Protective effect of amtolmetin guacyl versus placebo diclofenac and misoprostol in healthy volunteers evaluated as gastric electrical activity in alcohol-induced stomach damage

Agomelatine prevents indomethacin-induced gastric ulcer in rats

BACKGROUND

Gastric ulcer is a very common gastrointestinal disease that may be dangerous and even may lead to death. The current study was conducted to detect the prophylactic effects of agomelatine on indomethacin-induced gastric ulcer.

METHODS

In this study, a total of 5 groups were created as the sham, ulcer, omeprazole, agomelatine 1 mg/kg and agomelatine 5 mg/kg groups. The effects of agomelatine on indomethacin-induced gastric injury were investigated. Total antioxidant and oxidant levels; the oxidant parameters like oxidative stress index and the inflammation markers such as tumor necrosis factor-α, interleukin-1β, interleukin-6 and interleukin-10 levels in stomach tissue were determined by ELISA. In addition, the gastric mucosal injury occurred in stomach wall was examined with histopathological methods.

RESULTS

While the levels of the inflammatory markers, total oxidant status and oxidative stress index increased at an obvious level especially in the indomethacin group, the total antioxidant status levels decreased. It was observed that these parameters were improved at a significant level in agomelatine 1 mg/kg and agomelatine 5 mg/kg groups when compared to ulcer group; and the results were similar to omeprazole group. It was also observed that our histopathological findings were consistent with all our other results.

CONCLUSIONS

The results of this study showed that agomelatine usage in indomethacin-induced gastric ulcer model provides beneficial results.

Amelioration of ethanol induced apoptotic DNA damage and ulcerative injuries in the mice gastric tissues by starch oral administration

Nowadays, gastric ulcers have become very common gastrointestinal disorders and numerous natural plant extracts exert promising anti-ulcerative effects. Therefore, this study was designed to evaluate the possible protective effect of dietary starch against ethanol induced gastric ulcers in mice. Post-administration of dietary starch for three consecutive days caused remarkable ameliorations in hemorrhagic lesions in gastric mucus and significant suppression in % incidence of ulceration, ulcer index and ulcer score induced by ethanol single administration. Indeed, deep ulceration, necrosis, disruption and degeneration in large areas of mucosa layer together with dense inflammatory cells infiltration and edema in sub-mucosal layer induced by ethanol administration were attenuated by starch post-administration and normalized the tissue architecture of the stomach. This potential protective effect could be attributed to the potent anti-oxidative capacity of starch that causes scavenger of the reactive oxygen species and thereby decreasing single and double DNA stranded break inductions and apoptotic DNA damage revealed by returning the p53 and caspase-3 expression levels to the normal level compared to the ethanol treated group. In conclusion, dietary starch has a potent therapeutic effect against ethanol induced gastric ulcer in mice via its free radical scavengers ability. Thus, we recommended further studies on its possible use as antiulcer drugs.

Amtolmetin: A Reappraisal of NSAID with Gastroprotection

Aim. To assess the gastrosparing effect of amtolmetin guacyl (AMG) against other nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with osteo-/rheumatoid arthritis. Methods. A literature search was done in the electronic databases (PubMed, Google Scholar, Embase, and Scopus) with key words “amtolmetin guacyl”, “amtolmetin”, and “arthritis”; filters were applied to obtain publications between 01-Jan-1985 and 01-Oct-2015, which were “clinical trials” in osteo-/rheumatoid arthritis patients and in “English language.” Studies were assessed using the Jadad criteria and trials with score ≥ 3 were included in the analysis to compare the safety and efficacy of AMG against other NSAIDs. Results. Search yielded 19 publications of which 3 were included for analysis. Baseline characteristics of patients were comparable between the AMG group and other NSAIDs (diclofenac, celecoxib, and piroxicam) groups in all trials. Efficacy of AMG was similar to the other NSAIDs compared in the trials. The number of adverse events (AEs) reported was similar between both the groups; however, severe AEs reported were significantly lower in the AMG group. Of note was the significant lower number of duodenal ulcers after treatment in the AMG group. Conclusions. AMG has efficacy similar to other NSAIDs and a safer gastrointestinal AE profile when compared to the other NSAIDs.

