Curcuma caesia rhizome extract shows selective cytotoxicity and antiproliferative effect against lung and breast cancer cell lines

Background: Black turmeric (Curcuma caesia Roxb.) exhibits various pharmacological properties, including anticancer, antifungal, and antibacterial activities. Objective: This study evaluates the cytotoxic and antiproliferative potential of crude methanolic rhizome extracts of black turmeric in selected cell lines. Materials and methods: The crude methanolic extract was prepared by the Soxhlet extraction method. Short-term cytotoxicity was determined by Trypan blue exclusion method in murine cancer cells (DLA and EAC), whereas in vitro cytotoxicity was determined by MTT assay in human cancer cell lines (Breast and lung cancer cells). The antiproliferative effect and induction of apoptotic machinery were measured by clonogenic assay, and DNA laddering assay respectively. Results and conclusion: The Trypan blue exclusion assay demonstrated IC50 values of 207.69 ± 18.74 µg/ml and 122.35 ± 1.29 µg/ml in Ehrlich Ascites Carcinoma (EAC) and Dalton’s Lymphoma Ascites (DLA) cells respectively. Cytotoxicity assessment of the methanolic extract in A549 and MDA-MB-231 cell lines yielded IC50 values of 100.14±0.56 µg/ml and 165.43±1.76 µg/ml respectively, with negligible toxicity to normal cell line. The clonogenic assay revealed significant inhibition of colony formation with the crude extract suppressing colony formation by 80.2% in A549 cells and complete inhibition in MDA-MB-231 cells at IC50 concentration. DNA fragmentation analysis of the treated cell lines for apoptosis showed no visible DNA shearing in agarose gel electrophoresis. Conclusion: The crude methanolic extract of C. caesia showed a significant cytotoxic effect against murine and human cancer cells. It significantly reduced colony formation, particularly in MDA-MB-231 cells. The mechanism of action needs to be elucidated.