Ethnobotanical information indicates that Indigofera conferta is used in northern Nigeria for the management of poisonous snakebites and the methanol extract was previously reported to have antivenin activity. In this study, we report the isolation of an oxyprenylated bioactive secondary metabolite; 2',4'- dihydroxy-4-prenyloxychalcone from the chloroform fraction of the aerial parts of the plant's methanol extract and the in vivo evaluation of the compound against Naja nigricollis venom. The compound has demonstrated significant (p < 0.05) and dose-dependent antivenin activity against LD99 Naja nigricollis venom. At a dose of 10 mg/kg, the compound protected 60% of the animals tested from death. The observed activity lends credence to the traditional use of the plant in the management of snake bites in northern Nigeria. The compound, 2',4'- dihydroxy-4-prenyloxychalcone, could also serve as a lead in the development of novel antisnake venom agents.
Keywords: Fabaceae; Indigofera conferta; antivenin; chalcone; isolation; snake venom.