Intervention Mechanism of Huangqintang on Intestinal Inflammation and Proliferation in Colitis-associated Colon Cancer / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the efficacy of Huangqintang on mouse models of colitis-associated colon cancer （CAC） and explore the mechanism of Huangqintang in regulating immune function and inflammatory response， inhibiting abnormal cell proliferation， and delaying or inhibiting CAC formation in CAC. MethodC57BL/6J mice were randomly divided into a normal group， model group， mesalazine group， and high- and low-dose Huangqintang groups according to body weight， with 12 mice in each group. Except for the normal group， the rest of the mice were given two intraperitoneal injections of 10 mg·kg-1 azomethane （AOM） and allowed to drink 1.5% dextran sodium sulfate （DSS） freely for seven days and water normally for two weeks. Then， two cycles of ''DSS-drinking water'' were repeated. During the administration of DSS， mice in the normal group and model group were given gavage in equal doses of pure water. Mice in the mesalazine group were given 150 mg·kg-1·d-1 mesalamine suspension for gavage， and mice in the high- and low-dose Huangqintang groups were given 18 and 9 g·kg-1·d-1 Huangqintang for gavage， respectively. Each group was given one dose daily until the end of three cycles. After the intervention， the body weight， colon length， and number of colon tumors in each group were measured， and disease activity index （DAI） scores were performed. The serum contents of interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， interleukin-4 （IL-4）， interleukin-10 （IL-10）， and gastrointestinal tumor marker carbohydrate antigen-199 （CA199） were detected by enzyme linked immunosorbent assay （ELISA）. The colonic lesions were observed by hematoxylin-eosin （HE） staining. The expression of proliferative cell-associated antigen （Ki67） was observed by immunohistochemistry. The expression of T lymphocyte subsets （CD3+， CD4+， CD8+， and CD49b+） in mouse plasma was detected by flow cytometry. Fluorescein isothiocyanate-D （FITC-D） content in mouse serum was detected by fluorescent labeling method. The Western blot method was used to detect the expression of Cyclin D1， cyclin-dependent kinase 2 （CDK2）， cyclin-dependent kinase 4 （CDK4）， and tightly junction-related Occludin and Claudin-1. ResultCompared with the normal group， the body weight of mice in the model group decreased. DAI score increased significantly， and the colon became shorter. Pro-inflammatory factors such as IL-6， TNF-α， and IL-1β increased， and IL-6 and TNF-α were significantly increased （P<0.05）. The inflammatory factor IL-4 （P<0.05） and IL-10 were significantly reduced， and the tumor marker CA199 was significantly increased （P<0.01）. HE staining showed that colon lesions， intestinal mucosal epithelial defects with a large number of inflammatory infiltrates， serious crypt structure damage， and glandular arrangement disorder were observed in the model group. Ki67 positive granules were expressed in large areas of colonic tissue. The serum CD4+ and CD4+/CD8+ of mice in the model group decreased significantly （P<0.05）， and CD8+ increased significantly （P<0.05）. The plasma content of FITC-D in the model group was significantly increased （P<0.05）， and the expression of Cyclin D1， CDK2， and CDK4 proteins in colon tissue was significantly increased （P<0.05， P<0.01）. In addition， the expression of Occludin and Claudin-1 was significantly decreased. Compared with the model group， the body weight of mice in the mesalazine group and the high- and low-dose Huangqintang groups increased. DAI score decreased， and the colon became longer. IL-6， TNF-α， and IL-1β expression decreased （P<0.05， P<0.01）， but there was no significant change in IL-4 and IL-10. The content of CA199 was significantly reduced （P<0.05）， and the colomatoid lesions and inflammatory infiltrates were reduced in the mesalazine group and the Huangqintang group. The crypt structure damage was lighter， and the positive expression of Ki67 was reduced. CD4+， CD4+/CD8+， and CD49b+ increased， and the difference was not statistically significant. FITC-D content decreased （P<0.05）. The expression of Cyclin D1， CDK2， and CDK4 decreased （P<0.05， P<0.01）， and Claudin-1 and Occludin protein expression increased in the high-dose Huangqintang group （P<0.05）. ConclusionHuangqintang has a certain delay and inhibitory effect on AOM/DSS-induced inflammatory cancer transformation， and its mechanism of action may be related to regulating immune function and inflammatory response， inhibiting the release of pro-inflammatory factors， repairing damaged intestinal barriers， inhibiting abnormal proliferation of colon cells， and intervening in the formation and development of CAC colon tumors.