Evaluation of protective effects of costunolide and dehydrocostuslactone on ethanol-induced gastric ulcer in mice based on multi-pathway regulation

The aim of the present study was to evaluate the anti-ulcerogenic activity of costunolide (Co) and dehydrocostuslactone (De) on ethanol-induced gastric ulcer in mice and to elucidate the potential mechanisms of the action involved. Mice were pretreated orally with Co (5 or 20 mg/kg), De (5 or 20 mg/kg) and omeprazole (OME, 20 mg/kg) for 7 consecutive days, followed by ulcer induction using absolute ethanol (0.2 mL/20 g body weight). Treatment with Co had a remarkable gastroprotection compared to the ethanol-ulcerated mice that significantly reduced the ulcerative lesion index (ULI) and histopathological damage. Daily intragastric administration of Co exerted a powerful anti-inflammatory activity as evidenced by the suppression of nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, as well as increased interleukin (IL)-10. Also, pretreatment with Co effectively inhibited ethanol-induced malondialdehyde (MDA) overproduction, increased the depleted superoxide dismutase (SOD) and promoted gastric mucosa epithelial cell proliferation by up-regulating proliferating cell nuclear antigen (PCNA) expression. Similarly, De had a protective effect on ethanol-induced ulcer, which was dependent on the inhibition of inflammatory cytokines and MDA generation, but independent of IL-10, SOD and PCNA improvement. Conclusively, the results have clearly demonstrated the anti-ulcerogenic potential of Co and De on ethanol-induced gastric ulcer; nevertheless, the gastroprotective activity of Co was superior to De due to more multi-pathway regulation than De. These findings suggested that Co or De could be a new useful natural gastroprotective tool against gastric ulcer, which provided a scientific basis for the gastroprotection of sesquiterpene lactones.

Protective effect of trillin against ethanol-induced acute gastric lesions in an animal model

The purpose of the present study was to evaluate gastroprotective effect of trillin on mucosal lesions induced by ethanol.

Tiao He Yi Wei Granule, a Traditional Chinese Medicine, against Ethanol-Induced Gastric Ulcer in Mice

Tiao He Yi Wei granule (DHYW), a traditional Chinese medicine, has been used for the treatment of gastric ulcer in clinical setting. The purpose of the present study was to investigate the possible effect of DHYW and explore the underlying mechanism against ethanol-induced gastric ulcer in mice. The model of ethanol-induced gastric ulcer in mice was induced by ethanol (0.2 mL/kg). Administration of DHYW at the doses of 250, 500 mg/kg body weight prior to the ethanol ingestion could effectively protect the stomach from ulceration. The gastric lesions were significantly ameliorated in the DHYW group compared with that in the model group. Treatment with DHYW markedly decreased the levels of interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). In addition, DHYW treatment elevated myeloperoxidase (MPO) level in stomach, increased superoxide dismutase (SOD) activity, and decreased malonaldehyde (MDA) content in serum and stomach compared with those in the model group. DHYW significantly inhibited NF-κB pathway expressions in the gastric mucosa ulcer group. Taken together, DHYW exerted a gastroprotective effect against gastric ulceration and the underlying mechanism might be associated with NF-κB pathway.

