Inflammatory bowel disease--a radical view

Therapeutic effects of rectal administration of muscovite on experimental colitis in rats

BACKGROUND AND AIMS

The aim of this study was to investigate whether rectal administration of muscovite can ameliorate colonic inflammation in a rat model of experimental colitis, and its possible mechanism.

METHODS

Female Sprague-Dawley (SD) rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis were treated with rectal administration of muscovite or 5-aminosalicylic acid (5-ASA) daily for 14 days. The changes in body weight, macroscopic damage and histologic scores were subsequently evaluated. Gene expression of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), mucin2 (MUC2) and trefoil factor 3 (TFF3) in the colonic tissues was assessed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) while protein levels of TNF-alpha and IL-1beta were detected by ELISA. Mucin2 expression in colonic mucosa was detected by immunohistochemistry. The capacity of muscovite to adsorb cytokines in vitro was determined by the changes in the amount of TNF-alpha, IL-1beta secreted by lipopolysaccharide (LPS)-stimulated THP-1 cells and IL-8 secreted by LPS-stimulated HT-29 cells.

RESULTS

Rectal administration of muscovite improved the loss of body weight, macroscopic and histologic scores of TNBS-induced colitis in a dose-dependent manner. Trinitrobenzene sulfonic acid-induced expression of TNF-alpha and IL-1beta was reduced by muscovite and 5-ASA treatment. Reduction of MUC2 expression in colitis rats was reversed by muscovite and 5-ASA treatment. However, the expression of TFF3 mRNA in colonic mucosa was not affected. In addition, we found muscovite inhibited the expression of TNF-alpha, IL-1beta secreted by THP-1 and IL-8 secreted by HT-29 cells in a dose-dependent manner.

CONCLUSIONS

Our study demonstrated for the first time that rectal administration of muscovite can ameliorate colonic inflammation of TNBS-induced colitis. Further confirmatory studies are needed to prove that muscovite might be a potential therapeutic agent for the treatment of ulcerative colitis.

Non-invasive monitoring of redox status in mice with dextran sodium sulphate-induced colitis

Change of redox status is associated with colitis induced by dextran sodium sulphate (DSS). This study monitored redox status in DSS-induced colitis in mice using in vivo electron spin resonance (ESR) spectroscopy with nitroxyl probes. Colitis was induced in male ICR mice by supplementing their drinking water with 3% DSS for 3, 5 or 7 days. The ESR signal decay rate of carbamoyl-PROXYL administered into the rectum was enhanced by DSS treatment and the enhancement on day 7 was suppressed by membrane-permeable antioxidants, tiron and dimethylsulphoxide and a membrane-impermeable antioxidant, mannitol. The enhancement on day 5 was suppressed by tiron and dimethylsulphoxide, while that on day 3 was inhibited only by tiron. These results suggest that redox change occurs in or around of epithelial cells on day 7, but only intracellularly on day 5, and that redox change such as generation of less reactive radicals occurs only intracellularly on day 3.

Benefit of nicorandil using an immunologic murine model of experimental colitis

Inflammatory bowel disease (IBD) is a chronic inflammatory condition with an unknown etiology. Nicorandil, a potassium channel opener, has been used for many years for the treatment of angina. Recently, it has been shown that nicorandil possesses some novel traits such as anti-apoptotic, gastroprotective, free radical scavenging, and anti-inflammatory properties. Therefore, we set out to examine the possible beneficial effect of nicorandil in a rat model of IBD. Colitis was induced by rectal administration of 2,4,6-trintrobenzene sulphonic acid (TNBS) into rats. Groups of animals used in this study were sham, control, and exposure to dexamethasone, nicorandil, glibenclamid (a pure adenosine triphosphate sensitive potassium channel (KATP) blocker), or nicorandil plus glibenclamid. Drugs were administered by gavage and animals were sacrificed after 7 days. Biochemical markers, including TNF-α and IL-1β, ferric reducing/antioxidant power (FRAP), myeloperoxidase (MPO) activity and thiobarbitoric acid-reactive substance (TBARS), were measured in the homogenate of colonic tissue. Results indicate that nicorandil significantly reduces macroscopic and histological damage induced by TNBS. Nicorandil diminishes MPO activity and levels of TBARS, TNF-∢, and IL-1β in damaged colonic tissue with a concomitant increase in FRAP value (P<0.01). These effects were not reversed by coadministration of glibenclamide. In conclusion, nicorandil is able to ameliorate experimental IBD with a dose in which it does not show any anti-hypertensive effect, and the mechanism of which is partially or totally independent from KATP channels. It is hypothesized that nitric oxide donation and free-radical scavenging properties of nicorandil upregulate endothelial nitric oxide synthase may be responsible for this phenomenon. These findings suggest that nicorandil can be useful in treatment of IBD, although further investigations are needed to elucidate the mechanisms involved.

Effect of Shenqing recipe on the expression of substance P and vasoactive intestine poiypeptide in TNBS-induced rat colitis

AIM: To study the change of intestinal motility in trinitrobenzene sulfonic acid (TNBS)-induced rat colitis and to investigate the mechanism underlying the anti-inflammatory action and regulating the expression of substance P(SP)and vasoactive intestinal Polypeptide (VIP) by Shenqing recipe (SQR).

METHODS: Rats were randomly divided into SQR high dose group, SQR low dose group,5-ASA group, model Ⅰ group, model Ⅱ group and normal group with 10 rats in each group. Rats in model Ⅰ group were killed on day 3, and rats in the other groups were given medicine on day 3, once a day for 7 days. Rats were killed after 7 days' treatment. Histopathological assessment of the colonic mucosa was performed. MPO, MDA and SOD levels in the colonic mucosa were determined by ultraviolet spectrometer. The expression of neurotransmitters including SP and VIP was detected by immunohistochemical staining.

RESULTS: Compared with the normal group, the colonic mucosal levels of MPO and MDA were increased (2.78 ± 0.26 vs 0.56 ± 0.20, 15.14 ± 2.02 vs 7.41 ± 1.19, P < 0.05), while the level of SOD was decreased in the model Ⅰ group (84.15 ± 6.27 vs176.33 ± 12.06, P < 0.05). Compared with model Ⅱ group, the colonic mucosa levels of MPO and MDA were markedly decreased (1.03 ± 0.23, 1.57 ± 0.27, 1.59 ± 0.12 vs 2.03 ± 0.33; 8.30 ± 1.27, 10.09 ± 1.09, 10.46 ± 1.37 vs 14.38 ± 1.84, P< 0.05), and the level of SOD was increased in the SQR high dose group, SQR low dose group and 5-ASA group (190.17 ± 7.71, 178.90 ± 8.59, 176.13 ± 9.50 vs 107.09 ± 6.37, P < 0.05). Compared with the normal group, the expression of VIP and SP of the colonic mucosal was decreased in model Ⅰ group (42 608.00 ± 4823.37 vs 461 570.00 ± 18 227.7; 50 801.90 ± 7698.09 vs 607 333.90 ± 34 166.35, P < 0.05). After treatment, compared with the model Ⅱ group ,the expressions of VIP and SP were up-regulated in SQR high dose group, SQR low dose group and 5-ASA group (302 253.10 ± 11 484.92, 171 014.7 ± 21 993.34, 158 355.10 ± 13 855.66 vs 77 260.26 ± 9375.49; 419 171.36 ± 23 267.98, 279 572.17 ± 26 645.82, 282 438.50 ± 13 236.13 vs 111 838.85 ± 9698.09, all P < 0.05).

CONCLUSION: Our data indicate Shenqing recipe regulates the intestinal motility of SQR possibly through up- regulating the expressions of VIP and SP.

Molecular evidences on the benefit of N-acetylcysteine in experimental colitis

Inflammatory bowel disease (IBD) is a chronic recurrent disease of the digestive tract with an unknown etiology. The aim of this study was to examine the possible protective effects of N-acetylcysteine (NAC) in the mouse model of IBD by measuring specific biomarkers in the colon cells. Colitis was induced by administration of dextran sodium sulfate (DSS) in drinking water (3%) for 7 days. Three doses of NAC (106, 160, and 240 mg/kg) were given after induction of colitis (4 days post DSS) for 4 days by gavage. Lipid peroxides (LP), total antioxidant power (TAP), total thiol molecules (TTM), tumor necrosis factor-α (TNF-α), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT) were measured in the colon homogenate of the treated animals. NAC (160 and 240 mg/kg) significantly decreased LP, TNF-α, NO and increased TTM, SOD, and CAT. The TAP was also increased by NAC (240 mg/kg). It is concluded that moderate to high doses of NAC improves cellular biomarkers of IBD in mice. Further studies should be trialled in humans suffering from two common inflammatory bowel disease called ulcerative colitis and Crohn’s disease.

Ameliorative effects of bombesin and neurotensin on trinitrobenzene sulphonic acid-induced colitis, oxidative damage and apoptosis in rats

AIM: To investigate the effects of bombesin (BBS) and neurotensin (NTS) on apoptosis and colitis in an ulcerative colitis model.

METHODS: In this study, a total of 50 rats were divided equally into 5 groups. In the control group, no colitis induction or drug administration was performed. Colitis was induced in all other groups. Following the induction of colitis, BBS, NTS or both were applied to three groups of rats. The remaining group (colitis group) received no treatment. On the 11th d after induction of colitis and drug treatment, blood samples were collected for TNF-α and IL-6 level studies. Malondialdehyde (MDA), carbonyl, myeloperoxidase (MPO) and caspase-3 activities, as well as histopathological findings, evaluated in colonic tissues.

