Trimethylamine N-oxide, choline and its metabolites are associated with the risk of non-alcoholic fatty liver disease

It is inconclusive whether trimethylamine N-oxide (TMAO) and choline and related metabolites, namely trimethylamine (TMA), l-carnitine, betaine and dimethylglycine (DMG), are associated with non-alcoholic fatty liver disease (NAFLD). Our objective was to investigate these potential associations. Additionally, we sought to determine the mediating role of TMAO. In this 1:1 age- and sex-matched case-control study, a total of 150 pairs comprising NAFLD cases and healthy controls were identified. According to the fully adjusted model, after the highest tertile was compared with the lowest tertile, the plasma TMAO concentration (OR = 2·02 (95 % CI 1·04, 3·92); P trend = 0·003), l-carnitine concentration (OR = 1·79 (1·01, 3·17); P trend = 0·020) and DMG concentration (OR = 1·81 (1·00, 3·28); P trend = 0·014) were significantly positively associated with NAFLD incidence. However, a significantly negative association was found for plasma betaine (OR = 0. 50 (0·28, 0·88); P trend = 0·001). The restricted cubic splines model consistently indicated positive dose-response relationships between exposure to TMAO, l-carnitine, and DMG and NAFLD risk, with a negative association being observed for betaine. The corresponding AUC increased significantly from 0·685 (0·626, 0·745) in the traditional risk factor model to 0·769 (0·716, 0·822) when TMAO and its precursors were included (l-carnitine, betaine and choline) (P = 0·032). Mediation analyses revealed that 14·7 and 18·6 % of the excess NAFLD risk associated with l-carnitine and DMG, respectively, was mediated by TMAO (the P values for the mediating effects were 0·021 and 0·036, respectively). These results suggest that a higher concentration of TMAO is associated with increased NAFLD risk among Chinese adults and provide evidence of the possible mediating role of TMAO.

Therapeutic potential of traditional Chinese medicine in the prevention and treatment of digestive inflammatory cancer transformation: Portulaca oleracea L. as a promising drug

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) has been used for centuries to treat various types of inflammation and tumors of the digestive system. Portulaca oleracea L. (POL), has been used in TCM for thousands of years. The chemical composition of POL is variable and includes flavonoids, alkaloids, terpenoids and organic acids and other classes of natural compounds. Many of these compounds exhibit powerful anti-inflammatory and anti-cancer-transforming effects in the digestive system.

AIM OF STUDY

In this review, we focus on the potential therapeutic role of POL in NASH, gastritis and colitis and their associated cancers, with a focus on the pharmacological properties and potential mechanisms of action of the main natural active compounds in POL.

METHODS

The information and data on Portulaca oleracea L. and its main active ingredients were collated from various resources like ethnobotanical textbooks and literature databases such as CNKI, VIP (Chinese literature), PubMed, Science Direct, Elsevier and Google Scholar (English literatures), Wiley, Springer, Tailor and Francis, Scopus, Inflibnet.

RESULTS

Kaempferol, luteolin, myricetin, quercetin, genistein, EPA, DHA, and melatonin were found to improve NASH and NASH-HCC, while kaempferol, apigenin, luteolin, and quercetin played a therapeutic role in gastritis and gastric cancer. Apigenin, luteolin, myricetin, quercetin, genistein, lupeol, vitamin C and melatonin were found to have therapeutic effects in the treatment of colitis and its associated cancers. The discovery of the beneficial effects of these natural active compounds in POL supports the idea that POL could be a promising novel candidate for the treatment and prevention of inflammation-related cancers of the digestive system.

CONCLUSION

The discovery of the beneficial effects of these natural active compounds in POL supports the idea that POL could be a promising novel candidate for the treatment and prevention of inflammation-related cancers of the digestive system. However, clinical data describing the mode of action of the naturally active compounds of POL are still lacking. In addition, pharmacokinetic data for POL compounds, such as changes in drug dose and absorption rates, cannot be extrapolated from animal models and need to be measured in patients in clinical trials. On the one hand, a systematic meta-analysis of the existing publications on TCM containing POL still needs to be carried out. On the other hand, studies on the hepatic and renal toxicity of POL are also needed. Additionally, well-designed preclinical and clinical studies to validate the therapeutic effects of TCM need to be performed, thus hopefully providing a basis for the validation of the clinical benefits of POL.

Human diet-derived polyphenolic compounds and hepatic diseases: From therapeutic mechanisms to clinical utilization

This review focuses on the potential ameliorative effects of polyphenolic compounds derived from human diet on hepatic diseases. It discusses the molecular mechanisms and recent advancements in clinical applications. Edible polyphenols have been found to play a therapeutic role, particularly in liver injury, liver fibrosis, NAFLD/NASH, and HCC. In the regulation of liver injury, polyphenols exhibit anti-inflammatory and antioxidant effects, primarily targeting the TGF-β, NF-κB/TLR4, PI3K/AKT, and Nrf2/HO-1 signaling pathways. In the regulation of liver fibrosis, polyphenolic compounds effectively reverse the fibrotic process by inhibiting the activation of hepatic stellate cells (HSC). Furthermore, polyphenolic compounds show efficacy against NAFLD/NASH by inhibiting lipid oxidation and accumulation, mediated through the AMPK, SIRT, and PPARγ pathways. Moreover, several polyphenolic compounds exhibit anti-HCC activity by suppressing tumor cell proliferation and metastasis. This inhibition primarily involves blocking Akt and Wnt signaling, as well as inhibiting the epithelial-mesenchymal transition (EMT). Additionally, clinical trials and nutritional evidence support the notion that certain polyphenols can improve liver disease and associated metabolic disorders. However, further fundamental research and clinical trials are warranted to validate the efficacy of dietary polyphenols.

