Bogusław Okopień

Quantification of metformin by the HPLC method in brain regions, cerebrospinal fluid and plasma of rats treated with lipopolysaccharide

Recently, it has been reported that metformin may attenuate inflammation and directly act on the central nervous system. Using the HPLC method, in Wistar rats, we assessed the changes in metformin concentrations in various brain regions (pituitary gland, olfactory bulb, hypothalamus, cerebellum, hippocampus, striatum, frontal cortex), cerebrospinal fluid and plasma after single and chronic oral administration, in the model of systemic inflammation induced by lipopolysaccharide (ip). Regarding the influence of systemic inflammation on metformin distribution, the pituitary gland demonstrated the highest its level after single and chronic administration (28.8 ± 3.5 nmol/g and 24.9 ± 3.2 nmol/g, respectively). We concluded that orally-dosed metformin rapidly crosses the blood-brain barrier and differently accumulates in structures of the central nervous system.

Effects of HMG-CoA Reductase Inhibitors on Coagulation and Fibrinolysis Processes

Recent large clinical trials have demonstrated that HMG-CoA reductase inhibitors, or statins, markedly reduce morbidity and mortality when used in the primary and secondary prevention of cardiovascular disease. It has been established that the benefits of statin therapy in cardiovascular disease can be explained not only by the lipid-lowering potential of statins but also by nonlipid-related mechanisms (so-called ‘pleiotropic effects’) that contribute to the positive effect of statins on the incidence of cardiovascular events.The coagulation and fibrinolytic systems are two separate but reciprocally linked enzyme cascades that regulate the formation and breakdown of fibrin. Numerous studies have demonstrated that disturbances of coagulation and fibrinolysis contribute to the development and progression of atherosclerosis, and that they affect the incidence of atherosclerosis-related clinical events. High plasma levels or activities of fibrinogen, factor VII, factor VIII, von Willebrand factor (vWF), soluble thrombomodulin, tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) are thought to be associated with increased morbidity and mortality related to cardiovascular disease.Experimental studies and many clinical studies have recently shown that statins produce favourable effects on haemostatic parameters, including those that are risk factors for cardiovascular disease. Statins diminish procoagulant activity, which is observed at different stages of the coagulation cascade, including tissue factor (TF) activity, conversion of prothrombin to thrombin and thrombin activity. In some studies, statins also reduced fibrinogen levels. By altering the levels and activities of tPA and PAI-1, statins seem to stimulate fibrinolysis. The data on the effects of combined treatment with statins and other drugs on haemostasis are rather limited. They suggest that statins combined with fibric acid derivatives, omega-3 fatty acids and 17β-estradiol are superior to statins alone. The only two clinical studies performed in patients with acute coronary syndromes showed a relatively weak effect of statins on haemostasis in those patients. Although various statins may produce different effects on individual variables, there are no convincing data showing that differences in their physicochemical and pharmacokinetic properties significantly alter their net effect on excessive procoagulant activity. Apart from the lipid-lowering effect, statins suppress the synthesis of several important nonsterol isoprenoids derived from the mevalonate pathway, especially farnesyl and geranylgeranyl pyrophosphates, which via enhanced protein prenylation, are involved in the regulation of many cellular processes. It is presumed that the inhibitory effect of statins on the mevalonate pathway is involved in the regulation of some key steps of coagulation and fibrinolysis processes. In this way they probably regulate the synthesis of TF, tPA and PAI-1, and perhaps they also control the generation and activity of thrombin.The beneficial effects of statins on coagulation and fibrinolysis may be responsible for their ability to decrease the number of cardiovascular events. The lipid-independent effects of statins on haemostasis may contribute to the marked decrease in the incidence rates of mortality, hospitalisation and revascularisation in patients treated with these drugs.

Monocyte release of tumor necrosis factor-alpha and interleukin-1beta in primary type IIa and IIb dyslipidemic patients treated with statins or fibrates.

