Material basis, effect, and mechanism of ethanol extract of Pinellia ternata tubers on oxidative stress-induced cell senescence.

ABSTRACT

BACKGROUND: The tuber of Pinellia ternata has been used for a thousand years in China. P. ternata possessed the activities of anti-emetic, sedative-hypnotic, anti-cancer, anti-asthmatic, anti-tussive, and anti-inflammatory. It is the representative of expectorant medicines in Traditional Chinese Medicine (TCM). Phlegm is the pathological product and a new pathogenic factor of the metabolite, which is analogous to the damage of oxidative stress. PURPOSE: The objectives of the study were to investigate the protective activity and mechanism of ethanol extract of P. ternata tubers (PTE) and its main constituents on oxidative stress-induced cell senescence. METHODS: H2O2 and AAPH were used to establish cellular senescence models. The anti-aging effects of PTE and its components were evaluated by SA-ß-gal staining, flow cytometry, scanning electron microscope (SEM), and multiple microplate reader, the molecular mechanisms of them were investigated by qRT-PCR and Western Blot. RESULTS: We found PTE exhibited the apparent effect on cell senescence, evidenced by inhibiting senescence ß-Galactosidase (SA-ß-gal) expression, lipofuscin accumulation, cell cycle arrest at the G2/M phase, oxidative damage and apoptosis, and increasing telomerase activity. Their mechanisms were related to increase expressions of SIRT1, forkhead box 3a (Foxo3a), Bcl-2, active regulator of SIRT1, RPS19BP1 (AROS), and Hu antigen R (HuR), but decrease Bax, p53 and deleted in breast cancer 1 (DBC1) levels. Furthermore, adenosine, and succinic acid, as the critical substances in PTE, could also inhibit SA-ß-gal expression and cell cycle arrest, down-regulate the expression of Bax, and up-regulate Bcl-2, SirT1, and Foxo3a. CONCLUSIONS: We have demonstrated that PTE slows down oxidative stress-induced cell senescence, and adenosine and succinic acid are the key active components.