Rooibos (Aspalathus linearis) and its Major Flavonoids — Potential Against Oxidative Stress-Induced Conditions

Abstract

Reactive species are products of normal cellular metabolism and may be deleterious or beneficial. At low/moderate concentrations, reactive species are involved in physiological roles including cell signalling, defense against infectious agents and mitogenic responses. However, unbalanced defense mechanism of antioxidants, overproduction of reactive species or incorporation of free radicals into the living system from the environment may result in oxidative stress, a deleterious process that can lead to damage of important cell structures, including lipids and membranes, proteins and nucleic acids. The role of oxidative stress as a contributing factor in the pathophysiology of various diseases is increasingly being recognized, and augmenting the oxidative defense capacity of the cell through the intake of antioxidants as a way of preventing free radical-mediated cellular injuries is becoming a popular strategy. Much attention is being focused on the health beneficial role of phenolic phytochemicals derived from plants. They are considered to play an important role as physiologically functional foods and for the prevention of clinical conditions related to oxidative stress, even though their modes of action may still not be fully understood. Rooibos ɭAspalathus linearisɮ is a popular South African tisane enjoyed for its taste and aroma. Rooibos has been made in the Cederberg mountain region of South Africa for generations and has been used medicinally for alleviation of allergies, asthma, infantile colic and skin problems. The potential antioxidative, immune-modulating, chemopreventive and chemotherapeutic actions of rooibos have been reported in several studies. This review provides a comprehensive data on the current knowledge of the biological and chemotherapeutic activity of rooibos and its major flavonoids. Most recent in vitro and in vivo ɭanimal and humanɮ studies were conducted with special attention paid to clinical conditions in which oxidative stress has been implicated. The conclusion described directions for future rooibos research to establish its activity and utility as a human chemopreventive and therapeutic agent.Keywords: Antioxidant, Chemoprevention, Oxidative stress, reactive oxygen species, Rooibos © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. . IntroductionOxidative stress results when there is a disturbance in normal cellular and molecular function as a result of an imbalance between the production of various oxidizing chemical species ɭpro-oxidantsɮ and natural antioxidant ability of cells in favour of the former. Pro-oxidants are made up primarily of free radicals, which are chemical species ɭmolecule, ion or atomɮ that contains an unpaired or an odd electron in their outer orbit. As a result of the presence of unpaired electrons, free...

Fumonisin B1‐induced mitochondrial toxicity and hepatoprotective potential of rooibos: An update

“…Their study revealed that involvement of antioxidant properties of the different teas modulates the oxidative stress during FB1‐induced cancer promotion by selectively affecting the antioxidant capacity, antioxidant enzymes and the level of lipid peroxidation presumably due to differences in their polyphenolic constituents, with rooibos extracts showing strong antioxidant effects (Marnewick et al, 2009). When compared with the Camellia sinensis teas (black and green teas) rooibos has a very low tannin content and contains no caffeine, rendering it a healthy alternative bearing in mind its bioactivities shown to date (Ajuwon, Marnewick, & Davids, 2015; Bramati et al, 2002; Stander, Joubert, & De Beer, 2019) When considering the above mentioned we suggest the potential use of rooibos, which possesses a unique composition of and novel phytochemicals known to encompass distinct and varied bioactive properties (Ajuwon et al, 2015; Bramati et al, 2002), which in combination may alleviate cell stress and toxicity after exposure to FB 1 .…”

Protective action of glutamine in rats with severe acute liver failure

“…Because of their unique chemical characteristics, ROS and RNS can trigger lipid peroxidation and cause DNA strand breaks and protein oxidation, resulting in cellular injury. Oxidative and nitrosative stress represents an imbalance in the production and elimination of these reactive species and a decrease in the production of antioxidants[5,11,12].…”

“…The antioxidant defense system is essential for cell protection. Antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as non-enzymatic electron receptors such as glutathione (GSH), are affected by oxidative stress conditions[12,13]. The nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of redox balance.…”

The Potential of South African Herbal Tisanes, Rooibos and Honeybush in the Management of Type 2 Diabetes Mellitus

“…Experimental and clinical evidence has shown that oxidative stress, endothelial dysfunction and chronic inflammation are interrelated in the pathophysiology of T2DM. Overproduction of free radicals has been suggested to be involved in the onset of T2DM and diabetic complications with oxidative stress proposed as a pathogenic mechanism linking insulin resistance with β-cells and endothelial dysfunction, impaired glucose tolerance and overt diabetes [5]. Hyperglycemia is reported to lead to overproduction of reactive oxygen species (ROS) which may result in β-cells dysfunction due to decrease in β-cells mass attributed to oxidative stress-induced apoptosis [6].…”