Mechanism of action of niacin

Therapeutic potential of herbal medicine for the management of hyperlipidemia: latest updates

Hyperlipidemia, the most common form of dyslipidemia, is the main source of cardiovascular disorders, characterized by elevated level of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) with high-density lipoprotein cholesterol (HDL-C) in peripheral blood. It is caused by a defect in lipid metabolism in the surface of Apoprotein C-II or a defect in lipoprotein lipase activity as well as reported in genetic, dietary and environmental factors. Several electronic databases were investigated as information sources, including Google Scholar, PubMed, Web of Science, Scopus, ScienceDirect, SpringerLink, Semantic Scholar, MEDLINE and CNKI Scholar. The current review focused on the risk factors of dyslipidemia, synthetic medication with their side effects and different types of medicinal plants having significant potential for the management of hyperlipidemia. The management of hyperlipidemia mostly involves a constant decrease in lipid level using different remedial drugs like statin, fibrate, bile acid sequestrates and niacin. However, this extensive review suggested that the consequences of these drugs are arguable, due to their numerous adverse effects. The selected parts of herb plants are used intact or their extracts containing active phytoconstituents to regulate the lipids in blood level. It was also noted that the Chinese herbal medicine and combination therapy is promising for the lowering of hyperlipidemia. This review intends to provide a scientific base for future endeavors, such as in-depth biological and chemical investigations into previously researched topics.

Approach to the Patient With Moderate Hypertriglyceridemia

Hypertriglyceridemia is a common lipid disorder encountered in clinical practice. Plasma triglycerides are a marker for the concentration of triglycerides carried in chylomicrons and very low-density lipoprotein particles. A fasting triglyceride level <150 mg/dL is accepted widely as the upper limit of normal range. Guidelines for hypertriglyceridemia are variable without a global consensus on classification and goals for triglyceride levels. A general classification of hypertriglyceridemia is mild < 200 mg/dL, moderate = 200 to 500 mg/dL, moderate to severe = 500 to 1000 mg/dL, and severe > 1000 mg/dL. Because moderate hypertriglyceridemia does increase atherosclerotic cardiovascular disease risk, it is important to determine the underlying etiology to guide appropriate and timely management. This article provides stepwise recommendations on the diagnosis and management of moderate hypertriglyceridemia, based on 3 common scenarios encountered in clinical practice. Initial steps in management include evaluating for secondary contributors, especially diabetes mellitus. Based on patient characteristics, appropriate management decisions include lifestyle adjustments aimed at weight loss and decreasing alcohol consumption and use of statin and nonstatin therapies.

What If Not All Metabolites from the Uremic Toxin Generating Pathways Are Toxic? A Hypothesis

The topic of uremic toxicity has received broad attention from the nephrological community over the past few decades. An aspect that is much less often considered is the possibility that the metabolic pathways that generate uremic toxins also may produce molecules that benefit body functions. Here, we discuss this dualism based on the example of tryptophan-derived metabolites, which comprise elements that are mainly toxic, such as indoxyl sulfate, kynurenine and kynurenic acid, but also beneficial compounds, such as indole, melatonin and indole-3-propionic acid, and ambivalent (beneficial for some aspects and harmful for others) compounds such as serotonin. This dualism can also be perceived at the level of the main receptor of the tryptophan-derived metabolites, the aryl hydrocarbon receptor (AHR), which has also been linked to both harm and benefit. We hypothesize that these beneficial effects are the reason why uremic toxin generation remained preserved throughout evolution. This duality is also not unique for the tryptophan-derived metabolites, and in this broader context we discuss the remote sensing and signaling theory (RSST). The RSST proposes that transporters (e.g., organic anion transporter 1—OAT1; ATP-binding cassette transporter G—ABCG2) and drug metabolizing enzymes form a large network of proteins interacting to promote small molecule remote communication at the inter-organ (e.g., gut–liver–heart–brain–kidney) and inter-organismal (e.g., gut microbe–host) levels. These small molecules include gut microbe-derived uremic toxins as well as beneficial molecules such as those discussed here. We emphasize that this positive side of uremic metabolite production needs more attention, and that this dualism especially needs to be considered when assessing and conceiving of therapeutic interventions. These homeostatic considerations are central to the RSST and suggest that interventions be aimed at preserving or restoring the balance between positive and negative components rather than eliminating them all without distinction.

Causes, clinical findings and therapeutic options in chylomicronemia syndrome, a special form of hypertriglyceridemia

The prevalence of hypertriglyceridemia has been increasing worldwide. Attention is drawn to the fact that the frequency of a special hypertriglyceridemia entity, named chylomicronemia syndrome, is variable among its different forms. The monogenic form, termed familial chylomicronemia syndrome, is rare, occuring in 1 in every 1 million persons. On the other hand, the prevalence of the polygenic form of chylomicronemia syndrome is around 1:600. On the basis of the genetical alterations, other factors, such as obesity, alcohol consumption, uncontrolled diabetes mellitus and certain drugs may significantly contribute to the development of the multifactorial form. In this review, we aimed to highlight the recent findings about the clinical and laboratory features, differential diagnosis, as well as the epidemiology of the monogenic and polygenic forms of chylomicronemias. Regarding the therapy, differentiation between the two types of the chylomicronemia syndrome is essential, as well. Thus, proper treatment options of chylomicronemia and hypertriglyceridemia will be also summarized, emphasizing the newest therapeutic approaches, as novel agents may offer solution for the effective treatment of these conditions.

The impact of lipid-lowering medications on coronary artery plaque characteristics

Atherosclerosis is the predominant cause of coronary artery disease. The last several decades have witnessed significant advances in lipid-lowering therapies, which comprise a central component of atherosclerotic cardiovascular disease prevention. In addition to cardiovascular risk reduction with dyslipidemia management, some lipid-based therapies show promise at the level of the atherosclerotic plaque itself through mechanisms governing lipid accumulation, plaque stability, local inflammation, endothelial dysfunction, and thrombogenicity. The capacity of lipid-lowering therapies to modify atherosclerotic plaque burden, size, composition, and vulnerability should correlate with their ability to reduce disease progression. This review discusses plaque characteristics, diagnostic modalities to evaluate these characteristics, and how they are altered by current and emerging lipid-lowering therapies, all in human coronary artery disease.

PoLA/CFPiP/PCS/PSLD/PSD/PSH guidelines on diagnosis and therapy of lipid disorders in Poland 2021

In Poland there are still nearly 20 million individuals with hypercholesterolaemia, most of them are unaware of their condition; that is also why only ca. 5% of patients with familial hypercholesterolaemia have been diagnosed; that is why other rare cholesterol metabolism disorders are so rarely diagnosed in Poland. Let us hope that these guidelines, being an effect of work of experts representing 6 main scientific societies, as well as the network of PoLA lipid centers being a part of the EAS lipid centers, certification of lipidologists by PoLA, or the growing number of centers for rare diseases, with a network planned by the Ministry of Health, improvements in coordinated care for patients after myocardial infarction (KOS-Zawał), reimbursement of innovative agents, as well as introduction in Poland of an effective primary prevention program, will make improvement in relation to these unmet needs in diagnostics and treatment of lipid disorders possible.

