Background: This study determines the protein carbonyls which cause cellular damage and glutathione, glutathione peroxidase, glutathione reductase act as antioxidants.
Materials and Methods:This study was carried out in different categories of pulmonary and extra pulmonary tuberculosis cases of newly sputum culture positive diagnosed pulmonary categorie I (n=100), extra pulmonary patients categorie (n=35) before and after the DOTS treatment of 6 months, categorie II (n=100), categorie III (n=100) and in normal control subjects (n=100).
Results:The serum protein carbonyl levels were significantly increased in the pulmonary and extra pulmonary tuberculosis patients. The activities of blood glutathione, glutathione per oxidase, and glutathione reductase were found to be significantly decreased in subjects of all the categories of pulmonary and extra pulmonary tuberculosis. A negative correlation between the carbonyl protein content and glutathione, glutathione peroxidase, and glutathione reductase was seen in pulmonary tuberculosis, p<0.001.
Conclusion:Increased antioxidant defense mechanism due to increase oxidative stress in tuberculosis. The changes were reversed after 6 months of antitubercular treatment in patients with a good recovery, but the increase in the oxidative stress was not completely reversed.
INTRODUCTIONTuberculosis is a chronic granulomatous disease which is caused by Koch's bacilli, which is called Mycobacterium tuberculosis. The lung is the portal entry of Mycobacterium tuberculosis and it provides a congenial environment for this slowly replicating pathogen. The infection is established in the alveolar macrophages of the distal alveoli [1]. Proteins constitute the major 'working force' for all forms of biological work. The Reactive Oxygen and Nitrogen Species (ROS and RNS) are formed in higher fluxes under pathological conditions. They cause cellular damage due to the oxidation of amino acid residues on proteins, forming protein carbonyls [2] (aldehydes, ketones e.g. Lys, Arg, Pro, Thr). Oxidative stress also increases the protein oxidation [3]. The modification of proteins is initiated mainly by reactions with OH; however, the course of the oxidation process is determined by the availability of O 2 and O 2 -or its protonated form (HO 2 ). Collectively, these reactive oxygen species can lead to oxidation of the amino residue side chains, formation of protein-protein cross-linkages and oxidation of the protein backbone, resulting in protein fragmentation, that transition metal ions substitute for OH and O 2 - [4].Glutathione, which is involved in the transport of amino acids, acts as a coenzyme for enzymes and it protects against oxygen radicals and toxic compounds [5]. Se-dependent GSH peroxidase is capable of utilizing hydrogen peroxide (H 2 0 2 ) and a variety of organic hydroperoxides as substrates. The Se-independent activity is attributed to the isoenzymes of the GSH S-transferases, particularly GSH S-transferass B which acts on the organic hydroperoxides but not on hydrogen pero...
