Journal of Vector Borne Diseases (Sep 2010)
Experimental chemotherapy with Allium sativum (Liliaceae) methanolic extract in rodents infected with Leishmania major and Leishmania donovani
Abstract
Background & objectives: Several plant products have been tested and found to possess antileishmanialactivity. The present study was undertaken to establish whether methanolic extract ofAllium sativum Linn has antileishmanial activity in comparison to standard drugs.Methods: Methanolic extract of A. sativum bulbs was screened for in vitro and in vivo antileishmanialactivity against Leishmania major strain (NLB 145) and L. donovani strain (NLB 065). Pentostam®and Amphotericin B® were used as standard drugs. BALB/c mice and golden hamsters(Mesocricetus auratus) were used in in vivo studies on L. major and L. donovani respectively.Results: The extract exhibited very low cytotoxicity (IC50 >450 μg/ml) against Vero cells. Theextract had significantly better (p <0.001) leishmanicidal activity against both species (IC50 34.22μg/ml to L. major, 37.41 μg/ml to L. donovani) than Pentostam. However, the activity wassignificantly lower (p <0.001) than that of Amphotericin B against both the species. At aconcentration of 250 μg/ml, the extract induced the production of 60 μM of nitric oxide, a ten-foldup-regulation in activated macrophages. The multiplication indices for L. major amastigotes treatedin 100 μg/ml were significantly different (p <0.05). Treatment with the extract, daily for 28 daysled to a significant reduction (p <0.05) in footpad swelling in BALB/c mice; similar activitynoticed in the treatment with standard drugs. The Leishman-Donovan Units (LDU) for the extracttreated animals were significantly higher (p <0.05) than those of standard drugs, but lower comparedto the negative control.Interpretation & conclusion: Since the mechanism of action for the methanolic extract is apparentlyimmunomodulatory, garlic compounds could be purified and tried as complementary medicine inthe management of leishmaniases.
