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.
Keywords: adiponectin; antioxidant capacity; glycolipid metabolism; n-6/n-3 polyunsaturated fatty acid ratio.