Neuroprotection effects of Cudraisoflavones and extracts from the fruit of Maclura tricuspidata against in vitro and in vivo brain ischemic injury models via induction of microRNAs targeting Nox4 mRNA.

Abstract

A brain ischemia is a type of stroke that occurs when insufficient blood flow to the brain. This leads to reperfusion injury as well as. Reperfusion injury is when there blood supply returns to the brain circulation results in inflammation and oxidation damage on brain cell. Many drugs are based on improvements in existing therapies or on an understanding of the molecular mechanisms involved in oxidative stress. Cerebral ischemia is the third leading cause of death in industrial countries. Therefore, it is important to develop new compounds that are effective for the treatment of cerebral ischemia. This study evaluated the neuroprotective effects of Maclura tricuspidata fruits on the two experimental models of cerebral ischemic damage in in vitro model oxygen-glucose deprivation/reoxygenation (OGD/R) and in vivo model middle cerebral artery occlusion/reperfusion (MCAO/R) of cerebral ischemia. Also, the isolated compounds from M.tricuspidata friuits were investigated the protective effects in in vitro model of cerebral ischemia. 50% EtOH extract of M. tricuspidata fruits (FME50) inhibited OGD/R-induced neuronal cell death, ROS generation, and NADPH oxidase 4 (Nox4) expression via induction of Nox4-targeting miRNA-25, miRNA-92a, and miRNA-146a in SH-SY5Y cells. Also, FME50 suppressed OGD/R-induced activation of apoptosis signal-regulating kinase 1 (ASK1)- c-Jun N-terminal kinases1 (JNK1) / p38 mitogen-activated protein kinases (MAPK) signal cascade. Among nine isolates from FME50, cudraisoflavone I (CFI) and cudraisoflavone H (CFH) attenuated OGD/R-induced cell death, ROS generation, and Nox4 expression by regulating miRNA-25, miRNA-92a, and miRNA-146a expression. Furthermore, CFI and CFH inhibited MAPK signal cascade. Furthermore, FME50 significantly reduced the MCAO/R–induced brain infarct, Nox4 expression via induction of Nox4-targeting three miRNAs. Additionally, FME50 suppressed MCAO/R-induced MAPK signal pathway. Taken together, these findings suggest that the neuroprotective effect of FME50 and two isolated compound CFI and CFH on neurotoxicity is in part due to the inhibition of NOX activity and ROS generation. These results demonstrate that FME50, CFI, and CFH exert neuroprotective effects via Nox4 inhibition by the induction of Nox4-targeting miRNAs and inhibition of MAPK signal cascade, suggesting that they might be possible candidates for the treatment of cerebral ischemia.