MAGL inhibition modulates gastric secretion and motility following NSAID exposure in mice

Hemp seeds attenuate loperamide-induced constipation in mice

Constipation is a common gastrointestinal disease that seriously affects human physical and mental health. Studies have reported that hemp seeds can improve constipation, however the specific mechanism is still unclear. This study investigates that hemp seed (HS) and its water-ethanol extract (HSE) attenuates loperamide-induced constipation in mice. The research results show that: the fecal water content and small intestinal transit rate of mice in the hemp seed group and hemp seed hydroalcoholic extract group were significantly increased compared with MC group, and the first red feces defecation time was significantly shortened; HS and HSE significantly influence serum levels of Gastrin (Gas), motilin (MTL), substance P (SP), and endothelin (ET), potentially mediating their effects on gastrointestinal motility. HS and HSE can improve colon inflammation in constipated mice with H&E staining. Compared with the model of constipation group, the content of short-chain fatty acids in the HS group and HSE group increased significantly. Gut microbiome studies have shown that the structure and abundance of intestinal flora are altered. HS and HSE changed the abundance of Odoribacter, Bacteroide, Lactobacillus and Prevotella. Together, these results suggest that HS have the potential to stimulate the proliferation of beneficial gut microbes and promote intestinal motility, thereby improving gut health and relieving symptoms of constipation.

Efficacy of an oral suspension containing xyloglucan and pea proteins on a murine model of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is the most common foregut disease, affecting about 20% of the adult population. Esophageal epithelial barrier plays a fundamental role in the pathophysiology of GERD; however, pharmacological therapies mainly aim to reduce the acidity of the gastroesophageal environment rather than to protect esophageal tissue integrity. This study aims to evaluate the efficacy of an oral solution containing xyloglucan and pea proteins (XP) in reestablishing gastroesophageal tissue integrity and biochemical markers. To induce GERD, C57BL/6 mice were alternatively overfed and fasted for 56 days and then treated with XP, sodium alginate, omeprazole, or omeprazole+XP twice daily for 7 days. Gastric pain and inflammatory markers were evaluated after 3 and 7 days of treatment. After sacrifice, the esophagi and stomachs were surgically removed for macroscopic and histological examination. Gastric pain was significantly reduced at days 3 and 7 by XP, omeprazole, and omeprazole+XP, while alginates were ineffective at day 3. XP was able to diminish gastric macroscopic damage and demonstrated the same efficacy as omeprazole in reducing esophageal damage. XP significantly reduced histological damage, with an efficacy comparable to that of omeprazole, but superior to alginates. Inflammatory markers were significantly reduced by XP, with superior efficacy compared with alginates at day 7. Interestingly, XP was also able to significantly increase gastric pH. This study demonstrated that XP restored gastric homeostasis, improved esophageal integrity, and decreased inflammation and pain with a similar efficacy to omeprazole and greater than alginates.

Targeting the endocannabinoid system for the treatment of abdominal pain in irritable bowel syndrome

The management of visceral pain in patients with disorders of gut-brain interaction, notably irritable bowel syndrome, presents a considerable clinical challenge, with few available treatment options. Patients are increasingly using cannabis and cannabinoids to control abdominal pain. Cannabis acts on receptors of the endocannabinoid system, an endogenous system of lipid mediators that regulates gastrointestinal function and pain processing pathways in health and disease. The endocannabinoid system represents a logical molecular therapeutic target for the treatment of pain in irritable bowel syndrome. Here, we review the physiological and pathophysiological functions of the endocannabinoid system with a focus on the peripheral and central regulation of gastrointestinal function and visceral nociception. We address the use of cannabinoids in pain management, comparing them to other treatment modalities, including opioids and neuromodulators. Finally, we discuss emerging therapeutic candidates targeting the endocannabinoid system for the treatment of pain in irritable bowel syndrome.

Prevention of loperamide induced constipation in mice by KGM and the mechanisms of different gastrointestinal tract microbiota regulation

Constipation is one of the most prevalent gastrointestinal tract diseases. Konjac glucomannan (KGM) dietotherapy can effectively relieve the clinical symptoms of patients with constipation. However, the causal relationship among KGM, constipation and different gastrointestinal microbiome (i.e., the stomach {St}, small intestine {S}, and large intestine {L}) remains poorly understood. In this study, constipated mice were treated with KGM (75, 150, 300 mg/kg bw). Results showed that KGM treatment improved the general physiological state, fecal character, small intestinal propulsive rate, gastric emptying rate, MTL and AchE activities, ET-1, 5-HT, and NO levels, and SCFA concentrations. KGM in the diets of constipated mice reduced the diversity of St and S microbiota, while increased those in the L. The KGM intervention regulated the microbiota profile, which afterwards was closer to the normal mouse group: confirmation was provided by different changes of bacteria like Lactobacillus, Bifidobacterium and Allobaculum spp et al.