Effect and mechanism of evodiamine against ethanol-induced gastric ulcer in mice by suppressing Rho/NF-кB pathway

Evodiamine (EVD), a major alkaloid compound extracted from the dry unripened fruit Evodia fructus (Evodia rutaecarpa Benth., Rutaceae), has various pharmacological effects. The purpose of the present study was to investigate the possible anti-ulcerogenic potential of EVD and explore the underlying mechanism against ethanol-induced gastric ulcer in mice. Administration of EVD at the doses of 20, 40mg/kg body weight prior to the ethanol ingestion could effectively protect the stomach from ulceration. The gastric lesion was significantly ameliorated in the EVD group compared with that in the model group. Pre-treatment with EVD prevented the oxidative damage and decreased the levels of prostaglandin E2 (PGE2) content, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). In addition, EVD pretreatment markedly increased the serum levels of glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), decreased malonaldehyde (MDA) content in serum and activity of myeloperoxidase (MPO) in stomach tissues compared with those in the model group. In the mechanistic study, significant elevation of Rho, Rho-kinase 1 (ROCK1), ROCK2, cytosolic and nucleic NF-κBp65 expressions were observed in the gastric mucosa group, whereas EVD effectively suppressed the protein expressions of Rho, Rho-kinase 1 (ROCK1), ROCK2, cytosolic and nucleic NF-κBp65 in mice. Moreover, EVD showed protective activity on ethanol-induced GES-1 cells, while the therapeutic effects were not due to its cytotoxity. Taken together, these results strongly indicated that EVD exerted a gastro-protective effect against gastric ulceration. The underlying mechanism might be associated with the improvement of antioxidant and anti-inflammatory status through Rho/NF-κB pathway.

Gastroprotective effect of crocin in ethanol-induced gastric injury in rats

The present study investigated the gastroprotective effect of crocin in ethanol-induced gastric injury in rats. Rats were allocated into a normal group, an ulcer group, a crocin-treated group, an ulcer group pretreated with crocin, and an ulcer group pretreated with omeprazole as a reference anti-ulcer drug. Rats were sacrificed 3h after ethanol administration. Prophylactic administration of crocin (50mg/kg/day, i.p.) for 3 consecutive days before the administration of 70% ethanol (10 ml/kg, orally) resulted in significant gastroprotection compared to ethanol-ulcerated rats as manifested by significant reduction in the gastric ulcer index. Crocin pretreatment increased ethanol-lowered levels of gastric juice mucin and mucosal prostaglandin E2 (PGE2) and interleukin-6 (IL-6). Moreover, crocin significantly decreased ethanol-elevated tumor necrosis factor-alpha (TNF-α) level, myeloperoxidase activity and heat shock protein 70 mRNA and protein levels. It also restored ethanol-altered mucosal levels of glutathione, malondialdehyde and superoxide dismutase activity. Furthermore, crocin-pretreatment alleviated ethanol-induced mucosal apoptosis as revealed by significant down-regulation of cytochrome c and caspase-3 mRNA expression, significant decrease in caspase-3 activity and mitigated DNA fragmentation as indicated by significant decrements in comet parameters. The protective efficacy of crocin was further supported by histological assessment. No significant difference was observed between crocin and omeprazole (20mg/kg orally 1h before ethanol administration) regarding their mucin-secretagogue and antioxidant effects, as well as their effects on TNF-α, IL-6 and cytochrome c. On the other hand, omeprazole was superior in enhancing PGE2 level and in alleviating neutrophil infiltration, caspase-3 activation and DNA fragmentation. Conclusively, crocin protects rat gastric mucosa against ethanol-induced injury via anti-inflammatory, anti-oxidative, anti-apoptotic and mucin-secretagogue mechanisms that are probably mediated by enhanced PGE2 release.

Relationship between alcohol consumption and active Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) is a cause of chronic gastritis and maybe responsible for functional dyspepsia in a subset of patients. Many risk factors, such as alcohol consumption and smoking, may contribute to the colonization and infection of H. pylori in humans. However, studies on the relationship between H. pylori infection and drinking or smoking have produced conflicting results.

OBJECTIVE

The aim of this study was to examine whether consumption of alcohol or smoking is associated with active H. pylori infection in functional dyspepsia patients.

