Injury Of Ferrous Iron On Astrocytes And Neuroprotection Of Carvacrol In Experimental Intracerebral Hemorrhage

Previous studies have demonstrated that ferrous iron can induce neuroepithelial cell damage through its toxicity. However, it is still unclear that whether ferrous iron can change the aquaporin-4 (AQP4)expression in astrocytes. Also some studies have reported that carvacrol is neuroprotective in central nervous system diseases. However, it remains unclear that whether carvacrol is a potential neuroprotectant in intracerebral hemorrhage. In this study, we investigated the neurotoxicity of ferrous iron on astrocytes and the neuroprotective effect of carvacrol in vitro and in vivo.We assessed the cell viability by Cell Counting Kit 8 after ferrous iron was added into primary cultures of astrocytes. We performed real time RT-PCR and Western Blot to analyze the AQP4 expression of astrocytes. The signaling protein expression of mitogen-activated protein kinases (MAPKs) pathway was also analyzed by Western Blot. After the antioxidants were applied to block the oxidative stress reaction, the AQP4 expression of astrocytes was evaluated. We also assessed the neuroprotective effect of carvarol on ferrous iron-induced astrocyte injury. In vivo, we explored the neuroprotective effect of carvacrol by evaluating neurological function, cerebral edema, blood-brain barrier (BBB) breakdown, and AQP4 expression.Our results showed that ferrous iron induced astrocytes death in a dose-and time-dependent manner. And ferrous iron increased the expression of AQP4, phospho-p38, phospho-ERK and phospho-JNK. The AQP4 expression was inhibited after the antioxidants were applied to block oxidative stress reaction. In vitro, carvacrol could suppress ferrous iron-induced astrocytes death and AQP4 expression increase. In vivo, carvacrol could improve neurological function, reduce cerebral edema and damage of BBB, and decrease the AQP4 expression.Our study suggests that ferrous iron can cause astrocyte injury. The activation of MAPKs pathway activated by ferrous iron-mediated oxidative stress reaction may increase the AQP4 expression. Carvacrol may exert its protective effect on ICH injury by ameliorating AQP4-mediated cerebral edema.