Pectic polysaccharides from Radix Sophorae Tonkinensis exhibit significant antioxidant effects.

Two pectic polysaccharides (WRSP-A2b and WRSP-A3a) have been obtained from Radix Sophorae Tonkinensis and comparatively investigated in terms of their physical properties and antioxidant activities. Monosaccharide composition, FT-IR, NMR and enzymatic analyses indicate that both WRSP-A2b (13.6 kDa) and WRSP-A3a (44.6 kDa) consist of homogalacturonan (HG), rhamnogalacturonan I (RG-I) and rhamnogalacturonan II (RG-II) domains, with mass ratios of 0.9:1.8:1 and 2.3:2.9:1, respectively. The RG-I domains were further purified and characterized. Results show that WRSP-A2b contains a highly branched RG-I domain, primarily substituted with α-(1→5)-linked arabinans, whereas WRSP-A3a contains a small branched RG-I domain mainly composed of ß-(1→4)-linked galactan side chains. WRSP-A3a exhibits stronger antioxidant activity in scavenging different radicals than WRSP-A2b, a finding that may be due to its higher content of GalA residues and HG domains. Our results provide useful information for screening natural polysaccharide-based antioxidants from Radix Sophorae Tonkinensis.

Bu-Zhong-Yi-Qi Granule Enhances Colonic Tight Junction Integrity via TLR4/NF-κB/MLCK Signaling Pathway in Ulcerative Colitis Rats.

BACKGROUND: Bu-zhong-yi-qi granule (BZYQ), a sort of Chinese herbal medicine, has exhibited therapeutic effects on ulcerative colitis (UC). However, the mechanism of BZYQ has not been fully clarified. This study was aimed at investigating the effects of BZYQ on UC rats model and at exploring its potential mechanism. METHODS: The UC rats were established by enema of trinitrobenzene sulfonic acid (TNBS). The therapeutic effects of BZYQ treatment were evaluated by disease activity index (DAI), colon macroscopic damage index (CMDI) scores, and histological observation. The mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-10 (IL-10) were measured by quantitative real time-polymerase chain reaction (qPCR). The expression of tight junction (TJ) proteins, occludin and claudin-1, in the colon was determined by Western blot and immunofluorescence. The expression of toll-like receptors 4 (TLR4), nuclear factor-kappa B (NF-κB), p-NF-κB, myosin light chain kinase (MLCK), MLC, and p-MLC levels in colon was determined by Western blot or qPCR. RESULTS: The results showed that BZYQ could attenuate DAI, CMDI, and histological inflammation. TJ proteins expression was decreased in UC rats, but treatment with BZYQ restored the expression of occludin and claudin-1. In addition, BZYQ administration ameliorated UC-associated increase in the production of TNF-α, IL-1ß, and the expression of TLR4, NF-κB, p-NF-κB, MLCK, MLC, and p-MLC, while BZYQ administration increased the production of IL-10. CONCLUSIONS: The therapeutic effect of BZYQ on UC is at least partially through regulation of the secretion of some inflammatory cytokines and improvement of TJ integrity via TLR4/NF-κB/MLCK pathway.

Effects of Fengliao-Changweikang in Diarrhea-predominant Irritable Bowel Syndrome Rats and Its Mechanism Involving Colonic Motility.

