The effects of resistance training, testosterone and palm (Phoenix dactylifera L.) pollen extract on the expression of FNDC5 and IGF1 genes in brown adipose tissue in male rats

The use of testosterone enanthate is popular among athletes, especially resistance sports. Considering the side effects of using testosterone enanthate, it seems necessary to find alternative methods. The present study compares the independent and interactive effects of resistance training, testosterone and palm pollen extract on the expression of FNDC5 and IGF1 genes in brown adipose tissue in male rats.

In this experimental study, 36 male rats were randomly assigned into 6 groups: control, resistance training, palm pollen extract, testosterone enanthate, palm pollen extract + resistance training and testosterone enanthate + resistance training. The resistance training program was implemented for 4 weeks (5 days per week). On training days, palm pollen extract gavage (100 mg/kg) and testosterone injection (2 mg/kg) were performed. 48 hours after the last intervention, rats were sacrificed, brown adipose tissue was collected and sent to the laboratory, and the expression of FNDC5 and IGF1 genes was measured by real-time PCR.

In rats, resistance training increased the expression of FNDC5 and IGF1 genes in brown adipose tissue (P=0.001). Testosterone also increased the expression of FNDC5 gene in brown adipose tissue (P=0.013). However, palm pollen extract had no significant effect on the expression of FNDC5 and IGF1 genes in brown adipose tissue. Also, no significant synergistic effect was found between research variables (P>0.05).

Based on the present findings, both resistance training and testosterone significantly increased the expression of FNDC5 gene in brown adipose tissue in rats, but had no significant effect on IGF1. Palm pollen extract had no significant effect on the expression of FNDC5 and IGF1 genes in brown adipose tissue in rats.