Biochemistry and Nanomechanical Properties of Human Colon Cells upon Simvastatin, Lovastatin, and Mevastatin Supplementations: Raman Imaging and AFM Studies.

One of the most important areas of medical science is oncology, which is responsible for both the diagnostics and treatment of cancer diseases. Over the years, there has been an intensive development of cancer diagnostics and treatment. This paper shows the comparison of normal (CCD-18Co) and cancerous (CaCo-2) cell lines of the human gastrointestinal tract on the basis of nanomechanical and biochemical properties to obtain information on cancer biomarkers useful in oncological diagnostics. The research techniques used were Raman spectroscopy and imaging and atomic force microscopy (AFM). In addition, the studies also included the effect of the statin compounds─mevastatin, lovastatin, and simvastatin─and their influence on biochemical and nanomechanical changes of cell properties using Raman imaging and AFM techniques. The cytotoxicity of statins was determined using XTT tests.

New cytotoxic secondary metabolites against human pancreatic cancer cells from the Hypericum perforatum endophytic fungus Aspergillus terreus.

Four new compounds, including two lovastatin analogues, terrstatins A and B (1 and 2), and a pair of butenolide derivatives, (±)-asperteretone F (3a/3b), along with eleven known compounds (4-14), were isolated from the Hypericum perforatum endophytic fungus Aspergillus terreus. Their structures and absolute configurations were determined based on extensive spectroscopic analysis, experimental and calculated electronic circular dichroism (ECD) analysis. All isolates were evaluated for cytotoxic activities against five human cancer cell lines, and compounds 3a/3b and 6 showed potential cytotoxic activities against human pancreatic cancer cells, including AsPC-1, SW1990 and PANC-1 cells, with IC50 values ranging from 1.2 to 15.6 µM.

Isoflavones enhance pharmacokinetic exposure of active lovastatin acid via the upregulation of carboxylesterase in high-fat diet mice after oral administration of Xuezhikang capsules.

Xuezhikang capsule (XZK) is a traditional Chinese medicine that contains lovastatin (Lv) for hyperlipidemia treatment, although it has fewer side effects than Lv. However, the pharmacokinetic mechanisms contributing to its distinct efficacy and low side effects are unclear. Mice were fed a high-fat diet (HFD) for 6 weeks to induce hyperlipidemia. We first conducted the pharmacokinetic studies in HFD mice following oral administration of Lv (10 mg/kg, i.g.) and found that HFD remarkably decreased the active form of Lv (the lovastatin acid, LvA) exposure in the circulation system, especially in the targeting organ liver, with a declined conversion from Lv to LvA, whereas the Lv (responsible for myotoxicity) exposure in muscle markedly increased. Then we compared the pharmacokinetic profiles of Lv in HFD mice after the oral administration of XZK (1200 mg/kg, i.g.) or an equivalent dose of Lv (10 mg/kg, i.g.). A higher exposure of LvA and lower exposure of Lv were observed after XZK administration, suggesting a pharmacokinetic interaction of some ingredients in XZK. Further studies revealed that HFD promoted the inflammation and inhibited carboxylesterase (CES) activities in the intestine and the liver, thus contributing to the lower transformation of Lv into LvA. In contrast, XZK inhibited the inflammation and upregulated CES in the intestine and the liver. Finally, we evaluated the effects of monacolins and phytosterols, the fractional extracts of isoflavones, on inflammatory LS174T or HepG2 cells, which showed that isoflavones inhibited inflammation, upregulated CES, and markedly enhanced the conversion of Lv into LvA. For the first time, we provide evidence that isoflavones and Lv in XZK act in concert to enhance the efficacy and reduce the side effects of Lv.

Efficacy and safety of long-term treatment with statins for coronary heart disease: A Bayesian network meta-analysis.

