Neuro-protective Effects Of Anthocyanins On Cerebral Ischemia Reperfusion Injury

The neurons death caused by cerebral ischemia can lead to death and injury. The main factor causing tissue damage is not ischemia itself, but the blood reperfusion. After reperfusion, the excessive free radicals and inflammatory factors would attack the cells in the reperfusion parts. How to reduce the death of nerve cells and promote the recovery of neurological function is becoming the focus of the study. Anthocyanin is a kind of flavonoid compounds. They have many physiological functions just like antioxidant, anti-inflammatory and so on but low toxicity.This study aimed to investigate the neuroprotection of anthocyanins on both mice and nerve cell of cerebral ischemia reperfusion injury and discuss the mechanism of action. The main research contents and conclusion are as follows.(l)We established complete cerebral ischemia reperfusion animal model by Kunming mice. After pretreating with anthocyanins(200mg/kg) for10days, we use Morris Water Maze to survey the effects of anthocyanins on cognitive ability of mice model. According to the results, we found that after ischemia for1h and reperfusion for24h, the model mice had a significantly cognitive decline while the model mice which pretreated with anthocyanins had higher cognitive ability than the model mice. The HE staining results showed that the neurons in model mice became thinner and nuclear chromatin layer gathered toward the center with the uneven distribution. The neurons treated with anthocyanins were much more full and tight. The TTC staining results showed that the infarcts were observed in both sides after surgery. The anthocyanins could reduce the infarction area in model mice.In order to study the roles of free radicals and oxidative damage, we detect the contents of MDA and SOD of cortex and hippocampal neurons in mice through biochemical methods. The results suggested that anthocyanins could reduce MDA content and increase SOD activity after cerebral ischemia injury. These showed that anthocyanins could reduce cerebral ischemia injury by removing free radical and anti oxidative stress.(2)We set up oxygen glucose deprivation/reoxygenation cell model to simulate pathological damage of cerebral ischemia reperfusion injury. The cell viability was measured by MTT and the influences of anthocyanins on BV2cell’s activation degree were measured by cell morphological observation. According to the results, after OGD/R for3h/1h, the activation occurred on BV2cell and the cell viability rise. After reoxygenation for12h, the cell viability decreased. Cell morphology observation showed that after OGD/R for3h/24h, the cell morphology of BV2cell had changed. The cell body became bigger, and the cell shape was from cone into amebocytes. The anthocyanins could inhibit this activative phenomenon. In the cerebral ischemia reperfusion injury, the activated microglia cells play a role of neurotoxicity by secreting the inflammatory factors. We detected the transcription activity of NF-κB and the secretion of TNF-a by biochemical methods. The results suggested that anthocyanins could reduce the expression of p65and the secretion level of TNF-a in damaged cells.(3)In order to study the effects of activated microglia in meurons, we built up the OGD/R cell model by BV2cell and prepared culture supernatants under different OGD/R conditions. After that, we use these supernatant to deal with PC12cell which had been induced by H2O2. The cell viability was measure by MTT. The results showed that the anthocyanins can relieve PC12cell through the oxidative stress injury induced by H2O2. The BV2supernatant of OGD for1h could reduce oxidative stress injury of PC12cell while the BV2supernatant of OGD/R for3/24h could aggravate the injury. After dealing with anthocyanins, the BV2supernatant of OGD/R for3/24h’s damage would decrease. These results suggested that the excessive activation of BV2cell can aggravate PC12cell injury, anthocyanins have protective effects.These results indicated that the anthocyanins had neuroprective effect on both animal model and cell model of cerebral ischemia reperfusion injury. The mechanism of action was that anthocyanins can minimize the cerebral ischemia reperfusion injury to nerve cells through antioxidation, scaveng free radical and anti-inflammatory.