Statins for all: the new premed?

Pharmacokinetics and Bioequivalence of Fixed-Dose Combination of Simvastatin and Ezetimibe Tablets: A Randomized, Crossover, Open-Label Study in Healthy Volunteers

The current study aimed to evaluate the bioequivalence of a new generic combination of simvastatin and ezetimibe with the reference formulation. An open-label, randomized, 3-period, 3-sequence, crossover study, including 60 healthy volunteers, was implemented. Participants received the test and reference formulation, each containing 20 mg of simvastatin and 10 mg of ezetimibe as a single-dose tablet, separated by a minimum of 2-week washout periods. Blood samples were collected for 20 time points from predose to 72 hours after the dose. The total ezetimibe assay was carried out using a validated liquid chromatography-tandem mass spectrometry, while unconjugated ezetimibe, simvastatin, and simvastatin β-hydroxy acid determination was done via a validated ultra-performance liquid chromatography-tandem mass spectrometry. Each assay was preceded by a liquid-liquid extraction step. The pharmacokinetic parameters were derived using noncompartmental analysis and then compared between the reference and test formulations via a multivariate analysis of variance. No statistical difference was found in under the concentration-time curve from time 0 to the last quantifiable concentration and maximum concentration of unconjugated ezetimibe, total ezetimibe, and simvastatin between the reference and test formulations. The 90% confidence intervals of unconjugated ezetimibe, total ezetimibe, and simvastatin natural log-transformed under the concentration-time curve from time 0 to the last quantifiable concentration, and maximum concentration were in the range of 80%-125% as per the bioequivalence acceptance criteria. Therefore, the test formulation was bioequivalent to the reference formulation.

Can Lipid-Lowering Drugs Reduce the Risk of Cholelithiasis? A Mendelian Randomization Study

Background and Aims

Cholelithiasis etiology intricately involves lipid metabolism. We sought to investigate the plausible causal link between genetically proxied lipid-lowering medications-specifically HMGCR inhibitors, PCSK9 inhibitors, and NPC1L1 inhibitors-and cholelithiasis risk.

Methods

Our study utilized two genetic instruments for exposure to lipid-lowering drugs. These instruments encompassed genetic variants linked to low-density lipoprotein (LDL) cholesterol within or in proximity to drug target genes, along with loci governing gene expression traits of these targets. Effect estimates were derived through Inverse-variance-weighted MR (IVW-MR) and summary-data-based MR (SMR) methods.

Results

Higher HMGCR-mediated LDL cholesterol levels (IVW-MR, OR = 2.15, 95% CI = 1.58-2.94; P = 0.000) and increased HMGCR expression (SMR, OR = 1.19, 95% CI = 1.04-1.37; P = 0.014) are linked to elevated cholelithiasis risk, suggesting potential benefits of HMGCR inhibition. In contrast, higher PCSK9-mediated LDL cholesterol levels (IVW-MR, OR = 0.72, 95% CI = 0.56-0.94; P = 0.015) and increased PCSK9 expression (SMR, OR = 0.90, 95% CI = 0.82-0.99; P = 0.035) both correlate with lower cholelithiasis risk, indicating that PCSK9 inhibition may elevate this risk. Nevertheless, no substantial link emerged between NPC1L1-mediated LDL cholesterol or NPC1L1 expression and cholelithiasis in both IVW-MR and SMR analyses.

Conclusion

This MR investigation affirms the causal link between the utilization of HMGCR inhibitors and a diminished risk of cholelithiasis. Additionally, it indicates a causal link between PCSK9 inhibitors use and increased cholelithiasis risk. However, no significant correlation was found between NPC1L1 inhibitors use and cholelithiasis risk.

Evaluation of statins as a new therapy to alleviate chronotropic dysfunction in cirrhotic rats

AIMS

Liver cirrhosis defines by regenerative nodules and fibrotic septa, causing a complication called cirrhotic cardiomyopathy (CCM) with chronotropic hypo-responsiveness. In addition to lowering cholesterol levels, statins yield antioxidant and anti-inflammatory effects. In liver diseases animal models, statins have been shown to decrease hepatic inflammation, fibrogenesis, and portal pressure (PP). Therefore, we evaluated the atorvastatin effect on the heart in cirrhotic rats.

