Therapeutic effects of rectal administration of muscovite on experimental colitis in rats.
OBJECTIVE
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.
Chen
Yan
Y
Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Chen
Yi
Y
Liu
Wei-li
WL
Zhou
Tian-hua
TH
Cai
Jian-ting
JT
Du
Qing
Q
Wang
Liang-jing
LJ
Wu
Jia-Guo
JG
Si
Jian-min
JM
D000285:Administration, Rectal; D000538:Aluminum Silicates / Q000008:administration & dosage*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D001835:Body Weight / Q000187:drug effects; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003106:Colon / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage*; D019073:HT29 Cells; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D019804:Mesalamine / Q000008:administration & dosage; D055262:Mucin-2 / Q000235:genetics / Q000378:metabolism; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D000071165:Trefoil Factor-3; D014302:Trinitrobenzenesulfonic Acid; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D000538:Aluminum Silicates; D000893:Anti-Inflammatory Agents; D005765:Gastrointestinal Agents; D053583:Interleukin-1beta; C524628:Muc2 protein, rat; D055262:Mucin-2; D009479:Neuropeptides; C099037:TFF3 protein, rat; D000071165:Trefoil Factor-3; D014409:Tumor Necrosis Factor-alpha; C517971:muscovite; D019804:Mesalamine; D014302:Trinitrobenzenesulfonic Acid