BACKGROUND AND AIMS: Our study aims to evaluate the efficacy and safety of long-term treatment of statins for coronary heart disease (CHD). METHODS: Efficacy outcomes included changes in blood lipids, risk of CHD mortality and all-cause mortality. Safety outcomes were evaluated by the risk of adverse events (AE). Bayesian network meta-analysis was used to compare the direct and indirect effects between different statins. RESULTS: The systematic review showed that levels of blood lipids decreased during statin treatment. High dose of atorvastatin was the most obvious treatment for the reduction of blood lipids. Network meta-analysis showed that statins were significantly more effective than the control in reducing the risk of CHD mortality (Odds Ratio (OR) 0.69, 95% CI 0.61-0.77) and all-cause mortality (OR 0.84, 95% CI 0.80-0.87). In terms of reducing the risk of CHD morality, fluvastatin (77.3%), atorvastatin (72.3%) and lovastatin (68.4%) had higher cumulative probability than other statins, which were more effective treatments for the reduction of CHD morality. In terms of reducing all-cause mortality, atorvastatin (78.6%), fluvastatin (77.1%) and pitavastatin (74.1%) had higher cumulative probability than other statins, which were more effective treatment for reducing the all-cause mortality. Compared with placebo, statins increased the incidence risk of muscle disease (OR 1.05, 95% CI 1.00-1.10) and kidney disease (OR 1.11, 95% CI 1.05-1.72). CONCLUSIONS: Statins significantly reduced levels of blood lipids, with a high dose of atorvastatin being the most effective in blood-lipid level modification. Statins reduced the risk of CHD mortality and all-cause mortality, with atorvastatin and fluvastatin being the most effective in reducing the risk of CHD mortality and all-cause mortality. Statins increased the risk of muscle disease and kidney damage.

Induction of secondary metabolism of Aspergillus terreus ATCC 20542 in the batch bioreactor cultures.

Cultivation of Aspergillus terreus ATCC 20542 in a stirred tank bioreactor was performed to induce the biosynthesis of secondary metabolites and provide the bioprocess-related insights into the metabolic capabilities of the investigated strain. The activation of biosynthetic routes was attempted by the diversification of process conditions and growth media. Several strategies were tested, including the addition of rapeseed oil or inulin, changing the concentration of nitrogen source, reduction of chlorine supply, cultivation under saline conditions, and using various aeration schemes. Fifteen secondary metabolites were identified in the course of the study by using ultra-high performance liquid chromatography coupled with mass spectrometry, namely mevinolinic acid, 4a,5-dihydromevinolinic acid, 3α-hydroxy-3,5-dihydromonacolin L acid, terrein, aspulvinone E, dihydroisoflavipucine, (+)-geodin, (+)-bisdechlorogeodin, (+)-erdin, asterric acid, butyrolactone I, desmethylsulochrin, questin, sulochrin, and demethylasterric acid. The study also presents the collection of mass spectra that can serve as a resource for future experiments. The growth in a salt-rich environment turned out to be strongly inhibitory for secondary metabolism and the formation of dense and compact pellets was observed. Generally, the addition of inulin, reducing the oxygen supply, and increasing the content of nitrogen source did not enhance the production of examined molecules. The most successful strategy involved the addition of rapeseed oil to the chlorine-deficient medium. Under these conditions, the highest levels of butyrolactone I, asterric acid, and mevinolinic acid were achieved and the presence of desmethylsulochrin and (+)-bisdechlorogeodin was detected in the broth. The constant and relatively high aeration rate in the idiophase was shown to be beneficial for terrein and (+)-geodin biosynthesis.

Mevastatin reduces cartilage degradation in rabbit experimental osteoarthritis through inhibition of synovial inflammation.

OBJECTIVE: To examine the therapeutic efficacy of an HMG-CoA reductase inhibitor (statin) in rabbit osteoarthritis (OA) in vitro and in vivo. METHODS: In the presence or absence of mevastatin, rabbit chondrocytes and synoviocytes were incubated with Interleukin-1beta (IL-1beta), and analyzed by biochemical methods. Thirty-two mature rabbits that underwent bilateral anterior cruciate ligament transaction (ACLT) received six consecutive weekly intra-articular injections of mevastatin at three different concentrations or a control solution. All animals were sacrificed 6 weeks after ACLT, and the knee joints were assessed by morphological, histological, immunohistochemical, and biochemical methods. RESULTS: Mevastatin inhibited IL-1beta stimulation of gene expression of monocyte chemoattractant protein-1 (MCP-1) and matrix-metalloproteinases 3 (MMP-3), in synoviocytes but not chondrocytes. The levels of MCP-1 and MMP-3 productions in synoviocytes were significantly reduced by statin-treatment. In rabbit with OA, intra-articular injection of mevastatin significantly reduced cartilage degradation, as assessed by morphological and histological examinations. Synovial tissues of knees treated with mevastatin showed less severe inflammatory responses with reduced thickness of synovial cell lining and less infiltration of subsynovial CD68+monocyte lineage cells compared to untreated control knees. Relative mRNA expressions of MCP-1, IL-1beta, MMP-3, and MMP-13 were reduced in synovial tissues, but not articular cartilage, of knees treated with mevastatin compared with untreated control knees. CONCLUSION: During the development of experimental OA, intra-articular administration of HMG-CoA reductase inhibitor (statin) reduces inflammatory cell infiltration and matrix-degrading enzyme expression, thus limiting cartilage degradation.