RESULTS: According to the macroscopic and microscopic findings, the study groups treated with BBS, NTS and BBS + NTS showed significantly lower damage and inflammation compared with the colitis group (macroscopic score, 2.1 ± 0.87, 3.7 ± 0.94 and 2.1 ± 0.87 vs 7.3 ± 0.94; microscopic score, 2.0 ± 0.66, 3.3 ± 0.82 and 1.8 ± 0.63 vs 5.2 ± 0.78, P < 0.01). TNF-α and IL-6 levels were increased significantly in all groups compared with the control group. These increases were significantly smaller in the BBS, NTS and BBS + NTS groups compared with the colitis group (TNF-α levels, 169.69 ± 53.56, 245.86 ± 64.85 and 175.54 ± 42.19 vs 556.44 ± 49.82; IL-6 levels, 443.30 ± 53.99, 612.80 ± 70.39 and 396.80 ± 78.43 vs 1505.90 ± 222.23, P < 0.05). The colonic MPO and MDA levels were significantly lower in control, BBS, NTS and BBS + NTS groups than in the colitis group (MPO levels, 24.36 ± 8.10, 40.51 ± 8.67 and 25.83 ± 6.43 vs 161.47 ± 38.24; MDA levels, 4.70 ± 1.41, 6.55 ± 1.12 and 4.51 ± 0.54 vs 15.60 ± 1.88, P < 0.05). Carbonyl content and caspase-3 levels were higher in the colitis and NTS groups than in control, BBS and BBS + NTS groups (carbonyl levels, 553.99 ± 59.58 and 336.26 ± 35.72 vs 209.76 ± 30.92, 219.76 ± 25.77 and 220.34 ± 36.95; caspase-3 levels, 451.70 ± 68.27 and 216.20 ± 28.17 vs 28.60 ± 6.46, 170.50 ± 32.37 and 166.50 ± 30.95, P < 0.05).

CONCLUSION: The results of this study suggest BBS and NTS, through their anti-inflammatory actions, support the maintenance of colonic integrity and merit consideration as potential agents for ameliorating colonic inflammation.

Aggravation by selective COX-1 and COX-2 inhibitors of dextran sulfate sodium (DSS)-induced colon lesions in rats

We examined the effect of cyclooxygenase (COX) inhibitors on dextran sulfate sodium (DSS)-induced ulcerative colitis in rats and investigated the role of COX isozymes in the pathogenesis of this model. Experimental colitis was induced by treatment with 2.5% DSS in drinking water for 6 days. Indomethacin (a nonselective COX inhibitor), SC-560 (a selective COX-1 inhibitor), or celecoxib (a selective COX-2 inhibitor) was given PO twice daily for 6 days, during the first 3 or last 3 days of the experimental period. Daily treatment with 2.5% DSS for 6 days caused damage to the colon, with a decrease in body weight gain and colon length as well as an increase of myeloperoxidase (MPO) activity. All COX inhibitors given for 6 days significantly worsened the severity of DSS-induced colonic damage with increased MPO activity. The aggravation was also observed by SC-560 given for the first 3 days or by celecoxib given for the last 3 days. The expression of COX-2 mRNA in the colon was upregulated on day 3 during DSS treatment, with significant increase of prostaglandin E(2) PGE(2) production. The PGE(2) content on day 3 during DSS treatment was inhibited by both indomethacin and SC-560, but not by celecoxib; on day 6 it was suppressed by both indomethacin and celecoxib, but not SC-560. These results suggest that endogenous prostaglandins (PGs) afford protection against colonic ulceration, yet the COX isozyme responsible for the production of PGs differs depending on the stage of ulceration; COX-1 in the early stage and COX-2 in the late stage.

The role of zinc and metallothionein in the dextran sulfate sodium-induced colitis mouse model

Zinc (Zn) and its binding protein metallothionein (MT) have been proposed to suppress the disease activity in ulcerative colitis. To determine the role of Zn and MT in the dextran sulfate sodium (DSS)-induced model of colitis in mice, a DSS dose-response study was conducted in male C57BL/6 wild-type (MT+/+) and MT-null (MT-/-) mice by supplementing 2%, 3%, and 4% DSS in the drinking water for 6 days. In the intervention study, colitis was induced with 2% DSS, Zn (24 mg/ml as ZnO) was gavaged (0.1 ml) daily, concurrent with DSS administration, and the disease activity index (DAI) was scored daily. Histology, MT levels, and myeloperoxidase (MPO) activity were determined. DAI was increased (P<0.05) by 16% and 21% with 3% and 4% concentrations of DSS, respectively, compared to 2%, evident after 5 days of DSS administration. MPO activity was increased in MT+/+ compared to MT-/- mice and those receiving DSS. Zn administration had a 50% (P<0.05) lower DAI compared to DSS alone. Zn partially prevented the distal colon of MT+/+ by 47% from DSS-induced damage compared to MT-/- mice. MT did not prevent DSS-induced colitis and Zn was partially effective in amelioration of DSS-induced colitis.

Analysis of polymorphisms of tumor necrosis factor-alpha and polymorphic xenobiotic metabolizing enzymes in inflammatory bowel disease: study from northern India

BACKGROUND

Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine associated with inflammatory diseases, while GSTM1 and T1 enzymes catalyze detoxification of products of oxidative stress and hence reduce inflammation. Thus, both may play important roles in the pathogenesis of inflammatory bowel disease (IBD). The present study aimed to evaluate the effect of polymorphism of the TNF-alpha promoter at the -308 site, GSTM1 and GSTT1 in patients with IBD and healthy controls from northern India.

METHOD

Genotyping was performed in 114 patients with IBD (22 Crohn's disease [CD] and 92 ulcerative colitis [UC]) in TNF-alpha and 105 (20 CD and 85 UC) in GSTM1 and T1 and 164 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and multiplex PCR methods.

RESULTS

Patients with IBD were comparable to healthy controls in relation to age and gender. Genotypic and allelic frequencies of TNF-alpha were comparable among patients with IBD and healthy controls. GSTM1 null genotype was more frequent in UC than in healthy controls (52/85 vs 49/164; P < 0.001) and GSTT1 null genotype was more frequent both in UC and CD as compared to healthy controls (77/85 and 18/20 vs 26/164, respectively; P < 0.001 for both). Frequency of combined null genotype in GSTM1 and T1 was more frequently associated with IBD than healthy controls (4/20 vs 8/164; P = 0.029, OR = 4.875 and 28/85 vs 8/164; P < 0.001, OR = 9.579, respectively).

CONCLUSIONS

'Null' genotypes of GSTM1 and T1 are associated with IBD and the combination of the two GST genotypes further increases the risk, possibly due to gene-gene interaction. TNF-alpha is unlikely to be an important determinant of susceptibility to IBD in the Indian population.

Bone turnover and nutritional status in Crohn's disease: relationship to circulating mononuclear cell function and response to fish oil and antioxidants

Crohn's disease is associated with osteoporosis, malnutrition and altered function of peripheral blood mononuclear cells (PBMC). The responses of circulating immune cells and extra-intestinal manifestations to increased inflammatory activity and to modulation by dietary supplementation are uncertain. The relationships between disease status, bone turnover and body mass and composition, PBMC function and fatty acid availability have been investigated in patients with Crohn's disease. The availability of n-3 and n-6 PUFA is altered in adult patients and interferon (IFN)-γ production by PBMC is lower. Increased inflammatory activity is associated with increased bone resorption in adult patients and decreased body mass in paediatric patients. In healthy male subjects there is a proportionate relationship between supplementary intake of EPA and DHA (0.3–2.0 g as fish oil/d) in combination with antioxidants (vitamins A, C and E and Se) and incorporation into plasma phospholipids and PBMC, and a non-linear relationship with PBMC synthesis of TNF-α, IL-6 and prostaglandin E2 (decrease) and IFN-γ (increase). In adults with Crohn's disease high-dose fish oil (2.7 g EPA+DHA/d) in combination with antioxidants (vitamins A, C and E and Se) increases the EPA and DHA content of PBMC and decreases the production of IFN-γ by PBMC, but is not associated with effects on bone turnover or nutritional status.

Modulation by heme and zinc protoporphyrin of colonic heme oxygenase-1 and experimental inflammatory bowel disease in the rat

Reactive oxygen species, suggested to be involved in inflammatory bowel disease, may be modulated by endogenous anti-oxidant products of heme oxygenase-1 (HO-1). In the present work, HO-1 expression in trinitrobenzene sulphonic acid (TNBS)-induced colitis in the rat and the effects of HO-1 modulation, particularly by the HO-1 inducer, heme, were further evaluated. Colitis was induced by intracolonic challenge with TNBS and assessed macroscopically and by myeloperoxidase (MPO) assay. Heme oxygenase activity was determined by measurement of bilirubin formation and HO-1 protein expression was determined by Western blotting. TNBS challenge led to an early and substantial induction of HO-1 protein expression and heme oxygenase activity in the colon that peaked after 48-72 h and declined over 10 days. Heme (30 micromol/kg/day, s.c) increased colonic HO-1 protein expression and enzyme activity and decreased colonic damage and myeloperoxidase activity. Short-term administration of cadmium chloride (2 mg/kg, s.c.), another known HO-1 inducer, also reduced the colonic injury and myeloperoxidase levels. In contrast, the HO-1 inhibitor, zinc protoporphyrin (50 micromol/kg/day, s.c) significantly increased the colonic damage and myeloperoxidase activity over 10 days, as did tin protoporphyrin (30 micromol/kg/day, s.c). These results support the proposal that induction of HO-1 provides a protective mechanism in this model under both acute and more-chronic conditions, and that its selective up-regulation could thus be of therapeutic potential in colitis.

