Phytochemicals and REDOX Modulation: Molecular Mechanisms, Clinical Relevance, and Therapeutic Perspectives

Oxidative stress and redox (REDOX) imbalance play a key role in the development of many chronic and degenerative disorders, including cardiovascular diseases, neurodegenerative conditions, cancer, and age-related illnesses. Beyond causing direct damage to macromolecules, disrupted REDOX signaling affects cellular homeostasis, alters inflammatory responses, and modifies metabolic control, leading to disease onset and progression. Therefore, targeting oxidative pathways offers a promising therapeutic approach for managing chronic diseases. Naturally derived antioxidants, especially phytochemicals such as polyphenols, flavonoids, and carotenoids, have been identified as novel REDOX modulators with diverse biological effects that extend beyond simple free-radical scavenging. This review provides a detailed overview of the molecular mechanisms through which these phytochemicals influence oxidative pathways and exert protective effects on cells. We discuss their relevance in oxidative stress–related diseases, evaluate current clinical evidence regarding their efficacy, and highlight key challenges that limit their clinical application. Special attention is given to the roles of bioavailability, metabolism, and gut microbiota in shaping health outcomes associated with phytochemical consumption. Additionally, we outline emerging strategies to enhance phytochemical efficacy, including synergistic combinations and advanced delivery systems. Overall, this article underscores the potential of phytochemicals as active modulators of REDOX biology, supporting their role in precision nutrition and modern therapeutic approaches.