Effect Of Micro-Derived Antioxidantson Mammary Oxidative Damage Induced By High-Fat Diet In Breeding Rats

This study was designed to investigate the effects of micro-derived antioxidants（MA）on mammary gland oxidative damage and mammary gland function induced by high-fat diet.Forty-eight SD pregnant rats were randomly divided into A（basal diet group）,B（high-fat diet group,80%A+20%lard）,C（MA group,98%A+2%MA）and D（repair group,78%A+20%lard+2%MA）,12 rats in each group.The body weight and feed intake at each stage of the female rats were recorded.On the first and the 10^th lactation day,female rats’blood,milk and mammary gland were collected to determinate indexes,including the antioxidative indexes in plasma and mammary gland,PRL in plasma,Ig G in milk and MAPK signal pathway related gene expression with protein phosphorylation level in mammary gland.The results showed that compared with the group A,1)the activity of T-AOC,GSH-Px,CAT and the level of IHA in plasma and mammary gland of group B female rats were significantly decreased（p<0.05）,while the concentration of MDA was significantly increased（p<0.05）;2)feed intake of female rats in group C female rats was significantly decreased（p<0.05）,while weight gain were significantly increased（p<0.05）during lactation period;3)the weight gain of offsprings in group C was decreased（p<0.05）during lactation period.Compared with the group B,1)body weight of female rats increased significantly（p<0.05）in group D,but the weight gain of pups was decreased significantly（p<0.05）;2)the PRL level in plasma and Ig G level in milk were significantly increased on the first day of lactation（p<0.05）in group D female rats;3)the content of PC in plasma and mammary gland was significantly lower（p<0.05）than these in group D female rats;4)the activities of SOD,GSH-Px,CAT and the level of IHA in female rats were significantly increased（p<0.05）in group D female rats;5)the relative expression levels of m RNA for MEK1,MEK2,MKK6,MKK4 and MKK7 on the first lactation day and MKK7 on the 10^th lactation day were significantly increased in mammary gland（p<0.05）,while the relative expression levels of m RNA for MEK1 and MEK2 were significantly decreased on the 10^th lactation day（p<0.05）in mammary gland in group D;6)the Erk1/2 protein phosphorrylation level was significantly increased on the 10th lactation day（p<0.05）in mammary gland of group D.In summary,high-fat diets induced oxidative stress in maternal rats and oxidative damage in mammary gland.MA increased the antioxidative ability of high-fat induced reproductive females and alleviated oxidative damage induced by high-fat and increased the content of Ig G in milk,and the PRL level in plasma was increased in the first day of lactation.Erk1/2 and JNK signaling pathways are activated during oxidative damage in mammary gland,suggesting that MA might play a regulatory role through Erk1/2 and JNK pathways.