Chaga mushroom extract inhibits oxidative DNA damage in lymphocytes of patients with inflammatory bowel disease

Inflammatory Bowel Disease (IBD) is partly caused by oxidative stress from free radicals and reduced antioxidant levels. Using hydrogen peroxide to induce oxidative stress in vitro in peripheral lymphocytes we investigated the induction of DNA damage supplemented with ethanolic extract of Chaga mushroom as a protective antioxidant. Lymphocytes were obtained from 20 IBD patients and 20 healthy volunteers. For treatment, a constant H_{2}O_{2 } dose (50 microg/ml) was used with variable doses of Chaga extract (10-500 microg/ml). DNA damage was evaluated in 50 cells per individual and dose using the Comet assay (making 1000 observations per experimental point ensuring appropriate statistical power). Chaga supplementation resulted in a 54.9% (p < 0.001) reduction of H_{2}O_{2 } induced DNA damage within the patient group and 34.9% (p < 0.001) within the control group. Lymphocytes from Crohn's disease (CD) patients had a greater basic DNA damage than Ulcerative Colitis (UC) patients (p < 0.001). Conclusively, Chaga extract reduces oxidative stress in lymphocytes from IBD patients and also healthy individuals when challenged in vitro. Thus, Chaga extract could be a possible and valuable supplement to inhibit oxidative stress in general.

A traditional Japanese medicine mitigates TNBS-induced colitis in rats

OBJECTIVE

Differences in dietary habits may be one of the reasons that the incidence of inflammatory bowel disease has remained lower in Japan than in Western countries. We investigated whether a traditional Japanese medicine (Strong Wakamto), based on Aspergillus oryzae koji, would exert any effect on experimental colitis in rats.

MATERIAL AND METHODS

Colitis was induced using an enema of trinitrobenzene sulfonic acid (TNBS) and ethanol. Strong Wakamto was administered for 28 days before induction of colitis and for 7 days thereafter, and the effect of this medicine was evaluated.

RESULTS

Treatment with 5% Strong Wakamto improved loss of body-weight, increased colon weight and significantly decreased the histological damage score for colon mucosa. Decreases in faecal Lactobacillus sp., superoxide dismutase activity and zinc concentrations, and the increased IL-1beta expression in colonic tissue after TNBS enema were improved when Strong Wakamto was given. The present in vitro studies indicate that administration of Strong Wakamto prevents lipopolysaccharide-induced TNF-alpha production in human macrophages.

CONCLUSIONS

Oral administration of Strong Wakamto mitigates experimental inflammatory bowel disease induced by TNBS enema in rats. The beneficial effects seem attributable to a combination of balancing microflora, immunomodulatory effects on gut macrophages, and enhancement of anti-superoxide activity in colonic tissues.

Benefits of Zataria multiflora Boiss in Experimental Model of Mouse Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic condition of the intestine with unknown etiology involving multiple immune, genetic and environmental factors. We were interested to examine the effect of total extract from Zataria multiflora Boiss, a folk medicinal plant on prevention and treatment of experimental IBD. Z. multiflora was administered (400, 600, 900 p.p.m.) through drinking water to IBD mice induced by intrarectal administration of acetic acid. Prednisolone was used as the standard drug for comparison. Biochemical, macroscopic and microscopic examinations of colon were performed. Biochemical evaluation of inflamed colon was done using assay of myeloperoxidase (MPO) activity and thiobarbituric acid reactive substances (TBARS) concentration as indicators of free radical activity and cell lipid peroxidation. The activity of MPO and lipid peroxidation products (TBARS) increased in acetic acid-treated groups while recovered by pretreatment of animals with Z. multiflora (400–900 p.p.m.) and prednisolone. Z. multiflora (600 and 900 p.p.m.) and prednisolone-treated groups showed significantly lower score values of macroscopic and microscopic characters when compared with the acetic acid-treated group. The beneficial effect of Z. multiflora (900 p.p.m.) was comparable with that of prednisolone. The antioxidant, antimicrobial and anti-inflammatory potentials of Z. multiflora might be the mechanisms by which this herbal extract protects animals against experimentally induced IBD. Proper clinical investigation should be carried out to confirm the activity in human.

Protection by Ziziphora clinopoides of acetic acid-induced toxic bowel inflammation through reduction of cellular lipid peroxidation and myeloperoxidase activity

Inflammatory bowel disease (IBD) is a chronic condition of the intestine with unknown etiology involving multiple immune, genetic and environmental factors. We were interested in examining the effect of a total extract from Ziziphora clinopoides, an Iranian folk herbal medicine, in the prevention and control of experimental mouse IBD. Z. clinopoides was administered (75, 150, 300 mg/kg) through drinking water to mice, which dispensed a toxic dose of acetic acid intrarectally. Prednisolone was used as the standard drug for comparison. Biochemical, macroscopic and microscopic examinations of the colon were performed. Biochemical evaluation of the inflamed colon was carried out using assays of myeloperoxidase (MPO) activity and thiobarbituric acid reacting substances (TBARS) as indicators of free radical activity and cellular lipid peroxidation. Results indicated that the activity of MPO and lipid peroxidation products (TBARS) increased in acetic acid-treated groups, while recovered by pretreatment of animals with Z. clinopoides (75-300 mg/kg) and prednisolone. All doses of Z. clinopoides and prednisolone-treated groups showed significant lower score values of macroscopic and microscopic characters when compared to the acetic acid-treated group. The beneficial effect of Z. clinopoides (300 mg/kg) was comparable to that of prednisolone. It is concluded that Z. clinopoides inhibits acetic acid toxic reactions in the mouse bowel through inhibition of cellular oxidative stress. Proper clinical investigation should be carried out to confirm the same activity in human.

Colitis-induced oxidative damage of the colon and skeletal muscle is ameliorated by regular exercise in rats: the anxiolytic role of exercise

Epidemiological studies have shown that exercise protects the gastrointestinal tract, reducing the risk of diverticulosis, gastrointestinal haemorrhage and inflammatory bowel disease, while many digestive complaints occurring during exercise are attributed to the adverse effects of exercise on the colon. In order to assess the effects of regular exercise on the pathogenesis of colitis, Sprague-Dawley rats of both sexes were either kept sedentary or given exercise on a running wheel (0.4 km h(-1), 30 min for 3 days week(-1)). At the end of 6 weeks, under anaesthesia, either saline or acetic acid (4%, 1 ml) was given intracolonically. Holeboard tests were performed for the evaluation of anxiety at 24 h before and 48 h after induction of colitis. Increased 'freezing time' in the colitis-induced sedentary group, representing increased anxiety, was reduced in the exercised colitis group (P < 0.05). On the third day following the colonic instillation, the rats were decapitated under brief ether anesthesia and the distal 8 cm of the colons were removed. In the sedentary colitis group, macroscopic and microscopic damage scores, malondialdehyde level and myeloperoxidase activity were increased when compared to the control group (P < 0.01-0.001), while exercise prior to colitis reduced all the measurements with respect to sedentary colitis group (P < 0.05-0.001). The results demonstrate that low-intensity, repetitive exercise protects against oxidative colonic injury, and that this appears to involve the anxiolytic effect of exercise, suggesting that exercise may have a therapeutic value in reducing stress-related exacerbation of colitis.

Redox state and O2*- production in neutrophils of Crohn's disease patients

The aim of this in vitro study was to evaluate the intracellular redox state and respiratory burst (RB) in neutrophils of patients with Crohn's disease (CD). The intracellular redox state and RB in neutrophils was assessed by the superoxide anion (O2*-) production induced in these cells after stimulation by various factors related to the molecular mechanisms that, if altered, may be responsible for an abnormal immune response. This can, in part, cause the onset of inflammation and tissue damage seen in CD. This study demonstrated a decreased glutathione/glutathione disulfide (GSH/GSSG) ratio index of an increased oxidative state in CD patient neutrophils. Moreover, our findings showed a decrease in tumor necrosis factor (TNF-alpha)- or phorbol 12-myristate 13-acetate (PMA)-induced O2*- production in CD patient neutrophils adherent to fibronectin as compared with controls. A decreased adhesion was also demonstrated. For this reason, the involvement of altered mechanisms of protein kinase C (PKC) and beta-integrin activation in CD patient neutrophils is suggested. These data also showed that the harmful effects of TNF-alpha cannot be caused by excessive reactive oxygen species (ROS) production induced by neutrophils. Decreased cell viability after a prolonged time of adhesion (20 hrs) was also measured in CD patient neutrophils. The findings of this study demonstrate, for the first time, that granulocyte-macrophage colony-stimulating factor (GM-CSF), a compound recently used in CD therapy, is able to activate the RB for a prolonged time both in control and CD patient neutrophils. Increased viability of CD patient neutrophils caused by GM-CSF stimulation was also observed. In conclusion, our results indicate that decreased O2*- production and adhesion, caused, in part, by an anomalous response to TNF-alpha, together with low GSH level and low cell viability, may be responsible for the defective neutrophil function found in CD patients. This can contribute to the chronic inflammation and relapses that characterize this pathology. A possible role of GM-CSF in inducing O2*- production and in restoring the defensive role of neutrophils in CD patients is suggested.

