Ginsenoside Rg_1 protects PC12 cells against Aβ-induced injury through promotion of mitophagy by PINK1/parkin activation / 中国中药杂志

Amyloid β-protein(Aβ) deposition in the brain is directly responsible for neuronal mitochondrial damage of Alzheimer's disease(AD) patients. Mitophagy, which removes damaged mitochondria, is a vital mode of neuron protection. Ginsenoside Rg_1(Rg_1), with neuroprotective effect, has displayed promising potential for AD treatment. However, the mechanism underlying the neuroprotective effect of Rg_1 has not been fully elucidated. The present study investigated the effects of ginsenoside Rg_(1 )on the autophagy of PC12 cells injured by Aβ_(25-35) to gain insight into the neuroprotective mechanism of Rg_1. The autophagy inducer rapamycin and the autophagy inhi-bitor chloroquine were used to verify the correlation between the neuroprotective effect of Rg_1 and autophagy. The results showed that Rg_1 enhanced the viability and increased the mitochondrial membrane potential of Aβ-injured PC12 cells, while these changes were blocked by chloroquine. Furthermore, Rg_(1 )treatment increased the LC3Ⅱ/Ⅰ protein ratio, promoted the depletion of p62 protein, up-regulated the protein levels of PINK1 and parkin, and reduced the amount of autophagy adaptor OPTN, which indicated the enhancement of autophagy. After the silencing of PINK1, a key regulatory site of mitophagy, Rg_1 could not increase the expression of PINK1 and parkin or the amount of NDP52, whereas it can still increase the LC3Ⅱ/Ⅰ protein ratio and promote the depletion of OPTN protein which indicated the enhancement of autophagy. Collectively, the results of this study imply that Rg_1 can promote autophagy of PC12 cells injured by Aβ, and may reduce Aβ-induced mitochondrial damage by promoting PINK1-dependent mitophagy, which may be one of the key mechanisms of its neuroprotective effect.

Content Determination of Total Flavones and Polysaccharides in Hedysari Radix in Different Producing Areas in Gansu Province / 中国中医药信息杂志

Objective To establish a method for content determination of total flavones and polysaccharides in Hedysari Radix in different producing areas in Gansu Province.Methods The contents of total flavones and polysaccharides in Hedysari Radix in different producing areas in Gansu Province were determined by ultraviolet spectroscopy with calycosin-7-glucoside and glucose as reference substance, and the wavelength was set at 260 nm and 484 nm.Results The contents were from 2.82 mg/g to 6.79 mg/g for total flavones and from 106.14 mg/g to 746.40 mg/g for total polysaccharides in Hedysari Radix in different producing areas in Gansu Province. The recoveries of total flavones and total polysaccharides were 97.96％ and 102.90％, respectively.Conclusion There was difference in contents of total flavones and polysaccharides of Hedysari Radix in different producing areas in Gansu Province, and the method of using ultraviolet spectroscopy is simple, reproducible, accurate and reliable, which can be preferably used as the method for content determination of total flavones and polysaccharides in Hedysari Radix.