Coffee and caffeine intake reduces risk of ulcerative colitis: a case-control study in Japan.

BACKGROUND AND AIM: Although diet is one of the potential environmental factors affecting ulcerative colitis (UC), evidence is not sufficient to draw definitive conclusions. This Japanese case-control study examined the association between the consumption of coffee, other caffeine-containing beverages and food, and total caffeine and the risk of UC. METHODS: The study involved 384 UC cases and 665 control subjects. Intake of coffee, decaffeinated coffee, black tea, green tea, oolong tea, carbonated soft drinks, and chocolate snacks was measured with a semiquantitative food-frequency questionnaire. Adjustments were made for sex, age, pack-years of smoking, alcohol consumption, history of appendicitis, family history of UC, education level, body mass index, and intake of vitamin C, retinol, and total energy. RESULTS: Higher consumption of coffee and carbonated soft drinks was associated with a reduced risk of UC with a significant dose-response relationship (P for trend for coffee and carbonated soft drinks were <0.0001 and 0.01, respectively), whereas higher consumption of chocolate snacks was significantly associated with an increased risk of UC. No association was observed between consumption of decaffeinated coffee, black tea, green tea, or oolong tea and the risk of UC. Total caffeine intake was inversely associated with the risk of UC; the adjusted odds ratio between extreme quartiles was 0.44 (95% confidence interval: 0.29-0.67; P for trend <0.0001). CONCLUSIONS: We confirmed that intake of coffee and caffeine is also associated with a reduced risk of UC in Japan where people consume relatively low quantities of coffee compared with Western countries.

Simvastatin attenuates intestinal fibrosis independent of the anti-inflammatory effect by promoting fibroblast/myofibroblast apoptosis in the regeneration/healing process from TNBS-induced colitis.

BACKGROUND: Intestinal deformity and stenosis are induced by fibrosis during the process healing of intestinal chronic inflammation in inflammatory bowel disease (IBD). Potent anti-inflammatory treatment of patients with Crohn's disease (CD) may induce fibrous stenosis, and this is often difficult to treat in clinical practice. Therefore, it is necessary to develop a treatment strategy that concomitantly exhibits repair/regenerative and anti-fibrotic effects, in addition to the current anti-inflammatory effect, for the treatment of inflammatory bowel diseases. However, the relationship between the course of inflammatory activity and the healing process and fibrogenesis has not been elucidated; although the complex involvement of various factors in the mechanism of biological fibrosis has been investigated. Simvastatin (SIMV), an HMG-CoA reductase inhibitor, exhibits anti-inflammatory and anti-fibrotic effects. The current study established a model of the regeneration/healing process from TNBS-induced colitis and investigated the anti-inflammatory and anti-fibrotic effects of SIMV. SUBJECTS AND METHODS: Four groups of TNBS-induced colitis model were prepared using male SJL/J mice: A: Normal control group, B: control group, and C and D: treatment groups. The mucosal healing process was classified into three phases (an early phase: inflammation period, a mid-phase: regeneration promoting period, and a late phase: regeneration-converging period), and inflammation, the expression of fibrosis-related growth factors, and induction of apoptosis of fibrosis-related cells were compared in each period. RESULTS: (1) The clinical findings showed that SIMV showed anti-inflammatory effects with body weight gain and improvement of epithelial injury in the late phase. Histological (macroscopic/microscopic) improvement was noted in the mid- and late phases. The inflammatory cytokine (TNF-α) level significantly decreased in the mid- and late phases in the high-dose treatment group. (2) SIMV also had anti-fibrotic effects characterized by a dose-dependent decrease in the level of a fibrosis-related growth factor (CTGF) in the early and mid-phases, irrespective of inflammation or changes in the TGF-ß(1) level. Dose-dependent induction of apoptosis was noted in both fibroblasts and myofibroblasts from a relatively early stage. CONCLUSIONS: The results suggested that SIMV induces anti-fibrotic activity that is not directly involved in the anti-inflammatory effect from a relatively early stage the healing process of TNBS-induced colitis.

R-etodolac induces E-cadherin and suppresses colitis-related mouse colon tumorigenesis.

Colorectal cancer is one of the most serious complications of ulcerative colitis (UC), and the risk of UC-associated neoplasia increases as the region and duration of the disease increase. Selective cyclooxygenase (COX)-2 inhibitors effectively diminish carcinogenesis in a murine UC model. However, this may exacerbate colitis. The selective COX-2 inhibitor etodolac is marketed as a racemic mixture of the R- and S-enantiomers. The biochemical and pharmacological effects of etodolac are caused by the S-enantiomer, while the R-enantiomer lacks COX-inhibitory activity. In this study, we evaluated the effect of R-etodolac on colitis-related mouse colon tumorigenesis. The mice received 1,2-dimethlhydrazine (DMH), and then chronic colitis was induced by administration of two cycles of DSS (each cycle: 3% DSS for 7 days followed by distilled water for 14 days). The mice were sacrificed 28 days after the completion of both cycles. Mice were divided into the following groups: group A served as a disease control; group B received a low (2-mg/kg) dose of R-etodolac every 3 days during the entire period; group C received a high (10-mg/kg) dose of R-etodolac on the same schedule as group B; and group D served as a normal control. Administration of R-etodolac decreased the disease activity index during the DSS administration cycle. The mean number of tumors was 17.8, 15.2, 6.0, and 0 in groups A-D, respectively. In group C, R-etodolac significantly suppressed the occurrence of neoplasia (p<0.05). Although R-etodolac treatment did not affect COX-2 expression, it significantly enhanced expression of E-cadherin in both neoplastic lesions and background mucosa (i.e., lesion-free colon). Thus, administration of R-etodolac exerts a suppressive effect on the development of neoplasia in a murine model of DSS-induced colitis without exacerbation of the colitis. These results suggest that R-etodolac could be useful in the prevention of UC-associated neoplasia.