Protection against dextran sodium sulfate-induced colitis by dehydroepiandrosterone and 7alpha-hydroxy-dehydroepiandrosterone in the rat

In this study the anti-oxidant effect of DHEA and 7alpha-hydroxy-DHEA against oxidative stress induced by colitis was investigated in vivo in rats. The two steroids were intraperitoneally injected once daily (50 mg/kg body weight) for 7 days before the induction of colitis that was effected by a daily treatment of 5% (w/v) dextran sodium sulfate (DSS) in drinking water for 7 days. This was quantified by the evidence of weight loss, rectal bleeding, increased wall thickness, and colon length. The inflammatory response was assessed by neutrophil infiltration after a histological examination and myeloperoxidase (MPO) activity measurement. Two markers of oxidative damage were measured in colon homogenates after the onset of DSS treatment: protein carbonyls and thiobarbituric acid-reacting substances. The colonic metabolism of corticosterone by 11beta-hydroxysteroid dehydrogenases types 1 and 2 (11beta-HSD) was investigated in control and treated animals. Results indicated that colitis caused a decrease in body weight and colon length. Severe lesions were observed in the colon with a reduced number of goblet cells which contained less mucins. The lesions were associated with increased MPO activity and oxidative damage. Colonic inflammation down and up regulated the 11beta-HSD2 and 11beta-HSD1, respectively. Treatments by DHEA and 7alpha-hydroxy-DHEA attenuated the inflammatory response when MPO activity decreased; but this did not increase the colonic oxidation of corticosterone into 11-dehydrocorticosterone. Both DHEA and 7alpha-hydroxy-DHEA exerted a significant anti-oxidant effect against oxidative stress induced by colitis through reducing the oxidative damage to proteins and lipids. This resulted in a moderate increase in the amount of colonic mucus. Both DHEA and 7alpha-hydroxy-DHEA may prove useful in the prevention or treatment of colitis.

Efficacy and tolerability of oral iron therapy in inflammatory bowel disease: a prospective, comparative trial

BACKGROUND

In patients with inflammatory bowel disease, oral iron is anecdotally reported to be less effective and less well tolerated than in those without inflammatory bowel disease, and to increase disease activity.

AIM

To study prospectively the effects of oral iron in patients with and without inflammatory bowel disease.

METHODS

Patients with ulcerative colitis, Crohn's disease and non-inflammatory bowel disease controls, all with iron deficiency anaemia, were assessed with symptom diaries, a quality of life questionnaire (Inflammatory Bowel Disease Questionnaire; inflammatory bowel disease patients only) and blood tests to measure iron repletion, disease activity and antioxidant capacity before and after starting 4 weeks of oral iron. In patients with ulcerative colitis, sigmoidoscopic scoring and rectal biopsies for reactive oxygen metabolite production were performed before and after iron therapy.

RESULTS

All groups showed increases in haemoglobin and ferritin. Iron intolerance occurred in about a quarter of patients in each group. Two of 33 (6%) of inflammatory bowel disease patients had a relapse during treatment. Symptoms worsened in ulcerative colitis, but not in Crohn's disease or non-inflammatory bowel disease patients; Inflammatory Bowel Disease Questionnaire scores improved in ulcerative colitis. Laboratory markers of disease activity, sigmoidoscopic scores, histological scores, antioxidant capacity levels and reactive oxygen metabolite production did not change.

CONCLUSIONS

Oral iron is equally efficacious and well tolerated in inflammatory bowel disease and non-inflammatory bowel disease patients. A tiny minority of inflammatory bowel disease patients relapse in association with use of oral iron therapy.

High-dose fish oil and antioxidants in Crohn's disease and the response of bone turnover: a randomised controlled trial

Crohn's disease is associated with altered bone turnover that may be influenced by nutritional status, the systemic inflammatory response, cytokine production by circulating (peripheral blood) mononuclear cells (PBMC) and antioxidant micronutrient intake. High-dose fish oil is associated with reductions in disease relapse and inflammatory markers, and modulates PBMC function. The effect of fish oil plus antioxidants on bone turnover and PBMC function (the production of interferon-gamma and prostaglandin E2) in Crohn's disease was investigated in a randomised-controlled trial. Patients with currently or recently raised biochemical markers of inflammation (C-reactive protein > or = 6.9 mg/l or erythrocyte sedimentation rate > or =18 mm/h) received fish oil (providing 2.7 g/d EPA and DHA) and antioxidants (vitamins A, C and E, and Se) (n 31) or placebo (n 30) for 24 weeks. Bone turnover was assessed by measuring the concentrations of urinary deoxypyridinoline (bone resorption) and serum osteocalcin (bone formation). Fish oil plus antioxidants were associated with increases in EPA, DHA Se in plasma (all P < 0.01), and with a reduction in interferon-gamma production by mitogen-stimulated PBMC, which demonstrated a negative correlation with deoxypyridinoline/creatinine:osteocalcin ratio (r - 0.33, P = 0.009). There were no differences between the groups at 24 weeks in the response of deoxypyridinoline or osteocalcin or their ratio, or in nutritional status. Dietary supplementation in Crohn's disease with high intakes of EPA and DHA, as fish oil, plus antioxidants was associated with a modulated production of interferon-gamma by PBMC but not altered indices of bone turnover.

Amelioration of experimental colitis by Astragalus membranaceus through anti-oxidation and inhibition of adhesion molecule synthesis

AIM: To investigate the protective effects of Astragalus membranaceus (Am) against hapten-induced colitis in male Sprague-Dawley rats as well as its underlying mechanism.

METHODS: Experimental colitis was induced in rats by enema administration of 2,4-dinitrobenzene sulfonic acid (DNBS). Rats were either pretreated with Am extract (2 or 4 g/kg, p.o. once daily) starting from 10 d before DNBS enema, or received Am post-treatment (2 or 4 g/kg, p.o. twice daily) on the three consecutive days following DNBS administration. Colonic lesion area and histological damage were determined, while the activities of myeloperoxidase (MPO) and xanthine oxidase, as well as reduced glutathione (GSH) content were measured in the excised colonic tissues. Besides, protein expression of inducible nitrite oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1) and P-selectin was also detected by Western blot analysis.

RESULTS: Our findings had shown that both macroscopic lesion area and histological colonic damage induced by DNBS were significantly reduced by both Am pre- and post-treatments. These were accompanied by attenuation of the elevated colonic MPO activity and downregulation of the iNOS, P-selectin, and ICAM-1 protein expression. Besides, deprivation of colonic GSH level under colitis condition was also preserved.

CONCLUSION: These results demonstrate that Am possesses both preventive and therapeutic potential in experimental colitis. The anti-inflammatory actions involve anti-oxidation along with inhibition of adhesion molecule synthesis in the colonic tissues.

Inhibition of Helicobacter pylori in vitro by various berry extracts, with enhanced susceptibility to clarithromycin

The objective of this study was to evaluate the effects of various berry extracts, with and without clarithromycin on Helicobacter pylori. Resistance to clarithromycin by H. pylori has been reported, leading to interest in alternatives/adjuncts to therapy with clarithromycin. H. pylori American type culture collection (ATCC) strain 49503 was grown, cell suspensions were made in PBS and diluted 10-fold. One hundred microL of the suspension was then incubated for 18 h with extracts of raspberry, strawberry, cranberry, elderberry, blueberry, bilberry, and OptiBerry, a blend of the six berries, at 0.25-1% concentrations. Serially diluted cell suspensions were exposed for 1 h to clarithromycin at 15 microg/ml. Ten microl of bacterial samples from the 10(-7) dilution tube were plated and incubated for 18 h and the number of colonies were counted. Growth of H. pylori was confirmed by the CLO test. All berry extracts significantly (p < 0.05) inhibited H. pylori, compared with controls, and also increased susceptibility of H. pylori to clarithromycin, with OptiBerry demonstrating maximal effects.

Fish oil and antioxidants alter the composition and function of circulating mononuclear cells in Crohn disease

BACKGROUND

Crohn disease (CD) is associated with osteoporosis and other extraintestinal manifestations that might be mediated by cytokines from circulating (peripheral blood) mononuclear cells (PBMCs). Fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduces disease activity in patients with CD with raised laboratory markers of inflammation and in healthy subjects alters PBMC function.

OBJECTIVE

We investigated the effect of fish oil plus antioxidants on cytokine production by PBMCs from patients with CD with raised C-reactive protein concentrations (>/=6.9 mg/L) or erythrocyte sedimentation rates (>/=18 mm/h).

DESIGN

A randomized placebo-controlled trial of fish oil (2.7 g EPA and DHA/d; n = 31) or placebo (olive oil; n = 31) for 24 wk was conducted in patients with CD. The fish-oil group additionally received an antioxidant preparation (vitamins A, C, and E and selenium). Exclusion criteria included corticosteroid use. Fatty acid composition was measured by gas chromatography. Production of tumor necrosis factor alpha, interferon gamma (IFN-gamma), and prostaglandin E(2) (PGE(2)) was measured by enzyme-linked immunosorbent assays after stimulation with mitogen and endotoxin (lipopolysaccharide).

RESULTS

Fish-oil plus antioxidant dietary supplementation was associated with higher EPA and DHA incorporation into PBMCs (P < 0.001) and lower arachidonic acid (P = 0.006) and lower production of IFN-gamma by mitogen-stimulated PBMCs (P = 0.012) and of PGE(2) by lipopolysaccharide-stimulated PBMCs (P = 0.047).

CONCLUSION

Dietary supplementation with fish oil plus antioxidants is associated with modified PBMC composition and lower production of PGE(2) and IFN-gamma by circulating monocytes or macrophages. The response of extraintestinal manifestations of CD should be investigated in a randomized controlled trial.

