The Potential of Secondary Metabolites from Plants as Drugs or Leads against Protozoan Neglected Diseases-Part III: In-Silico Molecular Docking Investigations

In vitro, in silico, and STD-NMR studies of flavonoids from Hypericum helianthemoides (Spach) Boiss. against Leishmania major pteridine reductase 1 (LmPTR1)

Apigenin (1) and 3I,8II-biapigenin (2), a dimer of apigenin, were isolated from the aerial parts of Hypericum helianthemoides (Spach) Boiss. (Hypericaceae family). This study aimed to evaluate the in vitro inhibitory effects of flavonoids 1 and 2 against Leishmania major pteridine reductase-1 (LmPTR1), an essential enzyme for the growth of Leishmania parasites and other trypanosomatid protozoa. The second objective was to understand the binding interactions and structural properties of LmPTR1 inhibition at the atomic level through extensive in silico analyses and Saturation-Transfer Difference (STD)-NMR studies. Anti-LmPTR1 results showed that the dimeric form (2) was active (IC50 of 34.65 μM), while the monomeric form (1) was inactive. Computational analyses yielded a grid score of -52.14 kcal/mol and a free energy binding score of -38.23 kcal/mol. A stable ligand-receptor complex at the LmPTR1 binding site was observed for 2. Moreover, several important binding residues in the catalytic triad (Y194 and K198) and the substrate loop (L226, S227, S229, V230, and M233) interacted with 2. The STD-NMR results corroborated the computational simulations, indicating that H-6I and H-6II of the conjugated ring system on the biapigenin structure showed the highest interaction with the LmPTR1 active site. MTT assay results for 2 against human normal fibroblast cells (BJ cells) exhibited no cytotoxicity at concentrations of 50 and 100 μM. Overall, 3I,8II-biapigenin (2) displayed promise as a candidate for in vivo studies and anti-leishmanial drug development. Further evaluation of the anti-leishmanial and anti-LmPTR1 activities of bioflavonoid 2, along with its analogues, is warranted.

Antiprotozoal Activity of Plants Used in the Management of Sleeping Sickness in Angola and Bioactivity-Guided Fractionation of Brasenia schreberi J.F.Gmel and Nymphaea lotus L. Active against T. b. rhodesiense

Folk medicine is widely used in Angola, even for human African trypanosomiasis (sleeping sickness) in spite of the fact that the reference treatment is available for free. Aiming to validate herbal remedies in use, we selected nine medicinal plants and assessed their antitrypanosomal activity. A total of 122 extracts were prepared using different plant parts and solvents. A total of 15 extracts from seven different plants exhibited in vitro activity (>70% at 20 µg/mL) against Trypanosoma brucei rhodesiense bloodstream forms. The dichloromethane extract of Nymphaea lotus (leaves and leaflets) and the ethanolic extract of Brasenia schreberi (leaves) had IC50 values ≤ 10 µg/mL. These two aquatic plants are of particular interest. They are being co-applied in the form of a decoction of leaves because they are considered by local healers as male and female of the same species, the ethnotaxon "longa dia simbi". Bioassay-guided fractionation led to the identification of eight active molecules: gallic acid (IC50 0.5 µg/mL), methyl gallate (IC50 1.1 µg/mL), 2,3,4,6-tetragalloyl-glucopyranoside, ethyl gallate (IC50 0.5 µg/mL), 1,2,3,4,6-pentagalloyl-β-glucopyranoside (IC50 20 µg/mL), gossypetin-7-O-β-glucopyranoside (IC50 5.5 µg/mL), and hypolaetin-7-O-glucoside (IC50 5.7 µg/mL) in B. schreberi, and 5-[(8Z,11Z,14Z)-heptadeca-8,11,14-trienyl] resorcinol (IC50 5.3 µg/mL) not described to date in N. lotus. Five of these active constituents were detected in the traditional preparation. This work provides the first evidence for the ethnomedicinal use of these plants in the management of sleeping sickness in Angola.

