Comparison of the activity and disposition of the novel cholesterol absorption inhibitor, SCH58235, and its glucuronide, SCH60663

The Role of Small Molecules Containing Fluorine Atoms in Medicine and Imaging Applications

The fluorine atom possesses many intrinsic properties that can be beneficial when incorporated into small molecules. These properties include the atom's size, electronegativity, and ability to block metabolic oxidation sites. Substituents that feature fluorine and fluorine-containing groups are currently prevalent in drugs that lower cholesterol, relieve asthma, and treat anxiety disorders, as well as improve the chemical properties of various medications and imaging agents. The dye scaffolds (fluorescein/rhodamine, coumarin, BODIPY, carbocyanine, and squaraine dyes) reported will address the incorporation of the fluorine atom in the scaffold and the contribution it provides to its application as an imaging agent. It is also important to recognize radiolabeled fluorine atoms used for PET imaging in the early detection of diseases. This review will discuss the many benefits of incorporating fluorine atoms into small molecules and give examples of fluorinated molecules used in the pharmaceutical industry and imaging techniques.

Bioequivalence Study of Ezetimibe Tablets After a Single Oral Dose of 10 mg in Healthy Japanese Subjects Under Fasting Conditions

This study compared the pharmacokinetic and safety profiles between a new generic and a branded reference product of 10-mg ezetimibe (EZE) tablets in 24 healthy Japanese male volunteers under fasting conditions, obtaining sufficient evidence for the marketing approval of the new generic product. The bioequivalence study was conducted with an open-label, 2 × 2, single-dose, crossover design in which the test and reference products were administered to volunteers after fasting for ≥10 hours. Blood samples were collected 24 times before to 72 hours after the administration of the investigational drug. We evaluated the peak drug concentration and the area under the plasma concentration-time curve up to the last measured concentration of EZE, EZEG, and total EZE (EZE + ezetimibe glucuronide [EZEG]). The 90% confidence intervals of the geometric mean ratios for peak drug concentration and area under the plasma concentration-time curve up to the last measured concentration of the test and reference products fell within the bioequivalence limits of 0.80 to 1.25 for EZE, EZEG, and total EZE. The test and reference products were well tolerated, and no adverse events occurred during the study. The test product was bioequivalent to the reference product.

The Prevalence of Several Treatments in Preventing the Back Conversion of Acyl Glucuronide Metabolites in Abbreviated New Drug Applications

The bioanalysis of drugs that undergo acyl glucuronidation presents an analytical challenge due to poor stability of acyl glucuronide metabolites in biological matrices. The objective of this study was to investigate the impact of back conversion of acyl glucuronide metabolites on drug concentration measurement in bioequivalence (BE) studies submitted to Abbreviated New Drug Applications (ANDAs). The prevalence of several treatments for preventing the back conversion of acyl glucuronide metabolites and the results of incurred sample reanalysis (ISR) were analyzed. In total, 322 ANDAs for 26 drugs known to generate acyl glucuronide metabolites were surveyed. Many studies have applied multiple preventive treatments during the clinical and bioanalytical phases. More than two-thirds (67.2%) of the studies utilized procedures of lowering the temperature for sample collection during clinical phase. Fewer studies have utilized procedures for lowering the pH of plasma samples (12.3%) or adding enzyme inhibitors (4.4%) in the clinical phase. A small fraction (16.9%) validated the pre-study method in the presence of the acyl glucuronide metabolites. The majority (62.2%) of the studies employed the procedure of lowering the pH during the sample extraction process in the bioanalytical phase. Among the studies that had significantly higher (p-value < 0.01 by sign test) ISR results than the corresponding original concentration values, 41 BE studies did not carry out any preventive treatments during the bioanalysis phase, suggesting that back conversion of acyl glucuronide metabolites to parent drugs may be present in these studies. The awareness of appropriate treatments of study samples for possible back-conversions of acyl glucuronide metabolites is expected to assist generic drug applicants in improving the quality of their future applications.

Changes in Disposition of Ezetimibe and Its Active Metabolites Induced by Impaired Hepatic Function: The Influence of Enzyme and Transporter Activities

Ezetimibe (EZE) is a selective cholesterol absorption inhibitor. Hepatic impairment significantly increases the systemic exposure of EZE and its main active phenolic glucuronide, EZE-Ph. Although changes in efflux transporter activity partly explain the changes in EZE-Ph pharmacokinetics, the causes of the changes to EZE and the effects of the administration route on EZE-Ph remain unclear. A carbon tetrachloride (CCl₄)-induced hepatic failure rat model was combined with in vitro experiments to explore altered EZE and EZE-Ph disposition caused by hepatic impairment. The plasma exposure of EZE and EZE-Ph increased by 11.1- and 4.4-fold in CCl₄-induced rats following an oral administration of 10 mg/kg EZE, and by 2.1- and 16.4-fold after an intravenous injection. The conversion of EZE to EZE-Ph decreased concentration-dependently in CCl₄-induced rat liver S9 fractions, but no change was observed in the intestinal metabolism. EZE-Ph was a substrate for multiple efflux and uptake transporters, unlike EZE. In contrast to efflux transporters, no difference was seen in the hepatic uptake of EZE-Ph between control and CCl₄-induced rats. However, bile acids that accumulated due to liver injury inhibited the uptake of EZE-Ph by organic anion transporting polypeptides (OATPs) (glycochenodeoxycholic acid and taurochenodeoxycholic acid had IC₅₀ values of 15.1 and 7.94 μM in OATP1B3-overexpressed cells). In conclusion, the increased plasma exposure of the parent drug EZE during hepatic dysfunction was attributed to decreased hepatic glucuronide conjugation, whereas the increased exposure of the metabolite EZE-Ph was mainly related to transporter activity, particularly the inhibitory effects of bile acids on OATPs after oral administration.

Pharmacogenomics of lipid-lowering agents: the impact on efficacy and safety

Hyperlipidemia is a significant risk factor for cardiovascular disease morbidity and mortality. The lipid-lowering drugs are considered the cornerstone of primary and secondary prevention of atherosclerotic cardiovascular disease. Unfortunately, the lack of efficacy and associated adverse effects, ranging from mild-to-moderate to potentially life-threatening, lead to therapy discontinuation. Numerous reports support the role of gene polymorphisms in drugs' pharmacokinetic parameters and their associated adverse reactions. Therefore, this study aims to understand the pharmacogenomics of lipid-lowering drugs and the impact of genetic variants of key genes on the drugs' efficacy and toxicity. Indeed, genetically guided lipid-lowering therapy enhances overall safety, improves drug adherence and achieves long-term therapy.

Ezetimibe and Cancer: Is There a Connection?

The high level of serum cholesterol caused by the excessive absorption of cholesterol can lead to hypercholesteremia, thus promoting the occurrence and development of cancer. Ezetimibe is a drug that reduces cholesterol absorption and has been widely used for the treatment of patients with high circulating cholesterol levels for many years. Mechanistically, ezetimibe works by binding to NPC1L1, which is a key mediator of cholesterol absorption. Accumulating data from preclinical models have shown that ezetimibe alone could inhibit the development and progression of cancer through a variety of mechanisms, including anti-angiogenesis, stem cell suppression, anti-inflammation, immune enhancement and anti-proliferation. In the past decade, there has been heated discussion on whether ezetimibe combined with statins will increase the risk of cancer. At present, more and more evidence shows that ezetimibe does not increase the risk of cancers, which supports the role of ezetimibe in anti-cancer. In this review, we discussed the latest progress in the anti-cancer properties of ezetimibe and elucidated its underlying molecular mechanisms. Finally, we highlighted the potential of ezetimibe as a therapeutic agent in future cancer treatment and prevention.

