Protocatechuic Acid Alleviates D-Gal-Induced Renal Senescence and Injury in Mice by Regulating Taurine Metabolism

Protocatechuic acid (PCA), a natural phenolic compound with antioxidant and anti-inflammatory properties, has been proposed as a potential therapeutic agent against aging-related diseases. This study investigated the protective effects of PCA on D-galactose (D-gal)-induced renal aging in mice. PCA administration significantly improved renal function, alleviated oxidative stress and inflammatory responses, and ameliorated histopathological abnormalities. Biochemical analyses revealed reductions in serum AGEs, β-galactosidase, creatinine, and blood urea nitrogen, accompanied by restoration of antioxidant enzyme activities and suppression of proinflammatory cytokines. Transcriptomic and metabolomic profiling further demonstrated that PCA reversed D-gal-induced molecular alterations, with integrated multi-omics analysis identifying taurine and hypotaurine metabolism as the key pathway mediating its renoprotective effects. Western blot validation confirmed that PCA regulates CSAD, an enzyme essential for taurine biosynthesis. Collectively, these findings provide novel mechanistic insights into renal aging and highlight PCA as a promising natural agent for delaying kidney senescence through modulation of taurine metabolism.