Niacin in the Treatment of Hyperlipidemias in Light of New Clinical Trials: Has Niacin Lost its Place?

The two coin sides of bacterial extracellular membrane nanovesicles: atherosclerosis trigger or remedy

Among the numerous driving forces that cause the atherosclerotic cardiovascular disease (ASCVD), pathogenic bacterial extracellular membrane nanovesicles (BEMNs) containing toxins and virulence factors appear to be the key trigger of inflammation and atherogenesis, the major processes involved in the pathogenesis of ASCVD. Since BEMNs are the carriers of nanosized biomolecules to distant sites, they are now being considered as a novel drug delivery system. Nowadays, many therapeutic strategies are used to treat ASCVD. However, the conventional anti-atherosclerotic therapies are not effective enough. This primarily due to the inefficiency of non-targeted drug delivery systems to tissue affected areas, which, in turn, leads to numerous side effects, as well as faulty pharmacokinetics. In this regard, nanomedicine methods using nanoparticles (NPs) as targeted drug delivery vehicles proved to be extremely useful. Bioengineered BEMNs equipped with disease-specific ligand moieties and loaded with corresponding drugs represent a promising tool in nanomedicine, which can be used as a novel drug delivery system for a successful therapy of ASCVD. In this review, we outline the involvement of pathogenic BEMNs in the triggering of ASCVD, the conventional therapeutic strategies for the treatment of ASCVD, and the recent trends in nanomedicine using BEMNs and NPs as a vehicle for targeted drug delivery.

Niacin (Vitamin B3)-Induced Acute Fulminant Hepatic Failure in a 24-Year-Old Female

Acute liver failure (ALF) is a rare, life-threatening condition characterized by acute severe liver injury, encephalopathy, and coagulopathy in the absence of prior liver disease. The causes of ALF are broad and varied worldwide, commonly including triggers such as drugs (predominantly paracetamol) in developed countries and viral infections in developing nations. Prompt diagnosis and management are crucial in acute fulminant liver failure as highlighted in this case of a 24-year-old female with ALF secondary to vitamin B3 overdosing. This study further highlights the need for a high degree of clinical suspicion that physicians need to ascertain the cause of acute liver failure, the complexity of its management, and the significant harm unnecessary dietary supplementation can result in. This is a crucial example of why healthcare professionals need to educate their patients about the potential adverse consequences of dietary supplements.

Preventing loss of sirt1 lowers mitochondrial oxidative stress and preserves C2C12 myotube diameter in an in vitro model of cancer cachexia

Cancer cachexia is a multifactorial syndrome associated with advanced cancer that contributes to mortality. Cachexia is characterized by loss of body weight and muscle atrophy. Increased skeletal muscle mitochondrial reactive oxygen species (ROS) is a contributing factor to loss of muscle mass in cachectic patients. Mice inoculated with Lewis lung carcinoma (LLC) cells lose weight, muscle mass, and have lower muscle sirtuin-1 (sirt1) expression. Nicotinic acid (NA) is a precursor to nicotinamide dinucleotide (NAD+) which is exhausted in cachectic muscle and is a direct activator of sirt1. Mice lost body and muscle weight and exhibited reduced skeletal muscle sirt1 expression after inoculation with LLC cells. C2C12 myotubes treated with LLC-conditioned media (LCM) had lower myotube diameter. We treated C2C12 myotubes with LCM for 24 h with or without NA for 24 h. C2C12 myotubes treated with NA maintained myotube diameter, sirt1 expression, and had lower mitochondrial superoxide. We then used a sirt1-specific small molecule activator SRT1720 to increase sirt1 activity. C2C12 myotubes treated with SRT1720 maintained myotube diameter, prevented loss of sirt1 expression, and attenuated mitochondrial superoxide production. Our data provides evidence that NA may be beneficial in combating cancer cachexia by maintaining sirt1 expression and decreasing mitochondrial superoxide production.