Monosaccharide induced temporal delay in cholesterol self-aggregation

Self-assembly of cholesterol (CHL) is infamous for its diverse deleterious effects on human health. Clinical research over several decades indicates that a diet rich in CHL typically leads to arterial plaques, cataracts and gall stones among others. Carbohydrates like the β-glucans efficiently lower serum CHL, possibly by inhibiting CHL absorption in the digestive tract. Using molecular dynamics simulations, we explore how β-D-glucose (BGLC), the building block of β-glucans, interferes with CHL aggregation. BGLC slows down CHL diffusion and disrupts the formation of the robust hydrophobic CHL assembly. Estimation of the translational entropy of the CHL molecules shows the extent of retardation induced by BGLC. Coordination numbers obtained from the adjacency matrix and collective variable analysis of the packing of the CHL molecules in presence of BGLC show the time evolution of CHL aggregation. In presence of BGLC, small isolated CHL islands form, consolidate and disintegrate over time as compared to the blank CHL system. The predominance of smaller CHL clusters is an effect of the significant retardation of the translational motion of CHL molecules induced by BGLC.Communicated by Ramaswamy H. Sarma.

Emerging Non-statin Treatment Options for Lowering Low-Density Lipoprotein Cholesterol

Low-density lipoprotein cholesterol (LDL-C) is a modifiable risk factor for the development of atherosclerotic cardiovascular disease. Statins have been the gold standard for managing cholesterol levels and reducing the risks associated with atherosclerotic cardiovascular disease; however, many patients do not achieve their cholesterol goals or are unable to tolerate this drug class due to adverse drug events. Recent studies of non-statin cholesterol lowering drugs (i.e., ezetimibe, PCSK9 inhibitors) have demonstrated cardiovascular benefits; and new drugs [i.e., bempedoic acid (BDA), inclisiran] have produced promising results in pre-clinical and clinical outcome trials. This narrative review aims to discuss the place in therapy of ezetimibe, PCSK9 inhibitors, BDA, and inclisiran and describe their relative pharmacokinetic (PK) profiles, efficacy and safety as monotherapy and combination therapy, and cardiovascular benefit(s) when used for hypercholesterolemia.

Effectiveness and Safety of Lipid-Lowering Drug Treatments in Japanese Patients with Familial Hypercholesterolemia: Familial Hypercholesterolemia Expert Forum (FAME) Study

Aims: Familial hypercholesterolemia (FH) is a genetic disorder characterized by high serum levels of low-density lipoprotein (LDL)-cholesterol (LDL-C), tendon and skin xanthomas, and premature coronary artery disease (CAD). In Japan, detailed information on the current status of drug therapies for patients with FH has not been reported so far, and their efficacy and safety have not been clarified. After the introduction of ezetimibe, which can further reduce serum LDL-C levels on top of statins, the changes of management for FH patients with these drugs are of particular interest. The current study aimed to evaluate the clinical status of FH heterozygotes and homozygotes, especially focusing on the real-world lipid-lowering drug therapy, attained serum LDL-C levels, and cardiovascular events at registration and during the follow-up.

Methods: The FAME Study enrolled 762 heterozygous (including 17 newly diagnosed cases) and 7 homozygous FH patients from hospitals and clinics nationwide. Diagnosis of FH was based upon the criteria defined in the Study Report in 2008 of the Research Committee on Primary Hyperlipidemia supported by Grants-in-Aid for Scientific Research from the Japanese Ministry of Health, Labor and Welfare. Data analysis was primarily carried on heterozygous FH patients.

Results: Xanthoma or thickening of the Achilles tendon was observed in more than 80% of the patients. CAD was recorded in 23% of patients. Patients with parental and sibling CAD accounted for 47% and 24%, respectively. At baseline, patients without CAD who had LDL-C ＜100 mg/dL accounted for 12.3% and those with CAD who had attained the target (LDL-C ＜70 mg/dL) in the secondary prevention accounted for only 1.8%. In the multiple logistic analysis, male sex, age ＞40, heterozygous FH score ＞20, hypertension, and sibling CAD were significantly and positively associated with prevalent CAD, whereas serum HDL-cholesterol levels showed a significant inverse association with CAD. Patients treated with statin alone, statin＋ezetimibe, statin＋resin, or statin＋probucol accounted for 31.1%, 26.3%, 4.0%, and 3.7%, respectively. Patients treated with three-drug combination (statin＋ezetimibe＋resin or statin＋ezetimibe＋probucol) accounted for 7.5%. Statins and ezetimibe were used in 88.0% and 48.0% at the baseline, respectively. Although high-intensity statins were mainly prescribed, statin doses were much lower than those reported in Western countries. The addition of ezetimibe resulted in ~20% reduction in serum LDL-C. CAD was diagnosed in 17 patients with 21 episodes during follow-up. The Cox hazard model analysis demonstrated that male sex, CAD at the baseline, and parental CAD were related to the development of atherosclerotic cardiovascular disease (ASCVD) events. Furthermore, an increase in serum HDL-C was associated with a significant reduction of ASCVD events, while serum LDL-C and triglyceride levels were not related to ASCVD events.

Conclusion: The prevalence of CAD in Japanese patients with heterozygous FH is still very high. In most of the cases, the target level of serum LDL-C was not achieved for primary and secondary prevention of CAD, suggesting that a more aggressive LDL-C lowering and appropriate management of residual risks are necessary.

Tailor-made amino acids in the design of small-molecule blockbuster drugs

The role of amino acids (AAs) in modern health industry is well-appreciated. Residues of individual AAs, or their chemical modifications, such as diamines and amino alcohols, are frequently found in the structures of modern pharmaceuticals. The goal of this review article, is to emphasize that, currently, tailor-made AAs serve as key structural features in many most successful pharmaceuticals, so-called blockbuster drugs. In the present article, we profile 14 small-molecule drugs, underscoring the breadth of structural variety of AAs applications in numerous therapeutic areas. For each compound, we provide spectrum of biological activity, medicinal chemistry discovery, and synthetic approaches.

Inhibition of Intestinal Lipid Absorption by Cyanobacterial Strains in Zebrafish Larvae

Obesity is a complex metabolic disease, which is increasing worldwide. The reduction of dietary lipid intake is considered an interesting pathway to reduce fat absorption and to affect the chronic energy imbalance. In this study, zebrafish larvae were used to analyze effects of cyanobacteria on intestinal lipid absorption in vivo. In total, 263 fractions of a cyanobacterial library were screened for PED6 activity, a fluorescent reporter of intestinal lipases, and 11 fractions reduced PED6 activity > 30%. Toxicity was not observed for those fractions, considering mortality, malformations or digestive physiology (protease inhibition). Intestinal long-chain fatty acid uptake (C16) was reduced, but not short-chain fatty acid uptake (C5). Alteration of lipid classes by high-performance thin-layer chromatography (HPTLC) or lipid processing by fluorescent HPTLC was analyzed, and 2 fractions significantly reduced the whole-body triglyceride level. Bioactivity-guided feature-based molecular networking of LC-MS/MS data identified 14 significant bioactive mass peaks (p < 0.01, correlation > 0.95), which consisted of 3 known putative and 11 unknown compounds. All putatively identified compounds were known to be involved in lipid metabolism and obesity. Summarizing, some cyanobacterial strains repressed intestinal lipid absorption without any signs of toxicity and could be developed in the future as nutraceuticals to combat obesity.

