Cyanidin-3-O-β-glucoside upregulates hepatic cholesterol 7α-hydroxylase expression and reduces hypercholesterolemia in mice

Dan-shen Yin promotes bile acid metabolism and excretion to prevent atherosclerosis via activating FXR/BSEP signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Dan-shen Yin (DSY), a traditional prescription, has been demonstrated to be effective in decreasing hyperlipidemia and preventing atherosclerosis (AS), but its mechanism remains unknown. We hypothesized that DSY activates farnesoid X receptor (FXR) to promote bile acid metabolism and excretion, thereby alleviating AS.

AIM OF THE STUDY

This study was designed to explore whether DSY reduces liver lipid accumulation and prevents AS by activating FXR and increasing cholesterol metabolism and bile acid excretion.

MATERIALS AND METHODS

The comprehensive chemical characterization of DSY was analyzed by UHPLC-MS/MS. The AS models of ApoE-/- mice and SD rats was established by high-fat diet and high-fat diet combined with intraperitoneal injection of vitamin D3, respectively. The aortic plaque and pathological changes were used to evaluate AS. Lipid levels, H&E staining and oil red O staining were used to evaluate liver lipid accumulation. The cholesterol metabolism and bile acid excretion were evaluated by enzyme-linked immunosorbent assay, UPLC-QQQ/MS. In vitro, the lipid and FXR/bile salt export pump (BSEP) levels were evaluated by oil red O staining, real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting.

RESULTS

A total of 36 ingredients in DSY were identified by UPLC-MS/MS analysis. In vivo, high-dose DSY significantly inhibited aortic intimal thickening, improved arrangement disorder, tortuosity, and rupture of elastic fibers, decreased lipid levels, and reduced the number of fat vacuoles and lipid droplets in liver tissue in SD rats and ApoE-/- mice. Further studies found that high-dose DSY significantly reduced liver lipid and total bile acids levels, increased liver ursodeoxycholic acid (UDCA) and other non-conjugated bile acids levels, increased fecal total cholesterol (TC) levels, and augmented FXR, BSEP, cholesterol 7-alpha hydroxylase (CYP7A1), ATP binding cassette subfamily G5/G8 (ABCG5/8) expression levels, while decreasing ASBT expression levels. In vitro studies showed that DSY significantly reduced TC and TG levels, as well as lipid droplets, while also increasing the expression of ABCG5/8, FXR, and BSEP in both HepG2 and Nr1h4 knockdown HepG2 cells.

CONCLUSION

This study demonstrated that DSY promotes bile acid metabolism and excretion to prevent AS by activating FXR. For the prevent of AS and drug discovery provided experimental basis.

Beneficial effects of flavonoids on animal models of atherosclerosis: A systematic review and meta-analysis

Atherosclerosis is the main cause of cardiovascular diseases that seriously endanger human health. The existing treatment drugs are effective, but they have some side effects. Accumulating evidence suggests that flavonoids have attracted wide attention due to their multiple cardioprotective effects and fewer side effects. PubMed, Web of Science database, Embase, and Cochrane Library were searched for studies evaluating the effects of flavonoids against atherosclerosis. 119 studies published from August 1954 to April 2023 were included. Random-effects models were performed for synthesis. Compared with the control group, flavonoids significantly reduced longitudinal and cross-sectional plaque area. The findings indicated that flavonoids significantly reduced the concentrations of serum TC, TG, and LDL-C and increased serum HDL-C concentrations. Besides, flavonoids reduced the levels of circulating pro-inflammatory factors, including TNF-α, IL-1β, and IL-6, and increased the serum IL-10 level. This study provides evidence for the potential cardiovascular benefits of flavonoids.

Recent advances in nuclear receptors-mediated health benefits of blueberry

BACKGROUND

Blueberry is rich in bioactive substances and has anti-oxidant, anti-inflammatory, anti-obesity, anti-cancer, neuroprotective, and other activities. Blueberry has been shown to treat diseases by mediating the transcription of nuclear receptors. However, evidence for nuclear receptor-mediated health benefits of blueberry has not been systematically reviewed.

PURPOSE

This review aims to summarize the nuclear receptor-mediated health benefits of blueberry.

METHODS

This study reviews all relevant literature published in NCBI PubMed, Scopus, Web of Science, and Google Scholar by January 2022. The relevant literature was extracted from the databases with the following keyword combinations: "biological activities" OR "nuclear receptors" OR "phytochemicals" AND "blueberry" OR "Vaccinium corymbosum" as well as free-text words.

RESULTS

In vivo and in vitro experimental results and clinical evidence have demonstrated that blueberry has health-promoting effects. Supplementing blueberry is beneficial to the treatment of cancer, the alleviation of metabolic syndrome, and liver protection. Blueberry can regulate the transcription of PPARs, ERs, AR, GR, MR, LXRs, and FXR and mediate the expressions of Akt, CYP 1Al, p53, and Bcl-2.

CONCLUSION

Blueberry can be targeted to treat various diseases by mediating the transcription of nuclear receptors. Nevertheless, further human research is needed.

Natural Flavonoids Derived From Fruits Are Potential Agents Against Atherosclerosis

Atherosclerosis, as a chronic inflammatory response, is one of the main causes of cardiovascular diseases. Atherosclerosis is induced by endothelial cell dysfunction, migration and proliferation of smooth muscle cells, accumulation of foam cells and inflammatory response, resulting in plaque accumulation, narrowing and hardening of the artery wall, and ultimately leading to myocardial infarction or sudden death and other serious consequences. Flavonoid is a kind of natural polyphenol compound widely existing in fruits with various structures, mainly including flavonols, flavones, flavanones, flavanols, anthocyanins, isoflavones, and chalcone, etc. Because of its potential health benefits, it is now used in supplements, cosmetics and medicines, and researchers are increasingly paying attention to its role in atherosclerosis. In this paper, we will focus on several important nodes in the development of atherosclerotic disease, including endothelial cell dysfunction, smooth muscle cell migration and proliferation, foam cell accumulation and inflammatory response. At the same time, through the classification of flavonoids from fruits, the role and potential mechanism of flavonoids in atherosclerosis were reviewed, providing a certain direction for the development of fruit flavonoids in the treatment of atherosclerosis drugs.

