Drug treatment of combined hyperlipidemia

Sorghum extract exerts cholesterol-lowering effects through the regulation of hepatic cholesterol metabolism in hypercholesterolemic mice

The purpose of this study is to investigate that sorghum extract (SE) exerts cholesterol-lowering effects through the regulation of hepatic cholesterol metabolism-related protein expression. C57BL/6 mice were fed a modified AIN-93G diet (NC) with saline, or a modified AIN-93G diet with 2% cholesterol and 0.25% cholic acid with either saline (HC) or 600 mg SE/kg body weight (HC-SE). Levels of total cholesterol and triglycerides in serum and liver were significantly lower in HC-SE than in HC. The expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase, sterol regulatory elementary binding protein2 and fatty acid synthase were significantly lower, whereas phosphorylated AMP-activated protein kinase expression was significantly higher in HC-SE than in HC. Cholesterol 7-α hydroxylase expression was also significantly higher in mice given SE than in those given HC. These results suggest that the cholesterol-lowering effect of SE may be related to the regulation of hepatic cholesterol metabolism in this mouse model.

Deciphering molecular mechanism underlying hypolipidemic activity of echinocystic Acid

Our previous study showed that a triterpene mixture, consisting of echinocystic acid (EA) and oleanolic acid (OA) at a ratio of 4 : 1, dose-dependently ameliorated the hyperlipidemia and atherosclerosis in rabbits fed with high fat/high cholesterol diets. This study was aimed at exploring the mechanisms underlying antihyperlipidemic effect of EA. Molecular docking simulation of EA was performed using Molegro Virtual Docker (version: 4.3.0) to investigate the potential targets related to lipid metabolism. Based on the molecular docking information, isotope labeling method or spectrophotometry was applied to examine the effect of EA on the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, acyl-CoA:cholesterol acyltransferase (ACAT), and diacylglycerol acyltransferase (DGAT) in rat liver microsomes. Our results revealed a strong affinity of EA towards ACAT and DGAT in molecular docking analysis, while low binding affinity existed between EA and HMG-CoA reductase as well as between EA and cholesteryl ester transfer protein. Consistent with the results of molecular docking, in vitro enzyme activity assays showed that EA inhibited ACAT and DGAT, with IC₅₀ values of 103 and 139 μM, respectively, and exhibited no significant effect on HMG-CoA reductase activity. The present findings suggest that EA may exert hypolipidemic effect by inhibiting the activity of ACAT and DGAT.

Titrating lovaza from 4 to 8 to 12 grams/day in patients with primary hypertriglyceridemia who had triglyceride levels >500 mg/dl despite conventional triglyceride lowering therapy

Background

Omega-3 fatty acids are important in treatment of severe primary hypertriglyceridemia (HTG). In 15 patients with severe primary HTG (TG >500 mg/dl despite conventional TG lowering therapy), we assessed efficacy-safety of sequential monthly treatment with Lovaza, 4 to 8 to 12 g/day.

Methods

With TG >500 mg/dl despite Type V diet, hyperinsulinemia and diabetes control, and fibric acids, Lovaza (4 g/d) was added for 1 month, and if TG remained >500 mg/dl, increased to 8 g/d for 1 month, and then to 12 g/d for 1 month, and subsequently reduced to 4 g/day for 4 months.

Results

Primary HTG, median TG 884 mg/dl, 14 men, 1 woman, all white, age 50 ± 7 years, 12 non-diabetic, 3 with stable diabetes control. Weight and diet held stable throughout. In 5 patients, after 1, 2, and 3 months on 4 g/day, TG fell <500, mean 1390 to 234 (−83%, p<.0001), to 135 (−90%, p<.0001), and 158 mg/dl (−89%, p<.0001), with a negative TG slope, p=.0013. Non-HDLC fell from 320 to 177 (−45%, p=.001), to 152 (−53%, p=.0002), and to 163 (−49%, p=.0004), with a negative slope, p=.01. In 10 patients, with Lovaza increased from 4 to 8 to 12 g, 3 failed to respond. In 7 of these 10 patients, TG fell 37% from 1075 to 672 on 4 g (p=.006), to 577 on 8 g (−46%, p=.0009), and to 428 mg/dl (−60%, p<.0001) on 12 g/day, with a negative TG slope, p=.0018. TG on 12 g/day was lower than on 8 g/day, p =.03. Non-HDLC fell from 245 to 217 mg/dl (−11%) on 4 g/day, to 203 (−17%, p=.01) on 8 g/day, and to 192 (−22%, p=.003) on 12 g/day, with a negative slope, p=.016. Compared to pre-Lovaza baseline, no abnormal measures developed in safety tests. The 4, 8, and 12 g/d Lovaza doses were well tolerated.