Characterization and anticancer potential of Withania somnifera fruit bioactives (a native species to Pakistan) using gas chromatography-mass spectrometer, nuclear magnetic resonance and liquid chromatography-mass spectrometry-electrospray ionization

INTRODUCTION

Withania somnifera (W. somnifera) is a plant with remarkable pharmacological properties. The plant has an impressive profile of medicinal uses in the folk medicine system of several civilizations.

AIM

This comprehensive study is aimed to characterize phytochemicals in fruit of W. somnifera and tested for anticancer potential to find out active candidate in disease prevention and treatment.

METHODS

The bioactive components from W. somn-ifera fruit were extracted with polar and non-polar solvents. Anticancer potential of the isolated bioactive was assessed against different cancer cell lines through MTT assay and Incucytes imaging analysis. The extracts were characterized for secondary metabolites using GC-MS (gas chromatography-mass spectrometer), LCMS (liquid chromatography-mass spectrometry)-ESI (electrospray Ionization) and 1H-NMR (electrospray Ionization) techniques.

RESULTS

Both freeze-dried and rotary evaporator con-densed extracts exhibited anticancer potential against MDA-MB-231, MCF7- SKOV3 and SKBR3 cell lines. The tested extracts have cell growth inhibition potential ag-ainst mammalian cancer cell line. Hexacosanedioic acid purified from -hexane extract through HPLC was inves-tigated for its cytotoxicity against breast cancer cell line SKBR3 by using Incucytes imaging analysis.

CONCLUSION

We found that a variety of bioactive compounds existed in this plant. One identified compound that was not investigated for cytotoxicity in previous studies was purified and its application showed cytotoxicity on breast cancer cell lines. A number of bioactive identified from fruit may have an effective potential for development into chemotherapy drugs.

Chemical Composition and In Vitro and In Silico Antileishmanial Evaluation of the Essential Oil from Croton linearis Jacq. Stems

Croton linearis Jacq. is an aromatic shrub that has been utilized in traditional medicine in the Bahamas, Jamaica, and Cuba. Recent studies have revealed the antiprotozoal potential of its leaves. The present work is aimed to identify the volatile constituents of essential oil from the stems of C. linearis (CLS-EO) and evaluate its in vitro antileishmanial activity. In addition, an in silico study of the molecular interactions was performed using molecular docking. A gas chromatographic-mass spectrometric analysis of CLS-EO identified 1,8-cineole (27.8%), α-pinene (11.1%), cis-sabinene (8.1%), p-cymene (5.7%), α-terpineol (4.4%), epi-γ-eudesmol (4.2%), linalool (3.9%), and terpinen-4-ol (2.6%) as major constituents. The evaluation of antileishmanial activity showed that CLS-EO has good activity on both parasite forms (IC_{50Promastigote} = 21.4 ± 0.1 μg/mL; IC_50Amastigote = 18.9 ± 0.3 μg/mL), with a CC₅₀ of 49.0 ± 5.0 μg/mL on peritoneal macrophages from BALB/c mice (selectivity index = 2 and 3 using the promastigote and amastigote results). Molecular docking showed good binding of epi-γ-eudesmol with different target enzymes of Leishmania. This study is the first report of the chemical composition and anti-Leishmania evaluation of CLS-EO. These findings provide support for further studies of the antileishmanial effect of this product.

