Hypolipidemic and anti-atherogenic effects of long-term Cholestin (Monascus purpureus-fermented rice, red yeast rice) in cholesterol fed rabbits

Monascus spp. and citrinin: Identification, selection of Monascus spp. isolates, occurrence, detection and reduction of citrinin during the fermentation of red fermented rice

Red fermented rice (RFR) is rice fermented using Monascus spp. This product contains monacolin K, providing health benefits including mitigation of diarrhoea and improving blood circulation. RFR can produce pigments that can act as natural colour and flavouring agents. However, Monascus spp. (a fungal starter to ferment RFR) can also produce the mycotoxin, citrinin (CIT) which is believed to have adverse effects on human health. CIT in RFR has been reported worldwide by using different methods of detection. This review focuses on the production of RFR by solid-state fermentation (SSF) and submerged fermentation (SmF), the occurrence of CIT in RFR, CIT quantification, the factors affecting the growth of Monascus spp., pigments and CIT production in RFR, and possible methods to reduce CIT in RFR. This review will help the food industries, researchers, and consumers understand the risk of consuming RFR, and the possibility of controlling CIT in RFR.

The biological activity and application of Monascus pigments: a mini review

Monascus pigments (MPs), as secondary metabolites of Monascus, are microbial pigments which have been used for thousands of years. MPs are widely used in food industry as food pigments and preservatives, which have the stability of light resistance, high temperature resistance and acid-base change resistance. In addition, the antioxidant, antibacterial, antiviral and anti-tumor biological activities of MPs have also attracted people’s attention. Moreover, Due to the presence of citrinin, the safety of MPs still needs to be discussed and explored. In this paper, the production, biological activity, application in various fields and methods of detection and reduction of citrinin of MPs were reviewed, which provide new insights into the study and safe application related to human different diseases, medicines or health care products with MPs as active substances.

Protective effect and mechanism of Monascus-fermented red yeast rice against colitis caused by Salmonella enterica serotype Typhimurium ATCC 14028

Red yeast rice (RYR), a traditional Chinese fermented food, has the effect of lowering blood lipid and cholesterol, but little information is available about whether RYR can inhibit pathogenic bacterial infection in vivo. The present study explored the effect of RYR on Salmonella enterica-induced intestinal inflammation and gut microbiota dysbiosis in mice as well as the underlying anti-inflammatory mechanism. Results showed that RYR can alleviate S. enterica infection in vivo and Monascus pigments are the main functional components. The analysis of microbiota, gene expression profile and serological immunology revealed that RYR can regulate the intestinal flora and increase the relative abundance of beneficial bacteria such as Lactobacillus and Akkermansia. Meanwhile, RYR is also found to regulate the expression of pro-inflammatory factors and tight junction-related genes to inhibit the NO and NF-κB-mediated inflammatory response and maintain the integrity of the intestinal barrier. This study provides a new dietary intervention strategy for the prevention of pathogenic bacterial infection.

Effects of Chinese medicines on monacolin K production and related genes transcription of Monascus ruber in red mold rice fermentation

Monacolin K (MK) is a secondary metabolite synthesized by polyketide synthases of Monascus spp. In this study, the combined supplementation of three medicines, including Citri Reticulatae Pericarpium (CRP), Fructus crataegi (FC), and Radix Angelicae Dahuricae (RAD), were mixed with nonglutinous rice and were optimized by response surface methodology to enhance the production of MK in fermented red mold rice (RMR). Under the optimum condition, MK production achieved 3.60 mg/g, which was 41.18% higher than RMR without medicines. The improved MK production was mainly caused by the up-regulated transcription level of mokA, mokB, mokF, mokH, mokI, and mplaeA. Meanwhile, the inhibitory effect of Poria cocos (PC) on MK production (only 0.436 mg/g) was caused by significantly down-regulated transcription of six tested genes. Therefore, this study is beneficial for better understanding of the possible mechanism of enhanced MK production by optimization of fermentation conditions.

Red Yeast Rice: A Systematic Review of the Traditional Uses, Chemistry, Pharmacology, and Quality Control of an Important Chinese Folk Medicine

Red yeast rice (RYR), a Chinese traditional folk medicine produced by the fermentation of cooked rice kernels with a Monascaceae mold, Monascus purpureus, has long been used to treat blood circulation stasis, indigestion, diarrhea, and limb weakness in East Asian countries. This article provides a systematic review of the traditional uses, chemistry, biological activities, and toxicology of RYR to highlight its future prospects in the field of medicine. The literature reviewed for this article was obtained from the Web of Science, Elsevier, SciFinder, PubMed, CNKI, ScienceDirect, and Google Scholar, as well as Ph.D. and M.Sc. dissertations, published prior to July 2019. More than 101 chemical constituents have been isolated from RYR, mainly consisting of monacolins, pigments, organic acids, sterols, decalin derivatives, flavonoids, polysaccharides, and other compounds. Crude extracts of RYR, as well as its isolated compounds, possess broad pharmacological properties with hypolipidemic, anti-atherosclerotic, anti-cancer, neurocytoprotective, anti-osteoporotic, anti-fatigue, anti-diabetic, and anti-hypertensive activities. However, further studies are needed to characterize its diverse chemical constituents and the toxicological actions of the main bioactive compounds. New pharmacological trials addressing the overlooked traditional uses of RYR, such as in the treatment of indigestion and diarrhea, are required.

