Study of Tobacco Habits and Alterations in Enzymatic Antioxidant System in Oral Cancer

Abstract

Aim and Objective: Tobacco is a major etiological factor for oral cancer development, accounting 30–40% of all cancer cases in India. Tobacco consumption generates free radicals and causes oxidative damages. In order to counteract these lethal effects, normal living cells have multiple antioxidant defense systems in a cascade manner. Thus, it seems that studying biological parameters, like antioxidant enzyme system, may be helpful in risk assessment and early diagnosis of oral cancer. Therefore, we analyzed erythrocytic and tissue antioxidant enzyme activities in terms of glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and plasma thiol levels. Materials and Methods: Study included healthy controls with no habit of tobacco (NHT, n = 25), controls with habit of tobacco (WHT, n = 31) and oral cancer patients (n = 52). All the parameters were analyzed with highly sensitive and specific spectrophotometric methods. Results: Erythrocytic SOD and plasma thiol levels were significantly lower (p = 0.03), while GPx and CAT levels were higher (p = 0.017) in WHT as compared to NHT. No significant changes in GST and GR levels were observed between NHT and WHT. GST, GR, SOD and CAT activities were significantly higher (p = 0.05, p < 0.001, p = 0.003 and p < 0.001, respectively) while GPx and thiol levels were lower (p = 0.035 and p < 0.001, respectively) in oral cancer as compared to WHT. Odds ratio for erythrocytic GR, SOD, CAT and plasma thiol showed significantly higher risk of oral cancer development in WHT. Mean levels of SOD and CAT were increased, while GPx and thiol were decreased with the increase in habit duration in oral cancer. GST, GR and SOD activities were significantly higher (p = 0.0001, p = 0.005 and p = 0.005, respectively), while, CAT and thiol levels were lower (p = 0.0001 and p = 0.015, respectively) in malignant tissues as compared to adjacent normal tissues. Conclusion: The data revealed that evaluation of antioxidant enzyme activities and thiol levels in WHT can be helpful to identify individuals at a higher risk of oral cancer development

Oxidative stress in cigarette smoker and smokeless tobacco user among ethnic group north-eastern population of Uttar Pradesh, India

“…7 Tobacco consumption causes oral cancers, 30-40% of cancer cases accounted in India. 8 It is also generates increased oxidative stress and lipid peroxidation (LPO). The gas phase of CS contains free radicals such as superoxide radicals, hydroxyl radicals and hydrogen peroxide (H2O2) turn to causes oxidative stress.…”

“…9,10 Tobacco consumption produces free radicals; it also increased oxidative stress and LPO. 8 Oxidative effects via free radical generation in smokers' cause LPO, oxidation of proteins and damage to tissues mainly that of lung. The antioxidant enzymes superoxide dismutase (SOD) catalyses the dismutation of superoxide anions (O2) to hydrogen peroxide (H2O2), and glutathione peroxidase (GPx), catalase (CAT) catalyzes the degradiation affected by CS resulting in deleterious effects.…”

Analysis of Salivary Antioxidant Levels in Different Clinical Staging and Histological Grading of Oral Squamous Cell Carcinoma: Noninvasive Technique in Dentistry

“…reactive oxygen species cause loss of salivary antioxidant capacity lead development of oral cancer in many tobacco chewers and smokers [4,5]. Antioxidants, on the other hand have a protective role by scavenging the free radicals [6].…”

Role of Measurement of Antioxidant Enzymes in Evaluation of Antioxidant Therapy in Tobacco Abusers with Oral Leukoplakia

“…However, there is scant medical literature on this subject. Although a few earlier studies have demonstrated the status of lipid peroxidation and antioxidant defense mechanism in plasma and erythrocytes of oral cancer [7][8][9][10], there are no reports on lipid peroxidation and antioxidant therapy in patients with leukoplakia in a specific sub-group of tobacco abusers. Against this background, a prospective study with control was carried out in tobacco abusers:…”