Onjisaponin B prevents cognitive impairment in a rat model of D-galactose-induced aging

In this study, we investigated the potential effect of onjisaponin B (OB) on aging rats induced by D-gal (D-galactose). Sub-acute aging model was established in rats by the subcutaneous injection of D-gal (120 mg/kg) for 42 days, accompanied with OB (10, 20 mg/kg, p.o.) or normal saline intervention for 28 days since the 14th day after the beginning of D-gal stimulation. Morris water maze test and step-down passive avoidance test were conducted to evaluate the cognitive function of the rats. The superoxidase dismutase (SOD), malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase (GSH-px) contents in hippocampus were measured by according kits, respectively. And the hippocampus levels of inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were assayed by enzyme-linked immunosorbent assay (ELISA). Furthermore, the expressions of SOD1, MDA5, GSH, GSH-px, NF-кB pathway were present by western blot. It revealed that administration of OB was able to significantly attenuate the D-gal-induced changes in the hippocampus, ranging from cognitive capacity, oxidative stress to inflammation response. In a nutshell, our data provided evidence that OB could contribute to the restoration of cognitive ability by improving the antioxidant and anti-inflammatory capacity in D-gal induced aging rats.