Computational studies on new Leishmanial drug targets against Quercetin

Leishmaniasis, a parasitic disease caused by Leishmania parasite which resides in the infected sand flies. Control of Leishmaniasis remains a source of grave concern worldwide. Studies on Leishmaniasis triggered because of its outbreak in tropical and subtropical regions of Asia, East Africa and South America. There is an urgent need for new therapeutic interventions such as vaccine and new drug targets as it develops resistance towards the available drugs. Quercetin, a derivative of polyphenolic flavonoid exhibits various biological activities by interacting with proteins and nucleic acids. In this study, computational analysis was performed to identify the potential drug target of Quercetin in Leishmania species by molecular docking. The newly predicted targets were subjected for subcellular localization prediction and determined the protein-protein interaction networks that would aid in the development of anti-Leishmanial drugs. This study helps in the identification of targets and development of anti-Leishmanial drugs.

Atividade antileishmanial dos óleos essenciais: uma revisão

Introdução: a leishmaniose, uma doença negligenciada que afeta mais de 200 países, apresenta algumas limitações em seu tratamento, como a possibilidade de efeitos colaterais graves, promovidos pelos medicamentos e o desenvolvimento de variedades de Leishmania com resistência a medicamentação. Visto os problemas apresentados pelos tratamentos atuais, novos medicamentos têm sido pesquisados, dentre eles, os óleos essenciais, que são apontados como um dos mais promissores, pois além de ter origem natural, apresentam bom potencial inibitório e podem estimular o sistema de defesa do organismo contra a Leishmania. Objetivo: abordar a atividade antileishmanial dos óleos essenciais, mais especificamente o potencial inibitório e sua seletividade. Os mecanismos de ação já reportados também são comentados. Resultados: o potencial inibitório dos óleos essenciais (OE) contra a Leishmania é influenciado principalmente pela presença de hidroxila aromática nos componentes isolados os OE, pela forma evolutiva e pela espécie de Leishmania. A seletividade apresenta pelos OE é influenciada pela composição química e pela forma evolutiva da Leishmania. Os principais mecanismos de ação dos OE são a apoptose mitocondrial da Leishmania e, quando na forma amastigota, a estimulação do sistema imune do macrófago infectado. Conclusão: os OE apresentam potencial para aplicação como medicamentos contra a Leishmania, todavia, é necessário considerar a presença de hidroxilas aromáticas em sua composição para melhor aplicabilidade.

SUMMARY Introduction: Leishmaniasis, a neglected disease that affects over 200 countries, has some limitations in its treatment, the main ones being the possibility of severe collecting effects promoted by medicines and the development of Leishmania varieties with resistance to medication. Considering the problems presented by the current treatments, new medicines have been researched, among them, the essential oils are pointed out as one of the most promising, because besides having natural origin, have good inhibitory potential and can stimulate the organism's defense system against Leishmania. Aim: To review addresses the antileishmanial activity of essential oils, more specifically the inhibitory potential and its selectivity. The action mechanisms already reported are also commented. Results: The inhibitory potential of essential oils (OE) against Leishmania is influenced mainly by the presence of aromatic hydroxyl in the OE isolated components, by the evolutionary form and by the species of Leishmania. The selectivity presented by the OE is influenced by the chemical composition and the evolutionary form of Leishmania. The main mechanisms of action of OE are mitochondrial apoptosis of Leishmania and, when in amastigote form, stimulation of the immune system of infected macrophage. Conclusion: The OE have the potential to be applied as drugs against Leishmania, however, it is necessary to consider the presence of aromatic hydroxyls in their composition for better applicability.

