Modulation of Enzyme-Catalyzed Synthesis of Prostaglandins by Components Contained in Kidney Microsomal Preparations

In the kidney, prostaglandins formed by cyclooxygenase 1 and 2 (COX-1 and COX-2) play an important role in regulating renal blood flow. In the present study, we report our observations regarding a unique modulatory effect of renal microsomal preparation on COX-1/2-mediated formation of major prostaglandin (PG) products in vitro. We found that microsomes prepared from pig and rat kidneys had a dual stimulatory–inhibitory effect on the formation of certain PG products catalyzed by COX-1 and COX-2. At lower concentrations, kidney microsomes stimulated the formation of certain PG products, whereas at higher concentrations, their presence inhibited the formation. Presence of kidney microsomes consistently increased the Km values of the COX-1/2-mediated reactions, while the Vmax might be increased or decreased depending on stimulation or inhibition observed. Experimental evidence was presented to show that a protein component present in the pig kidney microsomes was primarily responsible for the activation of the enzyme-catalyzed arachidonic acid metabolism leading to the formation of certain PG products.

Cnicin from Centaurea benedicta L. is an active compound against skin inflammation in a mouse model

Centaurea benedicta L., commonly known as “cardo santo,” is used as a tonic, antidepressant, anti-inflammatory, antibacterial, and antiseptic in traditional medicine. This study evaluated the topical anti-inflammatory potential of an extract (ECB) and cnicin (CNI) from C. benedicta leaves in a mouse model. Activity was assessed using the ear edema method with croton oil, phenol, capsaicin, and histamine as phlogistic agents. Myeloperoxidase (MPO), N-acetyl-β-D-glucosaminidase (NAG), nitric oxide (NO), t umor necrosis factor α (TNF-α), interleukin 6 (IL-6), and histopathology were assessed as markers of edema/inflammation. Interaction profiles between CNI and cyclooxygenase-1 and -2, induced nitric oxide synthase, and glucocorticoid receptor were examined with molecular docking. Twenty-four h after induction of inflammation, ECB and CNI treatments decreased the thickness and weight of ears by 39.59%– 94.72%. MPO, NAG, NO, TNF-α, and IL-6 levels were also reduced. Histopathological, treatments reduced edema thickness, leukocytes, and vasodilation. Inflammation induced by phenol and histamine was inhibited by ECB and CNI, and ECB suppressed capsaicin-induced inflammation. CNI interacts with cyclooxygenase-1 and nitric oxide synthase through conventional hydrogen bonds, indicating inhibition of these enzymes. ECB and its compound cnicin reduce chemically-induced inflammation in mice suggesting new possibilities for the treatment of diseases associated with dermal inflammatory processes.

Meloxicam in pain syndrome treatment of comorbid diseases patients

The issue nonsteroidal anti-inflammatory drugs (NSAIDs) use safety is associated with a high frequency of adverse events (AEs) from the gastrointestinal tract and cardiovascular risks. Patients with lower back pain (LBP) and osteoarthritis (OA), as a rule, have comorbid diseases, such as arterial hypertension (AH), coronary heart disease (CHD), gastrointestinal tract (GIT) diseases, which significantly complicates the appointment of NSAIDs. The main guideline in NSAIDs appointment is the selective ability to inhibit cyclooxygenase-1 and -2 (COX). The ratio of the activity of NSAIDs when blocking COX-1/COX-2 allows us to judge their potential toxicity. And, then higher the selectivity of NSAIDs, then lower its toxicity. For example, the ratio of COX-1/COX-2 in meloxicam is 0.33, diclofenac – 2.2, tenoxicam – 15, piroxicam – 33, indomethacin – 107. To the predominantly selective COX-2 NSAIDs include meloxicam, which has little effect on the GIT, the lowest relative risk (RR) of complications from the cardiovascular system (CVS). The therapeutic efficacy of meloxicam is comparable to piroxicam and diclofenac. A number of studies have shown the high efficacy of meloxicam, both with per oral (p/o) administration (7.5–15 mg/d), and with intramuscular (i/m) administration (1.5 ml), and when injected into trigger zones. Both with p/o and the injectable form of meloxicam has minimal GIT AEs and absence local reaction in the injection area. The drug can be recommended both as a combination therapy and prescribed in monotherapy.

10 Pharmacodynamic profiles of aspirin versus dual-pathway inhibition with either aspirin or clopidogrel among patients with stable atherosclerotic disease

