Vascular and metabolic effects of treatment of combined hyperlipidemia: focus on statins and fibrates

Effects of Pemafibrate on Cardio-Ankle Vascular Index (CAVI) in Patients with Type 2 Diabetes or Ischemic Heart Disease: A 24-Week Observational Study

Purpose

Pemafibrate is a novel selective peroxisome proliferator-activated receptor alpha modulator (SPPARMα) that improves lipid profile, but its effects on cardiovascular events remain unproven. This study examined changes in the cardio-ankle vascular index (CAVI), a marker of arterial stiffness, in high-risk patients with type 2 diabetes mellitus (T2DM) or ischemic heart disease (IHD) treated with pemafibrate.

Patients and Methods

In this single-center, prospective, observational study, 95 patients with T2DM and/or IHD, who had hypertriglyceridemia (≥150 mg/dL) and started pemafibrate (0.2 mg/day) were analyzed. CAVI was measured at baseline and after 24 weeks of treatment as an indicator of arterial stiffness, along with comprehensive assessment of lipid parameters including triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-HDL-C, and apolipoproteins.

Results

No significant change in CAVI was observed after 24 weeks of treatment (median [interquartile range (IQR)]; baseline vs 24 weeks: CAVI 9.4 [8.8-10.6] vs 9.6 [8.9-10.8], p=0.715). However, pemafibrate significantly reduced triglycerides (233 mg/dL [171-329] to 143 mg/dL [111-187], p<0.001), apolipoprotein C-II (8.1 mg/dL [6.1-10.2] to 6.3 mg/dL [5.3-8.3], p<0.001), apolipoprotein C-III (15.3 mg/dL [12.2-18.3] to 11.6 mg/dL [9.3-14.2], p<0.001) and liver enzymes; and increased HDL-C (45 mg/dL [39-52] to 50 mg/dL [40-60], p<0.001), LDL-C (92 mg/dL [70-111] to 103 mg/dL [79-128], p<0.001), apolipoprotein A-I and apolipoprotein A-II (both p<0.05). Calculated small dense low-density lipoprotein cholesterol also decreased significantly (40 mg/dL [31-49] to 36 mg/dL [28-45], p=0.002).

Conclusion

While pemafibrate improves lipid profile and liver enzymes, its short-term impact on vascular stiffness, as measured by CAVI, appears limited. Extended follow-up studies are needed to clarify its cardiovascular benefits in high-risk patients.

Fenofibrate Improves Cognitive Impairment Induced by High-Fat High-Fructose Diet: A Possible Role of Irisin and Heat Shock Proteins

A high-fat, high-fructose diet (HFFD) impairs cognitive functions and increases susceptibility to neurodegenerative disorders. Irisin and heat shock protein 70 (HSP70) are well known for their role in neuroprotection. The possible neuroprotective effects of fenofibrate on HFFD-induced cognitive dysfunction and the involvement of irisin and HSP70 in these effects were investigated in this study. Rats were divided into normal control, HFFD, dimethylsulfoxide+HFFD, and fenofibrate+HFFD groups. At the end of the experiment, fenofibrate treatment restored hippocampus histological characteristics to almost normal and improved HFFD-induced cognitive deficit. It reduced body weight gain and had hypolipidemic effects by significantly lowering total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels while increasing high-density lipoprotein cholesterol levels. It has antioxidant and anti-inflammatory effects as it significantly reduced the hippocampal malondialdehyde, interleukin-6, and tumor necrosis factor-alpha levels, while significantly increasing the reduced glutathione level. It prevented HFFD-induced hypoxia by significantly lowering hippocampal vascular endothelial growth factor and hypoxia-inducible factor-1 alpha levels. It significantly activated the hippocampal peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α)/irisin/brain-derived neurotrophic factor pathway. It significantly increased hippocampal HSP70 while decreasing the HSP90 levels. It enhanced synaptic plasticity by significantly upregulating the hippocampal relative GluR1 gene expression. Furthermore, hippocampal irisin levels in the HFFD group were found to be positively correlated with cognitive function, hippocampal HSP70, and relative GluR1 gene expression levels, while negatively correlated with hippocampal HSP90 and HIF1α levels. Therefore, fenofibrate may be used as a potential medication to treat HFFD-induced neurodegenerative disorders.

