2%. All the cell lines were maintained at 37 °C in a humidified 5% CO2 atmosphere condition. All experiments were performed with the cells in their logarithmic growth phase.

2.6.2. Cytotoxicity Assay

In vitro cytotoxic effects of RH were investigated in triplicate by the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay, according to Nguyen and colleagues [25] with minor modifications. Briefly, on 2 × 104 cells/well seeded in a 96-well microplate 24 h before treatments, 10 2-fold dilutions from 25% to 0.05% (v/v, Medium/RH) were used and incubated for 48 h. After the incubation time, the medium-containing treatment was removed, and 100 µL of MTT solution (0.5 mg mL1) was added to each well and incubated in the dark at 37 °C for 3 h. The formazan crystals were dissolved in 100 µL of DMSO, and the absorbance was measured at 570 nm. The cytotoxicity effect of RH was estimated as the percentage of viable cells relative to a control (untreated cells).

2.7. Antibacterial Assay

2.7.1. Prokaryotic Cell Culture

Five bacteria strains were used to evaluate the antibacterial effects of RH: three Gram-negative strains (Escherichia coli ATCC 25922, Acinetobacter bohemicus DSM 102855, and Pseudomonas fluorescens ATCC 13525) and two Gram-positive strains (Bacillus cereus ATCC 10876 and Kocuria marina DSM 16420). All strains were maintained in Lysogeny agar at different temperatures: 26 °C for B. cereus, P. fluorescens, and A. bohemicus and 37 °C for K. marina and E. coli. All inocula were prepared with fresh bacteria plated the day before the test.

2.7.2. Agar Diffusion Method

The antimicrobial activity of samples analyzed was investigated by the disk diffusion test, according to Hudzicki [26]. Each bacterial strain was tested at 0.5 McFarland, which is equivalent to a bacterial suspension containing between 1 × 108 and 2 × 108 CFU mL−1, in duplicate, and the halo of the inhibition zones was measured using a vernier caliper rule.

2.8. Antioxidant Activities

2.8.1. DPPH Scavenging Activity

The DPPH radical scavenging activity was determinate according to the protocol described by Blois [27], adapted for 96-well plates. A total of 100 µL of different concentrations (1000–0.49 µM) of Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) and 100 µL of RH were mixed and serially diluted (1:2) in methanol. Then, 100 µL of 0.2 mM DPPH• pure methanol solution was added to each well and kept at room temperature for 30 min in the dark. After, the absorbance was read at 517 nm in a UV spectrophotometer plate-reader (Sunrise, Tecan, Inc., San Jose, CA, USA). The results were expressed as the µM of Trolox Equivalents (TE) mL1 of RH used.

2.8.2. ABTS•+ Scavenging Activity

The antioxidant capacity was assessed by an ABTS assay as described by Bueno-Costa et al. [28], with minor modifications. Briefly, 5 mL of 7 mM ABTS in distillated water was prepared and mixed with 88 µL of 140 mM potassium persulfate (K2S2O8) and left to react for 12–16 h at room temperature under dark conditions. The ABTS•+ solution was diluted with ethanol until an absorbance of 0.7 ± 0.02 was read at 734 nm prior to use. Trolox solution was prepared and used as a standard at different concentrations (0.25–4 µM). A total of 20 µL of sample/standard were added to 980 µL of ABTS•+ solution and left to react for 5 min. After the reaction time, the absorbance was evaluated using a spectrophotometer (Perkin Elmer Lambda 25 UV/VIS spectrometer, Norwalk, CT, USA) at 734 nm. The results were expressed as µM of TE mL−1 of RH used.

2.8.3. FRAP Assay

The procedure described by Gül and Pehlivan was followed [29]. The principle of this method is based on the reduction of a ferric-tripyridyl triazine complex to its ferrous, colored form in the presence of antioxidants. The results were expressed as µM of TE mL1 of RH used.

2.9. Statistical Analysis

Data were reported as mean ± standard deviation (SD) of at least two independent experiments with three replicates. A one-way analysis of variance (ANOVA) was used to analyze the data, followed by the Least Significant Difference (LSD) test (p < 0.05) (XL-Stat-Addinsoft, 2019)

3. Results

3.1. General Aspects

In the present study, steam distillation and extraction processes were applied to fresh raspberry leaves, cv Heritage, to produce and characterize a functional distillate to be used in sectors like food, cosmetics, and phytotherapic ones. Steam distillation allows a good separation of the plant’s volatile active components, avoiding the solvent removal phase or the using of aggressive chemicals, which could create artifacts in the distillate. In the experimental conditions used, a 10% (v/w) distillate was obtained, with a pH value 4.06 ± 0.05 and a density of 0.993 ± 0.004 g cm3.
Raspberry leaves are rich in bioactive compounds, mainly hydrolysable tannins (2.6–6.9% of dried leaf mass); flavonoids, including quercetin and kaempferol-3-O-glucoside (0.46–1.05%) [30]; and smaller amounts of phenolic acids, such as chlorogenic, gallic, ferulic, and caffeic acids [31].
However, the knowledge of the composition and the positive effects on health of the bioactive substances contained in the distillate of raspberry leaves is not as widespread as the knowledge about their polyphenolic profile.
Although no reports on volatile metabolites from R. ideaus leaves have been published, other Rubus species have been phytochemically investigated for their volatile compounds. Cai et al. [32] analyzed the components contained in the hydro-distillated volatile oil from R. parvifolius L. leaves by GC/MS. They identified 29 compounds, with 4-hydroxy-3-metoxystirene being the most abundant one (66.05%), followed by 2-hexadecen-1-ol (9.79%), 4-tert-butyl benzoic acid (2.22%), hexanoic acid (2.03%), and linalool (1.39%). The authors also pointed out that the extracted oil effectively inhibited the growth of a wide range of Gram positive and negative bacteria. The importance of discovering new antibacterial agents is growing every year.

3.2. HS-GC/MS Identification of Volatile Compounds

The volatile organic compounds (VOCs) in the headspace of the RH were analyzed by HS-GC/MS analysis. Table 1 lists all the identified compounds. In the RH headspace, 62.6% of the compounds found were oxygenated monoterpenes, mainly 1,8-cineole (50.8%), α-terpineol (5.2%), terpinyl acetate (3.7%), and camphor (2.9%).
Among the monoterpene hydrocarbons, 3-carene (16.3%) was the most abundant, followed by limonene (1.0%) and β-mircene (0.1%). Monoterpenes are well-known components of essential oils of aromatic plants, are able to penetrate the bloodstream, and act as medicinal substances, beneficial for humans [33,34,35,36].
VOCs found in the RH headspace have important biological properties, as reported in the literature data. Among these, 1,8-cineole stands out in percentage terms, probably for its high solubility in water. This compound, found in several species of aromatic plants (eucalyptus, thyme, rosemary, sage, etc.), is a cyclic ether monoterpenoid naturally produced, approved by the Food and Drug Administration for food use, and, in 1965, it obtained GRAS (Generally Recognized As Safe) status by FEMA (Flavor and Extract Manufacturers Association of the United States). Its pharmacological properties have attracted the attention of the scientific world. It is an anti-inflammatory of the airways, a mucolytic agent, and a powerful antibacterial agent against numerous strains, such as Enterococcus faecalis, Streptococcus salivarius, S. sanguinis, B. subtilis, Staphylococcus aureus, E. coli, S. epidermidis, and Aspergillus niger [37], as well as in vitro and in vivo antitumor effects [38,39].
3-carene is a bicyclic monoterpene produced by the cyclization of geranyl diphosphate, with several properties, such as antimicrobial, antioxidant, anti-inflammatory, antiplasmodial, cytotoxic, and anti-tuberculosis properties [40].
Worthy of attention is the presence in the RH of α-terpineol (5.2%), an unsaturated monocyclic monoterpene alcohol, isolated from leaves, flowers, and aerial parts of plants. It is usually a mixture of isomers (α, β, γ-terpineol and terpin-4-ol), with α-terpineol as the main constituent. α-terpineol has a pleasant lilac-like odor and is a common ingredient in perfumes, cosmetics, and flavorings. It is also well known for its good antibacterial activity [34] and various important biological properties [41].
Among the active components of our RH, camphor (2.9%) was detected, which is also one of the main components of many plant species, with documented antibacterial and antimicrobial properties.
Limonene (1%) has antibacterial, antifungal, anti-inflammatory, antioxidant, and tumor-suppressive activity [42,43,44,45,46].