Introducción: la leishmaniosis, una enfermedad desatendida que afecta a más de 200 países, tiene algunas limitaciones en su tratamiento. Entre estos, la posibilidad de efectos secundarios graves, promovidos por fármacos y el desarrollo de variedades de Leishmania con resistencia a la medicación. Dado que existen problemas que presentan los tratamientos actuales, se han investigado nuevos fármacos, entre ellos, los aceites esenciales, los cuales se señalan como uno de los más prometedores, pues además de tener un origen natural, tienen un buen potencial inhibitorio y pueden estimular el sistema de defensa contra Leishmania. Objetivo: abordar la actividad antileishmanial de los aceites esenciales, más específicamente el potencial inhibitorio y su selectividad. También se comentan los mecanismos de acción ya reportados. Resultados: el potencial inhibitorio de los aceites esenciales (OE) contra la Leishmania está influenciado principalmente por la presencia de hidroxilo aromático en los componentes aislados de los OE, por la forma evolutiva y por la especie de Leishmania. La selectividad presenta por los OE es influenciada por la composición química y por la forma evolutiva de la Leishmania. Los principales mecanismos de acción de los OE son la apoptosis mitocondrial de la Leishmania y, cuando en forma amastigota, la estimulación del sistema inmune del macrófago infectado. Conclusión: los OE presentan potencial para aplicación como medicamentos contra la Leishmania, sin embargo, es necesario considerar la presencia de hidroxilas aromáticas en su composición para mejor aplicabilidad.

Ficus carica hairy roots: In vitro anti-leishmanial activity against Leishmania major promastigotes and amastigotes

Objective: To investigate the biochemical capacity, and in vitro inhibitory effects of hairy roots from two cultivars of Ficus carica L. (Sabz and Siah) on Leishmania major promastigotes and amastigotes. Methods: In the hairy roots, the activity of antioxidant enzymes compared to normal leaves and roots, and the presence of some phenolic compounds in comparison with fruits were investigated. The IC 50 values of hairy roots in promastigotes was determined by tetrazolium-dye 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and trypan blue assays. By calculating the infectivity index of peripheral blood mononuclear cells (PBMCs), the leishmanicidal activity (IC 50 values) of hairy roots for amastigotes was estimated. The effects of hairy roots (IC 50 values) treatment on the levels of IFN-γ and iNOS expression, intracellular reactive oxygen species, and iNOS protein expression in infected-PBMCs were determined. Results: Based on antioxidant enzyme assays and high performance liquid chromatography analysis, hairy roots exhibited high antioxidant capacity and contained high levels of phenolic compounds. According to the results of tetrazolium-dye 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and trypan blue assays, the hairy root extracts of both cultivars showed considerable dose-dependent inhibitory effects against Leishmania major promastigotes. Depending on the concentration and exposure time, treatment of infected-PBMCs with hairy root extracts caused the generation of a significant reactive oxygen species, up-regulation of IFN-γ and iNOS genes expression, and high value of iNOS protein compared to controls. Conclusions: The findings of this study suggest that the hairy roots of Ficus carica can be considered as a promising natural source of antileishmanial agents.

Antileishmanial metallodrugs and the elucidation of new drug targets linked to post-translational modifications machinery: pitfalls and progress

Despite the increasing number of manuscripts describing potential alternative antileishmanial compounds, little is advancing on translating these knowledges to new products to treat leishmaniasis. This is in part due to the lack of standardisations during pre-clinical drug discovery stage and also depends on the alignment of goals among universities/research centers, government and pharmaceutical industry. Inspired or not by drug repurposing, metal-based antileishmanial drugs represent a class that deserves more attention on its use for leishmaniasis chemotherapy. Together with new chemical entities, progresses have been made on the knowledge of parasite-specific drug targets specially after using CRISPR/Cas system for functional studies. In this regard, Leishmania parasites undergoe post-translational modification as key regulators in several cellular processes, which represents an entire new field for drug target elucidation, once this is poorly explored. This perspective review describes the advances on antileishmanial metallodrugs and the elucidation of drug targets based on post-translational modifications, highlighting the limitations on the drug discovery/development process and suggesting standardisations focused on products addressed to who need it most.

