The Intervention Effect Of Pleurotus Eryngii Polypeptides On Lead Induced Brain Injury In Rats

[Objective] In this study, we developed the influence of Pleurotus eryngii polypeptides on the hippocampus and cortex of rats exposed to lead from the molecular level, and then to explore the nutrition intervention effect of Pleurotus eryngii polypeptides on lead induced brain injury which provide theoretical basis for preventing harm of lead.[Methods] 30 healthy male rats(60 ± 5 g) were randomly divided into three groups:the normal control group (normal diet+ distilled water),the model group (normal diet+0.2% lead acetate water) and the test group (normal diet+2% Pleurotus eryngii polypeptides+0.2% lead acetate water). After 60 days of continuous feeding, the hippocampus and cortex were collected. Then we calculated the brain index and detected the calcium, lead, iron, zinc, copper, manganese, magnesium content. The hippocampus and cortex histopathological changes were observed by HE stain. The expression of levels of Camk2a, Homer1 and ERK2 were studied by real-time RT-PCR.[Results] (1) Compared with the control group, the brain index of rats in lead exposed group significantly decreased P< 0.05). The brain index in test group increased compared withthe model group, and there was significant difference. (P< 0.05).(2) We observed that the content of calcium, zinc, iron, magnesium significantly decreased and lead levels significantly elevated in lead exposed group compared with the control group (P< 0.05). The copper, manganese content of rats in lead exposed group elevated, but the changes were not significant. Compared withthe model group, the content of lead in the test group reduced significantly, and the iron, magnesium, calcium, zinc content were significantly or extremely significantly increased in the brain tissue (P< 0.05 or P< 0.01), while the copper, manganese content did not obviously change.(3) In the Model group, we observed that the number of hippocampus and cortex cells declined, the cell layer thinned, the cell gap increased, the shape is relatively simple and the nucleolus is not clear. Compared with the Model group, the number ofhippocampus and cortex cells increased, the volume expanded, the cell gap narrowed, and there weremore clear nucleolus, and intact cell structure.(4) Compared with the control group, the Camk2a, Homer 1, ERK2 mRNA expression levels of the hippocampus and cortex in lead exposed group significantly reduced (P< 0.01). The Camk2a, Homerl, ERK2 mRNA expression levels of the hippocampus and cortex in test group significantly increased compared withthe model group (P< 0.05, P< 0.01).[Conclusion] Pleurotus eryngii polypeptides can regulate the divalent metal elements unbalance in the brain tissue of lead exposed rats, alleviate the damage effects of lead on hippocampaland cortex. It can also influence the Camk2a, Homerl, ERK2 mRNA expression in the hippocampus and cortex to intervent the brain injury which caused by lead.