Effect of areca on contraction of colonic muscle strips in rats

Arecoline alleviated loperamide induced constipation by regulating gut microbes and the expression of colonic genome

This study aimed to investigate the effects of arecoline on constipation by intervening at different times to explore its preventive and therapeutic effects. Symptoms related to constipation, gut microbes, short-chain fatty acid (SCFA) content in the cecum, and gene expression in the colon were measured to examine the effect of arecoline on relieving constipation. The results showed that arecoline intervention alleviated loperamide-induced constipation, as evidenced by significantly shortened intestinal transit time, increased fecal water content, improved small bowel propulsion, and increased defecation frequency. In addition, arecoline significantly reduced the levels of gastrointestinal regulatory peptides such as somatostatin and vasoactive intestinal peptide in the serum, thereby regulating intestinal peristalsis. Histopathological analysis showed that arecoline ameliorated intestinal injury caused by constipation. Gut microbial analysis indicated that arecoline altered the taxonomic composition and levels of its metabolite SCFAs in the gut microbiota. Furthermore, the colonic transcriptome results indicated that genes expression related to intestinal diseases were significantly down-regulated by arecoline intervention. In conclusion, the results of the correlation analysis propose a possible mechanism of arecoline in alleviating constipation by modulating the gut microbes and their metabolites and regulating the gut genome.

Wuda granule, a traditional Chinese herbal medicine, ameliorates postoperative ileus by anti-inflammatory action

BACKGROUND

Postoperative ileus (POI) is a temporary disturbance in gastrointestinal motility following surgery, and intestinal inflammatory response plays a critical role in the pathogenesis of POI. Wuda granule (WDG), a gastrointestinal prokinetic Chinese herbal medicine, is prescribed to promote recovery of gastrointestinal function after abdominal surgery. However, it has remained unclear whether WDG shows anti-inflammatory effects in POI. In the present study, we investigated the effects of WDG in a rat POI model and attempted to clarify the detailed mechanisms of action.

METHOD

Experimental POI was induced in adult male SD rats by intestinal manipulation (IM). WDG were orally administered after surgery at the same points (6 h, 12 h, 18 h, 24 h). Histological changes of mesenterium, levels of cytokines, and CD68 and iNOS expression were determined in rats treated or not with WDG. We also investigated the transcriptome profile of rats treated with WDG in a POI model.

RESULTS

Experimental POI in rats was characterized by a marked intestinal and systemic inflammatory response. WDG significantly inhibited the infiltration of neutrophils and macrophages, reduced the levels of IL-6, and CRP, and inhibited protein expressions of CD68 and iNOS in mesentery. Comparison analysis showed that there are 1432 differentially expressed genes (DEGs) between the POI and CON sample, whereas 331 DEGs between the WDG -treated sample and the POI group. And 16 DEGs were shared by the POI vs CON and WDG vs POI groups, among which 6 hub genes associated with immune system processes were identified and verified.

CONCLUSIONS

WDG treatment ameliorates the impaired gastrointestinal motility in the rat model of POI through inhibiting the inflammatory response of mesentery.

Effects of Chinese herbal medicine Xiangbin prescription on gastrointestinal motility

AIM

To investigate the effects of Xiangbin prescription (XBP), a Chinese herbal concoction, on gastrointestinal motility.

METHODS

Forty healthy volunteers were recruited for this randomized controlled trial of XBP. Antroduodenojejunal manometry was used to monitor gastrointestinal motility in these subjects. After the subjects had fasted for at least 12 h, XBP (n = 30) or placebo (n = 10) was orally administrated and gastrointestinal motility was recorded for 4 h. Plasma motilin and ghrelin were measured by enzyme-linked immunosorbent assay.

