Pollock oil supplementation modulates hyperlipidemia and ameliorates hepatic steatosis in mice fed a high-fat diet

• Main Authors: Hatanaka Akimasa, Takeo Jiro, Miyahara Hiroko, Yang Zhi-Hong, Katayama Masashi
• Format: Article
• Language: English
• Published: BMC 2011-10-01
• Series: Lipids in Health and Disease
• Subjects: Pollock oil; n-3 PUFA; MUFA; hyperlipidemia; hepatic steatosis; adipokines
• Online Access: http://www.lipidworld.com/content/10/1/189

<p>Abstract</p> <p>Background</p> <p>Hyperlipidemia associated with obesity is closely related to the development of atherosclerosis. Both n-3 polyunsaturated fatty acids (PUFAs) and long-chain monounsaturated fatty acids (MUFAs; i.e., C20:1 and C22:1 isomers) supplementation modulate risk factors for metabolic syndrome via multiple mechanisms, including the restoration of impaired lipid metabolism. We therefore examined the effects of pollock oil, which contains a considerable amount of n-3 PUFAs as well as long-chain MUFAs, on plasma hyperlipidemia and hepatic steatosis in diet-induced obese mice.</p> <p>Methods</p> <p>Male C57BL/6J mice (24-26 g) were divided into two groups (n = 10/group) and were fed a high-fat diet containing 32% lard (control group) or 17% lard plus 15% pollock oil (experimental group) for 6 weeks. For both groups, fat comprised 60% of the total caloric intake.</p> <p>Results</p> <p>Although body and liver masses for the two groups did not differ significantly, hepatic lipids concentrations (triglycerides and total cholesterols) were lower (<it>P </it>< 0.05) after pollock oil ingestion. After 2 weeks on the specified diets, plasma lipid levels (total cholesterol, LDL cholesterol, and triglycerides) significantly decreased (<it>P </it>< 0.05) in the experimental group compared with the control group, although plasma HDL cholesterol levels did not differ. At the end of 6 weeks, plasma adiponectin levels increased (<it>P </it>< 0.05), whereas plasma resistin and leptin levels decreased (<it>P </it>< 0.05) in the experimental mice. Increased levels of long-chain MUFAs and n-3 PUFAs in plasma, liver and adipose tissue by ingesting pollock oil were possibly correlated to these favorable changes. Expression of hepatic genes involved in cholesterol metabolism (<it>SREBP2</it>, <it>HMGCR</it>, and <it>ApoB</it>) and lipogenesis (<it>SREPB1c</it>, <it>SCD-1</it>, <it>FAS</it>, and <it>Acac</it>α) was suppressed in the experimental group, and may have favorably affected hyperlipidemia and hepatic steatosis induced by the high-fat diet.</p> <p>Conclusions</p> <p>We demonstrated that pollock oil supplementation effectively improved hyperlipidemia, attenuated hepatic steatosis, and downregulated the express of hepatic genes involved in cholesterol and lipid metabolism in mice with diet-induced obesity.</p>