Effect of Omega-3 Fatty Acid Alone and in Combination with Proprietary Chromium Complex on Endothelial Function in Subjects with Metabolic Syndrome: A Randomized, Double-Blind, Parallel-Group Clinical Study

Metabolic syndrome (MetS) represents a cluster of metabolic abnormalities that include hypertension, central obesity, insulin resistance, and dyslipidemia and is strongly associated with an increased risk of diabetes, cardiovascular diseases (CVD), and all-cause mortality. Early diagnosis is important to employ lifestyle and risk factor modification. Existing therapies are limited. Studies report positive effect of omega-3 fatty acids (ω-3FA) on symptoms of metabolic syndrome. The present study was undertaken to evaluate the effect of ω-3FA alone and in combination with proprietary chromium complex (PCC) on endothelial function in subjects with metabolic syndrome. In this randomized, double-blind, parallel-group study, subjects were enrolled into the study after ethics committee (EC) approval and informed consent. Eligible subjects were randomized to receive ω-3FA concentrate 2000 mg (Group A-18 subjects), ω-3FA concentrate 2000 mg + PCC200 mcg (Group B-19 subjects), and ω-3FA concentrate 2000 mg + PCC400 mcg (Group C-21 subjects) daily for 12 weeks. Endothelial dysfunction as measured by reflection index (RI), biomarkers of oxidative stress (NO, MDA, and glutathione), and inflammation (hsCRP, endothelin-1, ICAM-1, and VCAM-1) were evaluated at baseline, 4, and 12 weeks. Lipid-profile and platelet-aggregation tests were performed at baseline and 12 weeks. Adverse drug reactions were recorded. Compliance was assessed by pill count method. GraphPad Prism8 was used for statistical analysis. Significant changes were seen from 4 weeks onwards in all the parameters evaluated. Significant improvement in RI% (mean ± SD = -2.56 ± 0.77 to -3.27 ± 0.67-group A, -2.33 ± 0.76 to 4.72 ± 0.79-group B; -2.39 ± 1.13 to 6.46 ± 1.00-group C) was seen at 12 weeks. Significant improvement in biomarkers of oxidative stress and inflammation was seen with all the treatment groups. Similarly, significant improvement in lipid profile was seen in group B and group C, while group A showed change in HDL, VLDL, and TG. Group C demonstrated the best response in the parameters evaluated. Three patients in group C reported gastrointestinal adverse events, which resolved spontaneously; none stopped the therapy. So, the addition of PCC to ω-3FA may prove to have beneficial effect in reducing cardiovascular morbidity in MetS patients.

Metabolic syndrome and its components in postmenopausal women living in southern Italy, Apulia region

OBJECTIVES

The goal of our study was to determine the prevalence of metabolic syndrome (MetS) and all its components, in a population of postmenopausal women aged over 45 years, consecutively accessed to our Heart Station, during 2014, for their first cardiac examination,furthermore to estimate their cardiovascular risk and the achievement of target blood values of main risk factors, according to current Guidelines.

METHODS

We screened 1257 postmenopausal women. MetS was assessed according to the National-Cholesterol-Education-Program-Adult-Treatment-Panel III definition. Cardiovascular risk was calculated by the Systematic Coronary Risk Evaluation (<65 years).

RESULTS

MetS was assessed on 834 women (66.4%). Prevalence of each component was: hypertension on 767 women (91.9%), central obesity 758 women (90.9%), low high-density lipoproteins cholesterol (HDLc) increased levels 612 women (73.3%), high triglyceride levels 428 women (51.3%), glucose levels higher than 110mg/dl or diabetes 404 women (48.5%). Cardiovascular risk was moderate until 65 years, but it increases after. Metabolic control in postmenopausal women was poor for glucose, only 82 women (9.8%) presented glucose levels lower than 110mg/dl, it was better for systolic blood pressure, that was normal in 564 women (67.6%) and worse for lipid levels.

CONCLUSION

The prevalence of metabolic syndrome in our population of postmenopausal women is high. Hypertension and central obesity are the more common components. The cardiovascular risk is moderate-high, the achievement of target values for glycemic and lipid levels is unsatisfactory, while systolic blood pressure is enough well controlled but however it is mandatory to improve this goal. An early MetS diagnosis and an early educational intervention are useful to decrease cardiovascular risk of postmenopausal women affected by metabolic syndrome.

Vascular and metabolic effects of omega-3 fatty acids combined with fenofibrate in patients with hypertriglyceridemia

BACKGROUND

Effects of omega-3 fatty acids (n-3 FA) combined with fenofibrate are not yet investigated, compared with fenofibrate.

