为了探究不同剂量的市售食品级κ-卡拉胶作为添加剂能否诱发机体结肠炎症。对已购卡拉胶样品进行亚型和分子量测定。将72只6周龄的C57BL/6J小鼠随机分为6组，分别给予小鼠普通饲料（NC）和含有0.05%（0.05% CGN）、0.5%（0.5% CGN）、1%（1% CGN）、2.5%（2.5% CGN）和5%（5% CGN）5种不同剂量卡拉胶样品的饲料，持续6周。小鼠处死后测定结肠炎症相关指标。卡拉胶特征分析表明，该样品属于κ型，食品级卡拉胶。动物实验表明，不同剂量卡拉胶干预对小鼠的胸腺指数、脾脏指数、结肠微观结构和结肠长度以及结肠中前列腺素E2（PGE2）的释放量无明显影响（p>0.05）；0.05% CGN、2.5% CGN组小鼠结肠中肿瘤坏死因子-α（TNF-α）的蛋白表达量及髓过氧化物酶（MPO）酶活与对照组相比分别下降了63.14%和29.50%（p<0.05，p<0.01），其余剂量组与对照组相比无显著差异（p>0.05）；除1%CGN组小鼠结肠上皮细胞中Toll样受体4（TLR4）的蛋白表达高于对照组外（66.67%，p<0.05），其余卡拉胶干预组与对照组相比无明显差异（p>0.05）。研究结果表明饲料中添加0.05%~5%的食品级κ-卡拉胶对小鼠无致结肠炎作用。该结果提示，成年人日常摄入卡拉胶加工食品无罹患结肠炎风险。

To investigate whether various dosages of marketed food-grade κ-carrageenan could induce colitis in the organisms, the subtype and molecular weight of purchased carrageenan sample were detected. 72 6-week-old C57BL/6J mice were randomly divided into 6 groups and fed the normal diet (NC), the normal diet mixed with the dosages of 0.05% (0.05% CGN), 0.5% (0.5% CGN), 1% (1% CGN), 2.5% (2.5% CGN) and 5% (5% CGN) of the carrageenan sample for six weeks, respectively. The related colitis markers of mice were measured after sacrifice. The characteristic analysis of carrageenan indicated that the sample belonged to κ type food-grade carrageenan. The animal experiment showed that different dosages of carrageenan intervention had no significant effects on the thymus index, spleen index, colon microstructure and length, and release of prostaglandin E2 (PGE2) in colon (p>0.05). The protein expression of tumor necrosis factor-α (TNF-α) and the activity of myeloperoxidase (MPO) in the colon of 0.05% CGN and 2.5% CGN group mice respectively decreased by 63.14% and 29.50%, compared to the control group (p<0.05, p<0.01). There was no significant difference between the other dosage groups and the control group (p>0.05). The protein expression of Toll-like receptor 4 (TLR4) in colonic epithelium of mice in 1% CGN group was higher than that in control group (66.67%, p<0.05) and there was no significant difference between the other carrageenan intervention groups and the control group (p>0.05). The research results suggested that supplementation of 0.05%~5% food-grade κ-carrageenan in diet had no colitis effect for mice. The results show that the adults who consume carrageenan-processed-food daily are not at risk for colitis.

国家重点研发计划项目（2019YFC1604605）