Effects of food intake and oxidative stress on intestinal lesions caused by meloxicam and piroxicam in rats

Phototoxic action of meloxicam contributes to dysregulation of redox homeostasis in normal human skin cells - Molecular and biochemical analysis of antioxidant enzymes in melanocytes and fibroblasts

The phototoxic effect of meloxicam (MLX) raises the question of the effect of the drug on the redox homeostasis of normal human skin cells. The main objective of the study was to analyze the effect of MLX and/or UVA radiation (UVAR) on the redox homeostasis of human normal skin cells - melanocytes and fibroblasts. MLX was found to affect the activity and expression of enzymes of the antioxidant system differently depending on the cell line used. The drug decreased the activity and expression of superoxide dismutase type 1 and 2 (SOD1 and SOD2), catalase (CAT) and glutathione peroxidase (GPx) in fibroblasts, while increasing the activity of these enzymes in melanocytes. UVA radiation enhanced the effects of the drug. In conclusion, MLX in combination with UVAR induces oxidative stress in melanocytes and fibroblasts, however, the analyses showed that the drug's effect the activity and expression of SOD, CAT and GPx differently, depending on the cell line. The observed dissimilarity between tested cell lines may result from the presence of melanin pigments.

Evaluation of the anti-arthritic activity of Rhuflex-F - A proprietary Ayurvedic herbomineral formulation in albino rats

Background

Rhuflex-F is a proprietary Ayurvedic herbo-mineral formulation clinically used to combat and relieve stiffness in joints and muscles, reduce edema, restore mobility, and also effective in relieving the symptoms of other autoimmune illnesses that lead to rheumatism.

Aims

The aim and objective of the research study is to evaluate the efficacy of Rhuflex-F against in vitro protein denaturation and in vivo Freund's adjuvant-induced arthritis in albino rats.

Materials and methods

In vitro inhibition of protein denaturation activity was carried out using bovine serum albumin. For in vivo activity, arthritis was induced by complete Freund's adjuvant in albino rats. Rhuflex-F (135-270 mg/kg, po) was administered for 30th days in arthritic rats, and effects were assessed on primary and secondary paw edema, on pain response, hematological, serum biochemical parameters (serum transaminases, alkaline phosphatase, urea, uric acid, and orosomucoid), and serum anti-oxidant parameters and adrenal ascorbic acid.

Results

Aqueous extract of Rhuflex-F showed in vitro protein denaturation inhibitory activity in a dose-dependent manner. Rhuflex-F showed nonsignificant decrease in primary and secondary paw edema with reduced pain response, some reversal effects on hematological parameters such as white blood cell and red blood cell related parameters and serum orosomucoid and adrenal ascorbic acid in comparison to Fruend's adjuvant control group. Further, Rhuflex-F reversed Freund's adjuvant-induced adverse effects on oxidant status in the serum of albino rats.

Conclusion

Result of the present study suggested that Rhuflex-F formulation has anti-inflammatory activity, may be due to the inhibition of protein denaturation in vitro and in vivo anti-arthritic activity against complete Freund's adjuvant-induced arthritis in albino rats.

Coenzyme Q10 supplementation mitigates piroxicam-induced oxidative injury and apoptotic pathways in the stomach, liver, and kidney

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PM produced oxidative stress in gastric, liver, and kidney tissue.

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PM-induced toxicity was mediated by ROS and mitochondrial dysfunction.

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PM enhanced the activated caspase-3 expression.

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CoQ10 alleviates PM-induced gastropathy and hepato-renal damage.

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CoQ10 might be effective in COVID-19 treatment regimen.

Piroxicam (PM) is an oxicam-NSAID commonly recommended for various pain and associated inflammatory disorders. However, it is reported to have a gastric and hepato-renal toxic effect. Therefore, the current research was planned to investigate the possible mechanisms behind the mitigating action of the coenzyme (CoQ10), a natural, free radical scavenger, against PM tissue injury. Rats were assigned to five equal groups; Control, CoQ10 (10 mg/kg, orally), PM (7 mg/kg, i.p.), CoQ + PM L, and CoQ + PM H group. After 28 days, PM provoked severe gastric ulceration and marked liver and kidney damage indicated by an elevated gastric ulcer index and considerable alteration in liver and kidney biochemical tests. The toxic effects might be attributed to mitochondrial dysfunction and excess generation of reactive oxygen species (ROS), as indicated by enhanced malondialdehyde (MDA) levels along with decreased reduced-glutathione (GSH) levels and catalase (CAT) activity. Apoptotic cell death also was demonstrated by increased regulation of activated caspase-3 in the stomach, liver, and kidney tissues. Interestingly, external supplementation of CoQ10 attenuated the PM-inflicted deleterious oxidative harm and apoptosis. This ameliorative action was ascribed to the free radical scavenging activity of CoQ10.

