Effects of curcumin in intestinal fibrosis of rats and its mechanism / 中华消化杂志

ABSTRACT

Objective To investigate the anti-fibrotic effects of curcumin in trinitrobenzene sulphonic acid (TNBS) induced intestinal fibrosis in rats and its mechanism. Methods Forty SD rats were randomly divided into model group, treatment group, control group and normal group with 10each. Except the normal group, the other three groups were given 10, 15, 20, 25 and 30 mg of TNBS enema on the 1st, 8 th, 15th, 22nd and 29th days,respectively. The rats in treatment group were intraperitonealy injected with 30 mg/kg of curcumin daily. Control group was injected with 0. 9%NaCl solution and normal group received an equal volume of 50% ethanol enema without any treatment. The damage and fibrosis of colon were detected with HE staining and Masson collagen staining, respectively. The contents of interleukin (IL) -2, tumor necrosis factor (TNF) -α, IL-4 and IL-17 in colon were measured by enzyme-link immunosorbent analysis (ELISA). The expressions of intestinal fibrosis related cytokines such as transforming growth factor (TGF) -β1, connective tissue growth factor (CTGF), Smad3, collagen Ⅰ and collagen Ⅲ mRNA were determined by FQ-PCR.Results The macroscopic and micrpscopic colonic damage scores and collagen area were significantly higher in model group (6.14 ± 1.07, 8. 42 ± 1.40 and 36. 59% ± 4.07%, respectively) and control group (6.17 ± 1.47, 8. 17 ±1.47 and 37.18 %±4.05 %, respectively) than those in normal group (2.13±0.64, 2.25±1.28 and 25.43%±5.39% ,respectively)(P＜0.05). Contents of IL2, TNF-α, IL-17, as well as expressions of intestinal fibrosis related cytokines including TGF-β1, CTGF,Smad3, collagen Ⅰ and Ⅲ mRNA were also higher in model group [(378. 25±29. 90) ng/L,(87.11±23.85) ng/L, (47.80±5.62) ng/L, 4.71%±2.71%,10.33%±6.99%,9.35%±7.32%,1.52% ± 1.11% and 3.04% ±1.33%, respectively] and control group [(410. 06 ± 64.74) ng/L,(100.41±12.59) ng/L, (41.45±2. 12) ng/L, 4. 12%±3.01%,11.46%±4.72%,10. 11%±3.80%,1. 57% ± 1. 35% and 3. 03% ± 3. 53%, respectively] in comparision with normal group [(179.74±20. 73) ng/L, (35. 47±7. 13) ng/L, (14. 48±7. 52) ng/L and 0. 90%± 1. 13%,0.53%±0.47%, 0. 62%±0. 44%, 0. 16%±0. 09% and 0. 18%±0. 10%, respectively] (P＜0.05). While in treatment group, the macroscopic (4.00 ± 1.07 ) and micrpscopic (5. 13 ± 1.46)colonic damage scores, collagen area (30.01%±7.56%), contents of IL-2 [(223.91±28.04) ng/L],TNF-α [(44.19±4. 77) ng/L] and IL-17 [(14.89±4. 31) ng/L], expressions of TGF-β1 (0.85%±0.76%), CTGF (1.56%±1.13%), Smad3 (3.62%±3.03%), collagen Ⅰ (0.40%±0.31%) and Ⅲ (0.60 % ± 1.02 % ) mRNA were much lower than those in model group and control group (P＜0.05 ), but similar to those in normal group (P＞ 0.05 ). Conclusions Curcumin can inhibit intestinal fibrosis caused by excessive "wound-healing" reaction via reducing the overexpression of cytokines in colonic mucosa and attenuating the inflammation of colon.