Antioxidant Phytochemicals in Environmental Toxicology: Protective Roles against Oxidative Stress from Pollutants and Heavy Metals
Henrietta Marcel
Department of Chemistry, University of Benin, Edo State, Nigeria.
Tolulope A. Durodola
Department of Botany, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria.
Daniel A. Idowu
*
Department of Chemistry, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria.
Benjamin M. Larweh
Department of Biological Sciences, Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development, Kumasi, Ghana.
Agumage Idoko
Department of Pharmacognosy, University of Lagos, Akoko, Lagos State, Nigeria.
Holy J. Giwa
Department of Microbiology, University of Abuja, Gwagwalada, FCT, Nigeria.
Omokhudu G. Igiekhumhe
Department of Environmental Science, Oklahoma State University, Oklahoma, USA.
Emmanuel O. Oko
Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Heavy metal and persistent organic pollution remain a significant health challenge in the world because they have the capability of causing oxidative stress and cellular damages. This oxidative stress arises when the formation of the reactive oxygen species surpasses the abilities of biological antioxidant systems causing molecular and physiological malfunction. Antioxidant phytochemicals present in plants have been investigated as potential anti-pollutant agents against toxicity caused by pollutants in recent years. This review has given a detailed account of the mechanisms that these phytochemicals used in mitigating these oxidative stress from environmental toxicants. It covers such key classes of compounds like flavonoids, polyphenols, carotenoids, and phenolic acids and their antioxidant, anti-inflammatory, and metal-chelating activities. The review of experimental, in vivo, and epidemiological research is discussed to demonstrate their functions in restoring redox balance, improving cellular defense mechanisms, and guarding vital organs against the damage by pollutants. Other novel studies about synergistic effects, nano-formulations and interventions with phytochemicals are also noted in the review to enhance bioavailability and therapeutic action. Although these advances have been made, the inconsistency in plant composition, insufficient clinical validation, and metabolic lability are still major issues. Altogether, antioxidant phytochemicals are groups of promising natural intervention in the fight against oxidative stress caused by environmental pollutants, and it is recommended that future studies should focus on the optimization of formulations and how they can be practically applicable to humans.
Keywords: Antioxidant phytochemicals, heavy metals, oxidative stress, redox balance, environmental toxicology, phytochemical defense