Myricetin possesses the potency against SARS-CoV-2 infection through blocking viral-entry facilitators and suppressing inflammation in rats and mice

BACKGROUND

Myricetin (3,5,7-trihydroxy-2-(3,4,5-tri hydroxyphenyl)-4-benzopyrone) is a common flavonol extracted from many natural plants and Chinese herb medicines and has been demonstrated to have multiple pharmacological activities, such as anti-microbial, anti-thrombotic, neuroprotective, and anti-inflammatory effects. Previously, myricetin was reported to target Mpro and 3CL-Pro-enzymatic activity to SARS-CoV-2. However, the protective value of myricetin on SARS-Cov-2 infection through viral-entry facilitators has not yet been comprehensively understood.

PURPOSE

The aim of the current study was to evaluate the pharmacological efficacy and the mechanisms of action of myricetin against SARS-CoV-2 infection both in vitro and in vivo.

METHODS

The inhibitory effects of myricetin on SARS-CoV-2 infection and replication were assessed on Vero E6 cells. Molecular docking analysis and bilayer interferometry (BLI) assays, immunocytochemistry (ICC), and pseudoviruses assays were performed to evaluate the roles of myricetin in the intermolecular interaction between the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein and angiotensin-converting enzyme 2 (ACE2). The anti-inflammatory potency and mechanisms of myricetin were examined in THP1 macrophages in vitro, as well as in carrageenan-induced paw edema, delayed-type hypersensitivity (DTH) induced auricle edema, and LPS-induced acute lung injury (ALI) animal models.

RESULTS

The results showed that myricetin was able to inhibit binding between the RBD of the SARS-CoV-2 S protein and ACE2 through molecular docking analysis and BLI assay, demonstrating its potential as a viral-entry facilitator blocker. Myricetin could also significantly inhibit SASR-CoV-2 infection and replication in Vero E6 cells (EC₅₀ 55.18 μM), which was further validated with pseudoviruses containing the RBD (wild-type, N501Y, N439K, Y453F) and an S1 glycoprotein mutant (S-D614G). Moreover, myricetin exhibited a marked suppressive action on the receptor-interacting serine/threonine protein kinase 1 (RIPK1)-driven inflammation and NF-kappa B signaling in THP1 macrophages. In animal model studies, myricetin notably ameliorated carrageenan-induced paw edema in rats, DTH induced auricle edema in mice, and LPS-induced ALI in mice.

CONCLUSION

Our findings showed that myricetin inhibited HCoV-229E and SARS-CoV-2 replication in vitro, blocked SARS-CoV-2 virus entry facilitators and relieved inflammation through the RIPK1/NF-κB pathway, suggesting that this flavonol has the potential to be developed as a therapeutic agent against COVID-19.

Dietary Methionine Restriction Promotes Fat Browning and Attenuates Hepatic Lipid Accumulation in High-Choline-Fed Mice Associated with the Improvement of Thyroid Function

This study aims to explore the influences of a methionine-restricted diet (MRD) on fat browning and hepatic lipid accumulation in mice fed with a high-choline diet (HCD) and their possible mechanisms. ICR mice were randomly divided into three groups and fed with a normal diet (0.86% methionine + 0.20% choline, ND), HCD (0.86% methionine + 1.20% choline), or MRD (0.17% methionine + 1.20% choline) for 90 consecutive days. We found that MRD reduced body weight and fat mass; increased heat production and ambulatory locomotor activity; reduced hepatic and plasma lipid levels, hepatic fatty infiltration area, and adipocyte volume in white and brown adipose tissue; promoted fat browning, especially upregulated gene and protein expression levels of uncoupling protein 1 (UCP1); and promoted fat catabolism and inhibited fat anabolism in the liver and adipose tissue. Moreover, MRD increased antioxidant defenses and reduced inflammatory cytokine levels in the thyroid, blood, and liver. Furthermore, MRD improved thyroid morphological structure, promoted the synthesis and secretion of thyroid hormones, and enhanced the actions of thyroid hormones on its receptor organs (liver and adipose tissue). These findings suggested that MRD promoted fat browning and attenuated hepatic lipid accumulation in HCD mice associated with the improvement of thyroid function.

Quercetin inhibits hepatotoxic effects by reducing trimethylamine-N-oxide formation in C57BL/6J mice fed with a high L-carnitine diet

L-Carnitine can be metabolized to trimethylamine (TMA) by gut microbiota and further converted into trimethylamine N-oxide (TMAO) in the liver, leading to liver damage. This study aimed to investigate the protective effect of quercetin against high L-carnitine-induced liver toxicity in mice. 3% L-carnitine drinking water was used to feed mice in this study. The formation of TMAO in the blood circulation of the tested mice was down-regulated following quercetin treatment. Administration of quercetin could also effectively antagonize the liver injury caused by high L-carnitine intake, which was proved by the decreased serum AST and ALT activities and the reduced levels of inflammatory liver cytokines (IL-1, IL-6, TNF-α, and TNF-β). Moreover, quercetin exhibited a rebalancing effect on dyslipidemia (TC, TG, HDL, and LDL) and antioxidant abilities (SOD, GSH-Px, MDA, and RAHFR) in L-carnitine-treated mice. The results of hepatic H&E and Oil Red O staining further verified the liver injury of high L-carnitine-treated mice and the protective effects of quercetin. These findings suggested that quercetin could attenuate the hepatotoxic effects of the mice fed with a high L-carnitine diet via inhibiting the circulating TMAO formation.