In Vitro Antimalarial Activity and Phytochemical Analysis of Aerial Parts of Artemisia fragrans Willd

Background: Malaria is one of the most momentous transmittable diseases globally. Medicinal herbs like Artemisia species might be possible sources of new, effective, and cheap antiplasmodial products, making up the leading molecules to investigate new antimalarial drugs. The Artemisia genus, which belongs to the Asteraceae family, is a widely distributed medicinal plant in Iran. Methods: In this study, the antimalarial activities of essential oil, different extracts, and vacuum liquid chromatography (VLC) fractions of A. fragrans Willd. were examined by a cell-free β-hematin formation assay. The aerial parts of A. fragrans were extracted by a Soxhlet extractor, and essential oil was obtained by a Clevenger apparatus. Then, GC-MS analysis was used to identify volatile compounds of essential oil and the 100% VLC fraction of chloroform. Results: Among the extracts, chloroform extract illustrated considerable antimalarial activity compared to the control (P < 0.001), with the IC50 value of 1.22 ± 0.05 mg/mL. Among the fractions, 100% VLC fraction of chloroform extract illustrated potent antimalarial effects compared to the control (P < 0.001). The volatile oil demonstrated moderate antimalarial effects (P < 0.001) compared with the control. Besides, GC-MS determined that sesquiterpenes in the 100% ethyl acetate fraction of the chloroform extract and oxygenated monoterpenes in the essential oil might be responsible for the potent antimalarial activity of this plant. Conclusions: The 100% ethyl acetate fraction of chloroform extract along with the essential oil of A. fragrance indicated potent and moderate activity, possibly due to sesquiterpenes and oxygenated monoterpenes, respectively.

Balanced QSAR and Molecular Modeling to Identify Structural Requirements of Imidazopyridine Analogues as Anti-infective Agents Against Trypanosomiases

Human African trypanosomiasis (HAT), a fatal infection caused by Trypanosoma brucei (T. brucei) is considered as a neglected disease in the tropical areas, and newer agents with unique mechanism of action are urgently needed. In this work, 65 Imidazopyridine analogues from known literature were selected for building statistically robust genetic algorithm (GA) based QSAR models. Furthermore, values for the various cross-validation properties supported its statistical robustness (model 1, [Formula: see text], RMSE[Formula: see text], MAE[Formula: see text], CCC[Formula: see text], and [Formula: see text]). Our in silico ADMET analysis revealed that a designed molecule, S10 may act as potent lead (T. brucei, pEC[Formula: see text] ([Formula: see text]M), [Formula: see text]) with better pharmacokinetics, no carcinogenicity, class III acute oral toxicity, minimal OCT1 and OCT2 inhibitions and no eye corrosion profiles. Our molecular docking analysis (on 42 drug targets) for a dataset and designed molecules demonstrated higher binding affinity of Imidazopyridine analogues with T. brucei farnesyl diphosphate synthase (TbFPPS) (PDB id: 2I19). This observation was further supported by 100[Formula: see text]ns molecular dynamics analysis retaining better stability of complex. Thus, imidazopyridine analogues would provide a promising scaffold for the development of anti-HAT agents.

Antileishmanial Potential of Berberine Alkaloids From Berberis glaucocarpa Roots: Molecular Docking Suggests Relevant Leishmania Protein Targets

Leishmaniases are a spectrum of poverty-linked neglected parasitic diseases that are endemic in 88 countries around the globe and affect millions of people every year. Currently available chemotherapeutic options are inadequate due to side effects, high cost, prolonged treatment, and parasite resistance. Thus, there is an existing need to develop new potent and safer leishmanicidal drugs. Considering the folkloric antiulcer and leishmanicidal use of the genus Berberis and its alkaloids, 5 reported alkaloids, namely berberine (1), palmatine (2), columbamine (3), 8-trichloromethyldihydroberberine (4), and jatrorrhizine (5), were isolated from the roots of Berberis glaucocarpa using classical (column and preparative chromatography) and modern isolation techniques (Sephadex LH-20). Their structures were elucidated and established from 1D and 2D spectroscopic data. The isolated alkaloids displayed excellent antileishmanial potential with IC50 values ranging from 1.50 to 2.56 µM: 1 (1.50 ± 0.53 µM), 2 (2.31 ± 0.37 µM), 3 (2.56 ± 0.48 µM), 4 (1.40 ± 0.90 µM), 5 (2.44 ± 1.34 µM). While the IC50 value for the standard drug (Amphotericin-B) was found to be 1.08 ± 0.95 µM. All of the isolated alkaloids displayed excellent antileishmanial potential as well as minimal cytotoxicity against THP-1 monocytic cells. Molecular docking analysis has revealed Leishmania N-myristoyl transferase, methionyl-tRNA synthetase, pteridine reductase 1, oligopeptidase B, tyrosyl-tRNA synthetase, and/or glycerol-3-phosphate dehydrogenase to be potential protein targets for the alkaloids.