METHODS

This was a randomized, single-blind, placebo-controlled, parallel study. Age, sex, and body mass index were matched among groups. All patients were recommended to maintain a low fat diet. Fifty patients with hypertriglyceridemia in each group were given placebo, n-3 FA 2g+fenofibrate 160mg (combination), or fenofibrate 160mg, respectively daily for 2months.

RESULTS

Placebo, combination, and fenofibrate significantly decreased triglycerides by 7%, 41% and 30%, respectively and triglycerides/HDL cholesterol ratio by 11%, 45% and 32%, respectively relative to baseline measurements (all P<0.05 by paired t-test). When compared with placebo and fenofibrate, these with combination were significant (P<0.001 by ANOVA). When compared with placebo, both combination and fenofibrate significantly decreased apolipoprotein B and non-HDL cholesterol and improved flow-mediated dilation and reduced CRP and fibrinogen (all P<0.05 by ANOVA), however, there were no significant differences between combination and fenofibrate. When compared with placebo, both combination and fenofibrate significantly reduced insulin and glucose (both P<0.05 by ANOVA), and improved insulin sensitivity (P=0.005 by ANOVA). However, there were no significant differences between combination and fenofibrate.

CONCLUSIONS

When compared with fenofibrate, combination significantly decreased triglycerides and triglycerides/HDL cholesterol ratio. Otherwise, combination and fenofibrate significantly reduced apolipoprotein B and non-HDL cholesterol and improved flow-mediated dilation and reduced CRP and fibrinogen to a similar extent. Also, combination and fenofibrate significantly improved insulin sensitivity to a similar extent by reducing insulin and glucose in patients with hypertriglyceridemia.

An experimental study on amelioration of dyslipidemia-induced atherosclesis by Clematichinenoside through regulating Peroxisome proliferator-activated receptor-α mediated apolipoprotein A-I, A-II and C-III

Prevention or amelioration the prevalence of atherosclerosis has been an effective strategy in the management of cardiovascular diseases. The aim of the study was to scrutinize the effect of Clematichinenoside (AR) on dyslipidemia-induced atherosclerosis and explore its capability on expression of Peroxisome proliferator-activated receptor-α (PPAR-alpha), apolipoprotein A-I (APOA1) and A-II (APOA2), and suppression of apolipoprotein C-III (APOC3) genes and proteins. In the present study, we investigated atherosclerosis effect of AR using a combination of high-fat diet and balloon injury model in rabbits. The levels of biochemical indicators were evaluated in plasma, liver and HepG2 cells using immunoassay technology. In order to expose the underlying mechanism, we evaluated the regulation of PPAR-alpha, APOA1, APOA2 and APOC3 expressions by AR, and we further evaluated the interactions between them after transfection with shRNA (shPPAR-alpha) and, the action of PPAR-alpha in HepG2 cells. We could find that AR markedly promoted the PPAR-alpha transfer from cytoplasm to nucleus which resulted in the alteration of APOA1, APOA2 and APOC3 expressions in HepG2 cells. Moreover, AR significantly reduced total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C) levels, and elevated high-density lipoprotein cholesterol (HDL-C) level, which play an important role in dyslipidemia-induced atherosclerosis. In conclusion, AR ameliorated atherosclerosis via the regulation of hepatic lipid metabolism, and AR also contributed to the activation of PPAR-alpha, APOA1, APOA2 and APOC3. Therefore, AR could be a potential therapeutic agent in the treatment of atherosclerosis.

Differential metabolic actions of specific statins: clinical and therapeutic considerations

SIGNIFICANCE

Statins, the most widely prescribed drugs in clinical practice, mainly act by reducing the plasma level of low-density lipoprotein (LDL)-cholesterol. A shift in redox homeostasis to an imbalance between reactive oxygen species generation and endogenous antioxidant mechanisms results in oxidative stress that has been implicated in the pathogenesis of various diseases, including those of the cardiovascular system. Beyond their efficacy in lowering LDL cholesterol, statins modulate redox systems that are implicated in the development of atherosclerosis, cardiovascular morbidity, and mortality.

RECENT ADVANCES

Differences in specific statins or their dosages result in differential metabolic actions arising from off-target or unknown mechanisms of action that can have important implications for overall patient morbidity and mortality.

