Effects of Rheum tanguticum polysaccharide on TNBS -induced colitis and CD4+T cells in rats.
OBJECTIVE
To study the effects of Rheum tanguticum polysaccharide(-1) (RTP(-1)) on ulcerative colitis in rats induced by 2, 4, 6-trinitrophene sulphonic acid (TNBS) and their possible mechanism.


METHODS
RTP1 (200 mg.kg(-1), i.g.) extracted from Rheum tanguticum Maxim. ex Regel was administrated to rats with colitis induced by TNBS for 5 d, 7 d, 10 d and 14 d, respectively. The effects of RTP1 and dexamethasone (DX, 0.2 mg.kg(-1), i.g.) were contrastively investigated. The MPO level and SOD activity were determined by chromatometry. The expansion and protein expression of CD4+T lymphocytes isolated from colon mucosae and mesenteric lymph nodes of colitis rats were performed by immunohistochemical analysis and Western-blot methods.


RESULTS
Treatments of RTP1 (200 mg.kg(-1), i.g.) significantly reduced diarrhea, mortality, colon mass, ulcer areas and MPO level in colon mucosae on days 5, 7, 10 and 14 (5.2+/-1.4, 5.4+/-0.7, 5.2+/-1.8, P<0.05. 3.4+/-0.8, P<0.01. 16.1+/-12.1, P<0.01. 31.8+/-8.6, 17.7+/-5.3, 12.7+/-4.1, P<0.05). The effects of RTP1 were similar to those noted above in DX group, but there were no immunosuppressive effects of DX in RTP(-1) group, such as body mass loss, thymus and spleen atrophy. The decreased number and down-regulated protein levels of CD4+T cells isolated from the colon of colitis rats treated with RTP1 were found.


CONCLUSIONS
RTP1 shows significantly protective effects but lower side effects on rats with colitis induced by TNBS. The mechanism may be due to the resistance to over expansion of CD4.
Liu
Li
L
Department of Pharmacology, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China.
Wang
Zhi-Peng
ZP
Xu
Chang-Tai
CT
Pan
Bo-Rong
BR
Mei
Qi-Bing
QB
Long
Yin
Y
Liu
Jia-Yun
JY
Zhou
Si-Yuan
SY
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects*; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy* / Q000276:immunology; D004365:Drugs, Chinese Herbal; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D009195:Peroxidase / Q000378:metabolism; D008517:Phytotherapy; D011134:Polysaccharides / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012250:Rheum; D013154:Spleen / Q000033:anatomy & histology; D013482:Superoxide Dismutase / Q000378:metabolism; D013950:Thymus Gland / Q000033:anatomy & histology; D014302:Trinitrobenzenesulfonic Acid
D004365:Drugs, Chinese Herbal; D011134:Polysaccharides; D014302:Trinitrobenzenesulfonic Acid; D009195:Peroxidase; D013482:Superoxide Dismutase