Ulcer healing and mechanism(s) of action involved in the gastroprotective activity of fractions obtained from Syngonanthus arthrotrichus and Syngonanthus bisulcatus

Gastroprotective role of a flavonoid-rich subfraction from Fridericia chica (Bonpl.) L. G. Lohmann: a medicinal plant used in the Amazon region

Fridericia chica is an Amazonian plant used to treat stomach disorders. However, the pharmacological activity of flavonoids in the extract has yet to be investigated. Therefore, we considered that a flavonoid-rich F. chica subfraction (FRS) has gastroprotective functions. For this, before the induction of gastric ulcers with ethanol or piroxicam, the rats received vehicle (water), omeprazole (30 mg/kg), or FRS (30 mg/kg), and the ulcer area was measured macro and microscopically, and the antisecretory action was investigated in pylorus-ligated rats. In addition, the roles of nitric oxide (NO) and nonprotein sulfhydryl compounds (NP-SH) in the gastroprotective effects of FRS were studied. FRS reduced ethanol- and piroxicam-induced ulcerations by 81% and 77%, respectively, as confirmed histologically. Antioxidant effects were observed for FRS through the maintenance of GSH and LPO levels, and the SOD and CAT activity similar to those found in the nonulcerated group. Moreover, FRS avoided the increase in MPO activity and TNF, IL-6, IL-4 and IL-10 levels. Moreover, mucin staining increased in ulcerated rats receiving FRS, and the pharmacological mechanism gastroprotective seems to involve the NO and NP-SH in addition to antisecretory actions. The chemical study by mass spectrometry confirmed the presence of flavonoids in FRS, and molecular docking studies have shown that these compounds interact with cyclooxygenase-1 and NO synthase. Furthermore, there was no indication that FRS had cytotoxic effects. Our results support the popular use of F. chica, and we conclude that the gastroprotection effect promoted by FRS can be attributed to the combined effect of the flavonoids.

Efficacy of pantoprazole plus perforation repair for peptic ulcer and its effect on the stress response

BACKGROUND

Peptic ulcer (PU) is an abnormal phenomenon in which there is rupture of the mucosa of the digestive tract, which not only affects patients' normal life but also causes an economic burden due to its high medical costs.

AIM

To investigate the efficacy of pantoprazole (PPZ) plus perforation repair in patients with PU and its effect on the stress response.

METHODS

The study subjects were 108 PU patients admitted between July 2018 and July 2022, including 58 patients receiving PPZ plus perforation repair [research group (RG)] and 50 patients given simple perforation repair [control group (CG)]. The efficacy, somatostatin (SS) concentration, stress reaction [malondialdehyde (MDA), lipid peroxide (LPO)], inflammatory indices [tumor necrosis factor (TNF)-α, C-reactive protein (CRP), interleukin (IL)-1β], recurrence, and complications (perforation, hemorrhage, and pyloric obstruction) were compared.

RESULTS

The overall response rate was higher in the RG than in the CG. Patients in the RG had markedly elevated SS after treatment, which was higher than that of the CG, while MDA, LPO, TNF-, CRP, and IL-1β were significantly reduced to lower levels than those in the CG. Lower recurrence and complication rates were identified in the RG group.

CONCLUSION

Therefore, PPZ plus perforation repair is conducive to enhancing treatment outcomes in PU patients, reducing oxidative stress injury and excessive inflammatory reactions, and contributing to low recurrence and complication rates.

Gastroprotective action of the ethanol extract of Leonurus sibiricus L. (Lamiaceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus sibiricus L. (Lamiaceae) is a medicinal plant known in Brazil as "rubim" or "erva de macaé". It is used for various purposes, including stomach disorders.

AIM OF THE STUDY

To evaluate the effect of the ethanol extract of the aerial parts of L. sibiricus (EELs) in models of gastric damage in mice.

MATERIAL AND METHODS

The effect of EELs (50, 100 and 300 mg/kg, p.o., 1 h before induction) was tested on acidified ethanol (ACEt)-induced gastric ulcers. Additionally, we tested the effect of EELs (by intraduodenal administration) in the pylorus ligation (PL) model.