Aims Inhibition of thrombin-mediated signalling processes using a vascular dose of rivaroxaban in adjunct to single antiplatelet therapy, known as dual-pathway inhibition (DPI), reduces atherothrombotic events in patients with stable atherosclerotic disease. However, there is limited data on the pharmacodynamic (PD) effects of this strategy. Methods This investigation was conducted in selected cohorts of patients (n = 40) with stable atherosclerotic disease enrolled from a larger prospective, open-label, parallel-group PD study who were treated with either aspirin, aspirin plus rivaroxaban 2.5 mg/bid or clopidogrel plus rivaroxaban 2.5 mg/bid. Multiple PD assays providing a comprehensive assessment of markers of thrombosis were used. The primary endpoint was the comparison between groups of platelet-mediated global thrombogenicity by light transmittance aggregometry (LTA) following stimuli with collagen-related peptide + adenosine diphosphate + tissue factor (CATF). Results There were no differences in the primary endpoint between aspirin vs. aspirin plus rivaroxaban 2.5 mg/bid (P = 0.110), aspirin vs. clopidogrel plus rivaroxaban 2.5 mg/bid (P = 0.611) or aspirin plus rivaroxaban 2.5 mg/bid vs. clopidogrel plus rivaroxaban 2.5 mg/bid (P = 0.315). Rivaroxaban-based treatments significantly reduced markers of thrombin generation (peak thrombin and thrombin velocity index). Clopidogrel-based treatments reduced markers of P2Y12 signalling (LTA ADP 20 max and VerifyNow). Aspirin-based treatments reduced markers of markers of cyclooxygenase-1 activity (LTA collagen). Conclusions Compared with aspirin alone, DPI with either aspirin or clopidogrel might provide superior ischaemic protection by targeting pathways alternative to those affected by antiplatelet agents with only a moderate trade-off in bleeding as supported by similar platelet-mediated global thrombogenicity between treatments.

Gastroprotective Effect of Myricetin on Ethanol-Induced Acute Gastric Injury in Rats

The flavonoid myricetin is abundant in vegetables and has various bioactive properties, including anti-inflammatory and antioxidative activities. In the present study, we explored the effects of myricetin on alcohol-induced gastric ulcer in a rat model. To induce gastric ulcer, absolute ethanol (5 mL/kg body weight) was orally administrated to each rat. The positive control and myricetin-treated groups were given oral doses of omeprazole (20 mg/kg) or myricetin (12 mg/kg), respectively, 1 hour prior to the administration of absolute alcohol. We found that pretreatment with myricetin significantly decreased alcohol-induced gastric ulcer, hemorrhage, hyperemia, and epithelial cell loss in the gastric mucosa. Myricetin pretreatment reduced the level of malondialdehyde (MDA) and increased that of total glutathione (GSSG/GSH) and superoxide dismutase (SOD) in gastric tissues. In addition, it elevated the expression levels of cyclooxygenase-1 (COX-1) and prostaglandin E2 (PGE2) and decreased the phosphorylation of nuclear factor kappa B (NF-κB). Together, these results indicate that myricetin effectively inhibits ethanol-induced acute gastric injury by preventing oxidative damage, stimulating PGE2 production, and inhibiting NF-κB activation. We suggest that myricetin may be an alternative treatment for gastric injury caused by alcohol intake.

Biochemical and molecular mechanisms associated with the effect of Phoenix dactylifera seeds on cyclophosphamide-induced hepato-renal toxicities in mice

Cyclophosphamide (CTX) causes severe side effects. Phoenix dactylifera L. showed biomedical values. This study aims to address the biochemical and molecular mechanisms of Phoenix dactylifera seeds extract (PDSE) effects on CTX-induced hepato-renal toxicities in mice. Forty male albino mice were divided into four groups: Gp 1 was served as a negative control, Gp2 was injected intraperitoneally (i.p) with PDSE (200 mg/kg) for 30 consecutive days. Gp3 was injected with CTX single dose (200 mg/kg) and Gp4 was injected with CTX then injected with PDSE. Hematological, biochemical, histopathological alterations, and gene expression for pro-inflammatory cytokine were assessed. GC-MS analysis showed the highest percentages of the peak areas were by Ethyl iso-allocholate, 1-Heptatriacotanol, and 9-12-15-Octadecatrienoic acid 2-3-dihydroxypropyl ester. Treatment with PDSE post-CTX-injection ameliorated the hematological, biochemical, and histological alterations by up-regulating the antioxidant biomarkers and downregulating tumor growth factor beta-1 (TGFβ-1), nuclear factor Kappa-beta (NFκ-β), cyclooxygenase-1 (COX-1) genes.

The role of celecoxib as a potential inhibitor in the treatment of inflammatory diseases - a review

: This article presents a simplified view of celecoxib as a potential inhibitor in the treatment of inflammatory diseases. The enzyme cyclooxygenase (COX) has, predominantly, two isoforms called cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). The former plays a constitutive role that is related to homeostatic effects in renal and platelets, while the latter is mainly responsible for induction of inflammatory effects. Since COX-2 plays an important role in the pathogenesis of inflammatory diseases, it has been signaled as a target for the planning of anti-inflammatory intermediates. Many inhibitors developed and planned for COX-2 inhibition have presented side effects to humans, mainly in the gastrointestinal and/or cardiovascular tract. Therefore, it is necessary to design new potential COX-2 inhibitors, which are relatively safe and without side effects. To this end, of the generation of non-steroidal anti-inflammatory drugs from “coxibs”, celecoxib is the only potent selective COX-2 inhibitor that is still commercially available. Thus, the compound celecoxib became a commercial prototype inhibitor for the development of anti-inflammatory agents for COX-2 enzyme. In this review, we provide highlights where such inhibition should provide a structural basis for the design of promising new non-steroidal anti-inflammatory drugs (NSAIDs) which act as COX-2 inhibitors with lesser side effects on the human body.