Search Results (15)

Molecular hybridization is a widely used strategy in drug discovery and development processes that consists of the combination of two bioactive compounds toward a novel entity. In the current study, two libraries of hybrid derivatives coming from the linkage of sesquiterpene counterparts dihydroartemisinin and artesunic acid, with a series of monoterpenes, were synthesized and evaluated by cell viability assay on primary and metastatic melanoma cell lines. Almost all the obtained compounds showed micromolar antimelanoma activity and selectivity toward the metastatic form of this cancer. Four hybrid derivatives containing perillyl alcohol, citronellol, and nerol as monoterpene counterpart emerged as the best compounds of the series, with nerol being active in combination with both sesquiterpenes, dihydroartemisinin and artesunic acid. Preliminary studies on the mechanism of action have shown the dependence of the pharmacological activity of newly synthesized hybrids on the formation of carbon- and oxygen-centered radical species. This study demonstrated the positive modulation of the pharmacodynamic effect of artemisinin semisynthetic derivatives dihydroartemisinin and artesunic acid due to the hybridization with monoterpene counterparts. Full article

A novel series of nitrostyrene-based spirooxindoles were synthesized via the reaction of substituted isatins 1a–b, a number of α-amino acids 2a–e and (E)-2-aryl-1-nitroethenes 3a–e in a chemo/regio-selective manner using [3+2] cycloaddition (Huisgen) reaction under microwave irradiation conditions. The structure elucidation of all the synthesized spirooxindoles were done using ¹H and ¹³C NMR and HRMS spectral analysis. The single crystal X-ray crystallographic study of compound 4l was used to assign the stereochemical arrangements of the groups around the pyrrolidine ring in spiro[pyrrolidine-2,3′-oxindoles] skeleton. The in vitro anticancer activity of spiro[pyrrolidine-2,3′-oxindoles] analogs 4a–w against human lung (A549) and liver (HepG2) cancer cell lines along with immortalized normal lung (BEAS-2B) and liver (LO2) cell lines shows promising results. Out of the 23 synthesized spiro[pyrrolidine-2,3′-oxindoles], while five compounds (4c, 4f, 4m, 4q, 4t) (IC₅₀ = 34.99–47.92 µM; SI = 0.96–2.43) displayed significant in vitro anticancer activity against human lung (A549) cancer cell lines, six compounds (4c, 4f, 4k, 4m, 4q, 4t) (IC₅₀ = 41.56–86.53 µM; SI = 0.49–0.99) displayed promising in vitro anticancer activity against human liver (HepG2) cancer cell lines. In the case of lung (A549) cancer cell lines, these compounds were recognized to be more efficient and selective than standard reference artemisinin (IC₅₀ = 100 µM) and chloroquine (IC₅₀ = 100 µM; SI: 0.03). However, none of them were found to be active as compared to artesunic acid [IC₅₀ = 9.85 µM; SI = 0.76 against lung (A549) cancer cell line and IC₅₀ = 4.09 µM; SI = 2.01 against liver (HepG2) cancer cell line]. Full article

Helicobacter pylori is the primary pathogen responsible for causing gastroduodenal ulcers and stomach cancer. The standard treatment for H. pylori typically involves a combination of antibiotics and acid-reducing medications. However, the recurrence of ulcers is closely linked to the emergence of antibiotic resistance in H. pylori, necessitating the development of alternative drugs. This report focuses on the investigation of artesunate as a potential alternative to reduce antibiotic use and enhance effectiveness against H. pylori. Unfortunately, commercial artesunate is available in an acid form, which has poor solubility, especially in gastric acid fluid. The aim of this study is to utilize a water-soluble formulation of artesunate called dry emulsion formulation (ADEF) and combine it with amoxicillin to eradicate H. pylori. In vitro studies were conducted to evaluate the activity of ADEF against H. pylori and determine its inhibitory concentrations. In addition, pharmacokinetic parameters of orally administered ADEF and native artesunate were investigated in rats for in vivo studies. The results showed that when combined with amoxicillin and pantoprazole, ADEF exhibited effectiveness against H. pylori. It is worth noting that the solubility of ADEF in gastric acid appears to be a critical factor for achieving successful treatment. Consequently, ADEF could be considered a promising candidate for H. pylori therapy. Full article