Anthocyanins, Anthocyanin-Rich Berries, and Cardiovascular Risks: Systematic Review and Meta-Analysis of 44 Randomized Controlled Trials and 15 Prospective Cohort Studies

Objective: The associations between intake of anthocyanins and anthocyanin-rich berries and cardiovascular risks remained to be established. We aimed to quantitatively summarize the effects of purified anthocyanins and anthocyanin-rich berries on major surrogate markers of cardiovascular diseases (CVDs) and the longitudinal associations between dietary anthocyanins and CVD events.

Methods: Meta-analysis of randomized controlled trials (RCTs) and prospective cohort studies.

Results: We included 44 eligible RCTs and 15 prospective cohort studies in this study. Pooled analysis of RCTs showed that purified anthocyanin supplementation could significantly reduce blood LDL cholesterol (weighted mean difference (WMD): −5.43 mg/dL, 95% CI: −8.96, −1.90 mg/dL; p = 0.003) and triglyceride (WMD: −6.18 mg/dL, 95% CI: −11.67, −0.69 mg/dL; p = 0.027) while increase HDL cholesterol (WMD: 11.49 mg/dL, 95% CI: 7.43, 15.55 mg/dL; p < 0.001) concentrations. Purified anthocyanins also markedly decreased circulating tumor necrosis factor alpha (WMD: −1.62 pg/mL, 95% CI: −2.76, −0.48 pg/mL; p = 0.005) and C-reactive protein (WMD: −0.028 mg/dL, 95% CI: −0.050, −0.005 mg/dL; p = 0.014). Besides, administration of anthocyanin-rich berries could significantly lower blood total cholesterol (WMD: −4.48 mg/dL, 95% CI: −8.94, −0.02 mg/dL; p = 0.049) and C-reactive protein (WMD: −0.046 mg/dL, 95% CI: −0.070, −0.022 mg/dL; p < 0.001). Neither purified anthocyanins nor anthocyanin-rich berries could cause any substantial improvements in BMI, blood pressure, or flow-mediated dilation. In addition, meta-analysis of prospective cohort studies suggested that high dietary anthocyanins were related to lower risk of coronary heart disease (CHD) (relative risk (RR): 0.83, 95% CI: 0.72, 0.95; p = 0.009), total CVD incidence (RR: 0.73, 95% CI: 0.55, 0.97; p = 0.030), and total CVD deaths (RR: 0.91, 95% CI: 0.87, 0.96; p < 0.001).

Conclusion: Habitual intake of anthocyanins and anthocyanin-rich berries could protect against CVDs possibly via improving blood lipid profiles and decreasing circulating proinflammatory cytokines.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42020208782.

Cholesterol-lowering activity of protocatechuic acid is mediated by increasing the excretion of bile acids and modulating gut microbiota and producing short-chain fatty acids

The present study aimed to investigate the effects of protocatechuic acid (PCA) on plasma lipid profiles and associated mechanisms with a focus on reshaping gut microbiota. Twenty-four male hamsters were randomly divided into three groups receiving a high-cholesterol diet (HCD) and two HCD diets containing 0.5% (PL) and 1% (PH) PCA, respectively. Feeding PL and PH diets for six weeks significantly reduced plasma total cholesterol by 18% and 24%, respectively. PL and PH diets also significantly lowered plasma non-HDL cholesterol by 37% and 44%, respectively. This was accompanied by an increase in fecal short-chain fatty acids (SCFAs) and fecal bile acids with up-regulation on gene of cholesterol 7α-hydroxylase and down-regulation of 3-hydroxy-3-methylglutaryl-CoA reductase in the liver. Dietary PCA supplementation decreased hepatic lipid accumulation, whereas it increased fecal excretion of lipids. The 16S rRNA analysis found that dietary PCA significantly reduced the ratio of Firmicutes to Bacteroidetes and increased the relative abundance of Bacteroidales S24-7, whereas it reduced the abundance of Lactobacillaceae. It was concluded that dietary PCA favorably modulated plasma lipid profiles and prevented the accumulation of hepatic cholesterol and lipid disposition. Such effect was mediated at least partially by increasing gut production of SCFAs and fecal excretion of bile acids via modulating the gut microbiome.

Bioactivity of Dietary Polyphenols: The Role in LDL-C Lowering

Cardiovascular diseases are the leading causes of the death around the world. An elevation of the low-density lipoprotein cholesterol (LDL-C) level is one of the most important risk factors for cardiovascular diseases. To achieve optimal plasma LDL-C levels, clinal therapies were investigated which targeted different metabolism pathways. However, some therapies also caused various adverse effects. Thus, there is a need for new treatment options and/or combination therapies to inhibit the LDL-C level. Dietary polyphenols have received much attention in the prevention of cardiovascular diseases due to their potential LDL-C lowering effects. However, the effectiveness and potential mechanisms of polyphenols in lowering LDL-C is not comprehensively summarized. This review focused on dietary polyphenols that could reduce LDL-C and their mechanisms of action. This review also discussed the limitations and suggestions regarding previous studies.

