Regulation of Oxidative Stress by Phytochemicals: Implications for Immunity and Cellular Defense

Mpora Kakwanzi Evelyn

Department of Pharmacognosy Kampala International University Uganda

Email: evelyne.mpora@studwc.kiu.ac.ug

                                                                           ABSTRACT
Oxidative stress, resulting from an imbalance between the production of reactive oxygen and nitrogen species (ROS/RNS) and the capacity of endogenous antioxidant defenses, is a central driver of cellular dysfunction, immune dysregulation, and chronic disease. Phytochemicals, a diverse group of bioactive compounds found in fruits, vegetables, herbs, and spices, have emerged as potent regulators of oxidative stress. These compounds not only directly scavenge reactive species but also modulate key signaling networks involved in antioxidant defense, inflammation, apoptosis, and immune response. Through activation of redox-sensitive transcription factors such as nuclear factor erythroid 2–related factor 2 (Nrf2) and inhibition of pro-oxidant enzymes, phytochemicals enhance cellular antioxidative capacity and support immune cell function. This review synthesizes current knowledge on the molecular mechanisms by which phytochemicals regulate oxidative stress and explores the implications for immune regulation and cellular defense. We highlight evidence linking dietary phytochemicals to improved immune homeostasis and disease resistance, discuss their effects on chronic inflammation and cellular signaling pathways, and examine challenges in clinical translation, including bioavailability and individualized responses. Understanding how phytochemicals modulate oxidative stress and immunity provides valuable insights into their potential as therapeutic agents and nutritional interventions in health maintenance and disease prevention.

Keywords: phytochemicals; oxidative stress; immunity; redox signaling; cellular defense.

CITE AS: Mpora Kakwanzi Evelyn (2026). Regulation of Oxidative Stress by Phytochemicals: Implications for Immunity and Cellular Defense. NEWPORT INTERNATIONAL JOURNAL OF BIOLOGICAL AND APPLIED SCIENCES 7(2):42-47.
https://doi.org/10.59298/NIJBAS/2026/7.2.4247