Rhubarb extract rebuilding the mucus homeostasis and regulating mucin-associated flora to relieve constipation.

In clinical trials, rhubarb extract (Rb) was demonstrated to efficiently alleviate constipation. We would like to find out the underlying mechanism of rhubarb relieving constipation. However, there are few studies on the effects of rhubarb on colonic mucus secretion and constipation. The aim of this study was to investigate the effects of rhubarb on colonic mucus secretion and its underlying mechanism. The mice were randomly divided into four groups. Group I was the control group and Group II was the rhubarb control group, with Rb (24 g/kg body weight [b.w.]) administered through intragastric administration for three days. Group III mice were given diphenoxylate (20 mg/kg b.w.) for five days via gavage to induce constipation. Group IV received diphenoxylate lasting five days before undergoing Rb administration for three days. The condition of the colon was evaluated using an endoscope. Particularly, the diameter of blood vessels in the colonic mucosa expanded considerably in constipation mice along with diminishing mucus output, which was in line with the observation via scanning electron microscope (SEM) and transmission electron microscope (TEM). We also performed metagenomic analysis to reveal the microbiome related to mucin gene expression level referring to mucin secretion. In conclusion, Rb relieves constipation by rebuilding mucus homeostasis and regulating the microbiome.

M1 macrophages-derived exosomes miR-34c-5p regulates interstitial cells of Cajal through targeting SCF.

Slow transit constipation (STC) is a gastrointestinal disorder characterized by abnormal prolonged colonic transit time, which affects the life quality of many people. The decrease number of interstitial cells of Cajal (ICCs) is involved in the pathogenesis of STC. However, the molecular mechanism of loss of ICCs in STC remains unclear, making it difficult to develop new agents for the disease. In this study, we investigated the mechanism of decreasing ICCs in the pathogenesis of STC. We constructed the STC model rats by using atropine and diphenoxylate. A series of methods were used including immunofluorescence and immunochemistry staining, western blot, qRT-PCR, exosomes extraction and exosomes labeling. The results indicate that ICCs decreased in the STC rats accompanied with the macrophages activation. Further studies suggested that macrophages decreased the cell viability of ICCs by secretion exosomes containing miR-34c-5p. miR-34c5p targeted the 3Ꞌ -UTR of stem cell factor(SCF) mRNA and regulated the expression of SCF negatively. In conclusion, we demonstrated a novel regulatory mechanism of ICCs cell viability in STC. We found that exosome miR-34c-5p mediate macrophage-ICCs cross-talk. M1 macrophages derived exosomes miR-34c-5p decreased ICCs cell viability by directly targeting SCF.

Median raphe stimulation-induced motor inhibition concurrent with suppression of type 1 and type 2 hippocampal theta.

This study investigated behavioral, anatomical and electrophysiological effects produced by electrical stimulation of posterior hypothalamic (PH) or median raphe (MR) nuclei, independently and during combined stimulation of both PH and MR. These three stimulation conditions were applied during spontaneous behavior in an open field and during PH stimulation-induced wheel running, while simultaneously recording hippocampal (HPC) field activity. An additional objective was to determine the effects of MR stimulation on Type 1 movement related theta and Type 2 sensory processing related theta. To achieve the latter, when behavioral studies were completed we studied the same rats under urethane anesthesia and then during urethane anesthesia with the addition of atropine sulfate (ATSO4). Here we demonstrated that electrical stimulation of a localized region of the MR nucleus resulted in a profound inhibition of both spontaneously occurring theta related motor behaviors and the theta related motor behaviors induced by electrical stimulation of the PH nucleus. Furthermore, this motor inhibition occurred concurrently with strong suppression of hippocampal theta field oscillations in the freely moving rat, a condition where the theta recorded is Type 2 sensory processing theta occurring coincidently with Type 1 movement related theta (Bland, 1986). Our results indicate that motor inhibition resulted from stimulation of neurons located in the mid central region of the MR, while stimulation in adjacent regions produced variable responses, including movements and theta activity. The present study provided evidence that the pharmacological basis of the suppression of Type 2 sensory processing HPC theta was cholinergic. However, MR inhibition of PH-induced wheel running was not affected by cholinergic blockade, which blocks Type 2 theta, indicating that MR stimulation-induced motor inhibition also requires the suppression of Type 1 theta.

