Ginsenoside Rg1 protects primary cultured rat hippocampal neurons from cell apoptosis induced by ββ-amyloid protein

Objectives: Estrogen is known to prominently benefit neuronal syndromes and neurodegenerative diseases. Ginsenoside Rg1, an active ingredient found in a Chinese plant, ginseng root, was previously demonstrated to exert estrogen-like activity. This study was performed to assess the neuroprotective effect of ginsenoside Rg1 against apoptosis induced by beta-amyloid protein 25-35 (A beta(25-35)) in primary cultured rat hippocampal neuronal cells as well as in the underlying mechanisms. Methods: We first measured cell viability and lactate dehydrogenase (LDH) release from primary cultured rat hippocampal neurons. After that, the inhibition effects of ginsenoside Rg1 on neuronal cell apoptosis were evaluated with flow cytometric analysis. Furthermore, western blot analysis was used for detecting the expression of apoptosis-related proteins Bcl-2, Bax, and active caspase 3. Results: The results show that ginsenoside Rg1 could increase neuronal viability and reduce LDH release; rescue cell apoptosis induced by A beta beta(25--35); decrease the expression of caspase 3, increase the ratio of Bcl-2/Bax at the protein levels compared with the cells only treated with A beta beta(25--35). Conclusions: Taken together, our results indicate that the apoptosis induced by A beta beta(25--35) could be reversed by ginsenoside Rg1. Furthermore, this neuroprotective effect is probably mediated by up-regulating the ratio of Bcl-2/Bax that activates caspase 3.