Phytochemicals: Targeting Mitophagy to Treat Metabolic Disorders

Metabolic disorders include metabolic syndrome, obesity, type 2 diabetes mellitus, non-alcoholic fatty liver disease and cardiovascular diseases. Due to unhealthy lifestyles such as high-calorie diet, sedentary and physical inactivity, the prevalence of metabolic disorders poses a huge challenge to global human health, which is the leading cause of global human death. Mitochondrion is the major site of adenosine triphosphate synthesis, fatty acid β-oxidation and ROS production. Accumulating evidence suggests that mitochondrial dysfunction-related oxidative stress and inflammation is involved in the development of metabolic disorders. Mitophagy, a catabolic process, selectively degrades damaged or superfluous mitochondria to reverse mitochondrial dysfunction and preserve mitochondrial function. It is considered to be one of the major mechanisms responsible for mitochondrial quality control. Growing evidence shows that mitophagy can prevent and treat metabolic disorders through suppressing mitochondrial dysfunction-induced oxidative stress and inflammation. In the past decade, in order to expand the range of pharmaceutical options, more and more phytochemicals have been proven to have therapeutic effects on metabolic disorders. Many of these phytochemicals have been proved to activate mitophagy to ameliorate metabolic disorders. Given the ongoing epidemic of metabolic disorders, it is of great significance to explore the contribution and underlying mechanisms of mitophagy in metabolic disorders, and to understand the effects and molecular mechanisms of phytochemicals on the treatment of metabolic disorders. Here, we investigate the mechanism of mitochondrial dysfunction in metabolic disorders and discuss the potential of targeting mitophagy with phytochemicals for the treatment of metabolic disorders, with a view to providing a direction for finding phytochemicals that target mitophagy to prevent or treat metabolic disorders.

Hepatic cholesterol transport and its role in non-alcoholic fatty liver disease and atherosclerosis

Non-alcoholic fatty liver disease (NAFLD) is a quickly emerging global health problem representing the most common chronic liver disease in the world. Atherosclerotic cardiovascular disease represents the leading cause of mortality in NAFLD patients. Cholesterol metabolism has a crucial role in the pathogenesis of both NAFLD and atherosclerosis. The liver is the major organ for cholesterol metabolism. Abnormal hepatic cholesterol metabolism not only leads to NAFLD but also drives the development of atherosclerotic dyslipidemia. The cholesterol level in hepatocytes reflects the dynamic balance between endogenous synthesis, uptake, esterification, and export, a process in which cholesterol is converted to neutral cholesteryl esters either for storage in cytosolic lipid droplets or for secretion as a major constituent of plasma lipoproteins, including very-low-density lipoproteins, chylomicrons, high-density lipoproteins, and low-density lipoproteins. In this review, we describe decades of research aimed at identifying key molecules and cellular players involved in each main aspect of hepatic cholesterol metabolism. Furthermore, we summarize the recent advances regarding the biological processes of hepatic cholesterol transport and its role in NAFLD and atherosclerosis.

Circulating bile acids as a link between the gut microbiota and cardiovascular health: impact of prebiotics, probiotics and polyphenol-rich foods

Beneficial effects of probiotic, prebiotic and polyphenol-rich interventions on fasting lipid profiles have been reported, with changes in the gut microbiota composition believed to play an important role in lipid regulation. Primary bile acids, which are involved in the digestion of fats and cholesterol metabolism, can be converted by the gut microbiota to secondary bile acids, some species of which are less well reabsorbed and consequently may be excreted in the stool. This can lead to increased hepatic bile acid neo-synthesis, resulting in a net loss of circulating low-density lipoprotein. Bile acids may therefore provide a link between the gut microbiota and cardiovascular health. This narrative review presents an overview of bile acid metabolism and the role of probiotics, prebiotics and polyphenol-rich foods in modulating circulating cardiovascular disease (CVD) risk markers and bile acids. Although findings from human studies are inconsistent, there is growing evidence for associations between these dietary components and improved lipid CVD risk markers, attributed to modulation of the gut microbiota and bile acid metabolism. These include increased bile acid neo-synthesis, due to bile sequestering action, bile salt metabolising activity and effects of short-chain fatty acids generated through bacterial fermentation of fibres. Animal studies have demonstrated effects on the FXR/FGF-15 axis and hepatic genes involved in bile acid synthesis (CYP7A1) and cholesterol synthesis (SREBP and HMGR). Further human studies are needed to determine the relationship between diet and bile acid metabolism and whether circulating bile acids can be utilised as a potential CVD risk biomarker.

Protective Effects of Morus nigra and Its Phytochemicals against Hepatotoxicity: A Review of Preclinical Studies

BACKGROUND

Our liver has a variety of vital functions including removing poisons, storing energy, immunological roles, and secretory and excretory functions. It may face some kinds of diseases caused by viruses, hepatotoxic chemicals, drugs, alcohol, and inherited disorders. Oxidative stress and inflammation are in the core of mechanisms of liver damages induced by viruses or chemical agents.

SUMMARY

Morus nigra (M. nigra), generally known as black mulberry, exhibited wide-spectrum pharmacological effects including antidiabetic, antinociceptive, anticancer, and hepatoprotective activities. Different parts of this plant particularly the fruit and leaf have shown beneficial effects on hepatocytes in cell culture and animal models of liver damages induced by chemicals (e.g., CCl4), drugs (e.g., paracetamol), diet (e.g., high fat), diabetes, etc. The beneficial effects of M. nigra on the liver are attributed to the presence of considerable amounts of phenolic compounds such as anthocyanins, flavonols, and phenolic acids. The present review is aimed to focus on the hepatoprotective activities of M. nigra and its phytochemicals and the mechanisms responsible for these activities. Key Messages: The evidence reviewed in this study can help design clinical trials on M. nigra in patients with liver disorders and develop a hepatoprotective herbal medicine.

