Konzo is a toxico-nutritional neurological disease associated with oxidative damage induced by cyanide poisoning through the ingestion of poorly processed bitter cassava. Dietary uses and patterns, determined using food frequency questionnaires, structured interviews and direct observation in consenting households to Kahemba, the rural area most affected by konzo in the world, showed that the diet of affected population is not varied and largely dependent on cassava (Manihot esculenta Crantz) products. Commonly consumed foodstuffs include herbal teas, mushrooms, spices, vegetables and yams. Phytochemical composition of extracts revealed that they contained flavonoids and phenolic acids as major compounds. All extracts of investigated traditional foods at the concentration range of 0.25–20 μg/mL, displayed high radical scavenging and cellular antioxidant activities using lucigenin on equine neutrophils, related to their phenolic content. The leaves of Manihot esculenta and Manihot glaziovii exhibited the highest antioxidant activity among vegetables. Lippia multiflora is the most active of the herbal teas, Auricularia delicata of mushrooms, Dioscorea alata of yams and Ocimum basilicum of spices. Traditional foods showed more efficient effects on extracellular ROS production and MPO activity. Traditional foods have interesting antioxidant, anti-inflammatory properties and could putatively be used as functional foods or nutraceuticals in the prevention of oxidative damage associated with konzo.
Part of the book: Antioxidants in Foods and Its Applications
Glutathione peroxidase (GPx) is a selenoprotein with biological properties that allow the detoxification of endogenous or exogenous reactive oxygen species as well as the elimination of xenobiotic compounds in the cells. Due to its isoform activities and pathophysiological functions, GPx holds the status of a redox system (GSH/GSSG) in the glutathione (GSH) system to prevent oxidative damage of cellular constituents. As such, the GPx is the first line of defense against free radicals. Its deficiency causes oxidative stress that not only promotes the oxidation of proteins and deoxyribonucleic acid (DNA) but also leads to insulin resistance, dyslipidemia, inflammation, and metabolic alterations, which expose to high risk for cardiometabolic disorders due to cardiovascular and degenerative diseases especially when associated with aging. This work presents a review of different studies done on the localization of GPx in subcellular organelles, activity changes during cellular aging, their effects on cardiometabolic risks, and associated diseases.
Part of the book: Glutathione System and Oxidative Stress in Health and Disease
Oxidative stress, characterized by excessive production of reactive species, is involved in several chronic diseases such as cardiovascular, chronic obstructive pulmonary, sickle cell, chronic kidney, neurodegenerative, and cancer. The negative impact of ROS and RNS, produced by endogenous and exogenous processes, is neutralized by antioxidant defenses. Given the importance of oxidative stress to human health, the use of antioxidants as therapy directs medical research toward the specificity of antioxidants causing each disease. Fruits and vegetables contain antioxidants, such as nutraceuticals, pharmaceuticals, and phytoceuticals, the consumption of which reduces the risk of developing chronic diseases. Flora of African countries is endowed with plant species that would make a putative source for new antioxidants. This article reports antioxidant activities of traditional foods from Democratic Republic of the Congo. Further studies are needed to ensure mechanisms of their functionality in the human body.
Part of the book: Recent Developments in Antioxidants from Natural Sources