Monascus spp. used in wheat kernel solid-state fermentations: growth, extrolite production and citrinin cytotoxicity

Monascus fermentation products can be consumed as food or feed supplements or used as food colouring or flavouring agents. In this study, qPCR and Q-TOF LC/MS methods were developed to monitor Monascus ruber and Monascus purpureus growth and extrolite (lovastatin, mevastatin, as well as the regulated mycotoxin, citrinin (CIT)) production, respectively. Wheat kernels were inoculated with one strain of each species during a solid-state fermentation followed over 63 days. Different growth and extrolite production patterns were clearly observed for the 2 tested strains. After 63 days, high lovastatin levels (up to 0.5 mg/g) were reached for M. ruber wheat fermented kernels while M. purpureus only yielded 0.1 mg/g of lovastatin at best, suggesting that M. ruber may be a better candidate for lovastatin production in a wheat-based model. Mevastatin levels were low and stable for both species. However, M. ruber fermented wheat kernels also contained the highest CIT content, up to 4.2 μg/g, i.e. at levels above the regulation threshold set by the European Union. CIT toxicity was then determined in vitro on bovine kidney cells, showing an IC10 of 6.10-4 M. At maximum concentrations encountered during solid-state fermentation, CIT toxicity was very low under chronic exposure.

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.

Protective Effects of Liquiritigenin against Citrinin-Triggered, Oxidative-Stress-Mediated Apoptosis and Disruption of Embryonic Development in Mouse Blastocysts

The mycotoxin citrinin (CTN), a natural contaminant in foodstuffs and animal feeds, exerts cytotoxic and genotoxic effects on various mammalian cells and embryos. A previous investigation by our group revealed potentially hazardous effects of CTN on mouse oocyte maturation and pre- and post-implantation embryo development via the induction of apoptosis. The present study showed that CTN induces apoptosis and inhibits cell proliferation in the inner cell mass of mouse blastocysts. Notably, we observed for the first time that both these effects are suppressed by liquiritigenin (LQ). LQ is a type of flavonoid isolated from Glycyrrhiza radix with several biochemical and pharmacological activities, including antioxidant and anti-inflammatory properties. The preincubation of blastocysts with LQ clearly prevented CTN-induced disruption of pre- and post-implantation embryonic development and fetal weight loss, both in vitro and in vivo. CTN-induced damage processes directly promoted reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential (MMP) and activation of caspase-9 and caspase-3, which were effectively blocked by LQ. Moreover, in an animal model, intravenous injection of dams with CTN (3 mg/kg/day) triggered apoptosis of blastocysts, disruption of embryonic development from the zygote to the blastocyst stage and a decrease in fetal weight. Pre-injection with LQ (5 mg/kg/day) effectively reduced apoptosis and impaired the cytotoxic effects of CTN on development. Our in vivo findings further confirm that CTN exposure via injection has the potential to impair pre- and post-implantation development, leading to apoptosis and the suppression of sequent embryonic development, which can be effectively prevented by LQ.

The Effect of Dietary Replacement of Ordinary Rice with Red Yeast Rice on Nutrient Utilization, Enteric Methane Emission and Rumen Archaeal Diversity in Goats

Twenty castrated Boer crossbred goats were used in the present study with two treatments to examine the effect of dietary replacement of ordinary rice with red yeast rice on nutrient utilization, enteric methane emission and ruminal archaea structure and composition. Two treatment diets contained (DM basis) 70.0% of forage, 21.8% of concentrates and 8.2% of either ordinary rice (control) or red yeast rice (RYR). Nutrient utilization was measured and enteric methane emissions were determined in respiration chambers. Results showed that RYR had significantly lower digestibility of N and organic matter compared to control group. However, feeding red yeast rice did not affect N retention as g/d or a proportion of N intake, and reduced heat production as MJ/d or as a proportion of metabolizable energy intake, thus leading to a higher proportion of metabolizable energy intake to be retained in body tissue. RYR also had significantly lower methane emissions either as g/d, or as a proportion of feed intake. Although feeding red yeast rice had no negative effect on any rumen fermentation variables, it decreased serum contents of total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol. In the present study, 75616 archaeal sequences were generated and clustered into 2364 Operational Taxonomic Units. At the genus level, the predominant archaea in the rumen of goats was Methanobrevibacter, which was significantly inhibited with the supplementation of red yeast rice. In conclusion, red yeast rice is a potential feed ingredient for mitigation of enteric methane emissions of goats. However, caution should be taken when it is used because it may inhibit the digestibility of some nutrients. Further studies are required to evaluate its potential with different diets and animal species, as well as its effects on animal health and food safety.

The blood lipid regulation of Monascus-produced monascin and ankaflavin via the suppression of low-density lipoprotein cholesterol assembly and stimulation of apolipoprotein A1 expression in the liver

BACKGROUND/PURPOSES

Monascin (MS) and ankaflavin (AK) produced by Monascus purpureus NTU 568 were proven to show excellent hypolipidemic effects in our previous studies; however, the mechanism is still unclear.

METHODS

This study used MS, AK, and monacolin K as test substances and performed tests on rats fed high-fat and high-cholesterol diet for 8 weeks. The lipid levels and the related protein levels of the rats were assessed to understand the effects of MS, AK, and monacolin K on lipid metabolism.

RESULTS

MS and AK lowered low-density lipoprotein cholesterol (LDL-C) and preserved high-density lipoprotein cholesterol contents. MS and AK inhibited acetyl-coenzyme A acetyltransferase, microsomal triglyceride transfer protein, and apolipoprotein (apo) B-100 expression, thereby preventing LDL assembly. In addition, enhanced LDL-receptor expression increased the transport of LDL-C to the liver for metabolism. MS and AK also significantly increase apo A1 expression, which facilitates high-density lipoprotein cholesterol formation.

CONCLUSION

Monascus-fermented MS and AK can perform blood lipid regulation via the suppression of LDL-C assembly and stimulation of apo A1 expression in liver.

Isoflavones and phytosterols contained in Xuezhikang capsules modulate cholesterol homeostasis in high-fat diet mice

AIM

Xuezhikang (XZK), an extract of red yeast rice, has been widely used in traditional Chinese medicine to treat cardiovascular disease. Three fractions F1, F2 and F3 (primarily containing isoflavones, monacolins or phytosterols, respectively) are extracted from Xuezhikang capsules. In this study we evaluated the lipid-lowering effects of these fractions and explored the potential mechanisms of actions.

