Novel Antioxidants Zolimid andAEOL11201 Ameliorate Colitis in Rats
S. CHOUDHARY,* A. KESHAVARZIAN, MD,*†‡§ S. YONG,¶ M. WADE,** S. BOCCKINO,††B.J. DAY,‡‡ and A. BANAN*
The mechanism of tissue damage in ulcerative colitis (UC) is unknown. However, recentevidence suggests that reactive oxygen species (ROS) are critical mediators of inflammation,and tissue damage in UC and antioxidants could be beneficial in the treatment of UC. Ouraim was to evaluate the effects of two new antioxidants, Zolimid and AEOL11201 onexperimental colitis. Antioxidants or vehicle were given to rats for five days after induction ofcolitis by intrarectal administration of 4% acetic acid. Severity of colitis was assessed on day5. Zolimid and AEOL11201 significantly improved acetic acid-induced colitis. Both Zolimidand AEOL11201 significantly decreased the severity of diarrhea, and severity of macroscopicand histological changes in the colon. Both agents also significantly decreased colonic MPOlevels. In conclusion, Zolimid and AEOL11201 are effective antiinflammatory agents in ananimal model of colitis. Further studies are needed to evaluate their beneficial therapeuticeffects in patients with UC.
The etiology and the mechanisms of tissue damage inulcerative colitis (UC) and Crohn’s disease (CD), twocommon forms of chronic inflammatory bowel dis-ease (IBD) are poorly understood (1). The acutephase of UC and CD is characterized by colonicmucosal injury with ulceration and the presence oflarge numbers of neutrophils (PMN) in the areas oftissue damage (2–6). It has been suggested that neu-
trophils exert their injurious effects on intestinal mu-cosa through their secretory products such as reactiveoxygen species (ROS) and proteases. Indeed, highlevels of ROS have been reported in both patientswith UC and in animal model of colitis (7–13).
It is therefore not surprising that effective antiin-flammatory agents for treatment of UC, such as sul-fasalazine and mesalamine have antioxidant proper-ties (14, 15). Furthermore, we have shown that morespecific antioxidants such as superoxide dismutase(SOD) and catalase significantly improve tissue dam-age in animal models of colitis (16). Unfortunatelythese specific antioxidants are either not suitable forclinical use or their safety has not been evaluated. Forexample, SOD has a very short half-life, making itunsuitable for therapy in humans. The modified SOD,PEG-SOD, has an acceptable half-life but is a largemolecule that poorly penetrates into cells. Potentsmall molecule antioxidants may overcome the previ-ously observed problems with large molecule antioxi-dants. These agents may therefore prove useful in thetreatment of patients with IBD, especially those who
Manuscript received May 31, 2000; revised manuscript receivedMarch 19, 2001; accepted April 30, 2001.
From the Departments of *Medicine (Division of DigestiveDiseases), †Pharmacology, and ‡Molecular Biology and Physiol-ogy, §Rush Presbyterian St Lukes Medical Center, Chicago, Illi-nois; Research Service Hines Veterans Affair Hospital, Hines,Illinois, ¶Department of Pathology, Loyola University School ofMedicine, Maywood, Illinois; **Cytos Pharmaceuticals, Durham,North Carolina; ††Aeolus Pharmaceuticals, Inc., Research Trian-gle Park, North Carolina; and ‡‡Department of Medicine, NationalJewish Medical and Research Center, Denver, Colorado.
This study was supported by grants from Cytos Pharmaceuticals,Research Triangle Park, North Carolina; Aeolus Pharmaceuticals,Inc., Research Triangle Park, North Carolina; from Rush Univer-sity Medical School.
Address for reprint requests: Dr. Ali Keshavarzian, Division ofDigestive Disease, Rush Presbyterian St-Lukes Med Center, 1725W Harrison Suite 204, Chicago, Illinois 60612.
do not respond to available agents or cannot toleratethem, due to side effects or allergic reactions.
Zolimid and AEOL11201 have the potential to besuch promising agents. Zolimid is an amino acidanalog that is a water-soluble compound readily ab-sorbed from the intestine. Zolimid has been widelyused in humans with no side effects, and it is known tobe a potent antioxidant both in cell-free and cellularmedia. AEOL11201 is a new manganese porphyrinthat is part of a potent class of catalytic antioxidants.