Cadmium overload modulates piroxicam-regulated oxidative damage and apoptotic pathways

Cadmium (Cd) is a common environmental pollutant that threatens humans' and animals' health. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used drugs due to their wide therapeutic action; however, they have significant side effects. Since, under many circumstances, humans and animals may be co-exposed to Cd and NSAIDs, the current investigation was assigned to explore the intertwining relationship between Cd and NSAIDs. Four groups of male Wister rats were used: control group: rats received saline; Cd group: rats received cadmium (Cd, 2 mg/kg) orally; Px group: rats received a NSAID (piroxicam, Px, 7 mg/kg, i.p.); and Cd+Px group: rats received both Cd+Px. All treatments were given once a day for 28 consecutive days. Then, blood samples, stomach, liver, and kidney tissues were collected. The results indicated that Px provoked gastric ulcer indicated by high ulcer index, while Cd had no effect on the gastric mucosa. In addition, treatment with Cd or Px alone significantly induced liver and kidney injuries indicated by serum elevations of AST, ALT, ALP, ALB, total protein, creatinine, and urea along with histopathological alterations. Significant increases in malondialdehyde and reduction in GSH and CAT contents were reported along with up-regulated expression of Bax and Bcl-2 after Cd or Px exposure. However, when Cd and Px were given in a combination, Cd obviously potentiated the Px-inflicted cellular injury and death in the liver and kidney but not in the stomach when compared to their individual exposure. This study concluded that oxidative stress mechanisms were supposed to be the main modulator in promoting Cd and Px toxicities when given in combination.

Evaluation of the reproductive toxicity of naproxen sodium and meloxicam in male rats

Nonsteroidal anti-inflammatory drugs that are cyclooxygenase (COX) enzyme inhibitors have generally been used in short-term pain management and also to treat inflammation chronically. It is known that COX enzyme and prostaglandins play important roles in the regulation of reproductive functions in females. However, there are relatively few studies for the male reproductive system, and the results of these studies are contradictory. In this study, sperm count and motility, COX-1, COX-2, prostaglandin E1 (PGE1), prostaglandin E2 (PGE2), and prostaglandin F2α (PGF2α) levels in testis tissue, plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels, and histopathological examination of testis tissue were evaluated after naproxen sodium and meloxicam administration in male rats. Also, testis superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione (GSH) levels were measured to investigate the oxidation status. According to our results, sperm count and motility were significantly decreased in treatment groups. Plasma hormone levels did not show any statistical differences between the groups. COX-1, PGE2, and PGF2α levels were significantly decreased, while the decreases in COX-2 and PGE1 levels did not show any significance statistically. Testis SOD, catalase, GPx, and GSH levels were decreased significantly. According to the results of histopathological examination, damage in seminiferous tubules, where spermatogenesis developed, was observed. In conclusion, naproxen sodium and meloxicam decreased the sperm count and motility and also induced the damage of seminiferous tubules as a direct effect without affecting plasma hormone levels in our study. The mechanism of the reproductive toxicity induced by these agents may be based on the inhibition of prostaglandin synthesis and the induction of oxidative stress can be emphasized as a secondary factor.

Ameliorative effect of ocimum sanctum on meloxicam induced toxicity in wistar rats

