Anti-aging activities of black highland barley bran, chrysoeriol, and its glucuronide derivative on Caenorhabditis elegans

The anti-aging activities and underlying mechanisms of black highland barley bran extract (BHBBE) and its major phenolic components, chrysoeriol (CHR) and chrysoeriol-7-O-β-D-glucuronide (CHRG), were investigated in Caenorhabditis elegans (C. elegans). The effects of BHBBE, CHR, and CHRG at different concentrations were evaluated on lifespan, reproduction, locomotion, stress resistance (heat and ultraviolet [UV] stress), and antioxidant activities (such as superoxide dismutase and catalase activities as well as reactive oxygen species (ROS) and malondialdehyde levels). Furthermore, the expression of longevity-associated genes was examined. Central gene, daf-16, in the anti-aging process of BHBBE, CHR, and CHRG was verified by comparing ROS levels in wild-type N2 C. elegans with daf-16(mu86) mutant strains. Nuclear translocation as a function of DAF-16 protein was assessed. BHBBE, CHR, and CHRG significantly extended C. elegans’ lifespan, improved locomotion, and enhanced stress resistance, without adversely affecting reproduction. Their anti-aging effects were primarily mediated by DAF-16 nuclear translocation via insulin/insulin-like growth factor 1 signaling (IIS). Furthermore, this IIS signaling pathway was associated with antioxidant capacity and stress resistance. Therefore, BHBB, a by-product of grain processing, provides a sustainable, safe, and efficient strategy for anti-aging applications.