The aim of the current study was to determine ifZolimid and AEOL11201 were effective in the treat-ment of animal model of ulcerative colitis, an oxidant-mediated disorder. Several animal models of colitishave been described (7, 8, 17, 18), one such model isacetic acid-induced colitis (19, 20). Acetic acid colitisis a reproducible and simple model, sharing manycharacteristics with human colitis. We utilized thismodel of colitis to evaluate the effect of Zolimid andAEOL11201 on tissue damage and colonic inflamma-tion.
MATERIALS AND METHODS
Induction of Colitis in Rats by Acetic Acid. Colitis wasinduced in male Sprague-Dawley rats (200–250 g; Harlan,Indianapolis, Indiana) by intrarectal (IR) administration of1.5 ml of 4% acetic acid. Animals were allowed to eat anddrink ad libitum throughout all experiments. All surgicalprocedures were conducted using sterile techniques. Ani-mals received an IR injection of 4% acetic acid or 0.9%saline solution on day 1. As previously shown, an IR injec-tion of 4% acetic acid produces colonic inflammation in ratsthat resembles many histological characteristics of humanulcerative colitis (19) (Figure 1).
Administration of Zolimid. Rats received either Zolimid(Cytos Pharmaceuticals, Durham, North Carolina, USA) orvehicle (0.9% saline solution). Zolimid was administeredeither orally by gavage (300 or 400 mg/kg) or rectally (200or 300 mg/kg) by enema beginning 6 hr after administrationof acetic acid on day 1, and thereafter three times a day forfive days. Seven groups were studied: group 1 (N 5 10)received vehicle (IR)/vehicle (IR); group 2 (N 5 10);vehicle (IR)/Zolimid (IR 300 mg/kg N 5 5 or gavage 400mg/kg, N 5 5); group 3 (N 5 20); acetic acid (IR)/vehicle(IR); group 4 (N 5 10); acetic acid (IR)/Zolimid (per os,400 mg/kg); group 5 (N 5 10); acetic acid (IR)/Zolimid(per as, 200 mg/kg); group 6 (N 5 10); acetic acid (IR)/Zolimid (IR, 200 mg/kg); and group 7 (N 5 10); acetic acid(IR)/Zolimid (IR, 300 mg/kg). The number of rats whoreceived acetic acid (IR) and vehicle (colitis “positive con-trol” group) is higher than other groups because we de-signed our study so as to have at least two colitis rats in eachexperimental week. This was done to make sure that ourmodel is reproducible and acetic acid induced colitis everyweek.
Administration of AEOL 11201. Rats received eitherAEOL11201 (Aeolus Pharmaceuticals, Research Triangle
Park, North Carolina, USA) or vehicle (20% PEG 400 110% ethanol). AEOL11201 was administered by intraperi-toneal (IP) injection (5 mg/kg) beginning 6 hr after admin-istration of acetic acid on day 1, and thereafter once a dayfor five days. Five groups were studied: group 1 (N 5 7)received 0.9% normal saline (IR)/0.9% normal saline (IP);group 2 (N 5 10), acetic acid (IR)/0.9% normal saline (IP);group 3 (N 5 5); 0.9% normal saline (IR)/AEOL11201(IP) 5 mg/kg; group 4 (N 5 10); acetic acid (IR)/AEOL11201 (IP) 5 mg/kg; group 5 (N 5 6); acetic acid(IR)/vehicle (20% PEG 400 1 10% ethanol, IP).
Macroscopic Evaluation of the Colon. Ninety-six hoursafter administration of acetic acid or vehicle (day 5), ani-mals were killed by using 45 mg/kg pentobarbital (Butler,Alsip, Illinois), and the entire colon was removed. Thecolon was opened, cleaned, laid flat, pinned on paraffinblocks, and longitudinally divided. The paraffin blocks wereimmediately placed in 10% buffered formalin. The colonwas blindly assessed for severity of colitis macroscopicallyon a scale adapted from Millar et al (20). Criteria forscoring ranged from 0 to 4: 0, no macroscopic change; 1,mucosal erythema alone; 2, mild mucosal edema and slightbleeding or small erosions; 3, moderate edema, bleedingulcers or erosions; and 4, severe ulceration/erosions,edema, and tissue necrosis, for a maximum score of 10.