Berberine decreases PCSK9 expression in HepG2 cells.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) post-transcriptionally downregulates the low-density lipoprotein receptor (LDLR) by binding to the receptor's epidermal growth factor repeat A on the cell surface and shuttling the LDLR to the lysosomes for degradation. Mutations in the PCSK9 gene have been shown to cause either hypo- or hypercholesterolemia. Here we investigated the effect of berberine, a natural plant extract, on PCSK9 expression in HepG2 cells. RESULTS: Berberine decreases PCSK9 mRNA and protein levels in a time- and dose-dependent manner. This was not due to increased degradation of PCSK9 mRNA but most likely due to a decreased transcription of the PCSK9 gene. We also show that a combination of berberine and mevastatin increases LDLR mRNA and protein levels, while suppressing the increase in PCSK9 mRNA levels caused by mevastatin alone. CONCLUSION: Berberine may be a useful supplement to statin treatment due to its effects on PCSK9 mRNA and protein levels.

Synergistic antiproliferative effects of gamma-tocotrienol and statin treatment on mammary tumor cells.

Statins are potent inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMGCoA) reductase and display anticancer activity, but their clinical use is limited by their high-dose toxicity. Similarly, gamma-tocotrienol, an isoform of vitamin E, also reduces HMGCoA reductase activity and displays potent anticancer activity. Studies were conducted to determine if combined low dose treatment of gamma-tocotrienol with individual statins resulted in a synergistic antiproliferative effect on neoplastic mouse +SA mammary epithelial cells. Treatment with 3-4 microM gamma-tocotrienol or 2-8 microM simvastatin, lovastatin or mevastatin alone resulted in a significant decrease, whereas treatment with 10-100 microM pravastatin had no effect on +SA cell growth. However, combined treatment of subeffective doses (0.25 or 10 microM) of individual statins with 0.25-2.0 microM gamma-tocotrienol resulted in a dose-responsive synergistic inhibition in +SA cell proliferation. Additional studies showed that treatment with subeffective doses of individual statins or gamma-tocotrienol alone had no effect, whereas combined treatment of these compounds resulted in a relatively large decrease in intracellular levels of phosphorylated (activated) MAPK, JNK, p38, and Akt. These findings strongly suggest that combined low dose treatment of gamma-tocotrienol with individual statins may have potential value in the treatment of breast cancer without causing myotoxicity that is associated with high dose statin treatment.

Red mold rice ameliorates impairment of memory and learning ability in intracerebroventricular amyloid beta-infused rat by repressing amyloid beta accumulation.

Amyloid beta (Abeta) peptide related to the onset of Alzheimer's disease (AD) damaged neurons and further resulted in dementia. Monascus-fermented red mold rice (RMR), a traditional Chinese medicine as well as health food, includes monacolins (with the same function as statins) and multifunctional metabolites. In this study, ethanol extract of RMR (RE) was used to evaluate neuroprotection against Abeta40 neurotoxicity in PC12 cells. Furthermore, the effects of dietary administration of RMR on memory and learning abilities are confirmed in an animal model of AD rats infused with Abeta40 into the cerebral ventricle. During continuous Abeta40 infusion for 28 days, the rats of test groups were administered RMR or lovastatin. Memory and learning abilities were evaluated in the water maze and passive avoidance tasks. After sacrifice, cerebral cortex and hippocampus were collected for the examination of AD risk factors. The in vitro results clearly indicate that RE provides stronger neuroprotection in rescuing cell viability as well as repressing inflammatory response and oxidative stress. RMR administration potently reverses the memory deficit in the memory task. Abeta40 infusion increases acetylcholinesterase activity, reactive oxygen species, and lipid peroxidation and decreases total antioxidant status and superoxide dismutase activity in brain, but these damages were potently reversed by RMR administration, and the protection was more significant than that with lovastatin administration. The protection provided by RMR is able to prevent Abeta fibrils from being formed and deposited in hippocampus and further decrease Abeta40 accumulation, even though Abeta40 solution was infused into brain continuously.

Identification and chemical profiling of monacolins in red yeast rice using high-performance liquid chromatography with photodiode array detector and mass spectrometry.