In vitro and in vivo activity of a hypotoxic copper(I) complex against dermotropic Leishmania species / Atividade in vitro e in vivo de um complexo de cobre(I) hipotóxico contra espécies dermotrópicas de Leishmania

Cutaneous leishmaniasis is a disease caused by protozoa of the genus Leishmania and, currently, the treatment of first choice is meglumine antimoniate. However, due to its limited effectiveness and high toxicity, it is necessary to seek new active principles for leishmaniasis treatment. Metal complexes are gaining importance due to their effectiveness and low toxicity. In this context, the present study aimed to evaluate the in vitro and in vivo antileishmanial activity of the hypotoxic copper(I) complex [HB(pz)3]Cu(PCN). Four dermotropic species of Leishmania were tested with the metal complex and its effectiveness was determined through parasitic viability and infectivity rate, and cytotoxicity was determined using a redox dye (resazurin). For the in vivo tests, hamsters were infected and the lesions treated with a formulated ointment containing the complex, the effectiveness of which was assessed by measuring the diameter of the inoculum/snout location and determining the parasitic load. The results demonstrated moderate toxicity in murine macrophages and human monocytes and better efficacy in Leishmania (V.) braziliensis when compared to the other species tested, with a 50% reduction in the viability of promastigote and amastigote forms (in vitro). General data from daily topical treatment for up to 30 days showed low efficacy for reducing lesions, and no clinical and parasitological cure was observed in the experimental animals. Thus, the [HB(pz)3]Cu(PCN) complex proved to be promising in in vitro studies against L. (V.) braziliensis, and should be further tested in new formulations and new experimental treatment schemes.

A leishmaniose cutânea é uma doença causada por protozoários do gênero Leishmania e, atualmente, o tratamento de primeira escolha é o antimoniato de meglumina. Porém, devido à sua eficácia limitada e alta toxicidade, é necessário buscar novos princípios ativos para o tratamento da leishmaniose. Os complexos metálicos vêm ganhando importância devido à sua eficácia e baixa toxicidade. Nesse contexto, o presente estudo teve como objetivo avaliar a atividade leishmanicida in vitro e in vivo do complexo hipotóxico de cobre(I) [HB(pz)3]Cu(PCN). Quatro espécies dermotrópicas de Leishmania foram testadas com o complexo metálico e sua eficácia foi determinada através da viabilidade parasitária e taxa de infectividade, e a citotoxicidade foi determinada com um corante redox (resazurina). Para os testes in vivo, hamsters foram infectados e as lesões foram tratadas com uma pomada formulada contendo o complexo. A eficácia foi avaliada medindo o diâmetro do inóculo/focinho e determinando a carga parasitária. Os resultados demonstraram toxicidade moderada em macrófagos murinos e monócitos humanos e melhor eficácia em Leishmania (V.) braziliensis quando comparada às demais espécies testadas, com redução de 50% na viabilidade das formas promastigotas e amastigotas (in vitro). Os dados gerais do tratamento tópico diário por até 30 dias mostraram baixa eficácia na redução das lesões, e nenhuma cura clínica e parasitológica foi observada nos animais experimentais. Portanto, o complexo [HB(pz)3]Cu(PCN) mostrou-se promissor em estudos in vitro contra L. (V.) braziliensis, devendo ser empregado em novas formulações e novos esquemas de tratamento experimental.

Effect of Vigna radiata, Tamarix ramosissima and Carthamus lanatus extracts on Leishmania major and Leishmania tropica: An in vitro study / 中草药·英文版

Objective: Current therapy strategies of leishmaniasis have some problems such as high cost, toxicity and side effects. Plant extracts can be a source of drugs to control leishmaniasis. In this study, the effect of hydroalcoholic and chloroformic extracts of Vigna radiata, Tamarix ramosissima, and Carthamus lanatus on Leishmania major and L. tropica was studied. Methods: The plant samples were collected from west of Iran and their extracts were prepared. Anti-promastigote activity assay of all extracts was done using tetrazolium-dye assay. Results: Only high concentrations of V. radiata and C. lanatus were able to inhibit Leishmania, while both high and low concentrations of T. ramosissima had antileishmanial effect. No difference was observed between hydroalcoholic with chloroformic extract of each plant. Conclusion: Altogether, the results revealed the antileishmanial activity of T. ramosissima extracts against L. major and L. tropica, indicating its potential as an antileishmanial agent.