Anthocyanins: A Comprehensive Review of Their Chemical Properties and Health Effects on Cardiovascular and Neurodegenerative Diseases

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables. Dietary sources of anthocyanins include red and purple berries, grapes, apples, plums, cabbage, or foods containing high levels of natural colorants. Cyanidin, delphinidin, malvidin, peonidin, petunidin, and pelargonidin are the six common anthocyanidins. Following consumption, anthocyanin, absorption occurs along the gastrointestinal tract, the distal lower bowel being the place where most of the absorption and metabolism occurs. In the intestine, anthocyanins first undergo extensive microbial catabolism followed by absorption and human phase II metabolism. This produces hybrid microbial-human metabolites which are absorbed and subsequently increase the bioavailability of anthocyanins. Health benefits of anthocyanins have been widely described, especially in the prevention of diseases associated with oxidative stress, such as cardiovascular and neurodegenerative diseases. Furthermore, recent evidence suggests that health-promoting effects attributed to anthocyanins may also be related to modulation of gut microbiota. In this paper we attempt to provide a comprehensive view of the state-of-the-art literature on anthocyanins, summarizing recent findings on their chemistry, biosynthesis, nutritional value and on their effects on human health.

Protective Effects of Black Raspberry (Rubus occidentalis) Extract against Hypercholesterolemia and Hepatic Inflammation in Rats Fed High-Fat and High-Choline Diets

Choline is converted to trimethylamine by gut microbiota and further oxidized to trimethylamine-N-oxide (TMAO) by hepatic flavin monooxygenases. Positive correlation between TMAO and chronic diseases has been reported. Polyphenols in black raspberry (BR), especially anthocyanins, possess various biological activities. The objective of this study was to determine the effects of BR extract on the level of choline-derived metabolites, serum lipid profile, and inflammation markers in rats fed high-fat and high-choline diets. Forty female Sprague-Dawley (SD) rats were randomly divided into four groups and fed for 8 weeks as follows: CON (AIN-93G diet), HF (high-fat diet), HFC (HF + 1.5% choline water), and HFCB (HFC + 0.6% BR extract). Serum levels of TMAO, total cholesterol, and low-density lipoprotein (LDL)-cholesterol and cecal trimethylamine (TMA) level were significantly higher in the HFC than in the HFCB. BR extract decreased mRNA expression of pro-inflammatory genes including nuclear factor-κB (NF-κB), interleukin (IL)-1β, IL-6, and cyclooxygenase-2 (COX-2), and protein expression of NF-κB and COX-2 in liver tissue. These results suggest that consistent intake of BR extract might alleviate hypercholesterolemia and hepatic inflammation induced by excessive choline with a high-fat diet via lowering elevated levels of cecal TMA and serum TMAO in rats.

LC-Q-TOF-MS Characterization of Polyphenols from White Bayberry Fruit and Its Antidiabetic Effect in KK-Ay Mice

The present study is to investigate the polyphenolic composition and in vivo antidiabetic effect of white-fleshed Chinese bayberry cultivar "Shui Jing". By liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS), 38 polyphenols were identified in the Shui Jing fruit extract (SJE), where proanthocyanidins (PAs), including epigallocatechin gallate (EGCG), as well as flavonols, including myricitrin and quercetrin, were the predominant ingredients. After a 5-week experiment, the SJE (200 mg/kg bodyweight) significantly reduced fasting blood glucose, elevated glucose tolerance, and insulin sensitivity in diabetic KK-A^y mice. It markedly attenuated bodyweight gain and decreased glycolipid metabolism-related markers including insulin, leptin, glucagon, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) and alanine aminotransferase (ALT) levels in mice. Liver weight and hepatic lipid accumulation were also significantly reduced by the SJE. Gene expressions of insulin 1 (INS1) and glycogen synthase kinase 3 β (GSK3b) were markedly inhibited while the hepatic phosphorylation of AMPKα was significantly increased in the liver of SJE-treated mice, indicating that the SJE may exert an antidiabetic effect through an AMPK-dependent pathway. In conclusion, white bayberry rich in PAs and flavonols may have great potential in the regulation of diabetes mellitus.

Beneficial effects of lingonberry (Vaccinium vitis-idaea L.) supplementation on metabolic and inflammatory adverse effects induced by high-fat diet in a mouse model of obesity

Obesity is a constantly increasing health problem worldwide. It is associated with a systemic low-grade inflammation, which contributes to the development of metabolic disorders and comorbidities such as type 2 diabetes. Diet has an important role in the prevention of obesity and its adverse health effects; as a part of healthy diet, polyphenol-rich berries, such as lingonberry (Vaccinium vitis-idaea L.) have been proposed to have health-promoting effects. In the present study, we investigated the effects of lingonberry supplementation on high-fat diet induced metabolic and inflammatory changes in a mouse model of obesity. Thirty male C57BL/6N mice were divided into three groups (n = 10/group) to receive low-fat (LF), high-fat (HF) and lingonberry-supplemented high-fat (HF+LGB) diet for six weeks. Low-fat and high-fat diet contained 10% and 46% of energy from fat, respectively. Lingonberry supplementation prevented the high-fat diet induced adverse changes in blood cholesterol and glucose levels and had a moderate effect on the weight and visceral fat gain, which were 26% and 25% lower, respectively, in the lingonberry group than in the high-fat diet control group. Interestingly, lingonberry supplementation also restrained the high-fat diet induced increases in the circulating levels of the proinflammatory adipocytokine leptin (by 36%) and the inflammatory acute phase reactant serum amyloid A (SAA; by 85%). Similar beneficial effects were discovered in the hepatic expression of the inflammatory factors CXCL-14, S100A10 and SAA by lingonberry supplementation. In conclusion, the present results indicate that lingonberry supplementation significantly prevents high-fat diet induced metabolic and inflammatory changes in a murine model of obesity. The results encourage evaluation of lingonberries as a part of healthy diet against obesity and its comorbidities.