Lipid-Derived Biomarkers as Therapeutic Targets for Chronic Coronary Syndrome and Ischemic Stroke: An Updated Narrative Review

The incidence and prevalence of cardiac and cerebrovascular diseases are constantly increasing, with chronic coronary syndrome and ischemic stroke as the leading causes of morbidity and mortality worldwide. According to current knowledge, the heart-brain axis is more than a theoretical concept, with many common pathophysiological mechanisms involved in the onset and evolution of both coronary and cerebral ischemia. Moreover, the focus is on the prevention and early intervention of risk factors in searching for targeted and personalized medical treatment. In this context, this narrative review aims to offer, in a didactic and practice-oriented manner, an up-to-date overview of the role played by lipid-derived biomarkers (from low-density lipoprotein cholesterol to oxylipin and apolipoproteins) in chronic coronary syndrome and ischemic stroke. Firstly, the authors highlight, via relevant epidemiological data, the significant burden of chronic coronary syndrome and ischemic stroke in the general population, thus explaining the need for updated information on this topic. Subsequently, the most important lipid-derived biomarkers and their multiple roles in the pathogenesis of these two disorders are listed. Currently available and experimental targeted therapies based on these lipid-derived biomarkers are presented in the final part of this paper, representing this manuscript's original and novel input.

Curcumin-Based Fixed Dose Combination Products for Cholesterol Management: A Narrative Review

Curcumin, a polyphenol compound that belongs to a class of molecules known as curcuminoids, may interact with various biological macromolecules in the body, including proteins, nucleic acids, and lipids. Curcumin-based fixed-dose combination (FDC) products enhance curcumin stability and bioavailability for better clinical use in cholesterol management. Preclinical studies on curcumin and cholesterol are mostly positive. Obstacles are the variable composition of the many different curcumin-based FDC products, the lack of standards, and the limitation of the randomized controlled trials (RCTs) conducted for specific products. Once these downfalls have been addressed, curcumin-based FDC products have great potential for cholesterol management. They can supplement the uptake of statins, reducing their dosage for the same controlling effects or even replacing them.

Development of New Genome Editing Tools for the Treatment of Hyperlipidemia

Hyperlipidemia is a medical condition characterized by high levels of lipids in the blood. It is often associated with an increased risk of cardiovascular diseases such as heart attacks and strokes. Traditional treatment approaches for hyperlipidemia involve lifestyle modifications, dietary changes, and the use of medications like statins. Recent advancements in genome editing technologies, including CRISPR-Cas9, have opened up new possibilities for the treatment of this condition. This review provides a general overview of the main target genes involved in lipid metabolism and highlights the progress made during recent years towards the development of new treatments for dyslipidemia.

Bile Acid Sequestrants Based on Natural and Synthetic Gels

Bile acid sequestrants (BASs) are non-systemic therapeutic agents used for the management of hypercholesterolemia. They are generally safe and not associated with serious systemic adverse effects. Usually, BASs are cationic polymeric gels that have the ability to bind bile salts in the small intestine and eliminate them by excretion of the non-absorbable polymer-bile salt complex. This review gives a general presentation of bile acids and the characteristics and mechanisms of action of BASs. The chemical structures and methods of synthesis are shown for commercial BASs of first- (cholestyramine, colextran, and colestipol) and second-generation (colesevelam and colestilan) and potential BASs. The latter are based on either synthetic polymers such as poly((meth)acrylates/acrylamides), poly(alkylamines), poly(allylamines) and vinyl benzyl amino polymers or biopolymers, such as cellulose, dextran, pullulan, methylan, and poly(cyclodextrins). A separate section is dedicated to molecular imprinting polymers (MIPs) because of their great selectivity and affinity for the template molecules used in the imprinting technique. Focus is given to the understanding of the relationships between the chemical structure of these cross-linked polymers and their potential to bind bile salts. The synthetic pathways used in obtaining BASs and their in vitro and in vivo hypolipidemic activities are also introduced.