Human Topoisomerase I (hTop1p) is a ubiquitous enzyme that relaxes supercoiled DNA through a conserved mechanism involving transient breakage, rotation, and binding. Htop1p is the molecular target of the chemotherapeutic drug camptothecin (CPT). It causes the hTop1p-DNA complex to slow down the binding process and clash with the replicative machinery during the S phase of the cell cycle, forcing cells to activate the apoptotic response. This gives hTop1p a central role in cancer therapy. Recently, two artesunic acid derivatives (compounds c6 and c7) have been proposed as promising inhibitors of hTop1p with possible antitumor activity. We used several computational approaches to obtain in silico confirmations of the experimental data and to form a comprehensive dynamic description of the ligand-receptor system. We performed molecular docking analyses to verify the ability of the two new derivatives to access the enzyme-DNA interface, and a classical molecular dynamics simulation was performed to assess the capacity of the two compounds to maintain a stable binding pose over time. Finally, we calculated the noncovalent interactions between the two new derivatives and the hTop1p receptor in order to propose a possible inhibitory mechanism like that adopted by CPT. Full article

The malaria parasite Plasmodium falciparum (Pf) can sequester in the placenta resulting in low density of peripheral parasitemia and consequently in false negative malaria diagnosis (by microscopy) in pregnant women. Moreover, the use of rapid diagnostic tests (RDTs) in diagnostic strategies, including those for the detection of a malaria infection during pregnancy, is constrained by either persistent malaria antigen (histidine-rich protein 2; HRP2) after successful treatment, leading to false positive test results, or by false negative results as previously mentioned due to parasite sequestration (which is further exacerbated due to the low limited of detection [LoD] of conventional RDTs) or to HRP2 deletion. Recently, a direct blood polymerase chain reaction combined with a nucleic acid lateral flow immunoassay (dbPCR-NALFIA) has been developed, which circumvents these challenges and has demonstrated its diagnostic potential in phase 1 and 2 studies. The PREG-DIAGMAL trial presented in this manuscript will assess the diagnostic performance of dbPCR-NALFIA for the diagnostic of malaria in pregnant women and its potential to monitor treatment efficacy in these subjects. The work is ancillary embedded in an ongoing EDCTP funded trial, the PyraPreg project (PACTR202011812241529) in which the safety and efficacy of a newly registered Artemisinin-Based Combination (Pyronaridine-Artesunate) is being evaluated in pregnant women. This is a Phase 3 diagnostic evaluation conducted in 2 African countries: Democratic Republic of the Congo (DRC) and Burkina Faso. Pregnant women fulfilling the inclusion criteria of the PyraPreg study will be also invited to participate in the PREG-DIAGMAL study. Diagnostic accuracy will be assessed following the WHO/TDR guidelines for the evaluation of diagnostics and reported according to STARD principles. Due to the lack of a 100% specific and sensitive standard diagnostic test for malaria, the sensitivity and specificity of the new test will be compared to the available diagnostic practice in place at the selected settings (microscopy and/or RDT) and to quantitative PCR as the reference test. This phase 3 diagnostic study is designed towards the evaluation of the performance of a new diagnostic tool for the screening of malaria and the monitoring of treatment in pregnant women under real conditions life. If successful, the dbPCR-NALFIA could be a valuable tool to add to the diagnostic arsenal for malaria, in particular during pregnancy. Trial registration: Pan African Clinical Trial Registry database (PACTR202203780981413). Registered on 17 March 2022. Full article

Multiple myeloma (MM) remains an incurable tumor due to the high rate of relapse that still occurs. Acquired drug resistance represents the most challenging obstacle to the extension of survival and several studies have been conducted to understand the mechanisms of this phenomenon. Mitochondrial pathways have been extensively investigated, demonstrating that cancer cells become resistant to drugs by reprogramming their metabolic assessment. MM cells acquire resistance to proteasome inhibitors (PIs), activating protection programs, such as a reduction in oxidative stress, down-regulating pro-apoptotic, and up-regulating anti-apoptotic signals. Knowledge of the mechanisms through which tumor cells escape control of the immune system and acquire resistance to drugs has led to the creation of new compounds that can restore the response by leading to cell death. In this scenario, based on all literature data available, our review represents the first collection of anti-mitochondrial compounds able to overcome drug resistance in MM. Caspase-independent mechanisms, mainly based on increased oxidative stress, result from 2-methoxyestradiol, Artesunate, ascorbic acid, Dihydroartemisinin, Evodiamine, b-AP15, VLX1570, Erw-ASNase, and TAK-242. Other agents restore PIs’ efficacy through caspase-dependent tools, such as CDDO-Im, NOXA-inhibitors, FTY720, GCS-100, LBH589, a derivative of ellipticine, AT-101, KD5170, SMAC-mimetics, glutaminase-1 (GLS1)-inhibitors, and thenoyltrifluoroacetone. Each of these substances improved the efficacy rates when employed in combination with the most frequently used antimyeloma drugs. Full article