Structure analysis and laxative effects of oligosaccharides isolated from bananas.

Banana oligosaccharides (BOS) were extracted with water, and then separated and purified using column chromatography. Gel penetration chromatography was used to determine the molecular weights. Thin layer chromatogram and capillary electrophoresis were employed to analyze the monosaccharide composition. The indican bond and structure of the BOS molecule were determined using Fourier transform infrared spectroscopy and nuclear magnetic resonance. Results showed that BOS were probably composed of eight ß-D-pyran glucose units linked with 1→6 indican bonds. The laxative effects of BOS were investigated in mice using the method described in "Handbook of Technical Standards for Testing and Assessment of Health Food in China." The length of the small intestine over which a carbon suspension solution advanced in mice treated with low-, middle-, and high-dose BOS was significantly greater than that in the model group, suggesting that BOS are effective in accelerating the movement of the small intestine.

Characterization of the maitotoxin-induced calcium influx pathway from human skin fibroblasts.

Maitotoxin (MTX), a water-soluble polyether obtained from the marine dinoflagellate Gambierdiscus toxicus increased intracellular calcium in a concentration-dependent manner in fibroblasts obtained from human skin. The effect of this toxin was both saturable and of high affinity, showing an apparent half activation constant of 450 fM. The toxin did not release intracellular calcium storage compartments nor did the release of these compartments with thapsigargin or ionomycin affect the toxin response. The toxin effect was reduced significantly by pre-incubating the cells with 0.1% trypsin for 30 min, strongly suggesting that the toxin receptor is a plasmalemmal protein. The effect of MTX was partially inhibited by diphenoxylate.

The peristaltic reflex in the rat ileum: evidence for functional mu- and delta-opiate receptors.

The potency order of opiate agonists at decreasing the rate of peristalsis in the rat isolated ileum was: difenoxin > loperamide > DADLE (D-Ala2-D-Leu5-enkephalin) > morphine > DSLET (D-Ser2,Leu5-Thr6-enkephalin). U-50488 (trans 3,4-dichloro-N-methyl-N-(2-(1-pyrrolidinyl) cyclohexyl) benzeneacetamide methane sulphonate) was inactive at 300 nM. Naloxone (400 nM) caused a significant 1.52-fold increase in the rate of peristaltic contractions and inhibited the effects of the active opiate agonists. The apparent pA2 values of naloxone were similar using difenoxin, loperamide and morphine as agonists, but the value was slightly, though significantly lower when DADLE was the agonist. It is suggested that the previously identified delta-opiate receptors of the rat small intestine have a functional role in suppressing the peristaltic reflex. The same response is subserved by mu-opiate receptors and either of these opiate-receptor subtypes could be activated by endogenous enkephalins.

Attempts to aid the adaptation of pelvic pouch before temporary ileostomy closure.

Most patients experience a high stool frequency immediately following the closure of the temporary ileostomy after total colectomy and ileoanal pouch reconstruction. Adaptation occurs within the ensuing weeks to reach a plateau in about three months. Increasing volumes of liquid nutrients were injected, twice daily for two months, into the pelvic pouch through a mucous ileal fistula proximal to the pouch before closing the temporary ileostomy. With this method the number of evacuations per 24 hours was significantly reduced during the first few weeks following the reestablishment of intestinal continuity, compared with a control group (average, 8.5 vs. 18.2, respectively). Patients also had better continence and less urgency to defecate. We suggest this technique in patients undergoing pelvic ileal reconstruction with temporary ileostomy.

Difenoxin and loperamide: studies on possible mechanisms of intestinal antisecretory action.