CRITICAL ISSUES

A recent meta-analysis and a combined analysis have suggested that high doses of statins increase the risk of developing type 2 diabetes mellitus, but reduce the risk of cardiovascular events. Thus, it is important to consider the cardiovascular and metabolic context and natural history of diseases when choosing a specific statin therapy for optimal individual patient health over the long term.

FUTURE DIRECTIONS

More information is needed regarding the metabolism of statins, and the off-target or unknown actions of statins in affecting insulin resistance and metabolic homeostasis. The differential metabolic effects of specific statins should be considered in formulating optimal therapeutic strategies to reduce not just cardiovascular-related but also overall patient morbidity and mortality.

The prevalence of metabolic syndrome and its predominant components among pre-and postmenopausal Ghanaian women

BACKGROUND

Metabolic Syndrome (MetS) is a clump of risk factors for development of type 2 diabetes mellitus and cardiovascular diseases. Menopause and age are thought to predispose women to the development of metabolic syndrome. This study aimed to estimate the prevalence of MetS and identify its predominant components among pre-and postmenopausal women in the Kumasi Metropolis, Ghana.Two hundred and fifty (250) Ghanaian women were randomly selected for the study. They were evaluated for the prevalence of metabolic syndrome using the World Health Organization (WHO), National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), International Diabetes Federation (IDF) and Harmonization (H_MS) criteria.

RESULTS

Out of the total subjects, 143 (57.2%) were premenopausal and 107 (42.8%) menopausal. The study population was between the ages of 20-78 years. The overall percentage prevalence of MetS were 14.4%, 25.6%, 29.2% and 30.4% according to the WHO, NCEP-ATP III, IDF and H_MS criteria, respectively. The prevalence was found to increase with age, irrespective of criterion used. Generally, MetS was significantly higher among postmenopausal women (p < 0.05 by all criteria) compared to their premenopausal cohort, but with marked inter-criteria variations. Abdominal obesity, blood pressure, fasting blood glucose, triglyceride, very low density lipoprotein cholesterol, and triglyceride-high density lipoprotein cholesterol ratio were significantly (p < 0.05) different among the two groups of women.Central obesity, higher blood pressure and raised fasting blood glucose were the predominant components that contributed to the syndrome in Ghanaian women.

CONCLUSION

The higher prevalence of the metabolic syndrome in postmenopausal women is an indication that they are at risk of developing cardiovascular disease and type 2 diabetes. Therefore women in that group should be monitored for the two conditions and also be advised to adopt healthy lifestyles to minimize the incidence of these conditions.

Role of lipotoxicity in endothelial dysfunction

Vascular endothelial dysfunction is determined by both genetic and environmental factors that cause decreased bioavailability of the vasodilator nitric oxide. This is a hallmark of atherosclerosis, hypertension, and coronary heart disease, which are major complications of metabolic disorders, including diabetes and obesity. Several therapeutic interventions, including changes in lifestyle as well as pharmacologic treatments, are useful for improving endothelial dysfunction in the face of lipotoxicity. This review discusses the current understanding of molecular and physiologic mechanisms underlying lipotoxicity-mediated endothelial dysfunction as well as relevant therapeutic approaches to ameliorate dyslipidemia and consequent endothelial dysfunction that have the potential to improve cardiovascular and metabolic outcomes.

The case for intraocular delivery of PPAR agonists in the treatment of diabetic retinopathy

Background

Systemic therapeutics targeting the peroxisome proliferator-activated receptors have been found to be beneficial in the treatment of diabetic retinopathy. In this paper, we provide a rationale for the use of these therapeutics as intraocular agents. In addition, we introduce the peroxisome proliferator-activated receptors and describe their functions in response to the drugs.

Discussion

Based on the evidence of large-scale clinical studies investigating the systemic administration of fenofibrate, this ligand for peroxisome proliferator-activated receptor-α is potentially a good candidate for intraocular delivery. Here, we describe the mechanisms by which it might be acting to improve diabetic retinopathy, its relative safety and we speculate on how it could be developed for intraocular delivery.

Summary

In this paper, we provide a rationale for the further investigation of peroxisome proliferator-activated receptor-α agonists as intraocular agents for the treatment of diabetic retinopathy.