Betulinic acid (BA, 3β-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic triterpene acid present predominantly in Betula ssp. (Betulaceae) and is also widely spread in many species belonging to different plant families. BA presents a wide spectrum of remarkable pharmacological properties, such as cytotoxic, anti-HIV, anti-inflammatory, antidiabetic and antimicrobial activities, including antiprotozoal effects. The present review first describes the sources of BA and discusses the chemical strategies to produce this molecule starting from betulin, its natural precursor. Next, the antiprotozoal properties of BA are briefly discussed and the chemical strategies for the synthesis of analogues displaying antiplasmodial, antileishmanial and antitrypanosomal activities are systematically presented. The antiplasmodial activity described for BA was moderate, nevertheless, some C-3 position acylated analogues showed an improvement of this activity and the hybrid models—with artesunic acid—showed the most interesting properties. Some analogues also presented more intense antileishmanial activities compared with BA, and, in addition to these, heterocycles fused to C-2/C-3 positions and amide derivatives were the most promising analogues. Regarding the antitrypanosomal activity, some interesting antitrypanosomal derivatives were prepared by amide formation at the C-28 carboxylic group of the lupane skeleton. Considering that BA can be produced either by isolation of different plant extracts or by chemical transformation of betulin, easily obtained from Betula ssp., it could be said that BA is a molecule of great interest as a starting material for the synthesis of novel antiprotozoal agents. Full article

Current therapy for visceral leishmaniasis (VL), compromised by drug resistance, toxicity, and high cost, demands for more effective, safer, and low-cost drugs. Artemisinin has been found to be an effectual drug alternative in experimental models of leishmaniasis. Comparative genome and transcriptome analysis of in vitro-adapted artesunate-resistant (K133AS-R) and -sensitive wild-type (K133WT) Leishmania donovani parasites was carried out using next-generation sequencing and single-color DNA microarray technology, respectively, to identify genes and interlinked pathways contributing to drug resistance. Whole-genome sequence analysis of K133WT vs. K133AS-R parasites revealed substantial variation among the two and identified 240 single nucleotide polymorphisms (SNPs), 237 insertion deletions (InDels), 616 copy number variations (CNVs) (377 deletions and 239 duplications), and trisomy of chromosome 12 in K133AS-R parasites. Transcriptome analysis revealed differential expression of 208 genes (fold change ≥ 2) in K133AS-R parasites. Functional categorization and analysis of modulated genes of interlinked pathways pointed out plausible adaptations in K133AS-R parasites, such as (i) a dependency on lipid and amino acid metabolism for generating energy, (ii) reduced DNA and protein synthesis leading to parasites in the quiescence state, and (iii) active drug efflux. The upregulated expression of cathepsin-L like protease, amastin-like surface protein, and amino acid transporter and downregulated expression of the gene encoding ABCG2, pteridine receptor, adenylatecyclase-type receptor, phosphoaceylglucosamine mutase, and certain hypothetical proteins are concordant with genomic alterations suggesting their potential role in drug resistance. The study provided an understanding of the molecular basis linked to artemisinin resistance in Leishmania parasites, which may be advantageous for safeguarding this drug for future use. Full article

Artesunate was well known as an antimalarial drug. Our previous research found that it has hypolipidemia effects in rabbits fed with a high-fat diet, especially combined with ursolic acid. In this study, we reconfirmed the lipid-lowering effect of artesunate and ursolic acid in hamsters and analyzed the metabolic changes using gas chromatography time-of-flight mass spectrometry (GC/TOF MS). Compared with the model group, a variety of different metabolites of artesunate and ursolic acid, alone or in combination, were found and confirmed. These differential metabolites, including fatty acids, lipids, and amino acids, were involved in lipid metabolism, energy metabolism, and amino acid metabolism. It indicated that two agents of artesunate and ursolic acid could attenuate or normalize the metabolic transformation on these metabolic pathways. Full article

