Current approaches to prevent NSAID-induced gastropathy--COX selectivity and beyond

2-Trifluoromethyl-2H-chromene ethers: The dual triumph of anti-inflammation and analgesia with minimal ulcer threat

In this report, we disclose the design and synthesis of a series of 2-trifluoromethyl-2H- chromene ethers as novel COX-2 inhibitors with low ulcerogenicity. Among them, 6-fluoro-3-(4-methoxyphenyl)-2-(2-(thiophen-3-yl)ethoxy)-2-(trifluoromethyl)-2H-chromene (E25) significantly suppressed LPS-induced release of NO and PGE2, expression of COX-2 and iNOS, and activation of NF-κB pathway. The inhibitory effect of E25 on human recombinant COX-2 (IC50 = 70.7 ± 4.7 nM) and molecular docking studies suggest that E25 functions as a COX-2 inhibitor. Moreover, the results of the cellular thermal shift assay also substantiate the interaction between E25 and COX-2. E25 manifests potent anti-inflammatory and analgesic efficacy on a par with or even superior to indomethacin in rodent models including carrageenan-induced paw edema, cotton pellet-induced granuloma, acetic acid-induced writhes, and adjuvant-induced arthritis. The possible mechanism of action of E25 might be to bind to COX-2 and suppress the NF-κB pathway as well as the expression of related proteins, thereby exerting anti-inflammatory and analgesic effects. Encouragingly, compared with indomethacin, E25 induces smaller areas and fewer ulcers, a lower level of inflammatory infiltration, a lower expression of MMP-9 and apoptosis of mucosal epithelial cells in rat gastric tissues. Overall, E25 and other analogues are promising candidates worthy of further investigation for the treatment of inflammation and pain, as well as other symptoms in which COX-2 and PGE2 play a role in their etiology.

3-(2-Trifluoromethyl-3-aryl-4H-chromen-4-yl)-1H-indoles: Mastering anti-inflammation and analgesia while mitigating gastrointestinal side effects

A series of 3-(2-trifluoromethyl-3-aryl-4H-chromen-4-yl)-1H-indoles (5-1 to 5-29) were developed and characterized. Most of compounds were found to be potent for inhibiting the production of NO in LPS-induced RAW264.7 cells, of which 3-(3-(4-chlorophenyl)-6-methoxy-2-(trifluoromethyl)-4H-chromen-4-yl)-1H-indole (5-25) was the most optimal (IC50 = 4.82 ± 0.34 μΜ) and was capable of significantly suppressing the release of PGE2. The inhibitory effect of 5-25 on human recombinant COX-2 (IC50 = 51.7 ± 1.3 nM) was measured and molecular docking was performed, determining 5-25 as a COX-2 inhibitor. Additionally, the interaction between 5-25 and COX-2 was determined by the CETSA technique. Then, 5-25 inhibited the degradation of IκB, the phosphorylation and nuclear translocation of NF-κB p65, and the expression of COX-2 and iNOS. Moreover, it was verified that 5-25 exhibited efficacy in rodent models of inflammation and pain, encompassing the paw edema, cotton pellet-induced granuloma, acid-induced writhing, and adjuvant-induced arthritis models. Therefore, the mechanism of 5-25 may be to bind to COX-2 and exert anti-inflammatory and analgesic effects in vitro and in vivo by suppressing the NF-κB pathway. Encouragingly, in comparison with indomethacin, 5-25 exhibited a lower ulcerative potential in rats, as manifested by generating smaller areas and fewer ulcers, less inflammatory infiltration, a lower expression of MMP-9, and less apoptosis. In conclusion, 5-25 is a candidate drug with high activity and low ulcerogenic potential, and it deserves further research for the treatment of inflammation, pain, and other symptoms in which COX-2 plays a role in their pathogenesis.

Design, classification, and adverse effects of NSAIDs: A review on recent advancements

Inflammation is a hallmark of many diseases, including cancer, neurodegenerative diseases like Alzheimer's, type II diabetes, rheumatoid arthritis, and asthma. Nonsteroidal anti-inflammatory drugs (NSAIDs) have been a cornerstone in the management of various inflammatory, pain, and fever-related conditions. As a result, NSAIDs have found their applications in new therapeutic areas. NSAIDs are known to act by inhibiting the cyclooxygenase (COX) pathway. In recent years, new strategies have been proposed to counter inflammation and develop safer COX inhibitors. This review discusses the design of new COX inhibitors, the derivatization of conventional NSAIDs, and their biological applications. The review also presents an integrated classification of NSAIDs incorporating both traditional chemical-based and function-based approaches, including a brief overview of the NSAIDs of natural origins. Additionally, the review addresses adverse effects associated with different NSAIDs, including effects associated with cardiovascular, renal, and hepatic complications emphasizing the need for the development of new and safer COX inhibitors.

The relationship of redox signaling with the risk for atherosclerosis

Oxidative balance plays a pivotal role in physiological homeostasis, and many diseases, particularly age-related conditions, are closely associated with oxidative imbalance. While the strategic role of oxidative regulation in various diseases is well-established, the specific involvement of oxidative stress in atherosclerosis remains elusive. Atherosclerosis is a chronic inflammatory disorder characterized by plaque formation within the arteries. Alterations in the oxidative status of vascular tissues are linked to the onset, progression, and outcome of atherosclerosis. This review examines the role of redox signaling in atherosclerosis, including its impact on risk factors such as dyslipidemia, hyperglycemia, inflammation, and unhealthy lifestyle, along with dysregulation, vascular homeostasis, immune system interaction, and therapeutic considerations. Understanding redox signal transduction and the regulation of redox signaling will offer valuable insights into the pathogenesis of atherosclerosis and guide the development of novel therapeutic strategies.

Syringic acid guards against indomethacin-induced gastric ulcer by alleviating inflammation, oxidative stress and apoptosis

The purpose of this study was to evaluate the effects of syringic acid, an anti-oxidant, on indomethacin induced gastric ulcers in rats. Experimental groups were control, ulcer, ulcer treated with 20 mg/kg esomeprazole (a proton pump inhibitor that reduces acid secretion), and ulcer treated with 100 mg/kg syringic acid. Rats were pretreated with esomeprazole or syringic acid two weeks before ulcer induction. Our histopathological observations showed that either syringic acid or esomeprazole attenuated the severity of gastric mucosal damage. Moreover, syringic acid and esomeprazole pretreatments alleviated indomethacin-induced damage by regulating oxidative stress, inflammatory response, the level of transforming growth factor-β (TGF-β), expressions of COX and prostaglandin E2, cell proliferation, apoptosis and regulation of the NF-κB signaling pathway. We conclude that either esomeprazole or syringic acid administration protected the gastric mucosa from harmful effects of indomethacin. Syringic acid might, therefore be a potential therapeutic agent for preventing and treating indomethacin-induced gastric damage.