Antitrypanosomal Lactones from Nectandra barbellata

Twigs of Nectandra barbellata were extracted using a solution of the ionic liquid 1-butyl-3-methylimidazolium bromide (BMImBr) in H₂O, assisted by microwave (MAE). After successive chromatographic steps, one sesquiterpene, costic acid, and three new related lactones, (R)-3(7)-Z-3-hexadec-21-enylidene-5-(hydroxymethyl)tetrahydrofuran-2-one (1), (R)-3(7)-Z-3-hexadecylidene-5-(hydroxymethyl)tetrahydrofuran-2-one (2), and (R)-3(7)-Z-3-docosylidene-5-(hydroxymethyl)tetrahydrofuran-2-one (3), were isolated. After structural elucidation using IR, UV, HRESIMS, NMR, ECD, and VCD, compounds 1-3 were tested against trypomastigote forms of Trypanosoma cruzi. The mechanism of action of bioactive isolated compounds was studied using different fluorescent-based approaches to investigate alterations of the plasma membrane, permeability/electric potential (ΔΨ_p), reactive oxygen species levels, mitochondria (electric membrane potential, ΔΨ_m/ATP levels), Ca²⁺ levels, and pH of the acidocalcisomes. In addition, in silico studies predicted no resemblance to pan assay interference compounds (PAINS).

A Novel Series of [1,2,4]Triazolo[4,3-a]Pyridine Sulfonamides as Potential Antimalarial Agents: In Silico Studies, Synthesis and In Vitro Evaluation

For the development of new and potent antimalarial drugs, we designed the virtual library with three points of randomization of novel [1,2,4]triazolo[4,3-a]pyridines bearing a sulfonamide fragment. The library of 1561 compounds has been investigated by both virtual screening and molecular docking methods using falcipain-2 as a target enzyme. 25 chosen hits were synthesized and evaluated for their antimalarial activity in vitro against Plasmodium falciparum. 3-Ethyl-N-(3-fluorobenzyl)-N-(4-methoxyphenyl)-[1,2,4]triazolo[4,3-a]pyridine-6-sulfonamide and 2-(3-chlorobenzyl)-8-(piperidin-1-ylsulfonyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one showed in vitro good antimalarial activity with inhibitory concentration IC₅₀ = 2.24 and 4.98 μM, respectively. This new series of compounds may serve as a starting point for future antimalarial drug discovery programs.

Use of herbal remedies in the management of sleeping sickness in four northern provinces of Angola

ETHNOPHARMACOLOGICAL RELEVANCE

This study reports for the first time on the use of folk medicine to treat sleeping sickness and its symptoms in four endemic provinces in northern Angola. By interviewing both traditional practitioners and confirmed patients, it highlights reasons to recourse to folk medicine, the plant species used for this affection as well as arises awareness about the use of particular plants showing potential risks.

AIM OF THE STUDY

The aims of this explorative study were three-fold. Firstly, it informed on access to, and use of plant-based medicine as first-choice treatment by infected persons. Secondly, it aimed at collecting comprehensive data from patients and traditional healers on herbal remedies in order to identify plant species used in the management of the disease. Thirdly, it served as contribution for primary indication of potential risk of use associated with the studied plants and their preparation.

