The In Vivo Antioxidant and Hepatoprotective Actions of Selected Chinese Teas

The association between wet overactive bladder and consumption of tea, coffee, and caffeine: Results from 2005-2018 National Health and Nutrition Examination Survey

BACKGROUND & AIMS

Previous studies have reported an inconsistent relationship between overactive bladder (OAB) and the consumption of tea, coffee, and caffeine. Our study aims to determine these associations in a large and nationally representative adult sample.

METHODS

This cross-sectional study included 15,379 participants from the 2005-2018 US National Health and Nutrition Examination Survey (NHANES) database. The outcome was the risk of wet OAB that was diagnosed when the OAB symptom score was ≥3 with urgent urinary incontinence and excluded other diseases affecting diagnosis. The exposures were the consumption of tea, coffee, and caffeine. Weighted logistic regression models were established to explore these associations by calculating odds ratios (OR) and 95% confidence intervals (CI), as did restricted cubic splines (RCS) used to analyze the nonlinear associations.

RESULT

Of all the participants (n = 15,379), 2207 had wet OAB. Mean [SE] consumption of tea, total coffee, caffeinated coffee, decaffeinated coffee, and caffeine was 233.6 [15.7] g/day, 364.3 [15.5] g/day, 301.6 [14.9] g/day, 62.7 [7.9] g/day, 175.5 [6.6] mg/day in participants with wet OAB, respectively. In the fully adjusted model, compared to those without tea consumption, the high consumption of tea (>481 g/day) was associated with an increased risk of wet OAB (OR: 1.29; 95%CI: 1.01-1.64). Low decaffeinated coffee (0.001-177.6 g/day) had a negative association with the risk (OR: 0.66; 95%CI: 0.49-0.90). In the RCS analysis, tea consumption showed a positive linear association with the risk of wet OAB, and decaffeinated coffee showed a nonlinear relationship with the risk and had a turning point of 78 g/day in the U-shaped curve between 0 and 285 g/day. Besides, total coffee, caffeinated coffee, and caffeine consumption had no significant association with the risk. Interestingly, in the high tea consumption, participants with high total coffee consumption [>527.35 g/day, OR and 95%CI: 2.14(1.16-3.94)] and low caffeine consumption [0.1-74.0 mg/day, OR and 95%CI: 1.50(1.03-2.17)] were positively associated with the risk of wet OAB.

CONCLUSION

High tea consumption was associated with the increased risk of wet OAB, especially intake together with high total coffee and low caffeine consumption, but no significant association with the single consumption of total coffee and caffeine. Low decaffeinated coffee was associated with a decreased risk of wet OAB. It is necessary to control tea intake when managing the liquid intake of wet OAB patients.

Transcriptome and proteomics conjoint analysis reveal anti-alcoholic liver injury effect of Dianhong Black Tea volatile substances

Dianhong Black Tea, a fermented tea containing various bioactive ingredients, has been found to have a significant role in alleviating alcoholic liver injury (ALI). One of its main unique components, Dianhong Black Tea volatile substances (DBTVS), may have potential anti-ALI effects. However, its effects and underlying molecular mechanisms are still unknown. In this study, we aimed to investigate the potential of DBTVS as an anti-ALI agent using alcohol-fed rats. We assessed the effect of DBTVS on ALI by analyzing serum transaminase and lipid levels, as well as conducting hematoxylin-eosin and oil red O staining. Additionally, GC-MS was used to detect the components of DBTVS, while transcriptome, proteomics analysis, Western blot, and molecular docking were employed to uncover the underlying mechanisms. Our results demonstrated that DBTVS significantly reduced serum ALT and AST levels and improved lipid metabolism disorders. Moreover, we identified 14 components in DBTVS, with five of them exhibiting strong binding affinity with key proteins. These findings suggested that DBTVS could be a promising agent for the prevention and treatment of ALI. Its potential therapeutic effects may be attributed to its ability to regulate lipid metabolism through the PPAR signaling pathway.

