Effect of dietary fish oil on enhanced inflammation and disturbed lipophagy in white adipose tissue caused by a high fat diet

Fish oil containing omega-3 polyunsaturated fatty acids (PUFA) attenuates chronic inflammation found in obesity, leading to a reduction in insulin resistance. The effect of fish oils containing omega-3 PUFA in the lipophagy pathway is unknown. In the present study, we examined whether omega-3 PUFA affects anti-inflammatory or lipophagy pathways in high fat diet-induced obesity. There was a significant increase in body weight gain in mice fed a high fat diet (HFD) or HFD with fish oil (HFD-FO), but not in mice fed a normal diet (ND). Although there was no significant difference between body weight gain and plasma insulin levels in the HFD and HFD-FO mice, the intake of HFD-FO prevented glucose intolerance and peripheral insulin resistance induced by HFD. In addition, macrophage infiltration and cytokine levels in white adipose tissue (WAT) in HFD-FO mice were decreased, compared with HFD mice. There were no significant differences between lipophagy related proteins and their mRNA levels in the HFD-FO and HFD groups. These results suggest that supplementation with fish oil might be beneficial in preventing insulin resistance caused by a high fat diet through an anti-inflammatory effect, but not lipophagy activation.