Polyphenol Effects on Cholesterol Metabolism via Bile Acid Biosynthesis, CYP7A1: A Review

Atherosclerosis, the main contributor to coronary heart disease, is characterised by an accumulation of lipids such as cholesterol in the arterial wall. Reverse cholesterol transport (RCT) reduces cholesterol via its conversion into bile acids (BAs). During RCT in non-hepatic peripheral tissues, cholesterol is transferred to high-density lipoprotein (HDL) particles and returned to the liver for conversion into BAs predominantly via the rate-limiting enzyme, cholesterol 7 α-hydroxylase (CYP7A1). Numerous reports have described that polyphenol induced increases in BA excretion and corresponding reductions in total and LDL cholesterol in animal and in-vitro studies, but the process whereby this occurs has not been extensively reviewed. There are three main mechanisms by which BA excretion can be augmented: (1) increased expression of CYP7A1; (2) reduced expression of intestinal BA transporters; and (3) changes in the gut microbiota. Here we summarise the BA metabolic pathways focusing on CYP7A1, how its gene is regulated via transcription factors, diurnal rhythms, and microRNAs. Importantly, we will address the following questions: (1) Can polyphenols enhance BA secretion by modulating the CYP7A1 biosynthetic pathway? (2) Can polyphenols alter the BA pool via changes in the gut microbiota? (3) Which polyphenols are the most promising candidates for future research? We conclude that while in rodents some polyphenols induce CYP7A1 expression predominantly by the LXRα pathway, in human cells, this may occur through FXR, NF-KB, and ERK signalling. Additionally, gut microbiota is important for the de-conjugation and excretion of BAs. Puerarin, resveratrol, and quercetin are promising candidates for further research in this area.

An Exploration of the Oryza sativa L. Cyanidin-3-glucoside on the Cognitive Function in Older Adults with Subjective Memory Impairment

OBJECTIVE

Cyanidin-3-glucoside (C3G), is a component of anthocyanin, have been considered to positively influence cognition and be beneficial for the prevention and treatment of dementia. We aimed to assess the safety and efficacy of cyanidin-3-glucoside-rich Oryza sativa L. (black rice) extract on cognitive function.

METHODS

A 12-weeks double-blind randomized, placebo controlled trial assessed safety and cognitive outcomes in participants with subjective memory impairment (n=48) following consumption of 6 black rice extract capsules or a placebo. Cognitive function was assessed using the ADAS-cog and the CERAD-K. Subjective memory impairment also assessed. Safety was assessed by hematologic blood test, urine analysis, and participant reports of adverse events.

RESULTS

There was significant improvement on subjective memory in intervention group. There was no statistically significant difference in objective cognitive outcomes following 12 weeks of consuming black rice extract. ADAS-cog scores, however, trended toward improvement in the intervention group compared to the placebo group. There was no adverse event.

CONCLUSION

Although significant improvement in objective cognitive function was not proved, we found that C3G-rich Oryza sativa L. extract improves subjective memory in this study. Therefore the results may be informative of the possible effectiveness of the C3G-rich Oryza sativa L. on cognitive function.

Comparison between red wine and isolated trans-resveratrol on the prevention and regression of atherosclerosis in LDLr (-/-) mice

Moderate consumption of red wine has been widely associated with reduced cardiovascular risk, mainly due to its composition in phenolic compounds with antioxidant activity, such as resveratrol. The objective of this study was to compare the effect of red wine vs. trans-resveratrol consumption on the prevention and regression of atherosclerosis in LDLr ^(-/-) mice. This study consisted of two protocols: "Prevention" (PREV) and "Regression" (REGR). Both protocols included four groups: red wine (WINE), dealcoholized red wine (EXT), trans-resveratrol (RESV), and control (CONT). In PREV protocol, animals received a regular diet for 8 weeks and then switched to an atherogenic diet for the following 8 weeks, while the opposite was performed in REGR. Animals that received atherogenic diet after an initial period of standard diet (PREV) gained more body weight (39.25±2.30%) than the opposite (29.27±1.91%, P=.0013), suggesting an interaction between age and weight gain. Trans-resveratrol showed the highest hypocholesterolemic effect during PREV, reducing total cholesterol, LDL-C, VLDL-C and HDL-C. Supplementation with trans-resveratrol and dealcoholized red wine changed the fatty acids profile in the liver in both protocols, leading to an increase of MDA concentrations and SOD activity in the PREV protocol. In conclusion, supplementation with trans-resveratrol, red wine and the same wine without alcohol altered biomarkers of oxidative stress and lipidemia but had no effect on the prevention or regression of fatty streaks. These data suggest that cardiovascular protection associated with the "French Paradox" may be a result of synergistic effects between wine and the Mediterranean diet.

Supplementation with curcumin inhibits intestinal cholesterol absorption and prevents atherosclerosis in high-fat diet-fed apolipoprotein E knockout mice

Atherosclerosis is a major cause of cardiovascular disease caused by high cholesterol. Reduced intestinal cholesterol absorption has been shown to exert strong cholesterol-lowering and antiatherogenic effects. Previously, we reported that curcumin reduced cholesterol absorption in high-fat diet-fed hamster by downregulating the intestinal expression of Niemann-Pick C1-like 1. Here, we tested the hypothesis that supplementation with curcumin can also reduce intestinal cholesterol absorption in high-fat diet-fed apolipoprotein E knockout (ApoE^-/-) mice and prevent atherosclerosis development. ApoE^-/- mice were fed a high-fat diet supplemented with or without curcumin (0.1% w/w) for 16 weeks. Aortic sinus sections revealed that curcumin supplementation reduced the extent of atherosclerotic lesions by 45%. Curcumin treatment also reduced cholesterol accumulation in the aortas by 56% and lowered plasma total cholesterol and low-density lipoprotein cholesterol levels. Moreover, the antiatherogenic and cholesterol-lowering effects of curcumin coincided with a significant decrease in intestinal cholesterol absorption. It was reduced by nearly 51%, and the decreased cholesterol absorption was modulated by inhibiting the intestinal expression of Niemann-Pick C1-like 1, predominantly in the duodenal and jejunal segments of the small intestine. These findings support the hypothesis that curcumin supplementation reduces intestinal cholesterol absorption and prevents atherosclerosis in high-fat diet-fed ApoE^-/- mice. Curcumin affords a potent antiatherogenic action by inhibiting intestinal cholesterol absorption in the mouse.