Antileishmanial activity and immunomodulatory effect of secosubamolide, a butanolide isolated from Nectandra oppositifolia (Lauraceae)

Visceral leishmaniasis is a complex neglected tropical disease caused by Leishmania donovani complex. Its current treatment reveals strong limitations, especially high toxicity. In this context, natural products are important sources of new drug alternatives for VL therapy. Therefore, the antileishmanial and immunomodulatory activity of compounds isolated from Nectandra oppositifolia (Lauraceae) was investigated herein. Methods: The n-hexane extract from twigs of N. oppositifolia were subjected to HPLC/HRESIMS and bioactivity-guided fractionation to afford compounds 1 and 2 which were evaluated in vitro against Leishmania (L.) infantum chagasi and NCTC cells. Results: The n-hexane extract displayed activity against L. (L.) infantum chagasi and afforded isolinderanolide E (1) and secosubamolide A (2), which were effective against L. (L.) infantum chagasi promastigotes, with IC50 values of 57.9 and 24.9 µM, respectively. Compound 2 was effective against amastigotes (IC50 = 10.5 µM) and displayed moderate mammalian cytotoxicity (CC50 = 42 µM). The immunomodulatory studies of compound 2 suggested an anti-inflammatory activity, with suppression of IL-6, IL-10, TNF with lack of nitric oxide. Conclusion: This study showed the antileishmanial activity of compounds 1 and 2 isolated from N. oppositifolia. Furthermore, compound 2 demonstrated an antileishmanial activity towards amastigotes associated to an immunomodulatory effect.(AU)

Antileishmanial in vitro activity of essential oil from Myrciaria plinioides, a native species from Southern Brazil

In South American folk medicine members of the genus Myrciaria are used for the treatment of malaria, diarrhoea, asthma, inflammation and post-partum uterine cleansing. The aim of this work was to evaluate its antileishmanial properties (in vitro) of essential oil derived from leaves of Myrciaria plinioides D. Legrand, a plant species that is native in South of Brazil. The essential oil was obtained by hydro-distillation using fresh leaves of M. plinioides. The chemical composition of this essential oil (MPEO, M. plinioides essential oil) was determined by gas chromatography coupled to mass spectrometry (GC-MS). MPEO was assayed in vitro for antileishmanial properties against promastigotes of Leishmania amazonensis and Leishmania infantum, and for cytotoxicity against murine peritoneal macrophages. The MPEO comprised 66 components and was rich in oxygenated sesquiterpenes (82.66%) containing spathulenol (21.12%) as its major constituent. The MPEO was effective against L. amazonensis with IC50 value of 14.16 ± 7.40 µg/mL, while against L. infantum the IC50 value was higher with 101.50 ± 5.78 µg/mL. The MPEO showed significant activity against L. amazonensis, and presented a selectivity index (SI) of 6.60. The results suggest that the essential oil from leaves of M. plinioides is a promising source for new antileishmanial agents against L. amazonensis.

A Novel Niosomal Combination of Selenium Coupled with Glucantime against Leishmania tropica

There is no effective treatment modality available against different forms of leishmaniasis. Therefore, the aim of this study was to improve the penetration and efficacy of selenium and glucantime coupled with niosomes and compared them with their simple forms alone on in vitro susceptibility assays. In this study, the niosomal formulations of selenium and in combination with glucantime were prepared. The size and morphology of the niosomal formulations were characterized and the effectivity of the new formulation was also evaluated using in vitro MTT assay, intra-macrophage model, and gene expression profile. From the results obtained, no cytotoxicity effect was observed for niosomal and simple forms of drugs, as alone or in combination. Niosomal formulations of the drugs significantly showed more inhibitory effects (P≤0.001) than the simple drugs when the selectivity index was considered. The gene expression levels of Interleukin (IL-10) significantly decreased, while the level of IL-12 and metacaspase significantly increased (P≤0.001). The results of the present study showed that selenium plus glucantime niosome possess a potent anti-leishmanial effect and enhanced their lethal activity as evidenced by the in vitro experiments.