3.3. GC/MS Identification of Hexanoic Extract Compounds

The distillate collected after the steam distillation was extracted with hexane to recover the volatile compounds dissolved in the hydrosol. The GC/MS analysis of the extract revealed the presence of 80 phytochemical compounds (Figure 1), some of them not detected through HS-GC/MS analysis. The RH was rich mainly in aldehydes, ketones, alcohols, and terpenoids.
The main compounds (>1% of the total peak area) identified, characterizing the sample composition, are reported in Table 2. The major constituents of the volatile hexanoic fraction of the hydrolate were 2-hexenal (8.79%); 2-nonanone (6.88%), followed by some monoterpenoids; and 2,4-heptadienal (3.13%), among the known compounds.
Both α and β-unsaturated aldehydes and long chain methyl ketones are known to exert antimicrobial and antifungal activity [47,48,49,50,51,52,53]. The main terpenoids detected were β-linalool (6.15%), geraniol (4.45%), 1,8-cineole (2.47%), τ-muurolol (1.09%), and α-citral (1.00%) and the sesquiterpene β-caryophyllene (2.61%).
Furthermore, several literature studies have underlined the biological activity of linalool, such as anti-inflammatory and antibacterial activity [54,55]. In addition, the hexane extract confirmed the presence of 1,8-cineole (2.47%), albeit at a much lower level than found in the headspace analysis.
The monoterpenoid α-terpinen-7-al was identified (1.19%), previously reported as a safe aroma compound [56]. Among the minor components (<1%), the following were identified: camphor (0.95%) and α-terpineol (0.92%), both also found in the HS-GC/MS analysis of the hydrolate.
Regarding methyl salicylate (1.94%), it is known for its antioxidant, antimicrobial, insecticidal, and acaricidal activities [57,58,59,60]. Furthermore, the analysis revealed the presence of two acids, lauric acid (dodecanoic acid: 1.37%) and capric acid (n-decanoic acid: 1.15%), both studied for their antifungal and antibacterial activity [61,62,63].

3.4. Biological Activities of Raspberry Leaf Distillate

3.4.1. Cell Viability

Cancer therapies require continuous research to find alternative molecules for anti-tumor treatment. Over time, numerous phenomena of resistance to chemotherapy drugs have been highlighted by the scientific community, as reported by several studies, and it is thought to be the cause of mortality in more than 90% of patients with advanced cancer [64]. We wanted to test whether Rubus leaf hydrolate could have an anti-proliferative effect on cell cultures in vitro.
In the present study, the effects of the RH supplementation of the culture media were tested on two tumor cell lines, HL60 and Caco2, and on a healthy one, MCF10A. As reported in Figure 2, it is possible to notice how HL60, promyeoloblasts isolated from the peripheral blood by leukopheresis from a 36-year-old caucasian female with acute promyelocytic leukemia, and Caco2, epithelial cells isolated from colon tissue derived from a 72-year-old white male with colorectal adenocarcinoma, decreased in viability when treated with RH. Both HL60 and Caco2 cell lines showed a significant reduction (p < 0.05) in viability when treated with a 25% hydrolate solution. In particular, the residual viability of the two cell lines, HL60 and Caco2, were, respectively, 1.15% and 0.02%.
This result could be related to the presence, in the extract, of molecules such as terpenes with antitumor activity, including 1,8-cineole [65], limonene [42], α-terpineol [66], β-linalool [67], geraniol [68], caryophyllene [69], and τ-muurolol [70].
The trend observed regarding MCF10A, an epithelial cell line isolated in 1984 from the mammary gland of a 36-year-old white woman with fibrocystic breasts and used by researchers as a healthy cell model [71,72], was opposite to that related to tumor lines.
The cells showed an increase in viability when the medium was enriched with a solution of RH already at the concentration of 0.098%. When treated with 25% RH, these cells achieved a viability increase of up to 124.83%.
The antiproliferative activity of the active components of RH, identified by GC analyses, was exerted according to different mechanisms, as shown in the scientific literature.
The apoptosis is the most frequent action mechanism, common to 1,8-cineole, β-linalool, geraniol, caryophyllene, τ-muurolol, citral, α-terpineol, and 3-carene [38,73,74,75,76]. For the 1,8-cineole, specifically, the mechanism of action, partially clarified by Murata and colleagues [39], involves the activation of the caspase-3-dependent apoptosis pathway.
Other authors [65] have studied the mechanisms of action of 1,8-cineole, which confirmed cell cycle arrest in HepG2 hepatocellular carcinoma cells.
Furthermore, the antitumor activity could be related to the co-presence of 3-carene, observed by Yang and colleagues [77], on human lung cancer A549 cells. The anti-cancer activity was also demonstrated for α-terpineol, and the mechanism of action was partially elucidated by suppression of the NF-κB signal [41,78].

3.4.2. Antibacterial Activity

Several bacterial strains were tested, known to be food contaminants (E. coli, P. fluorescens, and B. cereus) and of public health concern (K. marina and A. bohemicus). Regarding the latter, K. marina is a pathogen-emerging bacterium [79,80] which can contribute to the formation of biofilms in different stages of the food chain, increasing the chances that more pathogenic bacteria, such as Listeria monocytogenes, can survive the sanitation processes or carry out cross-contamination [81]. A. Bohemicus, which belongs to the genus Acinetobacter, is instead widely studied for its strong ability to generate multi-pharmacological resistance and the horizontal transmission of resistance-associated genes [82]. As reported by several authors, this bacterium can grow in the environment (soil and water), and its presence in the food chain can occur [83,84].
The antibacterial activity of the RH samples is reported in Table 3, and it is also presented in comparison with the reference drug gentamicin. The results showed a weak intrinsic antibacterial activity compared to the reference drug only against two bacterial strains: the B. cereus strain, for which an inhibition halo of 7.67 mm was recorded, and a slightly higher effect on A. bohemicus, for which an inhibition halo of 12 mm was recorded. No inhibitory effect on growth for the other bacterial strains (E. coli, K. marina, and P. fluorescens) was found. Growth inhibition by RH samples in the two susceptible strains was one-third of that exerted by the antibiotic gentamicin. These results, considering the dilution and the aqueous nature of the tested distillate, suggest that an appropriate concentration of extract could result in similar activity, reducing the risk of induced resistance, resulting in interest for a wide range of applications.
As some authors hypothesize, the antimicrobial activity of Rubus leaves extracts could probably be related to the presence of the phenolic components, particularly ellagic acid [85]. However, a reasonable explanation for the observed antibacterial activity could also be related to monoterpenes, such as 1,8-cineole, α-terpineol, limonene, and β-myrcene [36], identified in RH samples.

3.4.3. TPC and Antioxidant Activity

To explore the intrinsic antioxidant capacity of raspberry leaf distillate, samples were tested for their ability to inhibit synthetic radicals in vitro. Results are reported in Table 4.
The value obtained in the DPPH assay was 6746 ± 555 µM TE 100 mL−1 of RH used, which is not very different from the values found in the literature [5,86,87,88,89]. Regarding the ABTS assay, the value obtained was 13.57 ± 0.56 µM TE 100 mL−1 of RH, which is slightly lower but still in line with that observed by other researchers [5,86,87,88,89,90,91,92,93,94]. In the FRAP assay, the value obtained was 307.48 ± 3.08 µM TE 100 mL−1 of RH. In this case, comparing the values with those found in the bibliography showed that the effects of the hydrolate in this assay were, in general, greater than other work [88,92,93,94,95,96,97,98,99,100]. The content of total phenols in the hydrolate was very scarce (6.25 ± 0.54 mg GAE 100 mL−1), consistent with the extraction technique adopted, and much lower than the extracts with the solvent [99,100,101,102,103,104,105].
The values of the antioxidant activity of Rubus, reported in many scientific works, show wide fluctuations. To compare the amounts found with other studies conducted on Rubus cultivars, we collected a large amount of information in Table S1, reported in the supplemental material section. As is evident, even the values obtained with the same analytical method were affected by high variability as a function of numerous factors, such as the part of the plant used (fruit, leaf, seed), the extraction system (maceration, infusion, distillation, etc.), and the solvent used, as well as the cultivation system and the environment and agrometeorological condition. All of this is consistent with the natural variability in the biosynthesis of secondary metabolites as a plant response to external stimuli.
The low quantity of phenols in the Rubus hydrolate leads to the presumption that the antioxidant activity recorded depends on other non-phenolic components, such as 1,8-cineole, β-linalool, geraniol, caryophyllene, τ-muurolol, and limonene [106,107,108,109,110].

