%0 Journal Article
%T Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates
%A Namratha Pai Kotebagilu
%A Vanitha Reddy Palvai
%A Asna Urooj
%J International Journal of Medicinal Chemistry
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/861084
%X Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates¡ªRBC and microsomes. The antioxidative ability of three solvent extracts, methanol (100% and 80%) and aqueous leaf extracts, was studied at different concentrations by thiobarbituric acid reactive substances method using Fenton¡¯s reagent to induce oxidation in the substrates. The polyphenol and flavonoid content were analyzed to relate with the observed antioxidant effect of the extracts. The phytochemical screening indicated the presence of flavonoids, polyphenols, tannins, and ¦Â-carotene in the samples. In microsomes, 80% methanol extract of Canthium and Costus and, in RBC, 80% methanol extract of Costus showed highest inhibition of oxidation and correlated well with the polyphenol and flavonoid content. From the results it can be concluded that antioxidants from medicinal plants are capable of inhibiting oxidation in biological systems, suggesting scope for their use as nutraceuticals. 1. Introduction It is well known that oxidant by-products of normal metabolism such as free radicals and reactive oxygen species (ROS) in excess can cause extensive damage to DNA, proteins, and lipids [1]. Under stress, the body produces more ROS, such as superoxide anion and hydroxyl radical, which are highly reactive and potentially damaging transient chemical species. These are continuously produced in the human body, as they are essential for energy supply, detoxification, chemical signaling, and immune function. Overproduction of free radicals and ROS induced by exposure to external oxidant substances or a failure in the defense mechanisms causes oxidative stress in turn leading to various degenerative diseases of aging such as cancer, cardiovascular disease, cataracts, immune system decline, and brain dysfunction [2, 3]. Antioxidants reduce the oxidative stress in cells and are therefore useful in the treatment of many human diseases. There are various endogenous and exogenous sources of antioxidants. The endogenous sources include antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and low-molecular weight antioxidants and exogenous sources such as food sources and medicinal
%U http://www.hindawi.com/journals/ijmc/2014/861084/