METHODS

Mice treated with a high-fat diet (HFD) were orally administered lovastatin (10 mg·kg(-1)·d(-1)), XZK (1200 mg·kg(-1)·d(-1)), F1 (27.5 mg·kg(-1)·d(-1)), F2 (11.3 mg·kg(-1)·d(-1)) or F3 (35 mg·kg(-1)·d(-1)) for 10 weeks. Lipids were measured using commercial enzymatic kits, and the mRNA and protein levels of genes involved in cholesterol and bile acid homeostasis were evaluated using qRT-PCR and Western blot analysis, respectively.

RESULTS

XZK increased the fecal excretion of lipids and bile acids, reduced serum TC, TG and LDL-C levels by 40%, 55% and 46%, respectively, and increased serum HDL-C by 31%. Administration of F1 repressed serum TC and TG by 24% and 52%, respectively, and elevated hepatic synthesis of CYP7A1. It also increased hepatic elimination of bile acids in the fecal excretions by 79% through upregulating BSEP and downregulating NTCP. Administration of F3 decreased serum TC, TG and LDL-C levels by 33%, 29% and 39%, respectively, and increased serum HDL-C by 28%, significantly reduced intestinal absorption of cholesterol by inhibiting the transcription of NPC1L1, and elevated excretion of TC, FC and CE by 96%, 72% and 101%, respectively. Administration of F2 showed pharmacological effects similar to those of lovastatin.

CONCLUSION

Isoflavones and phytosterols in XZK exert cholesterol-lowering effects in HFD mice through mechanisms that differ from those of lovastatin. Isoflavones and phytosterols act in a complimentary manner: through enhancing the elimination of bile acids and reducing intestinal cholesterol absorption, respectively.

Monascus purpureus-fermented Thai glutinous rice reduces blood and hepatic cholesterol and hepatic steatosis concentrations in diet-induced hypercholesterolemic rats

BACKGROUND

Red yeast rice (RYR) is a fermented product used as a food supplement to promote blood circulation and lower blood cholesterol levels in eastern Asia. Interestingly, monacolin K is the most active compound in RYR that proved to inhibit HMG-CoA reductase in the cholesterol biosynthesis pathway.

METHODS

The hypocholesterolemic effects of oral administration of Thai RYR, produced by fermentation of Thai glutinous rice (Oryza sativa L. var. Niaw San-pah-tawng) with Monascus purpureus CMU 002U, were determined in normal and hypercholesterolemic rats. The rats were divided into six groups, and fed two different kinds of diet. Groups I-II, normal rats fed with a normal diet (SP-diet), were treated with distilled water (SP-control) and 2.0 g/kg/day of RYR extract (SP-2 g). In Groups III-VI, the rats were rendered hypercholesterolemic by feeding them a high fat and cholesterol diet (HFC-diet), and were treated with distilled water (HFC-control), 1.0 g/kg/day (HFC-1 g), 2.0 g/kg/day (HFC-2 g) of RYR extract, and 5.0 mg/kg/day of rosuvastatin (HFC-rosuvastatin) for 30 days, respectively.

RESULTS

The RYR extract significantly decreased the concentrations of serum total cholesterol and low density lipoprotein cholesterol (LDL-C), atherosclerotic index, LDL-C/HDL-C ratio and hepatic cholesterol levels in both HFC-1 g and HFC-2 g groups (p < 0.05) as compared with the HFC-control group, and with no significant change in high density lipoprotein cholesterol (HDL-C) concentrations among all six groups. The reduction of serum TC and LDL-C also paralleled the observed changes in mRNA expressions of the genes involved in cholesterol biosynthesis and homeostasis in the liver. The hypercholesterolemic rats treated with RYR extract were significantly higher in LDLR and HMGR expression, but lower in CYP7A1 expression when compared to the untreated hypercholesterolemic rats (HFC-control) (p < 0.05). The hepatic injuries in hypercholesterolemic rats were also obviously alleviated by RYR extract.

CONCLUSIONS

The extract of Thai RYR possessed potent hypocholesterolemic and anti-atherogenic activities in diet-induced hypercholesterolemic rats. The possible mechanism involving cholesterol-lowering potential of the extract might contribute to its ability to increase LDL-C endocytosis in hepatocyte and to competitively inhibit HMG-CoA reductase, a key enzyme for cholesterol biosynthesis in liver.

Most appropriate animal models to study the efficacy of statins: a systematic review

BACKGROUND

In animal models and clinical trials, statins are reported as effective in reducing cholesterol levels and lowering the risk of cardiovascular diseases. We have aggregated the findings in animal models - mice, rats and rabbits - using the technique of systematic review and meta-analysis to highlight differences in the efficacy of statins.

MATERIALS AND METHODS

We searched Medline and Embase. After examining all eligible articles, we extracted results about total cholesterol and other blood parameters, blood pressure, myocardial infarction and survival. Weighted and standard mean difference random effects meta-analysis was used to measure overall efficacy in prespecified species, strains and subgroups.

RESULTS

We included in systematic review 161 animal studies and we analysed 120 studies, accounting for 2432 animals. Statins lowered the total cholesterol across all species, although with large differences in the effect size: -30% in rabbits, -20% in mice and -10% in rats. The reduction was larger in animals fed on a high-cholesterol diet. Statins reduced infarct volume but did not consistently reduce the blood pressure or effect the overall survival. Few studies considered strains at high risk of cardiovascular diseases or hard outcomes.

CONCLUSIONS

Although statins showed substantial efficacy in animal models, few preclinical data considered conditions mimicking human pathologies for which the drugs are clinically indicated and utilized. The empirical finding that statins are more effective in lowering cholesterol derived from an external source (i.e. diet) conflicts with statin's supposed primary mechanism of action.