Umbilical Cord Mesenchymal Stem Cell Secretome Improves Clinical Outcomes and Changes Biomarkers in Knee Osteoarthritis

(1) Background: The current treatment for osteoarthritis is ineffective due to its focus on pain relief and lack of cartilage repair. Viscosupplementation such as hyaluronic acid improves symptoms but remains unnoticed for several months. Researchers are exploring cell-based therapies such as mesenchymal stem cells secretome and mesenchymal stem cells, which can repair cartilage damage. The objective of the research is to evaluate and compare the effectiveness of the secretome derived from umbilical cord mesenchymal stem cells (UC-MSCs) with hyaluronic acid (HA). (2) Methods: An open-label clinical trial involving 30 knee osteoarthritis patients divided into two groups received UC-MSC secretome and hyaluronic acid doses. The study assessed clinical outcomes using VAS and WOMAC and measured MMP-3 and TGF-β1 levels before and after treatment. (3) Results: A study of 30 subjects found that the UC-MSC secretome group showed a decrease in pain in the OA knee compared to the HA group. The therapy was most effective after the third injection, and the group showed a decrease in the MMP-3 ratio and an increase in TGF-β1 compared to the hyaluronic acid group. (4) Conclusions: UC-MSC secretome intra-articular injections showed superior clinical improvement, biomarker changes, and no side effects compared to hyaluronic acid over a 5-week interval.

Newly Synthesized 3-Indolyl Furanoid Inhibits Matrix Metalloproteinase-9 Activity and Prevents Nonsteroidal Anti-inflammatory Drug-Induced Gastric Ulceration

Indomethacin, a known nonsteroidal anti-inflammatory drug (NSAID) induces gastric inflammation, causing degradation of the extracellular matrix by specific matrix metalloproteinases (MMPs). We investigated the antiulcer efficacy of 3-indolyl furanoids (3g and 3c, i.e., methoxy substitution at 4- and 5-positions of the indole ring, respectively), derived from indomethacin. Interestingly, 3g protected against indomethacin-induced gastropathy in vivo by inhibiting MMP-9. Our work established a chemical modification strategy for the development of safer NSAIDs. Moreover, in vitro and in silico studies confirmed that 3g inhibited MMP-9 activity with an IC₅₀ value of 50 μM by binding to the catalytic cleft of MMP-9, leading to ulcer prevention. Pharmacokinetics was presented as the mean concentration-time profile in the rat plasma, and the extraction efficiency was greater than 70%, showing a C_max of 104.48 μg/mL after 6.0 h (t_max) treatment with half-life and area under the curve being 7.0 h and 1273.8 h μg/mL, respectively, indicating the higher antiulcer potency of 3g.

Gastroprotective effect methanol extract of Caesalpinia coriaria pods against indomethacin- and ethanol-induced gastric lesions in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Caesalpinia coriaria (Jacq.) Willd is widely used as a traditional medinal plant in Mexico for protective and healing purposes and the treatment of gastrointestinal diseases.

AIM OF THE STUDY

To investigate the gastroprotective effect of extract of Caesalpinia coriaria pods against ethanol-induced and indomethacin-induced gastric lesion models, its anti-inflammatory and antioxidative activities, and its main compounds through LC-MS analysis.

MATERIALS AND METHODS

Male Wistar rats were orally administered a methanol extract obtained from the pods of C. coriaria at doses of 10, 30, 100, and 300 mg/kg prior to inducing gastric lesions with ethanol or indomethacin. Gastric mucosal lesions were evaluated by macroscopic and histopathological alterations. Determination of prostaglandin E₂ (PGE₂), alpha tumor necrosis factor (TNF-α), leukotriene B₄ (LTB₄), nitrites/nitrates, superoxide dismutase (SOD), and H₂S gastric levels were investigated. Its main compounds of the active extract through LC-MS analysis.

RESULTS

Phenolic compounds were identified as major components of methanol extract. LC-MS analysis identified 15 constituents, and the significant compounds were gallic acid, 3-O-galloylquinic acid, digalloylglucose, tetragalloylglucose, valoneic acid dilactone, pentagalloylglucose, digalloylshikimic acid, and ellagic acid. Pretreatment with the extract at doses of 100 and 300 mg/kg significantly reduced gastric ulcer lesions in both models. Compared with the reference drugs (omeprazole or ranitidine, respectively), no significant difference was found (p < 0.05). The extract's gastroprotective effect was accompanied by significant decreases in leukocyte recruitment, and gastric levels of TNF-α and LTB₄ by two to fourfold (p < 0.05). Also, gastric levels of PGE₂ gastric levels were maintained and the antioxidant enzyme activities of SOD and nitrate/nitrite in the gastric tissue were improved (p < 0.05). The LC-MS analysis indicated the presence of hydrolyzable tannins (mainly gallic acid derivatives).

CONCLUSION

The results suggest that the gastroprotective effect of the methanol extract of C. coriaria pods occurs through anti-inflammatory, antioxidant, and NO modulation properties, and gallic acid derivatives may be the main possible compounds responsible for its actions.

Computational Design, Synthesis, and Pharmacological Evaluation of Naproxen-Guaiacol Chimera for Gastro-Sparing Anti-Inflammatory Response by Selective COX2 Inhibition

The 4-allyl guaiacol is a natural phenolic molecule that has been widely studied for its antioxidant capacity against reactive-oxygen-species-mediated cellular damage. Therefore, we hypothesized that concomitant use of an antioxidant and NSAID may decrease the risk of gastrointestinal toxicity and make the therapy safer. To address the gastrointestinal toxicity of conventional NSAIDs, a new S-naproxen-4-allyl guaiacol chimera (MAS-1696) was computationally developed, chemically synthesized, and tested for anti-inflammatory effectiveness and gastrointestinal safety. The inhibitory potency of MAS-1696 tested against cyclooxygenase-2 (COX2), 15-lipoxygenase-2 (15-LOX2), and lipoxygenase-5 (5-LOX) in vitro revealed a stronger inhibition of COX2. Furthermore, the MAS-1696 chimera increased the COX selectivity index by 23% as compared to the parent compound naproxen, implying higher efficacy and gastric safety. In vivo data showed that MAS-1696 was less likely to cause gastrointestinal harm than naproxen while also exerting anti-inflammatory and analgesic effects equivalent to or superior to naproxen. In conclusion, MAS-1696 is orally active, bio-labile, and crystalline, making it a medication that may be administered orally.

Design, Synthesis, and Biological Evaluation of Dual-Target COX-2/CYP51 Inhibitors for the Treatment of Fungal Infectious Diseases

The design of novel dual-target (COX-2/CYP51) inhibitors was proposed in the study, and three series of compounds were constructed though the pathway of skeleton screening and combination; their molecular structures were synthesized and evaluated. Most of the compounds exhibited significant antifungal ability. Among them, potential compounds (10a-2, 16b-3) with excellent antifungal and anti-drug-resistant fungal ability (MIC₅₀, 0.125-2.0 μg/mL) were selected for the subsequent mechanistic study. On the one hand, these compounds could block the ergosterol biosynthesis pathway by inhibiting CYP51 and influence the internal physiological function of fungal cells, which included the increase of the ROS level, the anomaly of ΔΨ_m, and the emergence of an apoptotic state. On the other hand, these compounds also effectively showed COX-2 inhibition ability, eliminated the inflammatory reaction of the infected region, and activated the body's immune function. In summary, this study not only provided a novel antifungal drug design pathway but also discovered excellent target compounds.

Efficiency evaluation of Amlodipine combined with N-acetylcysteine on Indomethacin-induced gastritis in rats

Introduction: It is a well-known phenomenon that nonsteroidal anti-inflammatory drugs cause gastric mucosal damage. Amlodipine is a third generation dihydropyridine-type calcium channel blocker; it can inhibit inflammatory cytokines and enhance antioxidant defenses. N-acetylcysteine can act both as a precursor of reduced glutathione and as a direct ROS scavenger. Moreover, N-acetylcysteine has been purported to have anti-inflammatory properties.