Fenofibrate increases high-density lipoprotein and sphingosine 1 phosphate concentrations limiting abdominal aortic aneurysm progression in a mouse model

There are currently no acceptable treatments to limit progression of abdominal aortic aneurysm (AAA). Increased serum concentrations of high-density lipoprotein (HDL) are associated with reduced risk of developing an AAA. The present study aimed to assess the effects of fenofibrate on aortic dilatation in a mouse model of AAA. Male low-density lipoprotein receptor-deficient (Ldlr(-/-)) mice were maintained on a high-fat diet for 3 weeks followed by 6 weeks of oral administration of vehicle or fenofibrate. From 14 to 18 weeks of age, all mice were infused with angiotensin II (AngII). At 18 weeks of age, blood and aortas were collected for assessment of serum lipoproteins, aortic pathology, aortic Akt1 and endothelial nitric oxide synthase (eNOS) activities, immune cell infiltration, eNOS and inducible NOS (iNOS) expression, sphingosine 1 phosphate (S1P) receptor status, and apoptosis. Mice receiving fenofibrate had reduced suprarenal aortic diameter, reduced aortic arch Sudan IV staining, higher serum HDL levels, increased serum S1P concentrations, and increased aortic Akt1 and eNOS activities compared with control mice. Macrophages, T lymphocytes, and apoptotic cells were less evident and eNOS, iNOS, and S1P receptors 1 and 3 were up-regulated in aortas from mice receiving fenofibrate. The present findings suggest that fenofibrate antagonizes AngII-induced AAA and atherosclerosis by up-regulating serum HDL and S1P levels, with associated activation of NO-producing enzymes and reduction of aortic inflammation.

The pharmacological effects of novel 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamide derivatives on plasma lipid profile of Triton-WR-1339-induced Wistar rats

A novel series of 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamides (3c-3g) were synthesized. The present study was undertaken to investigate the possible antihyperlipidemic effect of these novel compounds on hyperlipidemic rats. Hyperlipidemia was induced by a single intraperitoneal injection of Triton WR-1339 (300 mg/kg). The tested animals were divided into normal control (NCG), hyperlipidemic control (HCG), compounds 3c-, 3d-, 3e-, 3f-, 3g- and bezafibrate (BF)-treated groups. At a dose of 15 mg/kg, compounds 3c-3g and BF (100 mg/kg) significantly (p < 0.0001) reduced elevated plasma triglycerides levels after 12 and 24 h compared to the hyperlipidemic control group. However, only compounds 3e and 3g obviously showed a significant (p < 0.0001) reduction in plasma total cholesterol levels after 12 and 24 h. Moreover, high-density lipoprotein cholesterol levels were significantly increased in all treated groups. The current study demonstrates that 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamides (3c-3g) have a definite antihyperlipidemic potential and these beneficial activities may contribute to their cardioprotective and antiatherosclerotic role.

Fenofibrate reduces mortality and precludes neurological deficits in survivors in murine model of Japanese encephalitis viral infection

BACKGROUND

Japanese encephalitis (JE), the most common form of viral encephalitis occurs periodically in endemic areas leading to high mortality and neurological deficits in survivors. It is caused by a flavivirus, Japanese encephalitis virus (JEV), which is transmitted to humans through mosquitoes. No effective cure exists for reducing mortality and morbidity caused by JEV infection, which is primarily due to excessive inflammatory response. Fenofibrate, a peroxisome proliferator-activated receptor-α (PPARα) agonist is known to resolve inflammation by repressing nuclear factor-κB (NF-κB) and enhancing transcription of anti-oxidant and anti-inflammatory genes. In addition, fenofibrate also up-regulates a class of proteins, cytochrome P4504Fs (Cyp4fs), which are involved in detoxification of the potent pro-inflammatory eicosanoid, leukotriene B(4) (LTB(4)) to 20-hydroxy LTB(4).

METHODOLOGY/PRINCIPAL FINDINGS

The neuroprotective effect of fenofibrate was examined using in vitro (BV-2 microglial cell line) and in vivo (BALB/c mice) models of JEV infection. Mice were treated with fenofibrate for 2 or 4 days prior to JEV exposure. Pretreatment with fenofibrate for 4 but not 2 days reduced mortality by 80% and brain LTB(4) levels decreased concomitantly with the induction of Cyp4f15 and 4f18, which catalyze detoxification of LTB(4) through hydroxylation. Expression of cytokines and chemokine decreased significantly as did microglial activation and replication of the JEV virus.