The Expanding Role of Pyridine and Dihydropyridine Scaffolds in Drug Design

Pyridine-based ring systems are one of the most extensively used heterocycles in the field of drug design, primarily due to their profound effect on pharmacological activity, which has led to the discovery of numerous broad-spectrum therapeutic agents. In the US FDA database, there are 95 approved pharmaceuticals that stem from pyridine or dihydropyridine, including isoniazid and ethionamide (tuberculosis), delavirdine (HIV/AIDS), abiraterone acetate (prostate cancer), tacrine (Alzheimer's), ciclopirox (ringworm and athlete's foot), crizotinib (cancer), nifedipine (Raynaud's syndrome and premature birth), piroxicam (NSAID for arthritis), nilvadipine (hypertension), roflumilast (COPD), pyridostigmine (myasthenia gravis), and many more. Their remarkable therapeutic applications have encouraged researchers to prepare a larger number of biologically active compounds decorated with pyridine or dihydropyridine, expandeing the scope of finding a cure for other ailments. It is thus anticipated that myriad new pharmaceuticals containing the two heterocycles will be available in the forthcoming decade. This review examines the prospects of highly potent bioactive molecules to emphasize the advantages of using pyridine and dihydropyridine in drug design. We cover the most recent developments from 2010 to date, highlighting the ever-expanding role of both scaffolds in the field of medicinal chemistry and drug development.

Nutraceutical Combinations in Hypercholesterolemia: Evidence from Randomized, Placebo-Controlled Clinical Trials

There is an increasing number of nutraceutical combinations (NCs) on the market for hypercholesterolemia, although clinical trials to verify their safety and efficacy are scarce. We selected fourteen randomized, placebo-controlled clinical trials (RCTs) on different lipid-lowering NCs in hypercholesterolemic subjects. We described each compound's mechanism of action and efficacy in the mixtures and summarized the clinical trials settings and NCs safety and efficacy results. Almost all NCs resulted efficient against hypercholesterolemia; only one reported no changes. Interestingly, red yeast rice (RYR) was present in eleven mixtures. It is not clear whether the lipid-lowering efficacy of these combinations derives mainly from the RYR component monacolin K "natural statin" single effect. Up to now, few RCTs have verified the efficacy of every single compound vs. NCs to evaluate possible additive or synergistic effects, probably due to the complexity and the high resources request. In conclusion, to manage the arising nutraceutical tide against hypercholesterolemia, it could be helpful to increase the number and robustness of clinical studies to verify the efficacy and safety of the new NCs.

Effects of Dietary Food Components on Cognitive Functions in Older Adults

Population aging has recently been an important issue as the number of elderly people is growing worldwide every year, and the extension of social security costs is financially costly. The increase in the number of elderly people with cognitive decline is a serious problem related to the aging of populations. Therefore, it is necessary to consider not only physical care but also cognitive patterns in the future care of older adults. Since food contains a variety of bioactive substances, dietary patterns may help improve age-related cognitive decline. However, the relationship between cognitive function and individual food components remains ambiguous as no clear efficacy or mechanism has been confirmed. Against this background, this review summarizes previous reports on the biological process of cognitive decline in the elderly and the relationship between individual compounds in foods and cognitive function, as well as the role of individual components of food in cognitive function, in the following order: lipids, carotenoids, vitamins, phenolic compounds, amino acids, peptides, and proteins. Based on the research presented in this review, a proper diet that preserves cognitive function has the potential to improve age-related cognitive decline, Alzheimer's disease, and Parkinson's disease. Hopefully, this review will help to trigger the development of new foods and technologies that improve aging and cognitive functions and extend the healthy life span.

Non-targeted metabonomics to investigate the differences in the properties of ginseng and American ginseng based on rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry

The basic properties of herbal medicines are cold, hot, warm, and cool. The differentiation of these properties is important for the diagnosis and treatment of diseases. Ginseng and American ginseng possess opposite properties of warm and cool, respectively. At present, the mechanisms and the influence of steaming leading to the differences in their properties are not clear and require further investigation. Therefore, nontargeted metabonomics based on liquid chromatography-mass spectrometry was applied to investigate the effects of ginseng, American ginseng, and their variants on the changes in endogenous metabolites in rat urine. A total of 19 potential biomarkers were screened out and identified, of which 17, 7, and 5, were respectively related to warm, cool, and both warm and cool properties with opposite effects. The metabolic pathways corresponded to fatty acids, lipids, glycolysis, and energy metabolisms. The warm and tonic effects of red ginseng are stronger than those of ginseng and consistent with the theory of traditional Chinese medicine. The red American ginseng has cool property; however, the degree of coolness is less than that of American ginseng. This study provides a reference methodology to understand the effects of processing and mechanisms associated with the differences in the properties of herbal medicines.

Triglycerides and cardiovascular disease

PURPOSE OF REVIEW

Triglycerides (TGs) are measured as part of routine lipid profiles but their relationship to cardiovascular disease (CVD) risk has been controversial and overshadowed by high-density lipoprotein cholesterol (HDL-C).

RECENT FINDINGS

Epidemiological studies show a clear relationship of TG-containing lipoproteins including remnant particles with CVD risk with the effect being most clearly demonstrated through the excess risk captured by non-HDL-C compared with low-density lipoprotein-cholesterol (LDL-C). Mendelian randomisation studies show a consistent relationship of gene variants linked to TG metabolism with rates of CVD. Furthermore, meta-analyses of intervention trials with statins and other nonstatin drugs also suggest that reducing TGs is associated with benefits on rates of CVD events. Historical subgroup data from fibrate trials suggest benefits in patients with high TG:HDL ratios but seem to add little to optimized statin therapy. Recent trials with omega-3 fatty acids (specifically eicosapentaenoic acid) have suggested that high-dose formulations in contrast to low dose formulations have benefits on CVD outcomes.

SUMMARY

Further studies with newer agents are required to determine the place of TG-lowering drugs in therapeutic pathways. Trials with agents such as pemafibrate and vupanorsen may finally answer these questions.

Managing dyslipidemia in patients with Type 2 diabetes

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is associated with increased risk for atherosclerotic cardiovascular disease (ASCVD) which is partly related to atherogenic dyslipidemia with raised triglycerides, reduced high-density lipoprotein cholesterol levels, and accompanying lipid changes. Treatment of this dyslipidemia is regarded as a priority to reduce the ASCVD risk in T2DM.

