Full-length transcriptome analysis and identification of genes involved in asarinin and aristolochic acid biosynthesis in medicinal plant Asarum sieboldii.

Asarum sieboldii, a well-known traditional Chinese medicinal herb, is used for curing inflammation and ache. It contains both the bioactive ingredient asarinin and the toxic compound aristolochic acid. To address further breeding demand, genes involved in the biosynthetic pathways of asarinin and aristolochic acid should be explored. Therefore, the full-length transcriptome of A. sieboldii was sequenced using PacBio Iso-Seq to determine the candidate transcripts that encode the biosynthetic enzymes of asarinin and aristolochic acid. In this study, 63 023 full-length transcripts were generated with an average length of 1371 bp from roots, stems, and leaves, of which 49 593 transcripts (78.69%) were annotated against public databases. Furthermore, 555 alternative splicing (AS) events, 10 869 long noncoding RNAs (lncRNAs) as well as their 11 291 target genes, and 17 909 simple sequence repeats (SSRs) were identified. The data also revealed 97 candidate transcripts related to asarinin metabolism, of which six novel genes that encoded enzymes involved in asarinin biosynthesis were initially reported. In addition, 56 transcripts related to aristolochic acid biosynthesis were also identified, including CYP81B. In summary, these transcriptome data provide a useful resource to study gene function and genetic engineering in A. sieboldii.

Genome mining and biosynthesis of the Acyl-CoA:cholesterol acyltransferase inhibitor beauveriolide I and III in Cordyceps militaris.

Ascomycete fungi Cordyceps are widely used in traditional Chinese medicine, and numerous investigations have been carried out to uncover their biological activities. However, primary researches on the physiological effects of Cordyceps were committed using crude extracts. At present, there are only a few compounds which were comprehensively characterized from Cordyceps, partial owing to the low production. In order to scientifically take advantage of Cordyceps, we used the strategy of genome mining to discover bioactive compounds from Cordyceps militaris. We found the putative biosynthetic gene cluster of the acyl-CoA:cholesterol acyltransferase inhibitor beauveriolides in the genome of C. militaris, and produced the compounds by heterologous expression in Aspergillus nidulans. Production of beauveriolide I and III also was detected in both ferment mycelia and fruiting bodies of C. militaris. The possible biosynthetic pathway was proposed. Our studies unveil the active compounds of C. militaris against atherosclerosis and Alzheimer's disease and provide the enzyme resources for the biosynthesis of new cyclodepsipeptide molecules.

A Metabolic Dependency for Host Isoprenoids in the Obligate Intracellular Pathogen Rickettsia parkeri Underlies a Sensitivity to the Statin Class of Host-Targeted Therapeutics.

Gram-negative bacteria in the order Rickettsiales have an obligate intracellular growth requirement, and some species cause human diseases such as typhus and spotted fever. The bacteria have evolved a dependence on essential nutrients and metabolites from the host cell as a consequence of extensive genome reduction. However, it remains largely unknown which nutrients they acquire and whether their metabolic dependency can be exploited therapeutically. Here, we describe a genetic rewiring of bacterial isoprenoid biosynthetic pathways in the Rickettsiales that has resulted from reductive genome evolution. Furthermore, we investigated whether the spotted fever group Rickettsia species Rickettsia parkeri scavenges isoprenoid precursors directly from the host. Using targeted mass spectrometry, we found that infection caused decreases in host isoprenoid products and concomitant increases in bacterial isoprenoid metabolites. Additionally, we report that treatment of infected cells with statins, which inhibit host isoprenoid synthesis, prohibited bacterial growth. We show that growth inhibition correlates with changes in bacterial size and shape that mimic those caused by antibiotics that inhibit peptidoglycan biosynthesis, suggesting that statins lead to an inhibition of cell wall synthesis. Altogether, our results describe a potential Achilles' heel of obligate intracellular pathogens that can potentially be exploited with host-targeted therapeutics that interfere with metabolic pathways required for bacterial growth.IMPORTANCE Obligate intracellular pathogens, which include viruses as well as certain bacteria and eukaryotes, are a subset of infectious microbes that are metabolically dependent on and unable to grow outside an infected host cell because they have lost or lack essential biosynthetic pathways. In this study, we describe a metabolic dependency of the bacterial pathogen Rickettsia parkeri on host isoprenoid molecules that are used in the biosynthesis of downstream products, including cholesterol, steroid hormones, and heme. Bacteria make products from isoprenoids, such as an essential lipid carrier for making the bacterial cell wall. We show that bacterial metabolic dependency can represent a potential Achilles' heel and that inhibiting host isoprenoid biosynthesis with the FDA-approved statin class of drugs inhibits bacterial growth by interfering with the integrity of the cell wall. This work supports the potential to treat infections by obligate intracellular pathogens through inhibition of host biosynthetic pathways that are susceptible to parasitism.

