Tehran University Medical Journal

Background: Smoking is a harmful habit and saliva is the first fluid that is exposed to cigarette smoke as a source of oxidant and peroxidant agent. Salivary antioxidant system plays an important role in its anti-cancer potential. Uric acid has a role as antioxidant in the body and could increase plasma antioxidant capacity and has a specific role as inhibitor on radicals and peroxidant agent. Therefore, the aim of this study was to evaluate indicators of oxidative stress or malondialdehyde (MDA) as an important parameter of lipid peroxidation and total antioxidants capacity in smokers and non-smoking persons.

Methods: In this case-control study which was conducted in clinical biochemistry labratory, Mazandaran University of Medical Sciences on Spring 2016. The sample on salivary fluids was collected by spitting method in tubs from 50 smokers (cases group) and nonsmokers (controls group) after all night fasting. As soon as saliva was collected, at the first step total whole salivary fluids were centrifuged and the superior parts were transferred in a tub and stored at -80 ℃ until analyzed. Total antioxidant capacity (TCA) of their saliva was evaluated by Ferric reducing ability of plasma (FRAP) method, lipid peroxidation parameter (MDA) with thiobarbituric acid (TBARS) and uric acid by calorimetry (uricase) methods. The data were analyzed via SPSS software and independent t-test was used to compare the two groups.

Results: Indicators of oxidative stress, in the case group was 1.17±0.29 nmol/ml significantly higher than compared to control group with 0.91±0.16 nmol/ml. TCA in the case group was 220.66±39.68 μmol/l compared to control group 272.26±40.64 μmol/l was significantly lower (P< 0.05).

Conclusion: The result of this study indicates that smoking can reduce total antioxidant capacity and increase lipid peroxidation parameters. In addition, duration of cigarette using has destructive effects on body that it can lead to several diseases. The important thing is to keep trying to quit smoking. For smokers who are willing to quit, it would be recommend that smokers be managed with a combination of behavioral support and pharmacologic therapy.