Gastroprotective activity of violacein isolated from Chromobacterium violaceum on indomethacin-induced gastric lesions in rats: investigation of potential mechanisms of action.
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ABSTRACT:
SUBMITTER: Antonisamy P
PROVIDER: S-EPMC4138890 | biostudies-other | 2014
REPOSITORIES: biostudies-other
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Project description: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. Parallel to either the circular or the longitudinal 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 micromol/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 alpha receptor partly.
| S-EPMC4611448 | biostudies-literature
Project description:Peperomia pellucida is a plant used in traditional medicine to treat gastric ulcers. Although this gastroprotective activity was reported, the active compounds have not been identified. Therefore, the aim herein was to identify the most active compound in the gastroprotective activity of P. pellucida using an ethanol-induced gastric ulcer experimental rat model. A gastroprotective effect was observed when the hexane and dichloromethane extracts were tested, with the higher effect being obtained with the dichloromethane extract (82.3 ± 5.6%) at 100 mg/kg. Dillapiole was identified as the most active compound in this extract. Although there have been previous reports on dillapiole, this is the first on its gastroprotective activity. Rats treated with this compound at 3, 10, 30 and 100 mg/kg showed 23.1, 56.1, 73.2 and 85.5% gastroprotection, respectively. The effect elicited by dillapiole at 100 mg/kg was not attenuated by pretreatment with indomethacin (10 mg/kg, s.c.), a prostaglandin synthesis blocker, NG-nitro-l-arginine methyl ester (70 mg/kg, i.p.), a nitric oxide (NO) synthase inhibitor, or N-ethylmaleimide (10 mg/kg, s.c.), a blocker of sulfhydryl groups. This suggests that the gastroprotective mechanism of action of dillapiole does not involve prostaglandins, NO or sulfhydryl groups.
| S-EPMC6269875 | biostudies-literature
Project description:This study aimed to apply transcriptomics to determine how Molor-Dabos-4 (MD-4) protects healthy rats against indomethacin (IND)-induced gastric ulcers and to identify the mechanism behind this protective effect. Rats were pretreated with MD-4 (0.3, 1.5, or 3 g/kg per day) for 21 days before inducing gastric ulcers by oral administration with indomethacin (30 mg/kg). Unulcerated and untreated healthy rats were used as controls. Effects of the treatment were assessed based on the ulcer index, histological and pathological examinations, and indicators of inflammation, which were determined by enzyme-linked immunosorbent assay. Transcriptomic analysis was performed for identifying potential pharmacological mechanisms. Eventually, after identifying potential target genes, the latter were validated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). After pretreatment with MD-4, gastric ulcers, along with other histopathological features, were reduced. MD-4 significantly (p < 0.05) increased the superoxide dismutase (SOD) levels in ulcers and reduced pepsin, TNF-α, and IL-6 levels. RNA-seq analysis identified a number of target genes on which MD-4 could potentially act. Many of these genes were involved in pathways that were linked to anti-inflammatory and antioxidant responses, and other protective mechanisms for the gastric mucosa. qRT-PCR showed that altered expression of the selected genes, such as Srm, Ryr-1, Eno3, Prkag3, and Eef1a2, was consistent with the transcriptome results. MD-4 exerts protective effects against IND-induced gastric ulcers by reducing inflammatory cytokines and pepsin and increasing the expression of SOD levels. Downregulation of Srm, Ryr-1, Eno3, Prkag3, and Eef1a2 genes involved in regulating arginine and proline metabolism, calcium signaling pathway, HIF-1 signaling pathway, oxytocin signaling pathway, and legionellosis are possibly involved in MD-4-mediated protection against gastric ulcers.
| S-EPMC9602025 | biostudies-literature
Project description:Fatty-acid amide hydrolase (FAAH) catalyzes the intracellular hydrolysis of the endocannabinoid anandamide and other bioactive lipid amides. In the present study, we conducted a comparative characterization of the effects of the newly identified brain-impermeant FAAH inhibitor, URB937 ([3-(3-carbamoylphenyl)-4-hydroxy-phenyl] N-cyclohexylcarbamate), in various rodent models of acute and persistent pain. When administered by the oral route in mice, URB937 was highly active (median effective dose, ED(50), to inhibit liver FAAH activity: 0.3mgkg(-1)) and had a bioavailability of 5.3%. The antinociceptive effects of oral URB937 were investigated in mouse models of acute inflammation (carrageenan), peripheral nerve injury (chronic sciatic nerve ligation) and arthritis (complete Freund's adjuvant). In all models, URB937 was as effective or more effective than standard analgesic and anti-inflammatory drugs (indomethacin, gabapentin, dexamethasone) and reversed pain-related responses (mechanical hyperalgesia, thermal hyperalgesia, and mechanical allodynia) in a dose-dependent manner. ED(50) values ranged from 0.2 to 10mgkg(-1), depending on model and readout. Importantly, URB937 was significantly more effective than two global FAAH inhibitors, URB597 and PF-04457845, in the complete Freund's adjuvant model. The effects of a combination of URB937 with the non-steroidal anti-inflammatory agent, indomethacin, were examined in the carrageenan and chronic sciatic nerve ligation models. Isobolographic analyses showed that the two compounds interacted synergistically to attenuate pain-related behaviors. Furthermore, URB937 reduced the number and severity of gastric lesions produced by indomethacin, while exerting no ulcerogenic effect when administered alone. The results indicate that the peripheral FAAH inhibitor URB937 is more effective than globally active FAAH inhibitors at inhibiting inflammatory pain. Our findings further suggest that FAAH and cyclooxygenase inhibitors interact functionally in peripheral tissues, to either enhance or hinder each other's actions.