Pharmacokinetic Interaction Among Ezetimibe, Rosuvastatin, and Telmisartan

To evaluate the pharmacokinetic interactions among rosuvastatin, ezetimibe, and telmisartan, a randomized, open-label, 3-period, 6-sequence crossover study was conducted in healthy subjects. Subjects received one of the following treatments once daily for 7 days in each period with a 1-week washout: a fixed-dose combination of ezetimibe/rosuvastatin 10/20 mg, telmisartan 80 mg, combination therapy of ezetimibe/rosuvastatin 10/20 mg, or telmisartan 80 mg. Blood samples were collected up to 24 hours postdose at steady state. Geometric mean ratios (GMRs) and their 90% confidence intervals (CIs) of the combination therapy to monotherapy for the maximum plasma concentration (C_max,ss ), and the area under the time-concentration curve within a dosing interval at steady state (AUC_tau,ss ) were estimated. Among the 36 randomized subjects, 31 subjects completed the study. The GMRs and 90%CIs of C_max,ss and AUC_tau,ss of total ezetimibe were not significantly altered. The C_max,ss of free ezetimibe was increased (GMR, 1.85; 90%CI, 1.56-2.19) but not for the AUC_tau,ss (GMR, 1.16; 90%CI, 1.06-1.26). Similarly, the C_max,ss of rosuvastatin was increased (GMR, 2.13; 90%CI, 1.88-2.43) without a change in the AUC_tau,ss (GMR, 1.09; 90%CI, 1.03-1.15). The C_max,ss (GMR, 1.16; 90%CI, 1.01-1.32) and AUC_tau,ss (GMR, 1.26; 90%CI, 1.17-1.37) of telmisartan were slightly increased. Considering the therapeutic range of the components, the interaction would have limited clinical impact.

Induction of fecal cholesterol excretion is not effective for the treatment of hyperbilirubinemia in Gunn rats

BACKGROUND

Unconjugated hyperbilirubinemia, a feature of neonatal jaundice or Crigler-Najjar syndrome, can lead to neurotoxicity and even death. We previously demonstrated that unconjugated bilirubin (UCB) can be eliminated via transintestinal excretion in Gunn rats, a model of unconjugated hyperbilirubinemia, and that this is stimulated by enhancing fecal fatty acid excretion. Since transintestinal excretion also occurs for cholesterol (TICE), we hypothesized that increasing fecal cholesterol excretion and/or TICE could also enhance fecal UCB disposal and subsequently lower plasma UCB concentrations.

METHODS

To determine whether increasing fecal cholesterol excretion could ameliorate unconjugated hyperbilirubinemia, we treated hyperbilirubinemic Gunn rats with ezetimibe (EZE), an intestinal cholesterol absorption inhibitor, and/or a liver X receptor (LXR) and farnesoid X receptor (FXR) agonist (T0901317 (T09) and obeticholic acid (OCA), respectively), known to stimulate TICE.

RESULTS

We found that EZE treatment alone or in combination with T09 or OCA increased fecal cholesterol disposal but did not lower plasma UCB levels.

CONCLUSIONS

These findings do not support a link between the regulation of transintestinal excretion of cholesterol and bilirubin. Furthermore, induction of fecal cholesterol excretion is not a potential therapy for unconjugated hyperbilirubinemia.

IMPACT

Increasing fecal cholesterol excretion is not effective to treat unconjugated hyperbilirubinemia. This is the first time a potential relation between transintestinal excretion of cholesterol and unconjugated bilirubin is investigated. Transintestinal excretion of cholesterol and unconjugated bilirubin do not seem to be quantitatively linked. Unlike intestinal fatty acids, cholesterol cannot "capture" unconjugated bilirubin to increase its excretion. These results add to our understanding of ways to improve and factors regulating unconjugated bilirubin disposal in hyperbilirubinemic conditions.

Enzyme Kinetics of Uridine Diphosphate Glucuronosyltransferases (UGTs)

Glucuronidation, catalyzed by uridine diphosphate glucuronosyltransferases (UGTs), is an important process for the metabolism and clearance of many lipophilic chemicals, including drugs, environmental chemicals, and endogenous compounds. Glucuronidation is a bisubstrate reaction that requires the aglycone and the cofactor, UDP-GlcUA. Accumulating evidence suggests that the bisubstrate reaction follows a compulsory-order ternary mechanism. To simplify the kinetic modeling of glucuronidation reactions in vitro, UDP-GlcUA is usually added to incubations in large excess. Many factors have been shown to influence UGT activity and kinetics in vitro, and these must be accounted for during experimental design and data interpretation. While the assessment of drug-drug interactions resulting from UGT inhibition has been challenging in the past, the increasing availability of UGT enzyme-selective substrate and inhibitor "probes" provides the prospect for more reliable reaction phenotyping and assessment of drug-drug interaction potential. Although extrapolation of the in vitro intrinsic clearance of a glucuronidated drug often underpredicts in vivo clearance, careful selection of in vitro experimental conditions and inclusion of extrahepatic glucuronidation may improve the predictivity of in vitro-in vivo extrapolation. Physiologically based pharmacokinetic (PBPK) modeling has also shown to be of value for predicting PK of drugs eliminated by glucuronidation.

Transport via Niemann-Pick C1 Like 1 contributes to the intestinal absorption of ubiquinone

Ubiquinone, which is a component in the electron-transport systems of mitochondria, is essential for various activities related to energy metabolism, but the detailed absorption mechanism of ubiquinone is not clear. On the other hand, Niemann-Pick C1 Like 1 (NPC1L1) is involved in the intestinal absorption of fat-soluble components such as cholesterol. In this study, we investigated whether the intestinal absorption of ubiquinone was transported by NPC1L1 as is cholesterol. In this study, coenzyme q10 (CoQ10) and coenzyme q9 (CoQ9) were used as models of ubiquinone. The transport activity of ubiquinone was increased significantly in NPC1L1-overexpressed Madin-Darby canine kidney (MDCK) cells compared with that in pMAM2-BSD vector-transfected MDCK cells and the uptake of ubiquinone was decreased in the presence of ezetimibe, an inhibitor of NPC1L1. These results indicate that NPC1L1 mediates the transport of ubiquinone. Furthermore, to clarify the effect of NPC1L1 on the intestinal absorption of CoQ10, emulsified CoQ10 was orally administered to Wistar rats, and the plasma concentration was measured. The plasma concentration of CoQ10 was significantly decreased by coadministration of ezetimibe and CoQ10 compared to that with administration of only CoQ10. This result indicates that the intestinal absorption of CoQ10 is mediated by NPC1L1.

