Protective effect of oleuropein on the brain tissue in D-Galactose-induced aging in rat model

Abstract

Background: Oleuropein (OLE) has the potential to reduce oxidative stress and inflammation. So, in the present investigation, we explored the protective effect of OLE on brain aging induced by d-galactose (D-Gal) in a rat model.

Methods and results: 40 Wister male adult rats were categorized into 5 groups. Group 1 received normal saline; group 2 was given 100 mg/kg of D-Gal intraperitoneally (IP). The rats in groups 3 to 5 were given D-Gal (100 mg/kg, IP) along with different doses of OLE (20, 40, and 80 mg/kg, respectively) orally. All administrations were performed daily for 8 weeks. 24 h after last treatment motor activity and memory impairment were evaluated. Then, the rats were euthanized and brain samples were collected for evaluating the levels of malondialdehyde (MDA), Brain-Derived Neurotrophic Factor (BDNF), protein carbonyl (PC), glutathione (GSH), glutathione peroxidase (GPX), catalase (CAT), Superoxide dismutase (SOD), Tumor necrosis factor alpha (TNF-α), interleukin 1 beta ( IL-1β), as well as Sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1) gene expression. The results showed that D-Gal significantly reduced motor activity and memory performance (P < 0.05). It also significantly reduced the GPX, CAT and SOD activities, GSH and BDNF levels as well as SIRT1 and PGC1 expression, and, significantly increased PC, MDA TNF-α and IL-1β levels in the brain tissue (P < 0.05). Administration of OLE restored all of the above parameters close to control group.

Conclusion: The findings demonstrated that OLE, through its antioxidant and anti-inflammatory properties, improved motor activity, memory impairment, and age-related neurological dysfunction.

Keywords: Brain tissue; D-galactose; Oleuropein; Oxidative stress.