Department of Biochemistry and Tumor Marker Oncology Research unit, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt.
Environ Toxicol Pharmacol. 2005 Feb;19(2):371-7. doi: 10.1016/j.etap.2004.09.004.
Acrylonitrile (ACN), an environmental toxic pollutant, has been detected in drinking water, food products and occupational environment. The objective of the present work was to investigate the cytotoxic effects as well as the oxidative stress induced by ACN in cultured rat colonocytes. Colonocytes were exposed in vitro to different concentrations of ACN (0.1-2.0mM) for 60min. Also, colonocytes were incubated with ACN (1.0mM) for different time intervals extending to 180min. Cytotoxicity was determined by assessing cell viability and lactate dehydrogenase (LDH) release. Oxidative stress was assessed by determining reduced glutathione (GSH) level and lipid peroxidation as indicated by thiobarbituric acid reactive substances (TBARS) production. Exposure of colonocytes to ACN (1.0mM) for 60min caused nearly a 50% decrease in cell viability and induced a 2.5-fold increase of LDH leakage. In the same experiment, ACN caused a significant decrease in cellular GSH content as well as a significant enhancement of TBARS accumulation. These toxic responses to ACN were dependent on both concentration and duration of exposure to ACN. There was a good correlation between LDH release and TBARS formation (r(2)=0.97, p<0.05). Treatment of colonocytes with GSH, N-acetyl-l-cysteine (NAC) or dithiothreitol (DDT) prior to exposure to ACN afforded different degrees of protection as indicated by significant decrease in the LDH leakage and TBARS formation as compared to ACN alone-treated cells. Also, pretreatment of colonocytes with the antioxidant enzyme superoxide dismutase (SOD) or catalase (CAT) significantly inhibited LDH leakage and TBARS production. Preincubation with dimethyl sulfoxide (DMSO), a hydroxyl radical scavenger or desferroxiamine (DFO), an iron chelator, diminished ACN-induced LDH leakage and TBARS generation. Our results suggest that ACN has a potential cytotoxic effect in rat colonocytes; and thiol group-donors, antioxidant enzymes, hydroxyl radical scavengers and iron chelators can play an important role against ACN-induced colonotoxicity.
丙烯腈（ACN）是一种环境毒物污染物，已在饮用水、食品和职业环境中检测到。本工作的目的是研究丙烯腈在培养的大鼠结肠细胞中引起的细胞毒性作用和氧化应激。结肠细胞在体外暴露于不同浓度的丙烯腈（0.1-2.0mM）60 分钟。此外，结肠细胞用丙烯腈（1.0mM）孵育不同的时间间隔，延长至 180 分钟。通过评估细胞活力和乳酸脱氢酶（LDH）释放来确定细胞毒性。通过测定还原型谷胱甘肽（GSH）水平和丙二醛（TBARS）产生所指示的脂质过氧化来评估氧化应激。将结肠细胞暴露于丙烯腈（1.0mM）60 分钟导致细胞活力降低近 50%，并诱导 LDH 漏出增加 2.5 倍。在相同的实验中，丙烯腈导致细胞内 GSH 含量显著降低，TBARS 积累显著增加。这些对丙烯腈的毒性反应取决于丙烯腈的浓度和暴露时间。LDH 释放与 TBARS 形成之间存在良好的相关性（r²=0.97，p<0.05）。在用丙烯腈处理结肠细胞之前用谷胱甘肽、N-乙酰-L-半胱氨酸（NAC）或二硫苏糖醇（DDT）处理结肠细胞，与单独用丙烯腈处理的细胞相比，LDH 漏出和 TBARS 形成显著减少，提供了不同程度的保护。此外，用抗氧化酶超氧化物歧化酶（SOD）或过氧化氢酶（CAT）预处理结肠细胞可显著抑制 LDH 漏出和 TBARS 产生。用二甲基亚砜（DMSO），一种羟基自由基清除剂或去铁胺（DFO），一种铁螯合剂预处理，可减少丙烯腈诱导的 LDH 漏出和 TBARS 生成。我们的结果表明，丙烯腈对大鼠结肠细胞具有潜在的细胞毒性作用；巯基供体、抗氧化酶、羟基自由基清除剂和铁螯合剂可在对抗丙烯腈引起的结肠毒性方面发挥重要作用。
