Chemopreventive effects of selected herbal plants against carbon tetrachloride-mediated oxidative tissue damage in rats

• Auteur principal: Koh, Pei Hoon
• Format: Thèse
• Langue: anglais; anglais
• Publié: 2011
• Sujets: QK1-474.5 General Including geographical distribution
• Accès en ligne: https://eprints.ums.edu.my/id/eprint/42928/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/42928/2/FULLTEXT.pdf

Oxidative damage of biomolecules is implicated in the pathogenesis of various chronic diseases including cancer. This has led to intensive investigation aimed at reducing the extent of such oxidative injury. The present study was aimed to evaluate the antioxidant and chemopreventive effects of selected herbal plants against carbon tetrachloride (CCI4)-mediated oxidative tissue damage in rats. Herbal plants viz Aloe vera, Andrographis paniculata, Cymbopogon citratus and Morinda citrifolia were selected and evaluated for their total phenolic and 2,2-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. Based on the results of in vitro studies, A. paniculata and C. citratus were selected further for in vivo studies due to their higher total phenolics and antioxidant activity. Rats were pretreated with ethanolic extract of A. paniculata and C. citratus accordingly to the selected doses (100 mg/kg b.w., 200 mg/kg b.w. and 300 mg/kg b.w.) for 14 days followed by two dosage of CCI4 (1.2 ml/kg b.w.) via oral (gavage) on days 13 and 14. All of these animals were sacrificed 24 hours after the last dose of CCI4 or saline. Blood, liver and kidney tissues were taken quickly for biochemical and histopathological studies to assess the derangement in the functioning of liver and kidneys. Challenge of CCI4 induced oxidative stress both in the liver and kidneys, as evident from augmentation in lipid peroxidation (TBARS) which was accompanied by a decreased in antioxidant enzymes activities and depletion of glutathione reduced level. Parallel to these changes, CCI4 enhanced hepatic damage as evidenced by a sharp increased in serum transaminases. However, blood urea nitrogen and serum creatinine were not elevated significantly. Additionally, serum biochemistry oxidative stress markers were consistent with the hepatic and renal histopathological studies. In liver, most of these changes were significantly alleviated by pretreatment of animals with 300 mg/kg b.w. A. paniculata and 200 mg/kg b.w. C. citratus. The ability of A. paniculata and C. citratus to scavenge the DPPH radical was determined and had an ECso value of 583.60 and 994.77 µg/ml respectively. In addition, the antioxidant activity was closely related to the total phenolic content as evident by A. paniculata and C. citratus showing the value of 65.37 and 30.74 mg GAE/g of extract. In contrast, the changes in the kidney were not significantly alleviated by the pretreatment with A. paniculata and C. citratus extracts. Present results indicate that the hepatoprotective effects of A. paniculata and C. citratus might be ascribable to its antioxidant and free radical scavenging properties. We concluded that A. paniculata and C. citratus could be used as hepatoprotective agents and possess the potential to be used to treat or prevent degenerative diseases where oxidative stress is implicated.