Plant-sourced Antioxidants in Human Health: A State-of-Art Review

Abstract: Nowadays, free radical chemistry is a field that has gained the wider attention of researchers. Our body generates free radicals’ reactive nitrogen and oxygen species through subjection to several pathological states, endogenous systems, and physicochemical conditions. For the physiological state to occur, it is compulsory to propel a balance between antioxidants and free radicals. Oxidative stress will set in when free radicals can no longer be regulated in the body system. Moreover, free radicals negatively affect DNA, protein, and lipids and cause many diseases in the human body. Thus, natural-sourced antioxidants can be used to manage this oxidative stress. Currently, it has been revealed that some synthetic antioxidants, including butylated hydroxyanisole and butylated hydroxytoluene, are hazardous to human health. Therefore, many efforts have been made in search of natural, non-toxic, and effective compounds that possess anti- oxidative properties. Hence, this review comprehensively presents the roles of plant-based antioxidants in resolving the challenging issues associated with free radical diseases in human beings. It further reviews the characteristics and occurrences of free radicals in the human body, the formation and mechanism of free radicals, some of the physiological impacts of free radicals on human health, sources of free radicals, and plant-sourced antioxidants as a frontier in managing free radicals.