Antileishmanial Effect of Coffea arabica, Salvia rhytidea and Bunium persicum against Leishmania major and Leishmania tropica Promastigotes and Their Cytotoxicity and Antioxidant Activities

Aims: This study was aimed to use Coffea arabica, Salvia rhytidea and Bonium persicum extracts against Leishmania major and L. tropica promastigotes to compare various concentrations of these plant extracts. In addition, their cytotoxicity and antioxidant activities were also evaluated. Study Design: This study was performed experimentally using various concentrations of three medicinal plant extracts compared to control groups. Methodology: Fresh seeds of C. arabica and B. persicum and leaves of S. rhytidea were powdered and each plant material was extracted by ethyl alcohol via warm maceration method. Complete medium was used to prepare nine final concentrations (1-1000 µg/ml) for experiments. The cytotoxicity and antioxidant activities of the ethanolic extracts were evaluated using colorimetric cell viability WST1 and DPPH assays. All experiments were performed in triplicate and analyzed by t-test. The optical density (OD) values as measured by enzyme-linked immunosorbent assay (ELISA) were used to calculate the IC50 values. Selectivity index (SI) of the plant extracts was not attributed to cytotoxicity when it was ≥ 10. Results: The results indicated that B. persicum extract had potent antileishmanial activity against the promastigotes of both Leishmania species based on a dose-dependent response (

Leishmanicidal compounds of Nectria pseudotrichia, an endophytic fungus isolated from the plant Caesalpinia echinata (Brazilwood)

BACKGROUND In a screen of extracts from plants and fungi to detect antileishmanial activity, we found that the ethyl acetate extract of the fungus Nectria pseudotrichia, isolated from the tree Caesalpinia echinata (Brazilwood), is a promising source of bioactive compounds. OBJECTIVES The aims of this study were to isolate and determine the chemical structures of the compounds responsible for the antileishmanial activity of the organic extract from N. pseudotrichia. METHODS Compounds were isolated by chromatographic fractionation using semi-preparative high-performance liquid chromatography, and their chemical structures were determined by analytical and spectral data and by comparison with published data. The antileishmanial activity of the isolated compounds was evaluated in intracellular amastigote forms of Leishmania (Viannia) braziliensis expressing firefly luciferase as reporter gene, and cytotoxicity was determined in Vero and THP-1 mammalian cell lines by MTT assay. FINDINGS Fractionation of the extract yielded seven compounds: 10-acetyl trichoderonic acid A (1), 6′-acetoxy-piliformic acid (2), 5′,6′-dehydropiliformic acid (3), piliformic acid (4), hydroheptelidic acid (5), xylaric acid D (6), and cytochalasin D (7). Compounds 1, 2 and 3 are reported here for the first time. Compounds 1, 2, and 5 were more active, with IC50 values of 21.4, 28.3, and 24.8 µM, respectively, and showed low toxicity to Vero and THP-1 cells. MAIN CONCLUSIONS N. pseudotrichia produces secondary metabolites that are more toxic to intracellular amastigote forms of L. (V.) braziliensis than to mammalian cells.