Monascus purpureus-fermented rice (red yeast rice) was one of the food supplements that had the ability of lowering the blood-lipid levels, and monacolins have been proved to be main active constituents. In total 14 monacolin compounds such as monacolin K (mevinolin), J, L, M, X, and their hydroxy acid form, as well as dehydromonacolin K, dihydromonacolin L, compactin, 3alpha-hydroxy-3,5-dihydromonacolin L, etc. were identified in red yeast rice, using high-performance liquid chromatography with photodiode array detector and tandem mass spectrometry. A chemical fingerprint profiling method to display bioactive monacolins in red yeast rice was established and could be used for the quality control of the target material and its related products. Ten finish products labeled as red yeast rice from different manufacturers in marketing were traced using the chromatographic chemical profiling method, and the results show that only two of them were similar while the other eight were significantly different from the reference red yeast rice. All of these materials including raw material powder and finished products available were quantified and the contents of monacolins were calculated with reference of monacolin K (mevinolin) as the standard.

Molecular cloning and characterization of CLICK-III/CaMKIgamma, a novel membrane-anchored neuronal Ca2+/calmodulin-dependent protein kinase (CaMK).

During a screen for novel putative Ca(2+)/calmodulin-dependent protein kinase (CaMK)-like CREB kinases (CLICKs), we have cloned a full-length cDNA for CLICK-III/CaMKIgamma, an isoform of the CaMKI family with an extended C-terminal domain ending with CAAX motif (where AA is aliphatic acid). As expected from the similarity of its kinase domain with the other CaMKI isoforms, full activation of CLICK-III/CaMKIgamma required both Ca(2+)/CaM and phosphorylation by CaMKK. We also found that Ca(2+)/cAMP-response element-binding protein (CREB) was a good substrate for CLICK-III/CaMKIgamma, at least in vitro. Interestingly enough, CLICK-III/CaMKIgamma transcripts were most abundant in neurons, with the highest levels in limited nuclei such as the central nucleus of the amygdala (CeA) and the ventromedial hypothalamus. Consistent with the presence of the CAAX motif, CLICK-III/CaMKIgamma was found to be anchored to various membrane compartments, especially to Golgi and plasma membranes. Both point mutation in the CAAX motif and treatment with compactin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, disrupted such membrane localization, suggesting that membrane localization of CLICK-III/CaMKIgamma occurred in a prenylation-dependent way. These findings provide a novel mechanism by which neuronal CaMK activity could be targeted to specific membrane compartments.

Modulation of COX-2 expression by statins in human aortic smooth muscle cells. Involvement of geranylgeranylated proteins.

Cyclooxygenase (COX)-2 and COX-1 play an important role in prostacyclin production in vessels and participate in maintaining vascular homeostasis. Statins are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, which is crucial in cholesterol biosynthesis. Recently, cholesterol-independent effects of statins have been described. In this study, we evaluated the effect of two inhibitors of HMG CoA reductase, mevastatin and lovastatin, on the production of prostacyclin and the expression of COX in human aortic smooth muscle cells. Treatment of cells with 25 microm mevastatin or lovastatin resulted in the induction of COX-2 and increase in prostacyclin production. Mevalonate, the direct metabolite of HMG CoA reductase, and geranylgeranyl-pyrophosphate reversed this effect. GGTI-286, a selective inhibitor of geranylgeranyltransferases, increased COX-2 expression and prostacyclin formation, thus indicating the involvement of geranylgeranylated proteins in the down-regulation of COX-2. Furthermore, Clostridium difficile toxin B, an inhibitor of the Rho GTP-binding protein family, the Rho selective inhibitor C3 transferase, and Y-27632, a selective inhibitor of the Rho-associated kinases, targets of Rho A, increased COX-2 expression whereas the activator of the Rho GTPase, the cytotoxic necrotizing factor 1, blocked interlukin-1alpha-dependent COX-2 induction. These results demonstrate that statins up-regulate COX-2 expression and subsequent prostacyclin formation in human aortic smooth muscle cells in part through inhibition of Rho.

Compactin enhances osteogenesis in murine embryonic stem cells.

Embryonic stem (ES) cells have the capacity to differentiate into various cell types in vitro. In this study, we show that retinoic acid is important for the commitment of ES cells into osteoblasts. Culturing retinoic acid treated ES cells in the presence of the osteogenic supplements ascorbic acid and beta-glycerophosphate resulted in the expression of several osteoblast marker genes, osteocalcin, alkaline phosphatase, and osteopontin. However, there was only a slight amount of mineralized matrix secretion. Addition of bone morphogenic protein-2 or compactin, a drug of the statin family of HMG-CoA reductase inhibitors, resulted in a greatly enhanced formation of bone nodules. Compactin did not modify the expression of osteogenic markers, but at the late stage of differentiation promoted an increase in BMP-2 expression. These results establish ES-cell derived osteogenesis as an effective model system to study the molecular mechanisms by which the statin compactin promotes osteoblastic differentiation and bone nodule formation.