MATERIALS AND METHODS

Bile duct ligation (BDL) or sham operation performed on male Wistar rats and grouped as cirrhotic; BDL/Saline, BDL/Ator-7d(days) (Atorvastatin 15 mg/kg/day), and BDL/Ator-14d groups, or control; Sham/Saline, Sham/Ator-7d, and Sham/Ator-14d groups. Corrected QT interval (QTc interval), chronotropic responses, serum brain natriuretic peptides (BNP), heart tumor necrosis factor-α (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2), and malondialdehyde (MDA) levels were studied along with atrial Ras homolog family member A (RhoA) and endothelial nitric oxide synthase (eNOS) gene expression.

KEY FINDINGS

The chronotropic responses decreased in BDL/Saline and increased in BDL/Ator-7d group. The QTc interval, BNP, TNF-α, and MDA levels increased in BDL/Saline and decreased in BDL/Ator-14d group. The Nrf2 level did not change in BDL/Saline and increased in BDL/Ator-14d group. The liver inflammation and fibrosis increased in BDL/Saline and did not affect BDL/Ator-7d and BDL/Ator-14d groups. The RhoA expression was down-regulated in BDL/Saline, BDL/Ator-7d, and BDL/Ator-14d groups. The eNOS expression did not change in BDL/Saline and down-regulated in BDL/Ator-14d group.

SIGNIFICANCE

Atorvastatin alleviates the chronotropic hypo-responsiveness and down-regulates the atrial RhoA and eNOS gene expression along with anti-inflammatory, antioxidant, and anti-stress effects in CCM.

Statin Therapy Is Associated With Decreased 90-Day Postoperative Mortality After Colon Cancer Surgery

BACKGROUND

There have been conflicting reports regarding a protective effect of statin therapy after colon cancer surgery.

OBJECTIVE

This study aimed to evaluate the association between statin therapy and the postoperative mortality following elective colon cancer surgery.

DESIGN

This population-based cohort study is a retrospective analysis of prospectively collected data from the Swedish Colorectal Cancer Register.

SETTINGS

Patient inclusion was achieved through a nationwide register.

PATIENTS

All adult patients undergoing elective surgery for colon cancer between January 2007 and September 2016 were included in the study. Patients who had received and collected a prescription for statins pre- and postoperatively were allocated to the statin-positive cohort.

MAIN OUTCOME MEASURES

The primary and secondary outcomes of interest were 90-day all-cause mortality and 90-day cause-specific mortality.

RESULTS

A total of 22,337 patients underwent elective surgery for colon cancer during the study period, of whom 6,494 (29%) were classified as statin users. Statin users displayed a significant survival benefit despite being older, having a higher comorbidity burden, and being less fit for surgery. Multivariate analysis illustrated significant reductions in the incidence risk for 90-day all-cause mortality (Incidence Rate Ratio = 0.12, p < 0.001) as well as 90-day cause-specific deaths due to sepsis, due to multiorgan failure, or resulting from a cardiovascular and respiratory origin.

LIMITATIONS

The limitations of this study include its observational retrospective design, restricting the ability to perform standardized follow-up of statin therapy. Confounding from other uncontrolled variables cannot be excluded.

CONCLUSIONS

Statin users had a significant postoperative benefit regarding short-term mortality following elective colon cancer surgery in the current study; however, further research is needed to ascertain whether this relationship is causal. See Video Abstract at http://links.lww.com/DCR/B738.

