7,8-Dihydroxyflavone Protects PC12 Cells against MPP+-Induced Cytotoxicity by Heme Oxygenase-1

7, 8-dihydroxyflavone (7, 8-DHF), a newly-selective tyrosine kinase receptor B (TrkB) agonist, has been well studied for its neurotrophic functions. Our previous study has shown that 7,8-DHF could exert potent neuroprotective effect against 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in PC12 cells without TrkB receptor expression. Howerer, this phenomenon induced by 1-methyl-4-phenylpyridinium(MPP+) has not been elucidated. This study is designed to investigate whether heme oxygenase-1(HO-1)signaling pathway mediate the protection by 7,8-DHF. The results were as follows: MTT assay showed that treatment with MPP+ significantly suppressed the cell viability. 7,8-DHF pretreatment suppressed MPP+-induced cytotoxicity and providing strong protection in PC12 cells. Incubation of 7,8-DHF with the PC12 cells up to 6 h showed it up-regulated the HO-1 expression. Moreover, the PC12 cells pretreatment with ZnPP were found to partially block the protective effect of 7,8-DHF. The present results provided the evidence that 7,8-DHF could protect the PC12 cells against MPP+-induced cytotoxicity through HO-1 pathway.