An ameliorating effect of Ocimum sanctum on the toxic effect of meloxicam, a new non-steroidal anti-inflammatory drug was studied by evaluating haemato-biochemical parameters, oxidative stress, gross and histopathological changes in various organs of Wistar rats. A total of thirty-six male rats were divided in six experimental groups each comprising of six rats and numbered from G₁ to G₆. Meloxicam toxicity was induced by oral feeding of meloxicam at 1.2 mg/kg and 2.4 mg/kg body weight in G₂ and G₃ respectively for 28 days. Group G₄ and G₅ were fed with 1.2-mg/kg body weight and 2.4-mg/kg body weight of meloxicam along with 200 mg/kg body weight of aqueous extract of Ocimum sanctum. Group G₁ serve as control while group G₆ was kept as treatment control and fed only aqueous extract of Ocimum sanctum at 200 mg/kg body weight. Clinical finding showed mild diarrhea from 23^rd day onwards in-group treated with 2.4-mg/kg body of meloxicam. Significant reduction of hemoglobin and packed cell volume (PCV) was observed in both the group treated with 1.2 mg/kg and 2.4-mg/kg body wt. of meloxicam. Ocimum sanctum could restore the hemoglobin and PCV value in-group treated with meloxicam at low dose level. Serum alkaline phosphatase, serum glutamic pyruvic transaminase, Serum glutamic oxaloacetic transaminase and total bilirubin were found elevated in meloxicam treated groups and indicated hepatotoxic activity of meloxicam. Ocimum sanctum could reduce hepatotoxic activity of meloxicam in group G4 receiving meloxicam at lower dose rate along with Ocimum sanctum failed to regulate creatinine level in meloxicam treated groups. In meloxicam toxicity elevated Lipid peroxidation values was noticed in liver and kidneys, while superoxide dismutase and glutathione did not revealed any change. Stomach and intestine revealed hemorrhagic gastroenteritis and ulcers. Perivascular necrosis with infiltration with inflammatory cells was evident in liver. Interstitial nephritis, myocardial necrosis and spongiform encephalopathy were important lesions. The Ocimum sanctum could only counteract the toxic effect of meloxicam in liver and gastrointestinal tract.

Metabolism of Non-steroidal Anti-inflammatory Drugs by Peroxidase: Implication for Gastrointestinal Mucosal Lesions

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat inflammatory diseases including rheumatoid arthritis and gout. The anti-inflammatory action of NSAIDs is due to the inhibition of prostaglandin synthesis by preventing cyclooxygenase (COX) activity of prostaglandin H synthase (PGS). However, administration of NSAIDs causes gastrointestinal mucosal lesions and a decrease of granulocytes as side effects. PGS catalyzes two distinct enzyme reactions: (1) bis-dioxygenation of arachidonic acid catalyzed by COX activity of PGS to form PGG(2); and (2) reduction of the hydroperoxide group in PGG(2) by PGS hydroperoxidase. Most NSAID are oxidized by peroxidases to produce NSAID radicals that damage biological components such as lipids and enzymes. Indomethacin, phenylbutazone, and piroxicam are more toxic under aerobic conditions than anaerobic conditions during the interaction with peroxidase. We discuss the contribution of peroxidases in the formation of gastrointestinal mucosal lesions induced by NSAIDs.

Modulation of indomethacin-induced gastric injury by spermine and taurine in rats

This study investigated the involvement of neutrophil infiltration, nitric oxide (NO) generation, and oxidative stress in indomethacin-induced ulcer and the possible gastroprotective potentials of spermine and taurine, known for their tissue regenerating and antioxidant effects, respectively. Male Wistar albino rats (180-220 g) were allocated into a normal control group, ulcer control group (received a single dose of indomethacin 40 mg-kg p.o.), and two ulcer groups pretreated with spermine (150 mg-kg p.o. 1 h before ulcer induction) and taurine (250 mg-kg i.p. for three consecutive days before ulcer induction). The animals were killed 6 h after indomethacin administration, and the gastric juice, serum, and mucosal tissue were used for gastric injury evaluation. Both modulators significantly ameliorated the indomethacin-induced gastric lesions in glandular mucosa. Notably, spermine exhibited the most pronounced effect as manifested by great reduction in the gastric ulcer index, normalization of the elevated gastric acidity, and triggering of mucin production. Spermine and taurine were able to decrease the elevated levels of gastric myeloperoxidase, conjugated diene, and serum NO. However, the lowered tissue NO content was markedly elevated only by taurine. The antioxidant action of taurine was illustrated by restoration of the depressed content of glutathione, normalization of the inhibited activities of glutathione reductase, and superoxide dismutase. These results suggest that spermine and taurine confer significant gastroprotection against indomethacin-induced gastric injury with the priority of spermine.

Pathological quantification of experimental gastric ulcer in mice

AIM: To develop a method of quantifying the pathological changes gastric ulcer in the experimental mice.