AREAS COVERED

This article reviews the relevant studies and guidelines from the publications related to this area.

EXPERT OPINION

Lifestyle modification should always be encouraged, and statin treatment is indicated in most patients with T2DM based on the outcome of randomized controlled trials. If LDL-C goals are not achieved, first, ezetimibe and subsequently proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors should be added. Patients with T2DM derive greater benefits from ezetimibe and PCSK9 inhibitors due to their higher absolute ASCVD risk compared to patients without T2DM. If triglyceride levels remain elevated, a high dose of eicosapentaenoic acid ethyl ester should be added. Fibrates should be used for severe hypertriglyceridemia to prevent acute pancreatitis. Novel treatments including pemafibrate and inclisiran are undergoing cardiovascular outcome trials, and RNA-based therapies may help to target residual hypertriglyceridemia and high lipoprotein(a) with the long acting treatments offering potential improved adherence to therapy.

Targeting HDL in tumor microenvironment: New hope for cancer therapy

Epidemiological studies have shown that plasma HDL-C levels are closely related to the risk of prostate cancer, breast cancer, and other malignancies. As one of the key carriers of cholesterol regulation, high-density lipoprotein (HDL) plays an important role in tumorigenesis and cancer development through anti-inflammation, antioxidation, immune-modulation, and mediating cholesterol transportation in cancer cells and noncancer cells. In addition, the occurrence and progression of cancer are closely related to the alteration of the tumor microenvironment (TME). Cancer cells synthesize and secrete a variety of cytokines and other factors to promote the reprogramming of surrounding cells and shape the microenvironment suitable for cancer survival. By analyzing the effect of HDL on the infiltrating immune cells in the TME, as well as the relationship between HDL and tumor-associated angiogenesis, it is suggested that a moderate increase in the level of HDL in vivo with consequent improvement of the function of HDL in the TME and induction of intracellular cholesterol efflux may be a promising strategy for cancer therapy.

Dyslipidemia Management in 2020: An Update on Diagnosis and Therapeutic Perspectives

Cardiovascular diseases are the leading cause of death in the modern world and dyslipidemia is one of the major risk factors. The current therapeutic strategies for cardiovascular diseases involve the management of risk factors, especially dyslipidemia and hypertension. Recently, the updated guidelines of dyslipidemia management were presented, and the newest data were included in terms of diagnosis, imaging, and treatment. In this targeted literature review, the researchers presented the most recent evidence on dyslipidemia management by including the current therapeutic goals for it. In addition, the novel diagnostic tools based on theranostics are shown. Finally, the future perspectives on treatment based on novel drug delivery systems and their potential to be used in clinical trials were also analyzed. It should be noted that dyslipidemia management can be achieved by the strict lifestyle change, i.e., by adopting a healthy life, and choosing the most suitable medication. This review can help medical professionals as well as specialists of other sciences to update their knowledge on dyslipidemia management, which can lead to better therapeutic outcomes and newer drug developments.

Emerging Pharmacotherapy to Reduce Elevated Lipoprotein(a) Plasma Levels

Lipoprotein(a) is a unique form of low-density lipoprotein. It is associated with a high incidence of premature atherosclerotic disease such as coronary artery disease, myocardial infarction, and stroke. Plasma levels of this lipoprotein and its activities are highly variable. This is because of a wide variability in the size of the apolipoprotein A moiety, which is determined by the number of repeats of cysteine-rich domains known as "kringles." Although the exact mechanism of lipoprotein(a)-induced atherogenicity is unknown, the lipoprotein has been found in the arterial walls of atherosclerotic plaques. It has been implicated in the formation of foam cells and lipid deposition in these plaques. Pharmacologic management of elevated levels of lipoprotein(a) with statins, fibrates, or bile acid sequestrants is ineffective. The newer and emerging lipid-lowering agents, such as the second-generation antisense oligonucleotides, cholesteryl ester transfer protein inhibitors, and proprotein convertase subtilisin/kexin type 9 inhibitors offer the most effective pharmacologic therapy.

New nicotinic acid-based 3,5-diphenylpyrazoles: design, synthesis and antihyperlipidemic activity with potential NPC1L1 inhibitory activity

Nicotinic acid hydrazide was incorporated into new 4,5-dihydro-5-hydroxy-3,5-diphenylpyrazol-1-yl derivatives. Compounds 6a-h were synthesized, and their antihyperlipidemic activity was evaluated in high cholesterol diet-fed rat model. Compounds 6e, 6f were found to decrease the levels of serum total cholesterol by 14-19% compared to control group. Total triglycerides were also reduced by 24-28% and LDL cholesterol by 16%. As expected from parent niacin, compounds 6e and 6f caused an elevation of HDL cholesterol by 33-41%. Docking study supported the ability of designed compounds to block NPC1L1 active site in a manner similar to that observed with ezetimibe.

Supplementation with Niacin during in vitro maturation improves the quality of porcine embryos

Niacin, also known as vitamin B3, has a pivotal role in energy metabolism, cellular signaling cascades regulating gene expression, and apoptosis. However, the effect of Niacin on porcine early embryo developmental competence remains to be elucidated. The present study aimed to assess the effects of Niacin treatment during in vitro maturation (IVM) on the nuclear maturation of porcine oocytes and subsequent development of in vitro embryos. In addition, the expression profiles of selected genes related to lipid metabolism, oxidative stress, and apoptosis were assessed. The IVM medium was supplemented with different concentrations of Niacin (0, 300, 600, and 900 μM). The results showed that a high concentration of Niacin (900 μM) significantly decreased cumulus expansion compared to the other groups (p < 0.05). No significant difference was observed among the experimental groups for nuclear maturation rate. Niacin treatments (300, 600, and 900 μM) during IVM significantly (p < 0.05) enhanced glutathione levels. Treatment with 300 and 600 μM significantly (p < 0.05) lowered the reactive oxygen species levels compared to treatment with 900 μM and the control group. Niacin supplementation to the IVM media significantly improved the cleavage and blastocyst rates compared to the control group. Supplementation with 300 and 600 μM of Niacin significantly increased the total cell number of blastocysts compared to supplementation with 900 μM or the control groups. Cytoplasmic lipid droplets were significantly reduced after 600 μM treatment. Supplementation of Niacin to IVM media positively affected the relative expression of genes related to energy and oxidative status (SIRT1), pro-apoptosis (BAX), anti-apoptosis (BCL2), and lipid metabolism (ACACA and PNPLA2) in cumulus cells and oocytes. Taken together, Niacin supplementation to porcine IVM media improved the developmental competence of early embryos mainly through protection against oxidative stress and its influence on energy metabolism and apoptosis pathways.

