Razi Journal of Medical Sciences

Background & Aims: Parkinson’s disease is a debilitating condition commonly affecting individuals over 50 and ranks as the second most prevalent neurodegenerative disorder worldwide, following Alzheimer’s (1). It impacts nearly all aspects of daily life, with patients frequently experiencing difficulties in walking, standing up, fatigue, increased effort required for routine tasks, and non-motor symptoms including impaired smell, memory issues, and digestive problems (2). Brain-derived neurotrophic factor (BDNF) is a neuroprotective protein that shields dopaminergic neurons from degradation. It plays a critical role in the development and maintenance of the central and peripheral nervous systems, synaptic plasticity, neuronal proliferation and survival, as well as learning, memory, and mood regulation (12).
Alpha-synuclein is a highly conserved protein abundantly present in the central nervous system (CNS) (14). Normally, it exists in a folded, unstructured random coil conformation within the cell cytoplasm, lacking regular secondary structures. Its conformation changes upon interaction with lipid membranes (16).
The negative personal and social impact of Parkinson’s, the recognized importance of physical activity, the beneficial properties of quercetin, the lack of consensus among researchers on the optimal training method alone or combined with medicinal plants, and the scarcity of studies on interval training combined with quercetin in Parkinsonian model this study aims to determine whether interval aerobic exercise and quercetin supplementation influence BDNF and alpha-synuclein protein expression in the hippocampus of male Parkinsonian model rats.
Methods: The current research is experimental and applied. To do that, 28 male Wistar rats, 8-10 weeks old and weighing 180-200 grams, after 2 weeks of familiarization with the environment, were randomly divided into five groups of healthy rats, which were killed and operated at the end of the protocol, and training and did not use supplements (5 head healthy reference group), Parkinsonian rats that were killed and operated at the end of the protocol and did not exercise or take supplements (5 heads Parkinsonian control group), Parkinsonian rats that were killed and operated at the end of the protocol and only participated in interval aerobic exercise (Parkinson's exercise group: 6 subjects).
Parkinsonian rats that were killed and operated on at the end of the protocol and took only supplements (Parkinson's melatonin group: 6 heads) and Parkinsonian rats that were killed and operated on at the end of the protocol and participated in both interval aerobic exercise and supplementation ( Exercise group + Parkinson's supplement: 6 heads) were divided. Next, the training groups performed the aerobic training program according to the following protocol:
To perform the aerobic interval activity, rats were first introduced to the five-rail treadmill (Azma technique, made in Iran) for one week to reduce the stress of the new environment. Also, the intensity of the activity in the first two weeks of training started from 10 meters per minute for 15 minutes, then the duration of the activity reached 30 minutes. The incline of the treadmill was fixed at 5 degrees from the beginning to the end of the training period. For each training session, 5 minutes of warm-up at a speed of 5-10 m/min and the same amount of cool-down were considered. (30)
The protocol of aerobic training was for 12 weeks and 5 sessions per week. The details of the protocol, including speed, time and incline, were determined each week after performing the exercise capacity test and determining VO2peak. It should be noted that the supplement groups also consumed quercetin supplement for 12 weeks orally and daily at 100 mg/kg of body weight manufactured by Sigma Company in the form of water solution, at 8 to 10 in the morning. Finally, immediately after the last training session, all the rats were anesthetized using chloroform and the hippocampal tissue of their brains was removed to check the research variables. two-way analysis of variance and Tukey's follow-up were used for statistical analysis of the data.
Results: In order to explain the effect of exercise and crostinin supplementation on BDNF protein level in rats with Parkinson's disease, two-way analysis of variance test was used and the results showed that the interaction effect between exercise and supplementation on BDNF is not significant (F1=0.24). 655 and P=0.426) It was also found that the main effect of exercise on BDNF is not significant (F1,24=653.3 and P=0.068), but the main effect of croestin supplementation on BDNF is significant (F1,24 =5.093 and P=0.033). Considering the significance of the effect of the supplement, Bonferroni's post hoc test was used to compare the groups and the results showed that there is a significant difference between supplement use and non-supplement use.
Conclusion: The results showed that the interaction effect of exercise and supplementation and the main effect of exercise on BDNF are not significant. However, it was found that the main effect of croestin supplement on BDNF is significant. In this regard, researches have shown that the prescription of food programs that contain natural antioxidants (such as fruits, plants, legumes, oil seeds, whole grains and vegetables, as well as the consumption of foods processed with Natural antioxidants such as vitamin C and E, carotenoids and polyphenols) can provide a suitable antioxidant status and help prevent neurodegenerative and metabolic disorders. On the other hand, it has been found that BDNF is one of the most important neurotrophins that is widely distributed in the central nervous system and has a significant effect on memory and learning functions (36).
Conversely, quercetin a flavonol naturally present in many fruits, vegetables, leaves, and seeds is also available as a dietary supplement. This compound exhibits antioxidant, anticancer, antiviral, and anti-inflammatory properties. Additionally, quercetin combats free radicals and enhances nutrient flow within blood vessels (38). The observed effect of quercetin on BDNF in the current study likely stems from its antioxidant activity. Nevertheless, the study found that the combined effect of exercise and quercetin supplementation on BDNF in Parkinsonian rats was not significant. This lack of significance may be attributable to the heightened exercise-induced stress and the subsequent generation of reactive oxygen species (ROS) and free radicals.