Inter-domain dynamics drive cholesterol transport by NPC1 and NPC1L1 proteins

Transport of LDL-derived cholesterol from lysosomes into the cytoplasm requires NPC1 protein; NPC1L1 mediates uptake of dietary cholesterol. We introduced single disulfide bonds into NPC1 and NPC1L1 to explore the importance of inter-domain dynamics in cholesterol transport. Using a sensitive method to monitor lysosomal cholesterol efflux, we found that NPC1's N-terminal domain need not release from the rest of the protein for efficient cholesterol export. Either introducing single disulfide bonds to constrain lumenal/extracellular domains or shortening a cytoplasmic loop abolishes transport activity by both NPC1 and NPC1L1. The widely prescribed cholesterol uptake inhibitor, ezetimibe, blocks NPC1L1; we show that residues that lie at the interface between NPC1L1's three extracellular domains comprise the drug's binding site. These data support a model in which cholesterol passes through the cores of NPC1/NPC1L1 proteins; concerted movement of various domains is needed for transfer and ezetimibe blocks transport by binding to multiple domains simultaneously.

In-Depth Characterization of EpiIntestinal Microtissue as a Model for Intestinal Drug Absorption and Metabolism in Human

The Caco-2 model is a well-accepted in vitro model for the estimation of fraction absorbed in human intestine. Due to the lack of cytochrome P450 3A4 (CYP3A4) activities, Caco-2 model is not suitable for the investigation of intestinal first-pass metabolism. The purpose of this study is to evaluate a new human intestine model, EpiIntestinal microtissues, as a tool for the prediction of oral absorption and metabolism of drugs in human intestine. The activities of relevant drug transporters and drug metabolizing enzymes, including MDR1 P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), CYP3A4, CYP2J2, UDP-glucuronosyltransferases (UGT), carboxylesterases (CES), etc., were detected in functional assays with selective substrates and inhibitors. Compared to Caco-2, EpiIntestinal microtissues proved to be a more holistic model for the investigation of drug absorption and metabolism in human gastrointestinal tract.

Effectiveness of black tea versus placebo in subjects with hypercholesterolemia: A PRISMA systematic review and meta-analysis

AIM

To determine if the black tea is more effective in serum lipid profile that placebo in subjects with hypercholesterolemia.

DESIGN

Systematic review with meta-analysis of randomized clinical trials (RCTs).

DATA SOURCES

The databases Medline, Central, Embase, Lilacs, Cinahl, SPORTDiscus, and Web of Science were searched from inception up to January 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

RCTs that compared black tea versus placebo, that included serum lipid profile outcomes in subjects older than 18 years of age with hypercholesterolemia.

RESULTS

Seven RCTs met the eligibility criteria, and for the quantitative synthesis, six studies were included. Mean difference for total cholesterol was 1.67 mg/dl 95% CI = -5.47 to 8.80 (p = 0.65), mean difference 0.28 mg/dl, 95% CI = -3.89 to 4.45 (p = 0.90) for triglycerides, mean difference 3.21 mg/dl, 95% CI = -11.02 to 4.60 (p = 0.42) for low density lipoprotein-cholesterol, mean difference 0.38 mg/dl, 95% CI = -1.12 to 1.87 (p = 0.62) for high density lipoprotein-cholesterol.

CONCLUSION

In the short term, no significant differences were found in lipid serum profile comparing black tea consumption with placebo.

Nonglucuronidated Ezetimibe Disrupts CD13- and CD64-Coassembly in Membrane Microdomains and Decreases Cellular Cholesterol Content in Human Monocytes/Macrophages

Ezetimibe (EZE) and glucuronidated EZE (EZE-Glu) differentially target Niemann-Pick C1-like 1 (NPC1L1) and CD13 (aminopeptidase-N) to inhibit intestinal cholesterol absorption and cholesterol processing in other cells, although the precise molecular mechanisms are not fully elucidated. Cellular effects of EZE, EZE-Glu, and the low-absorbable EZE-analogue S6130 were investigated on human monocyte-derived macrophages upon loading with atherogenic lipoproteins. EZE and S6130, but not EZE-Glu disturbed the colocalization of CD13 and its coreceptor CD64 (Fcγ receptor I) in membrane microdomains, and decreased the presence of both receptors in detergent-resistant membrane fractions. Biotinylated cholesterol absorption inhibitor C-5 (i.e., derivative of EZE) was rapidly internalized to perinuclear tubular structures of cells, resembling endoplasmic reticulum (ER), but CD13 was detected on extracellular sites of the plasma membrane and endolysosomal vesicles. Administration of EZE, but not of EZE-Glu or S6130, was associated with decreased cellular cholesteryl ester content, indicating the sterol-O acyltransferase 1 (SOAT1)-inhibition by EZE. Furthermore, EZE decreased the expression of molecules involved in cholesterol uptake and synthesis, in parallel with increased apolipoprotein A-I-mediated cholesterol efflux and upregulation of efflux-effectors. However, NPC1L1 the other claimed molecular target of EZE, was not detected in macrophages, thereby excluding this protein as target for EZE in macrophages. Thus, EZE is very likely a CD13-linked microdomain-disruptor and SOAT1-inhibitor in macrophages leading to in vitro anti-atherosclerotic effects through a decrease of net cellular cholesterol content. © 2019 International Society for Advancement of Cytometry.

The effects of green tea on lipid metabolism and its potential applications for obesity and related metabolic disorders - An existing update

Obesity is one of the top global issues, which induces several serious health consequences both physically and mentally, such as type 2 diabetes, cardiovascular diseases, dyslipidemia, eating disorders, depression and stress. However, the effective therapy to prevent and treat obesity and overweight, up to now, cannot be found nowadays. Several methods/medicines namely diet control, energy balance, environmental changes, genetic and stem cell therapies, new drugs/chemicals have been extensively studied to enhance the ability to control bodyweight and prevent obesity. Of all the aforementioned methods, green tea, used as a daily beverage, has shown beneficial impacts for the health, especially its anti-obesity effects. Available evidence shows that green tea can interrupt lipid emulsification, reduce adipocyte differentiation, increase thermogenesis, and reduce food intake, thus green tea improves the systemic metabolism and decreases fat mass. Here, we highlight and sum up the update investigations of anti-obesity effect of green tea as well as discuss the potential application of them for preventing obesity and its related metabolic disorders.

Ezetimibe for the prevention of cardiovascular disease and all-cause mortality events

BACKGROUND

Cardiovascular disease (CVD) remains an important cause of mortality and morbidity, and high levels of blood cholesterol are thought to be the major modifiable risk factors for CVD. The use of statins is the preferred treatment strategy for the prevention of CVD, but some people at high-risk for CVD are intolerant to statin therapy or unable to achieve their treatment goals with the maximal recommended doses of statin. Ezetimibe is a selective cholesterol absorption inhibitor, whether it has a positive effect on CVD events remains uncertain. Results from clinical studies are inconsistent and a thorough evaluation of its efficacy and safety for the prevention of CVD and mortality is necessary.

OBJECTIVES

To assess the efficacy and safety of ezetimibe for the prevention of CVD and all-cause mortality.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase and Web of Science on 27 June 2018, and two clinical trial registry platforms on 11 July 2018. We checked reference lists from primary studies and review articles for additional studies. No language restrictions were applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared ezetimibe versus placebo or ezetimibe plus other lipid-modifying drugs versus other lipid-modifying drugs alone in adults, with or without CVD, and which had a follow-up of at least 12 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, assessed risk of bias and contacted trialists to obtain missing data. We performed statistical analyses according to the Cochrane Handbook for Systematic Reviews of Interventions and used the GRADE to assess the quality of evidence.

