(-)-Epigallocatechin gallate protects against cerebral ischemia-induced oxidative stress via Nrf2/ARE signaling.

Abstract

(-)-Epigallocatechin gallate (EGCG) has recently been shown to exert neuroprotection in a variety of neurological diseases; however, its role and the underlying mechanisms in cerebral ischemic injury are not fully understood. This study was conducted to investigate the potential neuroprotective effects of EGCG and the possible role of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway in the putative neuroprotection against experimental stroke in rats. The results revealed that EGCG exhibit significant neuroprotection, as evidenced by reduced infarction size and the decrease in transferase dUTP nick end labeling-positive neurons. Furthermore, EGCG also enhanced levels of Nrf2 and its downstream ARE pathway genes such as heme oxygenase-1, glutamate-cysteine ligase modulatory subunit and glutamate-cysteine ligase regulatory subunit, as compared to control groups. In accordance with its induction of Nrf2 activation, EGCG exerted a robust attenuation of reactive oxygen species generation and an increase in glutathione content in ischemic cortex. Taken together, these results demonstrated that EGCG exerted significant antioxidant and neuroprotective effects following focal cerebral ischemia, possibly through the activation of the Nrf2/ARE signaling pathway.