Qu-Yu-Jie-Du Decoction Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice by Modulation of Neutrophils and Macrophage Infiltration

BACKGROUND: Inflammatory bowel disease (IBD) is becoming a global disease. A percentage of IBD patients will not react to therapy or will lose their response. Qu-Yu-Jie-Du Decoction (QYJD) is a traditional Chinese medicine formula commonly used for intestinal diseases. It has been reported that QYJD has an anti-inflammatory effect, but the mechanism is not fully understood. In this study, we mainly evaluated the anti-inflammatory effect of QYJD and explored the possible mechanisms. METHODS: Twenty-four BALB/c mice were randomly divided into 4 groups according to their body weight, namely, the control group, the dextran sulfate sodium (DSS) group, the DSS + QYJD group, and the QYJD group. Mice were given 3% DSS drinking water freely, and at the same time, mice were given normal saline or QYJD (4.44 mg/g/d), respectively. Mental state, faeces, and weight were recorded every day. On the 10th day, the mice were sacrificed and collected for investigation. The length of the mice colon was measured. Histological analysis was used to detect the morphological changes in the colon. Immunohistochemistry was used to measure the infiltration of macrophages (F4/80, CD163) and neutrophils (Ly6G). Colorimetry was used to detect the myeloperoxidase (MPO) activity of colon tissues. ELISA was utilized to detect associated inflammatory cytokines and chemokines in colon tissues. RESULTS: QYJD alleviated the weight loss and colitis symptoms of mice caused by DSS. QYJD fought against the shortening of the intestine caused by DSS; that is, it improved the decline of intestinal compliance in mice and had a protective effect on colon tissues. The mechanisms were related to downregulating macrophages and neutrophils in colon tissues of infiltration. Besides, QYJD simultaneously reduced the activity of myeloperoxidase activity (MPO) and the contents of IL-1β, IL-6, TNF-α, TGF-β, CCL2, and CXCL2 in colon tissues. CONCLUSIONS: QYJD can ameliorate DSS-induced colitis in mice and the mechanism is connected with a reduction in neutrophil and macrophage infiltration.