葡萄果皮提取物对砷致小鼠小肠毒性的缓解作用

Mitigative Effect of Grape Skin Extract on Arsenic-induced Small Intestinal Toxicity in a Mouse Model

目的:探究砷摄入对小肠的毒性及葡萄果皮提取物(grape skin extract,GSE)的干预效应。方法:模拟人类饮水砷暴露,小鼠饮用浓度10 mg/L的砷溶液56 d,建立小鼠砷中毒模型,并用不同浓度GSE隔天灌胃干预(150 mg/kg bw和300 mg/kg bw);取小鼠小肠组织,显微镜观察组织形态结构;试剂盒法检测还原型谷胱甘肽(glutathione,GSH)、丙二醛(malondialdehyde,MDA)和H_(2)O_(2)含量,及总超氧化物歧化酶(total superoxide dismutase,T-SOD)活性;qRT-PCR检测紧密连接基因和炎症通路IL-6/JAK2/STAT-3基因表达水平。结果:砷染毒后,小鼠小肠绒毛变短、排列紊乱,黏膜固有层及黏膜下层大量炎细胞浸润;小肠组织的GSH含量和TSOD活性分别降低17.1%和25.2%,MDA和H_(2)O_(2)含量分别增加68.8%和54.3%(P<0.05);细胞紧密连接基因ZO-1、ZO-2、occludin、claudin-1和claudin-7显著下调表达(P<0.05);炎症通路IL-6/JAK2/STAT-3基因转录水平显著增高(P<0.05)。GSE高浓度干预组(300 mg/kg bw),小肠黏膜损伤减轻,肠绒毛趋于正常,炎症浸润减轻;与砷染毒组比较,GSH含量增加17.9%、T-SOD活性升高14.3%、MDA和H_(2)O_(2)含量分别减少33.8%和25.4%(P<0.05);紧密连接基因显著上调表达(P<0.05);炎症通路IL-6/JAK2/STAT-3基因转录显著降低(P<0.05)。GSE低浓度干预(150 mg/kg bw)对砷毒性有一定的缓解作用,但差异不显著,无统计学意义(P>0.05)。结论:GSE通过抑制砷暴露诱导的小肠组织氧化应激、炎症反应及功能基因转录下调,缓解砷的小肠毒性,对机体具有保护作用。

Objective:To investigate the arsenic-induced small intestinal toxicity and the protective effect of grape skin extract(GSE)against arsenic toxicity.Methods:The small intestinal toxicity was induced by 10 mg/L arsenic via drinking water for 56 days,and was intervened with GSE(150 mg/kg bw and 300 mg/kg bw)by gavage every other day in mice.Small intestine tissue samples of mice were collected and observed by microscope.Glutathione(GSH),malondialdehyde(MDA)and H_(2)O_(2)contents,as well as total superoxide dismutase(T-SOD)were determined by using commercial kits.qRT-PCR was used to detect expression levels of the tight junction genes and the inflammatory pathway IL-6/JAK2/STAT-3 genes.Results:The results showed that 56 days exposure to 10 mg/L arsenic via drinking water resulted in shortened and disordered intestinal villi,with large numbers of inflammatory cells infiltrating the mucosa propria and submucosa.GSH content and T-SOD activity decreased by 17.1%and 25.2%,while MDA and H_(2)O_(2)contents increased by 68.8%and 54.3%,respectively(P<0.05)in the small intestinal tissue of arsenic-treated mice.The mRNA levels of IL-6,JAK2 and STAT-3 were upregulated in the small intestinal tissue of mice exposed to arsenic(P<0.05).Meanwhilethe mRNA levels of the ZO-1,ZO-2,occludin,claudin1 and claudin7 genes,which encode the key components of tight junction(TJ)complexes,were downregulated(P<0.05).However,the application of GSE(300 mg/kg bw)significantly alleviated the damage and inflammatory infiltration in small intestine.Compare to the As group,GSH content and T-SOD activity increased by 17.9%and 14.3%.MDA and H_(2)O_(2)contents decreased by 33.8%and 25.4%(P<0.05).Arsenic-mediated gene expression in the IL-6/JAK2/STAT3 pathway was down-regulated(P<0.05).Moreover,the arsenic-induced down-regulation of TJ genes were markedly relieved in the As+GSE(300 mg/kg bw)group(P<0.05).The As+GSE(150 mg/kg bw)group had a certain alleviating effect on arsenic toxicity,but the difference had no statistical significance(P>0.05).Conclusion:The application of GSE provides significant protection against arsenic-induced small intestinal toxicity by attenuating the oxidative stress and inflammatory responses,and inhibiting the down-regulation of some functional genes.