A systemic review on Liubao tea: A time-honored dark tea with distinctive raw materials, process techniques, chemical profiles, and biological activities

Liubao tea (LBT) is a unique microbial-fermented tea that boasts a long consumption history spanning 1500 years. Through a specific post-fermentation process, LBT crafted from local tea cultivars in Liubao town Guangxi acquires four distinct traits, namely, vibrant redness, thickness, aging aroma, and purity. The intricate transformations that occur during post-fermentation involve oxidation, degradation, methylation, glycosylation, and so forth, laying the substance foundation for the distinctive sensory traits. Additionally, LBT contains multitudinous bioactive compounds, such as ellagic acid, catechins, polysaccharides, and theabrownins, which contributes to the diverse modulation abilities on oxidative stress, metabolic syndromes, organic damage, and microbiota flora. However, research on LBT is currently scattered, and there is an urgent need for a systematical recapitulation of the manufacturing process, the dominant microorganisms during fermentation, the dynamic chemical alterations, the sensory traits, and the underlying health benefits. In this review, current research progresses on the peculiar tea varieties, the traditional and modern process technologies, the substance basis of sensory traits, and the latent bioactivities of LBT were comprehensively summarized. Furthermore, the present challenges and deficiencies that hinder the development of LBT, and the possible orientations and future perspectives were thoroughly discussed. By far, the productivity and quality of LBT remain restricted due to the reliance on labor and experience, as well as the incomplete understanding of the intricate interactions and underlying mechanisms involved in processing, organoleptic quality, and bioactivities. Consequently, further research is urgently warranted to address these gaps.

Theabrownin inhibits obesity and non-alcoholic fatty liver disease in mice via serotonin-related signaling pathways and gut-liver axis

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) with obesity seriously threats public health. Our previous studies showed that dark tea had more potential on regulating lipid metabolism than other teas, and theabrownin (TB) was considered to be a main contributor to the bioactivity of dark tea.

OBJECTIVES

This in vivo study aims to reveal the effects and molecular mechanisms of TB on NAFLD and obesity, and the role of the gut-liver axis is explored.

METHODS

The histopathological examinations, biochemical tests, and nuclear magnetic resonance were applied to evaluate the effects of TB on NAFLD and obesity. The untargeted metabolomics was used to find the key molecule for further exploration of molecular mechanisms. The 16S rRNA gene sequencing was used to assess the changes in gut microbiota. The antibiotic cocktail and fecal microbiota transplant were used to clarify the role of gut microbiota.

RESULTS

TB markedly reduced body weight gain (67.01%), body fat rate (62.81%), and hepatic TG level (51.35%) in the preventive experiment. Especially, TB decreased body weight (32.16%), body fat rate (42.56%), and hepatic TG level (42.86%) in the therapeutic experiment. The mechanisms of action could be the improvement of fatty acid oxidation, lipolysis, and oxidative stress via the regulation of serotonin-related signaling pathways. Also, TB increased the abundance of serotonin-related gut microbiota, such as Akkermansia, Bacteroides and Parabacteroides. Antibiotics-induced gut bacterial dysbiosis disrupted the regulation of TB on serotonin-related signaling pathways in liver, whereas the beneficial regulation of TB on target proteins was regained with the restoration of gut microbiota.

CONCLUSION

We find that TB has markedly preventive and therapeutic effects on NAFLD and obesity by regulating serotonin level and related signaling pathways through gut microbiota. Furthermore, gut microbiota and TB co-contribute to alleviating NAFLD and obesity. TB could be a promising medicine for NAFLD and obesity.

Possible Mechanisms of Dark Tea in Cancer Prevention and Management: A Comprehensive Review

Tea is one of the most popular drinks in the world. Dark tea is a kind of post-fermented tea with unique sensory characteristics that is produced by the special fermentation of microorganisms. It contains many bioactive substances, such as tea polyphenols, theabrownin, tea polysaccharides, etc., which have been reported to be beneficial to human health. This paper reviewed the latest research on dark tea's potential in preventing and managing cancer, and the mechanisms mainly involved anti-oxidation, anti-inflammation, inhibiting cancer cell proliferation, inducing cancer cell apoptosis, inhibiting tumor metastasis, and regulating intestinal flora. The purpose of this review is to accumulate evidence on the anti-cancer effects of dark tea, the corresponding mechanisms and limitations of dark tea for cancer prevention and management, the future prospects, and demanding questions about dark tea's possible contributions as an anti-cancer adjuvant.