High-Density Lipoprotein in Metabolic Disorders and Beyond: An Exciting New World Full of Challenges and Opportunities

High-density lipoprotein (HDL) is an enigmatic member of the plasma lipid and lipoprotein transport system, best known for its ability to promote the reverse cholesterol efflux and the unloading of excess cholesterol from peripheral tissues. More recently, data in experimental mice and humans suggest that HDL may play important novel roles in other physiological processes associated with various metabolic disorders. Important parameters in the HDL functions are its apolipoprotein and lipid content, further reinforcing the principle that HDL structure defines its functionality. Thus, based on current evidence, low levels of HDL-cholesterol (HDL-C) or dysfunctional HDL particles contribute to the development of metabolic diseases such as morbid obesity, type 2 diabetes mellitus, and nonalcoholic fatty liver disease. Interestingly, low levels of HDL-C and dysfunctional HDL particles are observed in patients with multiple myeloma and other types of cancer. Therefore, adjusting HDL-C levels within the optimal range and improving HDL particle functionality is expected to benefit such pathological conditions. The failure of previous clinical trials testing various HDL-C-raising pharmaceuticals does not preclude a significant role for HDL in the treatment of atherosclerosis and related metabolic disorders. Those trials were designed on the principle of "the more the better", ignoring the U-shape relationship between HDL-C levels and morbidity and mortality. Thus, many of these pharmaceuticals should be retested in appropriately designed clinical trials. Novel gene-editing-based pharmaceuticals aiming at altering the apolipoprotein composition of HDL are expected to revolutionize the treatment strategies, improving the functionality of dysfunctional HDL.

Impact of Berberine or Berberine Combination Products on Lipoprotein, Triglyceride and Biological Safety Marker Concentrations in Patients with Hyperlipidemia: A Systematic Review and Meta-Analysis

Monoclonal antibody Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) inhibitors reduce total cholesterol (TC), low density lipoproteins (LDL), high density lipoproteins (HDL), and triglycerides (TG). We assessed the ability of berberine, a natural PCSK9 inhibitor, to reduce lipid concentrations either alone or combined with other nutraceuticals. We searched PubMed, Scopus and EMBASE from inception to September 30th, 2022 for randomized controlled trials (RCTs) assessing 8-18 wk of berberine therapy on. A total of 41 RCTs with 4,838 patients met our inclusion criteria. Berberine containing products significantly reduced TC (MD -17.42 mg/dL [95%CI: -22.91 to -11.93]), LDL (MD -14.98 mg/dL [95%CI: -20.67 to -9.28]), and TG (MD -18.67 mg/dL [95%CI: -25.82 to -11.51]) while raising HDL (MD 1.97 mg/dL [95%CI: 1.16 to 2.78]) versus control (I2 > 72% for all analyses). Products with berberine alone had less robust effects on TC (MD -12.08 mg/dL [95%CI: -21.79 to -2.37]), LDL (MD -9.26 mg/dL [95%CI: -20.31 to 1.78]), and HDL (MD 1.38 mg/dL [95%CI: -1.27 to 4.03]) but TG effects were similar (MD -17.40 mg/dL [95%CI: -32.57 to -2.23]). Berberine along with red yeast rice reduced TC (MD -19.62 mg/dL [95%CI: -28.56 to -10.68]) and LDL (MD -18.79 mg/dL [95%CI: -28.03 to -9.54]) as did combination therapy with Silybum maranium for TC (MD -31.81 mg/dL [95%CI: -59.88 to -3.73]) and LDL (MD -30.82 mg/dL [95%CI: -56.48 to -5.16]). Berberine, alone or with other nutraceuticals, can provide a modest positive impact on lipid concentrations.

Is Niacine a Potential Agent to Decrease Dyslipidemia Risk?