Protective effect of lafutidine, a novel histamine H2-receptor antagonist, on dextran sulfate sodium-induced colonic inflammation through capsaicin-sensitive afferent neurons in rats

Lafutidine, a histamine H2-receptor antagonist, exhibits gastric mucosal protective action mediated by capsaicin-sensitive afferent neurons, in addition to a potent antisecretory effect. In this study we examined the effect of lafutidine on dextran sulfate Na (DSS)-induced ulcerative colitis in rats, in relation to capsaicin-sensitive afferent neurons. Experimental colitis was induced in rats by daily treatment with 3% DSS in drinking water for 7 days. Lafutidine, capsaicin, and cimetidine were administered per os twice daily for 6 days. The ulceration area, colon length, and myeloperoxidase (MPO) activity were measured on day 7 after the onset of DSS treatment. DSS caused severe mucosal lesions in the colon, accompanied by an increase in MPO activity as well as a decrease in body weight gain and colon length. Daily administration of lafutidine dose-dependently reduced the severity of DSS-induced colitis and significantly mitigated changes in the colon length and MPO activity. The effects of lafutidine were mimicked by daily administration of capsaicin but not cimetidine and were totally abolished by chemical ablation of capsaicin-sensitive afferent neurons. In contrast, desensitization of afferent neurons significantly worsened the colonic inflammation induced by DSS. It was also found that both lafutidine and capsaicin increased the secretion of mucus in the colonic mucosa. These results suggest that lafutidine is effective against the ulcerative colitis induced by DSS through capsaicin-sensitive afferent neurons. This action might be attributable at least partly to the enhancement of colonic mucus secretion.

Expression of heat shock protein 32 (hemoxygenase-1) in the normal and inflamed human stomach and colon: an immunohistochemical study

Heat shock protein 32 (Hsp32, hemoxygenase-1) is induced by reactive oxygen metabolites (ROM) and degrades heme leading to the formation of antioxidant bilirubin. Increased mucosal generation of ROM occurs in gastritis and inflammatory bowel disease. We aimed to assess mucosal expression of Hsp32 in normal stomach and colon and to test the hypothesis that disease-related differential expression occurs in inflamed tissue. Gastric body and antral mucosal biopsies were obtained from 33 patients comprising Helicobacter pylori-negative normal controls (n = 8), H pylori-negative gastritis patients (n = 11), and H pylori-positive gastritis patients (n = 14). Forty-seven archival colonic mucosal biopsies selected comprised normal histology (n = 10), active ulcerative colitis (UC) (n = 9), inactive UC (n = 8), active Crohn's disease (CD) (n = 8), inactive CD (n = 6), and other colitides (n = 6). Hsp32 expression in formalin-fixed sections was assessed by avidin-biotin peroxidase immunohistochemistry using a polyclonal rabbit anti-Hsp32 as the primary antibody. Immunohistochemical staining identified Hsp32 in all groups. Diffuse cytoplasmic staining was seen in gastric and colonic epithelial and lamina proprial inflammatory cells. Staining scores for Hsp32 were higher in antral H pylori-positive (P = 0.002) and H pylori-negative (P = 0.02) gastritis than in controls and in body H pylori-positive gastritis than in the other 2 groups (P < 0.01). Expression of Hsp32 was increased in active UC compared with inactive disease (P = 0.03) and normal controls (P = 0.02). In conclusion, Hsp32 is expressed constitutively in normal gastric and colonic mucosa, and differential expression occurs in these tissues when they are inflamed. Upregulation of Hsp32 may be an adaptive response to protect mucosa from oxidative injury in patients with gastritis and inflammatory bowel disease.

Expression of heat shock protein 32 (hemoxygenase-1) in the normal and inflamed human stomach and colon: an immunohistochemical study

Heat shock protein 32 (Hsp32, hemoxygenase-1) is induced by reactive oxygen metabolites (ROM) and degrades heme leading to the formation of antioxidant bilirubin. Increased mucosal generation of ROM occurs in gastritis and inflammatory bowel disease. We aimed to assess mucosal expression of Hsp32 in normal stomach and colon and to test the hypothesis that disease-related differential expression occurs in inflamed tissue. Gastric body and antral mucosal biopsies were obtained from 33 patients comprising Helicobacter pylori-negative normal controls (n = 8), H pylori-negative gastritis patients (n = 11), and H pylori-positive gastritis patients (n = 14). Forty-seven archival colonic mucosal biopsies selected comprised normal histology (n = 10), active ulcerative colitis (UC) (n = 9), inactive UC (n = 8), active Crohn's disease (CD) (n = 8), inactive CD (n = 6), and other colitides (n = 6). Hsp32 expression in formalin-fixed sections was assessed by avidin-biotin peroxidase immunohistochemistry using a polyclonal rabbit anti-Hsp32 as the primary antibody. Immunohistochemical staining identified Hsp32 in all groups. Diffuse cytoplasmic staining was seen in gastric and colonic epithelial and lamina proprial inflammatory cells. Staining scores for Hsp32 were higher in antral H pylori-positive (P = 0.002) and H pylori-negative (P = 0.02) gastritis than in controls and in body H pylori-positive gastritis than in the other 2 groups (P < 0.01). Expression of Hsp32 was increased in active UC compared with inactive disease (P = 0.03) and normal controls (P = 0.02). In conclusion, Hsp32 is expressed constitutively in normal gastric and colonic mucosa, and differential expression occurs in these tissues when they are inflamed. Upregulation of Hsp32 may be an adaptive response to protect mucosa from oxidative injury in patients with gastritis and inflammatory bowel disease.

Expression of heat shock protein 32 (hemoxygenase-1) in the normal and inflamed human stomach and colon: an immunohistochemical study

Heat shock protein 32 (Hsp32, hemoxygenase-1) is induced by reactive oxygen metabolites (ROM) and degrades heme leading to the formation of antioxidant bilirubin. Increased mucosal generation of ROM occurs in gastritis and inflammatory bowel disease. We aimed to assess mucosal expression of Hsp32 in normal stomach and colon and to test the hypothesis that disease-related differential expression occurs in inflamed tissue. Gastric body and antral mucosal biopsies were obtained from 33 patients comprising Helicobacter pylori-negative normal controls (n = 8), H pylori-negative gastritis patients (n = 11), and H pylori-positive gastritis patients (n = 14). Forty-seven archival colonic mucosal biopsies selected comprised normal histology (n = 10), active ulcerative colitis (UC) (n = 9), inactive UC (n = 8), active Crohn's disease (CD) (n = 8), inactive CD (n = 6), and other colitides (n = 6). Hsp32 expression in formalin-fixed sections was assessed by avidin-biotin peroxidase immunohistochemistry using a polyclonal rabbit anti-Hsp32 as the primary antibody. Immunohistochemical staining identified Hsp32 in all groups. Diffuse cytoplasmic staining was seen in gastric and colonic epithelial and lamina proprial inflammatory cells. Staining scores for Hsp32 were higher in antral H pylori-positive (P = 0.002) and H pylori-negative (P = 0.02) gastritis than in controls and in body H pylori-positive gastritis than in the other 2 groups (P < 0.01). Expression of Hsp32 was increased in active UC compared with inactive disease (P = 0.03) and normal controls (P = 0.02). In conclusion, Hsp32 is expressed constitutively in normal gastric and colonic mucosa, and differential expression occurs in these tissues when they are inflamed. Upregulation of Hsp32 may be an adaptive response to protect mucosa from oxidative injury in patients with gastritis and inflammatory bowel disease.

Expression of heat shock protein 32 (hemoxygenase-1) in the normal and inflamed human stomach and colon: an immunohistochemical study

Heat shock protein 32 (Hsp32, hemoxygenase-1) is induced by reactive oxygen metabolites (ROM) and degrades heme leading to the formation of antioxidant bilirubin. Increased mucosal generation of ROM occurs in gastritis and inflammatory bowel disease. We aimed to assess mucosal expression of Hsp32 in normal stomach and colon and to test the hypothesis that disease-related differential expression occurs in inflamed tissue. Gastric body and antral mucosal biopsies were obtained from 33 patients comprising Helicobacter pylori-negative normal controls (n = 8), H pylori-negative gastritis patients (n = 11), and H pylori-positive gastritis patients (n = 14). Forty-seven archival colonic mucosal biopsies selected comprised normal histology (n = 10), active ulcerative colitis (UC) (n = 9), inactive UC (n = 8), active Crohn's disease (CD) (n = 8), inactive CD (n = 6), and other colitides (n = 6). Hsp32 expression in formalin-fixed sections was assessed by avidin-biotin peroxidase immunohistochemistry using a polyclonal rabbit anti-Hsp32 as the primary antibody. Immunohistochemical staining identified Hsp32 in all groups. Diffuse cytoplasmic staining was seen in gastric and colonic epithelial and lamina proprial inflammatory cells. Staining scores for Hsp32 were higher in antral H pylori-positive (P = 0.002) and H pylori-negative (P = 0.02) gastritis than in controls and in body H pylori-positive gastritis than in the other 2 groups (P < 0.01). Expression of Hsp32 was increased in active UC compared with inactive disease (P = 0.03) and normal controls (P = 0.02). In conclusion, Hsp32 is expressed constitutively in normal gastric and colonic mucosa, and differential expression occurs in these tissues when they are inflamed. Upregulation of Hsp32 may be an adaptive response to protect mucosa from oxidative injury in patients with gastritis and inflammatory bowel disease.

Anti-inflammatory effects of aloe vera gel in human colorectal mucosa in vitro

BACKGROUND

Oral aloe vera gel is widely used by patients with inflammatory bowel disease and is under therapeutic evaluation for this condition.