CONCLUSIONS/SIGNIFICANCE

Fenofibrate confers neuroprotection against Japanese encephalitis, in vivo, in mouse model of JEV infection. Thus, fenofibrate, a PPARα agonist that is commonly used as a hypolipidemic drug could potentially be used for prophylaxis during JE epidemics to reduce mortality and morbidity.

Significant differential effects of omega-3 fatty acids and fenofibrate in patients with hypertriglyceridemia

BACKGROUND

Omega-3 fatty acids and fenofibrate are both used to treat patients with hypertriglyceridemia. However, a head-to-head comparison of the lipoprotein and metabolic effects of these two medicines has not been published.

METHODS

This was a randomized, single-blind, placebo-controlled, parallel study. Age, sex, and body mass index were matched among groups. All patients were recommended to maintain a low fat diet. Fifty patients in each group were given placebo, omega-3 fatty acids 2 g (most commonly used dosage in Korean patients), or fenofibrate 160 mg, respectively daily for 2 months.

RESULTS

Omega-3 fatty acids therapy decreased triglycerides by 21% and triglycerides/HDL cholesterol and improved flow-mediated dilation (P<0.01), however, did not significantly change insulin, plasma adiponectin levels, and insulin sensitivity (determined by QUICKI) relative to baseline measurements. Fenofibrate therapy decreased total cholesterol, triglycerides by 29%, and triglycerides/HDL-cholesterol (all P<0.01) and improved flow-mediated dilation when compared with baseline. When compared with placebo and omega-3 fatty acids, fenofibrate therapy decreased non-HDL cholesterol (P<0.001) and triglycerides/HDL cholesterol (P=0.016) while increasing HDL cholesterol (P<0.001) and apolipoprotein AI (P=0.001). Of note, when compared with omega-3 fatty acids, fenofibrate therapy decreased fasting insulin (P=0.023) and increased plasma adiponectin (P=0.002) and insulin sensitivity (P=0.015).

CONCLUSIONS

Omega-3 fatty acids and fenofibrate therapy promoted similar changes in triglycerides and endothelium-dependent dilation. However, fenofibrate therapy had substantially better effects on lipoprotein and metabolic profiles in patients with hypertriglyceridemia.

Antihyperlipidemic effects of Salvia officinalis L. leaf extract in patients with hyperlipidemia: a randomized double-blind placebo-controlled clinical trial

Hyperlipidemia is a common metabolic disorder contributing to morbidities and mortalities due to cardiovascular and cerebrovascular diseases. Conventional antihyperlipidemic drugs have limited efficacies and important side effects, so that alternative lipid lowering agents are needed. Salvia officinalis L. (sage) leaves have PPAR γ agonistic, pancreatic lipase and lipid absorption inhibitory, antioxidant, lipid peroxidation inhibitory and antiinflammatory effects. Thus, in this randomized double-blind placebo-controlled clinical trial with 67 hyperlipidemic (hypercholesterolemic and/or hypertriglyceridemic) patients aged 56.4 ± 30.3 years (mean ± SD), the effects of taking sage leaf extract (one 500 mg capsule every 8 h for 2 months) on fasting blood levels of lipids, creatinine and liver enzymes including SGOT and SGPT were evaluated in 34 patients and compared with the placebo group (n = 33). The extract lowered the blood levels of total cholesterol (p < 0.001), triglyceride (p = 0.001), LDL (p = 0.004) and VLDL (p = 0.001), but increased the blood HDL levels (p < 0.001) without any significant effects on the blood levels of SGOT, SGPT and creatinine (p > 0.05) compared with the placebo group at the endpoint. No adverse effects were reported. The results suggest that sage may be effective and safe in the treatment of hyperlipidemia.

Inhibition of human sterol Δ7-reductase and other postlanosterol enzymes by LK-980, a novel inhibitor of cholesterol synthesis