Cardiovascular diseases are the most common non-communicable diseases with the highest prevalence and mortality rate in the all around the world. There are some risk factors -such as modifiable and non-modifiable- which are effective on the development of these diseases. Modifiable risk factors are closely related to dyslipidemia, which forms the basis of cardiovascular diseases. Dyslipidemia is characterized by high triacylglycerol (TAG) and free fatty acids, decreased high density lipoprotein (HDL) level and function, increased low density lipoprotein (LDL) level and apolipoprotein B (Apo B) production. There is a relation between dyslipidemia with nutritional and physical activity behaviors. In particular, adherence to the Mediterranean diet and lifestyle behaviors instead of the Western diet can potentially decrease dyslipidemia risk. On the other hand, some of micronutrients such as niacin can potentially decrease dyslipidemia risk as a nutritional supplement. Niacin -which is a water-soluble, B group vitamin- can potentially decrease TAG, free fatty acids, Apo B, very low density lipoprotein (VLDL) and LDL levels and increase HDL and apolipoprotein A (Apo A) levels in plasma. Due to these potential beneficial effects, niacin acts a pharmacological agent to decrease both of dyslipidemia risk and symptoms. However, niacin is used more than tolerable upper intake level (35 mg/day) to show these potential effects (1-3 g). This situation may cause to ‘niacin flush’ symptom. In addition, there is a need for the studies which aim to determine the negative effects of high dose niacin intake on human’s health in long-term. In this review article, potential effects of the niacin on dyslipidemia are examined within the current literature.

Computational insights on molecular interactions of acifran with GPR109A and GPR109B

Acifran is a well-known agonist of G-protein-coupled receptor protein, namely GPR109A. Acifran is primarily used in the treatment of dyslipidemia, myocardial infractions, and atherosclerosis in humans due to its lower vascular and metabolic side effects. However, experimental and computational studies on interaction sites of acifran with GPR proteins (GPR109A and GPR109B) are lacking. Our computational studies using docking and molecular dynamics simulation revealed that acifran binds distinctly to both GPR109A and GPR109B, but with lower affinity to the latter. The weak binding of acifran-GPR109B is mainly due to the presence of residues S91 and N94 in ECL1 and I178 amino acid in ECL2 region of GPR109B, whereas R111 and R251 residues in TMH3 and TMH6 are crucial for GPR109A-acifran complex stability. Additionally, molecular mechanics/Poisson-Boltzmann solvent accessible surface area (MM/PBSA) analysis revealed that both GPR109A- and GPR109B-acifran complexes are energetically stable with lower calculated binding free energy values for the latter. Energy-minimized structures of GPR109A-acifran and GPR109B-acifran complex.

NAD+ and Vascular Dysfunction: From Mechanisms to Therapeutic Opportunities

Nicotinamide adenine dinucleotide (NAD+) is an essential and pleiotropic coenzyme involved not only in cellular energy metabolism, but also in cell signaling, epigenetic regulation, and post-translational protein modifications. Vascular disease risk factors are associated with aberrant NAD+ metabolism. Conversely, the therapeutic increase of NAD+ levels through the administration of NAD+ precursors or inhibitors of NAD+-consuming enzymes reduces chronic low-grade inflammation, reactivates autophagy and mitochondrial biogenesis, and enhances oxidative metabolism in vascular cells of humans and rodents with vascular pathologies. As such, NAD+ has emerged as a potential target for combatting age-related cardiovascular and cerebrovascular disorders. This review discusses NAD+-regulated mechanisms critical for vascular health and summarizes new advances in NAD+ research directly related to vascular aging and disease, including hypertension, atherosclerosis, coronary artery disease, and aortic aneurysms. Finally, we enumerate challenges and opportunities for NAD+ repletion therapy while anticipating the future of this exciting research field, which will have a major impact on vascular medicine.

High density lipoprotein in atherosclerosis and coronary heart disease: Where do we stand today?

Epidemiological studies during the last five years suggest that a relation between high density lipoprotein cholesterol (HDL-C) levels and the risk for cardiovascular disease (CVD) does exist but follows rather a "U-shaped" curve with an optimal range of HDL-C concentration between 40 and 70 mg/dl for men and 50-70 mg/dl for women. Moreover, as research in the field of lipoproteins progresses it becomes increasingly apparent that HDL particles possess different attributes and depending on their structural and functional characteristics, they may be "antiatherogenic" or "proatherogenic". In light of this information, it is highly doubtful that the choice of experimental drugs and the design of respective clinical trials that put the HDL-C raising hypothesis at test, were the most suitable. Here, we compile the existing literature on HDL, providing a critical up-to-date view that focuses on key data from the biochemistry, epidemiology and pharmacology of HDL, including data from clinical trials. We also discuss the most up-to-date information on the contribution of HDL structure and function to the prevention of atherosclerosis. We conclude by summarizing important differences between mouse models and humans, that may explain why pharmacological successes in mice turn out to be failures in humans.