ANGPTL3 and Apolipoprotein C-III as Novel Lipid-Lowering Targets

PURPOSE OF REVIEW

Despite significant progress in plasma lipid lowering strategies, recent clinical trials highlight the existence of residual cardiovascular risk. Angiopoietin-like protein 3 (ANGPTL3) and apolipoprotein C-III (Apo C-III) have been identified as novel lipid-lowering targets.

RECENT FINDINGS

Apo C-III and ANGPTL3 have emerged as novel regulators of triglyceride (TG) and low-density lipoprotein-cholesterol (LDL-C) levels. ANGPTL3 is an inhibitor of lipoprotein lipase (LPL), reducing lipolysis of Apo B-containing lipoproteins. Loss-of-function ANGPLT3 mutations are associated with reduced plasma cholesterol and TG, while novel ANGPLT3 inhibition strategies, including monoclonal antibodies (evinacumab), ANGPLT3 antisense oligonucleotides (IONIS-ANGPTL3-L_Rx), and small interfering RNA (siRNA) silencing techniques (ARO-ANG3), result in increased lipolysis and significant reductions of LDL-C and TG levels in phase I and II clinical trials. Similarly, Apo C-III inhibits LPL while promoting the hepatic secretion of TG-rich lipoproteins and preventing their clearance. Loss-of-function APOC3 mutations have been associated with reduced TG levels. Targeting of Apo C-III with volanesorsen, an APOC3 siRNA, results in significant reduction in plasma TG levels but possibly also increased risk for thrombocytopenia, as recently demonstrated in phase I, II, and III clinical trials. ARO-APOC3 is a novel siRNA-based agent targeting Apo C-III which is currently under investigation with regard to its lipid-lowering efficiency. ANGPTL3 and Apo C-III targeting agents have demonstrated striking lipid-lowering effects in recent clinical trials; however, more thorough safety and efficacy data are required. Here, we evaluate the role of ANGPLT3 and Apo C-III in lipid metabolism, present the latest clinical advances targeting those molecules, and outline the remaining scientific challenges on residual lipid-associated cardiovascular risk.

Lipoprotein(a): a genetic marker for cardiovascular disease and target for emerging therapies

Lipoprotein(a) [Lp(a)] is an established cardiovascular risk factor, and growing evidence indicates its causal association with atherosclerotic disease because of the proatherogenic low-density lipoprotein (LDL)-like properties and the prothrombotic plasminogen-like activity of apolipoprotein(a) [apo(a)]. As genetics significantly influences its plasma concentration, Lp(a) is considered an inherited risk factor of atherosclerotic cardiovascular disease (ASCVD), especially in young individuals. Moreover, it has been suggested that elevated Lp(a) may significantly contribute to residual cardiovascular risk in patients with coronary artery disease and optimal LDL-C levels. Nonetheless, the fascinating hypothesis that lowering Lp(a) could reduce the risk of cardiovascular events - in primary or secondary prevention - still needs to be demonstrated by randomized clinical trials. To date, no specific Lp(a)-lowering agent has been approved for reducing the lipoprotein levels, and current lipid-lowering drugs have limited effects. In the future, emerging therapies targeting Lp(a) may offer the possibility to further investigate the relation between Lp(a) levels and cardiovascular outcomes in randomized controlled trials, ultimately leading to a new era in cardiovascular prevention. In this review, we aim to provide an updated overview of current evidence on Lp(a) as well as currently investigated therapeutic strategies that specifically address the reduction of the lipoprotein.

Recent Updates of Lipoprotein(a) and Cardiovascular Disease

In recent years, epidemiological studies, genome-wide association studies, and Mendelian randomization studies have shown a strong association between increased levels of lipoproteins and increased risks of coronary heart disease and cardiovascular disease (CVD). Although lipoprotein(a) [Lp(a)] was an independent risk factor for ASCVD, the latest international clinical guidelines do not recommend direct reduction of plasma Lp(a) concentrations. The main reason was that there is no effective clinical medicine that directly lowers plasma Lp(a) concentrations. However, recent clinical trials have shown that proprotein convertase subtilisin/kexin-type 9 inhibitors (PCSK9) and second-generation antisense oligonucleotides can effectively reduce plasma Lp(a) levels. This review will present the structure, pathogenicity, prognostic evidences, and recent advances in therapeutic drugs for Lp(a).

Improved effect of a mitochondria-targeted antioxidant on hydrogen peroxide-induced oxidative stress in human retinal pigment epithelium cells

Background

Oxidative damage to retinal pigment epithelial (RPE) cells contributes to the development of age-related macular degeneration, which is among the leading causes of visual loss in elderly people. In the present study, we evaluated the protective role of triphenylphosphonium (TPP)-Niacin against hydrogen peroxide (H₂O₂)-induced oxidative stress in RPE cells.

Methods

The cellular viability, lactate dehydrogenase release, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were determined under treatment with H₂O₂ or pre-treatment with TPP-Niacin. The expression level of mitochondrial related genes and some transcription factors were assessed using real-time polymerase chain reaction (RT-qPCR).

Results

TPP-Niacin significantly improved cell viability, reduced ROS generation, and increased the antioxidant enzymes in H₂O₂-treated ARPE-19 cells. Mitochondrial dysfunction from the H₂O₂-induced oxidative stress was also considerably diminished by TPP-Niacin treatment, along with reduction of the mitochondrial membrane potential (MMP) and upregulation of the mitochondrial-associated gene. In addition, TPP-Niacin markedly enhanced the expression of transcription factors (PGC-1α and NRF2) and antioxidant-associated genes (especially HO-1 and NQO-1).

Conclusion

We verified the protective effect of TPP-Niacin against H₂O₂-induced oxidative stress in RPE cells. TPP-Niacin is believed to protect against mitochondrial dysfunction by upregulating antioxidant-related genes, such as PGC-1α, NRF2, HO-1, and NQO-1, in RPE cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40360-020-00471-w.

Hypertriglyceridemia: new approaches in management and treatment

PURPOSE OF REVIEW

Hypertriglyceridemia (HTG), a form of dyslipidemia characterized by elevated plasma of triglycerides (TG), is associated with an increased risk for acute pancreatitis. Moreover, HTG has recently been shown to be linked to the development of atherosclerotic cardiovascular disease (ASCVD); therefore, there is a great interest in better understanding the pathophysiology of HTG and improving its clinical management. In this review, we briefly describe TG metabolism, recent guidelines for the clinical management of HTG and provide an overview of the current and potential new therapies for HTG.

RECENT FINDINGS

Screening patients for HTG is valuable for not only identifying patients with extreme TG elevations, who are at risk for pancreatitis, but also for managing ASCVD risk in patients with more moderate forms of HTG. Therefore, the most recent USA guidelines for cardiovascular diseases recommend using TG as a risk enhancer test, leading to a more aggressive treatment of patients with intermediate risk. Currently, there are several available approaches for reducing plasma TG, which include lifestyle changes, fibrates and omega-3 fatty acid treatment. The addition of eicosapentaenoic acid (EPA) on top of statins has recently been shown to significantly reduce ASCVD events. Nevertheless, there is an unmet need for more effective treatment options. Several new therapies based on newly identified targets in TG metabolism, such as apolipoprotein C-III and angiopoietin-like 3 protein, are currently under development.