Materials and methods: 34 albino Wistar rats were used. The model of gastritis was induced by subcutaneous Indomethacin prepared in 5% sodium bicarbonate administered at a dose rate of 9 mg/kg for two days at 24h intervals. N-acetylcysteine (500 mg/kg), Amlodipine (10 mg/kg) and N-acetylcysteine (500 mg/kg) combined with Amlodipine (5 mg/kg) were administrated for seven consecutive days beginning 24 h after the first Indomethacin injection. Rats were sacrificed under ether anesthesia on the 8th day. The stomach injury was assessed by macroscopic damage and histological study.

Results and discussion: The results showed that macroscopic stomach damage scores caused by administration of Indomethacin did not significantly decrease by administration of N-acetylcysteine alone (p&gt;0.05), but it decreased significantly by administration of Amlodipine alone or by its combination with N-acetylcysteine (p&lt;0.05). Microscopic stomach damage scores did not significantly decrease by administration of Amlodipine or N-acetylcysteine alone (p&gt;0.05), but they decreased significantly by administering the combination of Amlodipine with N-acetylcysteine (p&lt;0.05). Administration of Amlodipine with N-acetylcysteine showed significant reduction in the severity of the gastric inflammation induced by Indomethacin, which was evidenced macroscopically and microscopically.

Conclusion: This study concluded that administration of Amlodipine with N-acetylcysteine produce obvious enhancement in gastritis induced by Indomethacin.

Graphical abstract:

Analagesic and Anti-Inflammatory Potentials of a Less Ulcerogenic Thiadiazinethione Derivative in Animal Models: Biochemical and Histochemical Correlates

Purpose

Gastric ulcer induced by NSAIDs is the major medical concern and researchers are utilizing several approaches to combat this medical issue. In the current study, we investigated the efficacy of thiadiazinethione derivative (2,2’(2-thioxo-1,3,5-thiadiazinane-3,5-diyl) diacetic acid, as new less ulcerogenic compound.

Methods

2,2’(2-thioxo-1,3,5-thiadiazinane-3,5-diyl) diacetic acid was evaluated using standard animal models including hot plate, writhing test and formalin induced nociceptive models. Anti-inflammatory activity was assessed via carrageenan-induced paw oedema model. Involvement of opioidergic nociceptive mechanism was confirmed via naloxone administration in hot plat assay. The gastro-ulcerogenic potential of test and standard compounds were evaluated via NSAID-induced pyloric ligation model followed by standard histopathological and biochemical analysis.

Results

In acetic acid-induced writhing test, our compound significantly reduced abdominal constrictions at the tested doses of 15 (p < 0.05), 30 (p < 0.01) and 45 mg kg⁻¹ (p < 0.001) as compared to control (p < 0.001). In hot plate test, after 30 min of administration, our test compound showed significant anti-nociceptive potential (p < 0.05 at 15 and 30 mg kg⁻¹ and p < 0.01 at 45 mg kg⁻¹) and tramadol (p ˂ 0.001) at 30 mg kg⁻¹ dose. After 60 min tramadol (30 kg⁻¹) and test sample (30, 45 mg kg⁻¹) exhibited significant anti-nociceptive activity p < 0.001. In Formalin-induced nociceptive response, a significant decline (p ˂ 0.001) was observed for aspirin and test compound during acute and chronic phases. Decline in the anti-nociceptive potential of tramadol and test sample via administration of naloxone indicate the involvement of opioidergic mechanism. Our compound exhibited significant anti-inflammatory activity in second phase of carrageenan induced paw oedema model. Histological and biochemical parameters exhibited less ulcerogenic potential as compared to aspirin.

Conclusion

Our findings suggests that our test compound has desirable anti-nociceptive and anti-inflammatory potentials with less propensity to cause gastric ulcer.

Fluconazole-COX Inhibitor Hybrids: A Dual-Acting Class of Antifungal Azoles

When used in combination with azole antifungal drugs, cyclooxygenase (COX) inhibitors such as ibuprofen improve antifungal efficacy. We report the conjugation of a chiral antifungal azole pharmacophore to COX inhibitors and the evaluation of activity of 24 hybrids. Hybrids derived from ibuprofen and flurbiprofen were considerably more potent than fluconazole and comparable to voriconazole against a panel of Candida species. The potencies of hybrids composed of an S-configured azole pharmacophore were higher than those with an R-configured pharmacophore. Tolerance, defined as the ability of a subpopulation of cells to grow in the presence of the drug, to the hybrids was lower than to fluconazole and voriconazole. The hybrids were active against a mutant lacking CYP51, the target of azole drugs, indicating that these agents act via a dual mode of action. This study established that azole-COX inhibitor hybrids are a novel class of potent antifungals with clinical potential.

In Silico Approach Using Free Software to Optimize the Antiproliferative Activity and Predict the Potential Mechanism of Action of Pyrrolizine-Based Schiff Bases

In the current study, a simple in silico approach using free software was used with the experimental studies to optimize the antiproliferative activity and predict the potential mechanism of action of pyrrolizine-based Schiff bases. A compound library of 288 Schiff bases was designed based on compound 10, and a pharmacophore search was performed. Structural analysis of the top scoring hits and a docking study were used to select the best derivatives for the synthesis. Chemical synthesis and structural elucidation of compounds 16a–h were discussed. The antiproliferative activity of 16a–h was evaluated against three cancer (MCF7, A2780 and HT29, IC₅₀ = 0.01–40.50 μM) and one normal MRC5 (IC₅₀ = 1.27–24.06 μM) cell lines using the MTT assay. The results revealed the highest antiproliferative activity against MCF7 cells for 16g (IC₅₀ = 0.01 μM) with an exceptionally high selectivity index of (SI = 578). Cell cycle analysis of MCF7 cells treated with compound 16g revealed a cell cycle arrest at the G₂/M phase. In addition, compound 16g induced a dose-dependent increase in apoptotic events in MCF7 cells compared to the control. In silico target prediction of compound 16g showed six potential targets that could mediate these activities. Molecular docking analysis of compound 16g revealed high binding affinities toward COX-2, MAP P38α, EGFR, and CDK2. The results of the MD simulation revealed low RMSD values and high negative binding free energies for the two complexes formed between compound 16g with EGFR, and CDK2, while COX-2 was in the third order. These results highlighted a great potentiality for 16g to inhibit both CDK2 and EGFR. Taken together, the results mentioned above highlighted compound 16g as a potential anticancer agent.

Alpha-lipoic acid: A promising adjuvant for nonsteroidal anti-inflammatory drugs therapy with improved efficacy and gastroprotection

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in a wide variety of diseases due to their analgesic and anti-inflammatory effects, but their usage have been limited due to significant ulcerogenic side effects. In the present study, we aimed to evaluate the effect of α-lipoic acid (ALA) treatment on the anti-inflammatory activity of indomethacin (Indo) as well as the possible therapeutic effect of ALA on high dose Indo-induced gastropathy in female mice. Mice were treated with Indo (5 or 30 mg/kg, p.o) alone or in combination with ALA (50, 100 or 200 mg/kg, i.p). in vivo anti-inflammatory effect was evaluated by formalin-induced paw edema measured as paw thickness and edema. Gastric damage was evaluated macroscopically and histologically by scoring mucosal hemorrhage, erosion, edema and inflammation. To our results, Indo was ineffective at 5 mg/kg, but co-treatment with Indo and ALA significantly reduced paw edema, implying that ALA augmented the anti-inflammatory effect of subtherapeutic dose of Indo. However, ALA was not able to induce a further increase in the anti-inflammatory effect of Indo at 30 mg/kg. Unlike the treatment with Indo at 5 mg/kg, Indo at 30 mg/kg caused severe gastric damage that prevented by co-treatment with ALA. These results suggest that combination of ALA with NSAIDs can both increase anti-inflammatory effect and prevent NSAIDs-induced gastric damage. ALA would be promising adjuvant that can reduce dose for effective NSAID therapy, which improves safety profile of NSAIDs especially in cases long-term administration of high dose needed.