MAIN RESULTS

We included 26 RCTs randomising 23,499 participants. All included studies assessed effects of ezetimibe plus other lipid-modifying drugs compared with other lipid-modifying drugs alone or plus placebo. Our findings were driven by the largest study (IMPROVE-IT), which had weights ranging from 41.5% to 98.4% in the different meta-analyses.Ezetimibe with statins probably reduces the risk of major adverse cardiovascular events compared with statins alone (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.90 to 0.98; a decrease from 284/1000 to 267/1000, 95% CI 256 to 278; 21,727 participants; 10 studies; moderate-quality evidence). Trials reporting all-cause mortality used ezetimibe with statin or fenofibrate and found they have little or no effect on this outcome (RR 0.98, 95% CI 0.91 to 1.05; 21,222 participants; 8 studies; high-quality evidence). Adding ezetimibe to statins probably reduces the risk of non-fatal myocardial infarction (MI) (RR 0.88, 95% CI 0.81 to 0.95; a decrease from 105/1000 to 92/1000, 95% CI 85 to 100; 21,145 participants; 6 studies; moderate-quality evidence) and non-fatal stroke (RR 0.83, 95% CI 0.71 to 0.97; a decrease 32/1000 to 27/1000, 95% CI 23 to 31; 21,205 participants; 6 studies; moderate-quality evidence). Trials reporting cardiovascular mortality added ezetimibe to statin or fenofibrate, probably having little or no effect on this outcome (RR 1.00, 95% CI 0.89 to 1.12; 19457 participants; 6 studies; moderate-quality evidence). The need for coronary revascularisation might be reduced by adding ezetimibe to statin (RR 0.94, 95% CI 0.89 to 0.99; a decrease from 196/1000 to 184/1000, 95% 175 to 194; 21,323 participants; 7 studies); however, no difference in coronary revascularisation rate was observed when a sensitivity analysis was limited to studies with a low risk of bias.In terms of safety, adding ezetimibe to statins may make little or no difference in the risk of hepatopathy (RR 1.14, 95% CI 0.96 to 1.35; 20,687 participants; 4 studies; low-quality evidence). It is uncertain whether ezetimibe increase or decrease the risk of myopathy (RR 1.31, 95% CI 0.72 to 2.38; 20,581 participants; 3 studies; very low-quality evidence) and rhabdomyolysis, given the wide CIs and low event rate. Little or no difference in the risk of cancer, gallbladder-related disease and discontinuation due to adverse events were observed between treatment groups. For serum lipids, adding ezetimibe to statin or fenofibrate might further reduce the low-density lipoprotein cholesterol (LDL-C), total cholesterol and triglyceride levels and likely increase the high-density lipoprotein cholesterol levels; however, substantial heterogeneity was detected in most analyses.None of the included studies reported on health-related quality of life.

AUTHORS' CONCLUSIONS

Moderate- to high-quality evidence suggests that ezetimibe has modest beneficial effects on the risk of CVD endpoints, primarily driven by a reduction in non-fatal MI and non-fatal stroke, but it has little or no effect on clinical fatal endpoints. The cardiovascular benefit of ezetimibe might involve the reduction of LDL-C, total cholesterol and triglycerides. There is insufficient evidence to determine whether ezetimibe increases the risk of adverse events due to the low and very low quality of the evidence. The evidence for beneficial effects was mainly obtained from individuals with established atherosclerotic cardiovascular disease (ASCVD, predominantly with acute coronary syndrome) administered ezetimibe plus statins. However, there is limited evidence regarding the role of ezetimibe in primary prevention and the effects of ezetimibe monotherapy in the prevention of CVD, and these topics thus requires further investigation.

Acyl Glucuronide Metabolites of 6-Chloro-5-[4-(1-hydroxycyclobutyl)phenyl]-1 H-indole-3-carboxylic Acid (PF-06409577) and Related Indole-3-carboxylic Acid Derivatives are Direct Activators of Adenosine Monophosphate-Activated Protein Kinase (AMPK)

Studies on indole-3-carboxylic acid derivatives as direct activators of human adenosine monophosphate-activated protein kinase (AMPK) α1β1γ1 isoform have culminated in the identification of PF-06409577 (1), PF-06885249 (2), and PF-06679142 (3) as potential clinical candidates. Compounds 1-3 are primarily cleared in animals and humans via glucuronidation. Herein, we describe the biosynthetic preparation, purification, and structural characterization of the glucuronide conjugates of 1-3. Spectral characterization of the purified glucuronides M1, M2, and M3 indicated that they were acyl glucuronide derivatives. In vitro pharmacological evaluation revealed that all three acyl glucuronides retained selective activation of β1-containing AMPK isoforms. Inhibition of de novo lipogenesis with representative parent carboxylic acids and their respective acyl glucuronide conjugates in human hepatocytes demonstrated their propensity to activate cellular AMPK. Cocrystallization of the AMPK α1β1γ1 isoform with 1-3 and M1-M3 provided molecular insights into the structural basis for AMPK activation by the glucuronide conjugates.

On the population pharmacokinetics and the enterohepatic recirculation of total ezetimibe

Ezetimibe is a potent cholesterol absorption inhibitor, with an erratic pharmacokinetic (PK) profile, attributed to an extensive enterohepatic recirculation (EHC). The aim of this study was to develop a population PK model able to adequately characterize the complex distribution processes of total ezetimibe. The analysis was performed on the individual concentration-time data obtained from 28 healthy subjects who participated in a bioequivalence study comparing two oral ezetimibe formulations. The population PK analysis was performed using nonlinear mixed effect modeling, where different EHC models were developed and evaluated for their performance. Total ezetimibe pharmacokinetics was best described by a four-compartment model featuring EHC through the inclusion of an additional gallbladder compartment, which was assumed to release drug at specific time-intervals consistent with food intake. The final PK model was able to adequately estimate the population pharmacokinetic parameters and to allow for a formal characterization of the pharmacokinetic profile and the secondary peaks due to enterohepatic recirculation.

Pharmacokinetic interactions and tolerability of rosuvastatin and ezetimibe: an open-label, randomized, multiple-dose, crossover study in healthy male volunteers

Purpose

Rosuvastatin is a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor that effectively reduces low-density lipoprotein cholesterol levels. However, statin monotherapy does not always achieve acceptable low-density lipoprotein cholesterol levels in patients with severe hypercholesterolemia. Ezetimibe, a selective cholesterol-absorption inhibitor, is approved for use as a monotherapy or combination therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors for patients with hypercholesterolemia. The aim of this study was to examine the pharmacokinetics (PKs) of drug interactions between rosuvastatin and ezetimibe, and the tolerability of combined administration in healthy Korean male volunteers.

Subjects and methods

Healthy subjects (n=24) were randomly allocated to 3 treatment groups: rosuvastatin (20 mg) alone, ezetimibe (10 mg) alone, and rosuvastatin (20 mg) plus ezetimibe (10 mg). The drugs were taken once every 24 hours over a period of 10 days. Blood samples were collected to analyze steady-state PKs.

