The Effect of Simultaneous Administration of Nanoliposomal Ursolic Acid Supplement along with Physical Activity in an Enriched Environment on the Expression of MOG, PLP, MBP and MAG Genes in Cerebellar Tissue of Aged Rats

Background and Purpose: Demyelination, axonal damage and loss of neurons with increasing age and advancing aging, which leads to decreased cognitive and motor performance and neurological diseases, is one of the concerns of today's societies due to the global increase in the population of elderly people. Not only does exercise improve overall brain health, it also acts as a powerful anti-aging treatment with minimal side effects. Also, ursolic acid with its anti-inflammatory properties prevents brain damage and reduces cognitive defects. Therefore, the aim of this study is to investigate the effect of simultaneous administration of ursolic acid supplement along with physical activity in an enriched environment on the expression of genes involved in myelination including myelin oligodendrocyte glycoprotein (MOG), myelin proteolipid protein (PLP), myelin basic protein (MBP) and Myelin-associated glycoprotein (MAG) in aged rats.
Materials and Methods: In this experimental study, 12 male Wistar rats, aged 16-20 months, were divided into four equal groups including: 1- old control + solvent, 2- old + supplement, 3- old + exercise and 4- old + supplement + exercise. Physical activity for 4 weeks, 5 sessions per week and each session was 30 minutes, which included voluntary exercise in an enriched environment (a metal cage larger than a standard cage with structures for the animal to climb, opportunities for shelter (houses, PVC pipes, cardboard tunnels), chews, spinning wheel and a set of 14 different non-chewable plastic objects). Nanoliposomal ursolic acid supplement gavage at the rate of 250 mg/kg body weight was performed on an empty stomach and according to training days. The expression of MOG, PLP, MBP and MAG genes in cerebellar tissue was done by Real-Time PCR method. The resulting data were analyzed using two-factor analysis of variance and Bonferroni's post hoc test at a significance level of P≤0.05.
Results: The simultaneous administration of ursolic acid and physical activity caused a significant increase in the expression of all studied genes compared to the other three groups. Voluntary physical activity and ursolic supplementation each alone led to a significant increase in the expression of MOG, PLP and MAG genes compared to the old control group.
Conclusion: According to the research findings, the simultaneous administration of ursolic acid supplement and voluntary and regular physical activities in old age, by stimulating myelination, may reduce axonal damage, neuronal destruction and age-related cognitive function decline to some extent. However, due to the limited research in this field, more investigations are needed in human societies.