4. Conclusions

The integrated approach conducted in this study revealed some interesting biological properties of the raspberry leaves extract, obtained by steam distillation, without organic solvents and the related problems. The volatile fraction identified with HS-GC/MS was particularly rich in terpenoids, such as 1,8-cineole (50.8%), 3-carene (16.3%), 2-heptanol (10.3%), α-terpineol (5.2%), terpinyl acetate (3.7%), pentanal (2.9%), camphor (2.9%), 1-butanol, 2-methyl- (1.6%), 3-hexen-1-ol (1.5%), and limonene (1%), molecules known for their biological properties, and other minor components, which, by synergistic effect, could enhance their activity, providing a possible explanation for the multiple functional properties. On the other hand, the GC/MS analysis of the hexane extract of Rubus leaf hydrolate revealed other compounds, such as 2-hexenal (8.79%), 2-nonanone (6.88%), β-linalool (6.15%), geraniol (4.45%), 2,4 heptadienal (3.13%), caryophyllene (2.61%), 1,8-cineole (2.47%), methyl salicylate (1.94%), 2-hexanol-3-methyl (1.59%), 4-heptanol-3-ethyl (1.56%), 2-heptanone (1.49%), dodecanoic acid (1.37%), 3-hexanol-5-methyl (1.26%), n-decanoic (1.15%), α-terpinen-7-al (1.19%), τ-muurolol (1.09%), and citral (1.00%).
The biological action exerted by the R. idaeus leaf hydrolate was observed on B. cereus and A. bohemicus strains, with an inhibition halo of 7.67 ± 1 mm and 12 ± 3 mm, respectively.
In addition, selective cytotoxicity towards cancer cells (HL60 and Caco-2) was recorded, highlighting how dose-dependent this activity is. In contrast, the healthy cells tested (MCF10A) showed increased proliferation when treated with RH.
Therefore, the study demonstrates that thanks to the chemical composition, raspberry leaves are a by-product that could have an optimal use in the food, cosmetic and pharmacological industries, both to improve the preservation and stability capacities and the functional properties of potential derivatives.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/foods11101455/s1, Table S1. Bibliographic overview of R. idaeus extracts antioxidant activity [111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135].

Author Contributions

D.D.S.: Conceptualization, Writing—original draft preparation, Methodology, Investigation, Supervision, Writing—review & editing. G.T.: Conceptualization, Writing—original draft preparation, Methodology, Investigation, Formal analysis, Writing—review & editing. K.C.: Investigation, GC/MS data curation, Writing. S.G.: Investigation, HS-GC/MS data curation, Writing. V.L.M.: Investigation, Citotoxicity data curation, Writing. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data is contained within the article or Supplementary Material.

Acknowledgments

The authors are thankful to Antonio Tiezzi for scientific contribution; Rossi Alice for support in the extraction phase; and Biaggioli Massimiliano, Lamponi dei Monti Cimini farm, for support in the provide Rubus leaves.

Conflicts of Interest

The authors declare that there is no conflict of interest.