Conclusion

Titration of Lovaza from 4 to 8 to 12 g/d safely offers an effective way to lower TG beyond conventional 4 g therapy.

Diagnosis and treatment of severe hypertriglyceridemia

Severe hypertriglyceridemia is associated with acute pancreatitis and can be a manifestation of lipoprotein lipase (LPL) deficiency. It is associated with a spectrum of disorders, ranging from heterozygous LPL deficiency allied with environmental factors to rare severe cases of homozygous LPL deficiency. The genes associated with reduced LPL activity include LPL, its cofactor apoC-2, a controlling protein apoA-5 and the LPL receptor GPI-HBP1. The effects of mutations are exacerbated by environmental factors such as diet, pregnancy and insulin resistance. Treatment of clinical LPL deficiency is by ultra-low-fat diet along with the use of fibrates, omega-3 fatty acids, niacin, statins and insulin-sensitizing therapies, depending on the extent of residual LPL activity. Novel therapies that target lipoprotein particle assembly through the antisense oligonucleotides or by interference with triglyceride-loading microsomal transport protein inhibitors offer new potential options for treating hypertriglyceridemia.

Aqueous extract of Gleditsia sinensis Lam. fruits improves serum and liver lipid profiles and attenuates atherosclerosis in rabbits fed a high-fat diet

ETHNOPHARMACOLOGICAL RELEVANCE

Gleditsia sinensis Lam. has been used in the traditional Chinese medicine as a chief ingredient of many polyherbal formulations for the treatment of obesity and thrombosis.

AIM OF THE STUDY

To evaluate the effects of Gleditsia sinensis Lam. fruit aqueous extract (GAE) on hyperlipidemia and atherosclerosis in Japanese white rabbits on a high fat diet.

MATERIALS AND METHODS

Rabbits were divided into four groups: the normal control with a normal diet, and high-fat diet-fed model group and GAE-treated groups supplemented with GAE (6 or 12 mg/kg/day, p.o.), respectively. The groups fed high-fat diets were given i.v. with bovine serum albumin (BSA) on the 4th week to induce atherosclerosis. The serum lipid profile, including triglycerides (TG), total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C), was determined on the 0th, 4th, 8th and 14th week, respectively. And the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) were measured simultaneously. At the end of the experiment, the rabbits were sacrificed, and the atherosclerotic plaques as well as the histopathological changes of aorta and liver were assessed by oil-red or HE staining, respectively, and the aorta and liver lipid profiles were also assayed.

RESULTS

Results showed that the prophylactic treatment with GAE could significantly decrease the lipid levels of serum, aorta and liver, attenuate aortic atherosclerosis and improve aortic remodeling without the significant liver and muscle toxicity.

CONCLUSION

The present findings suggest that GAE can effectively attenuate the atherosclerotic at least through anti-hyperlipidemic activity and thus has the therapeutic potential in treating hyperlipidemia-related cardiovascular diseases.

Acute pancreatitis in pregnancy: an overview

Acute pancreatitis is rare in pregnancy but it is associated with increased incidence of maternal and fetal mortality. It should be considered in the differential diagnosis of upper quadrant abdominal pain with or without nausea and vomiting. The commonest identified causes of acute pancreatitis in pregnancy are gallstones, alcohol and hypertriglyceridemia. The main laboratory finding is increased amylase activity. Appropriate investigations include ultrasound of the right upper quadrant and measurement of serum triglycerides and ionized calcium. Management of gallstone pancreatitis is controversial, although laparoscopic cholecystectomy and endoscopic retrograde cholangiopancreatography (ERCP) are often used and may be associated with lower complication rates. In hypertriglyceridemia-induced acute pancreatitis ω-3 fatty acids and even therapeutic plasma exchange can be used. We also discuss preventive measures.

