Geniposide attenuates early brain injury by inhibiting oxidative stress and neurocyte apoptosis after subarachnoid hemorrhage in rats

Background Oxidative stress and neurocyte apoptosis are crucial pathophysiological process in early brain injury (EBI) after subarachnoid hemorrhage (SAH). Geniposide (GNP) has been reported to exert neuroprotective effects by reducing oxidative injury and neurocyte apoptosis. However, the effect of GNP has not been clarified in EBI after SAH. The study was performed to evaluate the neuroprotective effects and mechanisms of GNP in EBI after SAH. Methods and results A total of 60 male Wistar rats were randomly divided into five groups. The prechiasmatic cistern SAH model was used in this study. SAH grade was evaluated using a grading system. Neurological function was evaluated using the Garcia scores. Brain edema was measured by the wet-dry method. Blood-brain barrier (BBB) permeability was measured by the extravasation of Evans Blue (EB). The neurocyte apoptosis was observed using TUNEL assay. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD), as well as the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), hemeoxygenase-1 (HO-1), glutathione S-transferase (GST) and quinone oxidoreductase-1 (NQO-1) were performed. The results showed that GNP reduced brain edema, attenuated BBB permeability, inhibited neurocyte apoptosis and improved neurological function. Moreover, GNP also decreased the levels of ROS and MDA, elevated Nrf2 expression in the temporal cortex and up-regulated the expression of NQO-1, HO-1 and GST after SAH. Conclusions GNP could ameliorate oxidative stress and neurocyte apoptosis to exert neuroprotective effects by Nrf2 pathway.