Sea buckthorn seed oil reduces blood cholesterol and modulates gut microbiota.

Sea buckthorn seed oil (SBSO) has been used as a functional food in the prevention of heart diseases. The present study investigates the effects of SBSO on blood cholesterol and the gut microbiota in hypercholesterolemia hamsters. Four groups of hamsters (n = 8 each) were given one of four diets, namely a non-cholesterol control diet (NCD), a high-cholesterol control diet (HCD) containing 0.1% cholesterol, and an HCD diet with sea buckthorn seed oil replacing 50% lard (SL) or replacing 100% lard (SH). Feeding SL and SH diets could reduce blood total cholesterol by 20-22%. This was accompanied by the down-regulation of the gene expression of acyl-CoA:cholesterol acyltransferase 2 (ACAT2), microsomal triacylglycerol transport protein (MTP), and ATP-binding cassette transporter8 (ABCG8). SBSO supplementation also increased the production of intestinal short-chain fatty acids and fecal outputs of neutral sterols. Metagenomic analysis demonstrated that feeding SL and SH diets could favorably modulate the relative abundance of Bacteroidales_S24-7_group, Ruminococcaceae, and Eubacteriaceae. It was therefore concluded that SBSO was effective in reducing blood cholesterol in hypercholesterolemic hamsters via increasing intestinal cholesterol excretion and promoting the growth of SCFA-producing bacteria.

Hypocholesterolemic Effects of Expeller-Pressed and Solvent-Extracted Fruit Seed Oils and Defatted Pomegranate Seed Meals.

Consumptions of fruit seed oils and meals could potentially improve cardiovascular health by reducing plasma total cholesterol and low-density lipoprotein (LDL). The study objective was to compare the effectiveness of expeller-pressed and solvent-extracted grape, tomato, pomegranate seed oils, and defatted pomegranate meals in lowering plasma and hepatic cholesterol using hamster models. Hamsters were fed with fruit seed oils (FSO), defatted pomegranate seed meals (PDM), or control diets. After a 3-week feeding period, plasma total triglycerides of treatment diets were significantly lower. FSO also reduced total, very-low-density lipoprotein- (VLDL), and LDL-cholesterols, while PDM only lowered VLDL-cholesterols. Decreases in low-density and high-density lipoproteins (LDL/HDL) ratios were also observed in most treatments. In liver, triglycerides, total, and free cholesterol levels did not vary between control and treatments. There were no significant differences in lipid modulating properties between solvent-extracted and expeller-pressed oils. In conclusion, partial replacements of saturated fat in high-fat diets with tomato, pomegranate, and grape seed oils could effectively reduce plasma triglyceride levels and improve HDL/LDL ratios.

Soybean germ oil reduces blood cholesterol by inhibiting cholesterol absorption and enhancing bile acid excretion.

Health benefits of soybean germ oil have not yet been fully explored. The present study examined the blood cholesterol-lowering activity of soybean germ oil and the underlying mechanisms in hypercholesterolemic hamsters. Forty hamsters were randomly assigned into five groups and fed a non-cholesterol diet, a high cholesterol diet and one of three high cholesterol diets containing 0.50% cholestyramine, 4.75% soybean germ oil, and 9.50% soybean germ oil, respectively, for 6 weeks. The result showed that soybean germ oil significantly decreased plasma cholesterol by 18.5-31.5%, which was accompanied by 28.3-62.7% increase in excretion of fecal neutral sterols and bile acids. The effect was mediated by down-regulation of intestinal Niemann-Pick C1-like 1 protein (NPC1L1) and up-regulation of liver cholesterol-7α-hydroxylase (CYP7A1). We concluded that soybean germ oil favorably modulated the blood cholesterol concentration by inhibiting cholesterol absorption through inhibiting gene expression of NPC1L1 and by enhancing bile acid excretion via promoting gene expression of CYP7A1.

Effect of traditional and modern culinary processing, bioaccessibility, biosafety and bioavailability of eritadenine, a hypocholesterolemic compound from edible mushrooms.