A review on the traditional Chinese medicinal herbs and formulae with hypolipidemic effect

Hyperlipidemia, characterized by the abnormal blood lipid profiles, is one of the dominant factors of many chronic diseases such as diabetes, obesity, and cardiovascular diseases (CVD). For the low cost, effectiveness, and fewer side effects, the popularity of using traditional Chinese medicine (TCM) to handle hyperlipidemia is increasing and its role in health care has been recognized by the public at large. Despite the importance of TCM herbs and formulations, there is no comprehensive review summarizing their scientific findings on handling hyperlipidemia. This review summarizes the recent experimental and clinical results of nine representative single Chinese herbs and seven classic TCM formulae that could improve lipid profiles so as to help understand and compare their underlying mechanisms. Most of single herbs and formulae demonstrated the improvement of hyperlipidemic conditions with multiple and diverse mechanisms of actions similar to conventional Western drugs in spite of their mild side effects. Due to increasing popularity of TCM, more extensive, well-designed preclinical and clinical trials on the potential synergistic and adverse side effects of herb-drug interactions as well as their mechanisms are warranted. Hyperlipidemic patients should be warned about the potential risks of herb-drug interactions, particularly those taking anticoagulants and antiplatelet drugs.

Hypocholesterolemic activity of monascus fermented product in the absence of monacolins with partial purification for functional food applications

Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical therapy traditional medication is used as hypocholesterolemic remedy, however, with unfavorable side effects. Recently, Monascus fermented product (MFP) has become a popular hypocholesterolemic natural supplement. In the present study, the hypocholesterolemic activity of Monascus purpureus FTC5391 fermented product ethanolic extract (MFPe) was investigated in hypercholesterolemic rats. Results showed that MFPe not only reduced the serum total cholesterol (TC), LDL-C, TG concentration, and TC/HDL-C ratio but also increased the HDL-C. Further, solid phase extraction (SPE) was carried out to obtain the hypocholesterolemic bioactive fraction. The high polar fraction of SPE increased the HDL-C (42%) and decreased the TC (53.3%), LDL-C (47%), and TG (50.7%) levels as well as TC/HDL-C ratio (69.1%) in serum. The GC-MS results of the active fraction revealed two main compounds, isosorbide and erythritol, which act as coronary vasodilator compounds.

Monascin and ankaflavin have more anti-atherosclerosis effect and less side effect involving increasing creatinine phosphokinase activity than monacolin K under the same dosages

Monacolin K has long been considered a major effective component in the hypolipidemic functions of Monascus . Monacolin K also serves as a well-known hypolipidemic medication, but its side effect myopathy is a concern. Monascin and ankaflavin, the yellow pigments produced by Monascus species, have been proven to possess hypolipidemic functions; however, no studies have compared the hypolipidemic effects of monascin, ankaflavin, and monacolin K under the same dosages. In this study, the equal dosages of monascin, ankaflavin, and monacolin K were oral administrated to hamsters fed a high cholesterol diet for 6 weeks. Comparison of the displayed hypolipidemic and anti-atherosclerosis effects was performed, in addition to an investigation into the inducement of side effect. The results indicated that monascin and ankaflavin were similar to monacolin K in significantly reducing total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) levels in serum and lipid plaque (p < 0.05) in the heart aorta. In addition, ankaflavin achieved the effects of serum TC and TG reduction, with no significant difference as compared to those effects of monacolin K (p > 0.05). However, as compared to monacolin K, ankaflavin possessed more significant effects on the prevention of fatty liver and lipid plaque accumulation in heart aorta. More importantly, monascin significantly enhanced high-density lipoprotein cholesterol (HDL-C) concentrations, while monacolin K displayed the opposite effect. Regarding the side effect, monacolin K also raised elevated creatinine phosphokinase (CPK) activity, which was highly correlated with rhabdomyolysis development, while monascin and ankaflavin did not induce such a side effect. In conclusion, MS and AK had the potential to be developed as hypolipidemic agents without rhabdomyolysis development.

Evaluation of nephrotoxic effects of mycotoxins, citrinin and patulin, on zebrafish (Danio rerio) embryos

Citrinin (CTN) and patulin (PAT) are fungal secondary metabolites which are found in food and feed and showed organotoxicity in mature animals. In this study zebrafish embryos were applied to investigate the developmental toxicity of CTN and PAT on embryonic kidney. In the presence of CTN and PAT, the gross morphology of kidneys from embryos with green fluorescent kidney (wt1b:GFP) was not apparently altered. Histological analysis of CTN-treated embryos indicated cystic glomerular and tubular lesions; a disorganized arrangement of renal cells was also found in the PAT-treated group. From the view point of renal function, dextran clearance abilities of embryos exposed to CTN and PAT were significantly reduced. The damaged renal function caused by CTN could be partially rescued by the administration of pentoxifylline, suggesting the reduction of glomerular blood flow contributes to CTN-induced renal dysfunction. Additionally, CTN induced the expression of proinflammation genes, including COX2a, TNF-α and IL-1β, but failed to modify the levels and distribution of wt1a transcript and Na(+)/K(+)-ATPase protein. In summary, CTN and PAT caused profound nephrotoxicity in histological structure and biological function of zebrafish embryos; the inflammatory pathway and blood rheology may involve in CTN-induced renal impairment.

Development of Monascus fermentation technology for high hypolipidemic effect

Monascus species has been used as the traditional food fungus in Eastern Asia for several centuries. Monascus-fermented products are gradually developed as the popular functional food for the prevention of cardiovascular disease, but we know that culture condition affects the hypolipidemic effect of Monascus-fermented product. In the past, the cholesterol-lowering agent--monacolin K--is regarded as the most important hypolipidemic agent. Two natural yellow pigments--monascin and ankaflavin--are also proven as novel hypolipidemic agents in recent years. However, the hypolipidemic effect of Monascus-fermented product should contribute from monacolin K, monascin, ankaflavin, and other unknown functional ingredients. In addition to hypolipidemic effect, the safety concern of Monascus-fermented product is involved in the levels of mycotoxin--citrinin. The hypolipidemic effect and the production of these functional metabolites or mycotoxin are influenced by many factors such as the choice of culture substrates, carbon and nitrogen source, pH value, extra nutrients, and so on. Therefore, this review focused on the effect of various culture conditions and nutrients on the functional metabolites production, hypolipidemic effect as well as citrinin concentration, and further organized the fermentation technologies used by previous studies for the promotion of hypolipidemic effect and safety.

