P-Coumaric Acid: A Multifunctional Dietary Phenolic Acid: Drug Actions, Physiological Processes, and Therapeutic Effects on Human Health

p-Coumaric acid (p-CA) is a dietary hydroxycinnamic phenolic acid abundant in cereals, fruits, and vegetables, with wide-ranging pharmacological and nutraceutical relevance. This review synthesizes current evidence on the biochemical properties and molecular mechanisms underlying its biological activity, including reactive oxygen species scavenging, modulation of NF-kB, MAPK, and PI3K/Akt signaling, and regulation of apoptosis and glucose metabolism. These actions translate into antioxidant, anti-inflammatory, antidiabetic, anticancer, antimicrobial, cardioprotective, and anti-melanogenic effects demonstrated across cellular and animal models. p-CA also shows favorable absorption kinetics and bioavailability relative to related phenolic acids. Collectively, the evidence positions p-coumaric acid as a promising multifunctional bioactive compound with potential applications in disease prevention, functional foods, and nutraceutical development, warranting further clinical validation.