Huangqi Gegen decoction ameliorates alcohol-induced cognitive dysfunction via attenuating oxidative stress and enhancing blood-brain barrier integrity in rats through the Keap1-Nrf2/HO-1 signaling pathway

Chronic alcohol abuse causes cognitive deficits. Huangqi Gegen Decoction (HGD), a traditional Chinese herbal formula comprising Huangqi and Gegen, has been documented for its therapeutic efficacy in the treatment of alcoholic liver injury. However, its potential neuroprotective effects against alcohol-induced brain injury remain unexplored. This study aims to evaluate the neuroprotection of HGD on alcohol-induced cognitive dysfunction and the associated mechanism.

Wistar rats were orally administered 50% ethanol for 10 weeks, followed by treatment with HGD at doses of 16, 32, or 64 mg/kg/day for an additional 6 weeks. The spatial learning and memory abilities of rats were assessed through the Morris Water Maze experiment. The pathological condition in the hippocampus was assessed using H&E and Nissl staining. Tight junction proteins, oxidative stress, and inflammation cytokines were measured by IF, ELISA, PCR, and western blot. The mRNA and protein expression of Keap1, Nrf-2, HO-1, and NQO-1 were tested by PCR and western blot.

Results showed that HGD effectively mitigated cognitive dysfunction and pathological changes in alcohol-induced rats while enhancing the expression of ZO-1, Occludin, and Claudin-5. Furthermore, HGD effectively mitigated oxidative stress by reducing levels of ROS and MDA, while elevating levels of SOD, CAT, and GSH-PX in brain tissue. Moreover, HGD significantly suppressed microglial activation and down-regulated expressions of IL-1β, IL-6, and TNF-α. Mechanistically, HGD remarkably up-regulated the expression of Nrf-2, HO-1, and NQO-1 while down-regulating Keap1 expression.

These findings suggest that HGD may be a promising therapeutic agent for alleviating alcohol-induced cognitive dysfunction.