4-Phenyl-1, 3-thiazole-2-amines as scaffolds for new antileishmanial agents

There is still a need for new alternatives in pharmacological therapy for neglected diseases, as the drugs available show high toxicity and parenteral administration. That is the case for the treatment of leishmaniasis, particularly to the cutaneous clinical form of the disease. In this study, we present the synthesis and biological screening of eight 4-phenyl-1,3-thiazol-2-amines assayed against Leishmania amazonensis. Herein we propose that these compounds are good starting points for the search of new antileishmanial drugs by demonstrating some of the structural aspects which could interfere with the observed activity, as well as suggesting potential macromolecular targets. Methods: The compounds were easily synthesized by the methodology of Hantzsch and Weber, had their purities determined by Gas Chromatography-Mass spectrometry and assayed against the promastigote forms of Leishmania amazonensis as well as against two white cell lines (L929 and THP-1) and the monkey's kidney Vero cells. PrestoBlue® and MTT viability assays were the methodologies applied to measure the antileishmanial and cytotoxic activities, respectively. A molecular modeling target fishing study was performed aiming to propose potential macromolecular targets which could explain the observed biological behavior. Results: Four out of the eight compounds tested exhibited important anti-promastigote activity associated with good selectivity indexes when considering Vero cells. For the most promising compound, compound 6, IC50 against promastigotes was 20.78 while SI was 5.69. Compounds 3 (IC50: 46.63 µM; SI: 26.11) and 4 (IC50: 53.12 µM; SI: 4.80) also presented important biological behavior. A target fishing study suggested that S-methyl-5-thioadenosine phosphorylase is a potential target to these compounds, which could be explored to enhance activity and decrease the potential toxic side effects. Conclusions: This study shows that 4-phenyl-1,3-thiazol-2-amines could be good scaffolds to the development of new antileishmanial agents. The S-methyl-5-thioadenosine phosphorylase could be one of the macromolecular targets involved in the action.(AU)

Neolignans isolated from twigs of Nectandra leucantha Ness & Mart (Lauraceae) displayed in vitro antileishmanial activity

The therapeutic arsenal for the treatment of Leishmaniasis is limited and includes toxic compounds (antimonials, amphotericin B, pentamidine and miltefosine). Given these aspects, the search for new compounds based on floristic biodiversity is crucial. In the present work, we report the isolation, characterization and antileishmanial activity of six related neolignans (1­6) of bioactive extract from Nectandra leucantha (Lauraceae) twigs. Methods: Dried and powdered twigs of N. leucantha were exhaustively extracted using n-hexane. The crude extract was dereplicated by HPLC/HRESIMS and subjected to column chromatography to yield pure compounds 1­6. Their chemical structures were identified via NMR and comparison of obtained data with those previously published in the literature. Biological assays of compounds 1­6 and their respective monomers (eugenol and methyleugenol) were performed using promastigote and amastigote forms of Leishmania (L.) infantum. Results: Dereplication procedures followed by chemical characterization of isolated compounds by NMR enabled the identification of related neolignans 1­6. Neolignans 2, 4 and 6 showed potential against amastigote forms of L. (L.) infantum (EC50 values of 57.9, 67.7 and 13.7 µM, respectively), while compounds 1 and 3 were inactive. As neolignans 2­4 are chemically related, it may be suggested that the presence of the methoxyl group at C4 constitutes an important structural aspect to increase antileishmanial potential against amastigote forms. Compound 6, which consists of a methylated derivative of compound 5 (inactive) showed antileishmanial activity similar to that of the standard drug miltefosine (EC50 =16.9 µM) but with reduced toxicity (SI = 14.6 and 7.2, respectively). Finally, two related monomers, eugenol and methyleugenol, were also tested and did not display activity, suggesting that the formation of dimeric compounds by oxidative coupling is crucial for antiparasitic activity of dimeric compounds 2, 4 and 6. Conclusion: This study highlights compound 6 against L. (L.) infantum amastigotes as a scaffold for future design of new compounds for drug treatment of visceral leishmaniasis.(AU)

In vitro and in vivo antileishmanial activity of Artemisia annua L. leaf powder and its potential usefulness in the treatment of uncomplicated cutaneous leishmaniasis in humans

