Dietary 7,10-dihydroxy-8(E)-octadecenoic acid reduces fat accumulation and prevents hyperglycemia and hyperlipidemia in diabetic/obese KK-Ay mice

Abstract

7,10-Dihydroxy-8(E)-octadecenoic acid (DOD) is a dihydroxy fatty acid produced by Pseudomonas aeruginosa PR3 from oleic acid. Present study investigated preventive effects of dietary DOD on obesity, hyperlipidemia and hyperglycemia in diabetic/obese KK-A^y mice. After one week of acclimation, mice (5-week-old) were divided three groups fed with AIN-93G-based high fat diet (20% fat, w/w) as follows; Control group: 3% soybean oil + 17% lard, DOD 1% group: 3% soybean oil + 16% lard +1% DOD, DOD 2% group: 3% soybean oil + 15% lard + 2% DOD. Four weeks feeding with 1% and 2% DOD diets suppressed body weight gain and visceral fat accumulation, and improved blood glucose and serum lipids levels as well as hepatic lipid accumulation compared to control group. RT-PCR analysis revealed no changes were observed in mRNA of adiponectin (Adipoq) and proinflammatory TNF-α (Tnfa) and MCP-1 (Ccl2), but a decreasing trend in leptin mRNA expression in mesenteric white adipose tissue (WAT), suggesting that suppressed fat accumulation by DOD contribute to prevention of over production of leptin. We also observed a reduction of mRNA expression of hepatic insulin-target gluconeogenic enzymes such as PEPCK and G6Pase and the transcription factor sterol regulatory element-binding protein-1. These results showed that dietary DOD is effective to improve glucose and lipid metabolism in KK-A^y mice. The present study provides new insights showing potential use of dihydroxy fatty acids as functional lipids.