Wild Lonicera caerulea berry polyphenol extract reduces cholesterol accumulation and enhances antioxidant capacity in vitro and in vivo

The hypocholesterolemic effect of Lonicera caerulea berry extract rich in polyphenols (LCBP) on high cholesterol-induced hypercholesterolemia and lipoprotein metabolite changes was examined in Caco-2 cells and rats. Cyanidin-3-glucoside, catechin, and chlorogenic acid are the major phenolic components of LCBP. The cholesterol-reducing effect and antioxidant capacity of these components were compared in Caco-2 cells. LCBP (80 μg/mL) and cyanidin-3-glucoside, catechin, and chlorogenic acid (50 μM) were found to be effective (p < 0.05). Rats were fed a high cholesterol diet (HCD) with or without LCBP supplementation (75, 150, and 300 mg/kg body weight intragastrically once daily) for 12 weeks. Compared with the HCD control group, LCBP supplementation at 150 and 300 mg/kg decreased the levels of TC, TG, and LDL-C, but increased that of HDL-C. LCBP treatment promoted greater neutral and acidic sterol excretion (p < 0.05) and improved the antioxidant capacity of the colon tissue, colon contents, and blood. Moreover, trimethylamine N-oxide (TMAO) levels were decreased in serum (p < 0.05). NPC1L1, ACAT2, and MTP mRNA and protein expression were reduced and ABCG5/8 expression was increased (p < 0.05) after LCBP treatment. Our results suggest that LCBP could be used as a functional food for the prevention and treatment of diseases related to excessive cholesterol accumulation.

Curcumin Protects against Atherosclerosis in Apolipoprotein E-Knockout Mice by Inhibiting Toll-like Receptor 4 Expression

Toll-like receptor 4 (TLR4) has been reported to play a critical role in the pathogenesis of atherosclerosis, the current study aimed to investigate whether curcumin suppresses atherosclerosis development in ApoE-knockout (ApoE^-/-) mice by inhibiting TLR4 expression. ApoE^-/- mice were fed a high-fat diet supplemented with or without curcumin (0.1% w/w) for 16 weeks. Curcumin supplementation significantly reduced TLR4 expression and macrophage infiltration in atherosclerotic plaques. Curcumin also reduced aortic interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) expression, nuclear factor-κB (NF-κB) activity, and plasma IL-1β, TNF-α, soluble VCAM-1 and ICAM-1 levels. In addition, aortic sinus sections revealed that curcumin treatment reduced the extent of atherosclerotic lesions and inhibited atherosclerosis development. In vitro, curcumin inhibited NF-κB activation in macrophages and reduced TLR4 expression induced by lipopolysaccharide. Our results indicate that curcumin protects against atherosclerosis at least partially by inhibiting TLR4 expression and its related inflammatory reaction.

Cyanidin-3-O-glucoside: Physical-Chemistry, Foodomics and Health Effects

Anthocyanins (ACNs) are plant secondary metabolites from the flavonoid family. Red to blue fruits are major dietary sources of ACNs (up to 1 g/100 g FW), being cyanidin-3-O-glucoside (Cy3G) one of the most widely distributed. Cy3G confers a red hue to fruits, but its content in raspberries and strawberries is low. It has a good radical scavenging capacity (RSC) against superoxide but not hydroxyl radicals, and its oxidative potential is pH-dependent (58 mV/pH unit). After intake, Cy3G can be metabolized (phases I, II) by oral epithelial cells, absorbed by the gastric epithelium (1%-10%) and it is gut-transformed (phase II &amp; microbial metabolism), reaching the bloodstream (<1%) and urine (about 0.02%) in low amounts. In humans and Caco-2 cells, Cy3G's major metabolites are protocatechuic acid and phloroglucinaldehyde which are also subjected to entero-hepatic recycling, although caffeic acid and peonidin-3-glucoside seem to be strictly produced in the large bowel and renal tissues. Solid evidence supports Cy3G's bioactivity as DNA-RSC, gastro protective, anti-inflammatory, anti-thrombotic chemo-preventive and as an epigenetic factor, exerting protection against Helicobacter pylori infection, age-related diseases, type 2 diabetes, cardiovascular disease, metabolic syndrome and oral cancer. Most relevant mechanisms include RSC, epigenetic action, competitive protein-binding and enzyme inhibition. These and other novel aspects on Cy3G's physical-chemistry, foodomics, and health effects are discussed.

Cyanidin-3-O-β-glucoside Purified from Black Rice Protects Mice against Hepatic Fibrosis Induced by Carbon Tetrachloride via Inhibiting Hepatic Stellate Cell Activation

This study investigated whether cyanidin-3-O-β-glucoside (Cy-3-G), a predominant anthocyanin, could exert a protective role on liver injury and its further mechanisms of the anti-fibrosis actions in mice. The results demonstrated that the treatment of Cy-3-G (800 mg/kg diet) for 8 weeks significantly attenuated hepatotoxicity and fibrosis in carbon tetrachloride (CCl4) administered mice. Cy-3-G strongly down-regulated the expression of α-smooth muscle actin (α-SMA), desmin, and matrix metalloproteinase (MMPs), which showed its suppression effect on the activation of hepatic stellate cells (HSCs). In addition, Cy-3-G favorably regulated oxidative stress and apoptosis in liver. Furthermore, Cy-3-G ameliorated the infiltration of inflammatory cells such as neutrophils and leukocytes and meanwhile suppressed the production of pro-inflammatory cytokines and growth factors. In conclusion, daily intake of Cy-3-G could prevent liver fibrosis progression in mice induced by CCl4 through inhibiting HSC activation, which provides a basis for clinical practice of liver fibrosis prevention.