Comparison of fibrate, ezetimibe, low- and high-dose statin therapy for the dyslipidemia of the metabolic syndrome in a mouse model

BACKGROUND AND AIM

The treatment-of-choice for the optimal management of the dyslipidemia of the metabolic syndrome (MetS) is not clearly defined. We compared the efficacy of 4 drug regimes for the management of this dyslipidemia in a mouse model.

MATERIALS AND METHODS

A total of 60 C57Bl6 mice comprised the study group. The first 10 received standard mouse food for the whole experiment (control group). The remaining 50 mice received atherogenic diet for 14 weeks until the development of the MetS. The mice were then divided into 5 groups: the 1st group continued receiving atherogenic diet, while the other 4 groups received atherogenic diet plus ezetimibe (10 mg/kg per day), fenofibrate (100 mg/kg per day), low-dose atorvastatin (10 mg/kg per day), or high-dose (40 mg/kg per day) atorvastatin, respectively, for another 8 weeks.

RESULTS

High-dose atorvastatin treatment achieved the best lipid profile compared with low-dose atorvastatin, ezetimibe, and fibrate therapy. The lipid profile of mice receiving atherogenic diet plus high-dose atorvastatin treatment was similar with mice on regular chow.

CONCLUSIONS

High-dose atorvastatin treatment resulted in optimization of the lipid profile in the presence of a high-fat atherogenic diet in a mouse model. Our results suggest that high-dose atorvastatin treatment may be the optimal treatment option for the dyslipidemia associated with MetS. Nevertheless, verification of these results in humans is required before any definite conclusions can be drawn.

Properties of an oral preparation containing a chitosan salt

The 2-(4-chlorophenoxy)-2-methylpropionic acid (CMP) salt of chitosan (CS), CS-CMP, and that of a CS derivative (CP), were prepared and their ability to adsorb bile acids investigated. CS-CMP and CP-CMP rapidly adsorbed taurocholate (TCA) and glycocholate (GCA) when these bile acids were present together in the medium, with simultaneous release of CMP. A secondary bile acid, taurodeoxycholate, was preferentially adsorbed over TCA and GCA. Alginate gel beads containing CS-CMP did not differ from CS-CMP alone in their manner of bile acids take up. Furthermore, oral administration of CS-CMP to rats resulted in decreased serum cholesterol and triacylglycerol levels for two weeks. Therefore, CS-CMP, as well as a vehicle containing CS-CMP, might be a useful agent with which to treat hyperlipidemia.

Lipid-Altering Therapies and the Progression of Atherosclerotic Disease

Lipids play a key role in the progression of atherosclerosis, and lipid-lowering therapies have been studied for 30 years in coronary disease. Measurement of the progression of atherosclerosis through carotid intima-media thickness, coronary mean lumen diameter, and, mostly recently, intravascular ultrasound is generally accepted. This article reviews the role of lipid-lowering therapies in changing the rate of atherosclerosis progression in the coronary and carotid circulations. Statins are the primary therapy used to reduce atherosclerosis and cardiovascular events, including strokes and transient ischemic attacks, and have benefits in reducing events in patients undergoing carotid endarterectomy. In contrast, data for other agents, including fibrates and nicotinic acid, in reducing the progression of atherosclerosis are less extensive and not as well known. There is increasing interest in optimizing the whole lipid profile, as this might deliver extra benefits over and above statin therapy alone. Initial proof of this concept has recently come from studies that measured the progression of atherosclerosis and showed that adding nicotinic acid to statin therapy and, more directly, infusion of high-density lipoprotein-like particles reduced progression and indeed might induce regression of the disease. It is likely that the management of significant carotid stenosis will become ever more drug focused and will be customized to the lipid profile of each patient with intervention reserved only for late-stage symptomatic disease.