Novel potential inhibitors of the postsqualene portion of cholesterol synthesis were screened in HepG2 cells. 2-(4-Phenethylpiperazin-1-yl)-1-(pyridine-3-yl)ethanol (LK-980) was identified as a prospective compound and was characterized further in cultures of human primary hepatocytes from seven donors. In vitro kinetic measurements show that the half-life of LK-980 is at least 4.3 h. LK-980 does not induce CYP3A4 mRNA nor enzyme activity. Target prediction was performed by gas chromatography-mass spectrometry, allowing simultaneous separation and quantification of nine late cholesterol intermediates. Experiments indicated that human sterol Δ(7)-reductase (DHCR7) is the major target of LK-980 (34-fold increase of 7-dehydrocholesterol), whereas human sterol Δ(14)-reductase (DHCR14), human sterol Δ(24)-reductase (DHCR24), and human sterol C5-desaturase (SC5DL) represent minor targets. In the absence of purified enzymes, we used the mathematical model of cholesterol synthesis to evaluate whether indeed more than a single enzyme is inhibited. In silico inhibition of only DHCR7 modifies the flux of cholesterol intermediates, resulting in a sterol profile that does not support experimental data. Partial inhibition of the DHCR14, DHCR24, and SC5DL steps, in addition to DHCR7, supports the experimental sterol profile. In conclusion, we provide experimental and computational evidence that LK-980, a novel inhibitor from the late portion of cholesterol synthesis, inhibits primarily DHCR7 and to a lesser extent three other enzymes from this pathway.

The effect of combination therapy of allicin and fenofibrate on high fat diet-induced vascular endothelium dysfunction and liver damage in rats

Background

It is designed to investigate the effects of combination therapy of allicin and fenofibrate on the endothelial and liver functions in rats with hyperlipidemia.

Methods

The healthy male Wistar rats fed high fat diet were treated with fenofibrate (80 mg/kg per day) alone, allicin (60 mg/kg per day) alone and a lower dasage of combined therapy (allicin 20 mg/kg per day and fenofibrate 30 mg/kg per day) respectively for 8 weeks. The serum levels of cholesterol, triglyceride, nitrogen oxidative, alanine transferase (ALT) and aspartate transferase (AST) were determined. Acetylcholine-induced endothelium-dependent vascular relaxation (EDVR) of aorta rings was tested, and the morphologic changes of liver tissue were observed.

Results

Compared with high fat diet control, fenofibrate alone or the combined therapy increased remarkably the levels of high density lipoprotein respectively (P < 0.05). Both single and combined therapy of fenofibrate and allicin significantly enhanced the levels of NO (P < 0.01 or P < 0.05), but the combined therapy had greatest high EDVR responses (P < 0.01). Furthermore, the reduced levels of ALT and AST were significantly obvious in the combined therapy groups (P < 0.01 or P < 0.05). In addition, the lower dosage of combined therapy significantly ameliorated severe fatty degeneration of liver cells occurred in the high fat diet fed rat although the single fenofibrate treatment showed spotty necrosis of liver cells and bile duct expansion.

Conclusion

Combination therapy with allicin and fenofibrate can effectively enhance the protective effects on endothelial function and reduce the hepatic damage in rats with hyperlipidemia.

Combination therapy for treatment or prevention of atherosclerosis: focus on the lipid-RAAS interaction

Large clinical trials demonstrate that control of blood pressure or hyperlipidemia reduces risk for cardiovascular events by approximately 30%. Factors that may further reduce remaining risk are not definitively established. One potential target is atherosclerosis, a crucial feature in the pathogenesis of cardiovascular diseases whose development is determined by multiple mechanism including complex interactions between endothelial dysfunction and insulin resistance. Reciprocal relationships between endothelial dysfunction and insulin resistance as well as cross-talk between hyperlipidemia and the rennin-angiotensin-aldosterone system may contribute to development of atherosclerosis. Therefore, one appealing strategy for prevention or treatment of atherosclerosis may be to simultaneously address several risk factors with combination therapies that target multiple pathogenic mechanisms. Combination therapy with statins, peroxisome proliferators-activated receptor agonists, and rennin-angiotensin-aldosterone system blockers demonstrate additive beneficial effects on endothelial dysfunction and insulin resistance when compared with monotherapies in patients with cardiovascular risk factors. Additive beneficial effects of combined therapy are mediated by both distinct and interrelated mechanisms, consistent with both pre-clinical and clinical investigations. Thus, combination therapy may be an important concept in developing more effective strategies to treat and prevent atherosclerosis, coronary heart disease, and co-morbid metabolic disorders characterized by endothelial dysfunction and insulin resistance.