Experiments have been performed to determine whether the antisecretory (antidiarrhoeal) actions of difenoxin and loperamide are mediated by enteric neurones. An iso-osmotic perfusion solution was circulated around the lumen of the jejunum of anaesthetised rats. Vasoactive intestinal peptide was infused intra-arterially to induce net fluid secretion which was inhibited by difenoxin (ED50, 0.23 mg/kg) and loperamide (ED50, 0.5 mg/kg). However, neither were able to restore the fluid transport rate to the control level of absorption. The antisecretory effects of difenoxin (0.77 mg/kg) and loperamide (0.6 mg/kg) were blocked by the opiate receptor antagonist naloxone (2 mg/kg). Their effects were also abolished by pretreatment with the 5-HT synthesis inhibitor p-chlorophenylalanine (PCPA; 200 mg/kg; with desmethylimipramine given beforehand to protect noradrenergic nerves and enhance 5-HT depletion). The effect of difenoxin was blocked with methiothepin (1 mg/kg) and methysergide (30 micrograms/kg) but not ketanserin (30 micrograms/kg), ritanserin (30 mg/kg), ondansetron (10 micrograms/kg) or ICS 205-930 (3 mg/kg). None of the above 5-HT receptor antagonists modified the antisecretory effect of loperamide. The antisecretory effect of difenoxin but not loperamide was prevented by phentolamine (2 mg/kg) and by pretreatment with 6-hydroxy-dopamine (150 mg/kg total). It is concluded that both difenoxin and loperamide inhibit net fluid secretion by indirect mechanisms. It is proposed that the initial action is on enteric mu-opiate receptors and that this results in the release of 5-HT. In the case of difenoxin, the 5-HT may act on 5-HT1-like receptors to release noradrenaline.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of diphenoxylate hydrochloride and dl-15 methyl prostaglandin F2 alpha methyl ester on rat luteal cells].

Diphenoxylate hydrochloride (R1132) at concentrations of 10 and 20 micrograms/ml or dl-15 methyl-PGF2 alpha methyl ester (PG05) at levels of 5 and 10 micrograms/ml was shown to have no effect on progesterone secretion by luteal cells in vitro in the absence of hCG. A marked increase in progesterone level was elicited by hCG as high as 3-8 fold the original value. The steroidogenic response of luteal cells to hCG was inhibited by R1132 and PG05. R1132 at a daily dose of 10 mg/kg or PG05 at a daily dose of 0.1 mg/kg for 5 days showed no obvious effect on ovary progesterone secretion in pseudopregnant rat. However, treatment with R1132 10 mg/kg plus PG05 0.1 mg/kg resulted in a decrease in the progesterone production of ovary in vitro. R1132 and PG05 at doses of 50 mg/kg and 0.5 mg/kg, respectively, exhibited an inhibitory effect on the adenylate cyclase activity.

Effect of liquid diphenoxylate hydrochloride and atropine sulfate (Lomotil) instillations on dynamics and function of continent cecal urinary reservoirs.

We assessed the impact of twice daily instillations of 10 ml. liquid diphenoxylate hydrochloride and atropine sulfate (Lomotil) on the dynamics and function of continent urinary reservoirs constructed from intact cecum and ascending colon. Six patients were treated for 1 to 3 weeks at 3 to 8 months postoperatively. The treatments reduced the frequency of spontaneous reservoir contractions, as well as the basal and contraction pressures of the reservoirs. The reservoir capacities were increased modestly. These alterations in reservoir dynamics were accompanied by a decrease in the cramping characteristically associated with reservoir distension and increased intervals between reservoir catheterization. Two patients who had incontinence after initially successful operations regained continence during treatment. No systemic side effects were observed, although dilution of the drug may be required to prevent reservoir irritability. Diphenoxylate hydrochloride and atropine sulfate instillations may prevent acute and possibly long-term pressure-related complications of continent urinary reservoirs constructed from intact cecum and ascending colon.