Role of gut microbiota in the modulation of atherosclerosis-associated immune response

Inflammation and metabolic abnormalities are linked to each other. At present, pathogenic inflammatory response was recognized as a major player in metabolic diseases. In humans, intestinal microflora could significantly influence the development of metabolic diseases including atherosclerosis. Commensal bacteria were shown to activate inflammatory pathways through altering lipid metabolism in adipocytes, macrophages, and vascular cells, inducing insulin resistance, and producing trimethylamine-N-oxide. However, gut microbiota could also play the atheroprotective role associated with anthocyanin metabolism and administration of probiotics and their components. Here, we review the mechanisms by which the gut microbiota may influence atherogenesis.

Mirtoselect, an anthocyanin-rich bilberry extract, attenuates non-alcoholic steatohepatitis and associated fibrosis in ApoE(∗)3Leiden mice

BACKGROUND & AIMS

Anthocyanins may have beneficial effects on lipid metabolism and inflammation and are demonstrated to have hepatoprotective properties in models of restraint-stress- and chemically-induced liver damage. However, their potential to protect against non-alcoholic steatohepatitis (NASH) under conditions relevant for human pathogenesis remains unclear. Therefore, we studied the effects of the standardised anthocyanin-rich extract Mirtoselect on diet-induced NASH in a translational model of disease.

METHODS

ApoE(∗)3Leiden mice were fed a Western-type cholesterol-containing diet without (HC) or with 0.1% (w/w) Mirtoselect (HCM) for 20weeks to study the effects on diet-induced NASH.

RESULTS

Mirtoselect attenuated HC-induced hepatic steatosis, as observed by decreased macro- and microvesicular hepatocellular lipid accumulation and reduced hepatic cholesteryl ester content. This anti-steatotic effect was accompanied by local anti-inflammatory effects in liver, as demonstrated by reduced inflammatory cell clusters and reduced neutrophil infiltration in HCM. On a molecular level, HC diet significantly induced hepatic expression of pro-inflammatory genes Tnf, Emr1, Ccl2, Mpo, Cxcl1, and Cxcl2 while this induction was less pronounced or significantly decreased in HCM. A similar quenching effect was observed for HC-induced pro-fibrotic genes, Acta2 and Col1a1 and this anti-fibrotic effect of Mirtoselect was confirmed histologically. Many of the pro-inflammatory and pro-fibrotic parameters positively correlated with intrahepatic free cholesterol levels. Mirtoselect significantly reduced accumulation and crystallisation of intrahepatic free cholesterol, providing a possible mechanism for the observed hepatoprotective effects.

CONCLUSIONS

Mirtoselect attenuates development of NASH, reducing hepatic lipid accumulation, inflammation and fibrosis, possibly mediated by local anti-inflammatory effects associated with reduced accumulation and crystallisation of intrahepatic free cholesterol.

Effects of Lycium barbarum polysaccharides on oxidative stress in hyperlipidemic mice following chronic composite psychological stress intervention

Chronic composite psychological stress intervention is the accumulation of factors which may induce psychological stress, including food deprivation, water deprivation and swimming in cold water. Approximately 40% of cases of atherosclerosis are associated with chronic composite psychological stress. The aim of the present study was to explore the effects of Lycium barbarum polysaccharides (LBP) on blood lipid levels and oxidative stress in hyperlipidemic mice, following chronic composite psychological stress. A hyperlipidemic mouse model was generated, and the mice were subjected to chronic composite psychological stress and treated with LBP for 30 days. After 30 days the triglyceride (TG) and total cholesterol (TC) levels were measured in the serum, and the mRNA expression levels of cholesterol 7α‑hydroxylase (CYP7A1) were determined in the liver, in order to observe any changes to lipid metabolism. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in the liver to evaluate the effects of LBP on oxidative stress. The blood serum levels of interleukin‑6 (IL‑6) and heat shock protein 70 (HSP‑70) were measured to evaluate the extent of the aortic inflammatory response, and to determine the protective effects of LBP. The levels of TG, TC, MDA and IL‑6 were significantly higher in the mice subjected to chronic composite psychological stress (HS), as compared with the mice treated with LBP alone (HL), or treated with LBP and subjected to stress (HLS). In addition, SOD and HSP‑70 levels, and the mRNA expression levels of CYP7A1 were significantly lower in the HS group, as compared with that in the HL and HLS groups. These results suggest that chronic composite psychological stress may promote the occurrence and development of atherosclerosis, by inducing the aortic inflammatory response and lipid peroxidation. Furthermore, treatment with LBP significantly inhibited oxidative stress and the aortic inflammatory response.

Black rice and anthocyanins induce inhibition of cholesterol absorption in vitro

Black rice (Oryza sativa L.) is often associated with blood lipid control. This study systematically assessed the inhibition of cholesterol absorption in vitro by black rice and explored cholesterol-lowering compounds present in this rice. Our results indicated that black rice extracts (BRE), which were aqueous, ethanol extracts and a fraction of macroporous resin caused the reduction of cholesterol absorption by inhibiting pancreatic lipase, decreasing the micellar cholesterol solubility and suppressing cholesterol uptake in Caco-2 cells. The inhibitory activity was positively associated with anthocyanin (cyanidin-3-glucoside (Cy-3-G) and peonidin-3-glucoside (Pn-3-G)) contents of the extracts. Therefore, the cholesterol absorption inhibiting properties of anthocyanins were further explored. The IC50 values of Cy-3-G and Pn-3-G against pancreatic lipase were 42.53 ± 4.45 and 18.13 ± 4.22 μg mL(-1), respectively. Kinetic analysis suggested that the enzymatic inhibitory mode of Cy-3-G and Pn-3-G belonged to the competitive type. In mixed micelles, Cy-3-G and Pn-3-G dose dependently reduced the solubility of cholesterol. Meanwhile, a potential mechanism of cholesterol reduction by anthocyanins was investigated. Results showed that anthocyanins led to precipitation of cholesterol from micellar solution, which may induce the reduction of cholesterol. In Caco-2 cells, Cy-3-G and Pn-3-G (40 μg mL(-1)) exhibited a significant reduction in cholesterol uptake, and the degree of this reduction was almost the same as that observed in the group treated with Ezetimibe at the same concentration. These findings provide important evidence that anthocyanins may partly contribute to the inhibitory effects of black rice on cholesterol absorption, and thus may be applied for the prevention and treatment of hypercholesterolaemia.

