Abstract
Nicotine is a potential inducer of oxidative stress, which can damage the numerous tissues and biological molecules. Nicotine is first metabolized in liver, and the lung is the main target organ susceptible to smoking; therefore, the purpose of the current examination was scrutinizing the impacts of nicotine on these organs using the histological method, and studying the ameliorative (additive or synergistic) effects of quercetin and luteolin supplements in target tissues against nicotine toxicity in young albino rats. Fifty animals were involved in this study which were divided into five groups of ten rats, they were treated as: (1) untreated Control (Cont); (2) Nicotine (Ni) treated (0.75 mg/kg b.w./d, i.p); (3) Nicotine as above with intragastric administration of quercetin (Ni+Qu) (50mg/kg b.w) or (4) with luteolin (50mg/kg b.w) in Group (Ni+Lu), and (5) nicotine with combination of quercetin and luteolin (Ni+Qu+Lu) as described above. All groups were treated for 8 weeks, then their liver and lung tissues were dissected out. Several histological damages were noticed in (Ni) rats such as degeneration changes in hepatocytes, slight congestion of central vein (CV) and cellular infiltration. Nicotine caused drastic changes in lung tissues such as, inflammatory cells aggregation inside and outside the bronchiol artery with mild increase in the thickness of bronchial muscular wall and marked thickening in the alveolar wall. All supplemented groups ameliorated the damage that induced by nicotine injection in both liver and lung tissues. In liver tissues, the quercetin (Ni+Qu) supplemented rats showed the better improvement nearby normal hepatocytes than the other groups, while in lung tissues, the luteolin supplemented rats had better recovery than the other treatments. These observations suggested that the intake of quercetin and luteolin as supplements may be useful in combating tissue injury that is a result of nicotine toxicity.