Histologic Evaluation of Inflammation in the Colon. Thecolon was sectioned, processed, and stained with hematoxy-lin–eosin for histological analysis. Histologic slides werecoded to conceal the identity of the treatment groups andthe severity of tissue damage and the extent of inflamma-tion was evaluated by a gastrointestinal pathologist (Dr.Sherry Yong) who was blinded to their experimental regi-men. A previously reported inflammatory scoring systemwas used to assess each sample (9). In brief, eight histolog-ical parameters were assessed for each colonic sample.Each individual parameter was scored on an ascendingscale of 0 to 4 on the basis of severity and/or extent (area)of involvement of the mucosal wall or a combination ofseverity and extent. The eight parameters are as follows: (1)vascular dilation (score based on extent), (2) edema (com-bination of extent and severity), (3) epithelial cell loss fromnecrosis (extent), (4) cellular mucin depletion (extent), (5)neutrophil infiltration, (6) eosinophil infiltration, and (7)mononuclear cell infiltration (these three a combination ofextent and severity), and (8) fibrosis (extent). For extent,scoring was as follows: ,25%, 1; 26–50%, 2; 51–75%, 3;and .76%, 4. Scores for severity and extent were usuallyidentical; however, when these scores differed, estimatedaverage was used. Thus, in the absence of any abnormalityin the colon, the score was 0 and for the most severe colonicinflammation, the score was 32 (8 3 4). A histology score of4 or greater was considered colitis, while a score of 12 orgreater was considered severe colitis.
Measurement of Myeloperoxidase Activity in ColonicTissue. Mucosal scrapings were obtained from the colon formeasurement of MPO activity. Tissue samples were as-sessed biochemically for the neutrophil marker enzymeMPO (4), according to a previously reported method (21).The MPO level is a sensitive and specific index of neutro-phil infiltration and was used as an index for inflammation.A mucosal sample was obtained by scraping the colonicmucosa. The tissue was snap frozen at 270°C for subse-
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Fig 1. Representative histological slides from a rat receiving saline enema (control, A), acetic acid treatment (colitis, B), aceticacid and Zolimid enemas 300 mg/kg (C), or acetic acid enema and AEOL11201 IP (D). The colon was cut, embedded inparaffin and then stained with H&E (3100). Note distortion of crypt architecture, loss of epithelial cells with ulceration, andgoblet cell depletion with inflammatory infiltration in acetic acid-treated rats (B). The histological changes were significantlyimproved by either Zolimid (C) or AEOL11201 therapy (D).
Fig 1. (Continued.)
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quent analysis. The tissue was thawed, homogenized in 50mmol/liter potassium phosphate buffer (pH 6.0) (SigmaChemicals, St. Louis; Missouri, USA) and sonicated in anice water bath. After centrifugation (20,000g) for 10 min at4°C, the supernatant was discarded and 50 mmol/liter po-tassium phosphate buffer containing 0.5% hexadecyltri-methylammonium bromide (HTAB) (Sigma) was added tothe pellet. The mixture was homogenized for 30 secs, di-luted with 50 mmol/liter dipotassium phosphate and HTAB(1 g/5 ml), and sonicated for 30 secs on an ice bath. Theenzyme activity was determined spectrophotometrically us-ing a plate reader (Ceres 900). The enzyme reaction wasstarted by mixing the sample (7 ml) with 200 ml of O-dianisidine dihydrochloride (Sigma) in a 96-well plate. Theabsorbance was read at 460 nm over a period of 2 min at30-sec intervals. Data were expressed as the change inabsorbance over time. Total cellular protein was measuredusing the Bradford microprotein assay (Bio-Rad, Rich-mond, California, USA). MPO activity data are presentedas units per milligram of protein.
Clinical Signs. All rats were evaluated twice a day for thepresence and severity of diarrhea and rectal bleeding (clin-ical evidence of colitis). Each rat was also weighed daily. Aclinical activity index was calculated using the followingscales: For weight loss: 0 5 weight loss of 0–5%; 1 56–10%; 2 5 11–19%; 3 5 20–25%; and 4 5 $26%. For Ndiarrhea: 0 5 pellet and normal; 1 5 loose stool; and 2 5watery stool. For blood: 0 5 no blood; 1 5 spotting; and2 5 gross blood. Maximum possible score for activity indexwas 8.
