Abstract: The aim of this study was to investigate the effects of the aqueous extracts of Ganoderma leucocontextum on differentiation of rat pheochromocytoma(PC-12)cells.Cytotoxic effects of G.leucocontextum aqueous extracts towards PC12 cells were determined by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.The potentiation of neuritogenic activity was assessed by neurite outgrowth stimulation assay and alteration of neuronal morphology was visualized by immunofluorescence staining of the neurofilament.Involvement of cellular signaling pathways,the Trk protooncogene family member,TrkA,mitogen-activated protein kinase kinase/extracellular signal-regulated kinase(MEK/ERK1/2)and phosphoinositide-3-kinase/protein kinase B(PI3K/Akt)in mushrooms-stimulated neuritogenesis were examined by using specific pharmacological inhibitors.The aqueous extracts of G.leucocontextum caused a marked stimulation of neuritogenesis with no detectable cytotoxic effects towards PC-12 cells.The activation of TrkA,MEK/ERK1/2 and PI3K/Akt signaling pathways were necessary for the NGF and aqueous extracts to promote neuritogenesis. G.leucocontextum aqueous extracts may contain NGF-like bioactive compound(s)and had potential neuritogenic effects in preventing and treating neurological disorders.

Key words: Ganoderma leucocontextum, PC-12 cell, neuritogenic activity