Hydrogen sulfide releasing molecule MZe786 inhibits soluble Flt-1 and prevents preeclampsia in a refined RUPP mouse model

An imbalance in angiogenic growth factors and poor utero-placental perfusion are strongly associated with preeclampsia. The reduced utero-placental perfusion (RUPP) model that mimics insufficient placental perfusion is used to study preeclampsia. The aim of this study was to develop a refined RUPP model in C57Bl/6 J mice to test the efficacy of MZe786 as a potential inhibitor of soluble Flt-1 for preeclampsia therapy. Murine RUPP (mRUPP) was induced through bilateral ligation of the ovarian arteries at E11.5 that resulted in typical preeclampsia symptoms including increase in mean arterial pressure (MAP), kidney injury and elevated soluble Flt-1 (sFlt-1) levels in the maternal plasma and amniotic fluid. The murine RUPP kidneys showed tubular and glomerular damage along with increased oxidative stress characterised by increased nitrotyrosine staining. The mRUPP displayed abnormal placental vascular histology, reduced expression of placental cystathionine γ-lyase (CSE), the hydrogen sulfide (H₂S) producing enzyme, and resulted in adverse fetal outcomes (FGR). Importantly, oral administration of hydrogen sulfide (H₂S)-releasing compound MZe786 from E11.5 to E17.5 successfully prevented the development of preeclampsia. Specifically, MZe786 treatment reduced maternal MAP and kidney nitrotyrosine staining and improved fetal outcome. The circulation levels of sFlt-1 were dramatically decreased in MZe786 treated animals implying that H₂S released from MZe786 offered protection by inhibiting sFlt-1 levels. MZe786 prevent preeclampsia and warrant a rapid move to randomised control clinical trial.

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Refined mouse reduced uterine perfusion pressure (mRUPP) model exhibits preeclampsia symptoms.

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Mouse RUPP induces maternal hypertension, kidney injury, elevates circulating sFlt-1 levels and promotes nitrosative stress.

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Mouse RUPP reduces expression of the protective enzyme, placental cystathionine γ-lyase and causes poor fetal outcome.

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H₂S releasing aspirin, MZe786, acts as an inhibitor of sFlt-1 to successfully prevent preeclampsia and improve fetal outcome.

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MZe786 is a novel drug with therapeutic potential to prevent preeclampsia.

Methanolic Extract of Distemonanthus benthamianus (Caesalpiniaceae) Stem Bark Suppresses Ethanol/Indomethacin-Induced Chronic Gastric Injury in Rats

Distemonanthus benthamianus (Caesalpiniaceae) is a plant from the Cameroon pharmacopoeia very widely used in the treatment of many pathologies among which are gastrointestinal disorders. The main purpose of this study was to assess the healing properties of gastric ulcer from the methanolic extract of Distemonanthus benthamianus and its mechanisms of action. The healing properties of gastric ulcers (chronic ulcer model induced by ethanol and indomethacin) were evaluated in vivo in adult male rats, while the mechanisms of action were evaluated in vitro by anti-inflammatory assay (protein denaturation, cyclooxygenase, and lipoxygenase assays) and immunomodulatory assay (ROS production (using technical chemiluminescence), cytokine (TNF-α, IL-1β, IL-6) production (using ELISA), proliferation of T cells (using liquid scintillation counter), and cytotoxicity (using MTT assay)). The methanolic extract of Distemonanthus benthamianus inhibited protein denaturation (75.63%) and the activities of cyclooxygenase (78.92%) and 5-lipoxygenase (81.54%). The extract also significantly (p < 0.001) inhibited intracellular and extracellular ROS production and T cell proliferation and reduced significantly (p < 0.01, p < 0.001) TNF-α, IL-1β, IL-6, and PGE2 production. At all doses (125, 250, and 500 mg/kg), the extract significantly reduces the ulceration index and the area of ulceration and significantly increases the mass of gastric mucus. In addition, the extract significantly decreases the level of MDA, significantly increases the activities of catalase and glutathione, and then improves the hematological parameters in sick animals. Histological micrographs show that in the presence of the extract, there is advanced reepithelialization with recovery of the ulcerated epithelium. Thus, the extract of Distemonanthus benthamianus has healing properties against gastric ulcers which are associated with its anti-inflammatory, immunomodulatory, and antioxidant effects.

Non-steroidal anti-inflammatory drugs (NSAIDs) and organ damage: A current perspective

Owing to the efficacy in reducing pain and inflammation, non-steroidal anti-inflammatory drugs (NSAIDs) are amongst the most popularly used medicines confirming their position in the WHO's Model List of Essential Medicines. With escalating musculoskeletal complications, as evident from 2016 Global Burden of Disease data, NSAID usage is evidently unavoidable. Apart from analgesic, anti-inflammatory and antipyretic efficacies, NSAIDs are further documented to offer protection against diverse critical disorders including cancer and heart attacks. However, data from multiple placebo-controlled trials and meta-analyses studies alarmingly signify the adverse effects of NSAIDs in gastrointestinal, cardiovascular, hepatic, renal, cerebral and pulmonary complications. Although extensive research has elucidated the mechanisms underlying the clinical hazards of NSAIDs, no review has extensively collated the outcomes on various multiorgan toxicities of these drugs together. In this regard, the present review provides a comprehensive insight of the existing knowledge and recent developments on NSAID-induced organ damage. It precisely encompasses the current understanding of structure, classification and mode of action of NSAIDs while reiterating on the emerging instances of NSAID drug repurposing along with pharmacophore modification aimed at safer usage of NSAIDs where toxic effects are tamed without compromising the clinical benefits. The review does not intend to vilify these 'wonder drugs'; rather provides a careful understanding of their side-effects which would be beneficial in evaluating the risk-benefit threshold while rationally using NSAIDs at safer dose and duration.

A Comprehensive Review on the Screening Models for the Pharmacological Assessment of Antiulcer Drugs

BACKGROUND

Due to inappropriate diet, smoking, alcohol consumption, regular use of drugs like NSAIDs and sedentary lifestyle, one may feel upper abdominal pain which may be the predictor of the gastrointestinal disorder called Peptic Ulcer. When an imbalance occurs between the defensive factor and aggressive factor of the stomach, ulcer formation in the esophageal lining, stomach, or duodenum takes place. This leads to the formation of small sores that cause pain. Another condition that synergizes the abdominal pain is vomiting materials which look like coffee grounds, blood in the stool, black or tarry stools. This pain may increase after lunch or dinner. This problem persists, that often leads to the gastroenterologist's consultation.

OBJECTIVE

There are many antiulcer screening models present for the determination of antiulcer activity of the drug molecule. The main objective of this study is to find which model is best for the determination of antiulcer activity.

METHODS

A literature search was conducted on the databases namely Science direct and PubMed with the help of different keywords such as "Anti-ulcer", "In-vitro models" and "In-vivo models". The search was customized by applying the appropriate filters so as to get the most relevant articles to meet the objective of this review article.