RESULTS

Oral administration of XBP significantly increased the amplitude of duodenal contractions [19.5 (13.0-26.7) vs 16.9 (12.3-23.9), P < 0.05], jejunal contractions [18.3 (15.3-25.0) vs 15.4 (11.7-23.9), P < 0.01], and the motility index of duodenal contractions [522.0 (146.0-139.0) vs 281.0 (76.5-1006.0), P < 0.01] in phase II of the migratory motor complex (MMC), which subsequently initiated the MMC cycle [74.0 (30.0-118.0) vs 116.5 (24.0-219.0), P < 0.05], shortened the duration of phase I of the MMC [42.0 (0.0-90.0) vs 111.5 (42.0-171.0), P < 0.01], and lengthened the duration of phase II of the MMC [120 (21-240) vs 58 (16-170), P < 0.01] compared to the duration before XBP administration. There were significant differences in the amplitude of jejunal contractions [19.8 (14.0-30.0) vs 18.0 (13.0-28.5), P < 0.05], the motility index of duodenal contractions [236.0 (115.0-306.0) vs 195.0 (109.0-310.0), P < 0.05)], and jejunal contractions [214.0 (95.0-403.0) vs 178.0 (55.0-304.0), P < 0.01] in phase III of the MMC. Oral administration of XBP greatly increased plasma motilin (57.69 ± 9.03 vs 49.38 ± 8.63, P < 0.01) and ghrelin (279.20 ± 104.31 vs 238.73 ± 115.59, P < 0.01) concentrations compared to concentrations after oral administration of the placebo.

CONCLUSION

XBP can stimulate duodenal and jejunal motility and increase the concentrations of plasma motilin and ghrelin. The clinical applicability of XBP in treating GDIM deserves investigation.

Areca catechu L. (Arecaceae): a review of its traditional uses, botany, phytochemistry, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Areca catechu L. (Arecaceae), widely distributed in South and Southeast Asia, is a popular traditional herbal medicine that can be chewed for the purpose of dispersing accumulated fluid in the abdominal cavity and killing worms. The present paper aims to provide an up-to-date review on the traditional uses and advances in the botany, phytochemistry, pharmacology and toxicology of this plant. Furthermore, the possible trends and a perspective for future research of this plant are also discussed.

MATERIALS AND METHODS

A literature search was performed on A. catechu based on classic books of herbal medicine, PhD. and MSc. dissertations, government reports, the state and local drug standards, scientific databases including Pubmed, SciFinder, Scopus, the Web of Science, Google Scholar, and others. Various types of information regarding this plant are discussed in corresponding parts of this paper. In addition, perspectives for possible future studies of A. catechu are discussed.

RESULTS

The seeds of A. catechu (areca nut) have been widely used in clinical practice in China, India and other South and Southeast Asian Countries. Currently, over 59 compounds have been isolated and identified from A. catechu, including alkaloids, tannins, flavones, triterpenes, steroids, and fatty acids. The extracts and compounds isolated from A. catechu have many pharmacological activities. These include antiparasitic effects, anti-depressive effects, anti-fatigue effects, antioxidant effects, antibacterial and antifungal effects, antihypertensive effects, anti-inflammatory and analgesic effects, anti-allergic effects, the promotion of digestive functions, suppression of platelet aggregation, regulatory effects on blood glucose and lipids, etc. Although arecoline is the primary active constituent of A. catechu, it is also the primary toxic compound. The main toxicities of arecoline are the promotion of oral submucosal fibrosis (OSF) and cytotoxic effects on normal human cells, which involve inducing apoptosis.

CONCLUSION

As an important herbal medicine, A. catechu has potential for the treatment of many diseases, especially parasitic diseases, digestive function disorders, and depression. Many traditional uses of A. catechu have now been validated by current investigations. However, further research should be undertaken to investigate the clinical effects, toxic constituents, target organs, and pharmacokinetics and to establish criteria for quality control for A. catechu-derived medications. In addition, it will be interesting to investigate the active macromolecular compounds and active constituents other than alkaloids in both raw and processed products of A. catechu.

Simo Decoction Stimulates Contractions of Antral Longitudinal Smooth Muscle via Multitudinous Mechanisms

The aim of the study was to investigate Simo decoction–induced contractions of antral smooth muscles of rats and its mechanisms. The contractile responses of longitudinal strips to consecutive concentrations of Simo decoction were characterized by atropine, gallamine, 4-diphenylacetoxy-N-methylpiperidine methiodide, and adrenaline, hexamethonium, L-arginine, and nifedipine and compared with Krebs solution (control) and acetylcholine-induced contractions. Simo decoction dose-dependently increased contractions of antral strips ( P = .000 vs control); its maximal effect was higher than acetylcholine (10−3 mol L−1; P < .05); Simo decoction–induced contractions were completely inhibited by atropine, 4-diphenylacetoxy-N-methylpiperidine methiodide, or 4-diphenylacetoxy-N-methylpiperidine methiodide + gallamine ( P = .000 for all) but were partly suppressed by gallamine, adrenaline, hexamethonium, L-arginine, and nifedipine ( P = .000 for all). Simo decoction promotes the contractions of antral strips mainly through activation of muscarinic M3 receptor, while partly through activation of M2 receptor, Ca2+ channel, nicotinic receptor, and inhibition of adrenergic receptor as well as release of nitric oxide.