Eritadenine is a hypocholesterolemic compound that is found in several mushroom species such as Lentinula edodes, Marasmius oreades, and Amanita caesarea (1.4, 0.7 and 0.6 mg per g dry weight, respectively). It was synthesized during all developmental stages, being present in higher concentrations in the skin of shiitake fruiting bodies. When subjected to traditional cooking, grilling followed by frying were more adequate methodologies than boiling or microwaving to maintain its levels. Modern culinary processes such as texturization (with agar-agar) and spherification (with alginate) also interfered with its release. Grilling and gelling using gelatin enhanced eritadenine's bioaccessibility in an in vitro digestion model. An animal model (where male and female rats were administered 21 and 10 mg per kg animal per day of eritadenine) indicated that intake of the compound was safe under these concentrations; it reached the liver and reduced the atherogenic index (TC/HDL) in rat sera. Thus, it might be used to design a functional food.

Lactobacillus curvatus KFP419 and Leuconostoc mesenteroides subsp. mesenteroides KDK411 Isolated from Kimchi Ameliorate Hypercholesterolemia in Rats.

Western-style diets increase the risk for cardiovascular diseases. It is suggested that the risk could be prevented by lowering cholesterol concentrations in blood. In the present study, hypocholesterolemic effects of the probiotics isolated from kimchi (Lactobacillus curvatus KFP419, Leuconostoc paramesenteroides KJP421, and Leuconostoc mesenteroide subsp. mesenteroides KDK411) were investigated in hypercholesterolemia-induced rats. There was no difference in growth performance between the rats fed high cholesterol diet (HCD) and normal diet (ND). However, blood total cholesterol, low-density lipoprotein cholesterol, and hepatic cholesterol were elevated by the HCD compared to ND, and those concentrations were decreased by dietary supplementation of KFP419 and KDK411. It was concomitant with an increase in fecal excretion of neutral sterols (cholesterol, coprostanol, and coprostanone) in the rats fed HCD compared to ND and was even greater with KDK411 supplementation. These findings indicate that probiotics L. curvatus KFP419 and L. mesenteroide subsp. mesenteroides KDK411 isolated from kimchi ameliorate hypercholesterolemia in rats by assimilating and excreting cholesterol in feces.

Evaluation of the hypocholesterolemic effect and prebiotic activity of a lentil (Lens culinaris Medik) extract.

SCOPE: The aim of our work was to produce a hydroalcoholic extract of lentils and to examine (a) the hypocholesterolemic action in an animal model, by studying the plasma cholesterol level and the concentration of bile acids in the feces; (b) the potential prebiotic effect, by conducting an in vitro culture fermentation experiment and assessing the level of SCFAs in the feces of rats. METHODS AND RESULTS: Lentil extract (LE) was obtained by extracting lentils with a solution of H2 0/EtOH (70/30 v/v) for 3 h, and the content of main nutrients was determined. After 71 days of diet-induced hypercholesterolemia in rats, LE reduced the cholesterol level of rats of 16.8% (p < 0.05) and increased the level of bile acids in the feces of rats (p < 0.01). LE revealed the same prebiotic activity of inulin and good bifidogenic activity, inasmuch as it enhanced the growth of Bifidobacterium spp. by 3 log (p < 0.05). The concentration of SCFAs in the feces of rats fed with LE increased during the time of the study. CONCLUSION: This new hydroalcoholic extract obtained from lentils was shown to possess hypocholesterolemic and prebiotic properties, and could have interesting applications in the field of nutraceuticals.

Effects of Karela (Bitter Melon; Momordica charantia) on genes of lipids and carbohydrates metabolism in experimental hypercholesterolemia: biochemical, molecular and histopathological study.