Statistical Analysis. The values for histologic scores,macroscopic scores, and clinical activity index scores fromthe control and experimental groups were compared usingthe Mann-Whitney U test (nonparametric analyses). TheMPO data were normally distributed and analyzed usingStudent’s t test (parametric analyses). Data are presentedeither as means 6 SEM (for parametric data) or box plots(for non-parametric data). In the box plots, the median isdenoted by the center horizontal line. The bottom and topof the box, respectively, show the 25% and 75% rankingsand therefore the interquartile range. The 10% and 90%rankings are denoted by the lower and upper whiskers,outliers are denoted by circles. The median line is notvisible on the graph if the median is very close to or equalto the 25 or 75 quartile. Results were considered statisticallysignificant at P , 0.05.
These studies were approved by the animal care commit-tees at both Loyola University Medical Center and HinesVA Hospital. Animals were housed and experiments werecarried out in a facility accredited by the American Asso-ciation for Accreditation of Laboratory Animal Care inaccordance with the “Guide for the Care and Use of Lab-oratory Animals,” prepared by the National Academy ofSciences and published by the National Institute of Health.
RESULTS
Effects of Zolimid on Acetic Acid-Induced Colitis.As expected, intrarectal administration of 1.5 ml of4% acetic acid produced colitis in rats (Figure 1).Acetic acid caused significant (P , 0.01) weight loss
and diarrhea in rats (Figure 2). Median score forclinical activity index was 0 for control rats and 6 forcolitis rats. Acetic acid also caused significant (P ,0.01) tissue injury demonstrated both macroscopi-cally (median score: controls 5 0; colitis 5 4) (Figure3) and microscopically (median score: controls 5 2:colitis 5 7) (Figure 4). Acetic acid caused significantneutrophil infiltration into the colonic mucosa (Fig-ure 1B) and tissue MPO levels were significantly (P ,0.01) increased in acetic acid treated rats (medianvalues controls 5 2.60; colitis 5 14.25 units/g protein)(Figure 5).
Zolimid enema (N 5 5) or gavage (N 5 5) did notcause any weight loss or diarrhea (median score 5 0)(Figure 2) and had no significant effects on the co-lonic histology (median score 5 2) in vehicle-treatedcontrol rats. Zolimid enema significantly improvedacetic acid induced colitis (Figure 1C) and dose de-pendently decreased clinical activity score (medianscore for 200 mg 5 4; median score for 300 mg 5 3)(Figure 2). Zolimid also dose dependently decreasedboth macroscopic damage (median score for 200mg 5 2; median score for 300 mg 5 1.5) (Figure 3)and histological score (median score for 200 mg 5 5;median score for 300 mg 5 4) (Figure 4). TissueMPO levels were also lower in rats treated withZolimid (median values for 200 mg 5 7.50; median
Fig 2. Effects of Zolimid on clinical activity index. The score wascalculated as described in Materials and Methods. Plots depict themedian (center horizontal line) and 10th (upper whisker), 25th(bottom of the box), 75th (top of the box), 90th (lower wisker)percentiles. Outliers are indicated by circles. Acetic acid signifi-cantly worsened the score (*P , 0.01 vs vehicle-treated rats).Zolimid enema dose-dependently and significantly decreased thescores (1P , 0.01 vs acetic acid treated rats). Unlike Zolimidenema, Zolimid 200 mg/kg gavage had no effect, but the 400 mg/kgdose significantly decreased scores for clinical activity index.
score for 300 mg 5 3.45 units/g protein) (Figure 5).The beneficial effects of Zolimid enema were moremarked at 300 mg/kg and its effects reached statisticalsignificance for all parameters of tissue injury includ-ing histological scores and MPO levels. Zolimid ga-
vage also improved colitis but its effects appear to beless than Zolimid enema, and higher doses of intra-gastric Zolimid (400 mg/kg) were required for thera-peutic effects. Zolimid gavage (400 mg/kg) signifi-cantly decreased clinical activity index (median scorefor 200 mg 5 5; median score for 400 mg 5 4) (Figure2), macroscopic damage (median score for 200 mg 52; median score for 400 mg 5 2.65) (Figure 3),histological score (median score for 200 mg 5 8.5,median score for 400 mg 5 3.5) (Figure 4) and MPOlevels (median level for 200 mg 5 3.65, median levelfor 400 mg 5 2.65) (Figure 5).