Monascus purpureus-fermented rice inhibits tumor necrosis factor-α-induced upregulation of matrix metalloproteinase 2 and 9 in human aortic smooth muscle cells

OBJECTIVES

Inflammation is associated with atherosclerosis. Cholestin (Monascus purpureus-fermented rice) contains a naturally occurring statin, which has lipid-modulating, anti-inflammatory and antioxidative effects. This study aimed to investigate the effects of Cholestin extract on the expression of matrix metalloproteinase (MMP)-2 and MMP-9 by tumor necrosis factor (TNF)-α-treated human aortic smooth muscle cells (HASMCs).

METHODS

Zymography, reverse transcription polymerase chain reaction and immunoblot analyses were used for analysis of MMP expression of TNF-α-stimulated HASMCs. Gel shift assay was used for analysis of transcription factor nuclear factor-κB (NF-κB) activation. Intracellular reactive oxygen species (ROS) generation was also analysed.

KEY FINDINGS

The supplement of HASMCs with Cholestin extract significantly suppresses enzymatic activities of MMP-2 and MMP-9 in TNF-α-stimulated HASMCs. RT-PCR and immunoblot analyses show that Cholestin extract significantly attenuates TNF-α-induced mRNA and protein expressions of MMP-2 and MMP-9. Gel shift assays show that Cholestin treatment reduces TNF-α-activated NF-κB. Furthermore, Cholestin also attenuates intracellular ROS generation in TNF-α-treated HASMCs. The supplement with an ROS scavenger N-acetyl-cysteine (glutathione precursor) gives similar results to Cholestin.

CONCLUSIONS

Cholestin reduces TNF-α-stimulated MMP-2 and MMP-9 expression as well as downregulating NF-κB activation and intracellular ROS formation in HASMCs, supporting the notion that the natural compound Cholestin may have potential application in clinical atherosclerosis disease.

Inhibition of endothelial adhesion molecule expression by Monascus purpureus-fermented rice metabolites, monacolin K, ankaflavin, and monascin

BACKGROUND

Inflammation is an independent risk factor of cardiovascular diseases and is associated with endothelial dysfunction. Monascus purpureus-fermented rice, containing naturally occurring statins and various pigments, has lipid-modulating, anti-inflammatory and antioxidative effects.

RESULTS

The effects of monacolin K, ankaflavin and monascin, as metabolites from Monascus-fermented rice, on the expression of cell adhesion molecules (intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecular-1 (VCAM-1) and E-selectin) by tumor necrosis factor (TNF)-α-treated human aortic endothelial cells (HAECs) were investigated. Supplement of HAECs with these Monascus-fermented rice metabolites significantly suppressed cellular binding between the human monocytic cells U937 and TNF-α-stimulated HAECs. Immunoblot analysis showed that Monascus-fermented rice metabolites significantly attenuated TNF-α-induced VCAM-1 and E-selectin but not ICAM-1 protein expression. Gel shift assays showed that Monascus-fermented rice metabolites treatment reduced TNF-α-activated transcription factor nuclear factor (NF)-κB. Furthermore, Monascus-fermented rice metabolites also attenuated reactive oxygen species (ROS) generation in vitro and in TNF-α-treated HAECs. Supplement with an ROS scavenger N-acetylcysteine gave similar results as compared with Monascus-fermented rice metabolites.

CONCLUSION

Monascus-fermented rice metabolites reduced TNF-α-stimulated endothelial adhesiveness as well as downregulating intracellular ROS formation, NF-κB activation, and VCAM-1/E-selectin expression in HAECs, supporting the notion that the various metabolites from Monascus-fermented rice might have potential implications in clinical atherosclerosis disease.

Chinese red yeast rice attenuates the development of angiotensin II-induced abdominal aortic aneurysm and atherosclerosis

OBJECTIVE

Abdominal aortic aneurysm (AAA) is a chronic vascular disease characterized by medial degradation and inflammation. No medical approaches have been validated for treating AAA, and therapeutic options are limited to regular surveillance leading to surgical intervention. This study aimed to investigate whether administration of Chinese red yeast rice (Monascus purpureus; RYR) suppressed angiotensin II (AngII)-induced AAA and atherosclerosis.

METHODS AND RESULTS

Apolipoprotein E-deficient male mice fed a normal diet were administered either RYR extract (200 mg/kg/day) or vehicle by gavage for 1 week before initiating AngII infusion (1000 ng/kg/min) via subcutaneous osmotic pumps for 28 days. Red yeast rice extract administration significantly suppressed AngII-induced expansion of suprarenal diameter and area (P<.05). Furthermore, RYR extract significantly reduced atherosclerotic lesion areas in both the intima of aortic arches and cross sections of aortic roots (P<.05). These effects were associated with reductions of serum total cholesterol, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, matrix metalloproteinase (MMP) 2 and increases of serum macrophage migration inhibitory factor, but no changes in serum interleukin (IL) 1α, IL-6, monocyte chemoattractant protein 1, MMP-9 and expression of MMP-2 and MMP-9 in aortic walls.

CONCLUSIONS

This study demonstrated that RYR extract administration suppressed AngII-induced AAA and atherosclerosis associated with regulating inflammation responses independent of lipid-lowering effects. Red yeast rice may have preventive potential for patients with AAA.

