Protective Effect of Flos Lonicerae against Experimental Gastric Ulcers in Rats: Mechanisms of Antioxidant and Anti-Inflammatory Action

Gastroprotective Effect of 2,3-Dimethylquinoxaline Against Indomethacin-Induced Gastric Ulcer in Rat

Background

Gastric ulcers pose a significant health risk due to an imbalance between protective and aggressive factors on the mucous membrane. Nonsteroidal anti-inflammatory drug (NSAID)-induced gastric damage affects 25% of users. Quinoxaline compounds, known for their diverse biological properties, have potential applications in cancer therapy and as antimicrobial agents targeting various pathogens.

Objective

Our study aimed to investigate the impact of DMQ on gastroprotective mechanisms in an experimental model of indomethacin-induced gastric ulcer.

Methods

Thirty male Wistar rats were randomly assigned to five groups. Group 1 served as the control, while Group 2 received a single oral dose of IND (30 mg/kg). Groups 3 and 4 received oral DMQ (30 mg/kg and 60 mg/kg, respectively) for three days, with the final dose administered intragastrically one hour before IND administration. Group 5 received esomeprazole (30 mg/kg) orally for three days, with the final dose given one hour before IND administration. Rats were sacrificed four hours after IND induction.

Results

Indomethacin-induced ulcers were associated with epithelial damage and blood streaks on the gastric mucosa. However, DMQ significantly decreased levels of inflammatory biomarkers (TNF-α, IL-6, Cox-2, IFN-γ, and IL-β1) while increasing gastroprotective mediator prostaglandin E2 (PGE2) and mucin levels. Histopathological analysis revealed a significant reduction in ulcer-induced pathological alterations and upregulation of tumor suppressor genes (NF-κB levels) following DMQ treatment. Rats treated with Indo+DMQ showed a significant decrease in ulcer index compared to the Indo group, with mild injuries observed.

Conclusion

DMQ demonstrated promising gastroprotective effects against IND-induced gastric ulcers, as evidenced by alterations in histopathological data and upregulation of gene expression.

Protective Effect of Fustin Against Ethanol-Activated Gastric Ulcer via Downregulation of Biochemical Parameters in Rats

The fustin plant-derived bioflavonoid obtained from a common plant known as lacquer tree from family Anacardiaceae, formally known as Rhus verniciflua Stokes, is known to exert a variety of therapeutic properties. The current investigation proved the anti-ulcerative property of fustin on ethanol-induced gastric ulcers in an experimental animal model. The fustin 50 and 100 mg/kg was studied in an experimental rat model by performing an 8 day protocol. The ulcer index, pH, total acidic content, and biochemical parameters such as glutathione (GSH), superoxide dismutase (SOD), catalase activity (CAT), malondialdehyde (MDA), interleukin-1β, prostaglandin E-2, tumor necrosis factor-α (TNF-α), myeloperoxidase, and nitric oxide (NO) in serum were measured. The gastric parameter such as ulcer index, pH, and acidic content was maintained in the fustin groups compared to the ethanol control group. Clinical presentation of gastric ulcers includes a significant increase in serum levels, GSH, SOD, and CAT and decreased MDA, TNF-α, interleukin-1β, and prostaglandin E-2 parameters in contrast to normal groups. The treatment regimen with fustin has significantly restored all serum parameters in test groups. The current study helps to develop reasonable phytochemical options for the innervations of chemical-induced gastric ulcers.

Antiulcer activity of proanthocyanidins is mediated via suppression of oxidative, inflammatory, and apoptotic machineries

