Balasubramaniyan Vairappan, Shukla Ruchi, Murugaiyan Gopal, Bhonde Ramchandra Ramesh, Nalini Namasivayam
Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar-608002, Tamilnadu, India.
Biochim Biophys Acta. 2007 Aug;1770(8):1136-44. doi: 10.1016/j.bbagen.2007.04.009. Epub 2007 May 3.
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.
肥胖是肝细胞癌（HCC）合并酒精性肝病（ALD）和隐源性肝硬化的危险因素。瘦素是一种主要由脂肪细胞分泌的16 kDa抗肥胖激素。瘦素在细胞系中对酒精介导作用的影响尚待阐明。因此，我们研究了瘦素对人肝癌细胞系（HepG2）中乙醇诱导的细胞毒性的影响。用瘦素（31.2 nM）、乙醇（500 mM）、乙醇 + 瘦素处理HepG2细胞，未处理的细胞作为对照。处理48小时后，分析细胞活力、凋亡、肿瘤坏死因子 -α分泌反应和氧化损伤。我们的结果表明，浓度为31.2 nM的瘦素可预防乙醇诱导的细胞毒性，MTT和台盼蓝染料排除试验证明了这一点。瘦素还抑制了乙醇诱导的凋亡，这通过[³H]胸苷摄取和使用碘化丙啶（PI）染色的细胞周期分析得到证实。此外，瘦素与乙醇同时处理显示出对乙醇介导的细胞损伤的保护作用，表现为活性氧（ROS）和硫代巴比妥酸反应性物质（TBARS）水平显著降低，活性氮（RNS）、还原型谷胱甘肽（GSH）水平显著升高，超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性升高。此外，瘦素下调了乙醇诱导的HepG²细胞中肿瘤坏死因子 -α（TNF -α）的分泌。我们的结果表明，瘦素与乙醇同时处理可能有助于预防乙醇产生的损伤，这可能具有治疗意义。
