Neuroprotective Effect of Perilla Extracts on PC12 Cells

Perilla frutescens (L) Britton contains some active principles which had neuroprotective actions.

The present study was aimed to investigate the effect of Perilla extracts on neuroprotection, antioxidation and neurite outgrowth in PC12 cells.

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.

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.

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.