Cytotoxic Activity of Holothuria leucospilota Extract against Leishmania infantum In Vitro.

Leishmaniasis is a tropical parasitic infection. The resistance and toxicity issues are the major complications and remain significant consequences related to the treatment of leishmaniasis with the recent and classical drugs. Thus there is an immediate requirement to develop new compounds for the treatment of this protozoan disease. Sea cucumbers or holothurians are potentially presented as the marine sources of antimicrobial and cytotoxic compounds. The aim of this study was investigation of in vitro antileishmanial activity of methanol extract of body wall, coelomic fluid, and cuvierian organs of Holothuria leucospilota obtained from coastal parts of Persian Gulf against Leishmania infantum promastigotes and axenic amastigotes. The colorimetric MTT assay was used to determine L. infantum promastigotes and axenic amastigotes viability at different concentrations of the extracts and drug control (Glucantime®) at time dependent manner and the results are represented as IC50 (50% of inhibitory concentration). Coelomic fluid was the most active extract among the three different extracts of H. leucospilota against L. infantum promastigotes and axenic amastigotes with IC50s of 62.33 µg/mL and 22.4 µg/mL and 73 µg/mL and 46 µg/mL at 48 and 72 hours after treatment, respectively. Cuvierian organs extract showed less toxicity with IC50s more than 1000 µg/mL for both Leishmania infantum axenic amastigotes and promastigotes forms after 48 and 72 hours of exposure. Results acquired from the present study propose that the sea cucumber H. leucospilota may be a provoking source of antileishmanial compounds and could be a lead source in the development of the potent antileishmanial and cytotoxic drugs.

In vitro activity and cytotoxicity of Crocus sativus extract against leihmania major (MRHO/IR/75/ER).

Leishmaniasis is a complex protozoan disease comprising a wide range of clinical manifestations that is usually divided into visceral leishmaniasis, cutaneous leishmaniasis, and muco-cutaneous leishmaniasis depending on leishmania parasite species and host's immune system responses. Most of the drugs produced for the treatment of leishmaniasis, from the first used to the most recently accepted, are toxic, resistance issues and poorly tolerated. The purpose of this study is to evaluate the effectiveness of saffron (Crocus sativus) and its apoptotic activity against Leishmania major (MRHO/IR/ 75/ER) promastigotes. MTT assay was used to find viability of L. major promastigotes and the achieved results were explicated as IC50 (50% inhibitory concentration). ED50 (50% effective doses) for L. major amastigotes were also analyzed. Annexin-V FLUOS staining was performed to study the cell death properties of saffron by using FACS analysis. Qualitative analysis of the DNA fragmentations was accomplished by agarose gel electrophoresis and light microscopy was used to observe morphological changes of promastigotes. Our results revealed that L. major promastigotes and amastigotes are sensitive to saffron at different concentrations and time dependent manner with apoptotic features including DNA laddering, cytoplasmic shrinkage, and externalization of phosphatidylserine. IC50 and ED50 of this extract after 48 h of incubation was 0.7mg/ml and 0.5 mg/ml respectively. Finally, C. sativus has shown anti-leishmanial activity against L. major promastigote and amastigote and may induce apoptosis.

In silico and in vitro comparative activity of novel experimental derivatives against Leishmania major and Leishmania infantum promastigotes.

This in silico and in vitro comparative study was designed to evaluate the effectiveness of some biurets (K1 to K8) and glucantime against Leishmania major and Leishmania infantum promastigotes. Overall, eight experimental ligands and glucantime were docked using AutoDock 4.3 program into the active sites of Leishmania major and Leishmania infantum pteridine reductase 1, which were modeled using homology modeling programs. The colorimetric MTT assay was used to find L. major and L. infantum promastigotes viability at different concentrations of biuret derivatives in a concentration and time-dependent manner and the obtained results were expressed as 50% and 90% of inhibitory concentration (IC50 and IC90). In silico method showed that out of eight experimental ligands, four compounds were more active on pteridine reductase 1. K3 was the most active against L. major promastigotes with an IC50 of 6.8 µM and an IC90 of 40.2 µM, whereas for L. infantum promastigotes was K8 with IC50 of 7.8 µM. The phenylethyl derivative (K7) showed less toxicity (IC50s>60 µM) in both Leishmania strains. Glucantime displayed less growth inhibition in concentration of about 20 µM. In silico and especially docking results in a recent study were in accordance with the in vitro activity of these compounds in presented study and compound K3, K2 and K8 showed reasonable levels of selectivity for the Leishmania pteridine reductase 1.