Oxidative Stress in Apoptosis of Human Hepatocellular Carcinoma SMMC-7721 Cells Induced by Fucoidan

Abstract: To investigate the effect of fucoidan induced apoptosis in human hepatocellular carcinoma SMMC-7721 cells and the possible mechanism， the cellular viability of fucoidan on the cells was assessed by MTT assays in vitro.The change of the cell ultrastructure was detected by using transmission electron microscopy. Cellular apoptosis was measured by flow cytometry. The levels of GSH， MDA and the activity of SOD in the cells for 24 h treated with fucoidan were detected by spectro photometric assays. Western blot was used to analyze the expression of Bcl-2 and Bax proteins.The results showed that， fucoidan could inhibit the cells growth. The cells exhibit typical apoptotic features， including chromatin condensation and marginalization， nuclear fragmentation， decrease in number， swelling and vacuolization of mitochondrion. After 48 h with treatement 1 000 μg/mL fucoidan， the apoptotic ratio was significantly higher in the cells as compared with the control， the levels of cytosolic GSH and MDA increased and the activity of SOD decreased significantly (P<0.05). The expression of Bcl-2 was lower， and that of Bax was higher compared with the control. Our results indicated that intracellular GSH depletion， ROS accumulation， mitochondria oxidative damage and Bcl-2 protein down-expression，maybe closely correlated with the cells apoptosis induced by fucoidan.

CSTR: 32200.14.cjcb.2013.04.0007