Gastroprotective Effect of Myricetin on Ethanol-Induced Acute Gastric Injury in Rats

The flavonoid myricetin is abundant in vegetables and has various bioactive properties, including anti-inflammatory and antioxidative activities. In the present study, we explored the effects of myricetin on alcohol-induced gastric ulcer in a rat model. To induce gastric ulcer, absolute ethanol (5 mL/kg body weight) was orally administrated to each rat. The positive control and myricetin-treated groups were given oral doses of omeprazole (20 mg/kg) or myricetin (12 mg/kg), respectively, 1 hour prior to the administration of absolute alcohol. We found that pretreatment with myricetin significantly decreased alcohol-induced gastric ulcer, hemorrhage, hyperemia, and epithelial cell loss in the gastric mucosa. Myricetin pretreatment reduced the level of malondialdehyde (MDA) and increased that of total glutathione (GSSG/GSH) and superoxide dismutase (SOD) in gastric tissues. In addition, it elevated the expression levels of cyclooxygenase-1 (COX-1) and prostaglandin E₂ (PGE₂) and decreased the phosphorylation of nuclear factor kappa B (NF-κB). Together, these results indicate that myricetin effectively inhibits ethanol-induced acute gastric injury by preventing oxidative damage, stimulating PGE₂ production, and inhibiting NF-κB activation. We suggest that myricetin may be an alternative treatment for gastric injury caused by alcohol intake.

Hybrid Poly(AMPS-CS)-Au Microneedle Arrays to Enrich Metabolites from Skin for Early Disease Diagnosis

Recently, some metabolites in skin interstitial fluid (SIF) have become emerging re×sources for early disease diagnosis. However, their low level in SIF and difficulty to sampling are the biggest obstacle to further potential application. Here, a swellable microneedle array patch (MNAP) with high mechanical strength is presented, and the rapid enrichment of positively charged metabolites is achieved. The MNAP is fabricated by poly (chondroitin sulfate-acrylamido-2-methylpropane sulfonic acid)-gold nanoparticles (GNPs) composites via a micro-molding. The negatively charged copolymer hydrogel not only enrich positively charged metabolites, but also provide swellable capacity. The in situ synthesis of GNPs in the process of copolymerization make the GNPs cross-link to the hydrogel, which further enhance the MNAP mechanical strength and enrichment efficiency for positively charged metabolites. By using the MNAP, around 5 mg SIF in 10 min from the high fat/cholecalciferol/methimazole-induced atherogenesis rat is extracted and 23 metabolites including 13 quaternary ammonium cationic compounds can be detected and quantified by using a LC-QTOF-MS. Dysregulated L-carnitine and choline metabolism are discovered a week earlier in the SIF than in the serum, achieving early diagnosis of the metabolism syndrome disease. This MNAP also helps users complete home sampling for early disease diagnosis and monitoring.

Myricetin: A comprehensive review on its biological potentials

Myricetin is a critical nutritive component of diet providing immunological protection and beneficial for maintaining good health. It is found in fruits, vegetables, tea, and wine. The families Myricaceae, Polygonaceae, Primulaceae, Pinaceae, and Anacardiaceae are the richest sources of myricetin. Different researchers explored the therapeutic potential of this valuable constituent such as anticancer, antidiabetic, antiobesity, cardiovascular protection, osteoporosis protection, anti-inflammatory, and hepatoprotective. In addition to these, the compound has been tested for cancer and diabetic mellitus during clinical trials. Health benefits of myricetin are related to its impact on different cell processes, such as apoptosis, glycolysis, cell cycle, energy balance, lipid level, serum protein concentrations, and osteoclastogenesis. This review explored the potential health benefits of myricetin with a specific emphasis on its mechanism of action, considering the most updated and novel findings in the field.

Association between Dietary Choline Intake and Diabetic Retinopathy: National Health and Nutrition Examination Survey 2005-2008

PURPOSE

To explore whether there is an association between dietary choline intake and odds of diabetic retinopathy (DR) in the US diabetic population.

METHODS

A cross-sectional study was conducted using the combined data of the National Health and Nutrition Examination Survey (NHANES) 2005-2008 of a complex, multistage, and probability-sampling design. Energy-adjusted choline intake was calculated separately for men and women using the residual method. Binary logistic regression adjusting for covariates was used to identify the variables associated with DR.

RESULTS

We included 644 male and 628 female diabetic subjects, which were equivalent to a weighted survey sample of 9,339,124 for males and 10,109,553 for females respectively. Female DR patients consumed more choline than non-DR patients (268.6 mg/d vs 250.9 mg/d; p = .046). The estimated prevalence of DR was 17.4%, 21.9%, and 29.7% across three levels of dietary choline intake in females, respectively. In multivariable logistic-regression models, the odds ratio (OR) of DR for female patients in the highest choline intake group was 2.14 (95% confidence interval [CI], 1.38-3.31; p = .001) compared with those in the lowest intake group. This association was positive but not statistically significant in males.

CONCLUSION

Higher intake of dietary choline is associated with increased odds of DR in females, but not in males. Further studies are warranted to investigate the direct role of choline in DR development and determine the recommended daily intake of choline for diabetic patients weighing the pros and cons of dietary choline consumption.

Quality control of Semen Hoveniae by high-performance liquid chromatography coupled to Fourier transform-ion cyclotron resonance mass spectrometry

A method based on high-performance liquid chromatography and Fourier transform-ion cyclotron resonance mass spectrometry was developed to control the quality of Semen Hoveniae. First, the chromatographic fingerprint was established in combination with the chemometrics methods such as similarity analysis, cluster analysis, principal component analysis, and orthogonal partial least squares discriminant analysis to discover the qualitative markers. Then, an high-performance liquid chromatography mass spectrometry method was developed to identify the chemical constituents in Semen Hoveniae. Moreover, the content of dihydromyricetin and dihydroquercetin in Semen Hoveniae were determined by high-performance liquid chromatography. As a result, nine common peaks were assigned in the fingerprints and the similarity of the 13 batch samples varied from 0.425 to 0.993, indicating an obviously different quality. Dihydromyricetin and dihydroquercetin were the main qualitative markers to differ the quality of Semen Hoveniae. Meanwhile, a total of 21 chemical compounds were characterized by high-performance liquid chromatography mass spectrometry and six of them were identified by comparing with information of reference standards. Finally, the content of dihydromyricetin and dihydroquercetin in 13 batch samples varied from 0.824  to 7.499 mg/g and from 0.05941  to 4.258 mg/g , respectively. In conclusion, the methods developed here will provide sufficient qualitative and quantitative information for the quality control of Semen Hoveniae.