Results

All adverse events observed during the study were mild, and the frequency was no higher for combined administration than for mono administration. For rosuvastatin, the steady-state mean ratios (90% CI) of the combined over the single dose were 1.076 (1.019–1.136) for AUC_τ,ss and 1.099 (1.003–1.204) for concentration at steady-state, respectively. In the case of free and total ezetimibe, the steady-state ratios of AUC_τ,ss and concentration at steady-state were 1.131 (1.051–1.218) and 1.182 (1.038–1.346), and 1.055 (0.969–1.148) and 0.996 (0.873–1.135), respectively.

Conclusion

Combined administration of rosuvastatin and ezetimibe was well tolerated. No clinically significant PK interactions between rosuvastatin and ezetimibe were observed when the 2 drugs were administered concomitantly.

Pharmacokinetic and pharmacodynamic interaction between ezetimibe and rosuvastatin in healthy male subjects

Background and objective

Rosuvastatin and ezetimibe are commonly applied in lipid-lowering pharmacotherapy. However, the pharmacokinetic (PK) interaction was not clear by the coadministration of rosuvastatin and ezetimibe. This study investigated the pharmacodynamic (PD) and PK interactions between rosuvastatin and ezetimibe through a crossover clinical trial.

Subjects and methods

A randomized, open-label, multiple-dose, two-treatment, two-period, two-sequence crossover study with two treatment parts was conducted in healthy male subjects. Study part A involved rosuvastatin, and study part B involved ezetimibe. A total of 25 subjects in both parts completed the PK and PD evaluations. Rosuvastatin (20 mg) or ezetimibe (10 mg) was administered once daily for 7 days as monotherapy or co-therapy. The plasma concentrations of rosuvastatin, total ezetimibe and free ezetimibe were measured for 72 h after day 7. Low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC) were investigated for the PD assessments on day 1 (pretreatment) and day 8.

Results

Rosuvastatin and ezetimibe presented multiple peaks. The 90% confidence intervals (CIs) of the geometric mean ratios for the peak plasma concentration at steady state (C_max,ss) and area under the plasma concentration-time curve during the dosing interval at steady state (AUC_τ,ss) of rosuvastatin and total ezetimibe were within the range 0.8-1.25. However, the coadministration increased the systemic exposure of free ezetimibe. In the PD assessments, rosuvastatin and ezetimibe monotherapy reduced the LDL-C and TC levels effectively. In addition, the lipid-lowering effects of the coadministration corresponded to an approximate summation of the effects of rosuvastatin and ezetimibe monotherapy. However, no significant changes in HDL-C were observed with rosuvastatin or ezetimibe treatment. No significant safety issue was noted.

Conclusion

The coadministration of rosuvastatin and ezetimibe revealed a bioequivalent PK interaction. Additional lipid-lowering effects, including decreased LDL-C and TC, were observed as expected in combination therapy without significant safety concern.

Thyroid Hormone Status in Sitosterolemia Is Modified by Ezetimibe

OBJECTIVES

To assess the association between biomarkers of thyroid status and 5α-stanols in patients with sitosterolemia treated with ezetimibe (EZE).

STUDY DESIGN

Eight patients with sitosterolemia (16-56 years of age) were studied during 14 weeks off EZE therapy and 14 weeks on EZE (10 mg/day). Serum thyroid biomarkers (free triiodothyronine [FT3], free thyroxine [FT4], FT3/FT4 ratio, thyroid-stimulating hormone), 5α-stanols (sitostanol and cholestanol), and cholestanol precursors (total cholesterol and its synthesis marker lathosterol, and 7α-hydroxy-4-cholesten-3-one cholestenol) were measured at baseline and during the 14 weeks off EZE and on EZE.

RESULTS

EZE increased FT3/FT4 (10% ± 4%; P = .02). EZE reduced plasma and red blood cells sitostanol (-38% ± 6% and -20% ± 4%; all P < .05) and cholestanol (-18% ± 6% and -13% ± 3%; all P < .05). The change in plasma cholestanol level on EZE inversely correlated with the change in FT3/FT4 (r = -0.86; P = .01). EZE lowered total cholesterol (P < .0001) and did not affect 7α-hydroxy-4-cholesten-3-one cholestanol. EZE increased (P < .0001) lathosterol initially, but the level was not sustained, resulting in similar levels at week 14 off EZE and on EZE.

CONCLUSION

In patients with STSL, 5α-stanols levels might be associated with thyroid function. EZE reduces circulating 5α-stanols while increasing FT3/FT4, implying increased conversion of T4 to T3, thus possibly improving thyroid hormone status.

TRIAL REGISTRATION

ClinicalTrials.govNCT01584206.

Ezetimibe

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16-Dehydropregnenolone lowers serum cholesterol by up-regulation of CYP7A1 in hyperlipidemic male hamsters

16-Dehydropregnenolone (DHP) has been developed and patented as a promising antihyperlipidemic agent by CSIR-Central Drug Research Institute (CSIR-CDRI), India. Although DHP is implicated in controlling cholesterol homeostasis, the mechanism underlying its pharmacological effect in hyperlipidemic disease models is poorly understood. In the present study, we postulated that DHP lowers serum lipids through regulating the key hepatic genes accountable for cholesterol metabolism. The hypothesis was tested on golden Syrian hamsters fed with high-fat diet (HFD) following oral administration of DHP at a dose of 72mg/kg body weight for a period of one week. The serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and total bile acids (TBA) in feces were measured. Real time comparative gene expression studies were performed for CYP7A1, LXRα and PPARα level in liver tissue of hamsters. The results revealed that the DHP profoundly decreased the levels of serum TC, TG, LDL-C and atherogenic index (AI), whilst elevated the HDL-C/TC ratio. Besides, DHP exhibited an anti-hyperlipidemic effect in the HFD induced hyperlipidemic hamsters by means of: (1) up-regulating the gene expression of CYP7A1 encoded cholesterol 7α-hydroxylase, that promotes the catabolism of cholesterol to bile acid; (2) inducing the gene expression of transcription factors LXRα and PPARα; (3) increasing the TBA excretion through feces. Collectively, the findings presented confer the hypolipidemic activity of DHP via up-regulation of hepatic CYP7A1 pathway that promotes cholesterol-to-bile acid conversion and bile acid excretion.

(S)-3-[(S)-5-(4-Fluorophenyl)-5-hydroxypentanoyl]-4-phenyloxazolidin-2-one 0.67-hydrate

The asymmetric unit of the title compound, 3C20H20FNO4·2H2O, consists of three (S)-3-[(S)-5-(4-fluorophenyl)-5-hydroxypentanoyl]-4-phenyloxazolidin-2-one molecules and two solvent water molecules. The carbonyl groups of the oxazolidin-2-one and hydroxypentanoyl units are orientedantito one another in each molecule. In the crystal, O—H...O, C—H...O and C—H...F hydrogen bonds link the molecules into a three-dimensional supramolecular architecture with the organic molecules linked by water molecules and stacked along theb-axis direction.