Gastric ulcer (GU) is a lesion in the gastric mucosa associated with excessive oxidative damage, inflammatory response, apoptotic events, and irritation which may develop into cancer. However, medications commonly used in GU treatment cannot normalize gastric mucosa, while causing several adverse effects. Proanthocyanidins (PAs) are dietary flavonoids with numerous biological and pharmacological activities. In the current investigation, we studied the potential anti-ulcerative activity of PAs against acidified ethanol (HCl/ethanol)-caused gastric ulceration. Fifty male albino Wistar rats were allocated into five equal groups: control, HCl/ethanol (3 mL/kg), lansoprazole (LPZ, 30 mg/kg) + HCl/ethanol, and PAs (100 and 250 mg/kg) + HCl/ethanol. LPZ and PAs were applied one week before gastric ulcer induction. PAs pretreatment notably reduced gastric mucosal macroscopic and microscopic pathological changes in a dose-dependent manner. Additionally, PAs activated the innate antioxidant molecules including glutathione and its derived antioxidants (glutathione peroxidase and glutathione reductase), along with superoxide dismutase and catalase, while attenuating pro-oxidant formation, including malondialdehyde and nitric oxide. Interestingly, PAs supplementation at a higher dose suppressed gastric inflammatory and apoptotic responses, as demonstrated by the reduced levels of interleukin-1β, interleukin-6, tumor necrosis factor alpha, high-mobility group box 1, cyclooxygenase 2, prostaglandin E2, nuclear factor kappa-B, Bcl-2-associated X protein, and caspase-3, while B cell lymphoma 2 was elevated. Hence, PAs could exhibit antiulcer activity by protecting gastric tissue from the development of oxidative damage, inflammatory responses, and apoptosis events associated with ulceration. PRACTICAL IMPLICATIONS: Gastric ulcer is a lesion in the gastric mucosal layer associated with excessive inflammatory response, apoptotic events, oxidative damage, and irritation, and may develop into cancer with about 5%-10% morbidity rate. However, medications commonly used in GU treatment cannot normalize gastric mucosa, while causing several adverse effects. Therefore, new therapeutic approaches are needed to treat or prevent gastric ulceration. Proanthocyanidins (PAs, condensed tannins) are dietary flavonoids found in abundance in different plant species, including their fruits, bark, and seeds. Due to their potent antioxidative activity, PAs have been applied to prevent or treat oxidative stress-related diseases, including cancer, as well as metabolic, neurodegenerative, cardiovascular, and inflammatory disorders. Here, we examine the potential therapeutic role of proanthocyanidins (PAs) against acidified ethanol-induced gastric ulcer in rats through evaluating oxidative challenge, inflammatory response, apoptotic events, and histopathological changes in the gastric tissue.

Gastric Ulcer Healing Property of Bryophyllum pinnatum Leaf Extract in Chronic Model In Vivo and Gastroprotective Activity of Its Major Flavonoid

Gastric ulcer is a common disease that develops complications such as hemorrhages and perforations when not properly treated. Extended use of drugs in the treatment of this pathology can provoke many adverse effects. Therefore, finding medicinal plants with gastroprotective and mucosal healing properties has gained increasing interest. Bryophyllum pinnatum (Crassulaceae), popularly known in Brazil as “saião” or “coirama,” has been used to treat inflammatory disorders. It is rich in flavonoids, and quercetin 3-O-α-L-arabinopyranosyl-(1→2)-O-α-L-rhamnopyranoside-Bp1 is its major compound. In this study, we aimed to investigate ulcer healing properties of B. pinnatum against an acetic acid–induced chronic ulcer model and the gastroprotective activity of Bp1 against gastric lesions induced by ethanol and indomethacin. Ultrafast liquid chromatography was used to quantify the main compounds (mg/g of the extract)—quercetin 3-O-α-L-arabinopyranosyl-(1→2)-O-α-L-rhamnopyranoside (33.12 ± 0.056), kaempferol 3-O-α-L-arabinopyranosyl-(1→2)-O-α-L-rhamnopyranoside (3.98 ± 0.049), and quercetin 3-O-α-L-rhamnopyranoside (4.26 ± 0.022) and showed good linearity, specificity, selectivity, precision, robustness, and accuracy. In vivo studies showed that treatment with the extract at 250 and 500 mg/kg stimulated the healing process in the gastric mucosa with significant ulceration index reduction, followed by improvement in the antioxidant defense system [increased glutathione (GSH) levels, decreased superoxide dismutase upregulation, and malondialdehyde (MDA) levels]. Moreover, the extract decreased interleukin-1β and tumor necrosis factor-a levels and myeloperoxidase (MPO) activity, increased interleukin 10 levels, showed a cytoprotective effect in histological analyzes and also downregulated the expression of cyclooxygenase-2 and NF-κB (p65). The pretreatment with Bp1 at a dose of 5 mg/kg reduced gastric lesions in the ethanol and indomethacin models, increased GSH, and decreased MDA levels. In addition, the pretreatment decreased MPO activity, interleukin-1β and tumor necrosis factor-α levels, while also showing a cytoprotective effect in histological analyzes. Our study suggests that treatment with B. pinnatum extract showed a higher inhibition percentage than pretreatment with the Bp1. This might in turn suggest that Bp1 has gastroprotective activity, but other compounds can act synergistically, potentiating its effect. We conclude that B. pinnatum leaf extract could be a new source of raw material rich in phenolic compounds to be applied in food or medicine.