Arecoline excites the contraction of distal colonic smooth muscle strips in rats via the M3 receptor – extracellular Ca2+ influx – Ca2+ store release pathway

Areca is a Chinese herbal medicine that is widely used for constipation. However the mechanisms of its action are not clear. We investigated the effects of arecoline, the most active component of areca, on the motility of rat distal colonic smooth muscle strips. In longitudinal muscle of distal colon (LMDC) and circular muscle of distal colon (CMDC), arecoline increased the contraction in a dose-dependent manner. Tetrodotoxin (TTX) did not inhibit the effects of arecoline. The contractile response to arecoline was completely antagonized by atropine. 4-Diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) strongly depressed the response to arecoline, but gallamine and methoctramine did not. Nifedipine, 2-aminoethoxydiphenyl borate (2-APB), and Ca2+-free Krebs solution with EGTA partly inhibited the effects of arecoline. The sum of Ca2+-free Krebs solution, EGTA, and 2-APB completely inhibited the effects of arecoline. The results show that arecoline stimulates distal colonic contraction in rats via the muscarinic (M3) receptor – extracellular Ca2+ influx – Ca2+ store release pathway. It is likely that the action of areca in relieving constipation is due to its stimulation of muscle contraction.

Effects of neurotrophins on gastrointestinal myoelectric activities of rats

AIM: To observe the effects of mouse nerve growth factor (NGF), rat recombinant brain derived neurotrophic factor (rm-BDNF) and recombinant human neurotrophin-3 (rh-NT-3) on the gastrointestinal motility and the migrating myoelectric complex (MMC) in rat.

METHODS: A randomized, double-blinded, placebo-controlled experiment was performed. 5-7 days after we chronically implanted four or five bipolar silver electrodes on the stomach, duodenum, jejunum and colon, 21 experimental rats were coded and divided into 3 groups and injected NGF, rm-BDNF, rh-NT-3 or placebo respectively via tail vein at a dose of 20 μg·kg^{- 1}. The gastrointestinal myoelectrical activity was recorded 2 hours before and after the test substance infusions in these consciously fasting rats.

RESULTS: The neurotrophins-induced pattern of activity was characterized by enhanced spiking activity of different amplitudes at all recording sites, especially in the colon. In the gastric antrum and intestine, only rh-NT-3 had increased effects on the demographic characteristics of electrical activities (P < 0.05), but did not affect the intervals of MMCs. In the colon, all the three kinds of neurotrophins could significantly increase the frequency, amplitude and duration levels of spike bursts, and also rh-NT-3 could prolong the intervals of MMC in the transverse colon (25 ± 11 min vs 19 ± 6 min, P < 0.05). In the distal colon rh-NT-3 could evoke phase III-like activity and disrupt the MMC pattern, which was replaced by a continuously long spike bursts (LSB) and irregular spike activity (ISA) for 48 ± 6 min.

CONCLUSION: Exogenous neurotrophic factors can stimulate gut myoelectric activities in rats.

Action of progesterone on contractile activity of isolated gastric strips in rats

AIM: To study the effect of progesterone on contractile activity of isolated gastric strips in rats.

METHODS: Wistar rats were sacrificed to remove whole stomach. Then, the stomach was opened and the mucosal layer was removed. Parellel to either the circular or the longitudial fibers, muscle strips were cut from fundus, body, antrum and pylorus. Each muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution. Then the motility of gastric strips in tissue chambers was simultaneously recorded. The preparations were subjected to 1 g load tension and washed with 5 ml Krebs solution every 20 min. After 1 h equilibration, progesterone or antagonists were added in the tissue chamber separately. The antagonists were added 3 min before using progesterone (50 µmol·L^-1).