RESULT

There are different research and review papers based on the antiulcer screening models for the determination of antiulcer activity of new drug molecules.

CONCLUSION

On the basis of our study, we found some useful models for the antiulcer activity of drugs and suggested that, if we use in-vitro and in-vivo methods together, then we may obtain the most relevant result in our research area.

Evaluation of Biological Activity of Derivatives of 1,3,4-Thiadiazole, 1,3,4-Oxadiazole and 1,2,4-Triazole

OBJECTIVE

1,3,4-thiadiazole (A), 1,3,4-oxadiazole (B) and 1,2,4-triazole (C) derivatives have been known for their immense pharmacotherapeutic potential. The current research article attempts to further explore and understand the probable biochemical mechanism related to antiinflammatory activity of derivatives.

METHODS

The screened A, B and C derivatives were investigated for both in-vitro (Erythrocyte Membrane stabilization activity, Proteinase enzyme inhibitory activities) and in-vivo correlation using acute and chronic anti-inflammatory potential by carrageenan induced rats paw edema and cotton pellet granuloma methods, respectively. The activity was studied after interpreting acute toxicity studies results.

RESULTS

In vitro studies in the case of Erythrocyte Membrane stability and Proteinase enzyme inhibitory activities exhibited by A, B, and C at 100 ppm were found to be 48.89%, 51.08% and 50.08% and 66.78%, 76.91% and 57.41%, respectively. The maximum toxic dose was found to be 2000 mg/kg. The derivatives were studied for two-dose levels viz; Lower (100 mg/kg) and higher dose (200 mg/kg). In rat paw edema, maximum decrease was obtained for A (50.05%), B (50.05%) and C (51.06%) at lower and higher dose at 68.76%, 55.61%, and 65.26%, respectively for effect up to 24 h. In the chronic model of cotton pellet granuloma viz; higher and lower doses of A, B and C exhibited 38.15%, 33.19% and 30.25 % and 19.45%, 18.55% and 17.55 %, respectively.

CONCLUSION

The studied models depicted that derivatives A, B and C have the probable potential as anti-inflammatory agents. Further studies need to be undertaken to explore their potential in the different therapeutic areas.

Anti-inflammatory, antioxidant, and gaso-protective mechanism of 3α-hydroxymasticadienoic acid and diligustilide combination on indomethacin gastric damage

The co-administration of 3α-hydroxymasticadienoic acid (3α-OH MDA) and diligustilide (DLG) generates a synergist gastroprotective effect on indomethacin-induced gastric damage. However, the related protective activities of the compounds alone (or in combination) remain unclear. In the present study, we evaluated the anti-inflammatory and antioxidative activities, as well as the potential modulation of important gasotransmitters of each compound individually and in combination using the indomethacin-induced gastric damage model. Male Wistar rats were treated orally with the 3α-OH MDA, DLG, or their combination (at a fixed ratio of 1:1, 1:3, and 3:1) 30 min before the generation of gastric mucosal lesions with indomethacin (30 mg/kg, p.o.). Three hours later, the gastric injury (mm²) was determined. Results from these experiments indicate, in addition to maintaining basal levels of PGE₂, the gastroprotective effect of the pre-treatment with 3α-OH MDA (70%), DLG (81%), and their combination (72%) which was accompanied by significant decreases in leukocyte recruitment, as well as decreases in TNF-α and LTB₄ gastric levels (p < 0.05). We also found that the pre-treatment maintains the basal antioxidant enzyme activities (SOD) and gastric NO and H₂S production even in the presence of indomethacin (p < 0.05). In conclusion, when 3α-OH MDA-DLG is given at a 1:1 combination ratio, the gastroprotective effect and the inflammatory, antioxidant, and gaso-modulation properties are not different from those of treatments using the maximum doses of each compound, revealing that this combination produces promising results for the treatment of gastric ulcers.

Evaluating the mucoprotective effect of polydeoxyribonucleotide against indomethacin-induced gastropathy via the MAPK/NF-κB signaling pathway in rats

Non-steroidal anti-inflammatory drugs (NSAIDs) cause gastric mucosal damage and gastric ulceration. Among the most commonly used NSAIDs, indomethacin upregulates mucosal tumor necrosis factor-α, which activates nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinases (MAPK) to induce various pro-inflammatory mediators. Polydeoxyribonucleotide (PDRN) is an adenosine A_2A receptor agonist that exerts anti-inflammatory effects. In this study, we evaluated the efficacy of PDRN in the initial treatment of gastropathy against that of ecabet sodium and irsoglandin maleate, which are commonly used medications. The rats were administrated indomethacin once a day for 7 days after 24 h of fasting to induce gastropathy. Rats in the drug-treated groups were orally administrated 500 μl of distilled water containing the drug once daily for 7 days 1 h after indomethacin administration. Indomethacin administration caused mucosal damage and increased pro-inflammatory cytokine release. Both NF-κB and MAPK cascade factors were increased by indomethacin administration. PDRN therapy more potently suppressed the expressions of NF-κB and MAPK cascade factors compared to other drugs. The expression of cyclic adenosine-3',5'-monophosphate was also increased by PDRN treatment in the indomethacin-induced gastropathy rats. These changes led to a reduction in pro-inflammatory cytokines and apoptotic factors, which ultimately promote recovery of damaged gastric tissue. Therefore, PDRN may serve as a new therapeutic option in the initial treatment of NSAIDs-induced gastropathy.

Design, Synthesis and Pharmacological Evaluation of Gastro- Protective Anti-inflammatory Analgesic Agents based on Dual Oxidative Stress / Cyclooxygenase Inhibition

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) derived local generation of reactive oxygen species (ROS) plays a crucial role in the formation of gastric ulceration.

OBJECTIVE

Therefore, anti-inflammatory analgesics with potent antioxidant activity could be a potential therapeutic strategy for the treatment of pain and inflammatory disorders without gastrointestinal (GI) side effects.

METHODS

In an effort to develop gastroprotective analgesic and anti-inflammatory agents, a series of 2-methylamino-substituted-1H-benzo[d] imidazol-1-yl) (phenyl) methanone derivatives were synthesized and evaluated in vitro for cyclooxygenase (COX) inhibition as well as anti-oxidant potential by the FRAP assay. The compounds with significant in vitro COX-1/COX-2 inhibitory activity and antioxidant activity were further screened in vivo for their anti-inflammatory and analgesic activities. Moreover, the ulcerogenic potential of test compounds was also studied. To gain insight into the plausible mode of interaction of compounds within the active sites of COX-1 and COX-2, molecular docking simulations were performed.

RESULTS

Among the various synthesized molecules, most of the compounds showed good cyclooxygenase inhibitory activity and efficient antioxidant activity in FRAP assay. After preliminary and indicative in vitro assays, three compounds exhibited most significant antiinflammatory and analgesic activity with better gastric tolerability during their in vivo evaluation. Ligand interaction studies indicated highest dock score -43.05 of 1,2- disubstituted benzimidazole derivatives in comparison to the reference ligand -30.70. Overall studies provided us (2-((4-methoxyphenylamino) methyl) -1h-benzo [d] imidazol- 1-yl) (phenyl) methanone as a lead with potent gastro-protective anti-inflammatory and analgesic activities that can be used for future research.

CONCLUSION

From the above results, it can be concluded that designing of multifunctional molecules with COX-1/COX-2 inhibitory and anti-oxidant activities could hold a great promise for further development of GI-safer NSAIDs.