Effects of AEOL11201 on Acetic Acid-Induced Co-litis. AEOL11201 (N 5 5) did not cause any weightloss or diarrhea in vehicle-treated rats (median scorefor vehicle and AEOL11201 5 0) (Figure 6). It hadno significant effects on the colon of vehicle-treatedrats that received saline enema (Figures 7–9).AEOL11201 improved acetic acid-induced colitis(Figure 1D). AEOL11201 significantly decreasedclinical activity index (median score for colitis 5 6; forAEOL11201 5 3) (Figure 6), macroscopic damage(median score for colitis 5 6; for AEOL11201 5 2)(Figure 7), histological score (median score for coli-tis 5 16; for AEOL11201 5 8) (Figure 8), and MPOlevels (median value for colitis 5 9.42; forAEOL11201 5 1.275) (Figure 9).
DISCUSSION
Ulcerative colitis is a chronic inflammatory boweldisease characterized by acute episodes of inflamma-
Fig 3. Effect of Zolimid on macroscopic changes in acetic acid-treated rats. Macroscopic score was calculated as described inMaterials and Methods. Data are presented as box-and-whiskerplots as described in Figure 2 legend. Zolimid enema dose-dependently and significantly improved macroscopic changes in-duced by acetic acid. The effect of Zolimid gavage was less markedand the improvement reached statistical significance only at 400mg/kg dose. *P , 0.05 vs controls; 1P 5 0.05 vs acetic acid.
Fig 4. Effect of Zolimid on histological changes. Histological scorewas calculated as described in Materials and Methods. Data arepresented as box-and-whisker plots as described in Figure 2 legend.Zolimid enema dose-dependently improved histological changesinduced by acetic acid. This improvement reached statistical sig-nificance at 300 mg/kg dose. Zolimid 200 mg/kg gavage had noeffect on histological scores, but a dose of 400 mg/kg significantlydecreased the score. P 5 0.05 vs controls; 1P 5 0.05 vs aceticacid.
Fig 5. Effect of Zolimid on MPO levels. Data are presented asmeans 6 SEM. Zolimid enema and gavage dose-dependently andsignificantly decreased MPO levels. The effects of Zolimid gavageand enema were similar. P 5 0.05 vs controls; 1P 5 0.05 vs aceticacid.
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tion of colonic mucosa with tissue damage interp-persed with inactive and quiescent periods. Duringthe active periods episodes, patients with UC havetroublesome symptoms of bloody diarrhea, abdomi-nal cramps, urgency, and weight loss; in contrast theyare almost asymptomatic during quiescent periods.Hence the goals of therapy are to abort active inflam-mation and to initiate tissue repair during the acutephase of the disease and then maintain remission andthe quiescent phase by preventing recurrence of theacute phase (1). Unfortunately there is no universallysafe and effective agent to achieve these therapeuticgoals. The available agents such as sulfasalazine/mesalamine or corticosteroids are neither universallyeffective nor tolerated by all patients. Indeed, as manyas 40–50% of patients with IBD are either refractoryto the current medications or develop significant tox-icity and side effects (1).
The lack of an optimal therapeutic agent for treat-ment of UC is not surprising, since the etiology of UCis not known. Nonetheless recent studies have signif-icantly improved our understanding of the pathogen-esis of tissue damage in UC. For example, it is nowaccepted that neutrophil-derived reactive oxygen spe-cies (ROS) are major mediators of the tissue injury inUC (2–6). Hence, antioxidants could potentially pre-vent and/or ameliorate tissue damage in patients withUC.
In order to determine if antioxidants are useful in
the treatment of UC, one needs to evaluate theantiinflammatory effects of a well-tolerated, nontoxic,yet very potent and specific antioxidant. The majorityof available agents with antioxidant activity are eithernot specific (eg, sulfasalazine) or are not suitable foruse in man (eg, SOD and catalase). However, thereare several newly discovered, specific antioxidantsthat can be potentially useful in the treatment ofpatients with UC. Two such agents are Zolimid andAEOL11201.
Zolimid is a form of the aminoacid L-histidine withwell-established antiinflammatory and antioxidant ac-tivities (29–33). L-Histidine has been shown to be ascavenger of both the hydroxyl radical and singletoxygen (O2) in several in vitro and in vivo studies(20–28). It is believed that the antioxidant character-istics of histidine are largely responsible for its anti-inflammatory effects. AEOL11201 is a manganeseporphyrin with well-established antioxidant activity.AEOL11201 is a potent inhibitor of lipid peroxidationwith negligible superoxide dismutase activity, and itinhibits iron/ascorbate-mediated lipid peroxidation ofrat brain homogenates with an IC50 of 0.15 mM (22,23). It should also be noted that histidine has beenwidely used as a nutritional supplement with no ap-parent toxicity or side effects. Hence, Zolimid andAEOL11201 can be potentially useful in the treat-ment of ROS-mediated inflammatory disorders suchas UC.
