title: Mouse recombinant leptin protects human hepatoma HepG2 against apoptosis, TNF-alpha response and oxidative stress induced by the hepatotoxin-ethanol.
abstract: Obesity is a risk factor for hepatocellular carcinoma (HCC) complicated with alcoholic liver disease (ALD) and cryptogenic cirrhosis. Leptin is a 16-kDa antiobesity hormone secreted mainly by adipocytes. The role of leptin on alcohol-mediated effects in cell line is yet to be unraveled. Therefore, we investigated the effect of leptin against ethanol-elicited cytoxicity in human hepatoma cell lines (HepG2). HepG2 cells were treated with leptin (31.2 nM), ethanol (500 mM), ethanol+leptin and untreated cells served as control. 48 h after treatment, cell viability, apoptosis, TNF-alpha secretory response and oxidative damage were analysed. Our results suggest that leptin at a concentration of 31.2 nM prevents ethanol elicited cytotoxicity as evidenced by MTT and trypan blue dye exclusion assay. Leptin also inhibited ethanol-induced apoptosis, which was confirmed by [(3)H] thymidine uptake and cell cycle analysis using propidium iodide (PI) staining. Further, simultaneous leptin treatment along with ethanol showed protection against ethanol mediated cellular damage as indicated by significantly decreased levels of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) and significantly increased levels of reactive nitrogen species (RNS), reduced glutathione (GSH) and elevated activities of superoxide dismutase (SOD) and catalase (CAT). In addition, leptin downregulated the secretion of tumor necrosis factor-alpha (TNF-alpha) by ethanol-induced HepG2 cells. Our results demonstrate that simultaneous leptin treatment along with ethanol could be useful in preventing the damage produced by ethanol, which might be of therapeutic interest.
authors.affiliation: Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar-608002, Tamilnadu, India.
authors.forename: Vairappan
authors.initials: V
authors.lastname: Balasubramaniyan
authors.forename: Ruchi
authors.initials: R
authors.lastname: Shukla
authors.forename: Gopal
authors.initials: G
authors.lastname: Murugaiyan
authors.forename: Ramchandra Ramesh
authors.initials: RR
authors.lastname: Bhonde
authors.forename: Namasivayam
authors.initials: N
authors.lastname: Nalini
mesh_terms: D000293:Adolescent; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000378:metabolism; D002374:Catalase / Q000032:analysis; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004347:Drug Interactions; D000431:Ethanol / Q000633:toxicity; D005978:Glutathione / Q000032:analysis; D006801:Humans; D020738:Leptin / Q000235:genetics / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008113:Liver Neoplasms / Q000378:metabolism; D008297:Male; D051379:Mice; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D018384:Oxidative Stress / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*
chemical_list: D020738:Leptin; D009566:Nitrates; D009573:Nitrites; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D000431:Ethanol; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione