Superoxide Dismutase response: physiological plasticity in tobacco users.

Background: Free radicals (FRs) are active chemical substances having unpaired electron(s) which participate in the causation of precancerous lesions or cancer in tobacco habituates. Alterations in the antioxidant levels are reflected throughout the antioxidant enzyme activities in blood, wherein erythrocytes are considered highly sensitive to those enzymes. Our study was therefore aimed to assess the effects of tobacco consumption on erythrocyte antioxidant enzyme- Superoxide dismutase (E-SOD) and evaluate its defensive action.

Methods: E-SOD was estimated in 32 participants categorized in 2 groups (tobacco users and controls). 3 mL venous blood was withdrawn and antioxidant levels were assessed using RANSOD kit (Randox, Catalogue No.-125) as per the manufacturer's instructions. The E-SOD activity was then determined using spectrophotometry and the data was statistically evaluated.

Results: The Two-tailed Paired t-test was applied in smokers-SOD intergroup (mean=-124.45, P<0.0001) and chewers-SOD intergroup (mean=-66.70, P=0.1017). The mean SOD values (139.72±36.94) in cases were found to be significantly lower as compared to controls (212.75±37.04). The lowest SOD level was seen with chewers compared to other groups.

Conclusions: E-SOD was found to be lowest among tobacco chewers probably due to the fact of excessive enzyme activity against prolonged release of carcinogens. The variability in the enzyme activity envisaged its potential as a biomarker in establishing the oral potentially malignant disorders (OPMDs) much before the lesions arises or detect the progression of existing lesion to malignancy.