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Background: The gastro-intestinal disorders, induced by the NSAIDs including indomethacin (IND) remain unresolved medical problems. Herein, we disclose allylpyrocatechol (APC) as a potential agent against IND-gastropathy and rationalize its action mechanistically., Methods: Mice were pre-treated with APC for 1h followed by IND (18mgkg(-1)) administration, and the ulcer-prevention capacity of APC was evaluated on the 3rd day by histology. Its effect on the inflammatory (MPO, cytokines, adhesion molecules), ulcer-healing (COX, prostaglandins, growth factors and their receptors) and signaling parameters (NF-κB and MAPKs) were assessed by immunoblots/mRNA, and ELISA at the time points of their maximal changes due to IND administration., Results: IND induced oxidative stress, triggering mucosal TNF-α that activated NF-κB and JNK MAPK signaling in mice. These increased the pro-inflammatory biochemical parameters, but reduced the healing factors. APC reversed all the adverse effects to prevent gastric ulceration. APC (5mgkg(-1)), trolox (50mgkg(-1)) and NAC (250mgkg(-1)) showed similar protection that was better than that by misoprostol (5μgkg(-1)) and omeprazole (3mgkg(-1))., Conclusions: The anti-ulcer effect of APC can be primarily attributed to its antioxidant action that helped in controlling various inflammatory parameters and augmenting angiogenesis., General Significance: Given that APC is an effective, non-toxic antioxidant with appreciable natural abundance, further evaluation of its pharmacokinetics and dynamics would help in promoting it as a new anti-inflammatory agent., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Management of the gastro-toxicity of non-steroidal anti-inflammatory drugs (NSAIDs) remains a crucial problem, because the commercially available anti-ulcer drugs have side effects and are often expensive. Hence, the potential of a new water-soluble GPx mimic, DL-trans-3,4-dihydroxy-1-selenolane (DHS(red)) in healing the indomethacin-induced stomach ulceration in mice was examined. Administration of indomethacin (18 mg/kg, p. o.) induced ulceration in the glandular portion of the gastric mucosa, accompanied by increased lipid peroxidation (1.3-fold, p <0.001) and protein oxidation (1.5-fold, p < 0.001), depletion of thiol-defense (42.5%, p < 0.01), plasma total antioxidant status (53.4%, p < 0.001) and mucin (47.5%, p < 0.01), as well as reduced expressions of cyclooxygenases and prostaglandin synthesis (54.7%, p < 0.001) in the gastric tissues of mice. Daily oral administration of DHS(red) (2.5 mg/kg) or omeprazole (Omez) (3 mg/kg) for 3 days respectively produced ˜74% and 69% (p < 0.001) healing of the acute gastric ulceration. The test samples also significantly reversed all the adverse effects of indomethacin on the biochemical parameters. Apparently, the gastric ulcer healing action of DHS(red) and Omez was due to their antioxidant action and their ability to protect mucin and augment PG synthesis by upregulation of the COX isozymes. The results suggested that the non-toxic and inexpensive compound, DHS(red), may be a good candidate for further evaluation as a potent anti-ulcer drug.

