[Antiinflammatory therapy in ostheoarthritis including omega 3 and omega 6 fatty acids]

Osteoarthritis (ostheoarthrosis, OA) is characterized by progressive destruction of articular cartilage, remodeling of the periarticular bone and inflammation of the synovial membrane. In patients occur joints pain, impaired joints motion and disability. The results of many studies indicate an inflammation as foundation of this disease. The management of OA include a combination of pharmacological treatments and nonpharmacological interventions. Pharmacological treatments include used paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs) and chondroprotectives (glucosamine, chondroitin sulfate and so on). NSAIDs long-term use associated with serious adverse effects. OA symptoms are effectively reduced by nutrients such omega 3 and omega 6 fatty acids (PUFAs as EPA, DHA), which decrease the need for non-steroidal drugs and may less adverse events. They exerts, particularly EPA, anti-inflammatory effect, inhibit catabolic processes, stimulate the anabolic process in the cartilage in the joint. Many different evidence validate that omega 3 alleviate the progression of osteoarthritis and have exciting therapeutic potential for preventing cartilage degradation associated with chronic inflammatory in joints.

[Cyclooxygenases inhibitors and other compounds with antiinflammatory potential in osteoarthrosis--part II]

NO-NSAIDs (or CINODs that is COX-inhibiting nitric oxide donors) are new class of antiinflammatory drugs and have a multi-pathway mechanism of action that involves cyclooxygenases (COXs) inhibition and nitric oxide (NO) donation. The first drug of this group is naproxcinod, which exerts rarely adverse effects of stomach, gut and less cardiovascular toxicity with naproxen. NO is an important mediator of endothelial function acting as a vasodilator and plays role in inflammation and pain perception that may be of relevance in osteoarthritis and in healing injures in stomach and gut. Lipoxins (LX, LXs): LXA4, LXB4 are group of lipid mediators leading to resolution of inflammation and protective influence on gastrointestinal mucosa. ATL (AT mean aspirin triggered therefore "depend on aspirin") synthesis, via COX-2, reduces the severity of damage gastrointestinal tract induced by NSAIDs. ATL also plays role in gastric adaptation during chronic aspirin administration. Antiinflammatory drugs hydrogen sulfide-releasing (H2S) (ATB-337 that consist of diclofenac linked to a hydrogen sulfide-releasing moiety) may show better efficacy and less toxicity. COX/5-LOX inhibitors and NO-NSAIDs heals symptoms of osteoarthrosis.

[Cyclooxygenases inhibitors and other compounds with antiinflammatory potential in osteoarthrosis--part I]

Nonsteroidal antiinflammatory drugs (NSAIDs) contain conventional nonselective drugs and selective inhibitors cyclooxygenase-2 (ICOX-2). NSAIDs frequently cause adverse effects tied with cyclooxygenases (COX, COXs) inhibition and prostaglandins (PG, PGs) synthesis, which exerts different physiological effects and are involved in the patophysiology of osteoarthritis. NSAIDs don't inhibit leucotriens (LT LTs) generation. Nonselective drugs cause detrimental results in the gastrointestinal tract. Selective COX-2 inhibitors exert thrombotic cardiovascular events and other negative effects in cardiovascular system. NSAIDs can intensify symptoms of OA and accelerate its progress. Analgetic and antiinflammatory properties possess also licofelone, a competitive inhibitor of cyclooxygenases and 5-lipooxygenase (5-LOX), which presents well gastrointestinal tract tolerability in contrast to NSAIDs. Licofelone decreases the production of proinflammatory leucotrienes and prostaglandins. Moreover inhibition of 5-lipooxygenase activity can delay of cartilago degradation.

[What is new about nonsteroidal antiinflamatory drugs?]

NSAIDs contain nonselective cyclooksygenase inhibitors (for COX-1 and COX-2), inhibitors to the preferential COX-2, the coxibs (sulphonamides, methylsulphones, phenylacethic acid derivatives) with 1000 fold selectivities for COX-2. COX-2 enzyme isoform are constitutively expressed in normal gastric tissue in animals and humans, in the cardiovascular system, renal, central nervous system and other. COX-2 is involved in the ischemic preconditioning mechanism and sulphones have a prooxidant activity. COX-2 inhibitors increased risk for thrombotic cardiovascular events. Long-term study VIGOR, CLASS, TARGET MEDAL revealed that celecoxib, rofecoxib, lumiracoxib, etoricoxib significantly reduced the risk of major gastrointestinal effects (ulcers, perforations, bleeding) than nonselective NSAIDs, but the rates of complicated upper gastrointestinal events were similar for etoricoxib and diclofenac. Only in VIGOR trial incidence of cardiovascular events was greater. No evidence that concomitant ASA reduced risk for cardivascular events. Potential differences in cardiovascular outcomes with the selective COX-2 inhibitors may be due to differences in the drugs molecular structures, pharmacokinetics and pharmacodynamics. In the "prothrombotic environment" contribution disorders in the balance between thromboxan A2 and prostacyclin, increased aggregation plaque, hypertension, endothelial cell dysfunction, impaired angiogenesis. Moreover COX-2 may plays a crucial role in atherosclerotic plaque stability or instability. The cardiovascular risk may be dose related and depends on duration therapy, variable selectivity for COX-2.

[Omapatrilat--new drug for patients with hypertension and heart failure]

Omapatrilat is a dual angiotensin converting enzyme and neutral endopeptidase inhibitor. It is another a new class of drugs, which are effective in the treatment of patients with hypertension and heart failure also accompanying diabetes. They are producing difference endocrine changes, vasodilatation, diuresis, natriuresis and they have anti hypertrophic activity on tissues, reduce sympathetic tone. Omapatrilat produces beneficial effects in experimental animals and in clinical studies. The overall safety with omapatrilat appears to be good. Angioedema is a rare but potentially life threatening side-effects of endopeptidase inhibitors. Treatment with omapatrilat has a higher tendency towards preventing death and worsening heart failure.