Metabonomic Study on the Plasma of High-Fat Diet-Induced Dyslipidemia Rats Treated with Ge Gen Qin Lian Decoction by Ultrahigh-Performance Liquid Chromatography-Mass Spectrometry

Gegen Qinlian decoction (GGQLD) has a definite effect on T2DM in clinic, and it has the effect of lowering blood sugar, improving insulin resistance, and improving the blood lipid level of rats with dyslipidemia, but the intervention mechanism of GGQLD on dyslipidemia has not been clarified. The changes in endogenous metabolites in the plasma of high-fat diet-induced dyslipidemia rats treated with Ge Gen Qin Lian Decoction (GGQLD) were studied to elucidate the therapeutic effects and mechanism of action of GGQLD in dyslipidemia. Based on ultrahigh-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS), the metabolic profiles of rat serum samples were collected. The rat model of dyslipidemia was induced by a 60% fat-fed high-fat diet. After feeding the rats with a high-fat diet for 4 weeks, dyslipidemia appeared. After 5 weeks of GGQLD (14.85 g kg⁻¹) administration, the metabonomics of rats' plasma samples in the normal group, model group, and administration group were analyzed. Mass profiler professional (MPP), SIMCA-P 14.1, and Graphpad prism 6.0 software were used combined with METLIN biological database and human metabolite database HMDB to screen and identify endogenous biomarkers. Metaboanalyst 4.0 software was used by combining with HMDB and KEGG databases; the enrichment and metabolic pathway of biomarkers were analyzed to explore the metabolic mechanism of dyslipidemia rats induced by high-fat diet and the intervention mechanism of Gegen Qinlian decoction. After 5 weeks of administration of GGQLD, the levels of serum TC and TG were significantly decreased (P < 0.05, P < 0.01), while HDL-C and LDL-C were not significantly affected. After administration, the food intake of rats in the administration group decreased gradually, and the change trend of body weight gradually slowed down. The metabonomics of rat plasma samples results showed that 23 potential biomarkers including α-linolenic acid, arachidonic acid, and lysophosphatidylcholine were significantly changed in positive ion mode. Studies have shown that GGQLD has a significant lipid-lowering effect on dyslipidemia rats induced by a high-fat diet, and its preventive mechanism is related to tryptophan metabolism, fatty acid biosynthesis, α-linolenic acid metabolism, arachidonic acid, and glycerophosphatidyl metabolism pathway.

The Emerging Roles of Antioxidant Enzymes by Dietary Phytochemicals in Vascular Diseases

Vascular diseases are major causes of death worldwide, causing pathologies including diabetes, atherosclerosis, and chronic obstructive pulmonary disease (COPD). Exposure of the vascular system to a variety of stressors and inducers has been implicated in the development of various human diseases, including chronic inflammatory diseases. In the vascular wall, antioxidant enzymes form the first line of defense against oxidative stress. Recently, extensive research into the beneficial effects of phytochemicals has been conducted; phytochemicals are found in commonly used spices, fruits, and herbs, and are used to prevent various pathologic conditions, including vascular diseases. The present review aims to highlight the effects of dietary phytochemicals role on antioxidant enzymes in vascular diseases.

Natural Aldose Reductase Inhibitor: A Potential Therapeutic Agent for Non-alcoholic Fatty Liver Disease

Aldose reductase (AR) has been reported to be involved in the development of nonalcoholic fatty liver disease (NAFLD). Hepatic AR is induced under hyperglycemia condition and converts excess glucose to lipogenic fructose, which contributes in part to the accumulation of fat in the liver cells of diabetes rodents. In addition, the hyperglycemia-induced AR or nutrition-induced AR causes suppression of the transcriptional activity of peroxisome proliferator-activated receptor (PPAR) α and reduced lipolysis in the liver, which also contribute to the development of NAFLD. Moreover, AR induction in non-alcoholic steatohepatitis (NASH) may aggravate oxidative stress and the expression of inflammatory cytokines in the liver. Here, we summarize the knowledge on AR inhibitors of plant origin and review the effect of some plant-derived AR inhibitors on NAFLD/NASH in rodents. Natural AR inhibitors may improve NAFLD at least in part through attenuating oxidative stress and inflammatory cytokine expression. Some of the natural AR inhibitors have been reported to attenuate hepatic steatosis through the regulation of PPARα-mediated fatty acid oxidation. In this review, we propose that the natural AR inhibitors are potential therapeutic agents for NAFLD.

Hawthorn fruit extract reduced trimethylamine-N-oxide (TMAO)-exacerbated atherogenesis in mice via anti-inflammation and anti-oxidation

Background

Trimethylamine-N-oxide (TMAO) is an independent risk factor for atherosclerosis. Consumption of hawthorn fruit is believed to be cardio-protective, yet whether it is able to suppress the TMAO-induced atherosclerosis remains unexplored. The present study was to investigate the effects of hawthorn fruit extract (HFE) on TMAO-exacerbated atherogenesis.

