Asarone from Acori Tatarinowii Rhizome prevents oxidative stress-induced cell injury in cultured astrocytes: A signaling triggered by Akt activation

Acori Tatarinowii Rhizome (ATR; the dried rhizome of Acori tatarinowii Schott) is a well-known herb being used for mental disorder in China and Asia. Volatile oil is considered as the active ingredient of ATR, and asarones account for more than 90% of total volatile oil. Here, the protective effects of ATR oil and asarones, both α-asarone and β-asarone, were probed in cultured rat astrocytes. The cyto-protective effect of ATR oil and asarones against tBHP-induced astrocyte injury was revealed, and additionally ATR oil and asarones reduced the tBHP-induced intracellular reactive oxygen species (ROS) accumulation. In parallel, the activity of anti-oxidant response element (ARE) promoter construct (pARE-Luc), being transfected in cultured astrocytes, was markedly induced by application of ATR oil and asarones. The mRNAs encoding anti-oxidant enzymes, e.g. glutathione S-transferase (GST), glutamate-cysteine ligase modulatory subunit (GCLM), glutamate-cysteine ligase catalytic subunit (GCLC) and NAD(P)H quinone oxidoreductase (NQO1) were induced by ATR oil and asarones in a dose-dependent manner. The ATR oil/asarone-induced gene expression could be mediated by Akt phosphorylation; because the applied LY294002, a phosphoinositide 3-kinase inhibitor, fully abolished the induction. These results demonstrated that α-asarone and β-asarone could account, at least partly, the function of ATR being a Chinese medicinal herb.