Cytotoxicity against tumor cell lines of a ribosome-inactivating protein (RIP)-like protein isolated from leaves of Mirabilis jalapa L

The 30 kD protein fraction with properties like ribosome-inactivating protein (RIP) was isolated from the leaves of Mirabilis jalapa L. and named MJ-30. This study investigated the cytotoxic effect of MJ-30 on normal and malignant cells. MJ-30 was isolated from the leave extract of M. jalapa L. using cation-exchange chromatography with CM Sepharose CL-6B column to obtain MJ-30. The fraction contain DNA cleaving ability were pooled and checked for cytotoxicity against breast cancer T47D cell line, cervical cancer SiHa cell line, and human mononuclear cells derived from peripheral blood of healthy volunteers. Results showed that the MJ-30 produced cytotoxic effect against T47D and SiHa cell line to different extent. The LC50 of the MJ-30 on T47D cell line and SiHa cell line were 0.36 μg/mL and 5.6 μg/mL, respectively. While in normal cells, represented by human mononuclear cells, MJ-30 was considerably less toxic, with LC50 of 21.04 μg/mL. The results suggest that MJ-30 produced more cytotoxic activity toward breast and cervical cancer cells (58-fold and 4-fold, respectively) as compared to normal mononuclear cells