RESULTS: Progesterone decreased the resting tension of fundus and body longitudinal muscle (LM) (P < 0.05). It inhibited the mean contractile amplitude of body and antrum LM and circular muscle (CM), and the motility index of pyloric CM (P < 0.05). The inhibition of progesterone on the mean contractile amplitude could be partially blocked by phentolamine in LM of the stomach body (the mean contractile amplitude of body LM decreased from -7.5 ± 5.5 to -5.2 ± 4.5 P < 0.01), and by phentolamine or indomethacin in CM of body (The inhibition of progesterone on the mean contractile amplitude of body CM decreased from -5.6 ± 3.0 to -3.6 ± 2.7 by phentolamine and from -5.6 ± 3.0 to -3.5 ± 2.5 by indomethacin, P < 0.01). Hexamethonium, propranolol and L-NNA (inhibitor of NO synthetase) didn’t affect the action of progesterone (P > 0.05).

CONCLUSION: The study suggested that progesterone can inhibit the contractile activity of isolated gastric strips in rats and the mechanism seems to be a direct one except that the action on gastric body is mediated through prostaglandin and adrenergic α receptor partly.

Effect of pinaverium bromide on stress-induced colonic smooth muscle contractility disorder in rats

AIM

To investigate the effect of pinaverium bromide, a L-type calcium channel blocker with selectivity for the gastrointestinal tract on contractile activity of colonic circular smooth muscle in normal or cold-restraint stressed rats and its possible mechanism.

METHODS

Cold-restraint stress was conducted on rats to increase fecal pellets output. Each isolated colonic circular muscle strip was suspended in a tissue chamber containing warm oxygenated Tyrode-Ringer solution. The contractile response to ACh or KCl was measured isometrically on ink-writing recorder. Incubated muscle in different concentrations of pinaverium and the effects of pinaverium were investigated on ACh or KCl-induced contraction. Colon smooth muscle cells were cultured from rats and (Ca(2+))(i) was measured in cell suspension using the Ca(2+) fluorescent dye fura-2/AM.

RESULTS

During stress, rats fecal pellet output increased 61 % (P<0.01). Stimulated with ACh or KCl, the muscle contractility was higher in stress than that in control. Pinaverium inhibited the increment of (Ca(2+))(i) and the muscle contraction in response to ACh or KCl in a dose dependent manner. A significant inhibition of pinaverium to ACh or KCl induced (Ca(2+))(i) increment was observed at 10(-6) mol/L. The IC(50) values for inhibition of ACh induced contraction for the stress and control group were 1.66X10(-6) mol/L and 0.91X10(-6) mol/L, respectively. The IC(50) values for inhibition of KCl induced contraction for the stress and control group were 8.13X10(-7) mol/L and 3.80X10(-7) mol/L, respectively.

CONCLUSION

Increase in (Ca(2+))(i) of smooth muscle cells is directly related to the generation of contraction force in colon. L-type Ca(2+) channels represent the main route of Ca(2+) entry. Pinaverium inhibits the calcium influx through L-type channels; decreases the contractile response to many kinds of agonists and regulates the stress-induced colon hypermotility.

Effect of oxytocin on contraction of rabbit proximal colon in vitro

AIM: To investigate the effects of oxytocin (OT) on isolated rabbit proximal colon and its mechanism.

METHODS: Both longitudinal muscle (LM) and circular muscle (CM) were suspended in a tissue chamber containing 5 mL Krebs solution (37 °C), bubbled continuously with 950 mL·L^-1 O2 and 50 mL·L^-1 CO2. Isometric spontaneous contractile responses to oxytocin or other drugs were recorded in circular and longitudinal muscle strips.

RESULTS: OT (0.1 U·L^-1) failed to elicit significant effects on the contractile activity of proximal colonic smooth muscle strips (P > 0.05). OT (1 to 10 U·L^-1) decreased the mean contractile amplitude and the contractile frequency of CM and LM. Hexamethonium (10 μmol·L^-1) partly blocked the inhibition of oxytocin (1 U·L^-1) on the contractile frenquency of CM. N^ω-nitro-L-arginine-methylester (L-NAME, 1 μmol·L^-1), progesterone (32 μmol·L^-1) and estrogen (2.6 μmol·L^-1) had no effects on OT-induced responses.

CONCLUSION: OT inhibits the motility of proximal colon in rabbits. The action is partly relevant with N receptor, but irrelevant with that of NO, progesterone or estrogen.