Sargahydroquinoic acid (SHQA) suppresses cellular senescence through Akt/mTOR signaling pathway

The effects of sargahydroquinoic acid (SHQA) on cellular senescence and the underlying mechanisms were investigated using human umbilical vascular endothelial cells (HUVECs).

SHQA or DMSO was supplemented into the medium. Low dose of H₂O₂ was used to induce premature senescence. Replicative senescence was achieved by continuously culturing cells until they reached a plateau phase. Senescence biomarkers, including p53, p21, and p16 proteins, and SA-β-Gal activity were measured.

Pretreatment of SHQA significantly suppressed the oxidative stress-induced protein expression of p53, p21, and p16, as well as the activity of SA-β-Gal. Additionally, SHQA also delayed the replicative senescence as indicated by an increased population doubling number, reduced protein expression of p53, p21, and p16, as well as a decreased SA-β-Gal activity. SHQA inhibited the phosphorylation of Akt, mTOR, and downstream targets of mTOR, such as p-S6K, which was elevated by premature senescence and replicative senescence. In the absence of senescence stimuli, SHQA also inhibited the Akt/mTOR signaling pathway and promoted autophagy.

SHQA suppressed senescence induced by oxidative stress and replication through inhibiting the Akt/mTOR pathway. With the potential of acting as an Akt/mTOR inhibitor, SHQA might be useful for developing anti-ageing therapy.