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.

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.

Use of difenoximide (SC-26100) for narcotic detoxification: a preliminary tolerance and efficacy study.

Difenoximide (SC-26100) is closely related to the antidiarrheal agent, diphenoxylate, which is a chemical congener of meperidine. It has been shown to have a greater ability than methadone to suppress opiate withdrawal in addicted mice, and it has produced less physical dependence than morphine and methadone in laboratory animals. In this study difenoximide was administered to nine active heroin addicts. A dose of 4 mg administered 4 times per day for 3 days effectively suppressed opiate withdrawal, while a dose of 8 mg produced symptoms resembling those of narcotic excess in subjects who had recently self-administered heroin. No side effect were observed at the therapeutic dosage level, and the drug was well accepted by subjects. Difenoximide was shown to be a potentially useful narcotic treatment agent in this impatient study.