Neurotrophic Effects of Swimming and Crocin Consumption on the Rats with Obesity Induced by a High-fat Diet

Introduction: Obesity is a multifactorial physical disorder. Regular physical exercise and crocin consumption have been reported to have beneficial effects on obesity. The present study aimed to investigate the effects of eight weeks of swimming training with crocin consumption on the neurotrophic factors in the cardiac tissues of obese rats. Methods: This experimental study was conducted on 28 obese Sprague-Dawley rats (fat: 24 g, protein: 24 g, carbohydrates: 41 g/100 g), which were selected randomly and divided into five groups of seven, including: control (normal saline), swimming training, crocin consumption, and swimming with crocin consumption. Groups two and four performed swimming training for eight weeks (three sessions per week, each session: 30-60 minutes). Groups three and four were intraperitoneally administered with crocin on a daily basis (25 mg/kg). Results: Eight weeks of swimming and swimming with crocin consumption increased the expression of brain-derived neurotrophic factor (BDNF) in the cardiac tissues of the obese rats (P≤0.05). In addition, crocin consumption significantly increased BDNF and nerve growth factor (NGF) in the cardiac tissues of the obese rats (P≤0.05). However, no significant differences were observed in the gene expression levels of BDNF and NGF in the cardiac tissues of the animals with swimming and crocin consumption compared to the crocin consumption group (P≥0.05). Conclusion: According to the results, swimming alone, swimming with crocin consumption, and crocin consumption alone had similar effects on the increased level of BDNF in the cardiac tissues of obese rats. Furthermore, crocin consumption could significantly increase the expression of NGF in the cardiac tissues of obese rats.