Exploring Hippuric Acid's Putative Protective Role in Aging through In Silico and In Vitro Screening.

Hippuric acid (HA) is a diet- and microbiome-derived metabolite consistently associated with healthy aging, yet whether it is a passive biomarker or an active effector remains unresolved. To investigate mechanisms underlying its protective role, in silico screening of large bioactivity data sets was performed and integrated with results from in vitro assays. A multifingerprint similarity approach was employed to identify close HA analogues and their reported targets. HA analogues were identified with reported potencies in the low-micromolar or nanomolar range toward transporters (solute carriers, organic anion transporters, multidrug resistance-associated proteins), epigenetic regulators (histone deacetylases), and enzymes linked to inflammation, proteostasis, or vascular homeostasis (carbonic anhydrases, cyclooxygenase-2, soluble epoxide hydrolase, neprilysin). Additional evidence pointed to proteins involved in detoxification, energy metabolism, and neurodegeneration (kynureninase, microtubule-associated protein tau, 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase), supporting their plausibility as candidate HA targets. By contrast, database screenings for direct antioxidant or anti-inflammatory activity were mostly inconclusive, whereas in vitro assays suggested limited radical-scavenging activity and no modulation of nitric oxide production pathways. Results suggest that HA's protective associations with aging might involve modulation of specific proteins or transporter-mediated mechanisms, rather than acting solely through target-nonspecific pathways. While these findings remain exploratory and require further confirmation, this integrated in silico and in vitro analysis provides an initial, hypothesis-generating strategy to narrow the spectrum of potential molecular interactions, offering candidate targets to guide future functional in silico, in vitro, and in vivo validation experiments.