MATERIALS AND METHODS

The study was conducted in 4 endemic provinces of Angola, namely Bengo, Zaire, Kwanza Norte and Uíge. We explored the use of herbal remedies by conducting structured and semi-structured interviews within two distinct study populations. The first group comprises 30 patients who had been diagnosed for trypanosomiasis and treated by the reference treatment. The second group included 9 traditional practitioners who had already treated sleeping sickness. The plants that were cited during the interviews were collected during field walks under supervision of a traditional healer, then authenticated and deposited at the National Herbarium in Luanda.

RESULTS

Of the 30 included patients, 12 (40%) had turned to folk medicine in the management of trypanosomiasis and related symptoms. 7 medicinal plants were reported by this group. Considering the key motivation to consult a traditional practitioner, two main factors accounted for half of the cases: "past experience with folk medicine" and "family habit". Out of 9 traditional practitioners' interviewees, 26 medicinal plants were cited. Roots and leaves were the most used plant parts, and decoction was the common mode of preparation. Evidence for antitrypanosomal activity in the scientific literature was found for 56% (17 of 30) of the identified plant species. The most cited plant was Crossopteryx febrifuga (UR = 6). Some of the cited plants, as for example Aristolochia gigantea, raised concern about potential toxicity.

CONCLUSIONS

With 40% of infected persons having turned first to folk medicine before consulting a medical doctor, this explorative study points out that plant-based medicines play an important role in local dynamics of health care. It highlights the need for primary assessment of potential risk of use related to the herbal recipes, and for reporting it to the concerned population. This first ethnobotanical study on trypanosomiasis in endemic provinces of Angola provides information on 30 plants, of which some had been identified as promising for further pharmacological research. Our results provide a first step towards the validation and valorization of Angolan herbal remedies for sleeping sickness.

Effect of Temperature on 1H NMR Spectra, Antitrypanosomal Activity, Conformational Analysis, and Molecular Docking of Curine Derivatives from Berberis brevissima

The ethanolic root extract of Berberis brevissima afforded a new bisbenzylisoquinoline alkaloid, 13-nitrochondrofoline (2), and two known bisbenzylisoquinoline alkaloids, chondrofoline (1) and curine (4). The acetylation of chondrofoline (1) gave O-acetylchondrofoline (3). The dimeric structures of 1 and 2 were studied through variable-temperature ¹H NMR spectroscopy at 25, 40, 60, and 80 °C and conformational analysis, using density functional theory employing the M06-2X functional and the 6-31G* basis set. The in vitro antitrypanosomal activity of compounds 1, 2, 3, and 4 against Trypanosoma brucei showed significant potential with MIC values of 2.6, 2.2, 2.3, and 3.8 μM, respectively. Molecular docking evaluation of alkaloids 1, 2, 3, and 4 against known T. brucei protein targets revealed T. brucei phosphodiesterase B1 to be the preferred target. The docking energies of the alkaloids with Tb6PGL (PDB 3EB9) ranged from -88.8 to -106.0 kJ/mol and was comparable to the cocrystallized ligand, citrate (E_dock = -78.3 kJ/mol). It seems reasonable that the curine alkaloids may compete with the natural substrates for these protein targets and serve as leads in designing and developing more potent and selective drugs against T. brucei.

Novel method for improving ardicrenin content in hairy roots of Ardisia crenata Sims plants

To develop an alternative medicine related with taxol/camptothecin, a hairy roots induction system for measuring triterpenoid saponin ardicrenin was established. In the current study, mature and healthy seeds of Ardisia crenata plants were selected for obtaining aseptic seedlings. Two Agrobacterium rhizogenes strains ATCC 15834 and A4 were used to infect aseptic euphylla for inducing hairy roots of A. crenata plants. For the best combination of seeds germination, a Murashige-Skoog medium containing 1.0 mg L^-1 6-benzylaminopurine and 1.0 mg L^-1 naphthalene acetic acid was made, which reached a rate of 92.4 %. Results showed that ATCC 15834 and A4 both induced hairy roots of A. crenata for improving ardicrenin production. The PCR analysis demonstrated that ATCC 15834 and A4 Ri plasmid T-DNA had been successfully transferred and integrated into the genome of leaf cell nuclei, however the Vir region was not. Further, ardicrenin content in hairy roots ACHR 15834 8.2 %) induced by ATCC 15834 was quantified by the RP-HPLC, which was also 1.8-, 2.7-, 9.4- and 2.6-fold greater than those of ACHR 4 induced by A4 (4.5 %), ACR C formed by tissue culture (3.1 %), euphylla (0.8 %) and NR C formed nature (3.2 %), respectively. Taken together, hairy root lines of A. crenata obtained were able to express naturally more ardicrenin than natural plants.