References

  1. FAO Crops and Livestock Products—Raspberries Production. License: CC BY-NC-SA 3.0 IGO. Available online: https://www.fao.org/faostat/en/#data/QCL (accessed on 14 April 2022).
  2. Rao, A.V.; Snyder, D.M. Raspberries and human health: A review. J. Agric. Food Chem. 2010, 58, 3871–3883. [Google Scholar] [CrossRef] [PubMed]
  3. Ispiryan, A.; Viškelis, J. Valorisation of raspberries by-products for food and pharmaceutical industries. Adv. Agric. Harti. Ento. AAHE-102 2019. [Google Scholar]
  4. Marić, B.; Pavlić, B.; Čolović, D.; Abramović, B.; Zeković, Z.; Bodroža-Solarov, M.; Ilić, N.; Teslić, N. Recovery of high-content ω–3 fatty acid oil from raspberry (Rubus idaeus L.) seeds: Chemical composition and functional quality. LWT 2020, 130, 109627. [Google Scholar] [CrossRef]
  5. Wang, L.; Lin, X.; Zhang, J.; Zhang, W.; Hu, X.; Li, W.; Li, C.; Liu, S. Extraction methods for the releasing of bound phenolics from Rubus idaeus L. leaves and seeds. Ind. Crops Prod. 2019, 135, 1–9. [Google Scholar] [CrossRef]
  6. Četojević-Simin, D.D.; Velićanski, A.S.; Cvetković, D.D.; Markov, S.L.; Ćetković, G.S.; Tumbas Šaponjac, V.T.; Vulić, J.J.; Čanadanović-Brunet, J.M.; Djilas, S.M. Bioactivity of Meeker and Willamette raspberry (Rubus idaeus L.) pomace extracts. Food Chem. 2015, 166, 407–413. [Google Scholar] [CrossRef] [PubMed]
  7. Chwil, M.; Kostryco, M. Bioactive compounds and antioxidant activity of Rubus idaeus L. Leaves. Acta Sci. Pol. Hortorum Cultus 2018, 17, 135–147. [Google Scholar] [CrossRef]
  8. Veljković, B.; Dordević, N.; Dolićanin, Z.; Ličina, B.; Topuzović, M.; Stanković, M.; Zlatić, N.; Dajić-Stevanović, Z. Antioxidant and anticancer properties of leaf and fruit extracts of the wild raspberry (Rubus idaeus L.). Not. Bot. Horti Agrobot. 2019, 47, 359–367. [Google Scholar] [CrossRef] [Green Version]
  9. Belščak-Cvitanović, A.; Komes, D.; Benković, M.; Karlović, S.; Hečimović, I.; Ježek, D.; Bauman, I. Innovative formulations of chocolates enriched with plant polyphenols from Rubus idaeus L. leaves and characterization of their physical, bioactive and sensory properties. Food Res. Int. 2012, 48, 820–830. [Google Scholar] [CrossRef]
  10. Costea, T.; Vlase, L.; Gostin, I.N.; Olah, N.K.; Predan, G.M.I. Botanical characterization, phytochemical analysis and antioxidant activity of indigenous red raspberry (Rubus Idaeus L.) leaves. Stud. Univ. Vasile Goldis Arad Ser. Stiint. Vietii 2016, 26, 463–472. [Google Scholar]
  11. Durgo, K.; Belščak-Cvitanović, A.; Stančić, A.; Franekić, J.; Komes, D. The bioactive potential of red raspberry (Rubus idaeus L.) leaves in exhibiting cytotoxic and cytoprotective activity on human laryngeal carcinoma and colon adenocarcinoma. J. Med. Food 2012, 15, 258–268. [Google Scholar] [CrossRef]
  12. Ferlemi, A.V.; Lamari, F.N. Berry leaves: An alternative source of bioactive natural products of nutritional and medicinal value. Antioxidants 2016, 5, 17. [Google Scholar] [CrossRef] [PubMed]
  13. Ponder, A.; Hallmann, E. Phenolics and carotenoid contents in the leaves of different organic and conventional raspberry (Rubus idaeus l.) cultivars and their in vitro activity. Antioxidants 2019, 8, 458. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  14. McCullough, A.R.; Parekh, S.; Rathbone, J.; Del Mar, C.B.; Hoffmann, T.C. A systematic review of the public’s knowledge and beliefs about antibiotic resistance. J. Antimicrob. Chemother. 2016, 71, 27–33. [Google Scholar] [CrossRef] [PubMed]
  15. Holmes, A.H.; Moore, L.S.P.; Sundsfjord, A.; Steinbakk, M.; Regmi, S.; Karkey, A.; Guerin, P.J.; Piddock, L.J.V. Understanding the mechanisms and drivers of antimicrobial resistance. Lancet 2016, 387, 176–187. [Google Scholar] [CrossRef]
  16. Hashempour-Baltork, F.; Hosseini, H.; Shojaee-Aliabadi, S.; Torbati, M.; Alizadeh, A.M.; Alizadeh, M. Drug resistance and the prevention strategies in food borne bacteria: An update review. Adv. Pharm. Bull. 2019, 9, 335–347. [Google Scholar] [CrossRef] [Green Version]
  17. Acar, J.F.; Moulin, G. Antimicrobial resistance at farm level Resistant bacterial clones on the farm. Rev. Sci. Tech. Off. Int. Epiz. 2006, 25, 775–792. [Google Scholar] [CrossRef]
  18. Mensah, S.E.P.; Koudandé, O.D.; Sanders, P.; Laurentie, M.; Mensah, G.A.; Abiola, F.A. Antimicrobial residues in foods of animal origin in Africa: Public health risks. Rev. Sci. Tech. 2014, 33, 987–996. [Google Scholar]
  19. Waterhouse, A.L. Determination of total phenolics. Curr. Protoc. Food Anal. Chem. 2002, 6, I1.1.1–I1.1.8. [Google Scholar]
  20. Garzoli, S.; Laghezza Masci, V.; Franceschi, S.; Tiezzi, A.; Giacomello, P.; Ovidi, E. Headspace/GC–MS analysis and investigation of antibacterial, antioxidant and cytotoxic activity of essential oils and hydrolates from Rosmarinus officinalis L. and Lavandula angustifolia miller. Foods 2021, 10, 1768. [Google Scholar] [CrossRef]
  21. Rodolfi, M.; Chiancone, B.; Liberatore, C.M.; Fabbri, A.; Cirlini, M.; Ganino, T. Changes in chemical profile of Cascade hop cones according to the growing area. J. Sci. Food Agric. 2019, 99, 6011–6019. [Google Scholar] [CrossRef]
  22. Robertson, G.W.; Griffiths, D.W.; Woodford, J.A.T.; Birch, A.N.E. Changes in the chemical composition of volatiles released by the flowers and fruits of the red raspberry (Rubus idaeus) cultivar glen prosen. Phytochemistry 1995, 38, 1175–1179. [Google Scholar] [CrossRef]
  23. Adams, R.P. Identification of Essential Oil Components by Gas Chromatography/Mass Spectroscopy, 4th ed.; Allured Publishing Corporation: Carol Stream, IL, USA, 2007; Volume 456, pp. 544–545. [Google Scholar]
  24. Yang, Y.N.; Zheng, F.P.; Yu, A.N.; Sun, B.G. Changes of the free and bound volatile compounds in Rubus corchorifolius L. f. fruit during ripening. Food Chem. 2019, 287, 232–240. [Google Scholar] [CrossRef] [PubMed]
  25. Nguyen, P.A.H.; Clark, E.R.; Ananthakrishnan, S.; Lenz, K.; Canavan, H.E. How to select the appropriate method (s) of cytotoxicity analysis of mammalian cells at biointerfaces: A tutorial. Biointerphases 2020, 15, 031201. [Google Scholar] [CrossRef] [PubMed]
  26. Hudzicki, J. Kirby-Bauer disk diffusion susceptibility test protocol author information. Am. Soc. Microbiol. 2009, 15, 1–13. [Google Scholar]
  27. Blois, M.S. Antioxidant determinations by the use of a stable free radical. Nature 1958, 181, 1199–1200. [Google Scholar] [CrossRef]
  28. Bueno-Costa, F.M.; Zambiazi, R.C.; Bohmer, B.W.; Chaves, F.C.; da Silva, W.P.; Zanusso, J.T.; Dutra, I. Antibacterial and antioxidant activity of honeys from the state of Rio Grande do Sul, Brazil. LWT Food Sci. Technol. 2016, 65, 333–340. [Google Scholar] [CrossRef] [Green Version]
  29. Gül, A.; Pehlivan, T. Antioxidant activities of some monofloral honey types produced across Turkey. Saudi J. Biol. Sci. 2018, 25, 1056–1065. [Google Scholar] [CrossRef]
  30. Kratchanova, M.; Denev, P.; Ciz, M.; Lojek, A.; Mihailov, A. Evaluation of antioxidant activity of medicinal plants containing polyphenol compounds. Comparison of two extraction systems. Acta Biochim. Pol. 2010, 57, 229–234. [Google Scholar] [CrossRef] [Green Version]
  31. Pavlović, A.V.; Papetti, A.; Zagorac, D.Č.D.; Gašić, U.M.; Mišić, D.M.; Tešić, Ž.L.; Natić, M.M. Phenolics composition of leaf extracts of raspberry and blackberry cultivars grown in Serbia. Ind. Crops Prod. 2016, 87, 304–314. [Google Scholar] [CrossRef]
  32. Cai, Y.; Hu, X.; Huang, M.; Sun, F.; Yang, B.; He, J.; Wang, X.; Xia, P.; Chen, J. Characterization of the antibacterial activity and the chemical components of the volatile oil of the leaves of Rubus parvifolius L. Molecules 2012, 17, 7758–7768. [Google Scholar] [CrossRef] [Green Version]
  33. Li, Z.H.; Guo, H.; Xu, W.B.; Ge, J.; Li, X.; Alimu, M.; He, D.J. Rapid identification of flavonoid constituents directly from PTP1B Inhibitive extract of raspberry (Rubus idaeus L.) leaves by HPLC-ESI-QTOF-MS-MS. J. Chromatogr. Sci. 2016, 54, 805–810. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  34. Saad, N.; Louvet, F.; Tarrade, S.; Meudec, E.; Grenier, K.; Landolt, C.; Ouk, T.S.; Bressollier, P. Enzyme-assisted extraction of bioactive compounds from raspberry (Rubus idaeus L.) pomace. J. Food Sci. 2019, 84, 1371–1381. [Google Scholar] [CrossRef] [PubMed]
