Search Results (8)

Six solvent fractions isolated from flower bud and leaf ethanolic extracts of Cleistocalyx operculatus were analyzed for their phytochemical contents, including phenolics, flavonoids, saponins, tannins, and alkaloids. Antioxidant activities were measured using the ABTS, DPPH, and FRAP assays. The results showed that the flower bud aqueous fraction (BAF) and the leaf aqueous fraction (LAF) rich in phenolic content (768.18 and 490.74 mg GAE/g dry extract, respectively) exhibited significantly higher antioxidant activities than the other fractions. The flower bud hexane fraction (BHF) had remarkably high flavonoid and saponin contents (134.77 mg QE/g and 153.33 mg OA/g dry extract, respectively), followed by that of the leaf hexane fraction (LHF) (76.54 mg QE/g and 88.25 mg OA/g dry extract, respectively). The BHF and LHF were found to have extremely high antibacterial activity against two H. pylori strains, ATCC 51932 and 43504 (MICs of 125 µg/mL). Interestingly, DMC (2′,4′-Dihydroxy-6′-methoxy-3′,5′-dimethylchalcone) isolated from the BHF displayed greater antibacterial activity against the bacterial strains (MICs of 25–50 µg/mL) than those of the fractions. In addition, DMC presented potent inhibitory effects on H. pylori urease (IC₅₀ of 3.2 µg/mL) and α-amylase (IC₅₀ of 83.80 µg/mL), but no inhibition against α-glucosidase. It was also demonstrated that DMC showed pronounced inhibitory effects on the urease activity and biofilm formation of H. pylori, and could increase the membrane permeability of the bacterial cells. Scanning electron micrographs depicted that the BHF and DMC had strong effects on the cell shape and significantly induced the distortion and damage of the cell membrane. The fractions and DMC showed no significant toxicity to four tested human cell lines. Efforts to reduce antibiotic use indicate the need for further studies of the flower buds and DMC as potential products to prevent or treat gastric H. pylori infections. Full article

Chalcones constitute an important group of natural compounds abundant in fruits and comestible plants. They are a subject of increasing interest because of their biological activities, including anti-diabetic and anti-obesity effects. The simple chalcone structural scaffold can be modified at multiple sites with different chemical moieties. Here, we generated an artificial chalcone, i.e., 3,5-dimethyl-2,4,6-trimethoxychalcone (TriMetChalc), derived from 2′,4′-Dihydroxy-6′-methoxy-3′,5′-dimethylchalcone (DMC). DMC is a major compound of Cleistocalyx operculatus, a plant widely used in Asia for its anti-hyperglycemic activity. Using ob/ob mice as an obesity model, we report that, after 3 weeks of per os administration, TriMetChalc modified food intake through the specific activation of brain structures dedicated to the regulation of energy balance. TriMetChalc also decreased weight gain, glucose intolerance, and hepatic steatosis. Moreover, through extensive liver lipidomic analysis, we identified TriMetChalc-induced modifications that could contribute to improving the liver status of the animals. Hence, TriMetChalc is a chalcone derivative capable of reducing food intake and the addition of glucose intolerance and hepatic steatosis in a mouse model of obesity. In light of these results, we believe that TriMetChalc action deserves to be more deeply evaluated over longer treatment periods and/or in combination with other chalcones with protective effects on the liver. Full article

As part of our ongoing research on new anti-diabetic compounds from ethnopharmacologically consumed plants, two previously undescribed lupane-type triterpenoids (1 and 2) with dicarboxylic groups, an undescribed nor-taraxastane-type triterpenoid (3), and 14 known compounds (4–17) were isolated from the leaves of Cleistocalyx operculatus. Extensive spectroscopic analysis (IR, HRESIMS, 1D, and 2D NMR) was used for structure elucidation, while the known compounds were compared to reference data reported in the scientific literature. All the isolates (1–17) were evaluated for their inhibitory effects on the protein tyrosine phosphatase 1B (PTP1B) enzyme. Compounds 6, 9, and 17 showed strong PTP1B inhibitory activities. The mechanism of PTP1B inhibition was studied through enzyme kinetic experiments. A non-competitive mechanism of inhibition was determined using Lineweaver–Burk plots for compounds 6, 9, and 17. Additionally, Dixon plots were employed to determine the inhibition constant. Further insights were gained through a structure–activity relationship study and molecular docking analysis of isolated compounds with the PTP1B crystal structure. Moreover, all isolates (1–17) were tested for their stimulatory effects on the uptake of 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]-D-glucose (2-NBDG) in differentiated 3T3-L1 adipocyte cells. Compounds 6, 13, and 17 exhibited strong glucose absorption stimulation activity in a dose-dependent manner. Full article

In this study, chemical components, α-glucosidase inhibitory activities, and molecular modelling studies of the essential oil extracted from the Cleistocalyx operculatus leaves were investigated. In total, thirty compounds were identified using GC/MS, representing 98.3% of the oil. Of these, the two most dominant constituents of the essential oil were determined as (Z)-β-ocimene (30.4%) and allo-ocimene (31.6%). The α-glucosidase inhibitory experiments indicated that the essential oil exhibited potent α-glucosidase inhibitory activities, with IC₅₀ values of 61.82 ± 3.91 µg/mL. For further investigation into inhibitory mechanisms, molecular docking simulations were performed to investigate structural interactions between two dominant constituents and the α-glucosidase protein. The simulation revealed that allo-ocimene (31.6%) and (Z)-β-ocimene (30.4%) have protein binding affinities of −5.358 and −5.330 kcal/mol, respectively. Moreover, molecular dynamic simulation indicated that the complexes of two compounds and the target protein were stable over 100 ns. Overall, these findings suggest that the essential oil of C. operculatus leaves could be a natural source of potential α-glucosidase inhibitors. Full article

