Objective To investigate the therapeutic efficacy of
deoxycycline on ulcerative colitis in rats and it's possible mechanism.Methods
The ulcerative colitis rats model were induced by clusis of trinitrobenzene sulfonic acid/alcohol.The ulcerative colitis rats were treated by clusis with low-dose、mediate-dose and high-dose
deoxycycline (20、40 and 80 mg/kg body weight,once a day for 2 weeks).Colon constitution anatomical lesion was observed by macroscopy and mucosa histopathological changes were examined by optical microscopy.Myeloperoxidase (MPO)of colonic mucous membrane was determined.Messenger RNA (mRNA)levels of matrix metalloproteinase-2、9(MMP-2、9)were detected by hybridization in situ.The expression levels of type Ⅳ collagen were detected by immunohistochemical staining method.Results Compared with ulcerative colitis model group,it revealed that in deoxycycline-treated rats:colon constitution anatomical lesion and mucosa pathological change were relieved,the activity of MPO were decreased,mRNA levels of MMP-2、9 were down-regulated,and the degradation levels of type Ⅳ collagen protein were diminished.There was a significant difference between ulcerative colitis model group and each deoxycycline-treated group.Furthermore,the effect submitted to dose-dependent in a suitable dose range.Conclusion Deoxycycline can maintain the metabolism balance of
extracellular matrix(ECM)by inhibiting mRNA expression of MMP-2、9 and decreasing type Ⅳ collagen degradation,so that it has an apparent therapeutical effect on ulcerative colitis rats.