Liposome-encapsulated fish oil protein-tagged gold nanoparticles for intra-articular therapy in osteoarthritis

AIM

To provide multilayered combination therapies encompassing nanoparticles and organic peptides and to assess their efficacy in the treatment of arthritis.

MATERIALS & METHODS

Fish oil protein (FP) was isolated from fish oil glands and tagged with spherical gold nanoparticles (GNPs). Tagged GNPs were encapsulated in DPPC liposomes (FP-GNP-DPPC) and characterized.

RESULTS & CONCLUSION

FP increased the hydrophilicity of GNP, while encapsulation of FP-GNP within liposomes increased the hydrophobicity. In vitro release studies of FP-GNP-DPPC exhibited sustained release of FP in simulated synovial fluid. FP-GNP-DPPC injected into intra-articular joints of rats displayed anti-osteoarthritic effects in osteoarthritic rat model. This is the first study to report the anti-osteoarthritic activity of FP and DPPC encapsulated FP-GNP liposomes.

Efficacy and safety of a fixed-dose combination of nimesulide/pantoprazole compared to naproxen/esomeprazole for pain relief in patients with osteoarticular diseases and dyspeptic symptoms

Purpose

This study investigated the safety and efficacy of fixed-dose combination tablets of naproxen/esomeprazole magnesium and nimesulide/pantoprazole to determine if both regimens are equally suited to relieve pain in patients with osteoarticular diseases and dyspeptic symptoms.

Methods

Patients were randomly assigned to receive either nimesulide/pantoprazole (100 mg/20 mg) twice daily or naproxen/esomeprazole magnesium (500 mg/20 mg) twice daily for 14 days. The primary endpoint was defined as the mean change in modified Western Ontario and McMaster Universities Osteoarthritis Index pain subscale. Secondary endpoints were mean visual analog scale score of dyspeptic symptoms (nausea, abdominal discomfort/pain, epigastric burning, postprandial fullness), mean visual analog scale score of individual dyspeptic symptoms, and individual score of dyspeptic symptoms according to patient diary. This study is registered at ClinicalTrials.gov: NCT01670552.

Results

A total of 490 patients were enrolled and randomized, and 399 completed treatment (naproxen/esomeprazole, n=201; nimesulide/pantoprazole, n=198). The difference in mean change in the modified Western Ontario and McMaster Universities Osteoarthritis Index pain score after 7 days of treatment between the two treatment groups was 2.33 mm (95% CI, −1.22 to 5.89 mm). After 14 days of therapy, the difference was 0.45 mm (95% CI, −3.29 to 4.19 mm). The most common adverse events in the pooled group were abdominal discomfort, abdominal distention, dyspepsia, and nausea, but none of these was deemed to be clinically meaningful.

Conclusion

The present study demonstrated noninferiority of a 14-day regimen with a fixed-dose combination of nimesulide/pantoprazole compared to naproxen/esomeprazole for the treatment of osteoarticular pain.

Differential effects of selective and non-selective cyclooxygenase inhibitors on fecal microbiota in adult horses

Non-steroidal anti-inflammatory drugs (NSAIDs) are routinely used in both veterinary and human medicine. Gastrointestinal injury is a frequent adverse event associated with NSAID use and evidence suggests that NSAIDs induce gastrointestinal microbial imbalance (i.e., dysbiosis) in both animals and people. It is unknown, however, whether cyclooxygenase (COX)-2-selective NSAIDs induce dysbiosis, or if this phenomenon occurs in horses administered any class of NSAIDs. Therefore, our objectives were to determine whether the composition and diversity of the fecal microbiota of adult horses were altered by NSAID use, and whether these effects differed between non-selective and COX-2-selective NSAIDs. Twenty-five adult horses were randomly assigned to 1 of 3 groups: control (n = 5); phenylbutazone (n = 10); or, firocoxib (n = 10). Treatments were administered for 10 days. Fecal samples were collected every 5 days for 25 days. DNA was extracted from feces and the 16S rRNA gene amplified and sequenced to determine the composition of the microbiota and the inferred metagenome. While the fecal microbiota profile of the control group remained stable over time, the phenylbutazone and firocoxib groups had decreased diversity, and alteration of their microbiota profiles was most pronounced at day 10. Similarly, there were clear alterations of the inferred metagenome at day 10 compared to all other days, indicating that use of both non-selective and selective COX inhibitors resulted in temporary alterations of the fecal microbiota and inferred metagenome. Dysbiosis associated with NSAID administration is clinically relevant because dysbiosis has been associated with several important diseases of horses including abdominal pain (colic), colitis, enteric infections, and laminitis.

The non-invasive exfoliated transcriptome (exfoliome) reflects the tissue-level transcriptome in a mouse model of NSAID enteropathy

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used classes of medications in the world, yet they induce an enteropathy that is associated with high morbidity and mortality. A major limitation to better understanding the pathophysiology and diagnosis of this enteropathy is the difficulty of obtaining information about the primary site of injury, namely the distal small intestine. We investigated the utility of using mRNA from exfoliated cells in stool as a means to surveil the distal small intestine in a murine model of NSAID enteropathy. Specifically, we performed RNA-Seq on exfoliated cells found in feces and compared these data to RNA-Seq from both the small intestinal mucosa and colonic mucosa of healthy control mice or those exhibiting NSAID-induced enteropathy. Global gene expression analysis, data intersection, pathway analysis, and computational approaches including linear discriminant analysis (LDA) and sparse canonical correlation analysis (CCA) were used to assess the inter-relatedness of tissue (invasive) and stool (noninvasive) datasets. These analyses revealed that the exfoliated cell transcriptome closely mirrored the transcriptome of the small intestinal mucosa. Thus, the exfoliome may serve as a non-invasive means of detecting and monitoring NSAID enteropathy (and possibly other gastrointestinal mucosal inflammatory diseases).

Genistein-attenuated Gastric Injury on Indomethacin-induced Gastropathy in Rats

Objectives:

To investigates the mucoprotective effect of genistein on gastric injury in rats with indomethacin (IMN)-induced gastropathy.

Methods:

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.

Results:

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.

Conclusions:

Genistein attenuated IMN-induced gastropathy in rats by reducing inflammation, decreasing oxidative stress, restoring mucoprotective function, and improving gastric histopathology.

SUMMARY

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.

Biological properties of citral and its potential protective effects against cytotoxicity caused by aspirin in the IEC-6 cells

Citral, 3,7-dimethyl-2,6-octadienal, is a key component of several essential oils extracted from lemon-scented herbal plants. The present study was designed to investigate the antioxidant activities of citral and assess its possible protective effects against aspirin-induced toxicity in vitro. We used IEC-6 cells (rat small intestine epithelial cells). The antioxidant activities were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), β-carotene/linoleic acid and Ferric reducing antioxidant power (FRAP). Cytotoxicity was evaluated by cell viability, anti-oxidant enzyme activities, malondialdehyde (MDA) production and by the expression of MAPKs (Mitogen-Activated Protein Kinases) pathways. According to results, citral showed an important antioxidant activity. It inhibited the oxidation of linoleic acid, a moderate DPPH was found and it showed a Ferric reducing antioxidant potential with an EC₅₀ value of 125±28.86μg/mL. Then, the co-treatment of aspirin with citral significantly decreased the aspirin-induced cell death, and the MDA level. It modulated the superoxide dismutase (SOD) and glutathione (GSH) activities. Also, the activation of MAPKs was attenuated by citral. These findings suggest that citral can protect IEC-6 cells against aspirin-induced oxidative stress that may help to discover new chemicals out of natural antioxidant substances.

