Terminalia chebula extracts ameliorate methamphetamine-induced memory deficits via activating the ERK and Nrf2 pathway

As a psychoactive substance abused worldwide, methamphetamine (METH) abuse leads to multiple neurodegenerative symptoms including memory deficits. Terminalia chebula retzius extracts (TREs) isolated by our lab have great antioxidant activity and its effect on METH-induced memory deficits has not been investigated yet. The present study was designed to investigate the protective effect of TREs on METH induced cell apoptosis in vitro and memory deficits in vivo. The results showed that TREs treatment attenuated free radical release and improved cell survival of primary hippocampal neurons after METH injury. In the Morris water maze task, TREs treatment reversed METH-induced learning and memory deficits in acquisition and retention. Moreover, TREs reduced oxidative stress in the serum and hippocampus of mice. Additionally, extracellular regulated protein kinases (ERK1/2) pathway and the nuclear factor E2-related factor 2 (Nrf2) pathway were inactivated after METH treatment, and were significantly activated after TREs pretreatment. These findings suggest that TREs may exert potent neuroprotective effect via activation of both ERK and Nrf2 pathways, thus providing a basis for its potential use for ameliorating memory deficits induced by METH.