Influence of doxorubicin and carnosine on the standard 12-lead electrocardiogram in rabbits

Doxorubicin (DOX) is an anthracycline antibiotic with a potent anticancer activity used against human neoplasms. Doxorubicin causes numerous adverse effects i.e., toxic effect on the cardiovascular system of experimental animals and humans. DOX may provoke a few types of cardiomyopathies: an acute, subacute, chronic and late-onset one. Changes in ECG can be observed at any stage of cardiovascular abnormalities. Abnormal ECG findings may initially be transient in character, whereas continued use of anthracyclines may lead to their fixation. ECG has been suggested as one of the methods allowing to detect cardiotoxicity of anthracycline antibiotics. The usefulness of ECG in assessment of anthracycline cardiotoxicity in experimental animals has been indicated by various authors. In our experiments, we wanted to find out whether carnosine (CAR)--a naturally occurring antioxidant, a dipeptide commonly occurring in the human organism, can influence the potential changes in standard ECG of DOX-treated rabbits, which could indicate its cardioprotective effect.

[Clinical application of cyclooxygenase-2 inhibitors]

Nonsteroidal antiinflammatory drugs (NSAIDs) are a group of compounds with similar therapeutic and side effects. Their therapeutic effects depend on blockade of prostaglandin synthesis through enzyme cyclooxygenase (COX) inhibition. Two isoforms of the enzyme cyclooxygenase have been identified: COX-1 and COX-2. Selective COX-2 inhibitors i.e. meloxicam, nimesulid, etodolac or highly selective COX-2 inhibitors i.e. celecoxib, rofecoxib have antiinflammatory and analgesic properties with less or no gastrointestinal or other NSAIDs-typical adverse effects. Highly selective COX-2 inhibitors may also be active in colonic polyposis, colorectal cancer and Alzheimer's disease.

[Antiarrhythmic properties of angiotensin converting enzyme inhibitors]

In animal experimental models angiotensin converting enzyme (ACE) inhibitors have been found to reduce arrhythmias. In patients with cardiovascular disorders treated with ACE inhibitors the reduction of incidence and the severity of arrhythmias as well as the decrease mortality have been observed. There is little evidence to prove that ACE inhibitors affect directly the electrophysiological function of a heart. It seems that antiarrhythmic effects of ACE inhibitors are indirect.

Evaluation of antiarrhythmic activity of captopril and enalaprilat in experimental cardiac arrhythmias in rabbits. Part II

The influence of 21-day administration of captopril and enalaprilat on barium chloride and adrenaline-induced experimental arrhythmias was assessed. The experiments were performed on rabbits. Arrhythmias were evoked by two alternative arrhythmogen doses. The patterns of disturbances, their frequency and duration were evaluated on the basis of ECG examination. Antiarrhythmic properties of angiotensin converting enzyme inhibitors administered for 21 days were also compared with their effects after single administration. The results were subjected to statistic analysis. On the basis of the obtained results we were able to establish that repeated administration of enalaprilat decreases the frequency of barium chloride- and adrenaline-induced arrhythmias. Repeated administration of captopril and enalaprilat shortened the duration of adrenaline- and barium chloride-induced arrhythmias. Long-term enalaprilat administration was much more effective in preventing arrhythmias than its single dose, it also proved to be more efficient than either single or repeated administration of captopril.

Evaluation of antiarrhythmic activity of captopril and enalaprilat in experimental cardiac arrhythmias in rabbits. Part I

The present study was undertaken to investigate the influence of captopril and enalaprilat--two different angiotensin converting enzyme (ACE) inhibitors--on experimental cardiac arrhythmias induced by barium chloride, ouabain or adrenaline. The research was carried out on rabbits. Captopril and enalaprilat were administered only once. Arrhythmias were evoked by three different doses of arrhythmogens: ED50 and two higher ones causing rhythm disturbances in 80-100% rabbits. The patterns of arrhythmias as well as their frequency and duration were evaluated on the basis of ECG examination. The results were subjected to statistic analysis. As a result of our research, we were able to establish that ACE inhibitors, when administered at a single dose, did not influence the patterns but changed the frequency and duration of barium chloride-, adrenaline- or ouabain-induced arrhythmias. Captopril and enalaprilat administered at a single dose decreased the frequency of barium chloride- or ouabain- but not adrenaline-induced arrhythmia. A single administration of captopril and enalaprilat limit the duration of arrhythmias caused by barium chloride, ouabain or adrenaline.

The effect of ethanol on arterial blood pressure, central venous pressure and ECG in rabbits treated with the single or multiple dose of amitriptyline or imipramine

Amitriptyline and imipramine given in the single dose insignificantly depressed the arterial blood pressure but significantly elevated the central venous pressure, prolonged the PQ interval and widened the QRS complex. After a prolonged daily treatment, the subsequent 21st dose of either antidepressant significantly depressed the arterial blood pressure; amitriptyline also depressed the central venous pressure. When given chronically, amitriptyline induced rhythm disturbances and the flattening of T-wave, while imipramine caused the widening of the QRS complex, block of the left bundle branch, changes in the T-wave amplitude, elevation in the ST interval. An intravenous infusion of ethanol potentiated those changes. The impairment of atrioventricular conduction occurred more frequently after administration of ethanol jointly with amitriptyline than with imipramine. Physostigmine salicylate elevated the depressed arterial blood pressure, aggravated the impairment of conduction and potentiated rhythm disturbances caused by the interaction of ethanol with antidepressants. In the above interactions with ethanol imipramine was less toxic than amitriptyline.