不同比例ω-3/ω-6多不饱和脂肪酸对大鼠慢性结肠炎模型的影响

Effects of different ratios of ω-3/ω-6 polyunsaturated fatty acids on chronic colitis in rats

目的研究不同比例ω-3/ω-6多不饱和脂肪酸对葡聚糖硫酸钠(dextran sulfate sodium,DSS)诱导大鼠慢性结肠炎的影响。方法选取40只4周龄雄性SPF级SD大鼠,随机分为A^E共5组。A、E组予普通饲料喂养,B、C、D组大鼠分别予ω-3/ω-6 PUFA 1∶1、1∶3及1∶30的改造饲料喂养,共6周。随后除E组外,其余4组予3%DSS水溶液自由饮用7 d后,改为普通水饮用12 d,此为1个循环。如此反复3个循环,制造慢性结肠炎动物模型。记录各组大鼠体质量、粪便、一般情况,比较各组大鼠结肠炎症状积分、组织病理损伤积分和血清及结肠组织中PGE2、LTB4、TNF-α含量。结果ω-3/ω-6 PUFA 1∶1组大鼠可以降低DSS诱导的结肠炎大鼠的炎症症状总积分(P<0.05)、组织病理损伤积分(P<0.05),血清及组织中PGE2、LTB4、血清TNF-α均有所下降(P<0.05)。ω-3/ω-6 PUFA 1∶3组部分改善DSS诱导大鼠结肠炎,使DSS诱导慢性结肠炎大鼠组织中LTB4及血清中PGE2降低。ω-3/ω-6 PUFA 1∶30使DSS诱导慢性结肠炎大鼠炎症症状积分升高(P<0.001),加重组织病理损伤积分(P<0.05),组织中TNF-α含量升高(P<0.05)。结论含有高比例ω-3/ω-6 PUFA的饲料可以改善大鼠慢性结肠炎症状,比例1∶1效果优于1∶3,饲料中过高的ω-6 PUFA可以加重大鼠慢性结肠炎。因此推测将炎症性肠病患者膳食中ω-3/ω-6 PUFA比例提高可能使患者获益。

Objective To investigate the effect of different ratios of ω3/ω-6 polyunsaturated fatty acids （PUFA） on colitis induced by dextran sulfate sodium （DSS） in rats. Methods Forty male SD rats were randomly divided into five groups （n=8）. Group A： pure DSS induced colitis with normal diets; group B, group C and group D： diets of ω-3/ω-6 PUFA with the ratio of 1 ： 1, 1 ： 3 and 1 ： 30; Group E normal controlled group. After six weeks of different diets, colitis were induced by drinking the 3% DSS freely for 7 days, and then drinking water for 12 days in all groups except of group E. The phase above was recycled by twice, and the chronic colitis rats model were established. All the rats were sacrificed when the last cycle was done. Inflammatory severity scoring and histological damage scoring were evaluated. And the level of PGE2, LTB4, TNF- o~ in serum and colon were measured using ELISA. Results The overall inflammatory severity scoring of DSS induced colitis （P 〈 0.05）, histological damage scoring （P 〈 0.05） were lowered and the PGE2 in colon and serum, LTB4 in colon and TNF- et in serum （P 〈 0.05） were lessened in rats of group ω-3/ω-6 PUFA 1 ： 1. The imflammation of colitis was improved in some aspects and the LTB4 in colon and PGE2 in serum （P 〈 0.05） were decreased in rats of group ω-3/ω-6 PUFA1 ： 3. The colitis was deteriorated and the inflammatory severity scoring （P 〈 0.05）, histological damage scoring （P 〈 0.05） and TNF- ot in colon were increased （P 〈 0.05） in rats of group ω-3/ω-6 PUFA 1 ： 30. Conclusion Diets of high ratio of ω-3 to ω-6 PUFA improves the chronic colitis of rats, and the efficiency of the ratio of 1 ： 1 is better than 1 ： 3. However, high ratio of ω-6 PUFA （1 ： 30） deteriorates the colitis induced by DSS. It suggests that high ratio of ω-3 to ω-6 PUFA can improve the condition of patients with inflammtory bowel disease.