SR-5, the specific ratio of Korean multi-herbal formula: An evaluation of antiulcerogenic effects on experimentally induced gastric ulcers in mice

Purpose

Previously, we demonstrated that the specific ratio of Korean multi-herbal formula (SR-5) exhibits hepatoprotective properties against ethanol-induced hepatic damage in rats. Chronic and excessive alcohol consumption is a major etiological factor involved in gastric disease and ulcer development induced by the inflammatory response and oxidative stress.

Methods

The present study evaluated the gastroprotective effects of SR-5 (100, 150, and 200 mg/kg) against hydrochloride acid/ethanol (HCl/EtOH)-induced and indomethacin/hydrochloride acid (INDO/HCl)-induced gastritis in a mouse model and the mechanisms involved.

Results

All the tested doses of SR-5 significantly inhibited gastric lesions in the HCl/EtOH-induced ulcer model mice. Similarly, all the tested doses of SR-5 significantly inhibited gastric lesions in the INDO/HCl-induced ulcer model mice. Furthermore, mice pretreated with SR-5 had significantly increased gastric levels of enzymatic and nonenzymatic antioxidants, namely, catalase (CAT) and glutathione (GSH), with concomitant reductions in malondialdehyde (MDA) and reactive oxygen species (ROS) levels compared with those in the HCl/EtOH or INDO/HCl group. SR-5 suppressed the expression of nuclear factor-kappa B (NF-κB)/p65, inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2) to their normal values.

Conclusion

These findings are the first to demonstrate the powerful protective effect of SR-5 against gastric injury development and provide hope for clinical application.

Antiulcer Activity of Steamed Ginger Extract against Ethanol/HCl-Induced Gastric Mucosal Injury in Rats

Ginger (Zingiber officianale), the most widely consumed species, is traditionally used as a folk medicine to treat some inflammatory diseases in China and Korea. However, the functional activity of steamed ginger extract on gastric ulcers has not been previously explored. The present study aimed to investigate antiulcer activity of steamed ginger extract (GGE03) against ethanol (EtOH)/HCl-induced gastric ulcers in a rat model. GGE03 (100 mg/kg) was orally administered for 14 days to rats before oral intubation of an EtOH/HCl mixture to induce gastric damage. Pretreatment with GGE03 markedly protected the formation of microscopic pathological damage in the gastric mucosa. Further, administration of GGE03 significantly increased mucosal total nitrate/nitrite production in gastric tissues, and elevated total GSH content, catalase activity and superoxide dismutase (SOD) expression as well as decreasing lipid peroxidation and myeloperoxidase (MPO) activity. Underlying protective mechanisms were examined by assessing inflammation-related genes, including nuclear factor-κB (NF-κB), prostaglandin E2 (PGE2), and pro-inflammatory cytokines levels. GGE03 administration significantly reduced the expression of NF-κB and pro-inflammatory cytokines. Our findings suggest that GGE03 possesses antiulcer activity by attenuating oxidative stress and inflammatory responses.

