Magnolol protects PC12 cells from hydrogen peroxide or 6-hydroxydopamine induced cytotoxicity.
J Toxicol Sci. 2019 ;44(11):753-758. PMID: 31708532
Magnoliae Cortex contains a range of bioactive components including terpenes (e.g.α-, β- and γ-eudesmol), phenylpropanoids (e.g. honokiol and magnolol) and alkaloids (e.g. magnocurarine). We recently reported that pretreatment of PC12 cells with Magnoliae Cortex extract significantly suppresses cytotoxicity induced by HOor 6-hydroxydopamine (6-OHDA) through the induction of drug-metabolizing and antioxidant enzymes. In this study, we investigated whether honokiol and magnolol, which are known to be active components of Magnoliae Cortex, induce drug-metabolizing enzymes and antioxidant enzymes in PC12 cells. We also examined the cytoprotective effect of honokiol and magnolol against HOor 6-OHDA induced cell death in PC12 cells. Our results revealed that honokiol and magnolol induced both NAD(P)H:quinone oxidoreductase 1 (NQO1) and catalase enzyme activities in a concentration-dependent manner. Pretreatment of PC12 cells with magnolol suppressed toxicity induced by HOor 6-OHDA. However, pretreatment of PC12 cells with honokiol showed only a suppressive effect on toxicity induced by HO. Our results suggest that the cytoprotective effect of Magnoliae Cortex extract on PC12 cells is mainly attributable to magnolol and only partially to honokiol.