Background: Perilla frutescens (L) Britton contains some active principles which had neuroprotective actions.
Objective: The present study was aimed to investigate the effect of Perilla extracts on neuroprotection, antioxidation and neurite outgrowth in PC12 cells.
Material and Method: The neuroprotective effect of freeze-dried ethanolic extract from Perilla leaves and cold-pressed seed oil were tested on PC12 induced with beta-amyloid protein. The inhibition of tau-protein hyperphosphorylation and the antioxidant enzyme activity were analyzed. The neurite outgrowth bearing cells were investigated and MEK-1 protein production was analyzed by enzyme immunometric assay.
Results: In PC12 culture induced toxicity by beta-amyloid protein: (1) the decrease in cell viability was attenuated in cells pretreated with leaf extract 200 mg/ml and oil 50 mg/ml; (2) SOD activity seemed to decrease when pretreated cells with the extracts; (3) tau phosphorylation was decreased by pretreated cells with50 mg/ml of oil. Moreover, given Perilla leaf extract or seed oil to PC12 culture, the amount of neurite outgrowth bearing cells increased harmoniously with MEK-1 protein expression.
Conclusion: Perilla leaf extract and seed oil reversed the effect of beta-amyloid induced toxicity by decreasing oxidative stress and inhibition of tau-protein hyperphosphorylation. The enhancement of neurite outgrowth by Perilla extracts was also revealed.

Keywords: Perilla frutescens, Neuroprotection