Hypocholesterolemic effects of Auricularia auricula ethanol extract in ICR mice fed a cholesterol-enriched diet

The cholesterol-lowering properties of Auricularia auricula are commonly attributed to the presence of polysaccharides based on previous research. The present study was designed to investigate the effects of ethanol extract of A. auricula (AAE) on hypercholesterolemia in ICR mice. AAE contained more than 16% (g/g) polyphenolic compounds, excluding other interfering factors such as polysaccharides, water-soluble fibre and protein. Thirty-six mice were randomly assigned to three groups (n = 12). The experimental group was fed cholesterol-enriched diet (CED) with oral administration of AAE (150 mg/kg/d b.w.) for 8-week, normal control group and CED control group received either a regular diet (RD) or CED along with oral administration of equal volume distilled water. Serum lipid profiles and antioxidant status were measured in addition to fecal neutral cholesterol and bile acids. AAE showed a remarkable hypocholesterolemic effect, improving antioxidant status, decreasing the level of total cholesterol and atherosclerosis index, increasing the level of high-density lipoprotein cholesterol and fecal excretion of bile acids. No apparent effects on serum triglycerides, low-density lipoprotein cholesterol, fecal excretion of neutral cholesterol and feeding efficiency were observed among all groups. These results indicated that A. auricula functional components, which prevented hypercholesterolemia contained polyphenolic compounds, in addition to polysaccharides.

Red yeast rice stimulates osteoblast proliferation and increases alkaline phosphatase activity in MC3T3-E1 cells

Red yeast (Monascus purpureus) is used as a traditional hypocholesterolemic dietary food component in Asia due to its bioactive component, lovastatin. Recently, new evidence suggesting that the statins in red yeast enhance bone formation has been reported, but more research is still needed in order to support these claims of osteogenic effects. Therefore, in this study, we hypothesized that red yeast rice (in which red yeast is fermented) can improve osteogenic function through osteoblast cell proliferation and differentiation. We studied the effect of methanol extract of red yeast rice powder (RYRP) on osteoblast proliferation and differentiation by measuring mitochondrial enzyme activity and bone marker alkaline phosphatase (ALP) activity, respectively. Osteoblast-like MC3T3-E1 cells were cultured in various concentrations of RYRP methanol extract (0.001-1 mg/mL) during the osteoblast differentiation period (1, 5, 10, and 15 days). As measured by 3-[4,5-dimethylthiazol-2-y]-2,5-diphenyltetrazolium bromide assay, RYRP extracts stimulated cell proliferation during a 24-hour period, compared to cooked white rice powder extract. The most pronounced effect was observed at the concentration range between 0.075 and 0.1 mg/mL. This RYRP stimulatory effect for cell proliferation was observed during the whole osteogenic period. Cellular (synthesized) ALP activity was increased at a RYRP extract concentration of 0.075 mg/mL during 15 days of culture, but the medium (secreted) ALP activity did not show any significant change. This cellular ALP activity stimulation by RYRP extract was confirmed by the staining of ALP activity on cell matrix layers for matrix calcification. The results imply that RYRP extract may increase osteogenic effect by stimulating cell proliferation and ALP activity in osteoblastic cells.

Mycotoxin citrinin induced cell cycle G2/M arrest and numerical chromosomal aberration associated with disruption of microtubule formation in human cells

As a nephrotoxic mycotoxin, citrinin (CTN) contaminates various foodstuffs and animal feed commodities. In the present study, the effects of CTN on cell cycle arrest and microtubule formation were investigated by applying human embryonic kidney (HEK293) cells as a model. Exposure of HEK293 cells to CTN resulted in an arrest of cell cycle G2/M in a concentration-dependent increase. Administrating CTN elevated the expression levels of p53 and p21 proteins, yet attenuated the signals of phosphorylated cell division cycle 2 (cdc2). Furthermore, treating HEK293 with CTN increased both the value of mitotic index and the population of cells recognized by antibody mitotic protein monoclonal 2, suggesting that arrest of CTN-induced cell cycle occurred mainly during the mitotic phase. With the assistance of immunocytostaining of α-tubulin, CTN was found to disrupt the stable microtubule skeleton during the interphase of cell cycle and also interfere with the mitotic spindle integrity during mitosis. Additionally, for either in vivo or in vitro assays, CTN effectively inhibited tubulin polymerization in a concentration-dependent manner. When human peripheral blood mononuclear cells were exposed to CTN, the percentage of cells with numerical chromosome changes was increased by 4.3-fold over that of vehicle-treated group. Results of this study suggest that CTN-activated G2/M arrest primarily arises from the inhibition of tubulin polymerization and associated mitotic spindle formation. Additionally, disruption of microtubule organization by CTN also contributes to the induction of numerical chromosome aberration in human cells.

Red mold rice promotes neuroprotective sAPPalpha secretion instead of Alzheimer's risk factors and amyloid beta expression in hyperlipidemic Abeta40-infused rats

Amyloid beta (Abeta) peptide is closely related to the onset of Alzheimer's disease (AD). A high-cholesterol or high-energy diet was demonstrated to stimulate Abeta formation and deposition in the amyloid precursor protein (APP) pathway and, oppositely, downregulate the secretion of the neuroprotective soluble APP alpha-fragment (sAPPalpha). Monascus-fermented red mold rice (RMR) including multiple cholesterol-lowering agents, antioxidants, and anti-inflammatory agents has been proven to ameliorate Abeta40 infusion-induced memory deficit in our previous study. In this study, the ethanol extract of RMR (RE) and natural RMR were respectively tested for their effect on the mediation of the proteolytic process of APP in cholesterol-treated human neuroblastoma IMR32 cell, as well as their effect on memory and learning ability and the expression of AD risk factors in intracerebroventricular Abeta40-infused hyperlipidemic rats. In the results, RE suppressed cholesterol-raised beta-secretase activity and further resulted in the increase of sAPPalpha secretion in the IMR32 cell. In the animal test, RMR potently reversed the memory deficit in the water maze and passive avoidance tasks. RMR administration could prevent against Abeta40 infusion plus the great damage caused by a high energy diet in hippocampus and cortex involved in the raise of thiobarbituric acid reactive substances and reactive oxygen species. The neuroprotection provided by RMR downregulates Abeta40 formation and deposition by suppressing the cholesterol-raised beta-secretase activity and apolipoprotein E expression, as well as mediates the proteolytic process of APP toward neuroprotective sAPPalpha secretion in hippocampus.

