In vivo efficacy of calceolarioside a against experimental visceral leishmaniasis

Bioactivity-guided fractionation has led to the successful isolation of calceolarioside A (1) from the methanolic extract of night jasmine leaves. The in vitro antileishmanial activity of compound 1 was determined (IC50=20 mu g/mL). Its in vivo efficacy was noted at 20 mg/kg body weight when it reduced the hepatic and splenic parasite burden by 79 and 84%, respectively, in an established model of L. donovani Ag83 infected golden hamster. Furthermore, synergistic potentiations of compound 1 at 20 mg/kg body weight and SAG at 5 mg/kg body weight showed a significant reduction of hepatic and splenic parasite burden. No cytotoxicity was observed against the U937 cell line. This is the first report describing the isolation of compound 1 from N. arbor-tristis L. and the first demonstration of its potent activity against visceral leishmaniasis.