HDL and type 2 diabetes: the chicken or the egg?

HDL is a complex macromolecular cluster of various components, such as apolipoproteins, enzymes and lipids. Quality evidence from clinical and epidemiological studies led to the principle that HDL-cholesterol (HDL-C) levels are inversely correlated with the risk of CHD. Nevertheless, the failure of many cholesteryl ester transfer protein inhibitors to protect against CVD casts doubts on this principle and highlights the fact that HDL functionality, as dictated by its proteome and lipidome, also plays an important role in protecting against metabolic disorders. Recent data indicate that HDL-C levels and HDL particle functionality are correlated with the pathogenesis and prognosis of type 2 diabetes mellitus, a major risk factor for CVD. Hyperglycaemia leads to reduced HDL-C levels and deteriorated HDL functionality, via various alterations in HDL particles' proteome and lipidome. In turn, reduced HDL-C levels and impaired HDL functionality impact the performance of key organs related to glucose homeostasis, such as pancreas and skeletal muscles. Interestingly, different structural alterations in HDL correlate with distinct metabolic abnormalities, as indicated by recent data evaluating the role of apolipoprotein A1 and lecithin-cholesterol acyltransferase deficiency in glucose homeostasis. While it is becoming evident that not all HDL disturbances are causatively associated with the development and progression of type 2 diabetes, a bidirectional correlation between these two conditions exists, leading to a perpetual self-feeding cycle.

Interaction between high-density lipoproteins and inflammation: Function matters more than concentration!

High-density lipoprotein (HDL) plays an important role in lipid metabolism and especially contributes to the reverse cholesterol transport pathway. Over recent years it has become clear that the effect of HDL on immune-modulation is not only dependent on HDL concentration but also and perhaps even more so on HDL function. This review will provide a concise general introduction to HDL followed by an overview of post-translational modifications of HDL and a detailed overview of the role of HDL in inflammatory diseases. The clinical potential of HDL and its main apolipoprotein constituent, apoA-I, is also addressed in this context. Finally, some conclusions and remarks that are important for future HDL-based research and further development of HDL-focused therapies are discussed.

Trigonelline induces browning in 3T3-L1 white adipocytes

Trigonelline, a major alkaloid component of fenugreek, has been demonstrated to have several biological activities, including antidiabetic and anticancer effects. This study aimed to examine the possible application of trigonelline as an anti-obesity compound based on an investigation of its enhancement of lipid catabolism and induction of browning in white adipocytes. Trigonelline induces browning of 3T3-L1 white adipocytes by enhancing the expressions of brown-fat signature proteins and genes as well as beige-specific genes, including Cd137, Cited1, Tbx1, and Tmem26. Trigonelline also improves lipid metabolism in white adipocytes by decreasing adipogenesis and lipogenesis as well as promotes lipolysis and fatty acid oxidation. Moreover, trigonelline increases the expression of Cox4, Nrf1, and Tfam genes that are responsible for mitochondrial biogenesis. Mechanistic studies revealed that the browning effect of trigonelline in 3T3-L1 white adipocytes is mediated by activating β3-AR and inhibiting PDE4, thereby stimulating the p38 MAPK/ATF-2 signaling pathway. Considering its high bioavailability in humans and the results of this study, trigonelline may have potential as an anti-obesity compound.