LA TERAPIA CON ESTATINAS SE ASOCIA CON UNA DISMINUCIN DE LA MORTALIDAD POSOPERATORIA A LOS DAS DESPUS DE LA CIRUGA DE CNCER DE COLON

ANTECEDENTES:Ha habido informes contradictorios con respecto al efecto protector de la terapia con estatinas después de la cirugía de cáncer de colon.OBJETIVO:Este estudio tuvo como objetivo evaluar la asociación entre la terapia con estatinas y la mortalidad postoperatoria después de la cirugía electiva por cáncer de colon.DISEÑO:Este estudio de cohorte poblacional es un análisis retrospectivo de datos recopilados prospectivamente del Registro Sueco de Cáncer Colorrectal.AJUSTES:La inclusión de pacientes se logró mediante la inclusión a través de un registro a nivel nacional.PACIENTES:Se incluyeron en el estudio todos los pacientes adultos sometidos a cirugía electiva por cáncer de colon en el período de enero de 2007 y septiembre de 2016. Los pacientes que habían recibido y recogido una receta de estatinas antes y después de la operación fueron asignados a la cohorte positiva de estatinas.PRINCIPALES MEDIDAS DE DESENLACES:Los desenlaces primarios y secundarios de interés fueron la mortalidad por cualquier causa a los 90 días y la mortalidad por causas específicas a los 90 días.RESULTADOS:Un total de 22.337 pacientes se sometieron a cirugía electiva por cáncer de colon durante el período de estudio, de los cuales 6.494 (29%) se clasificaron como usuarios de estatinas. Los usuarios de estatinas mostraron un beneficio significativo en la supervivencia a pesar de ser mayores, de tener una mayor carga de comorbilidad y de estar menos acondicionado para la cirugía. El análisis multivariado ilustró reducciones significativas en el riesgo de incidencia de mortalidad por cualquier causa a 90 días (índice de tasa de incidencia = 0,12, p < 0,001), así como muertes específicas ena 90 días debidas a sepsis, falla multiorgánica o dea enfermedades de origen cardiovascular y respiratorio.LIMITACIONES:Las limitaciones de este estudio incluyen su diseño observacional retrospectivo, que restringe la capacidad de realizar un seguimiento estandarizado de la terapia con estatinas. No se puede excluir confusión a partir de otras variables no controladas.CONCLUSIONES:Los usuarios de estatinas tuvieron un beneficio posoperatorio significativo con respecto a la mortalidad a corto plazo después de cirugía electiva por cáncer de colon en el estudio actual, sin embargo, se necesita más investigación para confirmar si eexiste una relación es causal. Consulte Video Resumen en http://links.lww.com/DCR/B738.

Fatty acids: facts vs. fiction

During the last 100 years official dietary guidelines have recommended an increased consumption of fats derived from seeds while decreasing the consumption of traditional fats, especially saturated fats. These recommendations are being challenged by recent studies. Furthermore, the increased use of refining processes in fat production had deleterious health effects. Today, the number of high-quality studies on fatty acids is large enough to make useful recommendations on clinical application and everyday practice. Saturated fats have many beneficial functions and palmitic acid appears to be problematic only when it is synthesized due to excess fructose consumption. Trans fatty acids were shown to be harmful when they are manmade but beneficial when of natural origin. Conjugated linoleic acid has many benefits but the isomer mix that is available in supplement form differs from its natural origin and may better be avoided. The ω3 fatty acid linolenic acid has rather limited use as an anti-inflammatory agent - a fact that is frequently overlooked. On the other hand, the targeted use of long chain ω3 fatty acids based on blood analysis has great potential to supplement or even be an alternative to various pharmacological therapies. At the same time ω6 fatty acids like linoleic acid and arachidonic acid have important physiological functions and should not be avoided but their consumption needs to be balanced with long chain ω3 fatty acids. The quality and quantity of these fats together with appropriate antioxidative protection are critical for their positive health effects.

Statin therapy and postoperative short-term mortality after rectal cancer surgery

AIM

This study aimed to assess the correlation between regular statin therapy and postoperative mortality following surgical resection for rectal cancer.