| S-EPMC3738192 | biostudies-literature
Project description:BackgroundMedications to prevent the development of NSAID-induced gastric ulcers have a large range of unpleasant side effects. Recent efforts have been focused on determining safer alternative nontoxic and natural forms of anti-ulcer treatments.MethodsTwenty-four male rats were divided into 4 groups: 1: control group that received no treatment; 2: the ndomethacin-treated group that received 20 mg/kg of indomethacin for 2 days to induce the development of gastric ulcers; 3: quercetin-treated group that in addition to the indomethacin treatment, received 50 mg/kg of quercetin 6 hours after and then daily for 14 days and; 4: the melatonin-treated group which received 20 mg/kg of melatonin 6 hours after each indomethacin treatment and then daily for 14 days. All drugs were administered orally. The following parameters were assessed in each group: mean ulcer index of gastric tissue, gastric acid volume and pH, oxidative stress markers: malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH), inflammatory markers: PGE-2, TNF-α, and IL-10, nitric oxide (NO) levels and the relative gene expression of BAX, BCL-2 and COX-2 by real time PCR.ResultsOur findings revealed that the indomethacin-treated group had a significantly increased (p< 0.05) ulcer index, gastric acid volume, and elevated levels of stress, inflammatory, and apoptotic markers compared to controls. In the groups that received quercetin or melatonin, these factors were all significantly decreased (p< 0.05). Between quercetin and melatonin, there was no significant difference in their gastroprotective effect.ConclusionBoth quercetin and melatonin had protective antioxidant, anti-inflammatory and antiapoptotic activity against indomethacin-induced gastric ulcers.
| S-EPMC7816780 | biostudies-literature
Project description:To investigates the mucoprotective effect of genistein on gastric injury in rats with indomethacin (IMN)-induced gastropathy.Male Sprague-Dawley rats were randomly divided into three groups. Group 1 (control; n = 6) was given distilled water (DW). Group 2 (IMN; n = 6) was given indomethacin (IMN) 150 mg/kg dissolved in 5% sodium bicarbonate (NaHCO3-) 1 mL/rat via intragastric tube at time 0 and 4 h. Group 3 (genistein; n = 6) was given genistein 100 mg/kg dissolved in 0.1% dimethyl sulfoxide (DMSO) plus IMN 150 mg/kg at time described as group 2. Four hours after the second dose, the stomach was removed to examine iNOS western blot expression, malondialdehyde (MDA), and histopathologic examination. Serum was collected to determine TNF-alpha and prostaglandin E2 (PGE2) levels using ELISA technique.Tissue MDA and serum TNF-alpha were significantly increased in the IMN group, as compared to the control group (9.70 ± 0.40 vs. 1.56 ± 0.14 nmol/mg protein, P = 0.000; 210.28 ± 0.98 vs. 126.4 ± 0.13 pg/mL, P = 0.000, respectively) and decreased in the genistein group when compared to the IMN group (2.87 ± 0.37 vs. 9.70 ± 0.40 nmol/mg protein, P = 0.000; 156.59 ± 0.10 vs. 210.28 ± 0.98 pg/mL, P = 0.000, respectively). Serum PGE2 level in IMN group was decreased significantly compared with control group (152.83 ± 0.10 vs. 303.33 ± 2.16 pg/mL, P = 0.000) and increased in the genistein group compared to the IMN group (247.65 ± 0.01 vs. 152.83 ± 0.10 pg/mL, P = 0.000). Expression of tissue iNOS was increased in the IMN group and improved in genistein groups. Most of the rats in the IMN group developed moderate to severe gastric erosion and ulcers. Gastric erosions and neutrophil infiltration score were significantly decreased in the genistein group.Genistein attenuated IMN-induced gastropathy in rats by reducing inflammation, decreasing oxidative stress, restoring mucoprotective function, and improving gastric histopathology.This is an experimental study of the effect of NSAIDs in gastropathy. This study demonstrated the efficacy of genistein in treatment of NSAIDs-induced gastropathy. Genistein efficacy is reflected in the attenuation of histological alterations, with improvement in key biological parameters involved in the pathogenesis of NSAIDs gastropathy. Abbreviations used: NSAIDs: Non-steroidal anti-inflammatory drugs; IMN: Indomethacin; COX: Cyclooxygenase; TNF: Tumor necrosis factor; ICAM: Intercellular adhesion molecule; iNOS: Inducible nitric oxide synthase; MDA: Malondialdehyde; CINC: Cytokine-induced neutrophil chemoattractant.
