Preventive effects of conjugated linoleic acid on obesity by improved physical activity in nescient basic helix-loop-helix 2 knockout mice during growth period

Abstract

The purpose of this study was to evaluate whether conjugated linoleic acid (CLA) exposure during the developmental period increases voluntary activity, which would influence obesity outcome later in life. The effects of dietary supplementation of 0.5% CLA in a high fat diet were evaluated in nescient basic helix-loop-helix 2 (Nhlh2) knock-out (N2KO) mice, which is a unique animal model representing inactivity-induced obesity in a pre-obese condition. Male wild type and N2KO mice were fed either control or CLA (0.5%) diet for 8 weeks. As expected, control diet fed N2KO animals showed greater body weight with decreased physical activity in the late stage of the experimental period compared with wild type control. Dietary CLA significantly decreased body weight and adipose depots in both wild type and N2KO mice, and the body weights of both genotypes fed CLA were similar during the experimental period. CLA exposure during the developmental period significantly improved the impairment of physical activity in N2KO mice, but the wild type did not show any effect of CLA. In both genotypes, CLA significantly reduced serum triglycerides levels and down-regulated the mRNA expressions of CCAAT/enhancer binding protein α (C/EBPα) and leptin in white adipose tissue. These findings suggest that early CLA exposure could prevent obesity with improved voluntary physical activity in N2KO mice.