Drug Therapy of Dyslipidemia in the Elderly

Abnormal lipoprotein metabolism is an important and modifiable risk factor for atherosclerotic cardiovascular disease (ASCVD), which has been shown in numerous studies to lead to adverse cardiovascular outcomes. As cardiovascular disease (CVD) remains the major cause of morbidity and mortality globally, management of dyslipidemia is a key component of primary and secondary risk-reduction strategies. Because ASCVD risk increases with age, as the population ages, many more people-particularly the elderly-will meet guideline criteria for drug treatment. Statins (HMG-CoA reductase inhibitors) have an unequivocal benefit in reducing ASCVD risk across age groups for secondary prevention. However, the benefit of these drugs for primary prevention in those > 75 years of age remains controversial. We strongly believe that statins should be offered for primary prevention to all older individuals after a shared decision-making process that takes polypharmacy, frailty, and potential adverse effects into consideration. When considering statin therapy in the very old, competing risks of death, and therefore the likelihood that patients will live long enough to benefit from drug therapy, should inform this process. Combination therapies with ezetimibe or proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors should be considered to facilitate the use of tolerable doses of statins. Future investigations of dyslipidemia therapies must appropriately include this at-risk population to identify optimal drugs and drug combinations that have a high benefit:risk ratio for the prevention of ASCVD in the elderly.

Polymeric bile acid sequestrants: Review of design, in vitro binding activities, and hypocholesterolemic effects

Polymeric bile acid sequestrants (BAS) have recently attracted much attention as lipid-lowering agents. These non-absorbable materials specifically bind bile acids (BAs) in the intestine, preventing bile acid (BA) reabsorption into the blood through enterohepatic circulation. Therefore, it is important to understand the structure-property relationships between the polymer sequestrant and its ability to bind specific BAs molecules. In this review, we describe pleiotropic effects of bile acids, and we focus on BAS with various molecular architectures that result in different mechanisms of BA sequestration. Here, we present 1) amphiphilic polymers based on poly(meth)acrylates, poly(meth)acrylamides, polyalkylamines and polyallylamines containing quaternary ammonium groups, 2) cyclodextrins, and 3) BAS prepared via molecular imprinting methods. The synthetic approaches leading to individual BAS preparation, as well as results of their in vitro BA binding activities and in vivo lipid-lowering activities, are discussed.

Effects of an Enriched Extract of Paeoniflorin, a Monoterpene Glycoside used in Chinese Herbal Medicine, on Cholesterol Metabolism in a Hyperlipidemic Rat Model

BACKGROUND Paeoniflorin is a monoterpene glycoside extracted from the roots of Paeonia lactiflora and is used in Chinese herbal medicine to treat hyperlipidemia. The aim of this study was to evaluate the effects of an enriched extract of paeoniflorin on cholesterol levels, hemodynamics, and oxidative stress in a hyperlipidemic rat model. MATERIAL AND METHODS Male Sprague-Dawley rats were fed high-cholesterol diets and treated with three different doses of paeoniflorin for 12 weeks. The effects of paeoniflorin treatment were assessed on cholesterol levels, cholesterol metabolism, red blood cell vascular flow using hemorheology, antioxidant enzymes, and expression of the rate-limiting enzyme in the mevalonate pathway, 3-hydroxy-3-methylglutharyl-coenzyme A reductase (HMG-CoAR). Rat liver histology and immunohistochemical analysis were performed to evaluate the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), cytochrome P450 7A1 (CYP7A1), and peroxisome proliferator-activated receptors (PPAR)-α. Protein expression HMG-CoAR, low-density lipoprotein receptor (LDLR), PPAR-α and CYP7A1 was measured by Western blotting. Antioxidant activity in rat liver was determined by measuring superoxide dismutase (SOD) and malondialdehyde (MDA). RESULTS Serum and hepatic cholesterol, hepatic steatosis and the products of cholesterol metabolism were reduced by paeoniflorin treatment, which also reduced the activity of HMG-CoAR and upregulated the expression of LDLR, PPAR-α, and CYP7A1 expression, increased SOD, decreased MDA, and upregulated Nrf2 expression. CONCLUSIONS The findings of this study in a rat model of hyperlipidemia have shown that paeoniflorin regulates hepatic cholesterol synthesis and metabolism and may also protect the liver from oxidative stress.