Repositioning of HIV Aspartyl Peptidase Inhibitors for Combating the Neglected Human Pathogen Trypanosoma cruzi

Chagas disease, caused by the flagellate parasite Trypanosoma cruzi, is a wellknown neglected tropical disease. This parasitic illness affects 6-7 million people and can lead to severe myocarditis and/or complications of the digestive tract. The changes in its epidemiology facilitate co-infection with the Human Immunodeficiency Virus (HIV), making even more difficult the diagnosis and prognosis. The parasitic infection is reactivated in T. cruzi/HIV co-infection, with the appearance of unusual manifestations in the chronic phase and the exacerbation of classical clinical signs. The therapeutic arsenal to treat Chagas disease, in all its clinical forms, is restricted basically to two drugs, benznidazole and nifurtimox. Both drugs are extremely toxic and the therapeutic efficacy is still unclear, making the clinical treatment a huge issue to be solved. Therefore, it seems obvious the necessity of new tangible approaches to combat this illness. In this sense, the repositioning of approved drugs appears as an interesting and viable strategy. The discovery of Human Immunodeficiency Virus Aspartyl Peptidase Inhibitors (HIV-PIs) represented a milestone in the treatment of Acquired Immune Deficiency Syndrome (AIDS) and, concomitantly, a marked reduction in both the incidence and prevalence of important bacterial, fungal and parasitic co-infections was clearly observed. Taking all these findings into consideration, the present review summarizes the promising and beneficial data concerning the effects of HIV-PIs on all the evolutionary forms of T. cruzi and in important steps of the parasite's life cycle, which highlight their possible application as alternative drugs to treat Chagas disease.

Continuous Evaluation of Ligand Protein Predictions: A Weekly Community Challenge for Drug Docking

Docking calculations can accelerate drug discovery by predicting the bound poses of ligands for a targeted protein. However, it is not clear which docking methods work best. Furthermore, predicting poses requires steps outside the docking algorithm itself, such as preparation of the protein and ligand, and it is not known which components are most in need of improvement. The Continuous Evaluation of Ligand Protein Predictions (CELPP) is a blinded prediction challenge designed to address these issues. Participants create a workflow to predict protein-ligand binding poses, which is then tasked with predicting 10-100 new protein-ligand crystal structures each week. CELPP evaluates the accuracy of each workflow's predictions and posts the scores online. The results can be used to identify the strengths and weaknesses of current approaches, help map docking problems to the algorithms most likely to overcome them, and illuminate areas of unmet need in structure-guided drug design.

Untargeted LC-MS metabolomic studies of Asteraceae species to discover inhibitors of Leishmania major dihydroorotate dehydrogenase

INTRODUCTION

Interesting data about the family Asteraceae as a new source of Leishmania major dihydroorotate dehydrogenase (LmDHODH) inhibitors are presented. This key macromolecular target for parasites causing neglected diseases catalyzes the fourth reaction of the de novo pyrimidine biosynthetic pathway, which takes part in major cell functions, including DNA and RNA biosynthesis.

OBJECTIVES

We aimed to (1) determine LmDHODH inhibitor candidates, revealing the type of chemistry underlying such bioactivity, and (2) predict the inhibitory potential of extracts from new untested plant species, classifying them as active or inactive based on their LC-MS based metabolic fingerprints.

