Sinha Mahua, Manna Prasenjit, Sil Parames C
Department of Chemistry, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata 700 009, India.
Toxicol In Vitro. 2007 Dec;21(8):1419-28. doi: 10.1016/j.tiv.2007.05.010. Epub 2007 Jun 2.
Arsenic is a potent environmental toxin. Present study has been designed to evaluate the protective role of taurine (2-aminoethanesulfonic acid) against arsenic induced cytotoxicity in murine hepatocytes. Sodium arsenite (NaAsO(2)) was chosen as the source of arsenic. Incubation of hepatocytes with the toxin (1 mM) for 2 h reduced the cell viability as well as intra-cellular antioxidant power. Increased activities of alanine transaminase (ALT) and alkaline phosphatase (ALP) due to toxin exposure confirmed membrane damage. Toxin treatment caused reduction in the activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx). In addition, the same treatment reduced the level of glutathione (GSH), elevated the level of oxidized glutathione (GSSG) and increased the extent of lipid peroxidation. Incubation of hepatocytes with taurine, both prior to and in combination with NaAsO(2), attenuated the extent of lipid peroxidation and enhanced the activities of enzymatic as well as non enzymatic antioxidants. Besides, taurine administration normalized the arsenic-induced enhanced levels of the marker enzymes ALT and ALP in hepatocytes. The cytoprotective activity of taurine against arsenic poisoning was found to be comparable to that of a known antioxidant, vitamin C. Combining all, the results suggest that taurine protects mouse hepatocytes against arsenic induced cytotoxicity.
砷是一种强效的环境毒素。本研究旨在评估牛磺酸(2-氨基乙磺酸)对砷诱导的小鼠肝细胞毒性的保护作用。选择亚砷酸钠(NaAsO₂)作为砷的来源。将肝细胞与毒素(1 mM)孵育2小时会降低细胞活力以及细胞内抗氧化能力。由于毒素暴露导致丙氨酸转氨酶(ALT)和碱性磷酸酶(ALP)活性增加,证实了细胞膜受损。毒素处理导致抗氧化酶超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽-S-转移酶(GST)、谷胱甘肽还原酶(GR)和谷胱甘肽过氧化物酶(GPx)的活性降低。此外,相同处理降低了谷胱甘肽(GSH)水平,提高了氧化型谷胱甘肽(GSSG)水平,并增加了脂质过氧化程度。在与NaAsO₂孵育之前和同时用牛磺酸孵育肝细胞,可减轻脂质过氧化程度,并增强酶促和非酶促抗氧化剂的活性。此外,给予牛磺酸可使砷诱导的肝细胞中标志物酶ALT和ALP水平升高恢复正常。发现牛磺酸对砷中毒的细胞保护活性与已知抗氧化剂维生素C相当。综合来看,结果表明牛磺酸可保护小鼠肝细胞免受砷诱导的细胞毒性。