Both 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) as well as peroxisome proliferator-activated receptor (PPAR)α activators (fibrates) proved to be effective in the primary and secondary prevention of cardiovascular diseases. The benefits of hypolipemic therapy in cardiovascular diseases cannot be explained only by the lipid-lowering potential of these agents. The aim of this study was to clarify the effect of hypolipemic agents on proinflammatory cytokine release from human monocytes in relationship with their action on plasma levels of sensitive systemic marker of low-grade vascular inflammation. Plasma lipid and high-sensitivity C-reactive protein (hsCRP) levels, and the release of tumor necrosis factor-α (TNFα) and interleukin-1β from monocytes were assessed at baseline and 30 and 90 days following randomization of IIa dyslipidemic patients into fluvastatin or simvastatin groups and randomization of type IIb dyslipidemic patients to the micronized form of either ciprofibrate or fenofibrate. Lipopolysaccharide-stimulated monocytes from dyslipidemic patients released significantly more TNFα (types IIa and IIb dyslipidemias) and interleukin-1β (type IIa dyslipidemia) in comparison with monocytes in 59 age-, sex-, and weight-matched control subjects. Their baseline hsCRP levels were also higher. Both statins and fibrates reduced the release of TNFα and interleukin-1β, and lowered plasma hsCRP levels. The effects of hypolipemic agents on cytokine release and plasma hsCRP were unrelated to their lipid-lowering action. Our results have demonstrated that type IIa and IIb dyslipidemic patients exhibit the abnormal pattern of TNFα and interleukin-1β production by activated monocytes. Both HMG-CoA reductase inhibitors and PPARα activators normalize monocytic secretion of these cytokines, and this action may partially contribute to the systemic antiinflammatory effect of hypolipemic agents. The statin- and fibrate-induced suppression of proinflammatory cytokine release from monocytes seems to play a role in their beneficial effect on the incidence of cardiovascular events.

The role of adipokines in connective tissue diseases

ObjectiveTo discuss the relationship between adipokines and connective tissue diseases, by putting special emphasis on the potential role of leptin, adiponectin, resistin, and other adipose tissue products in the pathogenesis of rheumatoid arthritis and systemic lupus erythematosus and on possible application of adipokine-targeted therapy in the treatment of these disorders with emphasis on the recent findings.MethodsPubMed literature search complemented by review of bibliographies listed in identified articles.ResultsMost of the data presented by different research groups showed changed levels of leptin, adiponectin, and resistin and occasionally also other adpokines in rheumatoid arthritis and systemic lupus erythematosus. The relationship between the remaining connective tissue diseases and adipokines is less documented.ConclusionsPlasma levels of adipokines might tell us too little about their role in connective tissue disorders, whereas adipokine effects on synovial tissues might differ from their known metabolic or cardiovascular effects, which implies that some re-appraisal of adipokines role may need to take place. It still remains obscure whether the observed disturbances in various adipokine systems in subjects with connective tissue diseases contribute to their development or only reflect the presence or activity of inflammatory process, which itself is induced by other pro-inflammatory factors.

Pleiotropic Effects of Atorvastatin and Fenofibrate in Metabolic Syndrome and Different Types of Pre-Diabetes

OBJECTIVE To compare extra-lipid effects of statins and fibrates in relation to the baseline metabolic status of patients. RESEARCH DESIGN AND METHODS The study involved a group of 242 metabolic syndrome patients with or without pre-diabetes and randomized to atorvastatin, fenofibrate, or placebo. RESULTS Compared with matched healthy subjects, metabolic syndrome patients exhibited higher plasma levels/activities of high-sensitivity C-reactive protein (hs-CRP), fibrinogen, factor VII, plasminogen activator inhibitor 1, and enhanced monocyte cytokine release. These abnormalities were alleviated by both atorvastatin and fenofibrate treatment. CRP-lowering and monocyte-suppressing actions were more pronounced for atorvastatin in subjects with impaired fasting glucose and for fenofibrate in patients with impaired glucose tolerance. CONCLUSIONS The presence of pre-diabetes potentiates metabolic syndrome–induced abnormalities in plasma markers of inflammation and hemostasis and in monocyte secretory function. Both atorvastatin and fenofibrate exhibit multidirectional pleiotropic effects in subjects with metabolic syndrome, the strength of which seem to be partially determined by the type of pre-diabetes.