METHOD

This retrospective cohort study included all adult patients undergoing abdominal rectal cancer surgery in Sweden between January 2007 and September 2016. Data were gathered from the Swedish Colorectal Cancer Registry, a large population-based prospectively collected registry. Statin users were defined as patients with one or more collected prescriptions of a statin within 12 months before the date of surgery. The statin-positive and statin-negative cohorts were matched by propensity scores based on baseline demographics.

RESULTS

A total of 11 966 patients underwent surgical resection for rectal cancer, of whom 3019 (25%) were identified as statin users. After applying propensity score matching (1:1), 3017 pairs were available for comparison. In the matched groups, statin users demonstrated reduced 90-day all-cause mortality (0.7% vs. 5.5%, p < 0.001) and also showed significantly reduced cause-specific mortality due to cardiovascular and respiratory events, as well as sepsis and multiorgan failure. The significant postoperative survival benefit of statin users was seen despite a higher rate of cardiovascular comorbidity.

CONCLUSION

Preoperative statin therapy displays a strong association with reduced postoperative mortality following surgical resection for rectal cancer. The results from the current study warrant further investigation to determine whether a causal relationship exists.

Effect of rosuvastatin on the concentration of each fatty acid in the fraction of free fatty acids and total lipids in human plasma: The role of cholesterol homeostasis

Each fatty acid (FA) or class of FAs has a different behavior in the pathologies of atherosclerosis. The aim of this study was to investigate changes in the concentration of each fatty acid in the fraction of free fatty acids (FFAs) and total lipids in human plasma after short-term therapy with rosuvastatin as a cholesterol-lowering statin drug. Six hypercholesterolemic men on a habitual diet were studied in a randomized, double-blind, and crossover process. They received 20 mg rosuvastatin or placebo in random order, each for 4 weeks and after 2 weeks of washout period, they received another medication (placebo or rosuvastatin) for another period of 4 weeks. Rosuvastatin treatment significantly decreased the absolute concentrations of saturated and monounsaturated FAs in the total FAs as well as in FFAs. Long chain polyunsaturated fatty acids with 20 and 22 carbon atoms in the molecule had no significant change in the fraction of FFAs. Rosuvastatin is directly involved in cholesterol biosynthesis and indirectly through cholesterol homeostasis in the biosynthesis of other plasma lipids.

In conclusion, our findings show that rosuvastatin treatment leads to significant changes in the concentration of each fatty acid, except for long-chain polyunsaturated fatty acids in FFAs. Our observations indicate that cholesterol homeostasis through its regulatory mechanisms appears to be the main cause of changes in the concentration of each plasma fatty acid during rosuvastatin treatment. These changes can be a source of beneficial consequences, in addition to lowering low-density lipoprotein cholesterol in cardiovascular diseases.

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Rosuvastatin decreased the concentration of total fatty acids and free fatty acids.

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The change in the concentration of each fatty acid was analyzed.

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Changes in fatty acid concentrations are part of cholesterol homeostasis.

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These changes bring beneficial consequences in cardiovascular diseases.

A Brief Drug Class Review: Considerations for Statin Use, Toxicity, and Drug Interactions

For approximately 30 years, statins have been effectively used to control cholesterol, thereby reducing the morbidity and mortality associated with cardiovascular disease. Evidence-based recommendations regarding how these drugs are dosed and used have changed significantly through the years. There are seven statins approved for use in the United States, and although the mechanism of action pertaining to cholesterol reduction is the same for all statins, each has its own specific pharmacologic profile. One unique aspect of statin dosing is understanding the potential drug interactions associated with statin use; interactions can occur with all statins, but the mechanism and type of interaction can vary significantly among drugs. These interactions can result in significant elevations in statin blood concentrations, thereby increasing the risk of the adverse effects of statins, the most significant of which is muscle toxicity. Practitioners who care for patients receiving statins should understand the pharmacologic differences among these drugs, as well as the varied drug interaction potential that all statins possess.

