Betulinic acid exhibits stronger cytotoxic activity on the normal melanocyte NHEM-neo cell line than on drug-resistant and drug-sensitive MeWo melanoma cell lines.

Betulinic acid is a triterpene isolated from the bark of many plants that exhibits cytotoxicity in several cancer cell lines and is capable of inducing apoptosis. In this study, we examined the cytotoxic activity and apoptotic ability of betulinic acid in the drug-sensitive (MeWo) and drug-resistant melanoma MeWo CIS (cisplatin), MeWo ETO (etoposide), MeWo VIN (vinblastin) and MeWo FOTE (fotemusine) cell lines, as well as in the normal melanocyte NHEM-neo cell line. The results show that betulinic acid exhibited significant cytotoxicity on all the cell lines. However, a sulphorhodamine B cell proliferation assay and immunocytochemical analysis of Ki67 expression revealed the strongest cytotoxicity on the normal melanocyte cell line, NHEM-neo. Flow cytometry and immunocytochemical analysis of caspase 3 expression was used to confirm cell death by apoptosis. In conclusion, betulinic acid is a potential candidate for anticancer research, and may also have an application in the cosmetics industry.