The Effects of Cigarette Smoke Inhalation on Antioxidant Vitamins (A, E, C) and Thyroid Hormone Profile in Wistar Rats

Abstract

Introduction: Tobacco smoke inhalation is among the major causes of diseases including cancer and immune-mediated inflammatory diseases as increasing exposure to cigarette smoke pose a public health burden. A growing body of evidence supports a key role for smoking-induced reactive oxygen and nitrogen species that can damage cellular and sub-cellular targets such as lipids, proteins and nucleic acids. This study was carried out to determine the effects of cigarette smoke inhalation on antioxidants vitamins (A, E, C) and thyroid hormone profile in Wistar rats. Aim: This study aimed to determine the effects of cigarette smoke inhalation on antioxidants vitamins (A, E, C) and thyroid hormone profile in Wistar rats. Methodology: Benson and Hedges cigarette (1.0 mg nicotine/stick) was purchased and used in exposing the animals to cigarette smoke at 0, ¼, ½, and 1 stick respectively in acryl plastic cage with inner chamber. A total of 36 adult male wistar rats were used for the study. After 2 weeks of acclimatization, the animals were randomly divided into four groups of nine animals each; group 1 (normal control); groups 2 (exposed to cigarette smoke at concentration of 0.25 mg); group 3 (exposed to cigarette smoke at concentration of 0.5 mg); group 4 (exposed to cigarette smoke at concentration of 1.0 mg) twice daily for one month. After one month of exposure the animals were anaesthetized, blood samples were collected for biochemical study. Results:  Results were analyzed using SPSS and values were significant at p < 0.05. This study showed that, exposure to cigarette smoke at varying concentration significantly (p < 0.05) decreased both the vitamin levels and thyroid hormone concentration in a dose-dependent manner compared to control group rats. Conclusion: The effects of cigarette smoke inhalation on antioxidants vitamins (A, E, C) and thyroid hormone profile in wistar rats showed inhibitory potentials via decreased in vitamins and thyroid stimulating hormone (TSH) levels in a dose-dependent manner. This induces low levels of thyroid peroxidase which stimulate the synthesis of T3 and T4 is being inhibited by thiocyanide as a result of cigarette smoke inhalation. This study suggests that exposure to cigarette smoke inhalation may be considered to cause serious health problem and so, should be minimized or avoided completely.