AIM

To assess the effects of aloe vera in vitro on the production of reactive oxygen metabolites, eicosanoids and interleukin-8, all of which may be pathogenic in inflammatory bowel disease.

METHODS

The anti-oxidant activity of aloe vera was assessed in two cell-free, radical-generating systems and by the chemiluminescence of incubated colorectal mucosal biopsies. Eicosanoid production by biopsies and interleukin-8 release by CaCo2 epithelial cells in the presence of aloe vera were measured by enzyme-linked immunosorbent assay.

RESULTS

Aloe vera gel had a dose-dependent inhibitory effect on reactive oxygen metabolite production; 50% inhibition occurred at 1 in 1000 dilution in the phycoerythrin assay and at 1 in 10-50 dilution with biopsies. Aloe vera inhibited the production of prostaglandin E2 by 30% at 1 in 50 dilution (P = 0.03), but had no effect on thromboxane B2 production. The release of interleukin-8 by CaCo2 cells fell by 20% (P < 0.05) with aloe vera diluted at 1 in 100, but not at 1 in 10 or 1 in 1000 dilutions.

CONCLUSION

The anti-inflammatory actions of aloe vera gel in vitro provide support for the proposal that it may have a therapeutic effect in inflammatory bowel disease.

The bactericidal effects of Lactobacillus acidophilus, garcinol and Protykin compared to clarithromycin, on Helicobacter pylori

Chronic infection with Helicobacter pylori causes peptic ulcers, gastric cancer and lymphoma. We evaluated the inhibitory effects of the probiotic Lactobacillus acidophilus DDS-1J, the antibiotic clarithromycin and the natural antioxidants garcinol and Protykin (containing 50% trans-resveratrol) on Helicobacter pylori strain ATCC 49503. The findings of this study indicate that Lactobacillus acidophilus DDS-1J exerts a growth inhibitory effect on H. pylori at a ratio of 1:1 or higher in vitro. In the case of clarithromycin, garcinol and resveratrol, the bactericidal effect is time and concentration dependent. Clarithromycin completely inhibited growth at > or = 62.5 microg/ml at 6 h and at > or = 31.5 microg/ml at 12 h. For garcinol the highest concentration needed for complete inhibition was 31.5 microg/ml at 6 h and 3.9 microg/ml after 12 h incubation. For resveratrol, significant inhibition was noted at 1000 microg/ml at 12 h only. The bactericidal effect of garcinol was reduced by the addition of resveratrol at all concentrations < or = 125 microg/ml at 6 and 12 h. We conclude from this study that Lactobacillus acidophilus DDS-1J inhibits H. pylori at 1:1 and higher ratios. Also, between the two antioxidants, garcinol is much more potent than resveratrol as a bactericidal agent against H. pylori, and that resveratrol may antagonize this effect. Finally, our study showed equivalent or better bactericidal activity of garcinol compared to clarithromycin against H. pylori at 6 and 12 h incubation, indicating a potential role for this antioxidant in treatment for H. pylori infection.

Helicobacter pylori-induced oxidative stress and DNA damage in a primary culture of human gastric mucosal cells

Helicobacter pylori has been identified in the pathogenesis of chronic active gastritis and peptic ulcer disease and is epidemiologically linked to gastric cancer and lymphoma. Our previous studies have demonstrated enhanced production of reactive oxygen species (ROS) in cultured gastric adenocarcinoma cells (ATCC CRL/1739) in association with H. pylori. Recently, we have isolated and cultured normal human gastric mucosal cells (GMC) from H. pylori-negative endoscopic biopsies. The integrity of these mucosal cells was determined by periodic acid-Schiff staining. We assessed the effects of various H. pylori strains including 60190 (a 87-kDa cytotoxin producing strain), ATCC 43504, and 60190-v1 (in which the cytotoxin gene has been disrupted) on the primary culture of human gastric mucosal cells. The induction of ROS and DNA fragmentation in the mucosal cells in association with these H. pylori strains were assessed by cytochrome c reduction (an index of superoxide anion production), hydroxyl radical production, and DNA fragmentation. Following incubation of the mucosal cells with 1:0.5 and 1:1 ratios of H. pylori strain 60190, approximately 6.2- and 9.9-fold increases were observed in cytochrome c reduction, respectively, as compared to mucosal cells in the absence of H. pylori, demonstrating the production of superoxide anion. The detection of hydroxyl radicals based on the formation of 2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid was determined by using a high-performance liquid chromatograph equipped with an electrochemical detector. Approximately 3.5- and 7.7-fold increases in hydroxyl radical production were observed following incubation of the mucosal cells with 1:0.5 and 1:1 ratios of H. pylori, respectively. Approximately 3.6- and 4.5-fold increases in DNA fragmentation were observed in gastric mucosal cells following incubation with 1:0.5 and 1:1 ratios of H. pylori, respectively. The effects of culture supernatant preparations from H. pylori strains 60190 and 60190-v1 on the enhanced production of ROS and increased DNA fragmentation in mucosal cells were also investigated. Culture supernatant preparations, the prime source of the 87-kDa cytotoxin, from both H. pylori strains 60190 and 60190-v1 were extracted under identical conditions to determine the role of 87-kDa cytotoxin on the enhanced production of ROS and DNA fragmentation. The cytotoxin rich-H. pylori strain 60190 induced greater production of ROS and DNA fragmentation in mucosal cells as compared to the supernatant preparation from H. pylori strain 60190-v1, in which the cytotoxin gene has been disrupted. This study demonstrates that H. pylori induces enhanced production of ROS and DNA damage in association with human gastric mucosal cells and that the 87-kDa cytotoxin protein plays a prime role in the induction of oxidative stress and DNA damage.

Antioxidant effects of herbal therapies used by patients with inflammatory bowel disease: an in vitro study

BACKGROUND

Herbal remedies used by patients for treatment of inflammatory bowel disease include slippery elm, fenugreek, devil's claw, Mexican yam, tormentil and wei tong ning, a traditional Chinese medicine. Reactive oxygen metabolites produced by inflamed colonic mucosa may be pathogenic. Aminosalicylates (5-ASA) are antioxidant and other such agents could be therapeutic.

AIMS

To assess the antioxidant effects of herbal remedies in cell-free oxidant-generating systems and inflamed human colorectal biopsies.

METHODS

Luminol-enhanced chemiluminescence in a xanthine/xanthine oxidase cell-free system was used to detect superoxide scavenging by herbs and 5-ASA, and fluorimetry to define peroxyl radical scavenging using a phycoerythrin degradation assay. Chemiluminescence was used to detect herbal effects on generation of oxygen radicals by mucosal biopsies from patients with active ulcerative colitis.

RESULTS

Like 5-ASA, all herbs, except fenugreek, scavenged superoxide dose-dependently. All materials tested scavenged peroxyl dose-dependently. Oxygen radical release from biopsies was reduced after incubation in all herbs except Mexican yam, and by 5-ASA.

CONCLUSIONS

All six herbal remedies have antioxidant effects. Fenugreek is not a superoxide scavenger, while Mexican yam did not inhibit radical generation by inflamed biopsies. Slippery elm, fenugreek, devil's claw, tormentil and wei tong ning merit formal evaluation as novel therapies in inflammatory bowel disease.

Antioxidant status and lipid peroxidation in colorectal cancer

Colon carcinogenesis is a multistep process where oxygen radicals were found to enhance carcinogenesis at all stages: initiation, promotion, and progression. Since insufficient capacity of protective antioxidant system can result in cancer, the aim of this study was to examine the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and the levels of reduced glutathione, vitamin C, and vitamin E. The lipid peroxidation products were also determined by measuring malondialdehyde and 4-hydroxynonenal levels in colorectal cancer tissue collected from 55 patients. In these cases the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase was significantly increased while the activity of catalase was significantly decreased in cancer tissue. However, the level of nonenzymatic antioxidant parameters (glutathione, vitamin C, and vitamin E) was significantly decreased in cancer tissue. Further lipid peroxidation was enhanced during cancer development, manifested by a significant increase in malondialdehyde and 4-hydroxynonenal levels. The obtained results indicate significant changes in antioxidant capacity of colorectal cancer tissues, which lead to enhanced action of oxygen radicals, resulting in lipid peroxidation.

Recent advances in inflammatory bowel disease

The last decade has seen tremendous advances in our knowledge, which has led to genuine improvements in our understanding of the pathogenesis and management of inflammatory bowel disease (IBD). The combined power of cellular and molecular biology has begun to unveil the enigmas of IBD, and, consequently, substantial gains have been made in the treatment of IBD. Refinements in drug formulation have provided the ability to target distinct sites of delivery, while enhancing the safety and efficacy of older agents. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This article addresses our current understanding of the pathogenesis of IBD, including the latest developments in animal models and covers agents currently used in the treatment of IBD as well as emerging therapies.

Effects of iron and iron chelation in vitro on mucosal oxidant activity in ulcerative colitis

BACKGROUND

Reactive oxygen species may be pathogenic in ulcerative colitis. Oral iron supplements anecdotally exacerbate inflammatory bowel disease and iron levels are elevated in the inflamed mucosa. Mucosal iron may enhance hydroxyl ion production via Fenton chemistry. Conversely, the iron chelator, desferrioxamine, is reportedly beneficial in Crohn's disease.

AIMS

To assess the in vitro effects of exogenous iron and of iron chelators on the production of reactive oxygen species by colonic biopsies from normal control subjects and patients with ulcerative colitis.

