Ginsenoside Rg1 attenuates β-amyloid-induced apoptosis in mutant PS1 M146L cells

Ginsenoside Rg1 (Rg1) is a pharmaceutically active component of ginseng, and is neuroprotective as reported. This experiment investigated whether Rg1 is effective on injury or apoptosis of Chinese hamster ovary (CHO) cells as induced by Aβ25–35, or by excessive Aβ1–42 and the mechanism involved. We used different Rg1 doses to pretreat CHO cells stably expressing APP751 and either wild-type PS1 (WT) or mutant PS1 (M146L) for 24 h. Cell viability and apoptosis were examined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay, terminal deoxynucleotidyl-transferase-mediated dUTP transferase nick-end labeling (TUNEL), and fluorescent annexin V/propidium iodide (Annexin V-FITC/PI) staining. The expression of Aβ1–42 and caspase-3 was investigated with immunofluorescent staining. Our results reveal that pretreatment with 25 μM Rg1 can improve viability in cells injured by Aβ25–35, inhibit the intracellular Aβ1–42-induced apoptosis in mutant PS1 M146L cells, and reduce the levels of Aβ1–42 and active caspase-3. This study demonstrated that Rg1 can reduce the production of Aβ1–42 and the activation of caspase-3, as a result, to attenuate the cell apoptosis.