BACKGROUND: Hypercholesterolemia is a serious diseases associated with type-2 diabetes, atherosclerosis, cardiovascular disorders and liver diseases. Humans seek for safe herbal medication such as karela (Momordica charantia/bitter melon) to treat such disorders to avoid side effect of pharmacotherapies widely used. METHODS: Forty male Wistar rats were divided into four equal groups; control group with free access to food and water, cholesterol administered group (40 mg/kg BW orally); karela administered group (5 g /kg BW orally) and mixture of cholesterol and karela. The treatments continued for 10 weeks. Karela was given for hypercholesterolemic rats after 6 weeks of cholesterol administration. Serum, liver and epididymal adipose tissues were taken for biochemical, histopathological and genetic assessments. RESULTS: Hypercholesterolemia induced a decrease in serum superoxide dismutase (SOD), catalase, reduced glutathione (GSH) and an increase in malondialdehyde (MDA) levels that were ameliorated by karela administration. Hypercholesterolemia up regulated antioxidants mRNA expression and altered the expression of carbohydrate metabolism genes. In parallel, hypercholesterolemic groups showed significant changes in the expression of PPAR-alpha and gamma, lipolysis, lipogenesis and cholesterol metabolism such as carnitine palmitoyltransferase-1 (CPT-1). Acyl CoA oxidase (ACO), fatty acids synthase (FAS), sterol responsible element binding protein-1c (SREBP1c), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR) and cholesterol 7α-hydroxylase (CYP7A1) at hepatic and adipose tissue levels. Interestingly, Karela ameliorated all altered genes confirming its hypocholesterolemic effect. Histopathological and immunohistochemical findings revealed that hypercholesterolemia induced hepatic tissue changes compared with control. These changes include cholesterol clefts, necrosis, karyolysis and sever congestion of portal blood vessel. Caspase-3 immunoreactivity showed positive expression in hepatic cells of hypercholesterolemic rats compared to control. All were counteracted and normalized after Karela administration to hypercholesterolemic group. CONCLUSION: Current findings confirmed that karela is a potential supplement useful in treatment of hypercholesterolemia and its associated disorders and is good for human health.

Design strategies of oxidosqualene cyclase inhibitors: Targeting the sterol biosynthetic pathway.

Targeting the sterol biosynthesis pathway has been explored for the development of new bioactive compounds. Among the enzymes of this pathway, oxidosqualene cyclase (OSC) which catalyzes lanosterol cyclization from 2,3-oxidosqualene has emerged as an attractive target. In this work, we reviewed the most promising OSC inhibitors from different organisms and their potential for the development of new antiparasitic, antifungal, hypocholesterolemic and anticancer drugs. Different strategies have been adopted for the discovery of new OSC inhibitors, such as structural modifications of the natural substrate or the reaction intermediates, the use of the enzyme's structural information to discover compounds with novel chemotypes, modifications of known inhibitors and the use of molecular modeling techniques such as docking and virtual screening to search for new inhibitors. This review brings new perspectives on structural insights of OSC from different organisms and reveals the broad structural diversity of OSC inhibitors which may help evidence lead compounds for further investigations with various therapeutic applications.

Cholesterol-Lowering Activity of Tartary Buckwheat Protein.

Previous research has shown that Tartary buckwheat flour is capable of reducing plasma cholesterol. The present study was to examine the effect of rutin and Tartary buckwheat protein on plasma total cholesterol (TC) in hypercholesterolemia hamsters. In the first animal experiment, 40 male hamsters were divided into four groups fed either the control diet or one of the three experimental diets containing 8.2 mmol rutin, 8.2 mmol quercetin, or 2.5 g kg-1 cholestyramine, respectively. Results showed that only cholestyramine but not rutin and its aglycone quercetin decreased plasma TC, which suggested that rutin was not the active ingredient responsible for plasma TC-lowering activity of Tartary buckwheat flour. In the second animal experiment, 45 male hamsters were divided into five groups fed either the control diet or one of the four experimental diets containing 24% Tartary buckwheat protein, 24% rice protein, 24% wheat protein, or 5 g kg-1 cholestyramine, respectively. Tartary buckwheat protein reduced plasma TC more effectively than cholestyramine (45% versus 37%), while rice and wheat proteins only reduced plasma TC by 10-13%. Tartary buckwheat protein caused 108% increase in the fecal excretion of total neutral sterols and 263% increase in the fecal excretion of total acidic sterols. real-time polymerase chain reaction and Western blotting analyses showed that Tartary buckwheat protein affected the gene expression of intestinal Niemann-Pick C1-like protein 1 (NPC1L1), acyl CoA:cholesterol acyltransferase 2 (ACAT2), and ATP binding cassette transporters 5 and 8 (ABCG5/8) in a down trend, whereas it increased the gene expression of hepatic cholesterol-7α -hydroxylase (CYP7A1). It was concluded that Tartary buckwheat protein was at least one of the active ingredients in Tartary buckwheat flour to lower plasma TC, mainly mediated by enhancing the excretion of bile acids via up-regulation of hepatic CYP7A1 and also by inhibiting the absorption of dietary cholesterol via down-regulation on intestinal NPC1L1, ACAT2 and ABCG5/8.