One of the most commonly used approaches toevaluate the efficacy and tolerability of a new phar-macological agent is use of animal models. Indeed,the therapeutic efficacy of many established pharma-cological agents currently used in treatment of UCwere initially tested in animal models of colitis (34).One such model is acetic acid-induced colitis in rats,which has been widely used for this purpose, but theacetic acid-induced colitis model should be used totest antioxidants if tissue injury in this model is me-diated by neutrophil-derived ROS. Indeed, we havepreviously demonstrated that tissue damage in ourmodel of acetic acid-induced colitis is mediated byneutrophil-derived ROS. For example, we demon-strated that there is a high level of ROS in theinflamed colonic tissue of acetic acid-treated rat andthat the source of ROS is PMN since azide (a MPOinhibitor) significantly decreased ROS levels. Fur-thermore, we have shown that tissue MPO level,which is a reliable marker of PMN infiltration, isincreased in colonic tissue five days following aceticacid injection. Finally, we have noted mucosal PMNinfiltration and crypt abscess in colonic mucosa of
Fig 6. Effect of AEOL11201 on clinical activity index. AEOL11201significantly decreased scores of clinical activity index in acetic acidtreated rats. The score was calculated as described in Materials andMethods. The vehicle is PEG 20% 1 ethanol 10%. *P , 0.05 vscontrols; 1P 5 0.05 vs acetic acid.
acetic acid treated rats when colon specimens wereexamined histologically.
In the present study, we evaluated the effects ofZolimid and AEOL11201 in acetic acid-induced co-
litis in the rat. We demonstrated that Zolimid (giveneither rectally or intragastrically) and AEOL11201(given intraperitoneally) significantly improved coli-tis. This therapeutic benefit was noted clinically, mac-roscopically, and histologically. Both agents also sig-nificantly decreased neutrophil infiltration into thecolonic mucosa.
Our data also suggest that Zolimid was more effec-tive when given by enema. This suggests that a highconcentration of the compound at the site of inflam-mation is important for its beneficial therapeutic ef-fect. However, higher doses of intragastrically admin-istered Zolimid was also effective, indicating that thecompound can still be used orally in patients with UC.This observation is not surprising and is similar toprior studies. For example, mesalamine is effectivewhen given either rectally or orally, but the effectivedose is lower when it is given rectally compared tooral route.
It should be noted that the criteria used in thecurrent study to evaluate the beneficial effects ofZolimid and AEOL11201 are clinically relevant forhuman studies. An effective agent must improve co-litis clinically, endoscopically (macroscopic appear-ance of colonic mucosa), and histologically, and itshould also decrease neutrophil infiltration. Zolimidand AEOL11201 fulfilled all of these requirements.However, it remains to be seen whether Zolimid orAEOL11201 is beneficial in treatment of UC in man.Our present study suggests that Zolimid and
Fig 7. Effect of AEOL11201 on macroscopic changes in the coloninduced by acetic acid. Macroscopic score was calculated as de-scribed in Materials and Methods section. Data are presented asbox-and-whisker plot as described in Figure 2 legend. AEOL11201significantly improved macroscopic changes induced by acetic acid.*P , 0.05 vs controls; 1P 5 0.05 vs acetic acid.
Fig 8. Effect of AEOL11201 on histological changes in the coloninduced by acetic acid. Histological score was calculated as de-scribed in the methods section. Data are presented as box-and-whisker plots as described in Figure 2 legend. AEOL11201 signif-icantly improved histological changes induced by acetic acid. *P ,0.05 vs controls; 1P 5 0.05 vs acetic acid.
Fig 9. Effect of AEOL11201 on MPO levels in the colon of aceticacid treated rats. Data are presented as box-and-whisker plots asdescribed in Figure 2 legend. AEOL11201 significantly decreasedMPO levels. *P , 0.05 vs controls; 1P 5 0.05 vs acetic acid.
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AEOL11201 are potent antiinflammatory agents andthey should now be evaluated in patients with UC.
ACKNOWLEDGMENTS
Authors are grateful to Ms. Mary Mclernon for preparingthis manuscript.
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