The Effects Of Ginsenoside Rg1 On The Cell Models Induced By H₂O₂ And Aβ_25-35 In Patients With Alzheimer's Disease

Objective It is widely believed that Alzheimer's disease (AD) is one of the nervous retrograde diseases with complex pathologic mechanism. The pathological characteristics are mainly neurofibrillar tangling, occurrence of senile plaques and loss of neutrons. The unusual increase and deposition of amyloid P-peptide in the brain of patients with AD is the major factors leading to irreversible neutral degeneration. Kaixinsan, a traditional Chinese medicine, prepared according to the ancient medical formula, proved to be clinically beneficial in developing people's intelligence. While many reports of the effects of Kaixinsan on Ad are available nowadays, few reports on the effects of some active components of Kaixinsan on AD can be found. H₂O₂ and Aβ_25-35 were used to result in the deaths of SK-N-SH cells, and cell models were prepared by imitating the pathological changes caused by AD, the purpose of which is to investigate the protective effects of ginsenoside Rgl on models of injured nerve cells, to study their molecular mechanism and to provide experimental evidence for the curative effects of this traditional Chinese Medicine in treating nervous regressive diseases. Methods1. Medium of appropriate concentration of ginsenoside Rgl was prepared.2. Models of AD cells were prepared by determining the survival rate of cells with MMT and selecting the optimal conditions to construct models of injured cell (20μM of Aβ_25-35 used for 24 hours, and 100μmol/L of H₂O₂ used for 12 hours). 3. Vitality of cells were determined through MTT colorimetric method, death rate of cells were calculated with the help of flow cytometer, Fragments of dead cells were observe through DNA ladder, the contents of cell culture fluid and MDA and the activity of SOD were detected through chemical colorimetric method, the expressions of amyloid precursor protein (APP) genes and neutral endopeptase genes, as well as the level of expressions of cell bcl-2,and bax, were determined through RT-PCR, and the expressions of APP genes and NEP genes were detected through Western Blot method. Results When SK-N-SH cells were induced by 100μmol/L of H₂O₂ for12 hours, the activity of cells decreased (P<0.01), the death rate of cells was 16.3%, DNA broke into fragments, the content of MDA in culture fluid and cells increased, the activity of Sod declined and the expressions of bax rose conspicuously. When SK-N-SH cells were induce by 20μmol/L of Aβ_25-35 for 24 hours, the activity of cells declined(P<0.01), the death rate of cells was 33.9%, DNA broke into fragments, the content of MDA in culture fluid and cells rose and the activity of SOD decrease. Ginsenoside Rgl could be used to increase the survival rate of cells, decrease the injury of cell and the content of MDA in culture fluid and cells and improve the activity of SOD(p<0.01). The RT-PCR examination results revealed that ginsenoside Rgl could reduce the content of genetic expressions of bax and APP genes and increase the expressions of NEP genes. Western Blot examination results showed that ginsenoside Rgl could reduce the expressions of APP genes and increase the expressions of NEP genes. Conclusion Models of pathologically injured cells in patients with AD can be got by using a certain dosage of H₂O₂ and Aβ_25-35 . Ginsenoside Rgl can be used to fight against cytotoxicity caused by H₂O₂ and Aβ_25-35. The pathological mechanism of which may be related to the fact that ginsenoside Rgl can improve the antioxidation of SK-N-SH cells, decrease the expressions of APP genes and increase the expressions of NEP genes, and therefore, can inhibit apoptosis.