Methods

Five groups of male Apolipoprotein E knock-out (ApoE^−/−) mice were fed a low-fat diet (LFD), a Western high-fat diet (WD), or one of the three WDs containing 0.2% TMAO (WD + TMAO), 0.2% TMAO plus 1% HFE (WD + TMAO + L-HFE), or 0.2% TMAO plus 2% HFE (WD + TMAO + H-HFE), respectively. After 12-weeks of intervention, plasma levels of TMAO, lipid profile, inflammatory biomarkers, and antioxidant enzyme activities were measured. Atherosclerotic lesions in the thoracic aorta and aortic sinus were evaluated. The sterols and fatty acids in the liver and feces were extracted and measured. Hepatic expressions of inflammatory biomarkers and antioxidant enzymes were analyzed.

Results

Dietary TMAO accelerated atherogenesis, exacerbated inflammation, and reduced antioxidant capacities in the plasma and the liver. TMAO promoted hepatic cholesterol accumulation by inhibiting fecal excretion of acidic sterols. HFE could dose-dependently reduce the TMAO-aggravated atherosclerosis and inflammation. HFE was also able to reverse the TMAO-induced reduction in antioxidant capacity by up-regulating the expression of antioxidant enzymes including superoxide dismutase 1 (SOD1), SOD2, glutathione peroxidase 3 (GSH-Px3), and catalase (CAT) in the liver. Moreover, the hepatic cholesterol content was lowered by HFE via enhanced fecal excretion of neutral and acidic sterols.

Conclusions

The present results indicated that HFE was able to reduce the TMAO-exacerbated atherogenesis by attenuating inflammation and improving antioxidant capacity at least in mice.

Graphic abstract

Circulating choline is associated with coronary artery stenosis in patients with hypertension: A cross-sectional study of Chinese adults

Choline is an important nutrient involved in multiple biosynthesis pathways. However, whether circulating choline levels are associated with the risk of hypertension (HTN) and artery stenosis in HTN remains unknown. We investigated the correlations of plasma choline with HTN and coronary artery injury and explored the utility of plasma choline as a diagnostic biomarker for HTN and artery stenosis. 193 HTN patients and 154 age- and sex-matched healthy controls (CON) were recruited in this study. Fasting plasma choline was detected using liquid chromatography tandem mass spectrometry. Choline levels were significantly higher in HTN without artery stenosis (HTN-AS) than CON (8.07 [7.19-9.24] μM vs 7.03 [6.21-8.13] μM, P < .01) group and were further upregulated in HTN with artery stenosis (HTN + AS) (8.63 [7.09-10.59] μM, P < .01) group. Patients with multivessel disease (MVD) also exhibited higher choline levels than those with single vessel disease (SVD) (8.64 [7.16-10.55] μM vs 8.04(6.74-9.38) μM, P < .01). Increased choline levels were independently associated with the risk of HTN (OR = 1.2, 95% CI: 1-1.45, P = .05), HTN + AS (OR = 1.27, 95% CI: 1.09-1.48, P < .01), and MVD (OR = 1.16, 95% CI: 1.02-1.31, P = .02) after adjustment for multiple risk factors. Receiver operating characteristic (ROC) analysis showed that choline had an area under curve (AUC) score of 0.69, 0.67, and 0.63 in determining HTN, HTN + AS, and MVD. In conclusion, higher choline levels were associated with increased risk of HTN and artery stenosis in hypertensive patients.

Effects of choline supplementation on liver biology, gut microbiota, and inflammation in Helicobacter pylori-infected mice

AIMS

Diet is one of the factors affecting the pathogenicity of Helicobacter pylori (H. pylori) infection. Choline is a dietary component that is crucial for normal cellular function. However, choline intake imbalance can lead to liver injury, inflammation, and changes of the gut microbiota composition. The study aimed to explore the effects of choline supplementation on liver biology, gut microbiota, and inflammation in H. pylori-infected mice.

MAIN METHODS

Liver function was detected by biochemical and histopathological analysis. Serum inflammatory markers were measured using ELISA. Fecal microbial profiles were determined via 16S rRNA sequencing.

KEY FINDINGS

The results showed that choline supplementation decreased serum LDL level, while increased the activities of serum AST and ALT in normal BALB/c mice. Besides, choline also reduced hepatic SOD and GSH-Px activities, and elevated hepatic MDA level of H. pylori-infected mice. Moreover, choline markedly enhanced the concentrations of inflammatory factors including LPS, CRP, IL-6, TNF-α, and CXCL1 in H. pylori-infected mice. Meanwhile, choline and H. pylori cotreatment altered the richness and diversity of the mice gut microbiota, and increased the relative abundance of Escherichia_Shigella, which had a significant positive correlation with the levels of LPS, CRP, IL-6, TNF-α and CXCL1.

SIGNIFICANCE

Our data suggest, for the first time, that choline can aggravate H. pylori-induced inflammation, which may be associated with the alterations of gut microbiota. This study may provide novel insights into the possible effects of food-derived choline on H. pylori infection-related diseases.

Dietary bioactive ingredients to modulate the gut microbiota-derived metabolite TMAO. New opportunities for functional food development

There is a growing body of clinical evidence that supports a strong association between elevated circulating trimethylamine N-oxide (TMAO) levels with increased risk of developing adverse cardiovascular outcomes such as atherosclerosis and thrombosis. TMAO is synthesized through a meta-organismal stepwise process that involves (i) the microbial production of TMA in the gut from dietary precursors and (ii) its subsequent oxidation to TMAO by flavin-containing monooxygenases in the liver. Choline, l-carnitine, betaine, and other TMA-containing compounds are the major dietary precursors of TMA. TMAO can also be absorbed directly from the gastrointestinal tract after the intake of TMAO-rich foods such as fish and shellfish. Thus, diet is an important factor as it provides the nutritional precursors to eventually produce TMAO. A number of studies have attempted to associate circulating TMAO levels with the consumption of diets rich in these foods. On the other hand, there is growing interest for the development of novel food ingredients that reduce either the TMAO-induced damage or the endogenous TMAO levels through the interference with microbiota and host metabolic processes involved in TMAO pathway. Such novel functional food ingredients would offer great opportunities to control circulating TMAO levels or its effects, and potentially contribute to decrease cardiovascular risk. In this review we summarize and discuss current data regarding the effects of TMA precursors-enriched foods or diets on circulating TMAO levels, and recent findings regarding the circulating TMAO-lowering effects of specific foods, food constituents and phytochemicals found in herbs, individually or in extracts, and their potential beneficial effect for cardiovascular health.

