Hydrolyzed chicken meat extract and its bioactive cyclopeptides attenuate cellular senescence in HT-22 neurons via promoting autophagy through the SIRT1/AMPK/mTOR pathway

Cellular senescence is a core hallmark of aging and a major risk factor for most chronic diseases. Natural products targeting senescent cells have garnered increasing attention for anti-senescence potential in aging-related disease intervention. Previous studies revealed that hydrolyzed chicken extract (HCE) exerts neuroprotective effects, but its role in senescent cell clearance and underlying mechanisms remains unclear. Here, we investigated the anti-senescent effects and mechanisms of HCE in D-galactose-induced senescent HT-22 hippocampal neurons, compared with the traditional essence of chicken (EC). HCE significantly enhanced cellular antioxidant capacity, reduced SA-β-gal positivity, restored cell cycle progression, inhibited senescence-associated secretory phenotype (SASP) secretion, and promoted autophagic flux, with a slightly stronger efficacy than EC. We further identified cyclo (Val-Pro), cyclo (His-Pro), and cyclo(Gly-Pro) as bioactive components, with cyclo(His-Pro) showing the strongest potency. Mechanistically, HCE and these cyclopeptides exerted effects via SIRT1/AMPK/mTOR-mediated autophagy, which was fully abolished by SIRT1 knockdown or targeted pathway inhibition.