METHODS

H. pylori infection was confirmed by CLOtest and histology on at least two biopsies. Active chronic gastritis was diagnosed using the updated Sydney system. In addition to gender and age, information on drinking and smoking habits was collected using a standard questionnaire. Functional dyspepsia was diagnosed according to the Rome II diagnostic criteria.

RESULTS

H. pylori infection was positive in 27.3% of the 139 functional dyspepsia patients. Both age and gender were not significantly associated with H. pylori infection. A multiple logistic model found that alcohol consumption (OR = 9.05, 95% CI: 1.05-77.98) and pathology (active gastritis) (OR = 595.39, 95% CI: 81.43-4353.33) were associated with H. pylori infection. Active gastritis was associated with alcohol consumption (OR = 2.89, 95% CI: 1.03-8.02), smoking (OR = 2.72, 95% CI: 1.22-6.05) and age (OR = 1.03, 95% CI: 1.01-1.06).

CONCLUSIONS

In patients with functional dyspepsia, there is no significant association between active H. pylori infection and smoking. However, alcohol consumption appears to be associated with H. pylori infection.

Capsaicin and gastric ulcers

In recent years, infection of the stomach with the organism Helicobacter Pylori has been found to be the main cause of gastric ulcers, one of the common ailments afflicting humans. Excessive acid secretion in the stomach, reduction in gastric mucosal blood flow, constant intake of non-steroid anti-inflammatory drugs (NSAIDS), ethanol, smoking, stress etc. are also considered responsible for ulcer formation. The prevalent notion among sections of population in this country and perhaps in others is that "red pepper" popularly known as "Chilli," a common spice consumed in excessive amounts leads to "gastric ulcers" in view of its irritant and likely acid secreting nature. Persons with ulcers are advised either to limit or avoid its use. However, investigations carried out in recent years have revealed that chilli or its active principle "capsaicin" is not the cause for ulcer formation but a "benefactor." Capsaicin does not stimulate but inhibits acid secretion, stimulates alkali, mucus secretions and particularly gastric mucosal blood flow which help in prevention and healing of ulcers. Capsaicin acts by stimulating afferent neurons in the stomach and signals for protection against injury causing agents. Epidemiologic surveys in Singapore have shown that gastric ulcers are three times more common in the "Chinese" than among Malaysians and Indians who are in the habit of consuming more chillis. Ulcers are common among people who are in the habit of taking NSAIDS and are infected with the organism "Helicobacter Pylori," responsible for excessive acid secretion and erosion of the mucosal layer. Eradication of the bacteria by antibiotic treatment and avoiding the NSAIDS eliminates ulcers and restores normal acid secretion.

Increased susceptibility of ethanol-treated gastric mucosa to naproxen and its inhibition by DA-9601, an Artemisia asiatica extract

AIM

To examine the effect of DA-9601, a new gastroprotective agent, on the vulnerability of ethanol-treated rat's stomach to naproxen (NAP).

METHODS

Male Sprague-Dawley rats were pretreated with 1 mL of 50% ethanol twice a day for 5 d and then NAP (50 mg/kg) was administered. DA-9601 was administered 1 h before NAP. Four hours after NAP, the rats were killed to examine gross injury index (mm2), histologic change and to determine mucosal levels of malondialdehyde (MDA), prostaglandin E2 (PGE2), glutathione (GSH) and myeloperoxidase (MPO).

RESULTS

Pretreatment of ethanol significantly increased NAP-induced gastric lesions, as well as an increase in MDA and MPO. On the contrary, mucosal PGE2 and GSH contents were decreased dramatically by ethanol pretreatment, which were aggravated by NAP. DA-9601 significantly reduced NAP-induced gastric injury grossly and microscopically, regardless of pretreatment with ethanol. DA-9601 preserved, or rather, increased mucosal PGE2 and GSH in NAP-treated rats (P<0.05), with reduction in mucosal MDA and MPO levels.