Drug interaction potential of 2-((3,4-dichlorophenethyl)(propyl)amino)-1-(pyridin-3-yl)ethanol (LK-935), the novel nonstatin-type cholesterol-lowering agent

The widely prescribed lipid-lowering statins are considered to be relatively safe drugs. However, the risk of severe myopathy and drug interactions as a consequence of statin therapy provides a challenge for development of novel cholesterol-lowering agents, targeting enzymes other than HMG-CoA reductase. The novel pyridylethanol-(phenylethyl)amine derivative, (2-((3,4-dichlorophenethyl)(propyl)-amino)-1-(pyridin-3-yl)ethanol (LK-935), blocking lanosterol 14alpha-demethylase, was demonstrated to efficiently reduce cholesterol biosynthesis. The drug interaction potential of LK-935 was investigated and compared with that of atorvastatin and rosuvastatin in primary human hepatocytes. Clear evidence was provided for the induction of CYP3A4 by LK-935. LK-935 was proved to be a potent human pregnane X receptor (hPXR) activator as a prerequisite for the transcriptional activation of CYP3A4 gene; however, the rapid metabolism of LK-935 in primary hepatocytes prevented maximal CYP3A4 induction. Therefore, the induction of CYP3A4 by LK-935 may be prone to mild or negligible drug interactions. However, because CYP3A4 and also CYP2C9 play a significant role in LK-935 metabolism, the inhibition of these cytochromes P450 by coadministered drugs may lead to some increase in the LK-935 concentration required for the potent induction of CYP3A4. Rosuvastatin was found to increase human constitutive androstane receptor (hCAR)-mediated transcription of CYP3A4, CYP2C9, and CYP2B6 genes, predicting the consequent potential for drug interactions with several coadministered drugs. Activation of hCAR and hPXR by atorvastatin and the subsequent induction of not only CYP2B6 and CYP3A4 but also of CYP2C9 present an additional target by which atorvastatin, a widely used cholesterol-lowering drug, can modify the kinetics of numerous drugs.

Does reversal of oxidative stress and inflammation provide vascular protection?

Chronic inflammation is a pathogenic feature of atherosclerosis and cardiovascular disease mediated by substances including angiotensin II, proinflammatory cytokines, and free fatty acids. This promotes generation of reactive oxygen species in vascular endothelial cells and smooth muscle cells, which mediate injury through several mechanisms. Reciprocal relationships between endothelial dysfunction and insulin resistance as well as cross-talk between hyperlipidaemia and the renin-angiotensin-aldosterone system (RAAS) at multiple levels contribute importantly to a variety of risk factors. Therefore, combination therapy that simultaneously addresses multiple mechanisms for the pathogenesis of atherosclerosis is an attractive emerging concept for slowing progression of atherosclerosis. Combined therapy with statins, peroxisome proliferator-activated receptors, and RAAS blockade demonstrates additive beneficial effects on endothelial dysfunction and insulin resistance when compared with monotherapies in patients with cardiovascular risk factors due to both distinct and interrelated mechanisms. These additive beneficial effects of combined therapies are consistent with laboratory and recent clinical studies. Thus, combination therapy may be an important paradigm for treating and slowing progression of atherosclerosis, coronary heart disease, and co-morbid metabolic disorders characterized by endothelial dysfunction and insulin resistance.

Combination therapy with fenofibrate, a peroxisome proliferator-activated receptor alpha agonist, and simvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, on experimental traumatic brain injury

We and others have demonstrated that fibrates [peroxisome proliferator-activated receptor (PPAR)alpha agonists] and statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) exerted neuroprotective and pleiotropic effects in experimental models of traumatic brain injury (TBI). Because the combination of statins and fibrates synergistically enhanced PPARalpha activation, we hypothesized that the combination of both drugs may exert more important and/or prolonged beneficial effects in TBI than each alone. In this study, we examined the combination of fenofibrate with simvastatin, administered 1 and 6 h after injury, on the consequences of TBI. First, our dose-effect study demonstrated that the most efficient dose of simvastatin (37.5 mg/kg) reduced post-traumatic neurological deficits and brain edema. Then, the effects of the combination of fenofibrate (50 mg/kg) and simvastatin (37.5 mg/kg), given p.o. at 1 and 6 h after TBI, were evaluated on the TBI consequences in the early and late phase after injury. The combination exerted more sustained neurological recovery-promoting and antiedematous effects than monotherapies, and it synergistically decreased the post-traumatic brain lesion. Furthermore, a delayed treatment given p.o. at 3 and 8 h after TBI with the combination was still efficient on neurological deficits induced by TBI, but it failed to reduce the brain edema at 48 h. The present data represent the first demonstration that the combination of fenofibrate and simvastatin exerts prolonged and synergistic neuroprotective effects than each drug alone. Thus, these results may have important therapeutic significance for the treatment of TBI.