[Effects of different ratios of n-6/n-3 polyunsaturated fatty acid on adiponectin, glycolipid metabolism and antioxidant capacity in high fat-diet fed rats].

OBJECTIVE

To investigate effects of different ratios of n-6/n-3 Polyunsaturated fatty acid(PUFA) on adiponectin, glycolipid metabolism and antioxidant capacity in high fat-diet fed rats.

METHODS

Fixty male Wistar rats were randomly divided into control group(CON, 17% energy from fat, n-6/n-3 PUFA=5∶1) and high-fat treatment groups(1∶1 group∶n-6/n-3 PUFA=1∶1, 5∶1 group, n-6/n-3 PUFA=5∶1, 10∶1 group∶ n-6/n-3 PUFA=10∶1 and 20∶1 group∶ n-6/n-3 PUFA=20∶1, 42% energy from fat). Rats were fed for 12 week. Serum glucose and lipid(0, 4, 8 and 12 week) were detected. Antioxidant indexes(0 and 12 week), adiponectin mRNA and protein expressions in epididymal adipose tissues as well as serum adiponectin(12 week) were measured.

RESULTS

Baseline data showed no significant inter-group difference(P>0. 05). 1∶1 and 5∶1 showed no significant changes in serum glucose compared with control at all time points(P>0. 05), while 10∶1 and 20∶1 significantly increased it at the 12 th week(P<0. 05). At the 12 th week, total cholesterol(TC) and triglycerides(TG) in high-fat treatment groups were significantly higher than control(P<0. 01), with 20∶1 showing significant increment of TG compared with other high-fat treatment groups(P<0. 01). At the 12~(th) week, glutathione peroxidase and superoxide dismutase content in high-fat treatment groups all decreased significantly compared with control(P<0. 05), and 20∶1 decreased most. Malondialdehyde content significantly increased in high-fat treatment groups(P<0. 05), and 10∶1 increased most. Adiponectin mRNA expression significantly decreased in 20∶1 compared with control, 1∶1 and 5∶1(P<0. 05). Increment of adiponectin protein expression was significantly shown in 5∶1 compared with other high-fat treatment groups(P<0. 05), while it was most obviously decreased in 20∶1(P<0. 05).

CONCLUSION

Lower n-6/n-3 PUFA ratios(1∶1 and 5∶1) contributed to improvement of glycolipid metabolism and antioxidant capacity as well as increment of adiponectin expression of rats fed with high-fat diet.