The Therapeutic Potential of Migrastatin-Core Analogs for the Treatment of Metastatic Cancer

Tumor metastasis is a complex process in which cells detach from the primary tumor and colonize a distant organ. Metastasis is also the main process responsible for cancer-related death. Despite the enormous efforts made to unravel the metastatic process, there is no effective therapy, and patients with metastatic tumors have poor prognosis. In this regard, there is an urgent need for new therapeutic tools for the treatment of this disease. Small molecules with the capacity to reduce cell migration could be used to treat metastasis. Migrastatin-core analogs are naturally inspired macrocycles that inhibit pathological cell migration and are able to reduce metastasis in animal models. Migrastatin analogs can be synthesized from a common advanced intermediate. Herein we present a review of the synthetic approaches that can be used to prepare this key intermediate, together with a review of the biological activity of migrastatin-core analogs and current hypotheses concerning their mechanism of action.

Inhibitory effect of ezetimibe can be prevented by an administration interval of 4 h between α-tocopherol and ezetimibe

Tocopherol is used not only as an ethical drug but also as a supplement. In 2008, it was reported that α-tocopherol is partly transported via an intestinal cholesterol transporter, Niemann-Pick C1-Like 1 (NPC1L1). Ezetimibe, a selective inhibitor of NPC1L1, is administered for a long time to inhibit cholesterol absorption and there is a possibility that the absorption of α-tocopherol is also inhibited by ezetimibe. This study investigated the influence of ezetimibe on the absorption of α-tocopherol with single administration and long-term administration. An approach to avoid its undesirable consequence was also examined. α-Tocopherol (10 mg/kg) and ezetimibe (0.1 mg/kg) were administered to rats, and the plasma concentration profiles of α-tocopherol and tissue concentrations were investigated. The plasma concentration of α-tocopherol was decreased by the combination use of ezetimibe in the case of concurrent single administration. On the other hand, inhibition of the absorption of α-tocopherol was prevented by an administration interval of 4 h. In a group of rats administered for 2 months with a 4 h interval, not only the plasma concentration but also the liver concentration was increased compared with those in a group with concurrent combination intake of α-tocopherol and ezetimibe. The absorption of α-tocopherol was inhibited by ezetimibe. The inhibitory effect of ezetimibe can be prevented by an administration interval of 4 h, although ezetimibe is a medicine of enterohepatic circulation. Attention should be paid to the use of ezetimibe and components of NPC1L1 substrates such as α-tocopherol. Copyright © 2016 John Wiley & Sons, Ltd.

Ezetimibe-sensitive cholesterol uptake by NPC1L1 protein does not require endocytosis

Human NPC1L1 protein mediates cholesterol absorption in the intestine and liver and is the target of the drug ezetimibe, which is used to treat hypercholesterolemia. Previous studies concluded that NPC1L1-GFP protein trafficking is regulated by cholesterol binding and that ezetimibe blocks NPC1L1-GFP function by inhibiting its endocytosis. We used cell surface biotinylation to monitor NPC1L1-GFP endocytosis and show that ezetimibe does not alter the rate of NPC1L1-GFP endocytosis in cultured rat hepatocytes grown under normal growth conditions. As expected, NPC1L1-GFP endocytosis depends in part on C-terminal, cytoplasmically oriented sequences, but endocytosis does not require cholesterol binding to NPC1L1's N-terminal domain. In addition, two small- molecule inhibitors of general (and NPC1L1-GFP) endocytosis failed to inhibit the ezetimibe-sensitive uptake of [(3)H]cholesterol from taurocholate micelles. These experiments demonstrate that cholesterol uptake by NPC1L1 does not require endocytosis; moreover, ezetimibe interferes with NPC1L1's cholesterol adsorption activity without blocking NPC1L1 internalization in RH7777 cells.

Ezetimibe Promotes Brush Border Membrane-to-Lumen Cholesterol Efflux in the Small Intestine

Ezetimibe inhibits Niemann-Pick C1-like 1 (NPC1L1), an apical membrane cholesterol transporter of enterocytes, thereby reduces intestinal cholesterol absorption. This treatment also increases extrahepatic reverse cholesterol transport via an undefined mechanism. To explore this, we employed a trans-intestinal cholesterol efflux (TICE) assay, which directly detects circulation-to-intestinal lumen 3H-cholesterol transit in a cannulated jejunal segment, and found an increase of TICE by 45%. To examine whether such increase in efflux occurs at the intestinal brush border membrane(BBM)-level, we performed luminal perfusion assays, similar to TICE but the jejunal wall was labelled with orally-given 3H-cholesterol, and determined elevated BBM-to-lumen cholesterol efflux by 3.5-fold with ezetimibe. Such increased efflux probably promotes circulation-to-lumen cholesterol transit eventually; thus increases TICE. Next, we wondered how inhibition of NPC1L1, an influx transporter, resulted in increased efflux. When we traced orally-given 3H-cholesterol in mice, we found that lumen-to-BBM 3H-cholesterol transit was rapid and less sensitive to ezetimibe treatment. Comparison of the efflux and fractional cholesterol absorption revealed an inverse correlation, indicating the efflux as an opposite-regulatory factor for cholesterol absorption efficiency and counteracting to the naturally-occurring rapid cholesterol influx to the BBM. These suggest that the ezetimibe-stimulated increased efflux is crucial in reducing cholesterol absorption. Ezetimibe-induced increase in cholesterol efflux was approximately 2.5-fold greater in mice having endogenous ATP-binding cassette G5/G8 heterodimer, the major sterol efflux transporter of enterocytes, than the knockout counterparts, suggesting that the heterodimer confers additional rapid BBM-to-lumen cholesterol efflux in response to NPC1L1 inhibition. The observed framework for intestinal cholesterol fluxes may provide ways to modulate the flux to dispose of endogenous cholesterol efficiently for therapeutic purposes.

The safety of ezetimibe and simvastatin combination for the treatment of hypercholesterolemia

INTRODUCTION

In the light of the most recent and stricter dyslipidemia treatment guidelines, the need for combination hypolipidemic therapy is increasing. Ezetimibe plus simvastatin is available as a fixed dose therapy offering an efficient hypolipidemic treatment choice. Based on the positive results of the IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) trial, the use of this drug combination is expected to increase in the next years.

AREAS COVERED

This review discusses the current evidence regarding the safety of ezetimibe/simvastatin combination. Current evidence regarding possible associated side effects (musculoskeletal, gastrointestinal, endocrine, hematological, renal, ophthalmologic, allergic, malignancy) and drug interactions of this combination is thoroughly discussed.

EXPERT OPINION

Ezetimibe and simvastatin treatment, either as a single pill or the combined use of the individual compounds, offers limited additional risk compared with simvastatin monotherapy and comprises a safe and efficient choice for dyslipidemia treatment in high-risk and diabetic patients.

The Role of Ezetimibe in the Treatment of Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Despite the success of treatment of CVD with statin therapy, a number of patients remain at high risk for CVD. Ezetimibe is a non-statin agent that inhibits intestinal cholesterol absorption, leading to reductions in low-density lipoprotein cholesterol (LDL-C). A number of clinical studies evaluating the use of ezetimibe therapy have resulted in discordant data regarding its safety and efficacy. In this review, we discuss the findings from these studies as well as potential indications for the use of ezetimibe for LDL-C lowering and cardiovascular event reduction.

Preventive role of green tea catechins from obesity and related disorders especially hypercholesterolemia and hyperglycemia

Background

During the last few years, scientific investigations have proposed diet based regimens to prevent several health ailments including obesity, hypercholesterolemia and diabetes. In this regard, a promising tool is the use of functional foods/nutraceuticals. Present research project was an attempt to explore nutraceutical worth of locally grown green tea variety (Qi-Men) against lifestyle related disorders.