METHODS

Extracts from 150 species were screened for the inhibition of LmDHODH, and untargeted UHPLC-(ESI)-HRMS metabolomic studies were carried out in combination with in silico approaches.

RESULTS

The IC₅₀ values determined for a subset of 59 species ranged from 148 µg mL^-1 to 9.4 mg mL^-1. Dereplication of the metabolic fingerprints allowed the identification of 48 metabolites. A reliable OPLS-DA model (R² > 0.9, Q² > 0.7, RMSE_CV < 0.3) indicated the inhibitor candidates; nine of these metabolites were identified using data from isolated chemical standards, one of which-4,5-di-O-E-caffeoylquinic acid (IC₅₀ 73 µM)-was capable of inhibiting LmDHODH. The predictive OPLS model was also effective, with 60% correct predictions for the test set.

CONCLUSION

Our approach was validated for (1) the discovery of LmDHODH inhibitors or interesting starting points for the optimization of new leishmanicides from Asteraceae species and (2) the prediction of extracts from untested species, classifying them as active or inactive.

Copaifera of the Neotropics: A Review of the Phytochemistry and Pharmacology

The oleoresin of Copaifera trees has been widely used as a traditional medicine in Neotropical regions for thousands of years and remains a popular treatment for a variety of ailments. The copaiba resins are generally composed of a volatile oil made up largely of sesquiterpene hydrocarbons, such as β-caryophyllene, α-copaene, β-elemene, α-humulene, and germacrene D. In addition, the oleoresin is also made up of several biologically active diterpene acids, including copalic acid, kaurenoic acid, alepterolic acid, and polyalthic acid. This review presents a summary of the ecology and distribution of Copaifera species, the traditional uses, the biological activities, and the phytochemistry of copaiba oleoresins. In addition, several biomolecular targets relevant to the bioactivities have been implicated by molecular docking methods.

Antioxidant and Anti-Inflammatory Properties of Anacardium occidentale Leaf Extract

In tropical America, principally in Northeastern Brazil, the leaf extract of Anacardium occidentale is traditionally used for treatment of different diseases. However, chemical and biological properties and activities of Anacardium occidentale are poorly investigated and known. Here, we evaluated the antioxidant and anti-inflammatory activities “in vitro” of leaf extract from Anacardium occidentale. Our results show that leaf extract exhibits antioxidant activity when used to treat RAW 264.7 macrophage cells. Antioxidant effects were observed by decrease in oxidative damage in macrophage cells treated with 0.5 µg/mL and 5 µg/mL of leaf extract. Moreover, leaf extract reversed oxidative damage and inflammatory parameters induced in LPS-stimulated RAW 264.7 macrophage cells. Leaf extract at 0.5 µg/mL and 5 µg/mL was able to inhibit release of TNF-α and IL-1β in LPS-stimulated cells. Taken together, our results indicate antioxidant and anti-inflammatory effects of leaf extract from Anacardium occidentale and reveal the positive effects that intake of these products can mediate in biological system.

Natural Products as New Treatment Options for Trichomoniasis: A Molecular Docking Investigation

Trichomoniasis, caused by the parasitic protozoan Trichomonas vaginalis, is the most common non-viral sexually-transmitted disease, and there can be severe complications from trichomoniasis. Antibiotic resistance in T. vaginalis is increasing, but there are currently no alternatives treatment options. There is a need to discover and develop new chemotherapeutic alternatives. Plant-derived natural products have long served as sources for new medicinal agents, as well as new leads for drug discovery and development. In this work, we have carried out an in silico screening of 952 antiprotozoal phytochemicals with specific protein drug targets of T. vaginalis. A total of 42 compounds showed remarkable docking properties to T. vaginalis methionine gamma-lyase (TvMGL) and to T. vaginalis purine nucleoside phosphorylase (TvPNP). The most promising ligands were polyphenolic compounds, and several of these showed docking properties superior to either co-crystallized ligands or synthetic enzyme inhibitors.