ABSTRACT INTRODUCTION: Cutaneous leishmaniasis (CL) is a tropical disease that affects millions of individuals worldwide. The current drugs for CL may be effective but have serious side effects; hence, alternatives are urgently needed. Although plant-derived materials are used for the treatment of various diseases in 80% of the global population, the validation of these products is essential. Gelatin capsules containing dried Artemisia annua leaf powder were recently developed as a new herbal formulation (totum) for the oral treatment of malaria and other parasitic diseases. Here, we aimed to determine the usefulness of A. annua gel capsules in CL. METHODS: The antileishmanial activity and cytotoxicity of A. annua L. capsules was determined via in vitro and in vivo studies. Moreover, a preliminary evaluation of its therapeutic potential as antileishmanial treatment in humans was conducted in 2 patients with uncomplicated CL. RESULTS: Artemisia annua capsules showed moderate in vitro activity in amastigotes of Leishmania (Viannia) panamensis; no cytotoxicity in U-937 macrophages or genotoxicity in human lymphocytes was observed. Five of 6 (83.3%) hamsters treated with A. annua capsules (500mg/kg/day) for 30 days were cured, and the 2 examined patients were cured 45 days after initiation of treatment with 30g of A. annua capsules, without any adverse reactions. Both patients remained disease-free 26 and 24 months after treatment completion. CONCLUSION: Capsules of A. annua L. represent an effective treatment for uncomplicated CL, although further randomized controlled trials are needed to validate its efficacy and safety.

Antioxidant antileishmanial cytotoxic and antimicrobial activities of a local plant Myrtus nivellei from Algeria Sahara

Objective To study the phytochemical constituents and in vitro biological activities of hydromethanolic extract and fractions from Algerian Sahara Myrtus nivellei (M. nivellei) collected in Hoggar region and to identify the active fraction that can act as an alternative of commonly used antibiotics and as antileishmanial or antioxidant agents. Methods Phytochemical screening of M. nivellei aerial parts was realised according to the literature. Extract was firstly prepared by using aqueous methanol then fractionated with ethyl acetate and butanol solvents. Total phenolics, tannis and flavonoids, of the hydromethanolic extract and their fractions were determined by Folin–Ciocalteu method as gallic acid equivalents and by aluminium chloride as rutin equivalent respectively. Extract and fractions were tested for their antimicrobial and antiparasital activities against standard bacteria using agar diffusion method and two kinds of leishmania visceral and cutaneous. The antioxidant activities were realized using phosphomolybdenum, FRAP and DPPH tests. Results Preliminary phytochemical screening exhibited the presence of flavonoids, tannins, saponins, and alkaloids. The experimental results showed that plant extract and fractions were high in phenolic compounds and exhibited an important role as antioxidant, antimicrobial and had a moderate antileishmanial activity. Conclusions These observations lead us toward more studies in this field, so that we can get more benefits from our local Algerian medicinal plants.

In Vitro Assessment of Antileishmanial Activity of Natamycin and Nystatin

ABSTRACT The present study was aimed to evaluate the in vitro antileishmanial activity of four different concentrations of natamycin and nystatin by using MTT 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyl tetrazolium bromide reduction assay. In vitro antileishmanial activity revealed that the IC50 of natamycin (80.49 μg/ml) and nystatin (105.7 μg/ml) was less than that of sodium stibogluconate (127.9 μg/ml), and more than amphotericin B (18.91 μg/ml).

