Salivary superoxide dismutase activity in smokeless tobacco consumers and non-consumers: A biochemical study

Tobacco can alter the antioxidative capacity of saliva, and it is the first fluid that is exposed to tobacco. Superoxide dismutase (SOD) is the first line defense antioxidant that plays an important protective role against peroxidation of lipids, converts superoxide radicals into hydrogen peroxide, and decreases the toxic effects of free radicals. The aim of this study was to estimate and compare the levels and activity of SOD in the saliva of smokeless tobacco (SLT) consumers and non-consumers.

Total of 64 individuals were divided into two groups (study and control) with 32 patients each. The patients were divided into two groups-Group I: 32 healthy individuals who do not consume SLT (control group) and Group II: 32 individuals who consume SLT for a period more than 1 year (study group). Saliva samples were collected for analysis from both the groups.

The results of this study showed that antioxidant salivary SOD enzyme activity in tobacco chewers is higher in comparison to non-chewers.

The present study enlightens us to the possible relationship between SOD enzyme levels, oxidative stress, and tobacco habit. In initial or early stages, antioxidant levels increase, thereby showing an evidence of endogenous activity. But as the duration of the habit increases, there is decrease in the body's defense mechanism, and the level of SOD starts to fall resulting in oral lesions. This will help in establishing the reliability of SOD in saliva as a potential biomarker of oxidative stress in tobacco chewers. Further, it may also help in establishing the role of oxidative stress in the pathogenesis of premalignant lesions and oral cancer.