Separate and joint effects of marine oil and simvastatin in patients with combined hyperlipidemia.

Marine oil plus simvastatin is an effective therapy for improving serum triglycerides, non-high-density lipoprotein cholesterol, and high-density lipoprotein cholesterol in patients with combined hyperlipidemia. Concurrent administration does not attenuate the individual effects of either marine oil or simvastatin on the serum lipid profile.

Enhanced myopathy following administration of hypolipidemic agents under urethane anesthesia.

The enhanced effect of urethane anesthesia on the serum creatine kinase (CPK) level following administration of hypolipidemic agents was examined to develop a convenient experimental screening method for drug-induced myopathy. After oral administration of a hypolipidemic agent to rats, 25% urethane solution was infused intravenously at a very low rate using a microinfusion pump. Blood samples were collected 7 h after drug administration and the risk of myopathy was evaluated based on the CPK level. When bezafibrate (BF), simvastatin (SV), or pravastatin (PV) (50-500 mg/kg) was orally administered under urethane infusion, enhanced elevation of the serum CPK level was observed dose dependently for BF and SV, but not for PV. The elevation of serum CPK was much higher with BF than with SV or PV. In addition, when SV or PV (50-500 mg/kg) was coadministered with 50 mg/kg of BF, there was a striking increase in the serum CPK level as compared with the drug alone. Without urethane infusion, no significant elevation in serum CPK level was observed even at a high dose of these hypolipidemic agents. These phenomena suggest that the urethane anesthesia enhanced the elevation of the serum CPK level following administration of hypolipidemic agents. We propose that this method is a simple and speedy screening test for drug-induced myopathy.

A prospective clinical trial comparing the treatment of idiopathic membranous nephropathy and nephrotic syndrome with simvastatin and diet, versus diet alone.

Of 17 patients with idiopathic membranous nephropathy (IMN) and nephrotic syndrome, 9 were allocated to treatment with simvastatin (an HMG CoA-reductase inhibitor) and low cholesterol diet, and 8 to diet alone. At entry, the treatment and control groups did not differ in mean serum creatinines, chromium-labelled EDTA clearances, urinary protein/creatinine ratios, serum albumins, and lipid profiles. The mean follow up period (+/- SEM) in the treated group was 19.3 (+/- 4.4) months compared with 16.6 (+/- 5.9) months in the control group. At the end of the trial the fall in chromium-labelled EDTA clearances was similar (-1.27 versus -1.28 mls/min/months/1.73 m2) in the treatment and control groups respectively. The mean (+/- SEM) total and LDL-cholesterol had gone from 10.5 (+/- 0.94) and 8.02 (+/- 1) mmol/l to 5.2 (+/- 0.49) and 3.47 (+/- 0.44) respectively in the treated patients. Additionally the mean (+/- SEM) albumin and urinary protein/creatinine ratio went from 25.6 (+/- 2.4) gm/l and 0.52 (+/- 0.09) gm/mmol to 45.5 (+/- 2.8) and 0.13 (+/- 0.04) respectively. There was little change in total and LDL-cholesterol; albumin and urinary protein/creatinine ratio in the control group. This study supports the observation that lowering serum cholesterol in the nephrotic syndrome reduces proteinuria and increases serum albumin levels. No difference in the rate of decline in renal function could be demonstrated.

The new paradigm for coronary artery disease: altering risk factors, atherosclerotic plaques, and clinical prognosis.

The old paradigm states that the greater the stenosis, the greater the risk of cardiac events. Revascularization procedures are the only effective approach to improving prognosis associated with coronary artery disease. In contrast, on the basis of the new paradigm, the nature of the plaque determines the risk of acute cardiovascular events. Dangerous plaques have a lipid-rich core with surrounding inflammation and a thin friable overlying fibrous cap, but they usually appear innocuous on angiography. Effective risk factor modification stabilizes the dangerous plaques and is associated with prompt improvement in endothelial dysfunction and a substantial decrease in the risk of acute cardiovascular events and death.

Japanese and American reports of randomized trials: differences in the reporting of adverse effects.