  35. Yang, J.; Cui, J.; Chen, J.; Yao, J.; Hao, Y.; Fan, Y.; Liu, Y. Evaluation of physicochemical properties in three raspberries (Rubus idaeus) at five ripening stages in northern China. Sci. Hortic. 2020, 263, 109146. [Google Scholar] [CrossRef]
  36. Koziol, A.; Stryjewska, A.; Librowski, T.; Salat, K.; Gawel, M.; Moniczewski, A.; Lochynski, S. An overview of the pharmacological properties and potential applications of natural monoterpenes. Mini Rev. Med. Chem. 2014, 14, 1156–1168. [Google Scholar] [CrossRef]
  37. De Sousa, J.P.; De Azerêdo, G.A.; De Araújo Torres, R.; Da Silva Vasconcelos, M.A.; Da Conceição, M.L.; De Souza, E.L. Synergies of carvacrol and 1,8-cineole to inhibit bacteria associated with minimally processed vegetables. Int. J. Food Microbiol. 2012, 154, 145–151. [Google Scholar] [CrossRef]
  38. Moteki, H.; Hibasami, H.; Yamada, Y.; Katsuzaki, H.; Imai, K.; Komiya, T. Specific induction of apoptosis by 1,8-cineole in two human leukemia cell lines, butnot a in human stomach cancer cell line. Oncol. Rep. 2002, 9, 757–760. [Google Scholar]
  39. Murata, S.; Shiragami, R.; Kosugi, C.; Tezuka, T.; Yamazaki, M.; Hirano, A.; Yoshimura, Y.; Suzuki, M.; Shuto, K.; Ohkohchi, N.; et al. Antitumor effect of 1, 8-cineole against colon cancer. Oncol. Rep. 2013, 30, 2647–2652. [Google Scholar] [CrossRef] [Green Version]
  40. Kamatou, G.P.P.; Makunga, N.P.; Ramogola, W.P.N.; Viljoen, A.M. South African Salvia species: A review of biological activities and phytochemistry. J. Ethnopharmacol. 2008, 119, 664–672. [Google Scholar] [CrossRef]
  41. Khaleel, C.; Tabanca, N.; Buchbauer, G. α-Terpineol, a natural monoterpene: A review of its biological properties. Open Chem. 2018, 16, 349–361. [Google Scholar] [CrossRef]
  42. De Araújo-Filho, H.G.; dos Santos, J.F.; Carvalho, M.T.B.; Picot, L.; Fruitier-Arnaudin, I.; Groult, H.; Quintans-Júnior, L.J.; Quintans, J.S.S. Anticancer activity of limonene: A systematic review of target signaling pathways. Phytoher. Res. 2021, 35, 4957–4970. [Google Scholar] [CrossRef]
  43. Cai, R.; Hu, M.; Zhang, Y.; Niu, C.; Yue, T.; Yuan, Y.; Wang, Z. Antifungal activity and mechanism of citral, limonene and eugenol against Zygosaccharomyces rouxii. LWT 2019, 106, 50–56. [Google Scholar] [CrossRef]
  44. Kummer, R.; Fachini-Queiroz, F.C.; Estevão-Silva, C.F.; Grespan, R.; Silva, E.L.; Bersani-Amado, C.A.; Cuman, R.K.N. Evaluation of anti-inflammatory activity of citrus latifolia Tanaka essential oil and limonene in experimental mouse models. Evid.-Based Complement. Altern. Med. 2013, 2013, 859083. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  45. Roberto, D.; Micucci, P.; Sebastian, T.; Graciela, F.; Anesini, C. Antioxidant activity of limonene on normal murine lymphocytes: Relation to H2O2 modulation and cell proliferation. Basic Clin. Pharmacol. Toxicol. 2009, 106, 38–44. [Google Scholar] [CrossRef] [PubMed]
  46. Zhu, Q.; Jiang, M.L.; Shao, F.; Ma, G.Q.; Shi, Q.; Liu, R.H. Chemical composition and antimicrobial activity of the essential oil from Euphorbia helioscopia L. Nat. Prod. Commun. 2020, 15, 549–555. [Google Scholar] [CrossRef]
  47. Attia, E.Z.; Abd El-Baky, R.M.; Desoukey, S.Y.; El Hakeem Mohamed, M.A.; Bishr, M.M.; Kamel, M.S. Chemical composition and antimicrobial activities of essential oils of Ruta graveolens plants treated with salicylic acid under drought stress conditions. Futur. J. Pharm. Sci. 2018, 4, 254–264. [Google Scholar] [CrossRef]
  48. Popova, A.A.; Koksharova, O.A.; Lipasova, V.A.; Zaitseva, J.V.; Katkova-Zhukotskaya, O.A.; Eremina, S.I.; Mironov, A.S.; Chernin, L.S.; Khmel, I.A. Inhibitory and toxic effects of volatiles emitted by strains of Pseudomonas and Serratia on growth and survival of selected microorganisms, Caenorhabditis elegans, and Drosophila melanogaster. Biomed Res. Int. 2014, 11, 125704. [Google Scholar]
  49. Trombetta, D.; Saija, A.; Bisignano, G.; Arena, S.; Caruso, S.; Mazzanti, G.; Uccella, N.; Castelli, F. Study on the mechanisms of the antibacterial action of some plant α,β-unsaturated aldehydes. Lett. Appl. Microbiol. 2002, 35, 285–290. [Google Scholar] [CrossRef] [Green Version]
  50. Kamdem, S.S.; Belletti, N.; Magnani, R.; Lanciotti, R.; Gardini, F. Effects of carvacrol, (E)-2-hexenal, and citral on the thermal death kinetics of listeria monocytogenes. J. Food Prot. 2011, 74, 2070–2078. [Google Scholar] [CrossRef]
  51. Ma, W.; Zhao, L.; Zhao, W.; Xie, Y. (E)-2-Hexenal, as a potential natural antifungal compound, inhibits Aspergillus flavus spore germination by disrupting mitochondrial energy metabolism. J. Agric. Food Chem. 2019, 67, 1138–1145. [Google Scholar] [CrossRef]
  52. Ma, W.; Johnson, E.T. Natural flavour (E,E)-2,4-heptadienal as a potential fumigant for control of Aspergillus flavus in stored peanut seeds: Finding new antifungal agents based on preservative sorbic acid. Food Control 2021, 124, 107938. [Google Scholar] [CrossRef]
  53. Sartori, D.; Gaion, A. Toxicity of polyunsaturated aldehydes of diatoms to Indo-Pacific bioindicator organism Echinometra mathaei. Drug Chem. Toxicol. 2016, 39, 124–128. [Google Scholar] [PubMed]
  54. Adaszyńska, M.; Swarcewicz, M.; Dziȩciol, M.; Dobrowolska, A. Comparison of chemical composition and antibacterial activity of lavender varieties from Poland. Nat. Prod. Res. 2013, 27, 1497–1501. [Google Scholar] [CrossRef] [PubMed]
  55. Aprotosoaie, A.C.; Hǎncianu, M.; Costache, I.I.; Miron, A. Linalool: A review on a key odorant molecule with valuable biological properties. Flavour Fragr. J. 2014, 29, 193–219. [Google Scholar] [CrossRef]
  56. Smith, R.L.; Waddell, W.J.; Cohen, S.M.; Feron, V.J.; Marnett, L.J.; Portoghese, P.S.; Rietjens, I.M.C.M.; Adams, T.B.; Gavin, C.L.; Mcgowen, M.M.; et al. GRAS flavoring substances 24. Food Technol. 2009, 63, 88. [Google Scholar]
  57. Gadino, A.N.; Walton, V.M.; Lee, J.C. Evaluation of methyl salicylate lures on populations of Typhlodromus pyri (Acari: Phytoseiidae) and other natural enemies in western Oregon vineyards. Biol. Control 2012, 63, 48–55. [Google Scholar] [CrossRef]
  58. Kujur, A.; Yadav, A.; Kumar, A.; Singh, P.P.; Prakash, B. Nanoencapsulated methyl salicylate as a biorational alternative of synthetic antifungal and aflatoxin B1 suppressive agents. Environ. Sci. Pollut. Res. 2019, 26, 18440–18450. [Google Scholar] [CrossRef]
  59. Lu, X.P.; Liu, J.H.; Weng, H.; Ma, Z.Q.; Zhang, X. Efficacy of binary combinations between methyl salicylate and carvacrol against thrips Anaphothrips obscurus: Laboratory and field trials. Pest Manag. Sci. 2020, 76, 589–596. [Google Scholar] [CrossRef]
  60. Oloyede, G.K. Toxicity, antimicrobial and antioxidant activities of methyl salicylate dominated essential oils of Laportea aestuans (Gaud). Arab. J. Chem. 2016, 9, S840–S845. [Google Scholar] [CrossRef] [Green Version]
  61. Anzaku, A.A.; Akyala, J.I.; Juliet, A.; Obianuju, E.C. Antibacterial activity of lauric acid on some selected clinical isolates. Ann. Clin. Lab. Res. 2017, 5, 2. [Google Scholar] [CrossRef] [Green Version]
  62. Sado Kamdem, S.; Guerzoni, M.E.; Baranyi, J.; Pin, C. Effect of capric, lauric and α-linolenic acids on the division time distributions of single cells of Staphylococcus aureus. Int. J. Food Microbiol. 2008, 128, 122–128. [Google Scholar] [CrossRef]
  63. Shen, X.; Chen, W.; Zheng, Y.; Lei, X.; Tang, M.; Wang, H.; Song, F. Chemical composition, antibacterial and antioxidant activities of hydrosols from different parts of Areca catechu L. and Cocos nucifera L. Ind. Crops Prod. 2017, 96, 110–119. [Google Scholar] [CrossRef]
  64. Catalano, A.; Iacopetta, D.; Ceramella, J.; Scumaci, D.; Giuzio, F.; Saturnino, C.; Aquaro, S.; Rosano, C.; Sinicropi, M.S. Multidrug Resistance (MDR): A widespread phenomenon in pharmacological therapies. Molecules 2022, 27, 616. [Google Scholar] [CrossRef] [PubMed]