Targeting NAD+ in Metabolic Disease: New Insights Into an Old Molecule

Nicotinamide adenine dinucleotide (NAD+) is an established cofactor for enzymes serving cellular metabolic reactions. More recent research identified NAD+ as a signaling molecule and substrate for sirtuins and poly-adenosine 5'-diphosphate polymerases; enzymes that regulate protein deacetylation and DNA repair, and translate changes in energy status into metabolic adaptations. Deranged NAD+ homeostasis and concurrent alterations in mitochondrial function are intrinsic in metabolic disorders, such as type 2 diabetes, nonalcoholic fatty liver, and age-related diseases. Contemporary NAD+ precursors show promise as nutraceuticals to restore target tissue NAD+ and have demonstrated the ability to improve mitochondrial function and sirtuin-dependent signaling. This review discusses the accumulating evidence for targeting NAD+ metabolism in metabolic disease, maps the different strategies for NAD+ boosting, and addresses the challenges and open questions in the field. The health potential of targeting NAD+ homeostasis will inform clinical study design to identify nutraceutical approaches for combating metabolic disease and the unwanted effects of aging.

Pleiotropic effects of niacin: Current possibilities for its clinical use

Niacin was the first hypolipidemic drug to significantly reduce both major cardiovascular events and mortality in patients with cardiovascular disease. Niacin favorably influences all lipoprotein classes, including lipoprotein[a],and belongs to the most potent hypolipidemic drugs for increasing HDL-C. Moreover, niacin causes favorable changes to the qualitative composition of lipoprotein HDL. In addition to its pronounced hypolipidemic action, niacin exerts many other, non-hypolipidemic effects (e.g., antioxidative, anti-inflammatory, antithrombotic), which favorably influence the development and progression of atherosclerosis. These effects are dependent on activation of the specific receptor HCA2. Recent results published by the two large clinical studies, AIM-HIGH and HPS2-THRIVE, have led to the impugnation of niacin's role in future clinical practice. However, due to several methodological flaws in the AIM-HIGH and HPS2-THRIVE studies, the pleiotropic effects of niacin now deserve thorough evaluation. This review summarizes the present and possible future use of niacin in clinical practice in light of its newly recognized pleiotropic effects.

The use of a hydrogel matrix for controlled delivery of niacin to the gastrointestinal tract for treatment of hyperlipidemia

Hyperlipidemia treatment based on niacin requires gastrointestinal administration of relatively high doses. The recommended dietary allowance of niacin as vitamin B3 is 14 to 16 mg daily in adults, while the doses of niacin used in the treatment of hyperlipidemia are generally in the range of 1 to 3 g. Administration of such large doses requires a high concentration of the active compound in the tablet and proper control of the drug release. In this study, a hydrogel matrix based on poly(2-hydroxyethyl methacrylate) and polyvinylpyrrolidone was investigated as delivery vehicle for controlled NA release into the gastrointestinal environment. The prepared hydrogel matrices varied in used monomer and crosslinker types and concentrations. The content of NA in tablets was between 65-80 %. The release profiles of NA from tablets were examined under three different pH values (1, 4.5 and 6.8) over the time period of 30 h. The effects of the monomer ratio, the crosslinking of the polymer network, and the solubility of niacin during drug release under various pH are discussed. The results showed that the release time period can be achieved in a relatively wide range of time and can be adjusted according to the medical requirements.

Treatment of Hypertriglyceridemia: a Review of Current Options

Hypertriglyceridemia is an important marker of increased levels of highly atherogenic remnant-like particles. The importance of lowering plasma levels of triglycerides (TG) has been called into question many times, but currently it is considered an integral part of residual cardiovascular risk reduction strategies. Lifestyle changes (improved diet and increased physical activity) are effective TG lowering measures. Pharmacological treatment usually starts with statins, although associated TG reductions are typically modest. Fibrates are currently the drugs of choice for hyperTG, frequently in combination with statins. Niacin and omega-3 fatty acids improve control of triglyceride levels when the above measures are inadequately effective. Some novel therapies including anti-sense oligonucleotides and inhibitors of microsomal triglyceride transfer protein have shown significant TG lowering efficacy. The current approach to the management of hypertriglyceridemia is based on lifestyle changes and, usually, drug combinations (statin and fibrate and/or omega-3 fatty acids or niacin).