Study on anti-senescence and anti-oxidation effects of soybean isoflavones in rats
HUANG Qiong, YANG Xing-fen, LI Wen-li, LI Zhi,HUANG Jun-ming, YANG Guo-guang, HUANG Jian-kang, ZHANG Bo (Guangdong Provincial Center for Disease Prevention and Control, Gunagdong Gunag zhou 510300, China)
To explore the anti-senescence and anti-oxidation effects of soybean i soflavones, aged SD rats were given various doses of soybean isoflavone and the change in their CD28 T-cell expression and MDA content in liver were observed. Thirty 12-month-old female rats were divided randomly into 3 groups: aged cont rol and 0.33, 0.99 g/kg BW soybean isoflavones groups. Another te n 2-month-old female rats were used as a young This work was supported by the Medicine of the Science and Technology research( A2002087) and the Major Medicine of the Science and Technology Program Funds [Yuewei246hao] of the Province of Guangdong, China. control group. The soybean isofl avone groups were given soybean isoflavones(0.33, 0.99g/kg BW) by gavage (1 ml/100 g BW)and the 2 control groups were given purified water of same volume by gavage once a day. After 4 weeks, the content of MDA an d the activity of SOD in liver were measured by reagent kits; levels of MMP and R OS in liver cells were measured by FACS; peripheral blood samples were collected for counting of CD28 T cell. Compared with the aged control group, the results showed that the contents of MDA in the liver of young control group and soybean isoflavone groups were significantly decreased(P0.05), the SOD activities, levels of MMP in the liver were significantly increased(P0.05)and the lev els of ROS in liver cells of soybean isoflavone groups were significantly decrea sed(P0.01). Compared with the young control group, the count of CD28+an d CD28+/CD8+ratio in the aged control group were lower and the CD28-/CD8 +ratio were higher. Compared with the aged control group, the count of CD28 +and the CD28+/CD8+ ratio in the soybean isoflavone groups were higher an d the ratio of CD28-/CD8+T cell lower. The results suggested that, in aged rats, the CD28 expression level, the stability of liver mitochondrial membrane a nd the ability to eliminate oxygen free radicals were all decreased and the end products of lipid peroxidation was increased. It is concluded that soybean iso f lavones can enhance the CD28 expression, increase the activity of antioxidant en zyme in liver and the stability of liver mitochondrial membrane and decrease the levels of ROS in liver cells of aged rats.