Chemical constituents and antioxidant potential of African Fruits

Free radicals are unstable species that are formed from cellular metabolic processes and a certain concentration of these unstable and reactive species confers acceptable effects on the immune activities in biological systems. These free radicals can become harmful to the cell when their levels exceed that of the cellular antioxidant system, in a process known as oxidative stress. Fruits and vegetables are used for nutritional purposes and as therapeutics to treat several diseases and ailments due to the presence of natural products in these food items. Inadequate dietary manners and lifestyles are linked to oxidative stress and can stimulate a disparity between the antioxidant defense system and the production of reactive radicals in the body. Therefore, there is an increasing interest in the consumption of plants and their parts with high contents of natural antioxidants. People consume fruits due to the presence of reactive radicals scavenging and health-promoting bioactive compounds. They also contain both micro- and macronutrients and fibers, in addition to secondary metabolites which make them unique as a source of antioxidants. Africa is a region with a wide range of different fruits such as African custard-apple (Annona senegalensis Pers), Guava (Psidium guajava L.), Pawpaw (Carica papaya), Prickly Pears (Opuntia spp), Longkong (Lansium domesticum Corr.), Loquat (Eriobotrya japonica), Rambutan fruit (Nephelium lappaceum L.) among others. These fruits serve as a reservoir for natural antioxidants such as phenolics, flavonoids, stilbenoids, tannins, and terpenoids, among others that could play an essential role in treating and managing several oxidative stress-related diseases and the synthesis of plant-based drugs. Fruit-based antioxidants exert their action through suppression and inhibition of free radical generation, prevention of lipid peroxidation, chelating action, and others. Accordingly, this review summarizes the literature that deals with various fruits from Africa as potential sources of natural antioxidants and their role in the management of diseases related to oxidative stress. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.