Adipose tissue miRNA level variation through conjugated linoleic acid supplementation in diet-induced obese rats

Conjugated linoleic acid (CLA), which is an octadecadienoic acid isomer, is believed to play different positive physiological roles, such as lowering body fat. Due to some reported side effects of CLA, like lipodystrophy and impaired glucose metabolism, it is important to establish its safety by understanding detailed molecular mechanisms. One of these mechanisms may be the role of this dietary agent in modifying the function and activity of microRNAs (miRNAs).

The aim of the study was to investigate how adipocyte miR-27a and miR-143 expression may be influenced by CLA in obese rats.

In this study, 24 male Wistar rats were randomly divided into normal-fat diet (NFD) and high-fat diet (HFD) groups. After 8 weeks, the rats were weighed and half of the diet-induced obese rats were randomly selected to receive 500 mg CLA per 1 kg body weight for 4 weeks. At the end of this period, epididymal fat was isolated to investigate the expression level of miRNAs by real-time polymerase chain reaction (RT-PCR).

After 12 weeks, the obese rats in the HFD group, compared with rats in the NFD group, demonstrated a significant decrease in the expression of miR-27a (p < 0.05) and a significant increase in the expression of miR-143 (p < 0.05). In the group which had received CLA for a 4-week period, these events were reversed. Moreover, the rats in this group gained less weight than other rats in HFD groups, although the difference was not statistically significant.

In conclusion, this study demonstrated that CLA, as an anti-obesity agent, may minimize abnormal changes in miRNA expression in obesity. This suggests a new pathway for weight loss; however, further studies are needed.