RESULTS

Pretreatment with EELs, at 300 mg/kg, but not 50 and 100 mg/kg, reduced the relative area of gastric ulcers induced by ACEt (p < 0.01) and lipoperoxidation (p < 0.001), and increased the sulfhydryl content (p < 0.01) in the stomach in comparison with the vehicle group. Pretreatment with N-ethylmaleimide (a blocker of non-protein sulfhydryl groups, 10 mg/kg, i.p.) or glibenclamide (a K_ATP channel blocker, 10 mg/kg, i.p.) inhibited the gastroprotective response caused by EELs (300 mg/kg; p < 0.001), but there were no alterations due to pretreatments with inhibitors of the synthesis of prostaglandins (indomethacin, 10 mg/kg), nitric oxide (L-NAME, 70 mg/kg) or hydrogen sulfide (DL-propargylglycine, 10 mg/kg). Treatment with EELs (300 mg/kg) reduced mucus production (p < 0.001) and the volume of gastric secretion (p < 0.001) after PL without affecting gastric acidity or pH.

CONCLUSIONS

These results provide evidence that EELs exerts gastroprotective action in mice, with the participation of oxidative stress and mediation of NP-SH, K_ATP channels and mucus production.

Pretreatment of Blumea lacera leaves ameliorate acute ulcer and oxidative stress in ethanol-induced Long-Evan rat: A combined experimental and chemico-biological interaction

Blumea lacera (Burm.f.) DC. is described as a valuable medicinal plant in various popular systems of medicine. The aim of the experiment reports the in vivo antiulcer activity of methanol extract of Blumea lacera (MEBLL) and in silico studies of bioactive constituents of MEBLL. In this study, fasted Long-Evans rat treated with 80 % ethanol (0.5 mL) to induce gastric ulcer, were pretreated orally with MEBLL at different doses (250 and 500 mg/kg, p.o., b.w) and omeprazole (20 mg/kg, p.o.) and distilled water were used as a reference drug and normal control respectively. In silico activity against gastric H+-K+ATPase enzyme was also studied. The findings demonstrated that the treatment with MEBLL attenuated markedly ulcer and protected the integrity of the gastric mucosa by preventing the mucosal ulceration altered biochemical parameters of gastric juice such total carbohydrate, total protein and pepsin activity. Additionally, the experimental groups significantly (p < 0.001) inhibited gastric lesions and malondealdehyde (MDA) levels and upregulated antioxidant enzymes level. Furthermore, nine compounds were documented as bioactive, displayed good binding affinities to against gastric H+-K+ATPase enzyme while these compounds illustrated inhibitory effect. From these studies, it is established MEBLL has ulcer healing property as unveiled by in vivo and in silico studies.

UPLC-qTOF-MS Phytochemical Profile and Antiulcer Potential of Cyperus conglomeratus Rottb. Alcoholic Extract

Cyperus has been commonly used as a multi-use medicinal plant in folk medicine worldwide. The objectives of our study were to determine the different metabolites in the Cyperus conglomeratus Rottb. methanol extract, and to assess its in vivo gastroprotective effect in ethanol-induced gastric ulcer model in rats. Serum levels of galactin-3 and TNF-α were employed as biochemical markers. To pinpoint for active agents, comprehensive metabolites profiling of extract via UPLC-qTOF-MS/MS was employed. A total of 77 chromatographic peaks were detected, of which 70 were annotated. The detected metabolites were categorized into phenolic acids and their derivatives, flavonoids, stilbenes, aurones, quinones, terpenes, and steroids. Rats were divided into six groups; healthy control, ulcer control, standard drug group, and 25, 50, 100 mg/kg of C. conglomeratus treated rats. Pre-treatment with C. conglomeratus alcohol extract significantly reduced galactin-3, and TNF-α in ethanol-induced ulcer model at 25, 50, and 100 mg/kg. Further histopathological and histochemical studies revealed moderate erosion of superficial epithelium, few infiltrated inflammatory cells, and depletion of gastric tissue glycoprotein in the ulcer group. Treatment with the extract protected the gastric epithelial cells in a dose-dependent manner. It could be concluded that C. conglomeratus extract provides significant gastroprotective activity in ethanol-induced gastric ulcer and ought to be included in nutraceuticals in the future for ulcer treatment.

Manilkara hexandra (Roxb.) Dubard Ameliorates Acetic Acid-induced Rat Gastric Ulcer

