Abstract
Chronic stress has been recognized to induce the alterations of neuronal and glial cells in the hippocampus, and is thus implicated in cognitive dysfunction. There is increasing evidence to indicate that natural compounds capable of exerting neuroprotective and antioxidant activities, may function as potential therapeutic agents for cognitive impairment. The present study examined the neuroprotective effects of pinostrobin from Boesenbergia rotunda (L.) against chronic restraint stress (CRS)-induced cognitive impairment associated with the alterations of oxidative stress, neuronal density and glial fibrillary acidic protein (GFAP) of astrocytes in the hippocampus. For this purpose, male Wistar rats were administered once daily with pinostrobin (20 and 40 mg/kg, per os) prior to exposure to CRS (6 h/day) for 21 days. The cognitive behaviors, the concentration of malondialdehyde, and the activities of superoxide dismutase and catalase were determined. Histologically, the alterations in astrocytic GFAP and excitatory amino acid transporter 2 (EAAT2) in the hippocampus were examined. The results revealed that pinostrobin potentially attenuated cognitive impairment in the Y-maze and in novel object recognition tests, with a reduction in oxidative stress. Furthermore, pinostrobin effectively increased neuronal density, as well as the immunoreactivities of GFAP and EAAT2 in the hippocampus. Taken together, these findings indicate that treatment with pinostrobin alleviates chronic stress-induced cognitive impairment by exerting antioxidant effects, reducing neuronal cell damage, and improving the function of astrocytic GFAP and EAAT2. Thus, pinostrobin may have potential for use as a neuroprotective agent to protect against chronic stress-induced brain dysfunction and cognitive deficits.