Antioxidant, cytotoxic and antineoplastic effects of Carissa carandas Linn. leaves

For scientific clarification of some traditional uses, this study was designed to explore the antioxidant, cytotoxic and antineoplastic properties of leaf extract of Carissa carandas Linn., a traditional medicinal plant of Bangladesh. The methanol extract of Carissa carandas leaves (MELC) was applied on DPPH and ABTS experiments to determine its antioxidant activity. In vitro the cytotoxic effect of MELC was evaluated against colonic adenocarcinoma cell lines (SW-480 and SW-48) whereas in vivo its antineoplastic property was tested against Ehrlich ascites carcinoma (EAC). The DPPH and ABTS assays revealed the antioxidant activity of MELC with IC50 10.5 +/- 1.2 and 1.75 +/- 0.3 mu g/ml that was comparable to L-ascorbic acid. In vitro cytotoxic study, MELC reduced the viability of adenocarcinoma cells in dose dependent manner and in vivo, administration of MELC (25 mg/kg) resulted in a significant (p < 0.05) decrease in viable EAC cell count thereby increasing the life span of the EAC cell bearing mice. Restoration of hematological parameters such as red blood cells (RBC), hemoglobin and white blood cells (WBC) to normal levels in MELC-treated mice was also observed. Moreover, treatment with MELC induced apoptosis of EAC cells as observed in fluorescence microscopic view of DAPI (4,6-diamidino-2-phenylindole) stained cells and also increased p53 gene expression MELC-treated cells in respect to untreated EAC control. In addition, the MELC was rich in polyphenol content and its GC MS chromatogram confirmed the presence of some compounds all of which showed anticancer and cytotoxic activities in previous studies. In a word, this study supports the use of Carissa carandas in traditional medicine as well as highlights the need to further explore the potentials of MELC as an antineoplastic agent.