Nassar Ayoub Abdellatif Omar^{1, 2}, Amal Nor Edeen Ahmad Allithy^{3, 4}, Firas Mahmoud Faleh⁵, Reham A. Mariah^{6, 7}, Mongi Mohamed Ahmed Ayat^{7, 8}, Sherine Ragab Shafik⁹, Samah A. Elshweikh¹⁰, Hussam Baghdadi⁷, Salah Mohamed El Sayed^{7, 11,}

Nicotine is the most abundant component in cigarette smoking and is involved in the pathogenesis of lung cancer and increases the risk of developing hepatocellular carcinoma and liver cirrhosis. Prevention of nicotine-induced lung cancer and liver damage may be achieved via decreasing nicotine-induced pathological effects. Nicotine is metabolized in the liver. Natural diet contains a variety of compounds e.g. apple cider vinegar (ACV) that exhibits protective effects against different toxins. This study aims to investigate the effects of nicotine on the liver using morphometrical, histopathological and biochemical parameters and study the protective effect of ACV against toxicity of nicotine. Three groups of the male albino rat were used: untreated control group, nicotine treated group (4 mg/kg/day) while the third group received both ACV (2ml/kg/day) and nicotine (4 mg/kg/day). Treatment was given for 30 days. There was a significant increase in the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) together with a damage and degeneration in the liver tissues of the nicotine treated groups. ACV administration to nicotine-treated rats showed near normal liver biochemical markers with reduction in the tissue damage associated with the nicotine administration. ACV administration to nicotine-treated rat ameliorated the decrease in the size of the hepatocytes nuclei. These results, along with previous observations, suggest that ACV may be useful in combating tissue injury resulting from nicotine toxicity. In prophetic medicine, Prophet Muhammad peace be upon him strongly recommended eating vinegar in the prophetic hadeeth: "vinegar is the best edible". Conclusion: These finding confirm that chronic nicotine administration causes harmful effects to the liver and suggest that ACV may be useful in combating tissue injury resulting from nicotine toxicity. Hence, the intake of ACV might suppress the toxicity and mutagenic activity of nicotine. ACV may protect against nicotine-induced carcinogenesis.

nicotine exposure, apple cider vinegar, liver, hepatotoxicity, rats