CONCLUSION

These results suggest that repeated alcohol consumption renders gastric mucosa more susceptible to NSAIDs though, at least in part, reduction of endogenous cytoprotectants including PGE2 and GSH, and increase in MPO activation, and that DA-9601, a new gastroprotectant, can reduce the increased vulnerability of ethanol consumers to NSAIDs-induced gastric damage via the mechanism in which PGE2 and GSH are involved.

Gastroprotective effect and mechanism of amtolmetin guacyl in mice

AIM: To investigate the gastroprotective effect and mechanism of amtolmetin guacyl (AMG, MED15) in mice.

METHODS: Male and female Kunming strain mice, weighing 18-22 g, were utilized in the experiment. Normal or ethanol-induced gastric mucosal damage models in mice were successfully established to investigate the gastroprotective effect and mechanism of AMG. In the experiment of gastric mucosal damage after repeated treatment with AMG, the mice were randomly divided into 5 groups: normal group, 3 AMG groups receiving (75, 150 and 300 mg/kg), and tolmetin group receiving 90 mg/kg. The mice were randomly divided into 6 groups as follows: normal group, model group, AMG groups with doses of 75, 150 and 300 mg/kg, respectively, and tolmetin group with a dose of 90 mg/kg in ethanol-induced gastric mucosal damage experiment. The severity of gastric mucosal lesions was scored from 0 to 5. Gastric tissue sections were stained with hematoxylin and eosin (HE) and examined under light microscopy. Also gastric tissue sections were stained with uranyl acetate and lead citrate, and examined under electron microscopy. In addition, nitric oxide (NO) and malondialdehyde (MDA) contents, and nitric oxide synthase (NOS) and superoxide dismutase (SOD) activities in the stomach tissue homogenates were measured by biochemical methods.

RESULTS: Repeated treatment with AMG (75, 150 and 300 mg/kg) for 7 d did not induce any appreciable mucosal damage, and the average score was not significantly different from that of normal mice. In contrast, tolmetin (90 mg/kg) produced significant gastric mucosal lesions compared with the normal group (P < 0.01). AMG (75, 150 and 300 mg/kg) significantly reduced the severity of gastric lesions induced by ethanol in a dose-dependent manner as compared with the model group (P < 0.05, AMG 75 and 150 mg/kg vs model; P < 0.01, AMG 300 mg/kg vs model). Light and electron microscopy revealed that AMG (150 and 300 mg/kg) induced minimal changes in the surface epithelium layer, without vascular congestion or leucocyte adherence. AMG (75, 150 and 300 mg/kg) demonstrated dose-dependent gastroprotective effects on mice in our study. AMG (75, 150 and 300 mg/kg) could significantly increase NO content and NOS level in the stomach homogenates of mice compared with the model group (P < 0.05, AMG 75 mg/kg and 150 mg/kg groups vs model group; P < 0.01, AMG 300 mg/kg vs model group) respectively. Moreover, AMG (150 and 300 mg/kg) not only significantly increased SOD activities but also obviously decreased the MDA content in the stomach homogenates of mice.

CONCLUSION: AMG exerts significant gastroprotective actions on mice and the involved mechanisms may be its antioxidative effect and induction of NO production.

Morphological features of rat gastric mucosa after acute and chronic treatment with amtolmetin guacyl: comparison with non-selective and COX-2-selective NSAIDs

BACKGROUND/AIMS

The compound amtolmetin guacyl (AMG) has been characterized in both animal and human studies as a novel non-selective non-steroidal anti-inflammatory drug (NSAID) endowed with lower ulcerogenicity in comparison with traditional NSAIDs due to a unique mechanism of action, namely the increase in endogenous production of gastric nitric oxide.

