Objective: Alysicarpus monilifer (Family Papilionaceae) has been used in the Indigenous system of medicine in tumor removal. The present study was designed to isolate and identify the constituent responsible for cytotoxic (anti-tumor) effects of the plant Alysicarpus monilifer.

Methods: The plant was powdered and extracted to give a methanolic extract. Initially, Hexane, chloroform, ethyl acetate and methanolic fractions of the methanolic extract of the plant were subjected to cytotoxic screening using cell line based assay (MTT assay and NRU assay). The chloroform fraction showed significant cytotoxicity, so it was further subjected to column chromatography, to separate the cytotoxic phytoconstituent. The cell lines selected were breast cancer cells (MCF-7 and MDA-MB-468) and Liver cancer cells (HepG2 and HLE cell). Results were calculated as percentage growth inhibition with respect to untreated (control) cells versus treated cells.

Result: A triterpene, Betulinic acid, was isolated from the aerial parts of Alysicarpus monilifer. The cytotoxic activity of the identified compound against MCF-7, MDA-MB-231, HLE and HepG2 cells was also found to be highly significant with 90% growth inhibition.

Conclusion: The triterpene was identified to be betulinic acid, to which the cytotoxic activity can be attributed. It is a first report of isolation of betulinic acid from the Alysicarpus species.