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

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.

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.

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