The probable cross talk among large numbers of inflammatory and angiogenic parameters in indomethacin (IND)-induced gastropathy and the associated signaling mechanism were studied in a mouse model. A single dose of IND (18 mg/kg, po) produced robust gastric ulceration in mice without any mortality, which peaked on the third day, but started healing from the fifth day onward. The ulceration was associated with increased myeloperoxidase activity and expression of proinflammatory (TNF-α, adhesion molecules, COX-2) and antiangiogenic (endostatin) parameters. The levels of proangiogenic factors such as COX-1, prostaglandin E, VEGF, and von Willebrand factor VIII were downregulated by IND. Our results revealed that although the maximal and minimal levels of these parameters were attained sequentially at different time points, TNF-α upregulation was the primary event to initiate and induce gastric ulceration. IND also activated NF-κB and all the MAP kinases, but only the inhibitors of TNF-α, NF-κB, and JNK MAP kinase could abrogate the IND-induced damages. Further TNF-α inhibition also reduced the IND-mediated activation of NF-κB and JNK MAP kinase. All this evidence strongly suggests that mitigation of TNF-α may offer a potential solution to IND-mediated gastropathy., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Management of the gastric toxicity of non-steroidal anti-inflammatory drugs (NSAIDs) remains a crucial problem because the commercially available drugs have side effects and are often expensive. Therefore, we examined the potential of the green tea-derived polyphenol epigallocatechin gallate (EGCG) to treat indomethacin-induced stomach ulcers in mice. Administration of indomethacin (18 mg/kg, po) to mice induced ulceration in the glandular portion of the gastric mucosa, accompanied by increased lipid peroxidation (LPO) and protein oxidation and reductions in thiol defense, mucin, cyclooxygenase (COX) expression and prostaglandin (PG) synthesis in the gastric tissues. Daily oral administration of EGCG (2 mg/kg) or omeprazole (3 mg/kg) for 3 days produced similar (≈ 72-75%, p < 0.001) beneficial effects on the acute gastric ulceration. Treatment with the test samples partially reversed all the adverse oxidative effects of indomethacin. In addition, EGCG, but not omeprazole, enhanced expression of the COX isoforms and PG synthesis. The results suggest that the non-toxic and inexpensive tea polyphenol EGCG may be an excellent candidate for further evaluation as a potent anti-ulcer drug.

The cytoprotective action of the synthetic resveratrol (Resv) congener, E-3,3′,5,5′-tetrahydroxystilbene (designated as HST-1) against indomethacin (IND)-induced stomach ulceration has been established using a mice model. HST-1 reversed the adverse effects of IND on several inflammatory (myeloperoxidase, cytokines, adhesion molecules etc.) and ulcer-healing (cyclooxygenases, prostaglandin, growth factors and their receptors etc.) parameters in mice. More importantly, HST-1 down-regulated TNF-α and the TNF-α-mediated activation of NF-κB and JNK/MAPK pathways that are the key determinants in the IND-gastropathy. The effect of HST-1 on all these factors was significantly better than that of Resv, misoprostol, and omeprazole. HST-1 also did not induce small intestinal mucosal injury, unlike some of the proton pump inhibitors. On the other hand, Resv reduced activation of the prosurvival ERK1/2 pathway that may explain its contraindicative property in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Background The importance of the arginine metabolism in gastric ulcer-healing is given relatively less attention. Hence the role of controlling this pathway by dl -trans-3,4-dihydroxy-1-selenolane (DHS red ) and omeprazole against indomethacin-induced stomach ulceration in mouse was investigated. Methods Swiss albino mice were ulcerated with indomethacin followed by treatment with the test samples, and the activities of myeloperoxidase (MPO), total nitric oxide synthase (NOS) and arginase, the expressions of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS), and the pro-/anti-inflammatory cytokine levels were assayed. NOS-inhibitors were also used to establish the biochemical mechanism. Results Indomethacin induced maximum ulceration in mice on the 3rd day, associated with reduced arginase activity, eNOS expression, along with increased MPO and total NOS activities, nitric oxide (NO) generation, iNOS expression, and pro-/anti-inflammatory (Th 1 /Th 2) cytokine ratio. Treatment with DHS red (2.5 mg kg − 1 × 3 days) restored the cytokine balance to shift the iNOS/NO axis to the arginase/polyamine axis as revealed from the increased arginase activity and eNOS expression, and reduced iNOS expression, total NOS activity and NO level. Conclusions The ulcer-healing property of DHS red , but not of omeprazole was due to a favorable pro-/anti-inflammatory cytokine ratio that shifted the arginine metabolism to the polyamine pathway and increased the eNOS/iNOS ratio. The healing action of omeprazole was not significantly associated with these parameters. General significance The shift in the ariginine-metabolism from the iNOS/NO axis to the arginase/polyamine axis is guided by Th 1/ Th 2 cytokines ratio and plays an important role in gastric ulcer-healing. The favourable effects of the non-toxic and water-soluble compound, DHS red on these pathways and other COX-dependent and antioxidative parameters suggested it to be a promising anti-ulcer formulation for further studies. [ABSTRACT FROM AUTHOR]

