The effect of eight weeks of high-intensity interval training with spirulina supplementation on apoptotic markers in the hippocampal tissue of high-fat diet-induced obese rats

Background: Obesity leads to neuronal apoptosis and cognitive impairment by increasing inflammation and oxidative stress. Although the beneficial role of exercise and antioxidant supplements have been reported separately, their interactive effect on neuronal apoptosis in obesity is still not well known. Therefore, this study aimed to investigate the effect of eight weeks of HIIT with Sp supplementation on apoptotic markers in the hippocampal tissue of high-fat diet-(HFD) induced obese rats. Methods: In this experimental study, 24 obese male Sprague-Dawley rats (60% fat, 20% protein, and 20% carbohydrates) were randomly divided into four groups of six rats, including 1) HFD, 2) HFD+Sp, 3) HFD+HIIT, and 4) HFD+HIIT+Sp. Also, six healthy rats were selected as the HC group to investigate the effects of HFD on research variables. Subsequently, HIIT was performed for eight weeks, three sessions per week with an intensity of 80-110% of maximum running speed and 2-8 high-intensity intervals. Also, Sp supplement was taken orally during this period with a dose of 100 mg/kg/day. Bax and BCL-2 levels were measured with qRT-PCR method. One-way analysis of variance and Tukey's post-hoc tests were used for statistical analysis of data (p ≤0.05). Results: In the HFD+HIIT and HFD+HIIT+Sp groups, Bax levels and Bax/BCL-2 ratio were lower and BCL-2 levels were higher than the HFD group (p=0.001). In the HFD+Sp group, BCL-2 levels were higher and Bax/BCL-2 ratios were lower than HFD group (p=0.008). Also, in the HFD+HIIT and HFD+HIIT+Sp groups, Bax levels and Bax/BCL ratio were lower and BCL-2 levels were higher than HFD+Sp group (p≤0.05). In addition, in the HFD+HIIT+Sp group, Bax levels were lower and BCL-2 levels were higher than in the HFD+HIIT group (p≤0.05). Conclusion: It seems that although HIIT and Sp supplement separately have an anti-apoptotic effect, their interactive effect on inhibiting neuronal apoptosis in brain tissue in obesity conditions is more obvious than the effect of each one alone.