Effect of fucoidan on proliferation and apoptosis of human breast carcinoma cell line MCF-7

Objective:To investigate the effects of fucoidan on proliferation and apoptosis of breast carcinoma cell line MCF-7 and the underlying mechanism.Methods:Cell viability was measured by MTT assay.Apoptosis was detected by Hoechst 33258 staining and agarose gel electrophoresis.The mRNA and protein expression of bcl-2 and bax were examined by RT-PCR and Western blotting,respectively.Results:Fucoidan effectively inhibited the proliferation of MCF-7 cells in a concentration-dependent manner(P0.01).Fucoidan induced significant apoptosis of MCF-7 cells characterized by fragmented DNA ladder.Fucoidan down-regulated the expression of bcl-2 and up-regulated bax at mRNA and protein levels.The ratio of bcl-2 to bax decreased with the increase in the fucoidan concentrations(P0.05).Conclusion:Fucoidan inhibites the proliferation and induced the apoptosis of MCF-7 cells.The underlying mechanism may be related with down-regulation of anti-apoptotic protein bcl-2 and up-regulation of apoptotic protein bax.