Artemisinin and its derivatives, including artesunate (ART) and artemether (ARM), exert anticancer effects in the micromolar range in drug and radiation-resistant cell lines. Artemisinin has been reported to sensitize cervical cancer cells to radiotherapy. In the present study, we determined whether ART and ARM could enhance the cytotoxicity of 5-aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT) against the mammary tumor cells of mice. The corrected PpIX fluorescence intensities in the control, 5-ALA, 5-ALA + ART, and 5-ALA + ARM groups were 3.385 ± 3.730, 165.7 ± 33.45, 139.0 ± 52.77, and 165.4 ± 51.10 a.u., respectively. At light doses of 3 and 5 J/cm², the viability of 5-ALA-PDT-treated cells significantly decreased with ART (p < 0.01 and p < 0.01) and ARM treatment (p < 0.01 and p < 0.01). Besides, the number of annexin V-FITC and ethidium homodimer III-positive cells was greater in the 5-ALA-PDT with ARM group than that in the other groups. N-acetylcysteine could not significantly inhibit the percentages of apoptotic cells or inviable cells induced by 5-ALA-PDT with ARM. These reactive oxygen species-independent mechanisms might enhance cytotoxicity in 5-ALA-PDT with ARM-treated tumor cells, suggesting that the use of 5-ALA-PDT with ARM could be a new strategy to enhance PDT cytotoxicity against tumor cells. However, as these results are only based on in vitro studies, further in vivo investigations are required. Full article

Dengue infections are still a worldwide burden, especially in Indonesia. There is no specific medication against the dengue virus. Recently, many types of research have been conducted to discover a new drug for dengue virus using natural resource extracts. Indonesia, as a tropical country, has a wide biodiversity. There are several medicinal plants in Indonesia that are believed to possess anti-dengue activity, such as Myristica fatua, Cymbopogon citratus, and Acorus calamus plants. We conducted an in vitro laboratory experiment of several extracts from Indonesian herbs combined with in silico analysis. The extracts were evaluated for safety and antiviral activity in Huh7it-1 cell lines, using a single dose of 20 µg/mL and dose-dependent (5, 10, 20, 40, 80 and 160 µg/mL) of plant extracts against dengue virus serotype 2 (DENV-2) NGC strain. The DMSO 0.1% was used as a negative control. The cytotoxic aspect was assessed by counting the cell viability, while the antiviral activity was calculated by counting the average inhibition. The selectivity index (SI) of plant extracts were performed from a ratio of CC₅₀/EC₅₀ value. In silico analysis was conducted to determine the free energy of binding between NS5 of dengue virus with bioactive compounds contained in Myristica fatua, Cymbopogon citratus and Acorus calamus extract plants. We determined that all extracts were not toxic against Huh7it-1 cell lines. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed inhibition of DENV-2 at a dose of 20 µg/mL to 96.5%, 98.9%, and 122.7%, respectively. The dose-dependent effects showed that M. fatua has the best inhibition activity towards DENV-2. Molecular docking result showed that artesunic acid within M. fatua has the best free energy of binding (−7.2 kcal/mol), followed by homoegonol (−7.1 kcal/mol) which was slightly different from artesunic acid among others. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed prospective anti-dengue activities both in vitro and in silico. Future research should be conducted to find the pure extracts of all useful herbs as a new candidate of antiviral drug. Full article

