Investigation of the Role of Culinary and Medicinal Mushrooms in Neurodevelopment by Using Differentiating Neuroblastoma-2a Cells

摘要

Neurite outgrowth is an essential part for establishment of synaptic connections during early development.Accumulated evidences suggested that culinary-medicinal mushrooms play a pivotal role in the prevention of many age-associated neurological dysfunctions.We had shown that Hericium erinaceus (Bull.:Fr) Pers.(lion's mane mushroom,Yamabushitake) grown in tropical areas,Lignosus rhinocerotis (Cooke) Ryvarden (tiger's milk mushroom),and Pleurotus giganteus (Berk.) Karunarathna & K.D.Hyde (cow's stomach mushroom) exhibited stimulatory activity of neurite outgrowth using NG 108-15 and PC 12 cell lines.This observation raised a question with respect to the neurodevelopmental effects,if any,of culinary-medicinal mushrooms.Thus,we aimed to screen and evaluate neurite outgrowth stimulatory effects of selected culinary-medicinal mushrooms using neuroblastoma-2a (N2a) cells (ATCC CCL-131).In vitro embryotoxicity or neurotoxicity was investigated using mouse embryonic fibroblast (BALB/3T3) and N2a cellsrespectively.The five mushrooms used in the studied were Ganoderma lucidum (M.A.Curtis:Fr.) P.Karst (Ling Zhi),L.rhinocerotis,P.giganteus,Grifola frondosa (Dicks.Fr.) S.F.Gray (Maitake) and Cordyceps rnilitaris (L.:Fr.) Link (Dong Cong Xia Cao).Neurite length was measured using Image-Pro Insight processor system.After 24h of N2a and BALB/3T3 cells wasexposured to mushroom extracts,no toxic effect was observed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay.The positive control,nerve growth factor (NGF) induced 26.4 ± 3.6％ in neurite-bearing cells.Aqueous extracts of G.lucidum,L.rhinocerus,P.giganteus and G.frondosa as well as ethanol extract of C militaris significantly (p＜ 0.05) promoted the neurite outgrowth in N2a cells.The average neurite length of NGF-stimulated cells was 78.58 ± 18.6 tm,which was approximately 4× longer than the cell body.Cells treated with G.lucidum were found to develop the longest neurite length,followed by P.giganteus.As a conclusion,our results showed that the mushrooms had the potential in promoting neurite outgrowth during neurodevelopment.The synergism of the various active entities in these mushroom extracts may be responsible for the activity.The signalling pathways involved is yet to be elucidated,but based on our previous results,phosphorylation and activation of the ERK and Akt may be involved.