The Effects of Royal Jelly and Tocotrienol Rich Fraction Along with Calorie Restriction Diet on White Fat Browning and Brown Adipocytes Activation in Obese Rats

Abstract

Background: Obesity is a public health problem across the world. Development of beige adipocytes in white adipose tissue (WAT) and activation of brown adipose tissue (BAT) can support obesity management. We aimed to investigate the effects of royal jelly (RJ) and tocotrienol-rich fraction (TRF) along with calorie restriction diet (CRD) on the genes involved in beige fat formation and BAT activation.Methods: Fifty 3-week-old male Wistar rats were fed high-fat diet (HFD) for 17 weeks. When obesity was induced, they were randomly divided into 5 groups (n=10/group): HFD, CRD, RJ+CRD, TRF+CRD, RJ+TRF+CRD for an additional 8 weeks. Finally, body weight was measured. Moreover, WAT and BAT were dissected for assessing the expression of major genes involved in adipose thermogenesis and histological changes evaluation. Results: At the end of the intervention, weight significantly decreased in RJ and RJ+TRF groups relative to the CRD group (p<0.05). RJ remarkably increased the expression of uncoupling protein 1 (UCP1) by 5.81 and 4.99 times more than CRD alone in WAT and BAT respectively (p<0.001). Expression of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1-α), peroxisome proliferator-activated receptor-α (PPAR-α) and Sirtuin1 (SIRT1) was significantly increased in WAT and BAT of rats receiving RJ and RJ+TRF. Peroxisome proliferator-activated receptor-γ (PPAR-Ƴ) expression was not noticeably changed in assessed adipose tissues. Brown-like adipocytes in WAT and denser adipocytes in BAT were obvious in RJ and RJ+TRF groups. However, the effect of TRF on studied genes was not noticeable. Conclusion: RJ+CRD improved markers of adipose thermogenesis and induced anti-obesity effects more than CRD alone did. Furthermore, RJ remodeled adipose tissue and could be considered as a new therapeutic target.