The Protective Effects of Myricetin against Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death globally, except Africa, and poses a severe health burden worldwide. Both in vitro and in vivo studies have demonstrated the protective effects of myricetin for preventing CVD. For this review, we have assessed the literature from 2009 to 2019 at home and abroad to uncover the protective roles of myricetin for preventing CVD. Myricetin exhibits cardioprotective, anti-hypertensive, anti-atherosclerotic, anti-hyperglycemic, and anti-hyperlipidemic effects. In addition, myricetin may alleviate some of the complications caused by adult-onset diabetes. The combined functions of myricetin allow for the prevention of CVD. This review describes the possible therapeutic benefits of myricetin, along with its potential mechanisms of action, to support the clinical use of the myricetin for the prevention of CVD.

Myricetin Modulates Macrophage Polarization and Mitigates Liver Inflammation and Fibrosis in a Murine Model of Nonalcoholic Steatohepatitis

This study aimed to investigate the beneficial effects of myricetin in a diet-induced nonalcoholic steatohepatitis (NASH) model and the underlying mechanism. C57BL/6J mice were fed a standard chow or the choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) for 8 weeks with the treatment of myricetin (100 mg/kg) or vehicle by daily gavage. Hepatic inflammation, steatosis, fibrosis, and hepatic stellate cells (HSC) activation were assessed. We also analyzed M1 and M2 macrophages and its related markers in livers from NASH mice and in RAW264.7 macrophages stimulated by lipopolysaccharide (LPS) or interleukin 4 (IL-4) in vitro. Furthermore, we determined the effect of myricetin on the triggering receptor expressed on myeloid cells-1 (TREM-1), toll like receptor (TLR) 2 and 4, and myeloid differentiation factor 88 (MyD88) signaling both in livers from mice and in RAW264.7 cells stimulated by LPS. Our results revealed that myricetin remarkably ameliorated hepatic steatosis, inflammation, and inhibited hepatic macrophage infiltration in CDAHFD-fed mice. Myricetin-treated to CDAHFD-fed mice also inhibited liver fibrosis and HSC activation when compared with vehicle-treated to those mice. Moreover, myricetin inhibited M1 macrophage polarization and its relative markers in livers of NASH mice while induced M2 polarization. Similarly, in vitro study, myricetin inhibited the LPS-induced mRNA expression of M1 macrophages marker genes and induced IL-4-induced M2 macrophage marker genes in RAW264.7 macrophages. Mechanically, myricetin inhibited the expression of TREM-1 and TLR2/4-MyD88 signaling molecules in livers from NASH mice and in RAW264.7 macrophages stimulated by LPS in vitro. Additionally, myricetin inhibited the activation of nuclear factor (NF)-κB signaling and the phosphorylation of the signal transducer and activation of transcription 3 (STAT3) in LPS-stimulated RAW264.7 macrophages. Taken together, our data indicated that myricetin modulated the polarization of macrophages via inhibiting the TREM-1-TLR2/4-MyD88 signaling molecules in macrophages and therefore mitigated NASH and hepatic fibrosis in the CDAHFD-diet-induced NASH model in mice.

Myricetin Ameliorates Ethanol-Induced Lipid Accumulation in Liver Cells by Reducing Fatty Acid Biosynthesis

SCOPE

Alcoholic liver disease is a serious threat to human health. The development of drug candidates from complementary and alternative medicines is an attractive approach. Myricetin can be found in fruit, vegetables, and herbs. This study investigates the protective effect of myricetin on ethanol-induced injury in mouse liver cells.

METHODS AND RESULTS

Oil-red O staining, assays of oxidative stress and measurements of inflammatory markers in mouse AML12 liver cells collectively demonstrate that myricetin elicits a curative effect on ethanol-induced injury. Next, the role of myricetin in the metabolic regulation of ethanol pathology in liver cells is assessed by gas chromatography coupled with mass spectrometry. Myricetin inhibits ethanol-stimulated fatty acid biosynthesis. Additionally, dodecanoic acid may be proposed as a potential biomarker related to ethanol pathology or myricetin therapy. It is also observed that myricetin enhances ethanol-induced inhibition of the mitochondrial electron transport chain. Moreover, fumaric acid is found to be a candidate biomarker related to ethanol toxicity or myricetin therapy. Quantitative reverse-transcription-PCR shows that ethanol-induced fatty acid synthase and sterol regulatory element-binding protein-1c mRNA levels are alleviated by myricetin. Finally, myricetin increases ethanol-induced inhibition of phosphorylation of AMP-activated protein kinase.

CONCLUSION

These results elucidate the pharmacological mechanism of myricetin on ethanol-induced lipid accumulation.

Artemisia sphaerocephala Krasch polysaccharide prevents hepatic steatosis in high fructose-fed mice associated with changes in the gut microbiota

High fructose (HF) diet-induced liver steatosis is associated with intestinal microbiota dysbiosis.