The microbiota-derived metabolite indole decreases mucosal inflammation and injury in a murine model of NSAID enteropathy

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most frequently used classes of medications in the world. Unfortunately, NSAIDs induce an enteropathy associated with high morbidity and mortality. Although the pathophysiology of this condition involves the interaction of the gut epithelium, microbiota, and NSAIDs, the precise mechanisms by which microbiota influence NSAID enteropathy are unclear. One possible mechanism is that the microbiota may attenuate the severity of disease by specific metabolite-mediated regulation of host inflammation and injury. The microbiota-derived tryptophan-metabolite indole is abundant in the healthy mammalian gut and positively influences intestinal health. We thus examined the effects of indole administration on NSAID enteropathy. Mice (n = 5 per group) were treated once daily for 7 days with an NSAID (indomethacin; 5 mg/kg), indole (20 mg/kg), indomethacin plus indole, or vehicle only (control). Outcomes compared among groups included: microscopic pathology; fecal calprotectin concentration; proportion of neutrophils in the spleen and mesenteric lymph nodes; fecal microbiota composition and diversity; small intestinal mucosal transcriptome; and, fecal tryptophan metabolites. Co-administration of indole with indomethacin: significantly reduced mucosal pathology scores, fecal calprotectin concentrations, and neutrophilic infiltration of the spleen and mesenteric lymph nodes induced by indomethacin; modulated NSAID-induced perturbation of the microbiota, fecal metabolites, and inferred metagenome; and, abrogated a pro-inflammatory gene expression profile in the small intestinal mucosa induced by indomethacin. The microbiota-derived metabolite indole attenuated multiple deleterious effects of NSAID enteropathy, including modulating inflammation mediated by innate immune responses and altering indomethacin-induced shift of the microbiota.

TNFα up-regulates COX-2 in chronic progressive nephropathy through nuclear accumulation of RelB and NF-κB2

OBJECTIVE

The pathogenesis of progressive nephropathies involves inflammatory factors. The inhibition of cyclooxygenase-2 (COX-2) can limit renal damage and inflammation. However, the mechanism of up-regulation of COX-2 in nephropathy is poorly defined.

MATERIALS AND METHODS

Here we found that tumor necrosis factor alpha (TNFα) was involved in expression of COX-2 in normal rat kidney (NRK) cell line.

RESULTS

TNFα stimulated COX-2 production in a time-dependent manner in NRK cells by inducing nuclear accumulation of RelB and nuclear factor kappa B2 (NF-κB2) and their association with COX-2 gene promoter. Depletion of IκB-inducing kinase alpha, a positive regulator of activation of p100 processing to active p52, attenuated TNFα-induced COX-2 production. Furthermore, TNFα induced COX-2 production and nuclear import in anti-thymocyte serum (ATS) nephropathy.

DISCUSSION AND CONCLUSION

These data suggest that TNFα-RelB/p52 pathway may be involved in the early stages of renal damage, in part by stimulating COX-2 and inflammatory responses.

Risks associated with drug treatments for kidney stones

INTRODUCTION

Renal stones are one of the most painful medical conditions patients experience. For many they are also a recurrent problem. Fortunately, there are a number of drug therapies available to treat symptoms as well as prevent future stone formation.

AREAS COVERED

Herein, we review the most common drugs used in the treatment of renal stones, explaining the mechanism of action and potential side effects. Search of the Medline databases and relevant textbooks was conducted to obtain the relevant information. Further details were sourced from drug prescribing manuals. Recent studies of drug effectiveness are included as appropriate.

EXPERT OPINION

Recent controversies include medical expulsive therapy trials and complex role of urinary citrate in stone disease. Future directions in research will involve new medical therapies for stone prevention, for example new drugs for hyperoxaluria.

Protective activity of crocin against indomethacin-induced gastric lesions in rats

The present study was designed to elucidate the mechanism(s) of the gastro-protective effect of crocin against indomethacin-induced gastric lesions. Crocin or pantoprazole was administered to rats 30 min before indomethacin. Five hours later, the animals were killed and their stomachs were removed and examined macroscopically. Samples of gastric mucosa were collected for microscopic evaluation, mRNA expression of caspase-3, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 was quantified by RT-PCR, and protein levels of COX-1, COX-2, iNOS and caspase-3 were assessed by Western blotting. The pH, volume of gastric effluent and antioxidant activity were measured in 5 separate groups of rats following pylorus ligation. Indomethacin induced significant increases in mRNA and protein expression of iNOS and caspase-3 and increased MDA levels, and reduced the pH of the gastric effluent and protein and mRNA expression of COX-2 and protein expression of COX-1 and mucus content associated with gastric ulceration. Crocin and pantoprazole significantly inhibited mRNA and protein expression of iNOS, caspase-3 and MDA, and reduced mucus content induced by indomethacin. However, unlike pantoprazole, crocin failed to increase COX-1 and pH, but had variable increasing effects on mRNA and protein expression of COX-2. Macroscopic and microscopic observations showed that mucosal erosions induced by indomethacin were significantly inhibited by pantoprazole and crocin. These findings suggest that crocin exerts its gastro-protective effects mainly by inhibition of MDA, reduction in iNOS and caspase-3, and inhibition of the reduction in mucus content induced by indomethacin. Crocin is a novel agent that has potential in the prevention of ulceration induced by NSAIDs.

Benzimidazole derivatives: search for GI-friendly anti-inflammatory analgesic agents

Non-steroidal anti-inflammatory drugs (NSAIDs) have been successfully used for the alleviation of pain and inflammation in the past and continue to be used daily by millions of patients worldwide. However, gastrointestinal (GI) toxicity associated with NSAIDs is an important medical and socioeconomic problem. Local generation of various reactive oxygen species plays a significant role in the formation of gastric ulceration associated with NSAIDs therapy. Co-medication of antioxidants along with NSAIDs has been found to be beneficial in the prevention of GI injury. This paper describes the synthesis and biological evaluation of N-1-(phenylsulfonyl)-2-methylamino-substituted-1H-benzimidazole derivatives as anti-inflammatory analgesic agents with lower GI toxicity. Studies in vitro and in vivo demonstrated that the antioxidant activity of the test compounds decreased GI toxicity.

Epithelial MUC1 promotes cell migration, reduces apoptosis and affects levels of mucosal modulators during acetylsalicylic acid (aspirin)-induced gastropathy

MUC1 is a transmembrane mucin highly expressed in the stomach. Although extensive research has uncovered many of its roles in cancer, knowledge about the functions of MUC1 in normal tissues is limited. In the present study, we showed that acetylsalicylic acid (ASA; aspirin) up-regulated MUC1/Muc1 expression in the gastric mucosa of humans and wild-type (WT) mice. ASA induced mucosal injury in all mice to a similar extent; however, WT animals and those chimaeras with Muc1 on the epithelia recovered faster than Muc1-knockout (KO) mice and chimaeras carrying Muc1 on haemopoietic but not epithelial cells. MUC1 enhanced proliferation and migration of the human gastric cell line MKN-7 and increased resistance to apoptosis. The repeated treatment regime used caused a reduction in cyclo-oxygenase-1 (Cox-1) expression, though WT animals returned faster towards pre-treatment levels and had increased Cox-2 and vascular endothelial growth factor levels during recovery. Thus we found that epithelial Muc1 is more important for the healing process than haemopoietic Muc1 and Muc1/MUC1 facilitates wound healing by enhancing cell migration and proliferation, protecting against apoptosis and mediating expression of mucosal modulators. Thus MUC1 plays essential roles during wound healing and development of treatment modalities targeting enhanced expression of MUC1 may be beneficial to treat mucosal wounds.