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Project description:Peptic ulcer disease is an injury of the alimentary tract that leads to a mucosal defect reaching the submucosa. This study aimed to formulate and optimize omega-3 oil as a self-nanoemulsifying drug delivery system (SNEDDS) to achieve oil dispersion in the nano-range in the stomach to augment omega-3 oil gastric ulcer protection efficacy. Three SNEDDS components were selected as the design factors: the concentrations of the oil omega-3 (X1, 10-30%), the surfactant tween 20 and Kolliphor mixture (X2, 20-40%), and the cosurfactant transcutol (X3, 40-60%). The mixture experimental design proposed twenty-three formulations with varying omega-3 SNEDDS formulation component percentages. The optimized omega-3 SNEDDS formula was investigated for gastric ulcer protective effects by evaluating the ulcer index and by the determination of gastric mucosa oxidative stress parameters. Results revealed that optimized omega-3-SNEDDS achieved significant improvement in the gastric ulcer index in comparison with pure omega-3 oil. Histopathological findings confirmed the protective effect of the formulated optimized omega-3 SNEDDS in comparison with omega-3 oil. These findings suggest that formulation of omega-3 in the form of a SNEDDS would be more effective in gastric ulcer protection than the administration of omega-3 as a crude oil.
| S-EPMC7076357 | biostudies-literature
Project description:We investigated the effects of enteral nutrition formula on non-steroidal anti-inflammatory drug (NSAID)-induced gastric lesions in mice. Male ICR mice aged 7-9 weeks old were fasted, then orally given either purified water, Mermed® One, or 2-fold diluted Terumeal® 2.0α as enteral nutrition (25 or 50 mL/kg each). Indomethacin (IND) was orally administered at 20 mg/kg after 30 min, and the stomach was removed 6 h later and fixed in formalin. The number and area of lesions in the stomachs of the mice given enteral nutrition showed a significant, dose-dependent decrease compared to the purified water-treated group, and no significant difference was seen between the two enteral nutrition-treated groups. Comparable time courses of plasma IND concentrations suggest that enteral nutrition does not inhibit gastrointestinal absorption of IND. Our findings indicate that administering enteral nutrition could inhibit the onset of NSAID-induced gastric ulcers.
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Project description:Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and ventral tegmental area) on a variety of depressive-like behaviors using rat models. In the naive animal study, we found that HFS of the Cg, vmPFC, NAc core and LHb reduced anxiety levels and increased motivation for food. In the chronic unpredictable stress model, there was a robust depressive-like behavioral phenotype. Moreover, vmPFC HFS, in a comparison of all stimulated targets, produced the most profound antidepressant effects with enhanced hedonia, reduced anxiety and decreased forced-swim immobility. In the following set of electrophysiological and histochemical experiments designed to unravel some of the underlying mechanisms, we found that vmPFC HFS evoked a specific modulation of the serotonergic neurons in the dorsal raphe nucleus (DRN), which have long been linked to mood. Finally, using a neuronal mapping approach by means of c-Fos expression, we found that vmPFC HFS modulated a brain circuit linked to the DRN and known to be involved in affect. In conclusion, HFS of the vmPFC produced the most potent antidepressant effects in naive rats and rats subjected to stress by mechanisms also including the DRN.
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Project description:Chronic diseases such as cancer, diabetes, neurodegenerative and cardiovascular diseases are characterized by an enhanced state of oxidative stress, which may result from the overproduction of reactive species and/or a decrease in antioxidant defenses. The search for new chemical entities with antioxidant profile is still thus an emerging field on ongoing interest. Due to the lack of reviews concerning the antioxidant activity of lichen-derived natural compounds, we performed a review of the antioxidant potential and mechanisms of action of natural compounds isolated from lichens. The search terms "lichens", "antioxidants" and "antioxidant response elements" were used to retrieve articles in LILACS, PubMed and Web of Science published until February 2014. From a total of 319 articles surveyed, 32 met the established inclusion and exclusion criteria. It was observed that the most common isolated compound studied was usnic acid, cited in 14 out of the 32 articles. The most often described antioxidant assays for the study of in vitro antioxidant activity were mainly DPPH, LPO and SOD. The most suggested mechanisms of action were scavenging of reactive species, enzymatic activation and inhibition of iNOS. Thus, compounds isolated from lichens are possible candidates for the management of oxidative stress, and may be useful in the treatment of chronic diseases.
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