Regulating effect of TongXie-YaoFang on colonic epithelial secretion via Cl- and HCO3- channel

Assessing the post-treatment therapeutic effect of tongxie in irritable bowel syndrome: a randomized controlled trial

Diarrhea predominant irritable bowel syndrome (IBS) is a highly relapsing gastrointestinal disorder decreasing the quality of life. Existing studies indicated that the therapeutic effects maintained for a period of time after the treatments were discontinued (post-treatment therapeutic effects or PTTE). In this study, we aim to assess the PTTE of tongxie. We performed a multiple center, controlled, double blind study of patients with IBS randomized to tongxie (n=120) or placebo (n=120) for 4 weeks and followed up for 57 weeks. The primary outcomes were abdominal pains and stool consistency. The secondary outcomes were pain frequency and stool frequency. Tertiary outcomes were adverse effects and global overall symptom. The outcome data were collected at days 1, 2, 3, weeks 1 and 4 during the treatment and at days 1, 2, 3, until week 57 during the post-treatment. Significantly more patients receiving tongxie were clinical responders to the primary and secondary endpoints from day 1 until the end of the treatment. The positive effects of tongxie were maintained until 17 to 25 weeks after tongxie was discontinued. The relapse-free probabilities in the tongxie group were significantly higher than those in the placebo group (P <.001). Twenty-five weeks after the therapies were discontinued could be considered as IBS natural history. During this period, an average of 53.8% - 56.3% of patients (pool tongxie and placebo data together) had IBS symptoms (pain scale ≥ 3, stool consistency ≥ 5). In particular, at the end of this study (week 61), 145 (54.2%) patients had IBS symptoms. Our results provide clinical insights into efficient and cost-effective management of refractory IBS, and lend support to the IBS management that the selection of a therapy should consider both its effectiveness during treatment and its PTTE after the treatment. Clinicaltrials.gov no: NCT02330029.

Regulation of Cl- Electrolyte Permeability in Epithelia by Active Traditional Chinese Medicine Monomers for Diarrhea

The epithelial layer, lining the inner surface of the mammalian alveolar, kidney, brain and colon, is a typical electrolyte transporting tissue. Large quantities of salt and fluid are actively moved from the mucosal side toward the blood vessel. Transepithelial salt re-absorption in epithelial tissues plays an important role in maintaining fluid homeostasis. In absorptive epithelium, fluid and salt flux is controlled by the machinery mainly composed of epithelial sodium channel, cystic fibrosis transmembrane conductance regulator, Na+-K+-2Cl- cotransporter, Na+/H+ exchanger, and Na+/K+-ATPase. Dysregulation of salt permeability across epithelium contributes to the pathogenesis of organ edema. In numerous ion transporters, epithelial Cl- transportation plays an important role in water secretion across epithelial tissues and regulation of body fluid content. Many traditional Chinese medicines treat diarrhea by regulating the Cl- electrolyte transport. We systematically summarized the recent progress regarding the traditional Chinese medicine on Cl- electrolyte transport in the intestinal epithelial tissues. The pharmaceutical relevance of developing advanced strategies to mitigate edematous disorders is also implicated. In conclusion, the crosstalk between Cl- electrolyte transport and active traditional Chinese medicine monomers may lead to the development of new strategies for diarrhea by manipulating the function and expression of ion channels.

Protective effect of Tongxie Yaofang formula on intestinal tissue of rats with acute radiation enteritis

AIM

To investigate the protective effect of Tongxie Yaofang formula on intestinal tissue of rats with acute radiation enteritis (RE) and to explore the underlying mechanisms.

METHODS

Forty-eight Sprague-Dawley (SD) male rats were randomly divided into four groups: A-D. Group A (n = 12) was given no treatment, while group B (n = 12), group C (n = 12), and group D (n = 12) underwent whole abdominal irradiation at a single dose of 10 Gy. At day 1 after irradiation, group A and group B were given distilled water, while group C were given Tongxie Yaofang formula and group D were given glutamine by gavage for 17 consecutive days. The general condition, defecation, and weight change of rats were daily observed. In each group, jejunal tissue was taken at 6 h after gastric lavage, and the morphology of intestinal tissue was observed under a light microscope. The content of nitric oxide (NO) in jejunal tissue was measured, and the protein contents of interleukin (IL)-6, IL-10, and tumor necrosis factor α (TNF-α) were determined by ELISA.

