The Effect of Eight Weeks of Endurance Training with Royal Jelly and Propolis on Angiotensin-2 and Endothelin-1 in Heart Tissue of Ovariectomized Rats with Diabetes

 Patients who are diagnosed with diabetes are very susceptible to cardiovascular complications and cardiovascular diseases are considered the most important causes of death in these patients. The prevalence of cardiovascular disease in patients with type 2 diabetes is about 2-4 times that of non-diabetic people. Diabetic patients face endothelial damage and functional disorders. These disorders include functional changes of the endothelium, such as disorders in the regulation of vascular expansion and contraction and increased inflammatory activity, which is related to cardiovascular disease. Insulin is known as a direct and effective agent in the vascular endothelium, which affects the modulation of vascular tone. It exerts its effects on vascular tone through two pathways of nitric oxide release and endothelin-1. Endothelin-1 is a strong vasoconstrictor that is secreted by vascular endothelial cells. This substance is known as the strongest vasoconstrictor and its contraction effect is ten times more than angiotensin-2, vasopressin, and neuropeptide Y. Angiotensin II is the end product of the reaction catalyzed by the angiotensin-converting enzyme, a vascular activating peptide that causes the proliferation of smooth muscle cells of the vessel walls, Myocytes hypertrophy and the release of platelet-derived growth factor. All of these play a role in the occurrence of vascular disorders. To eliminate the undesirable redox state caused by estrogen deficiency, specific measures have been investigated, the most effective of which is hormone therapy; But at the same time, it increases the risk of coronary heart disease, pulmonary embolism, and breast, uterine, and ovarian cancer in consumers. Changing lifestyles and exercising can be effective in preventing menopause syndrome (8). Also, numerous types of research are conducted today to evaluate the effectiveness of compounds with antioxidant properties against cell damage caused by oxidant agents. Some research has shown that royal jelly reduces the complications of diabetes. Royal jelly can be considered a therapeutic method to prevent insulin resistance, which is associated with high blood pressure in patients with diabetes. Propolis is also a resinous substance that is collected by bees from different types of tree buds and is used to cover the parts of the hive and to seal the cracks and crevices of the pack. According to the issues raised and also considering that in the reviewed studies, no study was found that examined the effect of endurance training and royal jelly on menopause and its complications, so the present study seeks to find the answer to this question. The question is whether eight weeks of endurance training with royal jelly has a significant effect on the markers of angiotensin-2 and endothelin-1 in the heart tissue of Ovariectomized rats suffering from diabetes or not.

In this experimental study, 40 Ovariectomized rats with diabetes (40 mg/kg Streptozotocin) were randomly divided into (1) OVXD, (2) Sham, and (2) groups. 3) RJ, (4) Pr, (5) ET, (6) ET+RJ, (7) ET+Pr, and (8) ET+RJ+Pr were divided. To investigate the effect of Ovariectomy and diabetes, 6 rats were considered as a healthy control group. Endurance training groups ran for eight weeks, three sessions a week and each session was 60 minutes with an intensity of 55-75% VO2 max on the treadmill, especially for rats. The royal jelly and Propolis consumption groups received 100 mg/kg daily supplements as a peritoneal injections. To analyze the data, a one-way analysis of variance with Tukey's post hoc test was used.

The results showed that RJ and Pr decreased angiotensin-2 significantly less than the OVXD group (P≥0.05). In the ET+RJ group, the values of angiotensin-2 and endothelin-1 were significantly lower than in the OVXD group (P≥0.05). Also, in the ET+Pr group, the values of angiotensin-2 and endothelin-1 were significantly lower than in the OVXD group (P≥0.05). In the ET+RJ+Pr group, the values of angiotensin-2 and endothelin-1 were significantly lower than in the OVXD group (P≥0.05). The effect of exercise + royal jelly and also exercise + Propolis on the increase of angiotensin-2 and endothelin-1 was more favorable than the effect of ET, RJ, and Pr (P≥0.05).

It seems that endurance exercise and royal jelly supplement alone have improving effects on the condition of heart tissue in diabetic conditions; but these two interventions, combined, complement each other's effect to improve the risk factors of cardiovascular diseases in menopause and diabetes. The results of the present study showed that RJ values of MDA and angiotensin-2 were significantly lower than the OVXD group. Therefore, it seems that the use of antioxidant supplements such as royal jelly and Propolis can be effective in improving cardiovascular function through antioxidant pathways and reducing oxidative stress. Due to the increase of some antioxidants and the reduction of oxidative stress following sports training; it is suggested to use sports exercises similar to the present study to prevent the risk of a heart attack in menopause and diabetes. According to the interactive effects of endurance training with royal jelly on antioxidants, reducing oxidative stress is suggested in future studies to modulate oxidant-antioxidant and also reduce cardiovascular risk factors from the combination of these antioxidants along with sports activities.