Chemical constituents and gastro-protective potential of Pachira glabra leaves against ethanol-induced gastric ulcer in experimental rat model

Gastric ulcer is a very common illness that adversely affects a significant number of people all over the globe. Phytochemical investigation of P. glabra leaf alcohol extract (PGLE) resulted in the isolation and Characterization of a new nature compound, quercetin-3- O-α -L-rhamnosyl-(1'''-6'')-(4''- O -acetyl)-β -D-galactoside (4), in addition to seven known compounds. They are ferulic acid (1), p- coumaric acid (2), quercetin 3-O-α-L-rhamnoside-3'-O-β-D-glucoside (3), quercetin-3- O-α -L-rhamnosyl-(1'''-6'')-(4''- O -acetyl)- β -Dgalactoside (4), quercetin-3- O-β -D-galactoside (5), 7-hydroxy maltol-3-O-β-D-glucoside (6), maltol-3- O-β -D-glucoside (7), and methyl coumarate (8) that were first to be isolated from the genus Pachira. PGLE demonstrated in vitro anti-Helicobacter pylori activity. Moreover, the in vivo gastroprotective assessment of PGLE at different dosses, 100, 200, and 400 mg/kg against ethanol induced ulceration revealed a dose-dependent gastroprotection comparable to omeprazole. PGLE attenuated gastric lesions and histopathological changes triggered by ethanol. Interestingly, PGLE exhibited an anti-inflammatory effect through down-regulating the expression of nuclear factor-ĸB and pro-inflammatory enzyme cyclooxygenase-2 in the ulcer group. It also hindered apoptosis through decreasing Bax and increasing Bcl-2 expression hence decreasing Bax/Bcl2 ratio with a subsequent reduction in caspase 3 expression. Collectively, P. glabra is a rich reservoir of various phytochemicals reflecting a promising potential for alleviation of gastric ulcer through the mediation of inflammatory and apoptotic cascades.

Antiulcerogenic effect of Cuphea ignea extract against ethanol-induced gastric ulcer in rats

BACKGROUND

Cuphea ignea is one of the herbal resources belonging to Lythraceae family. Some species of this family have been used traditionally in South and Central America's folk medicine for treating stomach disorders. Therefore, the present study was performed to evaluate the gastropreventive effect of aqueous ethanolic extract of C. ignea aerial parts on ethanol-induced gastric ulcer.

METHODS

Gastric ulcers were induced in Sprague Dawley rats using one oral dose of absolute ethanol (1.5 mL/rat). The C. ignea aerial parts extract at doses of 250 and 500 mg/kg body weight and ranitidine (a reference drug) at a dose of 30 mg/kg body weight were orally administrated daily for 7 days before ulcer induction. One hour after ethanol administration blood samples were collected and then stomachs of sacrificed rats were subjected to biochemical, macroscopic and microscopic studies.

RESULTS

Oral administration of C. ignea extract significantly attenuated gastric ulcer as revealed by significant reduction in the gastric ulcer index and volume of gastric juice while significantly increased preventive percentage, gastric pH value and pepsin activity. Pre-treatment of C. ignea extract markedly improved the serum level of TNF-α, the gastric MPO activity and NO content. Furthermore, C. ignea pre-treatment significantly increased the gastric levels of enzymatic and non- enzymatic antioxidants namely CAT, SOD, GSH-Px, and GSH with concomitant reduction in MDA level compared with those in the ethanol group. These results were further supported by histopathological findings which revealed the curing effect of C. ignea on the hemorrhagic shock induced by ethanol toxicity.

CONCLUSIONS

C. ignea extract showed a potential gastroprotective effect on ethanol-induced gastric ulcer, and its effect may be mediated through suppression of oxidative stress and gastric inflammation.

Potent therapeutic effects of ruscogenin on gastric ulcer established by acetic acid

BACKGROUND/OBJECTIVE

The present study investigated the potent therapeutic effects of Ruscogenin, main steroid sapogenin of traditional Chinese plant called 'Ophiopogon japonicas', on chronic ulcer model established with acetic acid in rats.