Activation of JNK and PAK2 is essential for citrinin-induced apoptosis in a human osteoblast cell line

The mycotoxin citrinin (CTN), a natural contaminant in foodstuffs and animal feeds, exerts cytotoxic and genotoxic effects on various mammalian cells. CTN causes cell injury, including apoptosis. Previous studies by our group showed that CTN triggers apoptosis in mouse embryonic stem cells, as well as embryonic developmental injury. Here, we investigated the precise mechanisms governing this apoptotic effect in osteoblasts. CTN induced apoptotic biochemical changes in a human osteoblast cell line, including activation of c-Jun N-terminal kinase (JNK), loss of mitochondrial membrane potential, and caspase-3 and p21-activated protein kinase 2 (PAK2) activation. Experiments using a JNK-specific inhibitor, SP600125, and antisense oligonucleotides against JNK reduced CTN-induced activation of both JNK and caspase-3 in osteoblasts, indicating that JNK is required for caspase activation in this apoptotic pathway. Experiments using caspase-3 inhibitors and antisense oligonucleotides against PAK2 revealed that active caspase-3 is essential for PAK2 activation. Moreover, both caspase-3 and PAK2 require activation for CTN-induced apoptosis of osteoblasts. Interestingly, CTN stimulates two-stage activation of JNK in human osteoblasts. Early-stage JNK activation is solely ROS-dependent, whereas late-stage activation is dependent on ROS-mediated caspase activity, and regulated by caspase-induced activation of PAK2. On the basis of these results, we propose a signaling cascade model for CTN-induced apoptosis in human osteoblasts involving ROS, JNK, caspases, and PAK2.

Red yeast rice increases excretion of bile acids in hamsters

OBJECTIVE

To investigate the hypocholesterolemic activity of red yeast rice (RYR) and its underlying mechanism.

METHODS

Three groups of hamsters were fed either the control diet or one of the two experimental diets containing by weight 0.1% RYR (0.1RYR) or 0.3% RYR (0.3RYR). Blood (0.5 mL) was collected from the retro-orbital sinus into a heparinized capillary tube at the end of week 0, 3, and 6. Plasma lipoproteins were measured using enzymatic kits, while fecal neutral and acidic sterols were quantified using a gas-liquid chromatography.

RESULTS

Plasma total cholesterol was reduced by 12% in 0.1RYR group and by 18% in 0.3RYR group compared with the control value. Similarly, plasma triacylglycerol was decreased by 11% in 0.1RYR group and by 24% in 0.3RYR group. Western blotting analysis demonstrated that RYR had no effect on sterol regulatory element binding protein 2, liver X receptor, 3-hydroxy-3-methylglutary-CoA reductase, LDL receptor, and cholesterol-7alpha-hydroxylase. HPLC analysis confirmed that RYR contained 0.88% monacolin K. It was recently found that RYR supplementation increased excretion of fecal acidic sterols by 3-4 folds compared with the control value.

CONCLUSION

Hypocholesterolemic activity of RYR is mediated at least partially by enhancement of acidic sterol excretion.

Inhibition of citrinin-induced apoptotic biochemical signaling in human hepatoma G2 cells by resveratrol

The mycotoxin citrinin (CTN), a natural contaminant in foodstuffs and animal feeds, exerts cytotoxic and genotoxic effects on various mammalian cells. CTN causes cell injury, including apoptosis, but its precise regulatory mechanisms of action are currently unclear. Resveratrol, a member of the phytoalexin family found in grapes and other dietary plants, possesses antioxidant and anti-tumor properties. In the present study, we examined the effects of resveratrol on apoptotic biochemical events in Hep G2 cells induced by CTN. Resveratrol inhibited CTN-induced ROS generation, activation of JNK, loss of mitochondrial membrane potential (MMP), as well as activation of caspase-9, caspase-3 and PAK2. Moreover, resveratrol and the ROS scavengers, NAC and α-tocopherol, abolished CTN-stimulated intracellular oxidative stress and apoptosis. Active JNK was required for CTN-induced mitochondria-dependent apoptotic biochemical changes, including loss of MMP, and activation of caspases and PAK2. Activation of PAK2 was essential for apoptosis triggered by CTN. These results collectively demonstrate that CTN stimulates ROS generation and JNK activation for mitochondria-dependent apoptotic signaling in Hep G2 cells, and these apoptotic biochemical events are blocked by pretreatment with resveratrol, which exerts antioxidant effects.

Efficacy and safety of Monascus purpureus Went rice in children and young adults with secondary hyperlipidemia: a preliminary report

BACKGROUNDS/AIMS

Nephrotic dyslipidemia is a risk factor for development of systemic atherosclerosis; also it may aggravate glomerulosclerosis and enhance progression of glomerular disease. We aimed to assess the efficacy and safety of Monascus purpureus Went rice vs. fluvastatin therapy in the management of nephrotic dyslipidemia.

METHODS

Seventy-two patients with idiopathic persistent nephrotic syndrome with secondary dyslipidemia were included. They were randomly allocated into 3 - age and sex - matched groups. The first group comprised of 20 cases and were given Monascus purpureus Went rice, second group comprised 30 cases were given fluvastatin. The remaining 22 received no anti-dyslipidemic therapy and constituted a control group. All of these patients were subjected to thorough laboratory investigations including renal function tests, lipogram and neurological assessment.

