Protective effects of vitamin D supplementation combined with exercise on depressive-like behaviors in chronic stress rats.

Abstract

OBJECTIVE: Depression is a common mental disorder with a severe impact on patients' physical and mental health. This study aimed to assess the protective effects of vitamin D supplementation combined with exercise on the depressive-like behaviors of chronic unpredictable mild stress (CUMS) rats. METHODS: Forty Sprague-Dawley rats were randomly divided into control, model, vitamin D, exercise, and combination (vitamin D + exercise) groups ( n  = 8). After treated for 4-week protocol of CUMS combined with solitary rearing, the vitamin D group was gavaged with 0.2 µg/kg vitamin D, the exercise group exercised at 20 rpm/min for 30 min, and the combination group was gavaged with 0.2 µg/kg vitamin D after 30 min exercise at 20 rpm/min, once a day during continued treating with 8-week protocol of CUMS. The behavior of rats was detected by the sucrose preference test, open field test, and elevated plus maze. Pathological changes in the hippocampus were observed by hematoxylin-eosin staining. The serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by ELISA. RESULTS: The results showed that the CUMS procedure successfully induced a depressive rat model. Vitamin D supplementation and exercise could increase sucrose preference, enhance locomotor activity and exploratory behavior, alleviate anxiety, protect hippocampal neurons, and reduce the expression levels of inflammatory factors. CONCLUSION: Vitamin D supplementation combined with exercise has improved the depressive behaviors and hippocampal neurons of rats than vitamin D or exercise intervention alone, probably by regulating the expression levels of inflammatory factors TNF-α and IL-6.