METHODS

24 rats were attenuated to the sham (2 ml/kg/day isotonic solution), control (untreated ulcer) and treatment (3 ml/kg/day ruscogenin) groups. After treatment for 2 weeks, gastric tissues were collected and prepared for light microscopic (H&E), immunohistochemical (Collagen I, III and IV) and biochemical analysis [Epidermal growth factor (EGF), Prostaglandin E2 (PGE2), Tumor Necrosis Factor alpha (TNF-α), Interleukin 6 and 8 (IL-6 and IL-8), Lipid Peroxidase (LPO), Myeloperoxidase (MPO), Glutathione (GSH) and Glutathione Peroxidase (GSH-Px)] and transmission electron microscopy (TEM).

RESULTS

Macroscopic scoring showed that the ulceration area of ruscogenin-treated group decreased compared with control group. Immunohistochemical analysis revealed ruscogenin ameliorated and restored the levels of Collagen I and IV to the levels of sham group. Tissue levels of EGF and PGE2 enhanced significantly in untreated ulcer group while were higher in treated ulcer group than the control group. TNF-α, IL-6, IL-8, LPO, MPO levels increased significantly in control group whereas decreased in treated rats after ruscogenin treatment. However, levels of GSH and GSH-Px increased significantly in treatment group. TEM showed chief cells and parietal cells of ulcer group having degenerated organelles while ruscogenin group had normal ultrastructure of cells.

CONCLUSION

There are potent anti-inflammatory and anti-oxidant effects of ruscogenin on gastric ulcer and may be successfully used as a safe and therapeutic agent in treatment of peptic ulcer.

Protective Effects of Aqueous Extracts of Flos lonicerae Japonicae against Hydroquinone-Induced Toxicity in Hepatic L02 Cells

Hydroquinone (HQ) is widely used in food stuffs and is an occupational and environmental pollutant. Although the hepatotoxicity of HQ has been demonstrated both in vitro and in vivo, the prevention of HQ-induced hepatotoxicity has yet to be elucidated. In this study, we focused on the intervention effect of aqueous extracts of Flos lonicerae Japonicae (FLJ) on HQ-induced cytotoxicity. We demonstrated that HQ reduced cell viability in a concentration-dependent manner by administering 160 μmol/L HQ for 12 h as the positive control of cytotoxicity. The aqueous FLJ extracts significantly increased cell viability and decreased LDH release, ALT, and AST in a concentration-dependent manner compared with the corresponding HQ-treated groups in hepatic L02 cells. This result indicated that aqueous FLJ extracts could protect the cytotoxicity induced by HQ. HQ increased intracellular MDA and LPO and decreased the activities of GSH, GSH-Px, and SOD in hepatic L02 cells. In addition, aqueous FLJ extracts significantly suppressed HQ-stimulated oxidative damage. Moreover, HQ promoted DNA double-strand breaks (DSBs) and the level of 8-hydroxy-2'-deoxyguanosine and apoptosis. However, aqueous FLJ extracts reversed HQ-induced DNA damage and apoptosis in a concentration-dependent manner. Overall, our results demonstrated that the toxicity of HQ was mediated by intracellular oxidative stress, which activated DNA damage and apoptosis. The findings also proved that aqueous FLJ extracts exerted protective effects against HQ-induced cytotoxicity in hepatic L02 cells.

Anti-Inflammatory and Gastroprotective Roles of Rabdosia inflexa through Downregulation of Pro-Inflammatory Cytokines and MAPK/NF-κB Signaling Pathways