RESULTS

Our results showed that both fluvastatin and Monascus purpureus Went rice were well-tolerated with no significant side effects. Both of them significantly reduced cholesterol after 6 months and 1 year. In comparison to baseline values, fluvastatin achieved a significant and progressive reduction of serum cholesterol by 35%, 38% and 42% at 3 months, 6 months and after 1 year respectively (p<0.001). Similar reductions were observed in the Monascus purpureus Went rice group. After one year we observed that serum cholesterol was significantly lower in statin and Monascus purpureus Went rice groups compared to the control group.

CONCLUSION

Monascus purpureus Went rice is safe, effective cholesterol lowering agent for nephrotic dyslipidemia both in adults and children.

Cholesterol-lowering nutraceuticals and functional foods

Epidemiological studies have demonstrated that elevated levels of plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) are the major risk factors for coronary heart disease (CHD), whereas high concentrations of plasma high-density lipoprotein cholesterol (HDL-C) and a low ratio of TC to HDL-C are protective against CHD. A relationship between plasma TC and the risk of CHD is well established at concentrations above 240 mg/dL. In addition to the use of three main classes of cholesterol-lowering medications, including HMG-CoA reductase inhibitors, anion-exchange resins, and fibrates, a nutritionally balanced diet that reduces saturated fat and cholesterol intake has traditionally been the first goal of dietary therapy in lowering plasma TC. In recent years, nutraceuticals and functional foods have attracted much interest as possible alternative therapies for lowering plasma TC, especially for hypercholesterolemia patients, whose blood cholesterol level is marginally high (200-240 mg/dL) but not high enough to warrant the prescription of cholesterol-lowering medications. This review summarizes the findings of recent studies on the production, application, efficacy, and mechanisms of popular cholesterol-lowering nutraceuticals and functional foods.

Citrinin induces apoptosis in mouse embryonic stem cells

The mycotoxin citrinin (CTN) is a natural contaminant in foodstuffs and animal feeds, and exerts cytotoxic and genotoxic effects on various mammalian cells. CTN causes cell injury, including apoptosis. However, its precise regulatory mechanisms of action, particularly in stem cells and embryos, are currently unclear. Recent studies show that CTN has cytotoxic effects on mouse embryonic stem cells and blastocysts, and is associated with defects in their subsequent development, both in vitro and in vivo. Experiments with the embryonic stem cell line, ESC-B5, disclose that CTN induces apoptosis via several mechanisms, including ROS generation, increased cytoplasmic free calcium levels, intracellular nitric oxide production, enhanced Bax/Bcl-2 ratio, loss of mitochondrial membrane potential, cytochrome c release, activation of caspase-9 and caspase-3, and p21-activated protein kinase 2 and c-Jun N-terminal protein kinase activation. Additional studies show that CTN promotes cell death via inactivation of the HSP90/multi-chaperone complex and subsequent degradation of Ras and Raf-1, further inhibiting anti-apoptotic processes such as the Ras-->ERK signal transduction pathway. On the basis of these findings, we propose a model for CTN-induced cell injury signalling cascades in embryonic stem cells and blastocysts.

Monascus purpureus Went rice in nephrotic hyperlipidemia

BACKGROUND

Nephrotic dyslipidemia is a risk factor for the development of systemic atherosclerosis; and may aggravate glomerulosclerosis and enhance progression of glomerular disease. We aimed to assess the efficacy and safety of Monascus purpureus Went rice vs. fluvastatin therapy in the management of nephrotic dyslipidemia.

MATERIALS AND METHODS

Seventy-two patients with persistent idiopathic nephrotic syndrome (NS) with secondary dyslipidemia were included. They were randomly allocated into three age and sex-matched groups. The first group comprised 20 cases and were given M. purpureus Went rice in a dose of 600 mg twice/day for 1 month then once daily, the second group comprised 30 cases were given fluvastatin in a daily dose of 20 mg. The remaining 22 received no antidyslipidemic therapy and constituted a control group. All of these patients were subjected to thorough laboratory investigations including renal function tests and lipogram. Moreover, the neuromuscular status was evaluated with electromyography and nerve conduction velocity.

RESULTS

Our results showed that both fluvstatin and M. purpureus Went rice were well tolerated with no evidence of significant side effects including neuromuscular functions. Both of them significantly reduced cholesterol after 6 months and 1 year.

CONCLUSION

Monascus purpureus Went rice is safe, effective, and economic treatment strategy for nephrotic dyslipidemia.

Cholestin (Monascus purpureus rice) inhibits homocysteine-induced reactive oxygen species generation, nuclear factor-κB activation, and vascular cell adhesion molecule-1 expression in human aortic endothelial cells

Hyperhomocysteinemia is associated with dysfunction and an independent risk factor of cardiovascular diseases. Cholestin (Monascus purpureus-fermented rice), contains a naturally-occurring statin, which has lipid-modulating and anti-inflammatory effects. We investigated the effects of Cholestin extract on the expression of vascular cell adhesion molecule-1 (VCAM-1) by homocysteine (HCY)-treated human aortic endothelial cells (HAECs). Supplement of HAECs with Cholestin extract significantly suppressed cellular binding between the human monocytic cells U937 and HCY-stimulated HAECs. Quantitative PCR and immunoblot analysis showed that Cholestin extract significantly attenuated HCY-induced expression of VCAM-1 mRNA and protein, respectively. Gel shift assays showed that Cholestin treatment reduced HCY-activated transcription factor nuclear factor-kappaB (NF-kappaB). Furthermore, Cholestin also attenuated reactive oxygen species (ROS) generation in vitro and in HCY-treated HAECs. Supplement with statins including simvastatin and parastatin gave similar results as compared with Cholestin. In conclusion, Cholestin reduces HCY-stimulated endothelial adhesiveness as well as downregulating intracellular ROS formation, NF-kappaB activation, and VCAM-1 expression in HAECs, supporting the notion that the natural compound Cholestin may have potential implications in clinical atherosclerosis disease.