Microalgal Fatty Acids and Their Implication in Health and Disease.

BACKGROUND: The fatty acids of seed plants and microalgae stored in triglyceride are all produced in the plastid and incorporated into triglycerides by a complex biochemical exchange between the plastid envelope and the endoplasmic reticulum. The oils of seed plants provide the basis for vegetal fat production and the microalgal fats represent an important part of the basal food web of the marine environment. The health-promoting properties of these various sources of fats and in particular the long-chain polyunsaturated fatty acids of marine microalgae are widely recognized. The omega-3 fatty acids are known to have benefits on health and disease. Indeed, alpha-linolenic, eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) are linked to the regulation of mechanisms involved in numerous biological functions associated with cardiovascular disease and cancer prevention. Most EPA and DHA sources for human nutrition are provided by decreasing global stocks of fish. This is one of the reasons why industrial research has been directed towards more sustainable sources of these "marine" lipids. The synthesis of fatty acids and triglycerides are in many respects similar in higher plants and marine algae, but there are also important differences. CONCLUSION: This mini-review covers the biochemistry of fatty acid and lipid synthesis in marine microalgae, and the potential health impact of the different fats is also discussed.

Promotion of classic neutral bile acids synthesis pathway is responsible for cholesterol-lowing effect of Si-miao-yong-an decoction: Application of LC-MS/MS method to determine 6 major bile acids in rat liver and plasma.

Si-miao-yong-an decoction (SMYAD), a traditional Chinese medicine formula, significantly reduced plasma TC, LDL-c levels and increased HDL-c level in hyperlipidemia rats. Liver function test and tissue section examination indicated that SMYAD improved liver function and reduced fat accumulation in hyperlipidemia rat liver. A LC-MS/MS method was established and well validated to evaluate major bile acids derived from cholesterol metabolism through the classic neutral pathway and the alternative acidic pathway (cholic acid, chenodeoxycholic acid and their taurine and glycine conjugates) in liver and plasma. Increased total 6 bile acids concentrations in both liver and plasma were observed after oral administration of 12g/kg/d, 24g/kg/d and 36g/kg/d of SMYAD in a dose dependent manner which contributed to eliminate of cholesterol. Cholic acid, taurocholic acid and glycocholic acid act as the main products of bile acid classic neutral synthesis pathway and show sharp increase (p<0.01) after treatment of SMYAD at dosage of 24-36g/kg/d. For liver samples, taurocholic acid level act as the largest growth section, while in plasma samples, cholic acid act as the largest growth section after SMYAD treatment, compared with Model group. By contrast, the main products of alternative acidic pathway (chenodeoxycholic acid and its glycine and taurine conjugates) show no significant increase after treatment of SMYAD. In conclusion, the cholesterol lowing effect of SMYAD may be related with the accelerated transformation of cholesterol into bile acids through the classic neutral pathway.

Hypocholesterolaemic Activity of Lupin Peptides: Investigation on the Crosstalk between Human Enterocytes and Hepatocytes Using a Co-Culture System Including Caco-2 and HepG2 Cells.

Literature indicates that peptic and tryptic peptides derived from the enzymatic hydrolysis of lupin protein are able to modulate cholesterol metabolism in human hepatic HepG2 cells and that part of these peptides are absorbed in a small intestine model based on differentiated human Caco-2 cells. In this paper, a co-culture system, including Caco-2 and HepG2 cells, was investigated with two objectives: (a) to verify whether cholesterol metabolism in HepG2 cells was modified by the peptides absorption through Caco-2 cells; (b) to investigate how lupin peptides influence cholesterol metabolism in Caco-2 cells. The experiments showed that the absorbed peptides, not only maintained their bioactivity on HepG2 cells, but that this activity was improved by the crosstalk of the two cells systems in co-culture. In addition, lupin peptides showed a positive influence on cholesterol metabolism in Caco-2 cells, decreasing the proprotein convertase subtilisin/kexin type 9 (PCSK9) secretion.

An Ester of ß-Hydroxybutyrate Regulates Cholesterol Biosynthesis in Rats and a Cholesterol Biomarker in Humans.