Globally, gastric ulcer is a vital health hazard for a human. Rabdosia inflexa (RI) has been used in traditional medicine for inflammatory diseases. The present study aimed to investigate the protective effect and related molecular mechanism of RI using lipopolysaccharide (LPS)-induced inflammation in RAW 246.7 cells and HCl/EtOH-induced gastric ulcer in mice. We applied 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), nitric oxide (NO), reactive oxygen species (ROS), histopathology, malondialdehyde (MDA), quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry (IHC), and Western blot analyses to evaluate the protective role of RI. Study revealed that RI effectively attenuated LPS-promoted NO and ROS production in RAW 246.7 cells. In addition, RI mitigated gastric oxidative stress by inhibiting lipid peroxidation, elevating NO, and decreasing gastric inflammation. RI significantly halted elevated gene expression of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthetase (iNOS), and cyclooxygenase-2 (COX-2) in gastric tissue. Likewise, RI markedly attenuated the mitogen-activated protein kinases (MAPKs) phosphorylation, COX-2 expression, phosphorylation and degradation of inhibitor kappa B (IκBα) and activation of nuclear factor kappa B (NF-κB). Thus, experimental findings suggested that the anti-inflammatory and gastroprotective activities of RI might contribute to regulating pro-inflammatory cytokines and MAPK/NF-κB signaling pathways.

Activity of Brucea javanica oil emulsion against gastric ulcers in rodents

The present study aims to investigate the gastroprotective effect of Brucea javanica oil emulsion (BJOE) in animals. Gastroprotective potential of BJOE was studied on absolute ethanol, aspirin, reserpine and restraint plus water immersion-induced gastric ulcers in mice as well as glacial acetic acid (GAA) and pyloric ligation (PL)-induced gastric ulcers in rats. Except for ulcer scores, total acidity as well as pepsin activity as for the PL-induced gastric ulcer model and ulcer incidence as for the GAA-induced gastric ulcer model were also determined. Histopathological evaluation as for aspirin, reserpine, PL-induced models was conducted. Results showed that BJOE significantly (P < 0.05) reduced ulcer index in the mouse and rat models in a dose-dependent manner. It had significant (P < 0.05) suppressive effect on total activity of gastric juice as well in PL-induced model. Histopathological examination for the stomach samples confirmed the findings in the aspirin, reserpine or PL-induced gastric lesion models, which showed relatively complete mucosa structure and less inflammation. It is concluded that BJOE could be effective on gastric ulcer in rodents and its gastroprotective activity might be related to antioxidant, anti-inflammatory ability and promote gastric mucus secreted. The results may provide beneficial basis for increasing BJOE's clinical indication in future.

Toll-like receptor 4 protects against stress-induced ulcers via regulation of glucocorticoid production in mice

Stress-induced gastric ulcer is an important life-threatening condition, while the molecular basis of its development is incompletely understood. Toll-like receptor 4 (TLR4), an innate immune pattern recognition receptor, can induce pro-inflammatory transcription, aggravating a stress ulcer. The present study found that TLR4 played a protective role in a mouse model of water immersion (23 °C) restraint stress. Wild-type (WT) and TLR4^-/- male mice were respectively divided into five groups (5 per group), and exposed to the stressor for 0, 0.5, 1, 2, or 4 hours. Gastric ulcer index, determined post mortem, increased with time in both types of mice but was greater in TLR4^-/- mice. Furthermore, increased serum cortisol and corticosterone concentrations were observed in WT mice only, and such increases were detected only in WT mice 4 h after lipopolysaccharide (LPS) treatment (2 mg/kg, intraperitoneal injection). Moreover, the administration of cortisol alleviated the gastric injury in TLR4^-/- mice. Western blotting showed expression in the adrenal of P450scc (CYP11A1), the first rate-limiting enzyme in the synthesis of steroids, was increased 4 h after water immersion restraint stress or LPS treatment in WT mice, but was conversely decreased in TLR4^-/- mice after either stressor. Furthermore, in adrenal glands of TLR4^-/- mice, structural distortion of mitochondria (which contain CYP11A1) was found with electron microscopy, and lack of lipid-storing droplets was found using light microscopy on adrenal cryosections stained with Oil red O. These data indicate that TLR4 plays a protective role in stress-induced gastric ulcer that is exerted via impacting synthesis of glucocorticoid in the adrenal gland.