Effect of Simvastatin and Fenofibrate on Cytokine Release and Systemic Inflammation in Type 2 Diabetes Mellitus With Mixed Dyslipidemia

The aim of our study was to compare the effect of simvastatin and fenofibrate treatment on the secretory function of human monocytes and lymphocytes and on systemic inflammation in type 2 diabetes and to assess whether their coadministration is superior to treatment with only 1 of these drugs. One hundred ninety-six adult patients with recently diagnosed and previously untreated type 2 diabetes and mixed dyslipidemia, complying throughout the study with lifestyle intervention and treated with metformin, were randomized in a double-blind fashion to receive simvastatin (40 mg), fenofibrate (200 mg), simvastatin plus fenofibrate, or placebo for 90 days. Main outcome measurements were monocyte and lymphocyte release of proinflammatory cytokines and plasma levels of C-reactive protein. One hundred ninety patients completed the study. Simvastatin and fenofibrate decreased monocyte release of tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1 and lymphocyte release of interleukin-2, interferon-γ, and tumor necrosis factor-α, which was accompanied by a decrease in plasma C-reactive protein levels. Anti-inflammatory effects of fenofibrate partly correlated with the improvement in insulin sensitivity. Lymphocyte-suppressing, but not monocyte-suppressing, effect was stronger if these 2 agents were administered together. In conclusion, simvastatin and fenofibrate exhibit a similar effect on the secretory function of human monocytes and lymphocytes and on systemic inflammation in type 2 diabetic subjects with mixed dyslipidemia. This effect may be clinically relevant in the prevention of vascular complications in metformin- and diet-treated subjects with newly diagnosed diabetic dyslipidemia.

The effect of levothyroxine and selenomethionine on lymphocyte and monocyte cytokine release in women with Hashimoto's thyroiditis.

CONTEXT No previous study determined monocyte- and lymphocyte-suppressing effects of levothyroxine and selenomethionine and assessed whether their coadministration is superior to treatment with only one of these drugs. OBJECTIVE Our objective was to compare the effect of levothyroxine and selenomethionine on monocyte and lymphocyte cytokine release and systemic inflammation in patients with Hashimotos thyroiditis. DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION We conducted a randomized clinical trial involving a group of 170 ambulatory euthyroid women with recently diagnosed and previously untreated Hashimotos thyroiditis and 41 matched healthy subjects. Participants were randomized in a double-blind fashion to receive a 6-month treatment with levothyroxine, selenomethionine, levothyroxine plus selenomethionine, or placebo. One hundred sixty-five patients completed the study. MAIN OUTCOME MEASURES Monocyte and lymphocyte release of proinflammatory cytokines and plasma levels of C-reactive protein (CRP) were assessed. RESULTS Compared with the control subjects, monocytes and lymphocytes of Hashimotos thyroiditis patients released greater amounts of all cytokines studied. Levothyroxine reduced monocyte release of TNF-α, IL-1β, IL-6, and monocyte chemoattractant protein-1, whereas selenomethionine inhibited lymphocyte release of IL-2, interferon-γ, and TNF-α, which was accompanied by a reduction in plasma CRP levels. The decrease in cytokine release and in plasma CRP levels was strongest when both drugs were given together. CONCLUSIONS Despite affecting different types of inflammatory cells, levothyroxine and selenomethionine exhibit a similar systemic antiinflammatory effect in euthyroid females with Hashimotos thyroiditis. This action, which correlates with a reduction in thyroid peroxidase antibody titers, may be associated with clinical benefits in the prevention and management of Hashimotos thyroiditis, particularly in subjects receiving both agents.

