Effects of baicalin on CA46 cell proliferation inhibition and apoptosis induction

AIM: To investigate the effects of baicalin on proliferation inhibition and apoptosis induction in human Burkitt lymphoma cell line CA46 and to explore its underlying mechanisms. METHODS: CA46 cells were exposed to baicalin at different dosages and its proliferation inhibition was detected by MTT assay. The ability of baicalin to induce CA46 cell apoptosis was examined by Annexin V-FITC/PI double staining analysis, TUNEL labeling method and DNA fragmentation. The mRNA expressions of c-myc and bcl-2 were detected by RT-PCR, and the protein expressions of c-Myc, Bcl-2, caspase-3 precursor (procaspase-3) and poly ADP-ribose polymerase (PARP) were detected by Western blotting. RESULTS: Baicalin remarkably inhibited the CA46 cell proliferation, with an IC50 value of 10 μmol/L. Apoptosis was remarkably induced by baicalin in a dose-dependent manner, and its earlier and later stages were detected by annexin V-FITC/PI double staining analysis, TUNEL labeling method and DNA fragmentation, respectively. Furthermore, RT-PCR showed that the mRNA expressions of c-myc and bcl-2 in treated CA46 cells decreased in a time-dependent manner. Western blotting showed that the protein expressions of c-Myc, Bcl-2, procaspase-3 and PARP (116 kD) in baicalin treated CA46 cells were down-regulated in a time-dependent manner, while the expression of PARP(85 kD) was up-regulated. CONCLUSION: Baicalin efficiently induces proliferation inhibition and apoptosis in CA46 cells, which may be related with the down-regulation of c-Myc and Bcl-2 expressions, as well as the up-regulation of caspase-3 activity.