The effect of resistance trainings along with Royal jelly supplementation on gene expression of nerve growth factor and tyrosine kinase A receptor in the hippocampal tissue of Alzheimer’s male rats

Although exercise training and antioxidants improve brain health, interactive effect of resistance training and Royal jelly has not yet been well established. Therefore, the aim of the current study was to investigate the effect of resistance training along with Royal jelly supplementation on hippocampal gene expression of nerve growth factor (NGF) and tyrosine kinase A (TrkA) receptor in rat model of Alzheimer’s disease.

In this experimental study, 42 male Sprague-Dawley rats were injected by Trimethyltin (8 mg/kg/body weight). Then, the rats were randomly divided into 7 equal groups including control, resistance training, resistance training+100 mg/kg Royal jelly supplementation, resistance training+200 mg/kg Royal jelly supplementation, 100 mg/kg Royal jelly supplementation, 200 mg/kg Royal jelly supplementation and sham groups. The resistance training protocol was performed for 8 weeks, three sessions per week at intensity to 30-100% of their body weight. Gene expression was assessed using Real-Time PCR and all primers were designed by Allele IDv7.8 software. Data were analyzed using two-way analysis of variance and Bonferroni post hoc tests at the p<0.05.

The resistance training induced a significant increase in NGF expression (p= 0.001). Moreover, 100 and 200 mg/kg Royal jelly supplementation, resistance training+100 and 200 mg/kg Royal jelly supplementation resulted in a significant increases in expression of NGF and TrkA receptor (p=0.001). In addition, the effect of royal jelly supplementation on NGF and TrkA receptor expression was dependent on its dosage, where the dose of 200 mg/kg was significantly higher than the dose of 100 mg/kg (p=0.001).

Both resistance training and Royal jelly supplementation, alone and synergistically, can increase neurotrophins expression in the hippocampus of Alzheimer’s rats; however higher dose of Royal jelly supplementation may induce more improvement.