Baicalin attenuates oxygen-glucose deprivation-induced injury by inhibiting oxidative stress-mediated 5-lipoxygenase activation in PC12 cells

Aim: To determine whether the flavonoid baicalin attenuates oxygen-glucose deprivation (OGD)-induced injury by inhibiting oxidative stress-mediated 5-lipoxygenase (5-LOX) activation in PC12 cells. Methods: The effects of baicalin and the 5-LOX inhibitor zileuton on the changes induced by OGD/recovery or H 2 O 2 (an exogenous reactive oxygen species [ROS]) in green fluorescent protein-5-LOX-transfected PC12 cells were compared. Results: Both baicalin and zileuton attenuated OGD/recovery- and H 2 O 2 -induced injury and inhibited OGD/recovery-induced production of 5-LOX metabolites (cysteinyl leukotrienes) in a concentration-dependent manner. However, baicalin did not reduce baseline cysteinyl leukotriene levels. Baicalin also reduced OGD/recovery-induced ROS production and inhibited 5-LOX translocation to the nuclear envelope and p38 phosphorylation induced by OGD/recovery and H 2 O 2 . In contrast, zileuton did not show these effects. Conclusion: Baicalin can inhibit 5-LOX activation after ischemic injury, which may partly result from inhibition of the ROS/p38 mitogen-activated protein kinase pathway.