Puerarin protects against damage to spatial learning and memory ability in mice with chronic alcohol poisoning

We evaluated the effect of puerarin on spatial learning and memory ability of mice with chronic alcohol poisoning. A total of 30 male C57BL/6 mice were randomly divided into model, puerarin, and control groups (n=10 each). The model group received 60% (v/v) ethanol by intragastric administration followed by intraperitoneal injection of normal saline 30 min later. The puerarin group received intragastric 60% ethanol followed by intraperitoneal puerarin 30 min later, and the control group received intragastric saline followed by intraperitoneal saline. Six weeks after treatment, the Morris water maze and Tru Scan behavioral tests and immunofluorescence staining of cerebral cortex and hippocampal neurons (by Neu-N) and microglia (by Ib1) were conducted. Glutamic acid (Glu) and gamma amino butyric acid (GABA) in the cortex and hippocampus were assayed by high-performance liquid chromatography (HPLC), and tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta were determined by ELISA. Compared with mice in the control group, escape latency and distance were prolonged, and spontaneous movement distance was shortened (P < 0.05) by puerarin. The number of microglia was increased in both the cortex and hippocampal dentate gyrus (P < 0.01), and neurons were reduced only in the hippocampal dentate gyrus (P < 0.01) in puerarin-treated mice. In the model group, Glu and GABA levels decreased (P < 0.05), and Glu/GABA, TNF-alpha, and IL-1 beta increased (P<0.01) with puerarin treatment, returning to near normal levels. In conclusion, puerarin protected against the effects of chronic alcohol poisoning on spatial learning and memory ability primarily because of anti-inflammatory activity and regulation of the balance of Glu and GABA.