The Effect of Resistance Training Along with Royal Jelly Supplementation on Expression of Nerve Growth Factor and Tyrosine Kinase A Receptor in the Hippocampal Tissue of Alzheimer's Rats

Introduction: Current study aimed to investigate the effects of resistance training (RT) along with royal jelly (RJ) supplementation on hippocampal expression of nerve growth factor (proNGF) and p75 receptor in a rat’s model of Alzheimer's disease.  Method: 42 male Sprague-Dawley rats were treated with Trimethyltin chloride (8 mg/kg). Then, the rats were randomly divided into seven equal groups control, RT, RT + supplementation of RJ 100 mg/kg (RT+RJ100), RT+supplementation of RJ200 (RT+RJ200), supplementation of RJ100, supplementation of RJ200, and sham group. Supplement groups received 100 and 200 mg/kg/day of RJ for eight weeks. The incremental RT protocol was performed for eight weeks, three weekly sessions at intensity according to 30-100% of body weight. Results: The RT protocol significantly increased proNGF expression compared to the control group. In addition, RJ100 and RJ200 resulted in a significant increase in the expression of proNGF and p75. Furthermore, the interaction effect of RT+RJ100 and RT+RJ200 induced a considerable increase in proNGF and p75 expression. Also, the impact of RJ on proNGF and p75 expression was dose-dependent, and the effect of the 200 mg/kg dose was significantly higher than the 100 mg/kg dose. Conclusion: Both RT protocol and RJ supplementation synergistically increase neurotrophin expression in the hippocampus of Alzheimer's rats. The effects of RJ in combination use are dose-dependent, with higher doses having higher effects on neurotrophin and receptor expression. In the case of using a single dose of RJ, a lower dose is more desirable.