SUMMARY

The clinical management of HTG is important in the prevention and treatment of acute pancreatitis and also impacts on how ASCVD risk is managed. More work needs to be done to establish the mechanism for the ability of how EPA lowers ASCVD and how to best integrate it with other lipid-lowering therapies. The efficacy and safety of the novel therapies for HTG should be established soon in the ongoing late-stage clinical trials.

LDL, HDL and endocrine-related cancer: From pathogenic mechanisms to therapies

Cholesterol is essential for a variety of functions in endocrine-related cells, including hormone and steroid production. We have reviewed the progress to date in research on the role of the main cholesterol-containing lipoproteins; low-density lipoprotein (LDL) and high-density lipoprotein (HDL), and their impact on intracellular cholesterol homeostasis and carcinogenic pathways in endocrine-related cancers. Neither LDL-cholesterol (LDL-C) nor HDL-cholesterol (HDL-C) was consistently associated with endocrine-related cancer risk. However, preclinical studies showed that LDL receptor plays a critical role in endocrine-related tumor cells, mainly by enhancing circulating LDL-C uptake and modulating tumorigenic signaling pathways. Although scavenger receptor type BI-mediated uptake of HDL could enhance cell proliferation in breast, prostate, and ovarian cancer, these effects may be counteracted by the antioxidant and anti-inflammatory properties of HDL. Moreover, 27-hydroxycholesterol a metabolite of cholesterol promotes tumorigenic processes in breast and epithelial thyroid cancer. Furthermore, statins have been reported to reduce the incidence of breast, prostate, pancreatic, and ovarian cancer in large clinical trials, in part because of their ability to lower cholesterol synthesis. Overall, cholesterol homeostasis deregulation in endocrine-related cancers offers new therapeutic opportunities, but more mechanistic studies are needed to translate the preclinical findings into clinical therapies.

Managing hyperlipidaemia in patients with COVID-19 and during its pandemic: An expert panel position statement from HEART UK

The emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes Coronavirus Disease 2019 (COVID-19) has resulted in a pandemic. SARS-CoV-2 is highly contagious and its severity highly variable. The fatality rate is unpredictable but is amplified by several factors including advancing age, atherosclerotic cardiovascular disease, diabetes mellitus, hypertension and obesity. A large proportion of patients with these conditions are treated with lipid lowering medication and questions regarding the safety of continuing lipid-lowering medication in patients infected with COVID-19 have arisen. Some have suggested they may exacerbate their condition. It is important to consider known interactions with lipid-lowering agents and with specific therapies for COVID-19. This statement aims to collate current evidence surrounding the safety of lipid-lowering medications in patients who have COVID-19. We offer a consensus view based on current knowledge and we rated the strength and level of evidence for these recommendations. Pubmed, Google scholar and Web of Science were searched extensively for articles using search terms: SARS-CoV-2, COVID-19, coronavirus, Lipids, Statin, Fibrates, Ezetimibe, PCSK9 monoclonal antibodies, nicotinic acid, bile acid sequestrants, nutraceuticals, red yeast rice, Omega-3-Fatty acids, Lomitapide, hypercholesterolaemia, dyslipidaemia and Volanesorsen. There is no evidence currently that lipid lowering therapy is unsafe in patients with COVID-19 infection. Lipid-lowering therapy should not be interrupted because of the pandemic or in patients at increased risk of COVID-19 infection. In patients with confirmed COVID-19, care should be taken to avoid drug interactions, between lipid-lowering medications and drugs that may be used to treat COVID-19, especially in patients with abnormalities in liver function tests.

Lipid-lowering Therapies in Myositis

PURPOSE OF REVIEW

The use of lipid-lowering therapies in patients with idiopathic inflammatory myopathies (IIM) is complicated and there are no guidelines for diagnosing, monitoring, or treating atherosclerotic cardiovascular disease (ASCVD) in this group of patients.

RECENT FINDINGS

The use of lipid-lowering therapies, especially statins, is recommended in patients with increased risk for ASCVD, which includes patients with inflammatory diseases, based on recent American College of Cardiology/American Heart Association (ACC/AHA) guidelines for ASCVD management. There is accumulating evidence that patients with IIM are at increased risk for ASCVD, similar to other inflammatory diseases. Lipid-lowering therapies have side effects that may be pronounced or confounding in myositis patients, potentially limiting their use. Statins are specifically contraindicated in patients with anti 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) antibodies. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been shown to be safe and potentially beneficial in patients with IIM. Here, we propose a framework for (1) ASCVD risk assessment and treatment based on ACC/AHA ASCVD primary prevention guidelines; (2) myositis disease monitoring while undergoing lipid-lowering therapy; and (3) management of statin intolerance, including, indications for the use of PCSK9 inhibitors.

Efficacy and safety of add on therapies in patients with hypercholesterolemia undergoing statin therapy

INTRODUCTION

Statins are the first-line treatment to reduce cardiovascular (CV) events, mainly by reducing low-density-lipoprotein cholesterol (LDL-C), but many patients need additional treatments to reach the current lipid goals.

AREAS COVERED

Herein, the authors review the published literature on the efficacy and safety of the therapies that are most often added to statins to achieve lipid targets.

EXPERT OPINION

Ezetimibe is usually the first additional treatment to achieve LDL-C targets. It reduces LDL-C by about a further 20% and has an excellent safety and tolerability profile. The monoclonal antibody proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, evolocumab, and alirocumab, can reduce LDL-C by ≥50% when added to statins and they also have a well-established safety and tolerability record. The recently approved bempedoic acid is well tolerated and appears to be free of skeletal muscle-related problems, but the CV outcome study with this drug has not been completed. Inclisiran, a small-interfering RNA targeting PCSK9 is at an advanced stage of development and the available data indicate a satisfactory safety profile and LDL-C lowering efficacy similar to the PCSK9 monoclonal antibodies with the advantage of less frequent administration.

