Abstract TP115: Nrf2 Plays an Essential Role in Long-Term Neuroprotection of Ginseng in Permanent Cerebral Ischemia

Abstract

Introduction: Cerebral ischemia is a devastating disease with a high incidence of death and disability; however, effective therapeutics remain limited. The transcriptional factor Nrf2 has been shown to play a pivotal role in the endogenous defense against brain oxidative stress and inflammation; therefore, it represents a promising target for stroke intervention. The natural potential Nrf2-inducer ginseng, extracted from the root of Panax ginseng C.A.Meyer, has been widely used in East Asia for thousands of years, exhibiting potent anti-inflammatory and antioxidative properties. However, the long-term effects of Nrf2 and the standardized Korean red ginseng extract (ginseng) on permanent cerebral ischemic damage have not yet been reported. Methods: Wildtype (WT) and Nrf2 –/– adult mice were treated with either vehicle (water) or ginseng for 7 days and subjected to the permanent distal middle cerebral artery occlusion (pdMCAO). The infarct volume, the reactive astrogliosis and microgliosis, and water regulatory protein aquaporin 4 (AQP4) were examined 28 days after the initiation of stroke. Data acquisition and analyses were performed by an observer blinded to the treatment. Results: When compared with the WT matched controls, the Nrf2 disruption significantly enlarged the infarct volume by 40.4±10.1% (n=7 per group; p<0.05), increased levels of reactive gliosis and AQP4 protein after pdMCAO. Interestingly, ginseng significantly reduced the infarct volume and attenuated the reactive gliosis and AQP4 in the ischemic WT mice (47.3±6.9%, n=12; p<0.01), but not in the Nrf2 -/- mice (25.5±5.6%, n=11; p=0.241). Conclusion: Nrf2 plays an important role in the long-term recovery of permanent cerebral ischemic damage and neuroprotection of ginseng.