Effect of berberine on proliferation, cell cycle and apoptosis in HeLa and L1210 cells

Previous studies on the anticancer activity of protoberberine alkaloids against a variety of cancer cell lines were extended to human tumour HeLa and murine leukemia L1210 cell lines. An attempt was also made to investigate the relationship between the cytotoxic activity of berberine and its molecular mechanism of action. Cytotoxicity was measured in-vitro using a primary biochemical screening according to Oyama and Eagle, and the growth inhibition assay. The in-vitro cytotoxic techniques were complemented by cell cycle analysis and determination of apoptotic DNA fragmentation in L1210 cells. Berberine acted cytotoxically on both tumour cell lines. The sensitivity of leukemia L1210 cells to the berberine was higher than that of HeLa cells. The IC100 was below 100 mug mL(-1) for HeLa cells and approached a 10 mug mL(-1) limit for the leukemia L1210 cells. For both cell lines the IC50 was found to be less than 4 mug mL(-1), a limit put forward by the National Cancer Institute (NCl) for classification of the compound as a potential anticancer drug. In L1210 cells treated with 10-50 mug mL(-1) berberine, G(0)/G(1) cell cycle arrest was observed. Futhermore, a concentration-dependent decrease of cells in S phase and increase in G(2)/M phase was detected. In addition, apoptosis detected as sub-Go cell population in cell cycle measurement was proved in 25-100 mug mL(-1) berberine-treated cells by monitoring the apoptotic DNA fragmentation (DNA ladder) using agarose gel electrophoresis.