Nicotinic acid transport into human liver involves organic anion transporter 2 (SLC22A7)

Nicotinic acid (NA) and nicotinamide (NAM) are biosynthetic precursors of nicotinamide adenine dinucleotide (NAD⁺) - a physiologically important coenzyme that maintains the redox state of cells. Mechanisms driving their entry into cells are not well understood. Here we evaluated the hepatic uptake mechanism(s) of NA and NAM using transporter-transfected cell systems and primary human hepatocytes. NA showed robust organic anion transporter (OAT)2-mediated transport with an uptake ratio (i.e., ratio of accumulation in transfect cells to wild-type cells) of 9.7 ± 0.3, and a Michaelis-Menten constant (K_m) of 13.5 ± 3.3 µM. However, no transport was apparent via other major hepatic uptake and renal secretory transporters, including OAT1/3/4, organic anion transporting polypeptide (OATP)1B1/1B3/2B1, sodium-taurocholate co-transporting polypeptide, organ cation transporter 1/2/3. OAT2-specific transport of NA was inhibited by ketoprofen and indomethacin (known OAT2 inhibitors) in a concentration-dependent manner. Similarly, NA uptake into primary human hepatocytes showed pH- and concentration-dependence and was subject to inhibition by specific OAT2 inhibitors. Unlike NA, NAM was not transported by the hepatic and renal solute carriers upon assessment in transfected cells, although its uptake into human hepatocytes was significantly inhibited by excess unlabelled NAM and a pan-SLC inhibitor (rifamycin SV 1 mM). In conclusion, these studies demonstrate, for the first time, a specific transport mechanism for NA uptake in the human liver and suggest that OAT2 (SLC22A7) has a critical role in its physiological and pharmacological functions.

Dietary supplemental chromium and niacin influence the growth performance and fat deposition in lambs

Context Nowadays fat is an unpopular constituent of meat for consumers and therefore, a decrease in fat-tail size is often desirable for producers. Feed additives like chromium (Cr) and niacin (B3) have been reported to improve meat quality in beef and dairy cattle. However, their effect on meat quality and performance of fat-tail breeds of finishing lambs is unknown. Aim The aim of this study was to investigate the effect of supplemental chromium (Cr) and niacin (B3) on performance and fat deposition of carcass of finishing lambs. Methods Twenty male Zandi lambs (23.7 ± 0.73 kg) were allocated into one of four treatments: (1) control; (2) 300 µg/ kg DM Cr as chromium methionine; (3) 200 mg/kg DM B3 as rumen-protected niacin; and (4) 300 µg/ kg DM Cr as chromium methionine + 200 mg/kg DM B3 as rumen-protected niacin. Key results Chromium and B3 supplementation decreased blood glucose, insulin, triglycerides and low-density lipoprotein levels (P &lt; 0.05). Lambs fed diet supplemented with B3 consumed more feed with a higher growth (P &lt; 0.05) compared with other groups. There were no significant differences in feed efficiency, hot carcass weight, and dressing percentage among experimental groups. However, there was a decrease in the subcutaneous, abdominal, tail and total carcass fat in Cr supplemented lambs (P &lt; 0.01) compared with other experimental groups. The expression level of acetyl CoA carboxylase 1 (ACC1) and diglyceride acyltransferase 2 (DGAT2) genes was lower in Cr groups of lambs compared with other groups (P &lt; 0.05). Conclusions These results indicated that organic Cr supplementation improved meat quality by reducing fat accumulation, whereas B3 supplementation resulted in higher growth rate and feed intake. Implications Results showed that chromium supplementation reduces expression level of acetyl CoA carboxylase 1 and diglyceride acyltransferase 2 genes resulting in lower level of subcutaneous, abdominal, tail and total carcass fat of finishing lambs.

Discovery of a novel niacin-lipoic acid dimer N2L attenuating atherosclerosis and dyslipidemia with non-flushing effects

Niacin has been widely used as an antihyperlipidemic drug, but the flushing effect restricted its clinical application. Here, we developed novel niacin-lipoic acid dimers which lead to better lipid modulation, higher synergistic effects and less side effects. We utilized molecular docking simulation to design a novel series of niacin-lipoic acid dimers. The compound N-(2-(5-(1,2-dithiolan-3-yl)pentanamido)ethyl)nicotinamide (N2L) was selected for the in vitro and in vivo evaluation, including the agonist activity in CHO-hGPR109A cells, cell protective effects in HT22 and HUVECs cells, flushing effect in guinea pigs and rats, lipid modulation in C57BL/6 mice and high fat diet-rats and atherosclerotic lesions regulation in apolipoprotein E null mice. N2L worked as potent and selective agonists for the high affinity niacin receptor GPR109A. N2L retained antioxidation and cytoprotection of lipoic acid. In addition, N2L displayed a good therapeutic index regarding lipid modulation and atherosclerotic lesions regulation, and minimized niacin-induced vasodilation (flushing) effect in vivo. N2L showed effective treatment regarding to lipid regulation and atherosclerosis inhibition effects, also with excellent antioxidant effects, safety profiles and non-flushing. All these results suggest N2L promising application prospects in the drug development for the treatment of atherosclerosis.

A Randomized, Placebo-Controlled Trial to Assess the Effects of 8 Weeks of Administration of GSK256073, a Selective GPR109A Agonist, on High-Density Lipoprotein Cholesterol in Subjects With Dyslipidemia

GPR109A (HM74A), a G-protein-coupled receptor, is hypothesized to mediate lipid and lipoprotein changes and dermal flushing associated with niacin administration. GSK256073 (8-chloro-3-pentyl-1H-purine-2,6[3H,7H]-dione) is a selective GPR109A agonist shown to suppress fatty acid levels and produce mild flushing in short-term clinical studies. This study evaluated the effects of GSK256073 on lipids in subjects with low high-density lipoprotein cholesterol (HDLc). Subjects (n = 80) were randomized (1:1:1:1) to receive GSK256073 5, 50, or 150 mg/day or matching placebo for 8 weeks. The primary end point was determining the GSK256073 exposure-response relationship for change from baseline in HDLc. No significant exposure response was observed between GSK256073 and HDLc levels. GSK256073 did not significantly alter HDLc levels versus placebo, but rather revealed a trend at the 150-mg dose for a nonsignificant decrease in HDLc (-6.31%; P = .12) and an increase in triglycerides (median, 24.4%; 95% confidence interval, 7.3%-41.6%). Flushing was reported in 21%, 25%, and 60% of subjects (5, 50, and 150 mg, respectively) versus 24% for placebo. Results indicated that selective activation of the GPR109A receptor with GSK256073 did not produce niacin-like lipid effects. These findings add to the increasing evidence that niacin-mediated lipoprotein changes occur predominantly via GPR109A-independent pathways.