Statin-fibrate combination: therapy for hyperlipidemia: a review

Statins and fibrates are well-established treatments for hyperlipidaemias and the prevention of vascular events. However, fibrate + statin therapy has been restricted following early reports of rhabdomyolysis that mainly involved gemfibrozil, originally with bovastatin, and recently, with cerivastatin. Despite this limitation, several reports describing combination therapy have been published. This review considers these studies and the relevant indications and contraindications. Statin + fibrate therapy should be considered if monotherapy or adding other drugs (e.g. cholesterol absorption inhibitors, omega-3 fatty acids ornicotinic acid) did not achieve lipid targets or is impractical. Combination therapy should be hospital-based and reserved for high-risk patients with a mixed hyperlipidaemia characterised by low density lipoprotein cholesterol (LDL) >2.6 mmol/l(100 mg/dl, high density lipoprotein cholesterol (HDL) <1.0 mmol/l (40 mg/dl) and/or triglycerides> 5.6 mmol/l (500 mg/dl. These three 'goals' are individually mentioned in guidelines. Patients should have normal renal, liver and thyroid function tests and should not be receiving therapy with cyclosporine, protease inhibitors or drugs metabolised through cytochrome P450 (especially 3A4). Combination therapy is probably best conducted using drugs with short plasma half-lives; fibrates should be prescribed in the morning and statins at night to minimise peak dose interactions. Both drug classes should be progressively titated from low doses. Regular (3-monthly) monitoring of liver function and creatine kinase is required. In conclusion, fibrate + statin therapy remains an option in high-risk patents. However, long-term studies involving safety monitoring and vascular endpoints are required to demonstrate the efficacy of this regimen.

Statins and renal function

Renal disease is often associated with an increased risk of vascular events. Moreover, an accelerated form of atherosclerosis commonly occurs in these patients. The reasons for these associations are not clearly defined but include the widespread presence of several established risk factors (eg, dyslipidemia, hypertension, and diabetes). Other predictors of atherosclerotic disease may also be abnormally elevated (eg, homocysteine, fibrinogen, and lipoprotein a). In addition, there is evidence that impaired renal function per se predicts vascular risk. Despite this high-risk background, the potential benefit of treatment with statins has not been widely investigated in these patients. The present review considers the evidence (experimental and clinical) that statins exert beneficial effects in patients with different types of renal disease. This includes improved renal function, decreased microalbuminuria, and a fall in blood pressure. Statins may also improve renal allograft survival. The potential mechanisms mediating these effects are considered. The interactions between statins and several risk factors that may be present in patients with impaired renal function are also considered. There is an urgent need to define the role of statins in these high-risk patients. Which is the statin of choice? This question is relevant because impaired renal function can interfere with statin pharmacokinetics. Furthermore, other drugs administered to these patients may cause serious interactions with statins.

Beyond LDL-C--the importance of raising HDL-C

Epidemiological studies have established that low levels of high-density lipoprotein cholesterol (HDL-C) are associated with an increased risk of coronary heart disease (CHD). Recent studies have demonstrated that low HDL-C levels, and high triglycerides and total cholesterol levels are independent predictors of CHD, and that the combination of these lipid abnormalities increases the risk of coronary events. In lipid-modifying intervention studies, agents that raise HDL-C levels have been shown to reduce the incidence of major coronary events. The VA-HIT study consisted of patients with low-density lipoprotein cholesterol (LDL-C) levels similar to those recommended by several guidelines but with low levels of HDL-C. This trial demonstrated that raising HDL-C levels with gemfibrozil reduced the risk of CHD-related events. While the mechanisms by which HDL-C exerts its anti-atherogenic effects have yet to be fully elucidated, its role in the reverse transport of cholesterol and the beneficial effects on endothelial function are plausible explanations for these actions. Although LDL-C reduction is the primary goal in the treatment of dyslipidaemia, current guidelines recognise low HDL-C levels as a major risk factor for CHD. Indeed, the NCEP ATP III guidelines suggest that the treatment of isolated low HDL-C levels in CHD patients or individuals with CHD risk equivalents should be considered. The differing abilities of statins to raise HDL-C levels may be an important factor when making treatment decisions. New lipid-modifying drugs with beneficial effects on both HDL-C and LDL-C levels would be desirable additions to the currently available therapeutic options.