Additive beneficial effects of aerobic training and royal jelly on hippocampal inflammation and function in experimental autoimmune encephalomyelitis rats

Abstract

Background: Although the beneficial role of training and the use of some antioxidants in physiological and psychological disorders in autoimmune diseases has been reported, the simultaneous effect of aerobic training (AT) and royal jelly (RJ) with different doses is not well understood. The present study aimed to investigate the impact of AT and RJ on inflammatory factors in the hippocampus, as well as depression and anxiety in the experimental autoimmune encephalomyelitis (EAE).

Methods: Sprague-Dawley rats with EAE were assigned to seven groups: (1) EAE without any other intervention (EAE); (2) sham, receiving normal saline (Sh); (3) 50 mg/kg RJ (RJ50); (4) 100 mg/kg RJ (RJ100); (5) AT; (6) AT + RJ50; and (7) AT + RJ100. In addition, a healthy control group was assessed.

Results: EAE significantly increased interleukin 17 (IL-17), transforming growth factor-β (TGF-β) gene expression and immobilization time as well as anxiety and depression indices, and significantly decreased interleukin 10 (IL-10), compared to the control group. AT decreased significantly IL-17, TGF-β gene expression and immobilization time as well as anxiety and depression indices, while it significantly increased IL-10, compared to the EAE group. RJ50 and RJ100 decreased significantly IL-17, IL-23 gene expression, anxiety and depression indices, and significantly increased IL-10 compared to the EAE group. AT + RJ50 and AT + RJ100 significantly decreased IL-17, IL-23, and TGF-β and as well as anxiety and depression indices while significantly increasing IL-10 compared to the EAE group. The effects of AT + RJ100 on significant decreasing IL-17, IL-23, anxiety and depression and increasing TGF-β, IL-10 were more favorable than RJ50.

Conclusion: AT and RJ improved inflammatory and regulatory factors of autoimmunity and reduced anxiety and depression. The RJ combined with AT induced additive effects while using RJ100 was more favorable than RJ50.

Keywords: Aerobic training; Anxiety; Depression; Inflammation; Multiple sclerosis; Royal jelly.