Exploring the fatty acid amide hydrolase and cyclooxygenase inhibitory properties of novel amide derivatives of ibuprofen

Inhibition of fatty acid amide hydrolase (FAAH) reduces the gastrointestinal damage produced by non-steroidal anti-inflammatory agents such as sulindac and indomethacin in experimental animals, suggesting that a dual-action FAAH-cyclooxygenase (COX) inhibitor could have useful therapeutic properties. Here, we have investigated 12 novel amide analogues of ibuprofen as potential dual-action FAAH/COX inhibitors. N-(3-Bromopyridin-2-yl)−2-(4-isobutylphenyl)propanamide (Ibu-AM68) was found to inhibit the hydrolysis of [³H]anandamide by rat brain homogenates by a reversible, mixed-type mechanism of inhibition with a K_i value of 0.26 µM and an α value of 4.9. At a concentration of 10 µM, the compound did not inhibit the cyclooxygenation of arachidonic acid by either ovine COX-1 or human recombinant COX-2. However, this concentration of Ibu-AM68 greatly reduced the ability of the COX-2 to catalyse the cyclooxygenation of the endocannabinoid 2-arachidonoylglycerol. It is concluded that Ibu-AM68 is a dual-acting FAAH/substrate-selective COX inhibitor.

Druggable Targets in Endocannabinoid Signaling

Cannabis and cannabinoid-based extracts have long been utilized for their perceived therapeutic value, and support for the legalization of cannabis for medicinal purposes continues to increase worldwide. Since the discovery of Δ⁹-tetrahydrocannabinol (THC) as the primary psychoactive component of cannabis over 50 years ago, substantial effort has been directed toward detection of endogenous mediators of cannabinoid activity. The discovery of anandamide and 2-arachidonoylglycerol as two endogenous lipid mediators of cannabinoid-like effects (endocannabinoids) has inspired exponential growth in our understanding of this essential pathway, as well as the pathological conditions that result from dysregulated endocannabinoid signaling. This review examines current knowledge of the endocannabinoid system including metabolic enzymes involved in biosynthesis and degradation and their receptors, and evaluates potential druggable targets for therapeutic intervention.

Zona incerta projection neurons and GABAergic and GLP-1 mechanisms in the nucleus accumbens are involved in the control of gastric function and food intake

OBJECTIVE

Our aim was to explore the effect of γ-aminobutyric acid (GABA) signaling in the nucleus accumbens (NAc) on promoting gastric function and food intake through glucagon-like peptide 1 (GLP-1)-sensitive gastric distension (GD) neurons under the regulatory control of the zona incerta (ZI).

METHODS

GABA neuronal projections were traced using retrograde tracing following fluorescence immunohistochemistry. An extracellular electrophysiological recording method was used to observe the firing of neurons in the NAc. HPLC was used to quantify the GABA and glutamate levels in the NAc after electrical stimulation of the ZI. Gastric functions including gastric motility and secretion, as well as food intake, were measured after the administration of different concentrations of GABA in the NAc or electrical stimulation of the ZI.

RESULTS

Some of the GABA-positive neurons arising from the ZI projected to the NAc. Some GABA-A receptor (GABA-AR)-immunoreactive neurons in the NAc were also positive for GLP-1 receptor (GLP-1R) immunoreactivity. The firing of most GLP-1-sensitive GD neurons was decreased by GABA infusion in the NAc. Intra-NAc GABA administration also promoted gastric function and food intake. The responses induced by GABA were partially blocked by the GABA-AR antagonist bicuculline (BIC) and weakened by the GLP-1R antagonist exendin 9-39 (Ex9). Electrical stimulation of the ZI changed the firing patterns of most GLP-1-sensitive GD neurons in the NAc and promoted gastric function and food intake. Furthermore, these excitatory effects induced by electrical stimulation of the ZI were weakened by preadministration of BIC in the NAc.

CONCLUSION

Retrograde tracing and immunohistochemical staining showed a GABAergic pathway from the ZI to the NAc. GABAergic and GLP-1 mechanisms in the NAc are involved in the control of gastric function and food intake. In addition, the interaction (direct or indirect) between the ZI and these NAc mechanisms is involved in the control of gastric function and food intake.

CB1 positive allosteric modulation attenuates Δ9-THC withdrawal and NSAID-induced gastric inflammation

Recently, multiple compounds have been synthesized that target the allosteric binding site(s) of CB1. These CB1 positive allosteric modulators may capture the benefits of cannabinoid receptor activation without unwanted psychoactive effects, such as sedation. For example, ZCZ011 blocks neuropathic pain, absent the catalepsy, sedation, and hypothermia caused by CB1 orthosteric modulators, including Δ9-tetrahydrocannabinol (THC). The primary goal of the present study was to evaluate the potential of ZCZ011 to attenuate somatic signs of cannabinoid withdrawal in mice. Mice were repeatedly administered THC (10 mg/kg, s.c.) or vehicle, and withdrawal was either precipitated using the CB1 antagonist rimonabant (3 mg/kg, i.p.) or elicited spontaneously via THC abstinence. ZCZ011 (≥10 mg/kg, i.p.) significantly attenuated somatic signs of withdrawal, including head twitches and paw tremors, but had no effect on locomotor activity or conditioned place preference. We next tested the antiulcerogenic properties of CB1 positive allosteric modulation. Mice were fasted for 22 h, administered ZCZ011, and gastric hemorrhages were induced with the nonsteroidal anti-inflammatory drug diclofenac sodium (100 mg/kg, p.o.). ZCZ011 alone had no effect on gastric ulceration, but ZCZ011 (≥10 mg/kg) blocked ulcer formation when combined with a subthreshold MAGL inhibitor (JZL184; 1 mg/kg, i.p.). Thus, CB1 positive allosteric modulation is a novel approach to treat cannabinoid dependence and gastric inflammation.