Hepatoprotective Effect of Vitamin E

Abstract

Drugs and some chemical agents are known to induce hepatotoxicity in humans which is of great concern to clinicians. Chemical agents are been screen daily for their hepatoprotective properties. Among these chemical agents is vitamin E which has drawn wide attention due to it reported hepatoprotective property as reported by researchers. This study collected and evaluated reports to ascertain the hepatoprotective effect of vitamin E. A comprehensive literature review on the hepatoprotective property of vitamin E in humans and animals was performed. In this review it was observed that vitamin E exhibited high hepatoprotective effect in animals but with conflicting reports in humans. In humans vitamin E was reported to be beneficial in non alcoholic steatohepatitis, in obese children with non fatty alcoholic liver disease, hepatitis B, hepatitis C and haemochromatosis. In animals it was reported to normalized hepatotoxicity induced by drugs, and some chemical agents including heavy metals. Vitamin E exhibited hepatoprotective effect and decreased oxidative stress in the liver manifested through decrease in microsomal lipid peroxidation, liver fibrosis, tumor necrosis factor, inflammation and hepatic porphyrin. It normalized levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum bilirubin, glutathione superoxide dimutase, lactose dehydrogenase, malondialdehyde and improved histopathological changes in the liver induced by chemical agents. Hepatoprotective property of vitamin E is attributed to it antioxidant property buried in it structure. Structurally, the side chain in the 2-position facilitates the incorporation and retention of vitamin E in biomembranes, so that the 6-position is optimal for scavenging free radicals and terminating lipid peroxidation. Furthermore, it antioxidant effect is exhibited through protection of poly unsaturated fatty acid from oxidation by reactive oxygen species, stabilization of membrane and breaking of antioxidant chains that prevent Reactive Oxygen Species damage to membranes. Vitamin E exhibited hepatoprotective effect in animals. It hepatoprotective effect in humans leaves more room for evaluation due to some discrepancies in report.

Effects Study of Nigella Sativa, Its Oil and Their Combination With Vitamin E on Oxidative Stress in Rats

“…Moreover, supplementation of diet with vitamin E protected sperm DNA from oxidative stress of free radicals (Jedlinska et al, 2006) in rats and increased the activity of antioxidant enzymes involved in the removal of ROS generated by cell metabolism (Caetano et al, 2013). In addition to Adikwu and Nelson (2013) reported that vitamin E exhibited hepatoprotective effect and decreased oxidative stress in the liver manifested through decrease in microsomal lipid peroxidation. It normalized levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum bilirubin, glutathione superoxide dimutase, lactose dehydrogenase, malondialdehyde and improved histopathological changes in the liver induced by chemical agents.…”

Drug-Induced Liver Injury Caused by Use of Vitamins A and E

“…Витамин E (альфа-токоферол, токотриенол) -жирорастворимый антиоксидант, известный как ингибитор перекисного окисления липидов [24,25]. С учетом данного свойства токоферол рассматривается как протектор при сердечно-сосудистых заболеваниях и используется при ишемической болезни сердца [26].…”

“…Во многих исследованиях продемонстрированы индивидуальные особенности гепатотоксичности аюрведических и китайских трав, зеленого чая, гербалайфа, в том числе витаминов А и E [20][21][22][23]. Жирорастворимые витамины А и E чаще рассматриваются как антиоксиданты, которые тормозят реакции, предупреждающие образование свободных радикалов, повреждающих клеточные мембраны [24][25][26]. Однако на фоне нарушения режима приема или сбоя в гепатобилиарной системе они оказывают токсическое воздействие на печень [25][26][27].…”

“…Структура витамина E делает его высокоэффективным антиоксидантом, он тормозит свободнорадикальные реакции, предупреждает образование перекисей, оказывающих повреждающее воздействие на клеточные мембраны, что обеспечивает функционирование нервной и мышечной систем [22][23][24][25][26][27][28][29][30][31][32][33][34]. Альфа-токоферол, находясь внутри фосфолипидного слоя клеточных мембран, защищает клеточные мембраны от окисления свободными радикалами [24]. Совместно с селеном он тормозит гемолиз эритроцитов, является кофактором некоторых ферментных систем -восстанавливает капиллярное кровообращение и повышает устойчивость тканей к гипоксии [23].…”

Hepatoprotective role of Azadirachta Indica and Vitamin E in acetaminophen induced liver toxicity in Wistar rats

“…For hepatoprotective properties, many chemical agents are screened. Vitamin E is a popular compound, regarded widely because of its documented hepatoprotective effect 14 . Due to this special property, Vitamin E has received extensive attention.…”