  65. Rodenak-Kladniew, B.; Castro, A.; Stärkel, P.; Galle, M.; Crespo, R. 1,8-Cineole promotes G0/G1 cell cycle arrest and oxidative stress-induced senescence in HepG2 cells and sensitizes cells to anti-senescence drugs. Life Sci. 2020, 243, 117271. [Google Scholar] [CrossRef] [PubMed]
  66. Sales, A.; de Felipe, L.O.; Bicas, J.L. Production, properties, and applications of α-terpineol. Food Bioprocess Technol. 2020, 13, 1261–1279. [Google Scholar] [CrossRef]
  67. Rodenak-Kladniew, B.; Castro, A.; Stärkel, P.; De Saeger, C.; García de Bravo, M.; Crespo, R. Linalool induces cell cycle arrest and apoptosis in HepG2 cells through oxidative stress generation and modulation of Ras/MAPK and Akt/mTOR pathways. Life Sci. 2018, 199, 48–59. [Google Scholar] [CrossRef] [Green Version]
  68. Maczka, W.; Winska, K.; Grabarczyk, M. One hundred faces of geraniol. Molecules 2020, 25, 3303. [Google Scholar] [CrossRef]
  69. Gu, X.; Yao, X.; Mei, J.; He, H.; Gao, X.; Du, Y.; Zhao, J.; Zhao, L.; Lai, X.; Shi, K. β-caryophyllene, a natural bicyclic sesquiterpene, induces apoptosis by inhibiting inflammation-associated proliferation in MOLT-4 leukemia cells. Pharmacogn. Mag. 2021, 17, 58. [Google Scholar]
  70. Su, Y.C.; Hsu, K.P.; Wang, E.I.C.; Ho, C.L. Composition, in vitro cytotoxic, and antimicrobial activities of the flower essential oil of Diospyros discolor from Taiwan. Nat. Prod. Commun. 2015, 10, 1311–1314. [Google Scholar] [CrossRef] [Green Version]
  71. Wang, P.; Zhou, R.; Zhou, R.; Li, W.; Weerasinghe, J.; Chen, S.; Rehm, B.H.A.; Zhao, L.; Frentiu, F.D.; Zhang, Z.; et al. Cold atmospheric plasma for preventing infection of viruses that use ACE2 for entry. Theranostics 2022, 12, 2811–2832. [Google Scholar] [CrossRef]
  72. Zaręba, N.; Więcławik, K.; Kizek, R.; Hosnedlova, B.; Kepinska, M. The impact of fullerenes as doxorubicin nano-transporters on metallothionein and superoxide dismutase status in MCF-10A cells. Pharmaceutics 2022, 14, 102. [Google Scholar] [CrossRef]
  73. Abdalla, A.N.; Shaheen, U.; Abdallah, Q.M.A.; Flamini, G.; Bkhaitan, M.M.; Abdelhady, M.I.S.; Ascrizzi, R.; Bader, A. Proapoptotic activity of Achillea membranacea essential oil and its major constituent 1,8-cineole against A2780 ovarian cancer cells. Molecules 2020, 25, 1582. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  74. Kohoude, M.J.; Gbaguidi, F.; Agbani, P.; Ayedoun, M.A.; Cazaux, S.; Bouajila, J. Chemical composition and biological activities of extracts and essential oil of Boswellia dalzielii leaves. Pharm. Biol. 2017, 55, 33–42. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  75. Kumar, D.; Sukapaka, M.; Babu, G.D.K.; Padwad, Y. Chemical composition and in vitro cytotoxicity of essential oils from leaves and flowers of Callistemon citrinus from western himalayas. PLoS ONE 2015, 10, e0133823. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  76. Sampath, S.; Veeramani, V.; Krishnakumar, G.S.; Sivalingam, U.; Madurai, S.L.; Chellan, R. Evaluation of in vitro anticancer activity of 1,8-Cineole–containing n-hexane extract of Callistemon citrinus (Curtis) Skeels plant and its apoptotic potential. Biomed. Pharmacother. 2017, 93, 296–307. [Google Scholar] [CrossRef] [PubMed]
  77. Yang, C.; Chen, H.; Chen, H.; Zhong, B.; Luo, X.; Chun, J. Antioxidant and anticancer activities of essential oil from gannan navel orange peel. Molecules 2017, 22, 1391. [Google Scholar] [CrossRef]
  78. Hassan, S.B.; Gali-Muhtasib, H.; Göransson, H.; Larsson, R. Alpha terpineol: A potential anticancer agent which acts through suppressing NF-κB signalling. Anticancer Res. 2010, 30, 1911–1919. [Google Scholar]
  79. Brändle, G.; L’Huillier, A.G.; Wagner, N.; Gervaix, A.; Wildhaber, B.E.; Lacroix, L. First report of spontaneous peritonitis in a child. BMC Infect. Dis. 2014, 14, 719. [Google Scholar] [CrossRef] [Green Version]
  80. Pulcrano, G.; Balzaretti, M.; Grosini, A.; Piacentini, V.; Poddighe, D. First report of Kocuria marina bloodstream infection unrelated to a central venous catheter: A mini-review on an emerging and under-recognized opportunistic pathogen. Infez. Med. 2017, 25, 71–74. [Google Scholar]
  81. De Paiva Anciens Ramos, G.L.; Vigoder, H.C.; dos Santos Nascimento, J. Kocuria spp. in foods: Biotechnological uses and risks for food safety. Appl. Food Biotechnol. 2021, 8, 79–88. [Google Scholar]
  82. Thoma, R.; Seneghini, M.; Seiffert, S.N.; Vuichard Gysin, D.; Scanferla, G.; Haller, S.; Flury, D.; Boggian, K.; Kleger, G.-R.; Filipovic, M.; et al. The challenge of preventing and containing outbreaks of multidrug-resistant organisms and Candida auris during the coronavirus disease 2019 pandemic: Report of a carbapenem-resistant Acinetobacter baumannii outbreak and a systematic review of the literatu. Antimicrob. Resist. Infect. Control 2022, 11, 1–11. [Google Scholar] [CrossRef]
  83. Adewoyin, M.A.; Okoh, A.I. The natural environment as a reservoir of pathogenic and non-pathogenic Acinetobacter species. Rev. Environ. Health 2018, 33, 265–272. [Google Scholar] [CrossRef] [PubMed]
  84. Carvalheira, A.; Ferreira, V.; Silva, J.; Teixeira, P. Enrichment of Acinetobacter spp. from food samples. Food Microbiol. 2016, 55, 123–127. [Google Scholar] [CrossRef] [PubMed]
  85. Krauze-Baranowska, M.; Majdan, M.; Hałasa, R.; Głód, D.; Kula, M.; Fecka, I.; Orzeł, A. The antimicrobial activity of fruits from some cultivar varieties of Rubus idaeus and Rubus occidentalis. Food Funct. 2014, 5, 2536–2541. [Google Scholar] [CrossRef] [PubMed]
  86. Qin, Y.; Wang, L.; Liu, Y.; Zhang, Q.; Li, Y.; Wu, Z. Release of phenolics compounds from Rubus idaeus L. dried fruits and seeds during simulated in vitro digestion and their bio-activities. J. Funct. Foods 2018, 46, 57–65. [Google Scholar] [CrossRef]
  87. Sariburun, E.; Şahin, S.; Demir, C.; Türkben, C.; Uylaşer, V. Phenolic content and antioxidant activity of raspberry and blackberry cultivars. J. Food Sci. 2010, 75, C328–C335. [Google Scholar] [CrossRef]
  88. Lee, H.H.; Moon, Y.S.; Yun, H.K.; Park, P.J.; Kwak, E.J. Contents of bioactive constituents and antioxidant activities of cultivated and wild raspberries. Korean J. Hortic. Sci. Technol. 2014, 32, 115–122. [Google Scholar] [CrossRef] [Green Version]
  89. Krzepiłko, A.; Prażak, R.; Święciło, A. Chemical composition, antioxidant and antimicrobial activity of raspberry, blackberry and raspberry-blackberry hybrid leaf buds. Molecules 2021, 26, 327. [Google Scholar] [CrossRef]
  90. Guiné, R.P.F.; Soutinho, S.M.A.; Gonçalves, F.J. Phenolic compounds and antioxidant activity in red fruits produced in organic farming. Croat. J. Food Sci. Technol 2014, 6, 15–26. [Google Scholar]
  91. Mihailović, N.R.; Mihailović, V.B.; Ćirić, A.R.; Srećković, N.Z.; Cvijović, M.R.; Joksović, L.G. Analysis of wild raspberries (Rubus idaeus L.): Optimization of the ultrasonic-assisted extraction of phenolics and a new insight in phenolics bioaccessibility. Plant Foods Hum. Nutr. 2019, 74, 399–404. [Google Scholar] [CrossRef]
  92. Dos Santos, S.S.; Paraíso, C.M.; Rodrigues, L.M.; Madrona, G.S. Agro-industrial waste as a source of bioactive compounds: Ultrasound-assisted extraction from blueberry (Vaccinium myrtillus) and raspberry (Rubus idaeus) pomace. Acta Sci. Technol. 2021, 43, 1–8. [Google Scholar] [CrossRef]
  93. Çekiç, Ç.; Özgen, M. Comparison of antioxidant capacity and phytochemical properties of wild and cultivated red raspberries (Rubus idaeus L.). J. Food Compos. Anal. 2010, 23, 540–544. [Google Scholar] [CrossRef]
  94. Tosun, M.; Ercisli, S.; Karlidag, H.; Sengul, M. Characterization of red raspberry (Rubus idaeus L.) genotypes for their physicochemical properties. J. Food Sci. 2009, 74, C575–C579. [Google Scholar] [CrossRef] [PubMed]