METHODS: The experimental mice were fed with alcohol to establish the model of gastric ulcer. The area of the ulcer was quantified by weight and picture integration. Then the ratio of ulcer area to total stomach area (ulcer area ratio, UAR) was calculated to assess the degrees of the ulcers on the stomach wall. Furthermore, the methods of weighing, picture integration, marking, and grading were compared.

RESULTS: The mark indexes and the UAR by weight and picture integration were significantly different between different grading groups (Grade 4 vs Grade 2 vs Grade 1: 84.0±27.8 vs 19.6±8.1 vs 4.0±1.0, P<0.05; 40.74±0.26% vs 4.22±0.01%vs 1.03±0.01%, P<0.05; 31.57 ±0.16% vs 4.36±0.02% vs 2.43±0.02%, P<0.05) respectively, but the petechiae have no significant difference (P>0.05). Except in one mouse, the differences of UAR between by weight and picture integration in other five mice were 0.69, 4.89, 7.41, 1.26 and 2.76 respectively, which showed UAR had no marked difference between the two methods. In comparison of model I with model II, there were no obvious differences in the mark indexes, grading indexes and the numbers of petechiae while the UARs between by weight and picture integration were significantly different (6.14±0.08%vs 27.64±0.31%, P<0.05; 6.56±0.07% vs 21.22±0.21%, P<0.05).

CONCLUSION: The degrees of the gastric ulcer can be accessed by weight, picture integration, marking and grading. Weighing is better for measuring the ulcer over the fourth grade while picture integration can be used in all the degrees. The sensitivity and accuracy of picture integration and weighing are higher than those of traditional marking and grading.

Mechanisms underlying intestinal injury induced by anti-inflammatory COX inhibitors

By far the most attention has been paid to the deleterious actions of nonsteroidal anti-inflammatory drugs (NSAIDs), including isoform selective agents that inhibit cyclooxygenase (COX), on the upper gastrointestinal tract, particularly the gastric and duodenal mucosa. However, recent studies confirm a relatively high incidence of serious clinical events, especially with the more-established drugs of this class, involving the small intestine. Pathogenic factors that have been proposed from early studies in such enteropathy have included the enterohepatic circulation of the nonsteroidal anti-inflammatory drugs, inhibition of cyclooxygenase, surface epithelial changes and focal microvascular events. More recent work has concerned the role of infiltrating inflammatory cells, the relative roles of cyclooxygenase isoforms, COX-1 and COX-2 and the key involvement of inducible nitric oxide (NO) synthase and its product in combination with superoxide, peroxynitrite. In the present review, evidence for the underlying involvement of each these processes, and their sequential integration in the development of the intestinal injury and ulceration promoted by nonsteroidal anti-inflammatory drugs has been considered.

Mucosal damage induced by preferential COX-1 and COX-2 inhibitors: role of prostaglandins and inflammatory response

Nonsteroidal anti-inflammatory drugs (NSAID) are well known to induce gastric mucosal damage including bleeding, ulceration and perforation in humans and animals too. These effects are related with the inhibition of the enzyme cyclooxygenase, which is the main established mechanism of action for these drugs. Fasted rats were given piroxicam, preferential COX-1 inhibitor (10-20 mg/kg) or meloxicam, preferential COX-2 inhibitor (7.5-15 mg/kg) orally. Six or nine hours (h) later, respectively, the stomach was excised, the severity of the damage assessed and myeloperoxidase (MPO) activity measured, as well as prostaglandin PGE(2) content. Furthermore, in order to assess the effects of these oxicams over previously damaged gastric mucosa, 1 ml of 0.6 N HCl was administered p.o. followed, 1 h after, of the correspondent dose of each NSAID, and the same parameters were determined. Oral administration of both drugs dose-dependently caused acute gastric haemorrhage erosions. Myeloperoxidase activity was significantly increased by piroxicam administration. In addition, PGE(2) content was significantly reduced. The association between the administration of the acid and NSAID caused a worsening of the damage and, while myeloperoxidase activity did not modify by both piroxicam and meloxicam, PGE(2) levels were reduced. These results suggest that the PG derived from both COX-1 and COX-2 pathway plays a beneficial role in the gastroprotection, and thus caution should be exercise in the clinical use of preferential COX-2 inhibitors.