Biosensors Incorporating Bimetallic Nanoparticles

This article presents a review of electrochemical bio-sensing for target analytes based on the use of electrocatalytic bimetallic nanoparticles (NPs), which can improve both the sensitivity and selectivity of biosensors. The review moves quickly from an introduction to the field of bio-sensing, to the importance of biosensors in today's society, the nature of the electrochemical methods employed and the attendant problems encountered. The role of electrocatalysts is introduced with reference to the three generations of biosensors. The contributions made by previous workers using bimetallic constructs, grouped by target analyte, are then examined in detail; following which, the synthesis and characterization of the catalytic particles is examined prior to a summary of the current state of endeavor. Finally, some perspectives for the future of bimetallic NPs in biosensors are given.

Coenzyme Q10 and statin-related myopathy

Statins inhibit the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, which is involved in the production of mevalonic acid in the cholesterol biosynthesis pathway. This pathway also results in the production of other bioactive molecules including coenzyme Q10 (also known as ubiquinone or ubidecarenone). Coenzyme Q10 is a naturally-occurring coenzyme with antioxidant effects that is involved in electron transport in mitochondria and is thought to play a role in energy transfer in skeletal muscle. Muscle-related problems are a frequently reported adverse effect of statins, and it has been hypothesised that a reduced endogenous coenzyme Q10 concentration is a cause of statin-induced myopathy. Coenzyme Q10 supplementation has therefore been proposed to reduce the adverse muscular effects sometimes seen with statins. Here, we consider whether coenzyme Q10 has a place in the management of statin-induced myopathy.

Atorvastatin reduces endotoxin-induced microvascular inflammation via NOSII

In a lipopolysaccharide (LPS)-induced rat model of sepsis (endotoxaemia), we previously demonstrated that pravastatin reduced microvascular inflammation via increased endothelial nitric oxide synthase III (NOSIII). This study aimed to determine whether atorvastatin, the most commonly used statin for lowering cholesterol, exerted beneficial pleiotropic effects via a similar mechanism. The mesenteric microcirculation of anaesthetised male Wistar rats (308 ± 63 g, n = 54) was prepared for fluorescent intravital microscopy. Over 4 h, animals received intravenous (i.v.) administration of either saline, LPS (150 μg kg(-1) h(-1)) or LPS + atorvastatin (200 μg kg(-1) s.c., 18 and 3 h before LPS), with/without the non-specific NOS inhibitor L-NG-Nitroarginine Methyl Ester (L-NAME) (10 μg kg(-1) h(-1)) or NOSII-specific inhibitor 1400 W (20 μg kg(-1) min(-1)). LPS decreased mean arterial blood pressure (MAP) (4 h, control 113 ± 20 mmHg; LPS 70 ± 23 mmHg), being reversed by atorvastatin (105 ± 3 mmHg) (p < 0.05). LPS also increased macromolecular leak measured after 100 mg kg(-1) of i.v FITC-BSA (arbitrary grey level adjacent to venules), which again was attenuated by atorvastatin (control 1.9 ± 4.0; LPS 12.0 ± 2.4; LPS + atorvastatin 4.5 ± 2.2) (p < 0.05). Furthermore, immunohistochemistry identified that atorvastatin decreased LPS-induced upregulation of endothelial cell NOSII expression, but NOSIII was unchanged in all groups. Atorvastatin improved MAP and reduced microvascular inflammation during endotoxaemia, associated with a reduction of pro-inflammatory NOSII. This differs from previous studies, whereby pravastatin increased expression of NOSIII. Thus preoperative statins have beneficial anti-inflammatory effects during endotoxaemia, but careful consideration must be given to the specific statin being used.

Lovastatin for adult patients with dengue: protocol for a randomised controlled trial

Background

Dengue is the most important vector-borne viral infection of man, with approximately 2 billion people living in areas at risk. Infection results in a range of manifestations from asymptomatic infection through to life-threatening shock and haemorrhage. One of the hallmarks of severe dengue is vascular endothelial disruption. There is currently no specific therapy and clinical management is limited to supportive care. Statins are a class of drug initially developed for lipid lowering. There has been considerable recent interest in their effects beyond lipid lowering. These include anti-inflammatory effects at the endothelium. In addition, it is possible that lovastatin may have an anti-viral effect against dengue. Observational data suggest that the use of statins may improve outcomes for such conditions as sepsis and pneumonia. This paper describes the protocol for a randomised controlled trial investigating a short course of lovastatin therapy in adult patients with dengue.

