Inhibitory effect of baicalin on proliferation of A549 cells and possible mechanism

Objective To investigate the eftects of baicalin on proliferation of cells-line-AS49 and its action mechanism.Methods Cultured A549 cells were treated with baicalin (0.000,0.625,1.250,2.500,5.000,10.000 mg/L) for 24,48 and 72 h,then inhibition rate was measured by methyl thiazol tetrazolium (MTT) assay.Cells treated with 1.22 mg/L baicalin for 24 h were collected and subjected to reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting for the expression levels of proliferating cell nuclear antigen (PCNA),Cyclin D1 and p21.Results MTT indicated that the proliferation of A549 cells was inhibited by baicalin at different concentrations.As compared with control group (0.68 ±0.16,0.48 ±0.05,0.27 ±0.06),PCNA mRNA (0.22 ±0.03) abd Cyclin D1 mRNA (0.08 ± 0.02) were down-regulated,and p21 mRNA (0.47 ± 0.07 ) was up-regulated markedly by 1.22 mg/L baicalin for 24 h. As compared with control group (1.75 ±0.05,1.59 ±0.24,0.59±0.02),PCNA protein (0.34 ± 0.02 ) and Cyclin D1 protein (0.50 ± 0.02 ) were down-regulated,and p21 protein (1.39 ± 0.05) was up-regulated by baicalin.Conclusion Baicalin inhibits A549 cells proliferation by down-regulating the expression of PCNA and Cyclin D l,and by up-regulating the expression of p21. Key words: Pneumonic adenocarcinoma; Baicalin; Proliferating cell nuclear antigen