METHODS

Luminol-amplified chemiluminescence was used to measure mucosal reactive oxygen species production both before and after addition in vitro of ferric citrate (100 microM), desferrioxamine (1 mM) and 1,10-phenanthroline (1 mM).

RESULTS

Ferric citrate had no effect on the chemiluminescence produced by human colonic mucosa. However, desferrioxamine and phenanthroline reduced chemiluminescence by 47% (n=7, P=0.018) and by 26% (n=10, P=0.005), respectively, in inactive ulcerative colitis, and by 44% (n=9, P=0. 008) and 42% (n=11, P=0.006) in active disease.

CONCLUSION

The lack of effect of ferric citrate suggests that sufficient free iron is already present in inflamed biopsies to drive the Fenton reaction maximally. The effects of desferrioxamine and 1,10-phenanthroline on the chemiluminescence of biopsies from patients with ulcerative colitis suggest that a clinical trial of topical iron chelation in active disease is indicated.

Allopurinol in addition to 5-aminosalicylic acid based drugs for the maintenance treatment of ulcerative colitis

BACKGROUND

To investigate the value of combined treatment with allopurinol and 5-aminosalicylic (5-ASA) based drugs as maintenance treatment for ulcerative colitis (UC).

METHODS

199 patients with UC in remission but with active disease during the preceding 3 years were included. Allopurinol 100 mg twice daily or placebo was added to the 5-ASA based maintenance treatment. Clinical and endoscopic follow up was performed after 1, 6 and 12 months.

RESULTS

Intention-to-treat analysis after 6 and 12 months showed similar results in both groups. A log-rank test showed that 77% in the allopurinol compared to 59% in the placebo group were still in remission after 6 months (P=0.0083) and 62% and 53% after 12 months, respectively (P=0.0936). This was mainly due to a higher than expected number of relapses during the first 3 months in the placebo group. After the first 3 months, the rate of relapse in each group was similar.

CONCLUSIONS

It appears possible that allopurinol in combination with 5-ASA is better than 5-ASA alone for a 6-month, but not a 12-month period. This has to be verified in further dose-ranging studies.

Replenishment of glutathione levels improves mucosal function in experimental acute colitis

Because reactive oxygen species (ROS) have been implicated as mediators of inflammatory bowel disease (IBD), the purpose of the present work was to determine the functional role of mucosal GSH in the trinitrobenzenesulfonic acid in 50% ethanol (TNBS+ethanol)-induced colitis in rats. Mucosal samples were taken to evaluate the temporal relationship between the extent of injury, the levels of glutathione (GSH) during acute colitis induced by TNBS+ethanol, and the effect of N-acetylcysteine (NAC) administration. In vitro assays revealed the interaction of TNBS with GSH leading to the almost instantaneous disappearance of GSH, while the reductive metabolism of TNBS by GSSG reductase generated ROS. Mucosal samples from TNBS+ethanol-treated rats indicated a direct correlation between GSH depletion and injury detected as soon as 30 minutes after TNBS+ethanol administration that persisted 24 hours post treatment. Although, short term depletion of mucosal GSH per se by diethylmaleate did not result in mucosal injury, the oral administration of NAC (40 mM) 4 hours after TNBS+ethanol treatment increased GSH stores (2-fold), decreasing the extent of mucosal injury (60-70%) examined at 24 hours post treatment. However, an equimolar dose of dithiothreitol failed to increase GSH levels and protect mucosa from TNBS+ethanol-induced injury. Interestingly, GSH levels in TNBS+ethanol-treated rats recovered by 1-2 weeks, an effect that was accounted for by an increase of gamma-glutamylcysteine synthetase (gamma-GCS) activity due to an induction of gamma-GCS-heavy subunit chain mRNA. Thus, TNBS promotes two independent mechanisms of injury, GSH depletion and ROS generation, both being required for the manifestation of mucosal injury as GSH limitation renders intestine susceptible to the TNBS-induced ROS overgeneration. Accordingly, in vivo administration of NAC attenuates the acute colitis through increased mucosal GSH levels, suggesting that GSH precursors may be of relevance in the acute relapse of IBD.

Nutritional supplementation with N-3 fatty acids and antioxidants in patients with Crohn's disease in remission: effects on antioxidant status and fatty acid profile

In patients with Crohn's disease (CD), malnutrition is frequently observed and is generally accepted to be an important issue. The aim of this study was to investigate the effects of 3 months of supplementation with a liquid formula containing either antioxidants (AO) or n-3 fatty acids plus AO on the antioxidant status and fatty acid profile of plasma phospholipids and adipose tissue, respectively, in patients with long-standing CD currently in remission. In a randomized, double-blind placebo-controlled study, CD patients received either placebo, AO, or n-3 fatty acids plus AO for 3 months in addition to their regular diet. In all, 25/37 CD patients completed the study. AO status was assessed by blood biochemical parameters. A statistical per-protocol analysis was performed. Serum concentrations of selenium, vitamin C, and vitamin E, the activity of superoxide dismutase and total antioxidant status were significantly (p < 0.05) increased after AO supplementation. Furthermore, compared with controls, serum concentrations of beta-carotene, selenium, and vitamin C and the activity of glutathione peroxidase (GPx) were significantly (p < 0.05) lower before supplementation; however, after AO supplementation these levels were not significantly different from controls (except for GPx). N-3 fatty acids plus AO supplementation significantly (p < 0.05) decreased the proportion of arachidonic acid, and increased the proportion of eicosapentanoic acid and docosahexanoic acid in both plasma phospholipids and adipose tissue. Supplementation with antioxidants improved antioxidant status in patients with CD in remission. In addition, supplementation with n-3 fatty acids plus antioxidants significantly changed the eicosanoid precursor profile, which may lead to the production of eicosanoids with attenuated proinflammatory activity. This study indicates that an immunomodulating formula containing n-3 fatty acids and/or AO may have the potential to play a role in the treatment of CD.

Effect of D-002 on acetic acid-induced colitis in rats at single and repeated doses

D-002 is a natural mixture of higher aliphatic primary alcohols purified from beeswax, with mild anti-inflammatory and effective antiulcer effects experimentally proved. Furthermore, it reduces leukotriene (LTB(4)) in the exudate of carrageenan-induced pleurisy and has a protective effect on the pre-ulcerative phase of carrageenan-induced colonic ulceration in the guinea pig. This study was conducted to determine the effect of D-002 on acetic acid-induced colitis in rats at single and repeated doses. In a first series, D-002 was orally administered at 25 and 50 mg kg(-1), 24 h before the induction of colitis, meanwhile, in a second series, it was administered 24 h after the induction of colitis. Two other series (III and IV) examined the protective and therapeutic effect of D-002 administered for 7 days at the same doses, before or after colitis induction. Significant reductions in wet weight, macroscopic injury, polymorphonuclear infiltration and wall thickness were observed in colonic mucosa of D-002-treated animals compared with controls in both protective and therapeutic alternatives. It is concluded that D-002 was effective to protect or prevent the damage associated to acetic acid-induced colitis.

Antioxidant and immune status in active Crohn's disease. A possible relationship

BACKGROUND AND AIMS

As reactive oxygen has been demonstrated to participate in immune genes transcription, the aim of this study was to examine the relationship between systemic concentrations of several antioxidants and markers of inflammatory and immune activation in patients with Crohn's disease (CD).

METHODS

In 26 CD patients and 15 controls we compared plasma selenium and zinc concentrations, erythrocyte glutathione peroxidase (GSHPx) and superoxide dismutase activities, as well as erythrocyte sedimentation rate (ESR), C-reactive protein, tumor necrosis factor-alpha, interleukin-6, blood neopterin and soluble receptors of interleukin-2 (sIL-2R), and examined the link between these parameters.

RESULTS

Selenium concentration and GSHPx activity were decreased in CD patients (54.5 +/- 3.2 vs 79 &plusmn 2.2 microg/l, P<< 0.05; 28 +/- 1.6 vs 38 +/- 2.6 IU/g Hb, P<< 0.05) and positively correlated to each other's (r= 0.59, P<< 0.01). TNF-alpha was significantly increased in patients (18 +/- 2.6 vs 5 +/- 0.6 pg/ml;P<< 0.001), negatively correlated to GSHPx activity (r= -0.56, P<< 0.05) and selenium concentration (r= -0.72, P<< 0.001), and positively to neopterin and sIL-2R concentrations. Selenium showed negative correlation with sIL-2R (r= -0.83, P<< 0.0001) and ESR.

CONCLUSIONS

In CD patients low selenium concentration may participate in reduced GSHPx activity facilitating inflammatory and immune activation. In these patients, selenium monitoring and, if needed, supplementation may be of therapeutical interest.

Properties of fucoidan from Cladosiphon okamuranus tokida in gastric mucosal protection

To elucidate the anti-ulcer potential of Cladosiphon fucoidan, anti-peptic activity, bFGF stabilizing activity and inflammatory properties of this and related substances were investigated. Anti-peptic activity was observed with this and other sulfated polysaccharides such as dextran sulfate, carrageenan, and Fucus fucoidan. However, non-sulfated polysaccharides such as mannan and dextran did not exert the anti-peptic activity. The loss of bFGF bioactivity was prevented by all sulfated polysaccharides tested except chondroitin sulfate, at pH 7.4 and at pH 4.0. At pH 2.0, only heparin protected the bFGF activity. The generation of superoxide by macrophages and PMNs was stimulated by dextran sulfate, carrageenan, and Fucus fucoidan, whereas Cladosiphon fucoidan, heparin and chondroitin did not. Dextran sulfate, carrageenan, and Fucus fucoidan also stimulated the secretion of TNFalpha from macrophages, while Cladosiphon fucoidan did not. Thus, Cladosiphon fucoidan is a sulfated polysaccharide without inflammatory action. These results suggest that Cladosiphon fucoidan is a safe substance with potential for gastric protection.