  95. Dudzinska, D.; Luzak, B.; Boncler, M.; Rywaniak, J.; Sosnowska, D.; Podsedek, A.; Watala, C. CD39/NTPDase-1 expression and activity in human umbilical vein endothelial cells are differentially regulated by leaf extracts from Rubus caesius and Rubus idaeus. Cell. Mol. Biol. Lett. 2014, 19, 361–380. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  96. Grabek-Lejko, D.; Wojtowicz, K. Comparison of antibacterial and antioxidant properties of fruits and leaves of blackberry (Rubus plicatus) and raspberry (Rubus idaeus). J. Microbiol. Biotechnol. Food Sci. 2014, 3, 514–518. [Google Scholar]
  97. Mîrza, A. Antioxidant actiyity of leaf and fruit extracts from Rubus fruticosus, Rubus idaeus and Rubus loganobaccus growing in the conditions of the Republic of Moldova. Sci. Pap. Ser. Manag. Econ. Eng. Agric. Rural Dev. 2021, 21, 363–372. [Google Scholar]
  98. Toshima, S.; Hirano, T.; Kunitake, H. Comparison of anthocyanins, polyphenols, and antioxidant capacities among raspberry, blackberry, and Japanese wild Rubus species. Sci. Hortic. 2021, 285, 110204. [Google Scholar] [CrossRef]
  99. Kostecka-Gugała, A.; Ledwozyw-Smoleń, I.; Augustynowicz, J.; Wyzgolik, G.; Kruczek, M.; Kaszycki, P. Antioxidant properties of fruits of raspberry and blackberry grown in central Europe. Open Chem. 2015, 13, 1313–1325. [Google Scholar] [CrossRef]
  100. Ogawa, K.; Sakakibara, H.; Iwata, R.; Ishii, T.; Sato, T.; Goda, T.; Shimoi, K.; Kumazawa, S. Anthocyanin composition and antioxidant activity of the crowberry (Empetrum nigrum) and other berries. J. Agric. Food Chem. 2008, 56, 4457–4462. [Google Scholar] [CrossRef]
  101. Dvaranauskaite, A.; Venskutonis, P.R.; Labokas, J. Comparison of quercetin derivatives in ethanolic extracts of red raspberry (Rubus idaeus L.) leaves. Acta Aliment. 2008, 37, 449–461. [Google Scholar] [CrossRef]
  102. Venskutonis, P.R.; Dvaranauskaite, A.; Labokas, J. Radical scavenging activity and composition of raspberry (Rubus idaeus) leaves from different locations in Lithuania. Fitoterapia 2007, 78, 162–165. [Google Scholar] [CrossRef]
  103. Yu, R.; Chen, L.; Xin, X. Comparative assessment of chemical compositions, antioxidant and antimicrobial activity in ten berries grown in China. Flavour Fragr. J. 2020, 35, 197–208. [Google Scholar] [CrossRef]
  104. Gülçin, I.; Topal, F.; Çakmakçi, R.; Bilsel, M.; Gören, A.C.; Erdogan, U. Pomological features, nutritional quality, polyphenol content analysis, and antioxidant properties of domesticated and 3 wild ecotype forms of raspberries (Rubus idaeus L.). J. Food Sci. 2011, 76, 585–593. [Google Scholar] [CrossRef] [PubMed]
  105. Ramirez, M.R.; Apel, M.A.; Raseira, M.C.B.; Zuanazzi, J.Â.S.; Henriques, A.T. Polyphenol content and evaluation of antichemotactic, antiedematogenic and antioxidant activities of Rubus sp. cultivars. J. Food Biochem. 2011, 35, 1389–1397. [Google Scholar] [CrossRef]
  106. Değirmenci, H.; Erkurt, H. Relationship between volatile components, antimicrobial and antioxidant properties of the essential oil, hydrosol and extracts of Citrus aurantium L. flowers. J. Infect. Public Health 2020, 13, 58–67. [Google Scholar] [CrossRef] [PubMed]
  107. Flores-Soto, M.E.; Corona-Angeles, J.A.; Tejeda-Martinez, A.R.; Flores-Guzman, P.A.; Luna-Mujica, I.; Chaparro-Huerta, V.; Viveros-Paredes, J.M. β-Caryophyllene exerts protective antioxidant effects through the activation of NQO1 in the MPTP model of Parkinson’s disease. Neurosci. Lett. 2021, 742, 135534. [Google Scholar] [CrossRef] [PubMed]
  108. Lin, L.; Long, N.; Qiu, M.; Liu, Y.; Sun, F.; Dai, M. The inhibitory efficiencies of geraniol as an anti-inflammatory, antioxidant, and antibacterial, natural agent against methicillin-resistant Staphylococcus aureus infection in vivo. Infect. Drug Resist. 2021, 14, 2991–3000. [Google Scholar] [CrossRef] [PubMed]
  109. Taheri Mirghaed, A.; Fayaz, S.; Hoseini, S.M. Effects of dietary 1,8-cineole supplementation on serum stress and antioxidant markers of common carp (Cyprinus carpio) acutely exposed to ambient ammonia. Aquaculture 2019, 509, 8–15. [Google Scholar] [CrossRef]
  110. Zheljazkov, V.D.; Kacaniova, M.; Dincheva, I.; Radoukova, T.; Semerdjieva, I.B.; Astatkie, T.; Schlegel, V. Essential oil composition, antioxidant and antimicrobial activity of the galbuli of six juniper species. Ind. Crops Prod. 2018, 124, 449–458. [Google Scholar] [CrossRef]
  111. Szymanowska, U.; Baraniak, B.; Bogucka-Kocka, A. Antioxidant, Anti-Inflammatory, and Postulated Cytotoxic Activity of Phenolic and Anthocyanin-Rich Fractions from Polana Raspberry (Rubus idaeus L.) Fruit and Juice-In Vitro Study. Molecules 2018, 23, 1812. [Google Scholar] [CrossRef] [Green Version]
  112. Benvenuti, S.; Pellati, F.; Melegari, M.; Bertelli, D. Polyphenols, Anthocyanins, Ascorbic Acid, and Radical Scavenging Activity of Rubus, Ribes, and Aronia. J. Food Sci. 2004, 69, 164–169. [Google Scholar] [CrossRef]
  113. Dvaranauskaite, A.; Venskutonis, P.R.; Labokas, J. Radical scavenging activity of raspberry (Rubus idaeus L.) fruit extracts. Acta Aliment. 2006, 35, 73–83. [Google Scholar] [CrossRef]
  114. Buřičová, L.; Andjelkovic, M.; Čermáková, A.; Réblová, Z.; Jurček, O.; Kolehmainen, E.; Verhé, R.; Kvasnička, F. Antioxidant capacity and antioxidants of strawberry, blackberry, and raspberry leaves. Czech J. Food Sci. 2011, 29, 181–189. [Google Scholar] [CrossRef] [Green Version]
  115. Frías-Moreno, M.N.; Parra-Quezada, R.Á.; Ruíz-Carrizales, J.; González-Aguilar, G.A.; Sepulveda, D.; Molina-Corral, F.J.; Jacobo-Cuellar, J.L.; Olivas, G.I. Quality, bioactive compounds and antioxidant capacity of raspberries cultivated in northern Mexico. Int. J. Food Prop. 2021, 24, 603–614. [Google Scholar] [CrossRef]
  116. Costea, T.; Lupu, A.R.; Vlase, L.; Nencu, I.; Gîrd, C.E. Phenolic content and antioxidant activity of a raspberry leaf dry extract. Rom. Biotechnol. Lett. 2016, 21, 11346–11356. [Google Scholar]
  117. Gramza-Michałowska, A.; Bueschke, M.; Kulczyński, B.; Gliszczyńska-Świgło, A.; Kmiecik, D.; Bilska, A.; Purłan, M.; Wałęsa, L.; Ostrowski, M.; Filipczuk, M.; et al. Phenolic compounds and multivariate analysis of antiradical properties of red fruits. J. Food Meas. Charact. 2019, 13, 1739–1747. [Google Scholar] [CrossRef] [Green Version]
  118. Frías-Moreno, M.N.; Parra-Quezada, R.A.; González-Aguilar, G.; Ruíz-Canizales, J.; Molina-Corral, F.J.; Sepulveda, D.R.; Salas-Salazar, N.; Olivas, G.I. Quality, bioactive compounds, antioxidant capacity, and enzymes of raspberries at different maturity stages, effects of organic vs. Conventional fertilization. Foods 2021, 10, 953. [Google Scholar] [CrossRef]
  119. Gao, W.; Wang, Y.S.; Hwang, E.; Lin, P.; Bae, J.; Seo, S.A.; Yan, Z.; Yi, T.H. Rubus idaeus L. (red raspberry) blocks UVB-induced MMP production and promotes type I procollagen synthesis via inhibition of MAPK/AP-1, NF-κβ and stimulation of TGF-β/Smad, Nrf2 in normal human dermal fibroblasts. J. Photochem. Photobiol. B Biol. 2018, 185, 241–253. [Google Scholar] [CrossRef]
  120. Kafkas, E.; Ozgen, M.; Ozogul, Y.; Turemis, N. Phytochemical and Fatty Acid Profile of Selected Red Raspberry cultivars: A comparative study. J. Food Qual. 2008, 31, 67–78. [Google Scholar] [CrossRef]
  121. Wu, L.; Liu, Y.; Qin, Y.; Wang, L.; Wu, Z. HPLC-ESI-qTOF-MS/MS characterization, antioxidant activities and inhibitory ability of digestive enzymes with molecular docking analysis of various parts of raspberry (Rubus ideaus L.). Antioxidants 2019, 8, 274. [Google Scholar] [CrossRef] [Green Version]
  122. Ozarda, O.; Barla Demirkoz, A.; Özdemir, M. Sensory characteristics and antioxidant capacity of red raspberry extract as a preservative in fruity flavoured beverages. J. Food Sci. Technol. 2015, 52, 6687–6694. [Google Scholar] [CrossRef] [Green Version]
  123. Radočaj, O.; Vujasinović, V.; Dimić, E.; Basić, Z. Blackberry (Rubus fruticosus L.) and raspberry (Rubus idaeus L.) seed oils extracted from dried press pomace after longterm frozen storage of berries can be used as functional food ingredients. Eur. J. Lipid Sci. Technol. 2014, 116, 1015–1024. [Google Scholar] [CrossRef]
  124. Parry, J.; Su, L.; Luther, M.; Zhou, K.; Peter Yurawecz, M.; Whittaker, P.; Yu, L. Fatty acid composition and antioxidant properties of cold-pressed marionberry, boysenberry, red raspberry, and blueberry seed oils. J. Agric. Food Chem. 2005, 53, 566–573. [Google Scholar] [CrossRef]