Morin protects gastric mucosa from nonsteroidal anti-inflammatory drug, indomethacin induced inflammatory damage and apoptosis by modulating NF-κB pathway

BACKGROUND

Deregulation in prostaglandin (PG) biosynthesis, severe oxidative stress, inflammation and apoptosis contribute to the pathogenesis of nonsteroidal anti-inflammatory drug (NSAID)-induced gastropathy. Unfortunately, most of the prescribed anti-ulcer drugs generate various side effects. In this scenario, we could consider morin as a safe herbal potential agent against IND-gastropathy and rationalize its action systematically.

METHODS

Rats were pretreated with morin for 30 min followed by IND (48 mgkg(-1)) administration for 4 h. The anti-ulcerogenic nature of morin was assessed by morphological and histological analysis. Its effects on the inflammatory (MPO, cytokines, adhesion molecules), ulcer-healing (COXs, PGE(2)), and signaling parameters (NF-κB and apoptotic signaling) were assessed by biochemical, RP-HPLC, immunoblots, IHC, RT-PCR, and ELISA at the time points of their maximal changes due to IND administration.

RESULTS

IND induced NF-κB and apoptotic signaling in rat's gastric mucosa. These increased proinflammatory responses, but reduced the antioxidant enzymes and other protective factors. Morin reversed all the adverse effects to prevent IND-induced gastric ulceration in a PGE2 independent manner. Also, it did not affect the absorption and/or primary pharmacological activity of IND.

CONCLUSIONS

The gastroprotective action of morin is primarily attributed to its potent antioxidant nature that also helps in controlling several IND-induced inflammatory responses.

GENERAL SIGNIFICANCE

For the first time, the study reveals a mechanistic basis of morin mediated protective action against IND-induced gastropathy. As morin is a naturally abundant safe antioxidant, future detailed pharmacokinetic and pharmacodynamic studies are expected to establish it as a gastroprotective agent.

Aloe vera attenuated gastric injury on indomethacin-induced gastropathy in rats

AIM: To evaluate the protective effects of Aloe vera on gastric injury in rats with indomethacin (IMN)-induced gastropathy.

METHODS: Male Sprague-Dawley rats were randomly divided into three groups. Group 1 (control, n = 6) was given distilled water (DW) orally. Group 2 (IMN, n = 6) was given oral IMN (150 mg/kg) dissolved in 5% sodium bicarbonate (NaHCO₃^-) at time 0 and 4 h. Group 3 (Aloe vera-treated, n = 6) was given oral Aloe vera (150 mg/kg) dissolved in DW and IMN at time 0 and 4 h. Eight hours later, the stomach was removed to determine gastric malondialdehyde (MDA), the number of interleukin (IL)-18 positive stained cells (%) by immunohistochemistry, and for histopathological examination. Then, the serum was collected to determine tumor necrosis factor (TNF)-α and cytokine-induced neutrophil chemoattractant (CINC)-1 by sandwich enzyme linked immunosorbent assay method.

RESULTS: In the IMN group, serum TNF-α, CINC-1 and gastric MDA were significantly increased when compared to the control group (27.78 ± 1.52 pg/mL vs 85.07 ± 49.11 pg/mL, P = 0.009; 104.55 ± 45.80 pg/mL vs 1054.70 ± 20.38 pg/mL, and 1.74 ± 0.21 nmol/mg vs 9.36 ± 1.07 nmol/mg protein, P = 0.000, respectively). The mean level of TNF-α, CINC-1 and gastric MDA in the Aloe vera-treated group were improved as compared with the IMN group (85.07 ± 49.11 pg/mL vs 35.19 ± 1.61 pg/mL, P = 0.021; 1054.70 ± 20.38 pg/mL vs 813.56 ± 239.04 pg/mL, P = 0.025; and 9.36 ± 1.07 nmol/mg vs 2.67 ± 0.64 nmol/mg protein, P = 0.000, respectively). The number of IL-18 positive stained cells (%) in the gastric epithelial cells of the IMN group was significantly higher than the control group (5.01% ± 3.73% vs 30.67% ± 2.03%, P = 0.000, respectively). In contrast, Aloe vera treatment decreased the number of IL-18 positive stained cells (%) significantly when compared with the IMN group (30.67% ± 2.03% vs 13.21% ± 1.10%, P = 0.000, respectively). Most rats in the IMN group developed moderate to severe gastric inflammation and erosions. The gastric erosions and neutrophil infiltration scores were significantly reduced in the Aloe vera-treated group.

CONCLUSION: Aloe vera attenuated IMN-induced gastropathy in rats by the reduction of oxidative stress, inflammation, and improvement of gastric histopathology.

Substrate-selective COX-2 inhibition as a novel strategy for therapeutic endocannabinoid augmentation

Pharmacologic augmentation of endogenous cannabinoid (eCB) signaling is an emerging therapeutic approach for the treatment of a broad range of pathophysiological conditions. Thus far, pharmacological approaches have focused on inhibition of the canonical eCB inactivation pathways - fatty acid amide hydrolase (FAAH) for anandamide and monoacylglycerol lipase (MAGL) for 2-arachidonoylglycerol. We review here the experimental evidence that cyclooxygenase-2 (COX-2)-mediated eCB oxygenation represents a third mechanism for terminating eCB action at cannabinoid receptors. We describe the development, molecular mechanisms, and in vivo validation of 'substrate-selective' COX-2 inhibitors (SSCIs) that prevent eCB inactivation by COX-2 without affecting prostaglandin (PG) generation from arachidonic acid (AA). Lastly, we review recent data on the potential therapeutic applications of SSCIs with a focus on neuropsychiatric disorders.

Amelioration of aspirin induced oxidative impairment and apoptotic cell death by a novel antioxidant protein molecule isolated from the herb Phyllanthus niruri

Aspirin has been used for a long time as an analgesic and anti-pyretic drug. Limitations of its use, however, remain for the gastro-intestinal side effects and erosions. Although the role of aspirin on gastro-intestinal injury has been extensively studied, the molecular mechanisms underlying aspirin-induced liver and spleen pathophysiology are poorly defined. The present study has been conducted to investigate whether phyllanthus niruri protein (PNP) possesses any protective role against aspirin mediated liver and spleen tissue toxicity, and if so, what signaling pathways it utilizes to convey its protective action. Aspirin administration in mice enhanced serum marker (ALP) levels, reactive oxygen species (ROS) generation, reduced antioxidant power and altered oxidative stress related biochemical parameters in liver and spleen tissues. Moreover, we observed that aspirin intoxication activated both the extrinsic and intrinsic apoptotic pathways, as well as down regulated NF-κB activation and the phosphorylation of p38 and JNK MAPKs. Histological assessments and TUNEL assay also supported that aspirin induced tissue damages are apoptotic in nature. PNP treatment after aspirin exposure effectively neutralizes all these abnormalities via the activation of survival PI3k/Akt pathways. Combining all results suggest that PNP could be a potential protective agent to protect liver and spleen from the detrimental effects of aspirin.