In vitro Neuronal Differentiation and Neurite Outgrowth of Rat Pheochromocytoma Cells Evoked by Pleurotus giganteus (Berk. ) Karunarathna K. D. Hyde

摘要

Drugs dedicated to alleviate neurodegenerative diseases like Parkinson's and Alzheimer's diseases are always associated with debilitating side effects. Medicinal mushrooms which harness neuropharmacological compounds may be a promising avenue for protection against such diseases. Pleurotus giganteus (Berk.) Karunarathna & K. D. Hyde which is formerly known as Panus giganteus (Berk.) Corner, has been consumed by the indigenous people in Peninsular Malaysia for many years. Domestication of this wild mushroom is gaining popularity but to our knowledge, little medicinal properties have been reported for this culinary mushroom. First, cytotoxicity of aqueous and ethanolic extracts from the fruiting bodies of Pleurotus giganteus was assessed by using 3-[4,5dimethythiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Neurite outgrowth stimulation assay using PC 12, a rat pheochromocytoma cell line was carried out with nerve growth factor (NGF) as control. To elucidate signaling mechanisms involved by mushroom extract-induced neurite outgrowth, treatment of specific inhibitor for MEK/ERK and PI3K signalling pathway was carried out. Our results showed that both aqueous and ethanolic extracts induced neurite outgrowth of PC12 cells in a dose-and time-dependant manner with no detectable cytotoxic effect. At day 3, 25 μg/mL of aqueous extract and 15 μg/mL of ethanolic extract showed the highest percentage of neuritebearing cells, i. e. 31. 7% ± 1. 1% and 33.3 ±0.9%, respectively. Inhibition treatment results suggested that MEK/ERK signaling was essential for P. giganteus-induced neurite outgrowth. We concluded that Pleurotus giganteus had a potential in the mitigation of neurodegenerative diseases.