Methods/design

A randomised, double-blind, placebo-controlled trial will investigate the effects of lovastatin therapy in the treatment of dengue. The trial will be conducted in two phases with an escalation of dose between phases if an interim safety review is satisfactory. This is an exploratory study focusing on safety and there are no data on which to base a sample size calculation. A target sample size of 300 patients in the second phase, enrolled over two dengue seasons, was chosen based on clinical judgement and feasibility considerations. In a previous randomised trial in dengue, about 10% and 30% of patients experienced at least one serious adverse event or adverse event, respectively. With 300 patients, we will have 80% power to detect an increase of 12% (from 10% to 22%) or 16% (from 30% to 46%) in the frequency of adverse events. Furthermore, this sample size ensures some power to explore the efficacy of statins.

Discussion

The development of a dengue therapeutic that can attenuate disease would be an enormous advance in global health. The favourable effects of statins on the endothelium, their good safety profile and their low cost make lovastatin an attractive therapeutic candidate.

Trial registration

International Standard Randomised Controlled Trial Number ISRCTN03147572

LDL-induced impairment of human vascular smooth muscle cells repair function is reversed by HMG-CoA reductase inhibition

Growing human atherosclerotic plaques show a progressive loss of vascular smooth muscle cells (VSMC) becoming soft and vulnerable. Lipid loaded-VSMC show impaired vascular repair function and motility due to changes in cytoskeleton proteins involved in cell-migration. Clinical benefits of statins reducing coronary events have been related to repopulation of vulnerable plaques with VSMC. Here, we investigated whether HMG-CoA reductase inhibition with rosuvastatin can reverse the effects induced by atherogenic concentrations of LDL either in the native (nLDL) form or modified by aggregation (agLDL) on human VSMC motility. Using a model of wound repair, we showed that treatment of human coronary VSMC with rosuvastatin significantly prevented (and reversed) the inhibitory effect of nLDL and agLDL in the repair of the cell depleted areas. In addition, rosuvastatin significantly abolished the agLDL-induced dephosphorylation of myosin regulatory light chain as demonstrated by 2DE-electrophoresis and mass spectrometry. Besides, confocal microscopy showed that rosuvastatin enhances actin-cytoskeleton reorganization during lipid-loaded-VSMC attachment and spreading. The effects of rosuvastatin on actin-cytoskeleton dynamics and cell migration were dependent on ROCK-signalling. Furthermore, rosuvastatin caused a significant increase in RhoA-GTP in the cytosol of VSMC. Taken together, our study demonstrated that inhibition of HMG-CoA reductase restores the migratory capacity and repair function of VSMC that is impaired by native and aggregated LDL. This mechanism may contribute to the stabilization of lipid-rich atherosclerotic plaques afforded by statins.

[Effect of the administration of statins in non-cardiac critical disease]

Administration of statins has been shown to be effective in reducing cardiovascular mortality. Their benefit could expand towards other areas of intensive medicine, it being possible to decrease mortality of the critically ill patient. There are several studies, although without a high level of evidence, that have detected a possible benefit when they are administered as well as clinical deterioration when they are discontinued, compared to those patients who had previously taken them. Even though most of the patients who had previously taken statins did so as primary or secondary prevention, thus having greater comorbidity, overall, a decrease is detected in the mortality of these subgroups. This benefit could be generalized to all the critical conditions, although studies with a higher level of evidence are needed for their adequate comparison.

Use of statins in adhesive small bowel obstruction

BACKGROUND

Adhesive small bowel obstruction (ASBO) causes considerable morbidity and may require surgical intervention. The role of statins in adhesion prevention is of increasing interest, though no investigation of its impact on ASBO and operative rates has been conducted. This study investigates the impact of statin use on operative rates in ASBO.

