Original Article EVALUATION OF NON-ENZYMATIC ANTIOXIDANTS IN LUNG CANCER PATIENTS MOHAMMED RAFIQKHAN 1 , SUDHA SELLAPPA 1 * 1* Molecular Diagnosis and Drug Discovery Laboratory, Department of Biotechnology, School of Life Sciences, Karpagam University, Coimbatore, Tamilnadu, India Coimbatore 641021. Email: sudhasellappa@yahoo.co.in Received: 03 Mar 2014 Revised and Accepted: 22 Mar 2014 ABSTRACT Objective: Cancer is one of the leading causes of morbidity and mortality throughout the world and it is the second leading cause of death in most of the developed countries. Smoking is one of the major lifestyle factors influencing the health of human beings. It is known that cigarette smoke and tar phase contain a number of oxidizing compounds, reactive oxygen species and carcinogens, which damage the genome, membranes and macromolecules of cells. The aim of the present investigation was therefore to evaluate the levels of non-enzymatic antioxidants in lung cancer patients and controls. Methods: The non-enzymatic antioxidants included were estimation of reduced glutathione, vitamin C and vitamin E. All the results were expressed as the mean value ±SD and statistical analysis was done by student’s t-test. Results: Assessment of non-enzymatic antioxidants revealed a significant difference (p < 0.05) between lung cancer patients with smoking and controls with smoking habit. The impaired antioxidant system may favour accumulation of free radicals. In the present study, decreased level of non-enzymatic antioxidants was observed. Conclusion: The data indicate that smoking weakens antioxidant defense mechanism, could a major risk factor in carcinogenesis. The results of the present investigation suggest that normalization of the levels of these non-enzymatic antioxidants might be used to reduce lung cancer malignancy. Despite active investigation, knowledge is lacking concerning the local and systemic effects of free radical-generating treatments in lung cancer. Keywords: Lung cancer, Non-enzymatic antioxidants, Reduced glutathione, Vitamin C. INTRODUCTION The lung is the organ with the highest exposure to atmospheric oxygen. Due to its large surface area and rich blood supply, the lung is susceptible to oxidative injury by large numbers of reactive oxygen species (ROS) and nitrogen species, as well as by free radicals. In situ lung injury due to ROS is strongly associated with oxidation of proteins, lipids and DNA. These oxidized biomolecules may also induce a variety of cellular responses with generation of secondary metabolic species [1]. Lung cancer is a leading cause of cancer death internationally, with smoking being the largest single cause. Smoking is responsible for 85–90% of lung cancers, so far <20% of lifetime smokers develop lung cancer, signifying that additional factors, including genetics, may play a role [2]. Tobacco smoking is well established as the major etiological risk factor for lung cancer, contributing to a tenfold increase in risk in long-term smokers compared with non-smokers [3]. Oxidative stress is thus an inevitable consequence of aerobic life. The implication of free radical reactions in the pathogenesis of various diseases is nowadays generally accepted [4]. Human antioxidant defenses have evolved to protect biological systems against reactive oxygen and nitrogen species, and a sophisticated cooperative array of antioxidant defense mechanisms is found in biological systems [5]. To control the influence of ROS, aerobic cells have developed their own antioxidant defense system, which includes both enzymatic and non-enzymatic components [6]. There have been increasing interest in the role of free radicals and antioxidants in cancer during recent years. Damages to DNA, protein, cell membrane and mitochondria are involved in carcinogenesis, although no specific biochemical marker has been identified yet. In addition, information on the biochemical alterations in tissue and blood, particularly of antioxidant status, and its correlation with the clinical staging of the disease, is lacking. The objective of the present study is to investigate potential changes in the non-enzymatic antioxidant status induced by cigarette smoking in lung cancer patients compared to the probability of cancer incidence in healthy subjects. MATERIALS AND METHODS Study Subjects Thirty two male patients who were diagnosed to have lung cancer were studied. Fasting venous blood samples were collected from two groups of males. Each of the main groups included two sub- groups such as smokers and non-smokers. Female patients, patients suffering from moderate or severe hypoxia and patients having chronic systemic disease are excluded in this study. The control group consisted of 17 smokers and 15 non-smokers. The group of cancer patients included 19 smokers and 13 non-smokers. The mean ages of investigated human groups were sufficiently close. The control smokers and non-smokers were of mean age 48 ± 2.8 years; the sub-group of smoking cancer patients was 49 ± 3.2 years and the group of non-smoking patients was 51 ± 2.7 years of age. After obtaining prior consent, venous blood was collected from the subjects under aseptic condition by vein puncture using 5 ml sterile disposable syringe and needle. Plasma was separated by centrifugation at 3000 rpm for 15 minutes. The samples were stored at 4ºC before analysis and all the samples were analyzed on the same day of the collection. The work was carried out in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki. Estimation of Reduced Glutathione (GSH) The GSH content was determined by the method of Ellman (1959) [7]. 1.0 ml of plasma was treated with 0.5 ml of Ellman’s reagent (19.8 mg of 5, 5'-dithiobisnitrobenzoic acid – DTNB in 100 ml of 0.1% sodium nitrate) and 3.0 ml of 0.2M phosphate buffer (pH 8.0). The absorbance was read colorimetrically at 412 nm Estimation of Vitamin C Vitamin C (Ascorbic acid) was determined by the method of Omaye et al (1979) [8]. To 0.5 ml of plasma, 0.5 ml of 2, 4-dinitrophenyl hydrazine (DNPH) reagent and 4% thiourea (in 9N sulphuric acid) was added and incubated for 3 h at room temperature. After International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 6, Issue 5, 2014 Innovare Academic Sciences