Two major obstacles for successful cancer treatment are the toxicity of cytostatics and the development of drug resistance in cancer cells during chemotherapy. Acquired or intrinsic drug resistance is responsible for almost 90% of treatment failure. For this reason, there is an urgent need for new anticancer drugs with improved efficacy against cancer cells, and with less toxicity on normal cells. There are impressive examples demonstrating the success of natural plant compounds to fight cancer, such as Vinca alkaloids, taxanes, and anthracyclines. Artesunic acid (ARTA), a drug for malaria treatment, also exerts cytotoxic activity towards cancer cells. Multidrug resistance often results from drug efflux pumps (ABC-transporters) that reduce intracellular drug levels. Hence, it would be interesting to know, whether ARTA could overcome drug resistance of tumor cells, and in what way ABC-transporters are involved. Different derivatives showing improved features concerning cytotoxicity and pharmacokinetic behavior have been developed. Considering both drug sensitivity and resistance, we chose a sensitive and a doxorubicin-resistant leukemia cell line and determined the killing effect of ARTA on these cells. Molecular docking and doxorubicin efflux assays were performed to investigate the interaction of the derivatives with P-glycoprotein. Using single-cell gel electrophoresis (alkaline comet assay), we showed that the derivatives of ARTA induce DNA breakage and accordingly programmed cell death, which represents a promising strategy in cancer treatment. ARTA activated apoptosis in cancer cells by the iron-mediated generation of reactive oxygen species (ROS). In conclusion, ARTA derivatives may bear the potential to be further developed as anticancer drugs. Full article

The cytochrome P450 2A6 (CYP2A6) enzyme metabolizes several clinically relevant substrates, including nicotine—the primary psychoactive component in cigarette smoke. The gene that encodes the CYP2A6 enzyme is highly polymorphic, resulting in extensive interindividual variation in CYP2A6 enzyme activity and the rate of metabolism of nicotine and other CYP2A6 substrates including cotinine, tegafur, letrozole, efavirenz, valproic acid, pilocarpine, artemisinin, artesunate, SM-12502, caffeine, and tyrosol. CYP2A6 expression and activity are also impacted by non-genetic factors, including induction or inhibition by pharmacological, endogenous, and dietary substances, as well as age-related changes, or interactions with other hepatic enzymes, co-enzymes, and co-factors. As variation in CYP2A6 activity is associated with smoking behavior, smoking cessation, tobacco-related lung cancer risk, and with altered metabolism and resulting clinical responses for several therapeutics, CYP2A6 expression and enzyme activity is an important clinical consideration. This review will discuss sources of variation in CYP2A6 enzyme activity, with a focus on the impact of CYP2A6 genetic variation on metabolism of the CYP2A6 substrates. Full article

The artemisinin compounds, which are well-known for their potent therapeutic antimalarial activity, possess in vivo and in vitro antitumor effects. Although the anticancer effect of artemisinin compounds has been extensively reported, the precise mechanisms underlying its cytotoxicity remain under intensive study. In the present study, a high-throughput quantitative proteomics approach was applied to identify differentially expressed proteins of HCT116 colorectal cancer cell line with artesunate (ART) treatment. Through Ingenuity Pathway Analysis, we discovered that the top-ranked ART-regulated biological pathways are abrogation of fatty acid biosynthetic pathway and mitochondrial dysfunction. Subsequent assays showed that ART inhibits HCT116 cell proliferation through suppressing the fatty acid biosynthetic pathway and activating the mitochondrial apoptosis pathway. In addition, ART also regulates several proteins that are involved in NF-κB pathway, and our subsequent assays showed that ART suppresses the NF-κB pathway. These proteomic findings will contribute to improving our understanding of the underlying molecular mechanisms of ART for its therapeutic cytotoxic effect towards cancer cells. Full article

Sonodynamic therapy (SDT) kills tumor cells through the synergistic effects of ultrasound (US) and a sonosensitizer agent. 5-Aminolevulinic acid (5-ALA) has been used as a sonodynamic sensitizer for cancer treatment. However, studies have shown that 5-ALA-based SDT has limited efficacy against malignant tumors. In this study, we examined whether artesunate (ART) could enhance the cytotoxicity of 5-ALA-based SDT against mouse mammary tumor (EMT-6) cells in vitro. In the ART, ART + US, ART + 5-ALA, and ART + 5-ALA + US groups, the cell survival rate correlated with ART concentration, and decreased with increasing concentrations of ART. Morphologically, many apoptotic and necrotic cells were observed in the ART + 5-ALA + US group. The percentage of reactive oxygen species-positive cells in the ART + 5-ALA + US group was also significantly higher than that in the 5-ALA group (p = 0.0228), and the cell death induced by ART + 5-ALA + US could be inhibited by the antioxidant N-acetylcysteine. These results show that ART offers great potential in enhancing the efficacy of 5-ALA-based SDT for the treatment of cancer. However, these results are only based on in vitro studies, and further in vivo studies are required. Full article