The Multidirectional Biological Activity of Resveratrol: Molecular Mechanisms, Systemic Effects and Therapeutic Potential—A Review

<b>Background/Objectives:</b> Resveratrol is a multi-target polyphenolic stilbene widely studied for its antioxidant, anti-inflammatory, cardioprotective, hepatoprotective, neuroprotective, immunomodulatory and anticancer properties. This review summarizes current evidence on its molecular mechanisms, therapeutic potential, metabolic interactions and biological implications, with particular emphasis on bioavailability, signaling pathways and organ-specific actions. <b>Methods:</b> A comprehensive literature review was conducted focusing on recent in vitro, in vivo and clinical studies evaluating resveratrol's biochemical activity, molecular targets and physiological effects. Special attention was given to oxidative stress regulation, inflammatory signaling, mitochondrial function, metabolic pathways, gut microbiota interactions, and its influence on chronic diseases. <b>Results:</b> Resveratrol modulates several key signaling pathways including NF-κB, SIRT1, AMPK, MAPK, Nrf2 and PI3K/AKT/mTOR. It reduces oxidative stress, inhibits inflammatory cytokines, regulates apoptosis, improves mitochondrial performance, and activates endogenous antioxidant systems. The compound demonstrates protective effects in cardiovascular diseases, hepatic steatosis, neurodegenerative disorders, metabolic dysfunction, and various cancers through anti-inflammatory, anti-proliferative and anti-fibrotic mechanisms. Additionally, resveratrol beneficially alters gut microbiota composition and microbial metabolites, contributing to improved metabolic homeostasis. Despite high intestinal absorption, systemic bioavailability remains low; however, novel nanoformulations significantly enhance its stability and plasma concentrations. <b>Conclusions:</b> Resveratrol exhibits broad therapeutic potential driven by its capacity to regulate oxidative, inflammatory, metabolic and apoptotic pathways at multiple levels. Its pleiotropic activity makes it a promising candidate for prevention and complementary treatment of chronic diseases. Advances in delivery systems and microbiota-derived metabolites may further enhance its clinical applicability.