RESUMEN
OBJECTIVE To investigate the improvement effects of limonin on intestinal injury and intestinal flora disturbance in rats with ulcerative colitis （UC） and its mechanism. METHODS UC rat models were established， and 70 rats with successful modeling were randomly divided into model group， limonin low-， medium-， and high-dose groups （12.5， 25， 50 mg/kg）， and sulfasalazine group （positive control group，500 mg/kg）， with 14 rats in each group. Another 14 rats were selected as the control group. After modeling， each group was given the corresponding drug or equal amount of normal saline， once a day， for 2 weeks. Twenty-four hours after the last administration， the general condition of rats was observed and the body weight was measured， and colon tissue was collected for colonic mucosal damage index （CMDI） scoring； the levels of interleukin-1β （IL-1β）， IL-6 and tumor necrosis factor-α （TNF-α） in colon tissue were detected； the pathological changes of colon tissue were observed； the protein expressions of Claudin-1， Occludin， ZO-1， high mobility group protein B1 （HMGB1） and receptor for advanced glycation end products （RAGE） in colon tissue were detected； fecal 16S rRNA sequencing was used to detect the relative abundance of zhangxiaxia5287@163.com intestinal microbiota in rats. RESULTS Compared with the control group， the rats in the model group were in poor mental state， with darker fur， irritable mood， disordered arrangement of colon glands， inflammatory cell infiltration， cell necrosis and edema； CMDI score， the levels of IL-1β， IL-6 and TNF-α， protein expressions of HMGB1 and RAGE in colon tissue， the relative abundance of Proteobacteria and Bacteroidetes were significantly increased （P＜0.05）； body weight， the protein expressions of Claudin-1， Occludin and ZO-1 in colon tissue， the relative abundance of Firmicutes in the intestine were significantly decreased （P＜0.05）. Compared with the model group， general situation and pathological damage of colonic tissue in limonin groups were improved， the levels of the above indicators were significantly reversed （P＜0.05）， and in a dose-dependent manner （P＜0.05）； there was no significant difference in various indexes between sulfasalazine group and limonin high-dose group （P＞0.05）. CONCLUSIONS Limonin can improve intestinal injury and intestinal flora disturbance in UC model rats， the mechanism of which may be associated with the down-regulation of HMGB1/RAGE signaling pathway.
RESUMEN
OBJECTIVE：To prelimi narily investigate the possible mechanism of orazamide to prevent anti-tuberculosis drug-induced liver injury （ATB-DILI）. METHODS ：A total of 60 Kunming mice were randomly divided into blank group ，model group，positive control group [diammonium glycyrrhizinate 60 mg/（kg·d）]，orazamide low-dose ，medium-dose and high-dose groups [ 80，160，320 mg/（kg·d）]，with 10 mice in each group. Except for blank group ，other groups were given isoniazid [ 75 mg/（kg·d）]+rifampicin [ 75 mg/（kg·d）] for 14 days intragastrically to induce ATB-DILI model. At the same time ，administration groups were given relevant medicine intragastrically ，blank group and model group were given normal saline intragastrically. The administration volume was 20 mL/（kg·d），once a day ，for consecutive 14 days. The general conditions of the mice were observed and recorded every day ，such as growth and development ，mental and diet state. After last medication ，liver index was calculated ， and HE staining was adopted to observe pathological changes of liver tissue of mice. The positive expression of high mobility group protein B 1 （HMGB1） and NF-κ B in liver tissue were detected by streptavidin biotin-peroxidase complex （SABC） immuno- histochemistry. The serum levels of liver function indexes in serum ，the protein expression of advanced glycation end product receptor（RAGE）and TNF-α in liver tissue were detected by ELISA. RESULTS：Compared with blank group ，the growth and development of mice in the model group were slow ，and their appetite and spirit were poor. The liver index ，serum levels of TBIL ， DBIL，ALT，AST，ALP，TBA and γ-GT were increased significantly （P＜0.05）. Structural disorder of liver lobules ，degeneration and necrosis of liver cells and inflammatory cell infiltration were observed. The expression of HMGB 1，NF-κB，RAGE and TNF-α in liver tissue were elevated significantly （P＜0.05）. Compared with model group ，the general condition of mice were all improved to different extents in orazamide low-dose ，medium-dose and high-dose groups ，positive control group ，while liver index and above serum indexes were all decreased significantly （P＜0.05）. The pathological changes of liver tissue were all improved to different extents ，while the protein expression of HMGB 1，NF-κB，RAGE and TNF-α were all decreased significantly（P＜0.05）. The improvement of above indexes in orazamide high-dose group were all significantly better than orazamide low-dose and medium-dose groups （P＜0.05）；the levels of ALP and TBA in orazamide high-dose group were significantly lower than positive control group （P＜0.05）. CONCLUSIONS ：Orazamide can prevent ATB-DILI induced by isoniazid combined with rifampicin in mice，the mechanism of which may be associated with down-regulating the protein expression of HMGB 1 and RAGE in liver tissue and inhibiting the secretion of inflammatory factors.