美洲大蠊提取物Ento-A对湿热型溃疡性结肠炎模型大鼠的改善作用研究

目的:研究美洲大蠊提取物Ento-A对湿热型溃疡性结肠炎(UC)模型大鼠的改善作用。方法:将70只大鼠随机分为正常对照组(n=8)和造模组(n=62),造模组大鼠采用高糖高脂、辛辣饮食联合2,4,6-三硝基苯磺酸灌肠法复制湿热型UC动物模型。将造模成功的48只大鼠随机分为模型对照组、美沙拉嗪组(300 mg/kg)、肠炎宁(300 mg/kg)和Ento-A低、中、高剂量组(50、100、200 mg/kg,以提取物计),每组8只。正常对照组和模型对照组大鼠灌胃生理盐水,其余各组大鼠灌胃相应药物,每天1次,连续给药14 d。末次给药后,对大鼠疾病活动指数(DAI)、结肠黏膜损伤指数(CMDI)及病理组织学(HS)进行评分,测定大鼠脾指数、肝指数和结肠指数,并采用酶联免疫吸附法测定大鼠血清中白细胞介素8(IL-8)、IL-17、超氧化物歧化酶(SOD)、丙二醛(MDA)水平和结肠组织中IL-2、前列腺素E2(PGE2)、髓过氧化物酶(MPO)水平。结果:与正常对照组比较,模型对照组大鼠DAI评分、CMDI评分、HS评分、结肠指数以及血清中IL-8、IL-17、MDA水平和结肠组织中MPO、PGE2水平显著升高(P<0.01),血清中SOD水平和结肠组织中IL-2水平显著降低(P<0.01)。与模型对照组比较,Ento-A高剂量组大鼠DAI评分、CMDI评分及血清中IL-17、MDA水平和结肠组织中PGE2水平显著降低(P<0.05或P<0.01),血清中SOD水平和结肠组织中IL-2水平显著升高(P<0.01);Ento-A中剂量组大鼠CMDI评分、HS评分以及血清中IL-8、IL-17、MDA水平和结肠组织中PGE2、MPO水平显著降低(P<0.05或P<0.01),结肠组织中IL-2水平显著升高(P<0.01);Ento-A低剂量组大鼠HS评分以及血清中IL-17、MDA水平和结肠组织中MPO、PGE2水平显著降低(P<0.05或P<0.01),血清中IL-2水平显著升高(P<0.01)。结论:美洲大蠊提取物Ento-A可能通过调节免疫系统平衡、减少炎症损伤,发挥其对湿热型UC模型大鼠的改善作用。

Study on the Improvement Effects of Periplaneta americana Extract Ento-A on Rats with Damp-heat Ulcerative Colitis

OBJECTIVE:To study the improvement effect of Periplaneta americana extract Ento-A on damp-heat ulcerative colitis(UC)model rats.METHODS:Totally 70 rats were randomly divided into normal control group(n=8)and modeling group(n=62).The damp-heat UC model was induced in modeling group by high sugar,high fat,spicy diet combined with 2,4,6-trinitrobenzene sulfonic acid enema.48 model rats were randomly divided into model control group,mesalazine group(300 mg/kg),Changyanning group(300 mg/kg)and Ento-A low-dose,medium-dose and high-dose(50,100,200 mg/kg,calculated by the extract),with 8 rats in each group.Normal control group and model control group were given normal saline intrsgastrically,and other groups were given relevant medicine intragastrically,once a day,for consecutive 14 days.After last administration,disease activity index(DAI),colonic mucosal injury index(CMDI)and histopathological score(HS)of rats were determined.The spleen index,liver index and colon index in rats were determined.The serum levels of IL-8,IL-17,SOD and MDA,colonic levels of IL-2,PGE2 and MPO were detected by ELISA.RESULTS:Compared with normal control group,the DAI score,CMDI score,HS score,colonic index,the serum levels of IL-8,IL-17 and MDA,colonic levels of MPO and PGE2 were increased significantly(P<0.01);serum level of SOD and colonic level of IL-2 were decreased significantly(P<0.01).Compared with model control group,DAI score,CMDI score,serum levels of IL-17 and MDA,colonic levels of PGE2 were decreased significantly in Ento-A high-dose groups(P<0.05 or P<0.01),while serum level of SOD and colonic level of IL-2 were increased significantly(P<0.01).CMDI score and HS score,serum levels of IL-8,IL-17 and MDA,colonic levels of PGE2 and MPO were decreased significantly in Ento-A medium-dose group(P<0.05 or P<0.01),while colonic level of IL-2 was increased significantly(P<0.01).HS score,serum levels of IL-17 and MDA,colonic levels of MPO and PGE2 were decreased significantly in Ento-A low-dose group(P<0.05 or P<0.01),while serum level of IL-2 was increased significantly(P<0.01).CONCLUSIONS:P.americana extract Ento-A may play improvement effect on damp-heat UC rats by regulating immune system balance and reducing inflammatory damage.