Management of the gastro-toxicity of non-steroidal anti-inflammatory drugs (NSAIDs) remains a crucial problem, because the commercially available anti-ulcer drugs have side effects and are often expensive. Hence, the potential of a new water-soluble GPx mimic, DL- trans-3,4-dihydroxy-1-selenolane (DHSred) in healing the indomethacin-induced stomach ulceration in mice was examined. Administration of indomethacin (18 mg/kg, p. o.) induced ulceration in the glandular portion of the gastric mucosa, accompanied by increased lipid peroxidation (1.3-fold, p <0.001) and protein oxidation (1.5-fold, p < 0.001), depletion of thiol-defense (42.5%, p < 0.01), plasma total antioxidant status (53.4%, p < 0.001) and mucin (47.5%, p < 0.01), as well as reduced expressions of cyclooxygenases and prostaglandin synthesis (54.7%, p < 0.001) in the gastric tissues of mice. Daily oral administration of DHSred (2.5 mg/kg) or omeprazole (Omez) (3 mg/kg) for 3 days respectively produced ˜74% and 69% ( p < 0.001) healing of the acute gastric ulceration. The test samples also significantly reversed all the adverse effects of indomethacin on the biochemical parameters. Apparently, the gastric ulcer healing action of DHSred and Omez was due to their antioxidant action and their ability to protect mucin and augment PG synthesis by upregulation of the COX isozymes. The results suggested that the non-toxic and inexpensive compound, DHSred, may be a good candidate for further evaluation as a potent anti-ulcer drug. [ABSTRACT FROM AUTHOR]

The modulation of the cyclooxygenase-independent pathway by black tea (BT) and its constituent theaflavins (TFs) during their healing action against indomethacin-induced stomach ulceration in mice was investigated. On the 3rd day of its administration, indomethacin (18 mg/kg) induced maximum stomach ulceration, which was associated with increased myeloperoxidase (MPO) activity (93.3%, p < 0.001), and inducible nitric oxide synthase (iNOS) expression (1.6-fold, p < 0.001), along with augmented levels of serum nitrite (1.5-fold, p < 0.001), selectins and cell adhesion molecules (CAMs), as well as reduced endothelial nitric oxide synthase (eNOS) expression (60%, p < 0.001). Treatment with BT (40 mg/kg) and TF (1 mg/kg) for 3 days reversed these parameters and provided excellent (78--81%) ulcer healing. However, alterations of NOS expressions and levels of selectins and CAMs were only partially responsible for the excellent healing capacity (∼∼80%) of omeprazole (3 mg/kg ×× 3 days). [ABSTRACT FROM AUTHOR]

Abstract: The role of the ariginine-metabolism in the healing action of the Piper betle phenol, allylpyrocatechol (APC) and omeprazole against indomethacin-induced stomach ulceration in mouse was investigated. Indomethacin (18 mg/kg) was found to induce maximum stomach ulceration in Swiss albino mice on the 3rd day of its administration, which was associated with reduced arginase activity (21.6%, P <0.05), endothelial nitric oxide synthase (eNOS) expression (72%, P <0.001), and IL-4 and TGF-β levels, along with increased inducible nitric oxide synthase (iNOS) (9.3 folds, P <0.001) expression, nitrite (2.29 folds, P <0.001), IL-1β and IL-6 generation. Besides providing comparable healing as omeprazole (3 mg/kg×3 days), APC (5 mg/kg×3 days) shifted the iNOS/NO axis to the arginase/polyamine axis as revealed from the increased arginase activity (73.1%, P <0.001), eNOS expression (67.8%, P <0.001), and reduced iNOS expression (65.6%, P <0.001) and nitrite level (53.2%, P <0.001). These can be attributed to a favourable anti-/pro-inflammatory cytokines ratio, generated by APC. The healing by omeprazole was however, not significantly associated with those parameters. [Copyright &y& Elsevier]