Role of endothelial NAD+ deficiency in age-related vascular dysfunction

Age-related alterations in endothelium and the resulting vascular dysfunction critically contribute to a range of pathological conditions associated with old age. To develop therapies rationally that improve vascular health and thereby increase health span and life span in older adults, it will be essential to understand the cellular and molecular mechanisms contributing to vascular aging. Preclinical studies in model organisms demonstrate that NAD+ availability decreases with age in multiple tissues and that supplemental NAD+ precursors can ameliorate many age-related cellular impairments. Here, we provide a comprehensive overview of NAD+-dependent pathways [including the NAD+-using silent information regulator-2-like enzymes and poly(ADP-ribose) polymerase enzymes] and the potential consequences of endothelial NAD+ deficiency in vascular aging. The multifaceted vasoprotective effects of treatments that reverse the age-related decline in cellular NAD+ levels, as well as their potential limitations, are discussed. The preventive and therapeutic potential of NAD+ intermediates as effective, clinically relevant interventions in older adults at risk for ischemic heart disease, vascular cognitive impairment, and other common geriatric conditions and diseases that involve vascular pathologies (e.g., sarcopenia, frailty) are critically discussed. We propose that NAD+ precursors [e.g., nicotinamide (Nam) riboside, Nam mononucleotide, niacin] should be considered as critical components of combination therapies to slow the vascular aging process and increase cardiovascular health span.

Current pharmacotherapeutic options for primary dyslipidemia in adults

INTRODUCTION

Atherosclerotic cardiovascular disease (ASCVD) and its clinical manifestations, remain a leading cause of death and disability worldwide. One of the major risk factors of ASCVD is dyslipidemia and all the available guidelines suggest the importance of strategies for lipid control in a remarkable proportion of the general population.

AREAS COVERED

This review focuses on the therapeutic options available for the management of lipid disorders in adults.

EXPERT OPINION

A large body of evidence supports that statins are still the first-line option for the management of hypercholesterolemia in a large percentage of patients. Statins should be given at the appropriate dose and considering the differences in lipid-lowering potency across the different medications. The main current challenge in the treatment of lipid disorders is the need of improving patient adherence and persistence to lipid-lowering treatments beyond the drug choice and the target lipid component. To achieve this goal, the best strategy would be to treat the patients by using the appropriate drugs given at adequate doses to reach the treatment target. We should also avoid drug interactions, monitor possible untoward side effects and promote adherence to treatment by tailoring treatment strategies to each patient.

Potential of Colocasia leaves in human nutrition: Review on nutritional and phytochemical properties

Colocasia esculenta leaves possess vital nutritive and nonnutritive components in significant amounts, but are underutilized, and lesser explored. The chemical composition varies significantly depending upon climatic conditions and other agronomical factors of the location of cultivation and variety. Micronutrients, viz. iron (3.4-11.7 mg 100 g^-1 ), copper (0.29-0.8 mg 100 g^-1 ), magnesium (170-752 mg 100 g^-1 ), potassium (0.4-2.4 g 100 g^-1 ), and zinc (0.6-4.2 mg 100 g^-1 ) are present in high amounts. The ratio of sodium to potassium (1:40) in the leaves add specifically to the antihypertensive properties. Preclinical and clinical studies provide evidence of its antidiabetic, antihemorrhagic, neuropharmacological properties, and as a remedy for stomach and liver ailments. Assessment of phytochemical compounds like chlorogenic acid, anthraquinones, cinnamic acid derivatives, and other phenolics validates these biological properties. The major limiting factor of this plant is oxalate that can be suppressed through food processing strategies. Colocasia leaves are promising green leafy vegetables with nutritional and clinical potential. PRACTICAL APPLICATIONS: Colocasia leaves have demonstrated the ability of antidiabetic, antihypertensive, immunoprotective, neuroprotective, and anticarcinogenic activities. The detailed assessment of phytochemical compounds present in various extracts of the leaves shows the presence of active chemical compounds like anthraquinones, apigenin, catechins, cinnamic acid derivatives, vitexin, and isovitexin which are possibly responsible for the exhibited biological properties. Colocasia leaves are rich sources of micronutrients; however, the presence of oxalates can prohibit proper utilization of these nutrients. Various food processing strategies like soaking, cooking, and so on can significantly reduce the antinutritional content and make these nutrients available for utilization. Documentation of traditional uses and food products from Colocasia leaves show that these leaves have immense potential in the functional food product as well as drug development.

Residual cardiovascular risk among people with diabetes

Type 2 diabetes (T2D) is a growing health concern across both developed and developing countries. Cardiovascular disease (CVD) remains the major cause of increased mortality in this patient population. In recent years, effective low density lipoprotein lowering treatments and other risk reduction strategies have substantially reduced the risk of atherosclerotic CVD, yet patients with T2D continue to remain at increased risk for atherosclerotic CVD. Here, we will briefly review various proposed underlying mechanisms for this residual risk with a more in-depth focus on the potential role of triglyceride-rich lipoproteins in residual risk and potential avenues to target this pharmacologically.

New Frontiers in Lp(a)-Targeted Therapies

Interest in lipoprotein (a) [Lp(a)] has exploded over the past decade with the emergence of genetic and epidemiological studies pinpointing elevated levels of this unique lipoprotein as a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease (CAVD). This review summarizes the most recent discoveries regarding therapeutic approaches to lower Lp(a) and presents these findings in the context of an emerging, although far from complete, understanding of the biosynthesis and catabolism of Lp(a). Application of Lp(a)-specific lowering agents to outcome trials will be the key to opening this new frontier in the battle against CVD.

Role of Nicotinamide Adenine Dinucleotide and Related Precursors as Therapeutic Targets for Age-Related Degenerative Diseases: Rationale, Biochemistry, Pharmacokinetics, and Outcomes

Significance: Nicotinamide adenine dinucleotide (NAD+) is an essential pyridine nucleotide that serves as an essential cofactor and substrate for a number of critical cellular processes involved in oxidative phosphorylation and ATP production, DNA repair, epigenetically modulated gene expression, intracellular calcium signaling, and immunological functions. NAD+ depletion may occur in response to either excessive DNA damage due to free radical or ultraviolet attack, resulting in significant poly(ADP-ribose) polymerase (PARP) activation and a high turnover and subsequent depletion of NAD+, and/or chronic immune activation and inflammatory cytokine production resulting in accelerated CD38 activity and decline in NAD+ levels. Recent studies have shown that enhancing NAD+ levels can profoundly reduce oxidative cell damage in catabolic tissue, including the brain. Therefore, promotion of intracellular NAD+ anabolism represents a promising therapeutic strategy for age-associated degenerative diseases in general, and is essential to the effective realization of multiple benefits of healthy sirtuin activity. The kynurenine pathway represents the de novo NAD+ synthesis pathway in mammalian cells. NAD+ can also be produced by the NAD+ salvage pathway. Recent Advances: In this review, we describe and discuss recent insights regarding the efficacy and benefits of the NAD+ precursors, nicotinamide (NAM), nicotinic acid (NA), nicotinamide riboside (NR), and nicotinamide mononucleotide (NMN), in attenuating NAD+ decline in degenerative disease states and physiological aging. Critical Issues: Results obtained in recent years have shown that NAD+ precursors can play important protective roles in several diseases. However, in some cases, these precursors may vary in their ability to enhance NAD+ synthesis via their location in the NAD+ anabolic pathway. Increased synthesis of NAD+ promotes protective cell responses, further demonstrating that NAD+ is a regulatory molecule associated with several biochemical pathways. Future Directions: In the next few years, the refinement of personalized therapy for the use of NAD+ precursors and improved detection methodologies allowing the administration of specific NAD+ precursors in the context of patients' NAD+ levels will lead to a better understanding of the therapeutic role of NAD+ precursors in human diseases.