Hovenia dulcis Extract Attenuates High-Fat Diet-Induced Hepatic Lipid Accumulation and Hypertriglyceridemia in C57BL/6 Mice

The effects of dietary supplementation with aqueous Hovenia dulcis Thunb. extract (HDE) (20 weeks) on high-fat diet (HFD)-induced nonalcoholic fatty liver disease and dyslipidemia were evaluated in mice. Supplementation with 200 and 800 mg/kg feed HDE (HDE200 and HDE800, respectively) resulted in no significant difference in growth in the HFD-fed groups. The triglyceride (TG) levels and free fatty acids were significantly decreased, whereas high-density lipoprotein cholesterol was increased in the HDE800 group (P < .05). The hepatic intracellular TGs were significantly decreased in the HDE-fed groups and lipogenic enzymes (acetyl CoA carboxylase, fatty acid synthase, stearoyl CoA desaturase, and diacylglycerol transferase) in the liver were significantly downregulated by HDE supplementation (P < .05). The diminished serum antioxidant enzyme activities in the HFD group were effectively restored by HDE supplementation, which also contributed to the attenuation of hyperlipidemia.

Postgenomic Properties of Natural Micronutrients

Modern medical approaches to the therapy of various diseases, including cancer, are based on the use of toxic drugs. The unfavorable side effects of traditional medicine could be counterbalanced by addition of natural bioactive substances to conventional therapy due to their mild action on cells combined with the multitargeted effects. To elucidate the real mechanisms of their biological activity, versatile approaches including a number of "omics" such as genomics, transcriptomics, proteomics, and metabolomics are used. This review highlights inclusion of bioactive natural compounds into the therapy of chronic diseases from the viewpoint of modern omics-based nutritional biochemistry. The recently accumulated data argue for necessity to employ nutrigenetic and nutrimetabolomic analyses to prevent or diminish the risk of chronic diseases.

Simultaneous determination of bioactive flavonoids of Hoveniae Semen in rat plasma by LC-MS/MS: Application to a comparative pharmacokinetic study

A selective, sensitive and fully validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for the determination of dihydromyricetin, dihydroquercetin, myricetin and quercetin in rat plasma after intragastric administration of Hoveniae Semen total flavonoids. Baicalin was selected as the internal standard. Analytes were extracted from the rat plasma by protein precipitation with acetonitrile and separated on a C18 chromatographic column (Agilent ZORBAX Eclipse Plus, 4.6 mm × 100 mm, 3.5 μm) using the mobile phase containing acetonitrile (A) and 0.1% formic acid-water (B) by gradient elution at 0.5 mL/min flow rate. A tandem mass spectrometer equipped with an electrospray ionization (ESI) source was used to detect analytes. The analytes were measured by multiple reaction monitoring (MRM) in the negative ionization mode. The lower limit of quantification of dihydromyricetin, dihydroquercetin, myricetin and quercetin were 0.70, 8.16, 1.62 and 0.56 ng/mL, respectively. The accuracy, intra-day and inter-day precision and recovery were all satisfactory and the compounds were stable in rat plasma under all tested conditions. The approach was successfully applied to study pharmacokinetic characteristics of the four bioactive flavonoids in plasma after administering Hoveniae Semen total flavonoids intragastrically to rat. Further investigation was carried out to assess pharmacokinetic comparability of the four bioactive flavonoids after intragastric administration of Hoveniae Semen total flavonoids to mixture of flavonoids.

Mechanisms for Zhige oral solution to prevent and treat alcoholic liver disease in rats

AIM

To explore the preventive and therapeutic effects of Zhige oral solution on alcoholic liver disease in rats and the underlying mechanisms.

METHODS

Ninety male SD rats were randomly divided into six groups: a normal group, a model group, a positive control group, and three intervention groups. The normal group was only given distilled water at 1.0 mL per 100 g/d by gavage, and the other groups were given 52% Luzhou Laobaigan 1.0 mL per 100 g/d by gavage. In addition, the intervention groups were also given different doses (low, medium, and high) of Zhige oral solution and the positive control group was given Jiejiuling oral solution. All groups were allowed free access to water, and fed a normal diet. All the rats were killed at the end of the 12^th week. Hematoxylin and eosin (HE) staining was used to observe the structural changes of liver tissue. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides (TG), and total cholesterol (TC) were measured with an automatic biochemical analyzer. Serum levels of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were detected by enzyme-linked immunosorbent assay (ELISA). The contents of TC and TG in the liver were measured by colorimetric assay. The protein expression of cytochrome P450 2E1 (CYP450 2E1) in the liver was detected by Western blot.

RESULTS

Compared with the normal group, the liver index and the levels of ALT, AST, TC, TG, ADH, ALDH, and CYP450 2E1 were significantly altered in all groups except the high-dose group (P < 0.01 or 0.05), with the model group and low-dose group exhibiting the most significant changes (P < 0.01). Varying degrees of fat vacuolation can be seen in the liver in all groups. Compared with the model group, all the tested indicators above showed varying degrees of reversal in the positive control group and the three intervention groups (P < 0.01 or 0.05), and the reverse effect was best in the high-dose group (P < 0.01). The therapeutic effect of the medium-dose group was similar to that of the positive control group (P > 0.05).

CONCLUSION

The anti-alcoholic and liver-protective effects of Zhige oral solution may be related to reversing the activities of ADH, ALDH, and other enzymes, inhibiting free radicals and acetaldehyde production, reducing oxidative stress, and improving lipid metabolism disorder in rats.

Role of thromboxane A2 signaling in endothelium-dependent contractions of arteries

Thromboxane A₂ (TxA₂) plays a very important role in various cardiovascular diseases through its action on platelet aggregation, vasoconstriction, and proliferation. The present article focuses on the role of TxA₂ signaling in endothelium-dependent contractions of arteries. Arachidonic acid (AA) is metabolized by cyclooxygenase (COX) to form the unstable prostaglandin H₂ which is further converted into TxA₂. After being produced by thromboxane synthase (TxAS), TxA₂ ultimately stimulates TxA₂/prostanoid (TP) receptor to induce vasoconstriction. The calcium ionophore A23187, the prostanoid precursor AA, or the muscarinic receptor agonist acetylcholine (ACh) can evoke endothelium-dependent contractions associated with TxA₂. The endothelium-dependent contractions shown in hypertension, diabetes, atherogenesis, and other cardiovascular diseases have been significantly reduced by antagonism of COX, TxAS, or TP receptor. So inhibition of the bioavailability and/or effect of TxA₂ may be promising therapeutic targets to prevent these diseases. Especially some bioactive compounds isolated from medicinal plants will provide new pharmacological approaches to promote vascular health.

