ANTILEISHMANIAL ACTIVITY AND TOXICITY OF Momordica foetida SCHUMACH AND THONN EXTRACTS AGAINST Leishmania major

Abstract

Human leishmaniasis is a spectrum of diseases caused by protozoan parasites of the genus Leishmania. About 350 million people are at risk of infection, 15 million clinical cases, 1.5million annual incidence and 20- 30 thousand deaths occur annually. Treatment of leishmaniasis has traditionally relied on pentavalent antimonials which are toxic, expensive and are complicated by the variation in sensitivity of the Leishmania species and increasing levels of antimonial resistance. They also require protracted administration, and there is no vaccine at the moment, therefore, there is need for research for alternative and cheaper remedies including plant based drugs. The current study was to evaluate methanolic and aqueous extracts of Momordica foetida for antileishmanial activities and toxicity in Leishmania major infected BALB/c mice and in cell culture plates. The extracts were dried and re-dissolved in dimethyl sulfoxide (DMSO) 1% solvent before subjecting to L. major infected mice and cultures. Parasites inhibitions were then tested with serial concentration (0.07 to 19.9 mg ml-1) of the extracts. The lesion progression and body weight measurements were recorded weekly. Mice were sacrificed by injecting pentabarbitone sodium, the spleen of each mouse was weighed and splenic impression smears made on slides for microscopy evaluation of parasites. Data was analyzed using Statgraphic software and antileishmanial activities within and between all groups, the t-test and ANOVA being used respectively. The aqueous and methanolic extracts of M. foetida inhibited the parasites after 48 hrs incubation against L. major Amastigotes and promastigotes, demonstrating MIC of 125 ± 0.01 and 250 ± 0.03 mg/ ml and IC50 of 15.6±0.05 and 23.4±0.53mg/ml, respectively. The MIC of Pentostam and Amphotericin B was at the concentration of 62.5 ± 0.02 and 31.3 ± 0.01µg/ml with IC50 of 11.7 ± 0.054 and 7.8±0.053 mg/ml respectively. The Minimum inhibition concentration for aqueous extracts (125µg/ml) demonstrated higher inhibitory factor than that of methanolic extracts (250µg/ml) by 125 units. Increased concentration of M. foetida extracts did not stimulate the macrophages to produce sufficient amount of nitric oxide, hence the extracts could be having active compounds that acted directly on parasites. Considering M. foetida with no toxicity effects in BALB/c mice and vero cells it’s an indication that it’s safe for use in the chemotherapy of L. major. By showing antileishmanial activities with no toxicity, M. foetida extracts, therefore, supports its traditional use as an antileishmanial remedy and it should also be tested against other species of the parasite such as L. donovani, L. tropica and L. aethiopica.