Mb. Grisham et al., SULFASALAZINE OR ENTERAL DIETS CONTAINING FISH-OIL OR OLIGOSACCHARIDES ATTENUATE CHRONIC COLITIS IN RATS, Inflammatory bowel diseases, 2(3), 1996, pp. 178-188
Recent studies have suggested that n-3 fatty acids from fish oil (FO)
as well as short-chain fatty acids may attenuate some of the gut injur
y and inflammation-associated ulcerative colitic (UC). The objectives
of this study were to (a) assess the antiinflammatory activity of sulf
asalazine (SAZ), a drug known to be effective in the treatment of huma
n UC in a model of chronic granulomatous colitis in rats and (b) deter
mine whether enteral diets supplemented with either FO or two indigest
ible oligosaccharides (fructooligosaccharide, FOS; xylooligosaccharide
, XOS) could attenuate the inflammation observed in a model of chronic
granulomatous colitis. In one series of experiments, female Lewis rat
s were randomized into three groups consisting of a sham-operated cont
rol group, a colitic group, and a colitic group in which rats were giv
en oral sulfasalazine (SAZ) immediately after induction of colitis and
continued for 3 weeks. Chronic granulomatous colitis with liver and s
pleen inflammation was induced by subserosal (intramural) injection of
purified peptidoglycan-polysaccharide (PG/PS) into the distal colon.
Sham-operated rats were injected with human serum albumin. All rats re
ceived standard lab chow. In a second series of experiments, female Le
wis rats were randomized into six groups consisting of four colitic gr
oups fed enteral diets, a colitic group fed chow, and a sham-operated
group fed a control enteral diet. Enteral diets (300 kcal/kg/day) cont
ained either FO, FOS/gum arabic, XOS/gum arabic, or no bioactive ingre
dient (control diet). ALL rats were fed for 1 week before induction of
colitis. Rats consumed the diets for 3 additional weeks before being
killed. SAZ significantly attenuated the PG/PS-induced increases in my
eloperoxidase (MPO) activity as well as significantly reduced the PG/P
S-induced increases in liver and spleen weights. Control (enteral diet
) as well as the FO and XOS diets significantly attenuated the increas
e in colon weight when compared with chow-fed rats. We also found that
the FO and XOS diets significantly attenuated the PG/PS-induced incre
ases in colonic MPO activity and colon weight. The FOS and XOS diets s
ignificantly attenuated the PG/PS-induced increases in liver weights w
hen compared with PG/PS + chow-fed animals. The antiinflammatory activ
ity of these diets was confirmed by means of histological inspection s
howing an inhibition of inflammation and maintenance of crypt cell int
egrity. These results demonstrate that a complete enteral diet supplem
ented with either FO, FOS, or XOS exhibited antiinflammatory activity
that was similar in efficacy to the known antiinflammatory drug SAZ in
this model of colitis.