RESULTS

After gastric lavage, one rat died at day 3, and no death was found in all the other groups. Rats in group C and group D had different degrees of improvement in general condition and mucosanguineous feces. The body weight of rats in group C and group D increased significantly compared with that of group B (P < 0.05). Compared with group B, the contents of NO, IL-6, and TNF-α in group C and group D significantly decreased (P < 0.05). The levels of IL-10 in group C and group D were significantly higher than that in group B (P < 0.01).

CONCLUSION

Tongxie Yaofang formula has a protective effect on intestinal tissue of rats with acute RE possibly via mechanisms that may be related to decreasing the levels of NO, IL-6, and TNF-α in jejunum, increasing the content of IL-10, and reducing the inflammation in intestinal tissue.

Mucosa repair mechanisms of Tong-Xie-Yao-Fang mediated by CRH-R2 in murine, dextran sulfate sodium-induced colitis

AIM

To explore the significance of corticotropin-releasing hormone (CRH)-receptor (R)2 in mucosal healing of dextran sulfate sodium (DSS)-induced colitis and the effect of Tong-Xie-Yao-Fang (TXYF) on CRH-R2 expression and regulation.

METHODS

Ulcerative colitis was induced in mice by administration of 3% (w/v) DSS for 7 d. Once the model was established, mice were administered urocortin-2 (30 μg/kg), a peptide which binds exclusively to CRH-R2, or various doses of aqueous TXYF extracts (2.8-11.2 g/kg), a CRH-R2 antagonist Astressin (Ast)2B (20 μg/kg), Ast2B + Ucn2, or Ast2B with various doses of aqueous TXYF extracts for 9 d. Colonic mucosal permeability was then evaluated by measuring the fluorescence intensity in serum. The colitis disease activity index (DAI), histology, body weight loss and colon length were assessed to evaluate the condition of colitis. Terminal deoxynucleotidyl transferase dUTP nick-end labeling was used to detect apoptosis of the intestinal epithelial cells. The expression level of Ki-67 represented the proliferation of colonic epithelial cells and was detected by immunohistochemistry. The expression levels of inflammation cytokines IL-6, TNF-α and CXCL-1 were examined in colon tissues using real-time PCR and ELISA kits.

RESULTS

Compared with the DSS group, mice treated with the CRH-R2 antagonist Ast2B showed greater loss of body weight, shorter colon lengths (4.90 ± 0.32 vs 6.21 ± 0.34 cm, P < 0.05), and higher DAI (3.61 ± 0.53 vs 2.42 ± 0.32, P < 0.05) and histological scores (11.50 ± 1.05 vs 8.33 ± 1.03, P < 0.05). Additionally, the Ast2B group showed increased intestinal permeability (2.76 ± 0.11 μg/mL vs 1.47 ± 0.11 μg/mL, P < 0.001), improved secretion of inflammatory cytokines in colon tissue, and reduced colonic epithelial cell proliferation (4.97 ± 4.25 vs 22.51 ± 8.22, P < 0.05). Increased apoptosis (1422.39 ± 90.71 vs 983.01 ± 98.17, P < 0.001) was also demonstrated. The Ucn2 group demonstrated lower DAI (0.87 ± 0.55 vs 2.42 ± 0.32, P < 0.001) and histological scores (4.33 ± 1.50 vs 8.33 ± 1.03, P < 0.05). Diminished weight loss, longer colon length (9.58 ± 0.62 vs 6.21 ± 0.34 cm, P < 0.001), reduced intestinal permeability (0.75 ± 0.07 vs 1.47 ± 0.11 μg/mL, P < 0.001), inhibited secretion of inflammatory cytokines in colon tissue and increased colonic epithelial cell proliferation (90.04 ± 15.50 vs 22.51 ± 8.22, P < 0.01) were all observed. Reduced apoptosis (149.55 ± 21.68 vs 983.01 ± 98.17, P < 0.05) was also observed. However, significant statistical differences in the results of the Ast2B group and Ast2B + Ucn2 group were observed. TXYF was also found to ameliorate symptoms of DSS-induced colitis in mice and to promote mucosal repair like Ucn2. There were significant differences between the Ast2B + TXYF groups and the TXYF groups.

CONCLUSION

CRH-R2 activates the intestinal mucosal antiinflammatory response by regulating migration, proliferation and apoptosis of intestinal epithelial cells in colitis-induced mice, and plays an important antiinflammatory role. TXYF promotes mucosal repair in colitis mice by regulating CRH-R2.