Cyanidin-3-O-β-glucoside inhibits lipopolysaccharide-induced inflammatory response in mouse mastitis model

Cyanidin-3-O-β-glucoside (C3G) (CAS number 7084-24-4), a typical anthocyanin pigment that exists in the human diet, has been reported to have anti-inflammatory properties. However, the effect of C3G on lipopolysaccharide (LPS)-induced mastitis and the molecular mechanisms have not been investigated. In this study, we detected the protective effects of C3G on a LPS-induced mouse mastitis model and investigated the molecular mechanisms in LPS-stimulated mouse mammary epithelial cells (MMECs). Our results showed that C3G could attenuate mammary histopathologic changes and myeloperoxidase activity, and inhibit TNF-α, interleukin (IL)-1β, and IL-6 production caused by LPS. Meanwhile, C3G dose-dependently inhibited TNF-α and IL-6 in LPS-stimulated MMECs. C3G suppressed LPS-induced nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) activation. Furthermore, C3G disrupted the formation of lipid rafts by depleting cholesterol. Moreover, C3G activated liver X receptor (LXR)-ABCG1-dependent cholesterol efflux. Knockdown of LXRα abrogated the anti-inflammatory effects of C3G. In conclusion, C3G has a protective effect on LPS-induced mastitis. The promising anti-inflammatory mechanisms of C3G are associated with upregulation of the LXRα-ABCG1 pathway which result in disrupting lipid rafts by depleting cholesterol, thereby suppressing toll-like receptor 4-mediated NF-κB and IRF3 signaling pathways induced by LPS.

Anthocyanin supplementation improves HDL-associated paraoxonase 1 activity and enhances cholesterol efflux capacity in subjects with hypercholesterolemia

CONTEXT AND OBJECTIVE

Paraoxonase 1 (PON1), an enzyme associated with high-density lipoprotein (HDL-PON1), is reported to have antioxidant and cardioprotective properties. The aim of the present study was to investigate the effects of anthocyanins on the HDL-PON1 activity and cholesterol efflux capacity in hypercholesterolemic subjects.

DESIGN AND PARTICIPANTS

A total of 122 hypercholesterolemic subjects were given 160 mg of anthocyanins twice daily or placebo (n = 61 of each group) for 24 weeks in a double-blind, randomized, placebo-controlled trial. Participants and investigators were masked to treatment allocation.

RESULTS

Anthocyanin consumption significantly increased HDL cholesterol and decreased low -density lipoprotein cholesterol concentrations compared with placebo (P < .018 and P < .001, respectively). Anthocyanin supplementation also increased the activity of HDL-PON1 compared with placebo (P < .001). Furthermore, cholesterol efflux capacity was increased more in the anthocyanin group (20.0% increase) than in the placebo group (0.2% increase) (P < .001). The negative correlations established between HDL-PON1 activity and the levels of lipid hydroperoxides associated with HDL confirm the relationship between PON1 activity and lipid peroxidation of lipoproteins. Furthermore, a strong positive correlation was noted between increased HDL-PON1 activity and improved cholesterol efflux capacity both before and after adjustment for HDL cholesterol and apolipoprotein AI in anthocyanin-treated subjects (both P < .001). Inhibition of HDL-PON1 activity strongly prevented the antioxidant ability of HDL and attenuated the cholesterol efflux capacity of subjects from anthocyanin group.

CONCLUSIONS

Our observations suggest that the alterations of PON1 activity by anthocyanin observed in hypercholesterolemic HDL reflect a shift to an improvement of cholesterol efflux capacity of HDL and may provide a link between anthocyanin and cardioprotective effects.

Hypolipidaemic effects of cyanidin 3-glucoside rich extract from black rice through regulating hepatic lipogenic enzyme activities

BACKGROUND

Black rice is rich in anthocyanins, especially cyanidin-3-glucoside (C3G). This study examined the effects of a C3G-rich extract from black rice on hyperlipidaemia induced by a high fat/cholesterol diet (HFCD) in rats.

RESULTS

Male Sprague-Dawley rats were fed either HFCD or HFCD containing 150 mg kg⁻¹ body weight C3G (HFCD+C3G) for 4 weeks. We found that C3G significantly decreased serum levels of total cholesterol, free cholesterol, triglycerides, and free fatty acids in rats fed a HFCD. Similarly, hepatic cholesterol and triglyceride levels and the activities of hepatic lipogenic enzymes (malic enzyme and glucose-6-phosphate dehydrogenase) were significantly reduced by C3G supplementation.

CONCLUSION

These results suggest that C3G can ameliorate HFCD-induced hyperlipidaemia in part by modulating the activities of hepatic lipogenic enzymes.

Expression and regulation of cholesterol 7 alpha-hydroxylase: An update

Cholesterol 7-alpha hydroxylase (CYP7A1) is the first and rate-limiting enzyme in the neutral pathway of bile acids synthesis. The expression of CYP7A1 can be regulated not only by diurnal rhythm, but also by gene polymorphism, diet, hormones, cytokines and drugs. CYP7A1 gene polymorphism is associated not only with some diseases but also with response to drug therapy. A cascade network consisting of multiple nuclear receptors is involved in the regulation of CYP7A1 expression to control bile acid synthesis and lipid metabolism.