Methods

Functional drinks (T₂ and T₃) were prepared by adding catechins and epigallocatechin gallate (EGCG) @ 550 mg/500 mL and compared with control (T₁). These functional drinks were tested in experimental rats modeling (Sprague Dawley). Based on diets, four studies were conducted i.e. trial-I (normal diet), trial-II (high cholesterol diet), trial-III (high sucrose diet), trial-IV (high cholesterol + high sucrose diet). Rats were monitored daily for their feed and drink intake while body weight was measured on weekly basis. After period of 56 days rats were sacrificed and evaluated their serum lipid (cholesterol, LDL and HDL), glucose and insulin levels.

Results

Results for feed consumption by rats revealed that highest feed intake was recorded in group provided control drink than other groups. However, non significant differences were noted among all groups for drink consumption. Functional drinks resulted in significant reduction in body weight with maximum lowering noted in trial-II and III i.e. 10.73 to 8.49% and 10.12 to 10.49%, respectively. Likewise, cholesterol and LDL were substantially reduced with 14.42% decrease observed in trial-IV and 30.43% in trial-II, respectively. Furthermore, serum glucose and insulin levels were also lowered significantly in the trial-III and IV while in trial-I and II differences were non-significant. In contrast to lipid profile, experimental drink containing EGCG reduced the trait better than catechins based functional drink.

Conclusions

The drinks supplemented with catechins and EGCG are effective against obesity, hypercholesterolemia and hyperglycemia.

Fomiroid A, a novel compound from the mushroom Fomitopsis nigra, inhibits NPC1L1-mediated cholesterol uptake via a mode of action distinct from that of ezetimibe

Hypercholesterolemia is one of the key risk factors for coronary heart disease, a major cause of death in developed countries. Suppression of NPC1L1-mediated dietary and biliary cholesterol absorption is predicted to be one of the most effective ways to reduce the risk of hypercholesterolemia. In a screen for natural products that inhibit ezetimibe glucuronide binding to NPC1L1, we found a novel compound, fomiroid A, in extracts of the mushroom Fomitopsis nigra. Fomiroid A is a lanosterone derivative with molecular formula C30H48O3. Fomiroid A inhibited ezetimibe glucuronide binding to NPC1L1, and dose-dependently prevented NPC1L1-mediated cholesterol uptake and formation of esterified cholesterol in NPC1L1-expressing Caco2 cells. Fomiroid A exhibited a pharmacological chaperone activity that corrected trafficking defects of the L1072T/L1168I mutant of NPC1L1. Because ezetimibe does not have such an activity, the binding site and mode of action of fomiroid A are likely to be distinct from those of ezetimibe.

Pharmacokinetic non-interaction analysis in a fixed-dose formulation in combination of atorvastatin and ezetimibe

Recent clinical research has shown that atorvastatin (ATO) in combination with cholesterol absorption inhibitor ezetimibe (EZE) significantly reduces LDL-C level in patients with hypercholesterolemia, showing a superior lipid-lowering efficacy compared to statin alone. With no information currently available on the interaction between the two drugs, a pharmacokinetic study was conducted to investigate the influence of EZE on ATO and conversely when the two drugs were coadministered. The purpose of this study was to investigate the presence of differences in the pharmacokinetic profiles of capsules containing ATO 80 mg, EZE 10 mg or the combination of both 80/10 mg administered to healthy Mexican volunteers. This was a randomized, three-period, six-sequences crossover study. 36 eligible subjects aged between 20 to 50 years were included. Blood samples were collected up to 96 h after dosing, and pharmacokinetic parameters were obtained by non-compartmental analysis. Adverse events were evaluated based on subject interviews and physical examinations. Area under the concentration-time curve (AUC) and maximum plasma drug concentration (C_max) were measured for each drug alone or together and tested for bioequivalence-based hypothesis. The estimation computed (90% confidence intervals) for AUC and C_max, were 96.04% (85.88–107.42%) and 97.04% (82.36–114.35%), respectively for ATO–EZE combination versus ATO alone, while 84.42% (77.19–92.32%) and 95.60% (82.43–110.88%), respectively, for ATO–EZE combination versus EZE alone were estimated. These results suggest that ATO and EZE have no relevant pharmacokinetic drug–drug interaction.

Novel strategy to boost oral anticoagulant activity of blood coagulation enzyme inhibitors based on biotransformation into hydrophilic conjugates

The blood coagulation cascade represents an attractive target for antithrombotic drug development, and recent studies have attempted to identify oral anticoagulants with inhibitory activity for enzymes in this cascade, with particular attention focused on thrombin and factor Xa (fXa) as typical targets. We previously described the discovery of the orally active fXa inhibitor darexaban (1) and reported a unique profile that compound 1 rapidly transformed into glucuronide YM-222714 (2) after oral administration. Here, we propose a novel strategy towards the discovery of an orally active anticoagulant that is based on the bioconversion of a non-amidine inhibitor into the corresponding conjugate to boost ex vivo anticoagulant activity via an increase in hydrophilicity. Computational molecular modeling was utilized to select a template scaffold and design a substitution point to install a potential functional group for conjugation. This strategy led to the identification of the phenol-derived fXa inhibitor ASP8102 (14), which demonstrated highly potent anticoagulant activity after biotransformation into the corresponding glucuronide (16) via oral dosing.

Fungal biotransformation of ezetimibe

Structural transformation of ezetimibe was performed by fungi Beauvaria bassiana and Cunninghamella blakesleeana. The metabolites were identified by different spectroscopic techniques as (3R,4S)-1-(4-fluorophenyl)-3-((E)-3-(4-fluorophenyl) allyl)-4-(4-hydroxyphenyl) azetidin-2-one (2), (3R, 4S)-1-(4-fluorophenyl)-3-(3-(4fluorophenyl)-3-oxopropyl)-4-(4-hydroxyphenyl) azetidin-2-one (3), (3R,4S) 1-(4-fluorophenyl)-3-(3-(4-fluorophenyl) propyl)-4-(4-hydroxyphenyl) azetidin-2-one (4) and (2R,5S)-N, 5-bis (4-fluorophenyl)-5-hydroxy-2-(4-hydroxybenzyl) pentanamide (5). This study displays two important features of these fungi, viz., their ability to metabolize halogenated compounds, and their capacity to metabolize drugs that are targets of the UDP-Glucuronyl Transferase System, a phenomenon not commonly observed.

Combination therapy with ezetimibe and simvastatin to achieve aggressive LDL reduction

A low-density lipoprotein (LDL) cholesterol goal of less than 100 mg/dl is recommended for patients at moderate to high risk of cardiovascular disease with an optional LDL goal of less than 70 mg/dl for patients at a very high risk of cardiovascular disease. Most patients will require reductions in LDL of more than 50% in order to achieve these more aggressive goals. Only a few agents will lower LDL by at least 50%. This review will focus on the efficacy and safety ezetimibe/simvastatin coadministered as a therapy with enhanced LDL-lowering efficacy, while minimizing the adverse effects of statins in a wide range of patients. Ezetimibe 10 mg/simvastatin 80 mg lowers LDL by approximately 60% and has been demonstrated to be superior to the highest doses of atorvastatin and rosuvastatin for lowering LDL and raising high-density lipoprotein.