Effect of dietary niacin supplementation on performance, total tract nutrient retention, carcass yield and meat lipid profile of growing turkeys

A study was conducted to investigate the influence of dietary high or recommended nicotinic acid (niacin) supplementation on growth performance, total tract nutrient digestibility, hematology, serum chemistry, and lipoprotein concentrations in the serum and meat of growing turkeys. Turkeys were assigned to three treatments on weight equalisation basis with five replicates of eight turkeys in each group. Experimental diets were: no supplemental niacin (Control), a diet supplemented with 60 mg/kg niacin termed as recommended niacin supplementation and a diet supplemented with 180 mg/kg niacin termed as high niacin supplementation (HNS). The experiment lasted for the grower (Day 56–84) and finisher phases (Day 84–112) of the birds. Dietary inclusion of HNS increased (P &lt; 0.01) bodyweight gain, metabolisable energy (Days 84 and 112), dressing percentage and retail cut parts of turkeys (Day 112) in relation to the Control-fed turkeys. Furthermore, least white blood cell count and higher concentrations of packed cell volume, red blood cells and hemoglobin (P &lt; 0.01) were found in turkeys fed HNS on Days 84 and 112. Similarly, turkeys in the HNS group had improved serum constituents including serum protein, uric acid, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphate. The blood and meat lipid profile analysis showed that low density lipoprotein and total cholesterol were least (P &lt; 0.05) in turkeys fed HNS. Collectively, dietary high supplementation of niacin (180 mg/kg) improves production performances, reduces serum and meat fat content and improve indicators of stress resistance ability in growing turkeys.

Effect of Dietary Niacin Supplementation on Growth Performance, Nutrient Digestibility, Hematology, and Lipoprotein Concentrations of Young Turkeys, Meleagris gallopavo

The growth performance, nutrient digestibility, hematology, serum chemistry, and lipoprotein concentrations of turkey (Meleagris gallopavo) poults fed diets supplemented with high or recommended concentrations of niacin were investigated in this study. A total of 120 four-week-old turkey poults were randomly divided into three treatment groups with five replicates of eight birds in each group. The poult diets were supplemented with 0.0, 60, and 180 mg/kg niacin in the three treatments, termed control, recommended niacin supplementation (RNS), and high niacin supplementation (HNS), respectively. The study lasted for four weeks. The results showed that the HNS treatment reduced the feed intake and increased the body weight gain of poults. The apparent, nitrogen-corrected, and true metabolizable energy contents were the highest in the HNS-group turkey poults (P<0.05). The red and white blood cell counts and hemoglobin concentration of the turkeys improved with increasing niacin supplementation (P<0.01). The serum constituents, including the serum protein and globulin, were significantly increased (P<0.05), while the uric acid and creatinine contents were significantly reduced in the HNS-group turkeys. Similarly, the HNS-group turkeys exhibited significantly reduced alanine aminotransferase (ALT) and alkaline phosphatase (ALP) contents, while the RNS-group turkeys had the least aspartate aminotransferase (AST) content. In addition, the HNS-group turkeys had the least serum low-density lipoprotein (LDL), triglyceride, and total cholesterol concentrations and the highest serum high-density lipoprotein (HDL) (P<0.01) concentrations. In conclusion, the supplementation of 180 mg/kg niacin in the diet reduced the feed intake and serum ALT, ALP, LDL, triglyceride, and cholesterol contents and increased the body weight gain, metabolizable energy, and HDL concentration in turkeys. This study showed that niacin supplementation could reduce the fat content without compromising the body weight gain and increase stress resistance in turkey poults.

Metabolomics activity screening for identifying metabolites that modulate phenotype

Metabolomics, in which small-molecule metabolites (the metabolome) are identified and quantified, is broadly acknowledged to be the omics discipline that is closest to the phenotype. Although appreciated for its role in biomarker discovery programs, metabolomics can also be used to identify metabolites that could alter a cell's or an organism's phenotype. Metabolomics activity screening (MAS) as described here integrates metabolomics data with metabolic pathways and systems biology information, including proteomics and transcriptomics data, to produce a set of endogenous metabolites that can be tested for functionality in altering phenotypes. A growing literature reports the use of metabolites to modulate diverse processes, such as stem cell differentiation, oligodendrocyte maturation, insulin signaling, T-cell survival and macrophage immune responses. This opens up the possibility of identifying and applying metabolites to affect phenotypes. Unlike genes or proteins, metabolites are often readily available, which means that MAS is broadly amenable to high-throughput screening of virtually any biological system.

Impact of lipid-lowering therapy on glycemic control and the risk for new-onset diabetes mellitus

Lipid-lowering therapy is used very commonly nowadays not only for the optimization of the lipid profile but also to reduce cardiovascular risk. However, some studies have linked the use of certain lipid-lowering agents with an increased risk for impaired glycemic control and new-onset diabetes mellitus, a condition well established as an important risk factor for cardiovascular disease. On the other hand, some other lipid-lowering agents have been shown to have a beneficial effect on glucose metabolism. Profound knowledge of these differences would enable the clinician to choose the right lipid-lowering medication for each individual patient, so that the benefits would outweigh the risk of side effects. This review aims to present and discuss the clinical and scientific data pertaining to the impact of lipid-lowering therapy on glycemic control and the risk for new-onset diabetes mellitus.

Dyslipidemia in pregnancy and maternal-fetal outcome

Hyperlipidemia is a known cause of atherosclerosis and directly contributes to the current epidemic in cardio-vascular disease. Pregnancy is typified by an increase in serum levels of total cholesterol and triglycerides pushed by the rise in estrogen, progesterone and lactogen. Mobilization of stored fat depots in late pregnancy may provide a reservoir of fatty acids for fetal growth and placental tissue steroid synthesis. This physiologic increase in lipids performs an essential role during pregnancy; however, elevated levels of lipids in predisposed women or with familiar forms of hyperlipidemia can carry increased risk for maternal-fetal complications. The present treatment of pregnant women with hyperlipidemia is the suspension of medications. However, hyperlipidemia during pregnancy is associated with preeclampsia, preterm birth and gestational diabetes and offspring of these mothers show a propensity to enhanced fatty streak formation and an increased risk of progressive atherosclerosis. This current evidence may motivate the further study on the potential benefits of treatment of hyperlipidemia in pregnancy and its effects on maternal-fetal outcomes.