(1) Background: Many human diseases are associated with oxidative stress, which is caused by reactive oxygen species and free radicals generated in living cells. Some biomass extracts derived from various types of plants can act as efficient drugs against pathological disorders related to oxidative stress. Numerous herbal blends have thus been shown to improve health. Cleistocalyx operculatus (Roxb.) Merr. and L.M.Perry teas have been considered in that way. Problem: Because of amertume, the taste of C. operculatus avoids or limits a large use of such alleged healthy leaf infusions. (2) Methods: The phytochemistry, oxygen, free radical scavenging activity, and antilipid peroxidation of C. operculatus teas were here studied in vitro. Then different mixes of C. operculatus and Mentha arvensis were infused together and tasted in a hedonic test. The chemical and biological properties of the best mix were then analyzed. (3) Results: The herbal blend of C. operculatus revealed significant scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) with IC₅₀ values of 35.6 µg/mL. Induced by hydroxyl radicals, this beverage could significantly inhibit the lipid peroxidation of mouse brain homogenates. Our results demonstrate that the lipid peroxidation inhibition of dried leaves of C. operculatus might be related to its scavenging effects on oxygen free radicals. This C. operculatus bitter blend was then combined with various amounts of M. arvensis Linn. The taste was evaluated, and further biochemical analyses were conducted on the best 7/3 ratio. They showed that the healthy properties were maintained. (4) Conclusion: The optimized 7/3 ratio of the Cleistocalyx/Mentha mix led to the best results in terms of taste (sensory tests). It is demonstrated that the potential health benefits against oxidative stress remained high as compared with pure C. operculatus infusion. Full article

Neighboring relationships among plants have been extensively reported, but little is known about the effect of waterlogging. In this study, Cleistocalyx operculatus (Roxb.) Merr. and Dalbergia odorifera T. Chen saplings were used in investigating the neighboring relationships between legumes and non-leguminous woody plants under different planting and watering regimes. Results showed that C. operculatus and D. odorifera are waterlogging-tolerant species, and C. operculatus with high proportion of adventitious roots would be at an advantage during waterlogging. The growth performance of D. odorifera was better than that of C. operculatus under well-watered single-planting conditions. However, under well-watered mixed-planting conditions, C. operculatus had an obvious inhibitory effect on the growth traits (increments in stem height and leaf number, total leaf area, and total plant fresh weight) and physiological responses (net photosynthesis rate, stomatal conductance, and transpiration) of D. odorifera, whereas the growth of C. operculatus slightly increased in the presence of D. odorifera. Under waterlogging mixed-planting conditions, the facilitative effect was more intensive; the total leaf area, underground fresh weight, and total plant fresh weight of C. operculatus significantly increased, but a negative effect was found in D. odorifer. These results showed that the neighboring relationship between these two species is predominantly favorable to C. operculatus. This research sheds new light on screening waterlogging-tolerant arbor species and species collocation during vegetation restoration and reconstruction activities in wetland systems. Full article

Green synthesis has recently attracted extensive attention from scientists all over the world for the production of metal nanoparticles. Selenium nanoparticles (Se NPs) have been demonstrated as a suitable supplement nutrient for the replacement of selenium ions in terms of safety and efficiency. This work presented a friendly and facile approach to synthesize the Se NPs using polyphenols content in the Cleistocalyx operculatus (CO) leaves extract. The synthesizing conditions were optimized to obtain the Se NPs with uniform distribution and shape. The prepared Se NPs were well-characterized using scanning electron microscopy, X-ray diffraction, energy diffractive spectroscopy, and Fourier-transform infrared spectroscopy. The resultant Se NPs were in spherical shape with the particle size in a range from 50–200 nm. The antimicrobial properties of Se NPs were investigated against Echerichia coli and Staphylococcus aureus, which showed reasonable activity. The acute oral toxicity of Se NPs in mice was also studied. The result indicated that Se NPs exhibited lower toxicity than that of SeO₂ with the lethal concentration (50% death of mice) of 7.75 mg kg⁻¹_. Full article

2′,4′-Dihydroxy-6’-methoxy-3′,5′-dimethylchalcone (DMC), a principal natural chalcone of Cleistocalyx operculatus buds, suppresses the growth of many types of cancer cells. However, the effects of this compound on pancreatic cancer cells have not been evaluated. In our experiments, we explored the effects of this chalcone on two human pancreatic cancer cell lines. A cell proliferation assay revealed that DMC exhibited concentration-dependent cytotoxicity against PANC-1 and MIA PACA2 cells, with IC₅₀ values of 10.5 ± 0.8 and 12.2 ± 0.9 µM, respectively. Treatment of DMC led to the apoptosis of PANC-1 by caspase-3 activation as revealed by annexin-V/propidium iodide double-staining. Western blotting indicated that DMC induced proteolytic activation of caspase-3 and -9, degradation of caspase-3 substrate proteins (including poly[ADP-ribose] polymerase [PARP]), augmented bak protein level, while attenuating the expression of bcl-2 in PANC-1 cells. Taken together, our results provide experimental evidence to support that DMC may serve as a useful chemotherapeutic agent for control of human pancreatic cancer cells. Full article