In vitro and in vivo efficacy of combination therapy using Allium sativum and Aloe secundiflora against Leishmania major infected BALB/c mice

Abstract

Allium sativum and Aloe secundiflora water extracts have antileishmanial activities. In the present study, the efficacy of combination therapy using A. sativum and A. secundiflora against L. major was studied both intraperitoneally and orally. The standard drug pentostam and phosphate buffered saline were used as positive and negative controls. T-test and ANOVA were used for data analysis and P-value of < 0.05 was considered significant. Plant materials were dried, ground soaked in water at 80 oC for 1 hour, filtered then freeze dried. The minimum inhibitory concentrations of aqueous extracts of A. secundiflora and A. sativum were 2000 μg/ml and 5000 μg/ml and IC50 were 467.09μg/ml and 457.88μg/ml respectively. The IC50 for their combination at ratio (1:1) was 391.79 μg/ml as compared to minimum inhibitory concentrations of 12.5μg/ml and IC50 of 108.58μg/ml for pentostam. The combination therapy had Infection rate of 17% and multiplication index of 48.65% compared to pentostam (IR=21% and MI=11.64%). The combination therapy reduced the footpad lesion size significantly (P<0.05) like the pentostam control drug and no significant nitric oxide stimulated. The oral and intraperitoneal combination treatment reduced spleen amastigotes in mice by 55.48% and 64.13% corresponding to total LDUs of 18.23±0.90and 14.69±1.33 respectively compared to pentostam 94.58% and LDU of 2.22±0.13. The combination therapy was less toxic, effective against L. major parasite, reduced lesion size significantly, reduced spleen parasite load significantly but did not prevent visceralization.