We sought to identify differences in the description of adverse drug experiences in reports of randomized clinical trials (RCTs) from the United States and Japan, using diclofenac and simvastatin as test drugs. Reports were identified in Medline (Index Medicus 1966-1990), EMBASE (Excerpta Medica 1974-1990), JAPICDOC (1979-1990), and JOIS-III (JMEDICINE 1980-1990). In each search keywords describing study design were paired with the drugs' generic names, chemical names, and development numbers. Twenty-seven U.S. reports (18 for diclofenac and 9 for simvastatin) and 22 Japanese reports (17 for diclofenac and 5 for simvastatin) identified in these four databases were selected for review. For each paper we identified the relation of the article to the data (preliminary, primary, and secondary reports, reviews), the means of identifying adverse reactions, the principal outcomes of the trials, and a variety of descriptive measures relating to study design, authorship, and elements of presentation. With few exceptions, Japanese reports were not indexed in English-language databases, and studies from the United States were not carried out in the Japanese databases. The Japanese literature consisted exclusively of primary reports of clinical trials, whereas the U.S. literature was dominated by review articles and secondary reports of data from trials not fully published elsewhere. Japanese reports contained more detail on adverse experiences but reported principally those attributed to the drugs by attending clinicians. U.S. reports by contrast offered little detail but tended to include all adverse experiences, whether or not clinically attributed to drugs. A preponderance of U.S. articles reported significant differences between drugs in safety or treatment efficacy, whereas only one third of the Japanese articles did so for the same agents. Reports from both countries offered few details of the methods used to gather information on adverse drug experiences, and as a result the reported absolute frequencies of such events are difficult to compare between trials or to generalize to other settings. In conclusion, the reporting of adverse reactions in clinical trials is inadequate in both the United States and Japanese literature. The shortcomings are complementary in that reports of U.S. trials contain insufficient detail and Japanese reports do not interpret or synthesize experience. Clinical research into drug safety in both countries could be improved through the adoption of simple standards of clarity and consistency in the monitoring and reporting of drug adverse effects.

Fish oil supplementation in patients with heterozygous familial hypercholesterolemia.

Familial hypercholesterolemia is associated with premature coronary heart disease. In patients with familial hypercholesterolemia, monotherapy with hydroxymethylglutaril coenzyme. A reductase inhibitors rarely achieves the goal of desirable low-density lipoprotein levels. Epidemiological studies suggest that populations with a high dietary intake of marine n3 fatty acids are protected against coronary heart disease. Hepatic synthesis and secretion of very low density lipoproteins are reduced during fish oil supplementation while other effects on lipid and lipoprotein metabolism are controversial. Fourteen patients affected by familial heterozygous hypercholesterolemia on chronic treatment with simvastatin were enrolled in a double blind, placebo controlled, randomized crossover trial that evaluated the effect of fish oil ethyl ester (Esapent, 5.1 g/day) on lipid and lipoprotein serum concentrations. Total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides, apoprotein B, apoprotein AI, lipoprotein (a) did not show any significant variation during the four week treatment period with fish oil ethyl ester. The present data suggest that the possible favourable influence of fish oil on the progression of atherosclerosis in these high-risk patients might involve mechanisms which are different from lipid metabolism.

Biochemical changes and morphological alterations of liver and kidney in hamsters after administration of the HMG-coenzyme A reductase inhibitor, simvastatin: prevention and reversibility by mevalonate.

The present study analyses the effects of simvastatin, a specific inhibitor of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA reductase) in male Syrian hamsters fed a standard diet or a diet supplemented with 0.12% cholesterol and 20% coconut oil. In hamsters fed the standard diet, gastric administration of simvastatin (10 mg/kg/day) during 12 days was found to be lethal and to have hepatotoxic and nephrotoxic effects. This toxicity was exacerbated in hamsters fed a hyperlipidaemic diet and was preceded by a progressive anorexia and loss of body weight. Marked elevations in serum aspartate and alanine aminotransferase activities were associated with the organ lesions. All elevated biochemical changes and morphological alterations were prevented or reversed by coadministration of mevalonate, the product of the HMG-CoA reductase. It is suggested that the dramatic effect of simvastatin could result from depletion of a non-sterol metabolite of mevalonate in spite of a lack of protective effects of farnesol and geranylgeraniol in the following study. The toxicity of simvastatin could indeed result from the low basal activity of HMG-CoA reductase in hamster liver coupled with a prolonged inhibition of mevalonate synthesis.