In response to carbohydrate deprivation or prolonged fasting the ketone bodies, ß-hydroxybutyrate (ßHB) and acetoacetate (AcAc), are produced from the incomplete ß-oxidation of fatty acids in the liver. Neither ßHB nor AcAc are well utilized for synthesis of sterols or fatty acids in human or rat liver. To study the effects of ketones on cholesterol homeostasis a novel ßHB ester (KE) ((R)-3-hydroxybutyl (R)-3-hydroxybutyrate) was synthesized and given orally to rats and humans as a partial dietary carbohydrate replacement. Rats maintained on a diet containing 30-energy % as KE with a concomitant reduction in carbohydrate had lower plasma cholesterol and mevalonate (-40 and -27 %, respectively) and in the liver had lower levels of the mevalonate precursors acetoacetyl-CoA and HMG-CoA (-33 and -54 %) compared to controls. Whole liver and membrane LDL-R as well as SREBP-2 protein levels were higher (+24, +67, and +91 %, respectively). When formulated into a beverage for human consumption subjects consuming a KE drink (30-energy %) had elevated plasma ßHB which correlated with decreased mevalonate, a liver cholesterol synthesis biomarker. Partial replacement of dietary carbohydrate with KE induced ketosis and altered cholesterol homeostasis in rats. In healthy individuals an elevated plasma ßHB correlated with lower plasma mevalonate.

Atheroprotective effects of (poly)phenols: a focus on cell cholesterol metabolism.

Collated observations from several epidemiological studies have demonstrated that dietary intake of (poly)phenols from nuts, coffee, cocoa, grapes, and berries may protect against the development of atherosclerosis. Whereas this beneficial activity has previously been linked mainly to antioxidant or anti-inflammatory properties, recently emerging data suggest mechanisms by which (poly)phenolic substances can modulate cellular lipid metabolism, thereby mitigating atherosclerotic plaque formation. In this review, both experimental studies and clinical trials investigating the atheroprotective effects of the most relevant dietary (poly)phenols are critically discussed.

Mechanism of action of anti-hypercholesterolemia drugs and their resistance.

Coronary artery disease is one of the leading causes of death worldwide. One of the significant causes of this disease is hypercholesterolemia which is the result of various genetic alterations that are associated with the accumulation of specific classes of lipoprotein particles in plasma. A number of drugs are used to treat hypercholesterolemia like statin, fibrate, bile acid sequestrants, niacin, ezetimibe, omega-3 fatty acids and natural extracts. It has been observed that these drugs show diverse response in different individuals. The present review explains the mechanism of action of these drugs as well as mechanism of its lesser effectiveness or resistance in some individuals. There are various identified genetic variations that are associated with diversity in the drugs response. Therefore, present study helps to understand the ethiology of drug mechanism and resistance developed against drugs used to treat hypercholesterolemia.

Effects of dietary plant meal and soya-saponin supplementation on intestinal and hepatic lipid droplet accumulation and lipoprotein and sterol metabolism in Atlantic salmon (Salmo salar L.).

Altered lipid metabolism has been shown in fish fed plant protein sources. The present study aimed to gain further insights into how intestinal and hepatic lipid absorption and metabolism are modulated by plant meal (PM) and soya-saponin (SA) inclusion in salmon feed. Post-smolt Atlantic salmon were fed for 10 weeks one of four diets based on fishmeal or PM, with or without 10 g/kg SA. PM inclusion resulted in decreased growth performance, excessive lipid droplet accumulation in the pyloric caeca and liver, and reduced plasma cholesterol levels. Intestinal and hepatic gene expression profiling revealed an up-regulation of the expression of genes involved in lipid absorption and lipoprotein (LP) synthesis (apo, fatty acid transporters, microsomal TAG transfer protein, acyl-CoA cholesterol acyltransferase, choline kinase and choline-phosphate cytidylyltransferase A), cholesterol synthesis (3-hydroxy-3-methylglutaryl-CoA reductase) and associated transcription factors (sterol regulatory element-binding protein 2 and PPARγ). SA inclusion resulted in reduced body pools of cholesterol and bile salts. The hepatic gene expression of the rate-limiting enzyme in bile acid biosynthesis (cytochrome P450 7A1 (cyp7a1)) as well as the transcription factor liver X receptor and the bile acid transporter abcb11 (ATP-binding cassette B11) was down-regulated by SA inclusion. A significant interaction was observed between PM inclusion and SA inclusion for plasma cholesterol levels. In conclusion, gene expression profiling suggested that the capacity for LP assembly and cholesterol synthesis was up-regulated by PM exposure, probably as a compensatory mechanism for excessive lipid droplet accumulation and reduced plasma cholesterol levels. SA inclusion had hypocholesterolaemic effects on Atlantic salmon, accompanied by decreased bile salt metabolism.

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

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