  125. Golmohamadi, A.; Möller, G.; Powers, J.; Nindo, C. Effect of ultrasound frequency on antioxidant activity, total phenolic and anthocyanin content of red raspberry puree. Ultrason. Sonochem. 2013, 20, 1316–1323. [Google Scholar] [CrossRef] [PubMed]
  126. Miletic, N.; Leposavic, A.; Popovic, B.; Mitrovic, O.; Kandic, M. Chemical and antioxidant properties of fully matured raspberry fruits (Rubus idaeus L.) picked in different moments of harvesting season. Acta Hortic. 2015, 1099, 211–218. [Google Scholar] [CrossRef]
  127. Marhuenda, J.; Alemán, M.D.; Gironés-vilaplana, A.; Pérez, A.; Caravaca, G.; Figueroa, F.; Mulero, J.; Zafrilla, P. Phenolic Composition, Antioxidant Activity, and In Vitro Availability of Four Different Berries. J. Chem. 2016, 7. [Google Scholar]
  128. Farias-Cervantes, V.S.; Chávez-Rodríguez, A.; García-Salcedo, P.A.; García-López, P.M.; Casas-Solís, J.; Andrade-González, I. Antimicrobial effect and in vitro release of anthocyanins from berries and Roselle obtained via microencapsulation by spray drying. J. Food Process. Preserv. 2018, 42, 1–8. [Google Scholar] [CrossRef]
  129. Xu, Y.; Li, L.Z.; Cong, Q.; Wang, W.; Qi, X.L.; Peng, Y.; Song, S.J. Bioactive lignans and flavones with in vitro antioxidant and neuroprotective properties from Rubus idaeus rhizome. J. Funct. Foods 2017, 32, 160–169. [Google Scholar] [CrossRef]
  130. Konić-Ristić, A.; Šavikin, K.; Zdunić, G.; Janković, T.; Juranic, Z.; Menković, N.; Stanković, I. Biological activity and chemical composition of different berry juices. Food Chem. 2011, 125, 1412–1417. [Google Scholar] [CrossRef]
  131. Krivokapić, S.; Vlaović, M.; Vratnica, B.D.; Perović, A.; Perovic, S. Biowaste as a potential source of bioactive compound-a case study of raspberry fruit pomace. Foods 2021, 10, 706. [Google Scholar] [CrossRef]
  132. Malone, N. Strawberries-Cultivation, Antioxidant Properties and Health Benefits; Nova Publishers: New York, NY, USA, 2014; ISBN 9781631172557. [Google Scholar]
  133. Zorzi, M.; Gai, F.; Medana, C.; Aigotti, R.; Morello, S.; Peiretti, P.G. Bioactive Compounds and Antioxidant Capacity of Small Berries. Foods 2020, 9, 623. [Google Scholar] [CrossRef]
  134. Zhang, L.; Li, J.; Hogan, S.; Chung, H.; Welbaum, G.E.; Zhou, K. Inhibitory effect of raspberries on starch digestive enzyme and their antioxidant properties and phenolic composition. Food Chem. 2010, 119, 592–599. [Google Scholar] [CrossRef]
  135. Connor, A.M.; Stephens, M.J.; Hall, H.K.; Alspach, P.A. Variation and heritabilities of antioxidant activity and total phenolic content estimated from a red raspberry factorial experiment. J. Am. Soc. Hortic. Sci. 2005, 130, 40. [Google Scholar] [CrossRef] [Green Version]
Figure 1. Total ion chromatogram (TIC) of a hexan extract of raspberry leaves steam-distilled.
Figure 1. Total ion chromatogram (TIC) of a hexan extract of raspberry leaves steam-distilled.
Foods 11 01455 g001
Figure 2. Antiproliferative activity after 48 h of treatment with RH tested on MCF10A, HL60, and Caco2 cell lines. The standard deviation is represented by black bars. Bars with different letters indicate a significant difference at p < 0.05 among cell lines, according to a one-way analysis of variance (ANOVA) for multiple comparisons applying the Tukey test.
Figure 2. Antiproliferative activity after 48 h of treatment with RH tested on MCF10A, HL60, and Caco2 cell lines. The standard deviation is represented by black bars. Bars with different letters indicate a significant difference at p < 0.05 among cell lines, according to a one-way analysis of variance (ANOVA) for multiple comparisons applying the Tukey test.
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Table 1. Total volatile organic compound (VOC) profiles for the distillate of raspberry leaves by HS-GC/MS. LRI: Linear Retention Indices measured on a polar column; LRIlit: Linear Retention Indices from literature.
Table 1. Total volatile organic compound (VOC) profiles for the distillate of raspberry leaves by HS-GC/MS. LRI: Linear Retention Indices measured on a polar column; LRIlit: Linear Retention Indices from literature.
PeakLRILRIlitComponentClassAmount (%)
1915914butanal, 3-methylAldehyde0.2
2970968pentanalAldehyde2.9
39959932,3-butanedioneKetone0.4
4102510222-butanolAlcohol0.4
5109310951-propanol, 2-methyl-Alcohol0.4
6114811463-careneMonoterpene16.3
711601157β-myrceneMonoterpene0.1
812001198limoneneMonoterpene1.0
9121012071-butanol, 2-methyl-Alcohol1.6
10121412091,8-cineoleOxygenated monoterpene50.8
11129812962-heptanolAlcohol10.3
12139513893-hexen-1-olAlcohol1.5
13139813942-hexen-1-olAlcohol0.2
14147214695-hepten-2-ol, 6-methyl-Alcohol0.9
1515311528camphorOxygenated monoterpene2.9
1615851586hotrienolAlcohol0.2
1716181619terpinyl acetateOxygenated monoterpene3.7
1816761675α-terpineolOxygenated monoterpene5.2
1920142011methyl eugenolPhenylpropanoid0.5
Total 99.0
Table 2. Volatile fraction composition of raspberry leaves hydrolate hexanoic extract determined by GC/MS. 1 LRI: Linear Retention Indices.
Table 2. Volatile fraction composition of raspberry leaves hydrolate hexanoic extract determined by GC/MS. 1 LRI: Linear Retention Indices.
PeakLRI 1CompoundClassAmount (%)
18292-hexenalAldehyde8.79
28662-heptanoneKetone1.49
38762-hexanol-3-methylAlcohol1.59
49144-heptanol-3-ethylAlcohol1.56
59243-hexanol-5-methylAlcohol1.26
69692,4 heptadienalAldehyde3.13
79841,8-cineoleOxygenated monoterpene2.47
810292-nonanoneKetone6.88
91035β-linaloolOxygenated monoterpene6.15
101135geraniolOxygenated monoterpene4.45
111145citralTerpenoid1.00
121162unknown-1.68
131195methyl salicylateEster1.94
141198n-decanoic acidAcid1.15
151210unknown-6.71
161256unknown-2.80
171269unknown-2.11
181281α-terpinen-7-alMonoterpenoid1.19
191289unknown-1.15
201308unknown-6.65
211352dodecanoic acidAcid1.37
221410τ-muurololSesquiterpene1.09
231437unknown-3.30
241466caryophylleneSesquiterpene2.61
Total identified 72.52
Table 3. Antibacterial activity of 10 µL of pure RH and 10 µL of Gentamicin (1 mg/mL) evaluated using the agar diffusion method. NE: No Effect.
Table 3. Antibacterial activity of 10 µL of pure RH and 10 µL of Gentamicin (1 mg/mL) evaluated using the agar diffusion method. NE: No Effect.
Agar Diffusion MethodRH (10 µL)
Inhibition Halo (mm) ± sd (mm)
Gentamicin (10 µL)
Inhibition Halo (mm) ± sd (mm)
E. coliNE24.8 ± 0.4
K. marinaNE26 ± 6
P. fluorescensNE22 ± 1
B. cereus7.67 ± 122 ± 3
A. bohemicus12 ± 334 ± 2
Table 4. Total Phenols Content (TPC), expressed as mg GAE 100 mL−1, and the antioxidant capacity of RH in three different tests: DPPH, ABTS, and FRAP. Antioxidant values are expressed as µM of Trolox Equivalent 100 mL−1 of RH used in the assay.
Table 4. Total Phenols Content (TPC), expressed as mg GAE 100 mL−1, and the antioxidant capacity of RH in three different tests: DPPH, ABTS, and FRAP. Antioxidant values are expressed as µM of Trolox Equivalent 100 mL−1 of RH used in the assay.
TPCDPPHABTSFRAP
RH6.25 ± 0.546746 ± 55513.57 ± 0.56307.48 ± 3.08
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De Santis, D.; Carbone, K.; Garzoli, S.; Laghezza Masci, V.; Turchetti, G. Bioactivity and Chemical Profile of Rubus idaeus L. Leaves Steam-Distillation Extract. Foods 2022, 11, 1455. https://doi.org/10.3390/foods11101455

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De Santis D, Carbone K, Garzoli S, Laghezza Masci V, Turchetti G. Bioactivity and Chemical Profile of Rubus idaeus L. Leaves Steam-Distillation Extract. Foods. 2022; 11(10):1455. https://doi.org/10.3390/foods11101455

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De Santis, Diana, Katya Carbone, Stefania Garzoli, Valentina Laghezza Masci, and Giovanni Turchetti. 2022. "Bioactivity and Chemical Profile of Rubus idaeus L. Leaves Steam-Distillation Extract" Foods 11, no. 10: 1455. https://doi.org/10.3390/foods11101455

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