Protective Effect of Yinhua Miyanling Tablet on Lipopolysaccharide-Induced Inflammation through Suppression of NLRP3/Caspase-1 Inflammasome in Human Peripheral Blood Mononuclear Cells

Yinhua Miyanling Tablet (YMT), the Chinese formula, has long been administrated in clinical practice for the treatment of acute pyelonephritis and acute urocystitis. In the current study, we aimed to investigate the anti-inflammatory effect of YMT in vitro and to evaluate the association between anti-inflammation and innate immune response. Human peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll density gradient centrifugation and then were stimulated by Lipopolysaccharide (LPS). The differential gene expression of inflammation-related genes after drug administration was assessed using PCR array, and the protein levels of differential genes were measured by ELISA and Western blot. The result showed that YMT significantly inhibited the expression of NLRP3, Caspase-1, and the downstream cytokine IL-1β and suppressed the production of inflammatory mediators TNF-α, IL-6, IL-10, and MCP-1 in a dose-dependent manner compared to the LPS group (P < 0.01). The finding indicated that YMT exhibited anti-inflammatory effect in vitro by suppressing the NLRP3/Caspase-1 inflammasome, and that may have therapeutic potential for the treatment of inflammatory diseases.

Protective effects of Weilikang decoction on gastric ulcers and possible mechanisms

Although Weilikang decoction (WLK) has been used for gastric ulcer (GU) therapy in a clinical setting with good curative effect for >20 years, the mechanism remains unclear. Several GU animal models, induced by ethanol, hydrochloric acid, aspirin, pylorus ligation, acetic acid and indomethacin, were used to investigate the gastroprotective effects of WLK decoction. Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), indomethacin, and N-ethylmaleimide (NEM) were pretreated, respectively, to investigate the action mechanism. Real-time polymerase chain reaction and Western blot analysis methods were used to determine the effects of WLK on indomethacin-induced GUs. The WLK-administered groups (2.5, 1.25 and 0.625 g/kg) significantly reduced the GU areas induced by ethanol, hydrochloric acid and aspirin. Furthermore, the effects could be quenched by L-NAME and NEM, but not by indomethacin. The 2.5 and 1.25 g/kg WLK groups showed significantly decreased effects on GU areas induced by pylorus ligation and acetic acid. WLK treatment significantly decreased mRNA expression on cyclooxygenase (COX)-1, COX-2, interleukin-6, tumor necrosis factor α and inducible nitric oxide synthase (iNOS) mRNA, but showed no effect on endothelial nitric oxide synthase mRNA expression. Western blot analysis result showed that WLK-treated groups markedly downregulated COX-2 protein expression. The anti-ulcer potential of WLK can be primarily attributed to its regulatory effects on nitric oxide, sulfhydryl compounds, and reduction effect on mucosal expression of proinflammatory cytokines.

Vanillin abrogates ethanol induced gastric injury in rats via modulation of gastric secretion, oxidative stress and inflammation

Vanillin is commonly used as an additive in food, medicine and cosmetics, but its effect has not yet been studied in gastric injury. Therefore the effect of vanillin was studied in experimental gastric ulcer. Gastric secretion and acidity were studied in pylorus ligated rats. Ulcer index, levels of gastric mucus, malondialdehyde (MDA), myeloperoxidase activity (MPO), expression of nuclear factor kappa B (NF-κB) p65, and histopathological changes were determined in ethanol induced gastric ulcer. Pre treatment with vanillin significantly reduced gastric secretion (P < 0.001) and acidity (P < 0.0001) and gastric ulcer index scores (P < 0.001). and augmented the gastric mucosal defense. Vanillin significantly restored the depleted gastric wall mucus levels (P < 0.0001) induced by ethanol and also significantly attenuated ethanol induced inflammation and oxidative stress by the suppression of gastric MPO activity (P < 0.001), reducing the expression of NF-κB p65 and the increased MDA levels (P < 0.001). Vanillin was also effective in alleviating the damage to the histological architecture and the activation of mast cells induced by ethanol.

Together the results of this study highlight the gastroprotective activity of vanillin in gastric ulcers of rats through multiple actions that include inhibition of gastric secretion and acidity, reduction of inflammation and oxidative stress, suppression of expression of NF-κB, and restoration of the histological architecture.