ObjectiveTo investigate the efficacy of Xingpi capsules （XPC） in treating diarrhea-predominant irritable bowel syndrome （IBS-D） with spleen deficiency and elucidate its potential molecular mechanisms. MethodsA rat model of IBS-D with spleen deficiency was established by administering senna leaf in combination with restrained stress and swimming fatigue for 14 d. Ten specific pathogen free （SPF）-grade healthy rats were used as the normal control group. After successful modeling， SPF-grade rats were randomly divided into a model group， a pinaverium bromide group （1.5 mg·kg^-1）， and low- and high-dose XPC groups （0.135 and 0.54 g·kg^-1）， with 10 rats in each group. Rats in the normal control group and the model group were given distilled water by gavage， while the remaining groups were administered corresponding drug solutions by gavage once a day for 14 consecutive days. The rat body weights and fecal condition were observed every day， and the Bristol score was recorded. Enzyme-linked immunosorbent assay （ELISA） was used to determine the levels of 5-hydroxytryptamine （5-HT） in serum and colon tissue. Transmission electron microscopy was used to observe the microvilli and tight junctions in the colon. The integrity of the colonic barrier， intestinal motility， and expression of related pathway proteins were evaluated by hematoxylin-eosin （HE） staining， immunohistochemistry， and Western blot. ResultsCompared with those in the normal control group， rats in the model group showed a significantly decreased body weight and increased diarrhea rate， diarrhea grade， and Bristol score （P<0.01）. HE staining revealed incomplete colonic mucosa in the model group， with evident congestion and edema observed. Electron microscopy results indicated decreased density and integrity of the colonic barrier， shedding and disappearance of microvilli， and significant widening of tight junctions. The expression levels of colonic tight junction proteins Occludin and Claudin-5 were downregulated （P<0.01）， and the levels of 5-HT in serum and colon tissue were elevated （P<0.01）. The small intestine propulsion rate significantly increased （P<0.01）， and the expression of contractile proteins Ras homolog family member A （RhoA） and Rho-associated coiled-coil containing protein kinase 2 （ROCK2） in colon and phosphorylation of myosin light chain （MLC₂₀） were upregulated （P<0.01）. Compared with the model group， the treatment groups showed alleviated diarrhea， diarrhea-associated symptoms， and pathological manifestations of colon tissue to varying degrees. Specifically， high-dose XPC exhibited effectively relieved diarrhea， promoted recovery of colonic mucosal structure， significantly reduced congestion and edema， upregulated expression of Occludin and Claudin-5 （P<0.01）， decreased levels of 5-HT in serum and colon tissue （P<0.05，P<0.01）， significantly slowed small intestine propulsion rate （P<0.01）， and significantly downregulated expression of contractile proteins RhoA and ROCK2 in colon and phosphorylation of MLC₂₀ （P<0.05，P<0.01）. ConclusionXPC effectively alleviates symptoms of spleen deficiency and diarrhea and regulates the secretion of brain-gut peptide. The characteristics of XPC are mainly manifested in alleviating IBS-D with spleen deficiency from the aspects of protecting intestinal mucosa and inhibiting smooth muscle contraction， and the mechanism is closely related to the regulation of the 5-HT-RhoA/ROCK2 pathway expression.

A 2-year-old boy was admitted to Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine in Nov 30^th, 2018, due to polydipsia, polyphagia, polyuria accompanied with increased glucose levels for more than 2 weeks. He presented with symmetrical short stature [height 81 cm (－2.2 SD), weight 9.8 kg (－2.1 SD), body mass index 14.94 kg/m² (P₁₀-P₁₅)], and with no special facial or physical features. Laboratory results showed that the glycated hemoglobin A1c was 14%, the fasting C-peptide was 0.3 ng/mL, and the islet autoantibodies were all negative. Oral glucose tolerance test showed significant increases in both fasting and postprandial glucose, but partial islet functions remained (post-load C-peptide increased 1.43 times compared to baseline). A heterozygous variant c.1366C>T (p.R456C) was detected in GATA6 gene, thereby the boy was diagnosed with a specific type of diabetes mellitus. The boy had congenital heart disease and suffered from transient hyperosmolar hyperglycemia after a patent ductus arteriosus surgery at 11 months of age. Insulin replacement therapy was prescribed, but without regular follow-up thereafter. The latest follow-up was about 3.5 years after the diagnosis of diabetes when the child was 5 years and 11 months old, with the fasting blood glucose of 6.0-10.0 mmol/L, and the 2 h postprandial glucose of 17.0-20.0 mmol/L.
Male ; Child ; Humans ; Child, Preschool ; Infant ; Diabetes Mellitus, Type 2/complications* ; Mutation, Missense ; C-Peptide/genetics* ; China ; Insulin/genetics* ; Glucose ; Blood Glucose ; GATA6 Transcription Factor/genetics*