Manilkara hexandra (Roxb; Family:sapotaceae) is reported to exert preventive effect in several experimental ulcer models. However, there is no report of M. hexandra on gastric ulcer healing property. Thus, the present study was designed to evaluate the gastric ulcer healing activity of methanolic stem bark extract of M. hexandra (MH) and to derive a plausible molecular level of mechanism of action. MH was subjected to several phytochemical screening tests and standardized to quercetin by HPTLC. In the first pharmacological experiment, the standardized MH (50, 100 and 200 mg/kg) was carried out for ulcer healing activity against acetic acid (AA)-induced gastric ulcer in male rats. MH (100 and 200 mg/kg) ameliorated AA-induced rat gastric lesions. Further, MH (100 and 200 mg/kg) attenuated AA-induced changes in the levels of lipid peroxidation (LPO), reduced glutathione (GSH), oxidized glutathione (GSSG) and ratio of GSH/GSSG and activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) enzymes, and level of hame oxygenase-1 (HO-1) in stomach tissue. In the subsequent set of experiment, trigonelline (30 mg/kg; p.o.), a potent Nrf2 antagonist, significantly abrogated the gastric ulcer healing activity of MH (100 mg/kg) in AA challenged animals. Further, trigonelline attenuated the effects of MH (100 mg/kg) on the levels of LPO, GSH, GSSG and ratio of GSH/GSSG and activity of SOD, CAT, GPx and GR enzymes, and level of HO-1 in AA challenged rodents. These observations implicate the fact that MH could be a better therapeutic alternative in the management of gastric ulcer.

Gastroprotective effect of ethyl acetate extract from Avicennia schaueriana Stapf & Leechman and underlying mechanisms

OBJECTIVE

Avicennia schaueriana Stapf is an endemic mangrove species widely used by traditional Brazilian communities as a folk remedy for the treatment of rheumatism, ulcers, and skin wounds. The aim of the present study was to evaluate the gastroprotective potential of the ethyl acetate extract from the leaves of A. schaueriana (As-AcOEt).

METHODS

Ultra-performance liquid chromatography coupled with diode-array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS/MS) was performed to identify chemical constituents of the ethyl acetate extract from the leaves ofA. schaueriana. Total phenols, flavonoids and tannins were determined and antioxidant activity was evaluated using the DPPH and ABTS methods. The acute toxicity of As-AcOEt and gastroprotective activity on HCl/ethanol-induced gastric ulcers were assessed and mechanisms of action involving the role of nitric oxide, sulfhydryl compounds, and prostaglandins were investigated.

RESULTS

Terpenes, flavonoids and tannins were detected in the extract. As-AcOEt exhibited antioxidant activity, with an EC₅₀ of 42.2 ± 4.4 μg/mL (DPPH) and 73.2% inhibition of ABTS radicals. UPLC-DAD-QTOF-MS/MS analysis identified gallic acid, gallic acid derivative, ellagic acid, myricetin pentoside, myricetin deoxyhexose, quercetin pentoside, quercetin deoxyhexose, and other compounds. Gallic acid was isolated in this species for the first time. During the acute toxicity test, no deaths or changes occurred in the variables evaluated. In the ethanol-induced ulcer model, As-AcOEt reduced the ulcerative lesion index, with 50, 100 and 200 mg/kg achieving 83.8, 88.5 and 86.9% inhibition, respectively. MPO levels decreased and the gastric mucosa of the animals treated with the extract was preserved. Pre-treatment with N-omega-nitro-l-arginine methyl ester (L-NAME; NO blocker) or carbenoxolone (CBXN; NP-SH blocker) reversed the gastroprotective effect of As-AcOEt, but this effect was not reversed with the previous administration of indomethacin.

CONCLUSION

The present findings reveal that the extract from the leaves ofA. schaueriana has gastroprotective effects, suggesting the involvement of nitric oxide and nonprotein sulfhydryl compounds, but not prostaglandin. Therefore, the use of A. schaueriana in Brazilian folk medicine for the treatment of gastric disorders has a scientific basis.

Cytoprotective, antioxidant and anti-inflammatory mechanism related to antiulcer activity of Cissampelos sympodialis Eichl. in animal models

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves and roots of Cissampelos sympodialis (Menispermaceae) are used by indian tribes and in folk medicine to treat genitourinary infections, inflammation, asthma and gastrointestinal disorders.

MATERIAL AND METHODS

The standardized ethanolic extract (Cs-EtOHE) and alkaloids total fraction (Cs-TAF) obtained from aerial parts of C. sympodialis were evaluated in several models of acute gastric ulcers. The antisecretory and/or neutralizing mechanisms of the gastric acid secretion, cytoprotective, antioxidant and immunoregulatory mechanisms were also evaluated.

RESULTS

Cs-EtOHE and Cs-TAF presented a reduction in gastric mucosa lesions against ethanol, NSAIDs, hypothermic restraint-stress and gastric juice containment induced ulcer models. This activity is related to alkaloids present in the extract, and involves the participation of sulfhydryl compounds, nitric oxide, K_ATP channels, prostaglandins, decreased levels of IL-1β and TNF-α and increased levels of GSH and IL-10.

