Tong Xie Yao Fang relieves irritable bowel syndrome in rats via mechanisms involving regulation of 5-hydroxytryptamine and substance P

• Published in: World journal of gastroenterology : WJG Vol. 21; no. 15; pp. 4536 - 4546
• Main Authors: Yin, Yue, Zhong, Lei, Wang, Jian-Wei, Zhao, Xue-Ying, Zhao, Wen-Jing, Kuang, Hai-Xue
• Format: Journal Article
• Language: English
• Published: United States Baishideng Publishing Group Inc 21.04.2015
• Subjects: Animals; Animals, Newborn; Anti-Inflammatory Agents - pharmacology; Basic Study; Colon - drug effects; Colon - innervation; Colon - metabolism; Colon - physiopathology; Defecation - drug effects; Disease Models, Animal; Drugs, Chinese Herbal - pharmacology; Enteric Nervous System - drug effects; Enteric Nervous System - metabolism; Enteric Nervous System - physiopathology; Gastrointestinal Agents - pharmacology; Gastrointestinal Motility - drug effects; Hypothalamus - drug effects; Hypothalamus - metabolism; Hypothalamus - physiopathology; Irritable Bowel Syndrome - drug therapy; Irritable Bowel Syndrome - genetics; Irritable Bowel Syndrome - metabolism; Irritable Bowel Syndrome - physiopathology; Rats, Wistar; Serotonin - metabolism; Signal Transduction - drug effects; Substance P - genetics; Substance P - metabolism; Time Factors; Traditional Chinese medicine; Tong Xie Yao Fang; 5-hydroxytryptamine; Substance P; Irritable bowel syndrome
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.v21.i15.4536

To investigate whether the Chinese medicine Tong Xie Yao Fang (TXYF) improves dysfunction in an irritable bowel syndrome (IBS) rat model. Thirty baby rats for IBS modeling were separated from mother rats (1 h per day) from days 8 to 21, and the rectum was expanded by angioplasty from days 8 to 12. Ten normal rats were used as normal controls. We examined the effects of TXYF on defection frequency, colonic transit function and smooth muscle contraction, and the expression of 5-hydroxytryptamine (5-HT) and substance P (SP) in colonic and hypothalamus tissues by Western blot and RT-PCT techniques in both normal rats and IBS model rats with characterized visceral hypersensitivity. Defecation frequency was 1.8 ± 1.03 in normal rats and 4.5 ± 1.58 in IBS model rats (P < 0.001). However, the defecation frequency was significantly decreased (3.0 ± 1.25 vs 4.5 ± 1.58, P < 0.05), while the time (in seconds) of colon transit function was significantly increased (256.88 ± 20.32 vs 93.36 ± 17.28, P < 0.001) in IBS + TXYF group rats than in IBS group rats. Increased colonic smooth muscle tension and contract frequency in IBS model rats were significantly decreased by administration of TXYF. Exogenous agonist stimulants increased spontaneous activity and elicited contractions of colon smooth muscle in IBS model rats, and all of these actions were significantly reduced by TXYF involving 5-HT and SP down-regulation. TXYF can modulate the activity of the enteric nervous system and alter 5-HT and SP activities, which may contribute to the symptoms of IBS.