Antioxidant antileishmanial cytotoxic and antimicrobial activities of a local plant Myrtus nivellei from Algeria Sahara

Objective: To study the phytochemical constituents and in vitro biological activities of hydromethanolic extract and fractions from Algerian Sahara Myrtus nivellei (M. nivellei) collected in Hoggar region and to identify the active fraction that can act as an alternative of commonly used antibiotics and as antileishmanial or antioxidant agents. Methods: Phytochemical screening of M. nivellei aerial parts was realised according to the literature. Extract was firstly prepared by using aqueous methanol then fractionated with ethyl acetate and butanol solvents. Total phenolics, tannis and flavonoids, of the hydromethanolic extract and their fractions were determined by Folin–Ciocalteu method as gallic acid equivalents and by aluminium chloride as rutin equivalent respectively. Extract and fractions were tested for their antimicrobial and antiparasital activities against standard bacteria using agar diffusion method and two kinds of leishmania visceral and cutaneous. The antioxidant activities were realized using phosphomolybdenum, FRAP and DPPH tests. Results: Preliminary phytochemical screening exhibited the presence of flavonoids, tannins, saponins, and alkaloids. The experimental results showed that plant extract and fractions were high in phenolic compounds and exhibited an important role as antioxi-dant, antimicrobial and had a moderate antileishmanial activity. Conclusions: These observations lead us toward more studies in this field, so that we can get more benefits from our local Algerian medicinal plants.

Antileishmanial activities of caffeic acid phenethyl ester loaded PLGA nanoparticles against Leishmania infantum promastigotes and amastigotes in vitro

Objective To investigate and compare the antileishmanial effects of CAPE and (CAPE)

Antileishmanial activities of caffeic acid phenethyl ester loaded PLGA nanoparticles against Leishmania infantum promastigotes and amastigotes in vitro

OBJECTIVE@#To investigate and compare the antileishmanial effects of CAPE and (CAPE) on Leishmania infantum (L. infantum) promastigotes and amastigotes in vitro.@*METHODS@#Efficacies of CAPE, (CAPE) and free PLGA nanoparticles (NPs) on promastigotes were evaluated using MTT and promastigote count assays, and their anti-amastigote effects were determined via infection index analysis. Griess reaction was also performed to calculate nitric oxide production of macrophages exposed to investigated molecules.@*RESULTS@#It was determined that CAPE and (CAPE) demonstrated significant inhibitory effects on L. infantum promastigotes and amastigotes, while free NPs did not exhibit any meaningful antileishmanial effectiveness. The IC values of CAPE for L. infantum promastigotes and amastigotes were assessed as (51.0 ± 0.8) and (19.0 ± 1.4) μg/mL, respectively (P < 0.05). On the other side, it was revealed that (CAPE) had superior antileishmanial activity on both forms of parasites since its IC values for L. infantum promastigotes and amastigotes were (32.0 ± 1.3) and (8.0 ± 0.9) μg/mL, respectively (P < 0.05). It was also determined that both agents strongly stimulated nitric oxide production of macrophages.@*CONCLUSIONS@#The obtained results show that (CAPE) have a great potential to be especially used in treatment of visceral leishmaniasis; however, in vivo antileishmanial screening of these molecules should be performed in the near future.

In vivo antileishmanial activity and chemical profile of polar extract from Selaginella sellowii

The polar hydroethanolic extract from Selaginella sellowii(SSPHE) has been previously proven active on intracellular amastigotes (in vitro test) and now was tested on hamsters infected with Leishmania (Leishmania) amazonensis (in vivo test). SSPHE suppressed a 100% of the parasite load in the infection site and draining lymph nodes at an intralesional dose of 50 mg/kg/day × 5, which was similar to the results observed in hamsters treated with N-methylglucamine antimonate (Sb) (28 mg/Kg/day × 5). When orally administered, SSPHE (50 mg/kg/day × 20) suppressed 99.2% of the parasite load in infected footpads, while Sb suppressed 98.5%. SSPHE also enhanced the release of nitric oxide through the intralesional route in comparison to Sb. The chemical fingerprint of SSPHE by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry showed the presence of biflavonoids and high molecular weight phenylpropanoid glycosides. These compounds may have a synergistic action in vivo. Histopathological study revealed that the intralesional treatment with SSPHE induced an intense inflammatory infiltrate, composed mainly of mononuclear cells. The present findings reinforce the potential of this natural product as a source of future drug candidates for American cutaneous leishmaniasis.