BACKGROUND/AIMS: This study was designed to investigate the effect of Fengliao-Changweikang (FLCWK) in diarrhea-predominant irritable bowel syndrome (IBS-D) rats and explore its underlying mechanisms. METHODS: IBS-D model rats were induced by neonatal maternal separation (NMS) combined with restraint stress (RS). In in vivo experiments, the model rats were randomly divided into 5 groups: NMS + RS, FLCWK (low dose, middle dose, and high dose), and pinaverium bromide. The normal control (no handling) rats were classified as the NH group. The therapeutic effect of FLCWK was evaluated by fecal characteristics, electromyographic response and abdominal withdrawal reflex scores. In in vitro experiments, the model rats were randomly divided into 2 groups: NMS + RS, FLCWK (middle dose), and no handling rats were used as the NH group. The differences in basic tension and ACh-induced tension of isolated colonic longitudinal smooth muscle strips (CLSMs) among the 3 groups were observed. In addition, different inhibitors (nifedipine, TMB-8, L-NAME, methylene blue, and 4-AP) were pretreated to explore the underlying mechanisms. RESULTS: In in vivo experiments, fecal characteristics, electromyographic response, and abdominal withdrawal reflex scores significantly improved in the FLCWK group, compared with the NMS + RS group. In in vitro experiments, the basic tension and ACh-induced tension of CLSMs in IBS-D rats were significantly inhibited by FLCWK. After pre-treatment with different inhibitors, the ACh-induced tension of CLSMs in each group showed no significant difference. CONCLUSIONS: FLCWK manifested curative effect in IBS-D rats by inhibiting colonic contraction. The underlying mechanisms may be related to regulatory pathway of nitric oxide/cGMP/Ca²âº and specific potassium channels.

Effects of Hemp seed soft capsule on colonic ion transport in rats.

AIM: To investigate the effect of Hemp seed soft capsule (HSCC) on colonic ion transport and its related mechanisms in constipation rats. METHODS: Sprague-Dawley male rats were randomly divided into three groups: normal group, constipation group and HSSC group. Rats in the constipation and HSSC groups were administrated loperamide 3 mg/kg per day orally for 12 d to induce the constipation model. Then, the HSSC group was given HSSC 0.126 g/kg per day by gavage for 7 d. The normal and constipation groups were treated with distilled water. After the treatment, the fecal wet weight and water content were measured. The basal short-circuit current (Isc) and resistance were measured by an Ussing Chamber. Besides the in vivo drug delivery experiment above, an in vitro drug application experiment was also conducted. The accumulative concentrations of HSSC (0.1 mg/mL, 0.5 mg/mL, 1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL, 10.0 mg/mL and 25.0 mg/mL) were added to the normal isolated colonic mucosa and the Isc was recorded. Further, after the application of either ion (Cl- or HCO3-) substitution, ion channel-related inhibitor (N-phenylanthranilic acid, glybenclamide, 4,4-diisothiocyano-2,2-stilbenedisulfonic acid or bumetanide) or neural pathway inhibitor [tetrodotoxin (TTX), atropine, or hexamethonium], the Isc induced by HSSC was also measured. RESULTS: In the constipation group, the fecal wet weight and the water content were decreased in comparison with the normal group (P < 0.01). After the treatment with HSSC, the fecal wet weight and the water content in the HSSC group were increased, compared with the constipation group (P < 0.01). In the constipation group, the basal Isc was decreased and resistance was increased, in comparison with the normal group (P < 0.01). After the treatment with HSSC, the basal Isc was increased (P < 0.05) and resistance was decreased (P < 0.01) in the HSSC group compared with the constipation group. In the in vitro experiment, beginning with the concentration of 1.0 mg/mL, differences in Isc were found between the experimental mucosa (with HSSC added) and control mucosa. The Isc of experimental mucosa was higher than that of control mucosa under the same concentration (1.0 mg/mL, P < 0.05; 2.5-25 mg/mL, P < 0.01). After the Cl- or HCO3- removal and pretreated with different inhibitors (cAMP-dependent and Ca2+-dependent Cl- channels, Na+-K+-2Cl- cotransporter (NKCC), Na+-HCO3- cotransporter or Cl-/HCO3- exchanger inhibitor), there were differences between experimental mucosa and control mucosa; the Isc of experimental mucosa was lower than that of control mucosa under the same concentration (P < 0.05). Meanwhile, after pretreatment with neural pathway inhibitor (TTX, atropine, or hexamethonium), there were no differences between experimental mucosa and control mucosa under the same concentration (P > 0.05). CONCLUSION: HSSC ameliorates constipation by increasing colonic secretion, which is mediated via the coaction of cAMP-dependent and Ca2+-dependent Cl- channels, NKCC, Na+-HCO3- cotransporter or Cl-/HCO3- exchanger.