The relation between antioxidant status and alterations in fatty acid profile in patients with Crohn disease and controls

BACKGROUND

A diminished antioxidant defence and alterations in the fatty acid profile may play a role in the pathophysiology of inflammation in Crohn disease (CD).

METHODS

Antioxidant status (serum antioxidant vitamins and minerals, glutathione peroxidase, and superoxide dismutase activity), disease activity, dietary intake, and the fatty acid profile in plasma and erythrocyte phospholipids were studied in patients with active CD (n = 12), inactive CD (n = 50), and controls (n = 70). Eight patients with active CD were re-evaluated during the subsequent phase of clinical remission. The relation between the variables was assessed by multiple linear regression.

RESULTS

We observed a significantly diminished antioxidant status in patients with active CD compared with inactive CD and controls. Furthermore, the antioxidant defence was depleted in patients with inactive CD compared with controls. An aberrant fatty acid profile in plasma phospholipids was found in active and inactive CD compared with controls. Multivariate analysis showed that the plasma phospholipid fatty acid indices were significantly associated with several antioxidants (beta-carotene, vitamin E, and glutathione peroxidase) in CD patients but not in controls.

CONCLUSION

The fatty acid profile in CD patients is significantly associated with disease activity and serum antioxidant concentrations. This observation, along with the diminished antioxidant defence in patients with active and inactive CD, indicates that antioxidants should be considered in the therapy of inflammation in CD.

Deferiprone, an oral iron chelator, ameliorates experimental colitis and gastric ulceration in rats

Iron is pivotal is producing tissue-damaging reactive oxygen metabolites. Our aim is to determine the antiinflammatory activity of deferiprone, an oral iron chelator, in experimental colitis and gastritis. Colitis was induced by intraceccal administration of 2 ml 5% acetic acid or by intracolonic administration of 0.1 ml 3% iodoacetamide, with or without cotreatment with deferiprone. Gastritis was induced by intragastric administration of ethanol or hydrochloric acid (HCl) and by subcutaneous injection of indomethacin, with and without deferiprone. Rats were killed 24 hours after acetic acid and iodoacetamide, 30 minutes after ethanol, one hour after HCl, and three hours after indomethacin administration. The colon or stomach was isolated, macroscopic damage was measured, and mucosal samples were obtained for determination of eicosanoid generation, myeloperoxidase (MPO), and nitric oxide synthase (NOS) activities. Deferiprone decreased iodoacetamide and acetic acid-induced macroscopic colonic damage by 67% and 69%, respectively, and macroscopic gastric damage by 91%, 68%, and 46% induced by ethanol, HCl, and indomethacin, respectively. The effect of deferiprone was accompanied by significant decrease in colonic and gastric, MPO and NOS activities, and colonic prostaglandin E2 (PGE2) generation, in acetic acid, ethanol, and indomethacin models, whereas in the iodoacetamide and HCl models attenuation of the decrease in PGE2 generation was seen. Deferiprone is protective in experimental colitis and gastritis, probably due to decreased production of iron-dependent oxygen-free radicals. Oral iron chelators may constitute a novel approach to ameliorate gastrointestinal inflammatory disorders.

L-glutamine enemas attenuate mucosal injury in experimental colitis

PURPOSE

The aim of this study was to investigate the role of 1-glutamine, short chain fatty acid, prednisolone, and mesalazine (5-aminosalicylic acid) enemas on mucosal damage and inflammation in experimental colitis.

METHODS

Colitis was induced in rats with trinitrobenzene sulfonic acid in ethanol. Saline (n = 14), prednisolone (n = 13), 5-aminosalicylic acid (n = 14), 1-glutamine (n = 14), and short chain fatty acid (n = 13) enemas were applied twice daily to the rats for seven days after the induction of colitis. The sham group (n = 9) received only saline enemas. Rats were killed at the seventh day and their colonic macroscopic inflammatory scores were determined. Colonic mucosal gamma glutamyl transpeptidase activity and colonic mucosal malondialdehyde levels were measured. The same measurements but no enemas were done in the control group (n = 7).

RESULTS

There were significant differences in macroscopic inflammatory scores between sham and colitis groups (P < 0.001). The macroscopic inflammatory scores of the colitis group were higher than the short chain fatty acid and glutamine groups (P < 0.05). Whereas the mucosal gamma glutamyl transpeptidase activity was diminished in prednisolone, 5-aminosalicylic acid, and short chain fatty acid groups when compared with the control group; in the colitis, sham, and glutamine groups the activity of this enzyme did not change. The mucosal malondialdehyde levels were significantly lower in the prednisolone and glutamine groups than in the colitis group.

CONCLUSION

Only one of four agents tested, namely, 1-glutamine enemas, could decrease the severity of colitis both morphologically and biochemically. Moreover, L-glutamine prevented the colitis-induced oxidant injury in the colonic mucosa. On the other hand, prednisolone and short chain fatty acids seemed to improve only the physiologic changes of colitis.

Increased interleukin-8 (IL-8) in rectal dialysate from patients with ulcerative colitis: evidence for a biological role for IL-8 in inflammation of the colon

OBJECTIVE

Infiltration of neutrophils and their release of toxic reactive oxygen species (ROS) in the colonic mucosa are associated with tissue damage in ulcerative colitis (UC). This neutrophil migration may be induced by chemoattractants, such as cytokines, in the colonic milieu. One such chemoattractant is interleukin-8 (IL-8), a neutrophil chemokine that is present at high concentrations in inflamed mucosa. However, the functional significance of IL-8 in neutrophil attraction and activation in UC has not been established. We hypothesized that IL-8 in the colonic lumen of patients with UC primes neutrophils, leading to their attraction and activation.

METHODS

The colonic milieu was sampled by rectal dialysis. Using a semi-permeable membrane with a molecular weight cut-off of 12 kDa, dialysis solution was placed in the rectum and allowed to equilibrate over a 4-h period with the colonic milieu of controls or of patients with UC. IL-8 concentrations were measured by ELISA. Two functions of healthy neutrophils (PMN) were measured: expression of CD11-b surface adhesion molecules (by flow cytometry), and production of ROS (by both chemiluminescence and cytochrome C reduction assays). Neutrophil functions after exposure to rectal dialysates or n-formyl-methionyl-leucyl-phenylalanine (fMLP) were assessed before and after adding anti-IL-8 antibody or the fMLP blocker BMLP.

RESULTS

IL-8 concentrations in dialysates from patients with active UC were significantly higher than in controls and correlated with disease activity. UC dialysates significantly increased ROS production and CD11-b expression by neutrophils and anti-IL-8 antibody partially (50%) inhibited these stimulatory effects of UC dialysates. Preincubation of neutrophils with UC dialysates significantly potentiated the fMLP-induced rise in ROS and anti-IL-8 antibody completely abolished this priming effect.

CONCLUSIONS

The colonic milieu, sampled by rectal dialysis, from patients with active UC can both activate and prime neutrophils in vitro. High concentrations of IL-8 in the colonic lumen of UC patients are partially responsible for the activating effects of rectal dialysates, and account for all of its priming effects. These findings provide direct evidence for a role for IL-8 in inflammatory bowel disease.

Immunohistochemical evaluation of Bcl-2 gene family expression in liver of hepatitis C and cirrhotic patients: a novel mechanism to explain the high incidence of hepatocarcinoma in cirrhotics

OBJECTIVE

The purpose of this study was to determine whether there is an increase in expression of bcl-2 and related bcl-2 gene family members bcl-X and bax in liver biopsy samples obtained from patients with either hepatitis C infection or cirrhosis. Bcl-2, bcl-X, and bax, as well as other bcl-2-related proteins, function coordinately through homo- and heterodimerization to regulate apoptosis. Bcl-2, which is characterized as an antiapoptotic, also functions as an antioxidant. We hypothesized that a mechanism that could account for increased hepatocellular carcinoma in patients with hepatitis C and cirrhosis is selection of bcl-2 expressing cells. This selection would be due to the capacity of individual cells to resist the toxic effects of inflammatory byproducts, specifically reactive oxygen species.

METHODS

Sections cut from archived liver biopsy samples embedded in paraffin were probed with antibody specific for bcl-2, bcl-X, or bax. Liver samples were from normal (N = 5), hepatitis C patients (N = 19), and cirrhotics (N = 10). Percent positive staining and intensity of staining were judged independently for hepatocytes, bile ducts, mononuclear cells, and Kupffer cells.

RESULTS

Bcl-2 expression was evident in bile ducts and mononuclear cells of hepatitis C patients, but was not commonly present in hepatocytes (two of 10). In the cirrhotic liver, bcl-2 expression was also detected in bile ducts and mononuclear cells, but in contrast to hepatitis patients was also expressed in hepatocytes (nine of 10). A similar pattern of expression was evident for bcl-X, but in general the level of expression was limited relative to that of bcl-2. Bax expression was infrequently present in sections from any of the three patient groups.

CONCLUSIONS

The data indicate that bcl-2 expression is elevated in the liver of cirrhotics, but is not evident in the liver of hepatitis C patients. This increase in expression of bcl-2 in cirrhotic patients may correlate with development of hepatocellular carcinoma given the anti-apoptotic/oncogenic potential of bcl-2.