CONCLUSION

The data indicate gastroprotective activity, due to the participation of the cytoprotective, antioxidant and immunoregulatory mechanisms.

Critical Evaluation of Animal Models of Gastrointestinal Disorders

Preclinical research remains an important tool for discovery and validation of novel therapeutics for gastrointestinal disorders. While in vitro assays can be used to verify receptor-ligand interactions and test for structural activity of new compounds, only whole-animal studies can demonstrate drug efficacy within the gastrointestinal system. Most major gastrointestinal disorders have been modeled in animals; however the translational relevance of each model is not equal. The purpose of this chapter is to provide a critical evaluation of common animal models that are being used to develop pharmaceuticals for gastrointestinal disorders. For brevity, the models are presented for upper gastrointestinal disorders involving the esophagus, stomach, and small intestine and lower gastrointestinal disorders that focus on the colon. Particular emphasis is used to explain the face and construct validity of each model, and the limitations of each model, including data interpretation, are highlighted. This chapter does not evaluate models that rely on surgical or other non-pharmacological interventions for treatment.

Effects of quinine on gastric ulcer healing in Wistar rats

Background Quinine (QT) is an important anti-malarial drug; however, there is little information about its effects on the gut. Therefore, this study aimed to investigate the effects of a therapeutic dose of QT on the healing of gastric ulcer in rats. Methods Male Wistar rats weighing 150-200 g were divided into three groups: control rats without ulcer (group 1), ulcerated rats treated with 1 mL/kg (p.o.) normal saline (NS) (group 2), and ulcerated rats treated with 10 mg/kg (p.o.) QT (group 3). Ulcers were induced by serosal application of 80 % acetic acid to the stomach of rats anaesthetized with 50 mg/kg thiopentone sodium and treatment was given three times daily. Healing was assessed on days 3, 7 and 10 after ulcer induction by macroscopic measurement of: ulcer area, histology, lipid peroxidation, superoxide dismutase activity and gastric mucus secretion. Results At day 3, there was no significant difference (p>0.05) in ulcer areas between NS- and QT-treated rats. By day 10, however, the percentage area healed in NS treated (59.6±2.35 %) was significantly higher (p<0.05) than in QT rats (49.0±2.20 %) and clearing of inflammatory cells and re-epithelization was greater in NS-treated group. By days 7 and 10, lipid peroxidation was significantly higher in QT animals, when compared with NS-treated rats and controls (p<0.05). Superoxide dismutase activity and mucus secretion were significantly (p<0.05) higher in NS-treated than QT-treated rats. Conclusions QT delayed ulcer healing by prolonging the inflammatory phase of healing, increasing oxidative stress, reducing antioxidant activity and gastric mucus secretion.

Nanocrystalline cerium dioxide efficacy for prophylaxis of erosive and ulcerative lesions in the gastric mucosa of rats induced by stress

In our previous works, the important therapeutic properties of nanocrystalline cerium dioxide such as strong antioxidant ability, prebiotical and antibiotic activity were shown. Such properties were obtained due to stabilization of nanoparticles with precise size 3-7nm. Such modification of nanocrystalline cerium dioxide has contributed to its remarkable efficacy and low toxicity. We have carried out the investigation of toxicity of the nanodrug and revealed that in the condition of the acute toxicity test, LD 50 was 2000mg/kg when it was administered per os. This indicator is approximately 1000 times greater than effective dose of the compound that proved the possibility of its usage for humans. Considering the strong antioxidant properties of this substance, we have performed the investigation of the influence of nanocrystalline cerium dioxide on the erosive-ulcerative lesions in gastric mucosa of rats induced by Selye's restraint stress. It was established that the studied compound significantly reduced the lesions area by 58.3% (p<0.05) induced by Selye's restraint stress. The attenuation of inflammation and decrease of lipid peroxidation in the conditions of gastric lesions and prophylactic administration of nanocrystalline cerium dioxide were shown. That was confirmed by the decrease of pro-inflammatory cytokines content (interleukin (IL) 1β, 12B p40) and raise of anti-inflammatory cytokines content (IL-10 and transforming growth factor β). Measurement of lipid peroxidation products has proved the antioxidant properties of nanocrystalline cerium dioxide as it decreased the content of conjugated dienes and thiobarbituric acid active products in the conditions of gastric ulceration induced by stress.