Opioid action of the intestine: the importance of the intestinal mucosa.

Drug effects on the intestine are traditionally explained in terms of action on the muscle layers and the nerves that control them. This is particularly true in the case of the opioids but research starting two decades ago has identified the intestinal mucosa as the site of action of the antidiarrhoeal opioids. Continued research using the intestinal mucosa offers a fresh approach to solving some old problems. For example it could lead to more confident predictions to be made about the wanted and unwanted effects of opioid drugs on the intestine and may help to find better drug treatments for alleviating withdrawal diarrhoea in addicts. Eventually it may help to explain how the general process of opioid dependence occurs at a cellular level.

Evaluation of gastrointestinal motility using the hydrogen breath test.

The purpose of the study was to evaluate the validity of a model where intestinal transit is increased and decreased by motility modifying drugs. The measurement of breath hydrogen concentrations after ingestion of lactulose was used to estimate small intestinal transit time. After obtaining base-line values, eight healthy volunteers were pretreated on separate occasions with loperamide, diphenoxylate, metoclopramide and cisapride. Diphenoxylate caused a significant increase in small bowel transit time, whereas both metoclopramide and cisapride significantly shortened it. The H2 breath test therefore seems to accurately reflect the expected transit time. Loperamide did not alter significantly intestinal transit. Possibly this drug counteracts its own delaying influence on small bowel transit by hurrying gastric emptying. Alternatively, not enough time was allowed for it to exert its full effect.

Relationship between anti-diarrheal activity and binding to calmodulin.

Several neuroleptics known to bind to calmodulin were tested for anti-diarrheal activity and were compared with the opiate anti-diarrheals loperamide and diphenoxylate. All inhibited the intestinal fluid secretion induced by 16,16-dimethyl prostaglandin E2 and castor oil-induced diarrhea in rats as a function of dose, the order of potency being loperamide approximately equal to diphenoxylate greater than chlorpromazine greater than promethazine greater than amitriptyline. The opiates loperamide and diphenoxylate were found to compete with [3H]trifluoperazine binding to calmodulin in the presence of calcium. These opiates were approximately 3 times more potent inhibitors of [3H]trifluoperazine binding than chlorpromazine. A positive correlation between calmodulin binding and anti-diarrheal activity was demonstrated.

Gut propulsion in mice infected with Trichinella spiralis.

Previous investigators have shown that Trichinella spiralis increases intestinal motility and propulsion. We report here that primary infection with T. spiralis in the mouse increased gut propulsion, measured by the movement of nonabsorbable chromatography beads, on day 5 after infection but not 9 days after infection. Both cortisone acetate, an anti-inflammatory agent, and Lomotil, which reduced gut motility, could suppress the increase in gut propulsion seen 5 days after infection. The results suggest that early inflammation influences peristaltic activity and propulsion of intestinal contents.

Effect of chemical and pharmacological agents on the secretory activity induced by Escherichia coli heat-stable enterotoxin.

The effect of aspirin (ASP), chlorpromazine (CPZ), diphenoxylate (DP), ethylene glycol tetraacetate (EGTA), hydrocortisone (HC), loperamide (LPA), methylprednisolone (MP), phenotolamine mesylate (PTM), propranolol (PR), and trifluoperazine (TPZ) on the secretory activity induced by Escherichia coli heat-stable (ST) enterotoxin in infant mice was studied. LPA and DP, which are used therapeutically for diarrhea, did not inhibit the effect of ST enterotoxin; MP and HC, known inhibitors of cholera enterotoxin, and two adrenergic agents (PR and PTM) had no effect on ST-induced secretory activity. TPZ, EGTA, ASP, and CPZ caused a significant (P less than 0.05) decrease in the secretory activity induced by ST enterotoxin, CPZ, EGTA, and TPZ inhibited secretory activity induced by 8-bromoguanosine 3'5'-cyclic monophosphoric acid (8-BrcGMP), a cGMP analog.