Effect of atorvastatin and fenofibric acid on adipokine release from visceral and subcutaneous adipose tissue of patients with mixed dyslipidemia and normolipidemic subjects

Because of methodological limitations and conflicting results of studies conducted thus far, the possible involvement of human adipose tissue in pleiotropic effects of statins and fibrates requires better understanding. Samples of visceral and subcutaneous adipose tissue obtained from 23 mixed dyslipidemic patients and 23 normolipidemic subjects were treated in vitro for 48 h with atorvastatin, fenofibric acid or both these agents. Visceral and subcutaneous fat of mixed dyslipidemic patients released more leptin, resistin, interleukin-6, tumor necrosis factor alpha (TNFalpha and plasminogen activator inhibitor-1 (PAI-1), and less adiponectin than respective adipose tissue of patients without lipid abnormalities. In both groups of patients, visceral and subcutaneous tissue varied in the amount of secreted adipokines. In dyslipidemic patients both drugs administered alone affected adipose tissue adiponectin and resistin secretion. Additionally, atorvastatin decreased PAI-1 while fenofibric acid reduced leptin release. A combined administration of atorvastatin and fenofibric acid changed the release of all studied markers by visceral fat but did not affect interleukin-6 and TNFalpha release by subcutaneous tissue. In normolipidemic subjects the effect on adipokine release was more pronounced in visceral fat, in which it was strongest if the drugs were given together. Adipose tissue hormonal activity differs between mixed dyslipidemic and normolipidemic patients and between visceral and subcutaneous adipose tissue. Atorvastatin and fenofibrate exhibit their pleiotropic effects in part by changing the adipokine release by human adipose tissue, regardless of its origin. These effects are stronger in patients with mixed dyslipidemia and are particularly pronounced if atorvastatin and fenofibric acid are given together.

Pleiotropic action of short-term metformin and fenofibrate treatment, combined with lifestyle intervention, in type 2 diabetic patients with mixed dyslipidemia.

OBJECTIVE To compare the effect of short-term metformin and fenofibrate treatment, administered alone or in sequence, on glucose and lipid metabolism, cardiovascular risk factors, and monocyte cytokine release in type 2 diabetic patients with mixed dyslipidemia. RESEARCH DESIGN AND METHODS We studied 128 type 2 diabetic patients with mixed dyslipidemia complying throughout the study with lifestyle intervention who were randomized twice, initially to either metformin or placebo, and then to micronized fenofibrate or placebo. RESULTS Fenofibrate alleviated diabetic dyslipidemia–induced changes in plasma high-sensitivity C-reactive protein, fibrinogen, and plasminogen activator inhibitor (PAI)-1 and in monocyte cytokine release, whereas metformin or lifestyle intervention improved mainly glucose and lipid metabolism. The strongest pleiotropic effect was observed when fenofibrate was added to metformin. CONCLUSIONS Fenofibrate, particularly administered together with metformin, is superior to metformin and lifestyle intervention in exhibiting beneficial effects on systemic inflammation, hemostasis, and monocyte secretory function in type 2 diabetic patients with mixed dyslipidemia.

Metformin has adenosine-monophosphate activated protein kinase (AMPK)-independent effects on LPS-stimulated rat primary microglial cultures

The results of recent studies suggest that metformin, in addition to its efficacy in treating type 2 diabetes, may also have therapeutic potential for the treatment of neuroinflammatory diseases in which reactive microglia play an essential role. However, the molecular mechanisms by which metformin exerts its anti-inflammatory effects remain largely unknown. Adenosine-monophosphate-activated protein kinase (AMPK) activation is the most well-known mechanism of metformin action; however, some of the biological responses to metformin are not limited to AMPK activation but are mediated by AMPK-independent mechanisms. In this paper, we attempted to evaluate the effects of metformin on unstimulated and LPS-activated rat primary microglial cell cultures. The presented evidence supports the conclusion that metformin-activated AMPK participates in regulating the release of TNF-α. Furthermore, the effects of metformin on the release of IL-1β, IL-6, IL-10, TGF-β, NO, and ROS as well as on the expression of arginase I, iNOS, NF-κB p65 and PGC-1α were not AMPK-dependent, because pretreatment of LPS-activated microglia with compound C, a pharmacological inhibitor of AMPK, did not reverse the effect of metformin. Based on the present findings, we propose that the shift of microglia toward alternative activation may underlie the beneficial effects of metformin observed in animal models of neurological disorders.