METHODS

Conscious rats were treated either acutely (4 h) or chronically (3 and 14 days) with intragastric AMG (50 and 150 mg/kg), the non-selective NSAID tolmetin (TOL, 30 and 100 mg/kg) or the COX-2-selective NSAID celecoxib (CXIB, 20 and 60 mg/kg). Macroscopically visible and histologic lesions were evaluated. The ultrastructure of mucosal microvasculature was assessed.

RESULTS

(1) TOL and CXIB caused quantitatively greater endothelial damage and inflammatory cell infiltration than that induced by AMG; (2) AMG and CXIB, unlike TOL, did not cause epithelial damage after acute or chronic treatment, and (3) gastric lesions induced by TOL underwent adaptation during chronic treatment.

CONCLUSION

Endothelial cell damage in the gastric microvasculature is an early event following both non-selective and COX-2-selective inhibitors. The low gastric mucosal toxicity of AMG is confirmed after acute and chronic treatment.

Impact on the bowel of amtolmetin guacyl, a new gastroprotective non-steroidal anti-inflammatory drug

Amtolmetin guacyl (MED15) is a new non-steroidal anti-inflammatory drug (NSAID) which shares anti-inflammatory, analgesic and antipyretic activity with the other drugs of the NSAID family but which shows, unexpectedly, strong gastroprotective activity similar to misoprostol. This effect has been attributed to the presence in its molecule of a vanillic moiety responsible for stimulation of capsaicin receptors present throughout the length of the gastrointestinal tract. MED15 shows antispasmodic activity in the bowel against a number of agonists and compares favourably with reference compounds. In in vivo indomethacin-induced rat ileitis, MED15 heals better than 5-aminosalicylic acid and sulfasalazine, as well as down-regulating intestinal wall myeloperoxidase content. In acetic acid-induced colitis in the rat, levels of malondialdehyde were found to be more markedly reduced with MED15 than with 5-aminosalicylic acid. In contrast with the effect in the stomach, MED15 protective effect in the bowel appears to be unrelated to nitric oxide (NO) production. The MED15 enteroprotective effect is related to stimulation of intestinal capsaicin receptors as demonstrated by the loss of protective effect in the presence of capsazepine, a specific receptor antagonist of capsaicin. In conclusion, following the favourable results obtained in animal models and notwithstanding the pharmacological effects typical of an NSAID, MED15 may rationally be proposed for the treatment of various human colitis conditions and Crohn's disease.

Physiology and pathophysiology of the interstitial cells of Cajal: from bench to bedside. VI. Pathogenesis and therapeutic approaches to human gastric dysrhythmias

This review describes recent advances in our knowledge about the pathogenesis and therapeutic approaches to human gastric dysrhythmias. A number of clinical conditions has been found to be associated with gastric slow-wave rhythm disturbances that may relate to the induction of nausea and vomiting. Human and animal studies indicate that multiple neurohumoral factors are involved in the generation of gastric dysrhythmias. Antral distension and increased intestinal delivery of lipids may cause slow-wave disruption and development of nausea. This may be mediated by cholinergic and serotonergic pathways. Similarly, progesterone and estrogen may also disrupt gastric slow-wave rhythm in susceptible individuals. Prostaglandin overproduction in gastric smooth muscle appears to mediate slow-wave disruption in diabetes and with tobacco smoking. On the other hand, central cholinergic pathways play an important role in the genesis of gastric dysrhythmias associated with motion sickness. This may be mediated by vasopressin released from the pituitary. Although it is difficult to ascribe with certainty a causative role of slow-wave rhythm disturbances in the genesis of nausea and vomiting, the search has begun for novel antiemetic therapies based on their abilities to ablate or prevent gastric dysrhythmia formation. This includes the use of prostaglandin synthesis inhibitors, central muscarinic receptor antagonists, and dopamine receptor antagonists. Finally direct gastric electrical stimulation using a surgically implanted neurostimulator has shown promise in reducing emesis in patients with gastroparesis and gastric dysrhythmias.