The effects of baicalein on gastric mucosal ulcerations in mice: Protective pathways and anti-secretory mechanisms

Many flavonoids have been shown to present good results for the treatment of gastric ulcers. Baicalein, a bioactive flavonoid derived from the Scutellaria baicalensis Georgi root, possesses several biological effects, such as anti-inflammatory and antioxidant. This study was conducted to assess the gastroprotective properties of baicalein. Anti-ulcerogenic assay was performed using the protocol of ulcer induced by ethanol/HCl in mice; then, the role of presynaptic α₂-receptors, sulfhydryl (SH) compounds, nitric oxide (NO), prostaglandin (PG) and ATP-sensitive K⁺ (K_ATP) channels in gastroprotection of baicalein was investigated. The levels of reduced glutathione (GSH) and the myeloperoxidase (MPO) activity were measured in the gastric mucosa. Parameters of gastric secretion (volume, [H⁺] and pH) were determined with or without the presence of the secretagogue agent histamine, as well as mucus in gastric contents, by the pylorus ligation model. In vitro H⁺,K⁺-ATPase activity was also determined. Baicalein (10, 30 and 100 mg/kg) exhibited a dose related gastroprotective effect (P < 0.001) against acidified ethanol-induced lesions. The intraperitoneal treatment of mice with a α₂-adrenoreceptor antagonist (yohimbine; 2 mg/kg), a SH compounds blocker (N-ethylmaleimide, NEM; 10 mg/kg), a non-selective inhibitor of NO synthase (N_w-nitro-L-arginine methyl ester hydrochloride, L-NAME; 10 mg/kg), a non-selective inhibitor of cyclo-oxygenase (indomethacin; 10 mg/kg) or a K_ATP channel blocker (glibenclamide; 10 mg/kg) was able to reverse (P < 0.001) the gastroprotective response caused by baicalein (30 mg/kg). Baicalein (30 mg/kg; P < 0.05) was able to increase GSH levels and decreasing MPO activity. The intraduodenal treatment with baicalein (30 and 100 mg/kg) significantly increased (P < 0.05) the gastric mucus secretion. Additionally, the treatment with baicalein reduced (30 and 100 mg/kg; P < 0.05) the secretion volume and total acid secretion, and also increased (10, 30 and 100 mg/kg; P < 0.001) the pH value, after pylorus ligature. Baicalein (30 mg/kg) was also effective in inhibiting the effects of histamine on gastric secretion (volume, [H⁺] and pH; P < 0.001). Baicalein at 10 and 30 μg/mL showed anti-H⁺,K⁺-ATPase activity. In conclusion, the present results provide convincing evidence that baicalein could be used as a cytoprotective (preventive effect) and anti-ulcerogenic (anti-secretory effect) agent in the gastric ulcers.

Gastroprotective effects of sulforaphane and thymoquinone against acetylsalicylic acid-induced gastric ulcer in rats

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) commonly cause gastric ulcers (GUs). We investigated the effects of sulforaphane (SF) and thymoquinone (TQ) in rats with acetylsalicylic acid (ASA)-induced GUs.

MATERIALS AND METHODS

Thirty-five male Wistar-Albino rats were divided into five groups: control; ASA; ASA with vehicle; ASA + SF; and ASA + TQ. Compounds were administered by oral gavage before GU induction. GUs were induced by intragastric administration of ASA. Four hours after GU induction, rats were killed and stomachs excised. Total oxidant status, total antioxidant status, total thiol, nitric oxide, asymmetric dimethylarginine, tumor necrosis factor-alpha levels, superoxide dismutase activity, and glutathione peroxidase activity in tissue were measured. Messenger RNA expression of dimethylarginine dimethylaminohydrolases, heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2, and nuclear factor kappa-light-chain-enhancer of activated B cells were analyzed. Renal tissues were evaluated by histopathologic and immunohistochemical means.

RESULTS

SF and TQ reduced GU indices, apoptosis, total oxidant status, asymmetric dimethylarginine, and tumor necrosis factor-alpha levels, nuclear factor kappa-light-chain-enhancer of activated B cells, and inducible nitric oxide synthase expressions (P < 0.001, P = 0.001). Both examined compounds increased superoxide dismutase activity, glutathione peroxidase activity, total antioxidant status, total thiol, nitric oxide levels, endothelial nitric oxide synthase, dimethylarginine dimethylaminohydrolases, HO-1, nuclear factor erythroid 2-related factor 2, and HO-1 expressions (P < 0.001).

CONCLUSIONS

These results suggest that pretreatment with SF or TQ can reduce ASA-induced GUs via anti-inflammatory, antioxidant, and antiapoptotic effects. These compounds may be useful therapeutic strategies to prevent the gastrointestinal adverse effects that limit nonsteroidal anti-inflammatory drugs use.