METHODS

A retrospective review of all patients with ASBO within our institution from January 1997 to December 2007 was conducted. Demographic data, potential confounders, and treatment received (conservative/operative) were recorded. Statistical significance was determined using the two-tailed Fisher's exact test for categorical data and the Mann-Whitney U test for continuous data. Univariate and logistic regression were conducted to control for potential known confounders.

RESULTS

There were 419 cases of ASBO with 253 (60.4%) females. The median age of diagnosis was 62 (15-93) years and the median ASA score was 2 (1-4). Forty-nine (11.7%) patients required operative management, the median day-stay was three (1-154) d and 151 (36%) patients were taking statins. On univariate analysis, statin use was associated with decreased operative rates (P = 0.02). The relative risk was 0.46 with an absolute risk reduction of 7.9% (95% CI: 2.1%-13.7%). The number needed to treat was 13 (NNT = 13; 95% CI: 7.3-46.8). Statin use was associated with decreased operative rates using a logistic regression model (P = 0.04).

CONCLUSION

Statin use is independently associated with decreased operative rates in ASBO.

Effects of AMP-activated protein kinase in cerebral ischemia

AMP-activated protein kinase (AMPK) is a serine threonine kinase that is highly conserved through evolution. AMPK is found in most mammalian tissues including the brain. As a key metabolic and stress sensor/effector, AMPK is activated under conditions of nutrient deprivation, vigorous exercise, or heat shock. However, it is becoming increasingly recognized that changes in AMPK activation not only signal unmet metabolic needs, but also are involved in sensing and responding to 'cell stress', including ischemia. The downstream effect of AMPK activation is dependent on many factors, including the severity of the stressor as well as the tissue examined. This review discusses recent in vitro and in vivo studies performed in the brain/neuronal cells and vasculature that have contributed to our understanding of AMPK in stroke. Recent data on the potential role of AMPK in angiogenesis and neurogenesis and the interaction of AMPK with 3-hydroxy-3-methy-glutaryl-CoA reductase inhibitors (statins) agents are highlighted. The interaction between AMPK and nitric oxide signaling is also discussed.

Polysaccharide from fuzi (FPS) prevents hypercholesterolemia in rats

BACKGROUND AND AIM

Polysaccharide from fuzi (FPS), a Chinese herbal medicine extract, has been demonstrated to exert lipid lowering affects. In this study we examined potential mechanisms underlying this affect, specifically alterations in expression of the LDL-receptor (LDL-R), 3-hydroxy-3-methyl glutaryl (HMG)-CoA reductase and cytochrome P450 7alpha-1 (CYP7alpha-1), using a rat model of hypercholesterolemia.

METHODS AND RESULTS

Male rats were fed either a normal or high cholesterol (HC) diet for two-weeks. Half of the rats on the HC diet were orally gavaged with FPS (224 mg/kg, 448 mg/kg or 896 mg/kg diet) daily. Serum lipid levels were quantified at end of the study period as were liver levels of LDL-R protein and mRNA expression of CYP7alpha-1 and HMG-CoA. Serum cholesterol and LDL-C concentrations were significantly elevated from control in HC rats, but not in those treated with FPS (P < 0.05). LDL-R expression was significantly decreased in the HC group compared to control (P < 0.05), but significantly increased in the FPS group (P < 0.05). HMG-CoA mRNA levels were significantly increased in the HC group compared both other groups (P < 0.05), while CYP7alpha-1 expression was significantly higher in the FPS group compared to both other groups (P < 0.05).

CONCLUSION

These findings suggest that the cholesterol lowering effect of FPS in hypercholesteremic rats is caused at least in part by increased hepatic LDL-R and CYP7alpha-1 expression and decreased HMG-CoA expression. Further study is needed to determine precisely where and how FPS exerts these effects. FPS offers potential as a therapeutic agent for the treatment of hypercholesterolemia.