Beneficial effects of apple peel polyphenols on vascular endothelial dysfunction and liver injury in high choline-fed mice

This study was designed to investigate the preventive effects of Red Fuji apple peel polyphenolic extract (APP) on vascular endothelial dysfunction and liver injury in mice fed a high choline diet. The mice were fed 3% dietary choline in drinking water for 8 weeks and displayed vascular dysfunction and liver damage (p < 0.01). The administration of APP at 600 and 900 mg per kg bw significantly elevated serum NO, HDL and 6-Keto-PGF1a levels and lowered serum TC, TG, LDL, ET-1 and TXB2 levels in the HC-fed mice. Besides, APP also caused the reduction of AST, ALT activities and MDA, CRP, TNF-α levels, and increased the hepatic GSH-Px and SOD activities of the HC-fed mice. Furthermore, the histopathology of the liver by conventional H&E and oil red O staining confirmed the liver steatosis induced by a choline diet and the hepatoprotective effect of APP. The experiment results indicated that the polyphenolic extract from apple peel might be regarded as a preventive and therapeutic product for the amelioration of HC diet-induced vascular dysfunction and hepatic injury.

Regressive Effect of Myricetin on Hepatic Steatosis in Mice Fed a High-Fat Diet

Myricetin is an effective antioxidant in the treatment of obesity and obesity-related metabolic disorders. The objective of this study was to explore the regressive effect of myricetin on pre-existing hepatic steatosis induced by high-fat diet (HFD). C57BL/6 mice were fed either a standard diet or a HFD for 12 weeks and then half of the mice were treated with myricetin (0.12% in the diet, w/w) while on their respective diets for further 12 weeks. Myricetin treatment significantly alleviated HFD-induced steatosis, decreased hepatic lipid accumulation and thiobarbituric acid reactive substance (TBARS) levels, and increased antioxidative enzyme activities, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities. Microarray analysis of hepatic gene expression profiles showed that myricetin significantly altered the expression profiles of 177 genes which were involved in 12 biological pathways, including the peroxisome proliferator activated receptor (PPAR) signaling pathway and peroxisome. Further research indicated that myricetin elevated hepatic nuclear Nrf2 translocation, increased the protein expression of heme oxygenase-1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1), reduced the protein expression of PPARγ, and normalized the expressions of genes that were involved in peroxisome and the PPAR signaling pathway. Our data indicated that myricetin might represent an effective therapeutic agent to treat HFD-induced hepatic steatosis via activating the Nrf2 pathway and the PPAR signaling pathway.

Evaluation of Total Flavonoids, Myricetin, and Quercetin from Hovenia dulcis Thunb. As Inhibitors of α-Amylase and α-Glucosidase

This study was designed to investigate the inhibition effect and mechanism of total flavonoids, myricetin and quercetin extracted from Hovenia dulcis Thunb. on α-amylase and α-glucosidase in order to explore the potential use of Hovenia flavonoids in alleviating postprandial hyperglycemia. The results demonstrate that total flavonoids, myricetin, and quercetin were effective inhibitors of α-amylase with IC₅₀ values of 32.8, 662 and 770 μg ml^-1, respectively. And all three were effective inhibitors of α-glucosidase with IC₅₀ values of 8, 3 and 32 μg ml^-1, respectively. Enzyme kinetics tests and Lineweaver-Burk results showed the inhibition effects of total flavonoids, myricetin and quercrtin on α-amylase were all reversible and competitive, and the effects on α-glucosidase were all reversible but non-competitive. This study revealed that Hovenia flavonoids, especially myricetin, are effective and promising functional foods in alleviating type 2 diabetes mellitus.

Protective effects of ursolic acid against hepatotoxicity and endothelial dysfunction in mice with chronic high choline diet consumption

This study was designed to investigate the preventive effect of ursolic acid (UA), a plant-based pentacyclic triterpenoid carboxyl acid, against vascular endothelial damage and liver oxidative injury in the mice fed with 3% dietary high choline (HC) water. Mice fed 3% HC water for 8 weeks significantly displayed liver oxidative stress and vascular endothelial dysfunction (p < 0.01). Furthermore, continuous administration of UA at 400 and 800 mg/kg bw in HC-fed mice could significantly inhibit the HC-induced elevation of serum total cholesterol, total triglyceride, low density lipoprotein-cholesterol, endothelin 1 and thromboxane A2 levels as well as alanine aminotransferase and aspartate aminotransferase activities, while the HC-induced decline of serum high density lipoprotein-cholesterol, endothelial nitric oxide synthase, nitric oxide and prostaglandin I2 levels could be markedly elevated following the treatment (p < 0.05, p < 0.01). UA at 400 and 800 mg/kg bw also increased the hepatic total superoxide dismutase and glutathione peroxidase activities and decreased hepatic malonaldehyde and non-esterified fatty acid levels, relative to HC-treated mice (p < 0.05, p < 0.01). Moreover, the conventional haematoxylin and eosin staining observation of the liver and vascular tissues suggested that UA exerted a significant protective role against HC diet-induced endothelial damage and liver injury in mice. This is the first report showing high intake of dietary choline can induce liver damage and UA has the potential preventive effect against vascular and liver injury in HC-fed mice.