Integrated genomics and transcriptomics reveal the extreme heavy metal tolerance and adsorption potentiality of Staphylococcus equorum

In this study, we successfully isolated 11 species of cadmium-tolerant bacterium from Pu-erh rhizosphere soil, of which Staphylococcus equorum PU1 showed the highest cadmium tolerance, with a minimum inhibitory concentration (MIC) value of 500 mg/L. The cadmium removal efficiency of PU1 in 400 mg/L cadmium medium reached 58.7 %. Based on the Nanopore PromethION and Illumina NovaSeq platforms, we successfully obtained the complete PU1 genome with a size of 2,705,540 bp, which encoded 2729 genes. We further detected 82 and 44 indel mutations in the PU1 genome compared with the KS1039 and KM1031 genomes from the database. Transcriptional analysis showed that the expression of 11 genes in PU1 increased with increasing cadmium concentrations (from 0 to 200, then to 400 mg/L), which encoded cadmium resistance, cadmium transport, and mercury resistance genes. In addition, some genes showed differential expression patterns with changes in cadmium concentration, including quinone oxidoreductase-like protein, ferrous iron transport protein, and flavohemoprotein. Gene Ontology (GO) functions, including oxidation reduction process and oxidoreductase activity functions, and KEGG pathways, including glycolysis/gluconeogenesis and biosynthesis of secondary metals, were also considered closely related to the extreme cadmium tolerance of PU1. This study provides novel insight into the cadmium tolerance mechanism of bacteria.

Improvement of obesity by Liupao tea is through the IRS-1/PI3K/AKT/GLUT4 signaling pathway according to network pharmacology and experimental verification

BACKGROUND

Obesity is a state of accumulating excessive body fat, charactering by a high blood lipid and associating with various metabolic diseases. As a kind of dark tea, many studies revealed that long-term drinking Liupao tea (LT) can reduce weight (Liu et al., 2014). However, the anti-obesity mechanism and active ingredients of LT are not known.

METHODS

Liquid chromatography-mass spectrometry (LC-MS) combined with network pharmacology was used to screen the active components and related targets of Liupao tea water extract (LTWE). The key anti-obesity targets and pathways of LTWE were predicted by protein-protein interaction (PPI) networks, and enrichment analyses using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases. Then, the active components selected by high-performance liquid chromatography (HPLC) fingerprinting were used together with LTWE in an adipogenic model and insulin resistance (IR) model in vitro.

RESULTS

Most of the compounds identified from LTWE were flavonofids, esters, and amides. Key targets such as RAC-alpha serine/threonine-protein kinase, insulin, and tumor necrosis factor (TNF) were involved in the phosphatidylinositol-3-kinase-protein kinase B (PI3K-AKT) signaling pathway, pathways in cancer, and other pathways. Four active components were screened by network pharmacology combined with HPLC fingerprinting. The in vitro experiment of LTWE and its four active components showed that in insulin-resistant 3T3-L1 cells, LTWE, (-)-epigallocatechin gallate (EGCG) and gallic acid (GA) inhibited adipocyte differentiation. Three factors could inhibit the differentiation of 3T3-L1 cells by decreasing gene expression of peroxisome proliferators-activated receptor γ (PPARγ), fatty acid synthase (FAS), CCAAT/enhancer binding proteins-α (C/EBPα) and interleukin-6 (IL-6). Caffeine and ellagic acid (EA) showed opposite results, but their effects on promoting adipose differentiation diminished with increasing concentrations of drug. In dexamethasone-induced insulin-resistant 3T3-L1 cells, the fluorescence intensity of 2-Deoxy-2-[(7-nitro-2,1,3-Benzoxadiazol-4-yl)amino]-d-glucose revealed that LTWE, GA, EGCG, caffeine, and EA significantly promoted glucose consumption. LTWE, GA, and EA improved insulin resistance in adipocytes by upregulating gene expression of insulin receptor substrate-1 (IRS-1), PI3K, AKT, and glucose transporter 4 (GLUT4).

CONCLUSION

LC-MS combined with network pharmacology preliminarianized that LTWE acts mainly on the PI3K-AKT signaling pathway. Cell experiments revealed that the anti-obesity effect of LTWE is the result of multi-component action, which inhibits the proliferation and differentiation of preadipocytes by regulating gene expression of adipogenic transcription factors and proinflammatory factors, and improves IR by activating the IRS-1/PI3K/AKT/GLUT4 pathway.

Green Tea Catechins Attenuate Neurodegenerative Diseases and Cognitive Deficits

Neurodegenerative diseases exert an overwhelming socioeconomic burden all around the globe. They are mainly characterized by modified protein accumulation that might trigger various biological responses, including oxidative stress, inflammation, regulation of signaling pathways, and excitotoxicity. These disorders have been widely studied during the last decade in the hopes of developing symptom-oriented therapeutics. However, no definitive cure has yet been discovered. Tea is one of the world's most popular beverages. The same plant, Camellia Sinensis (L.).O. Kuntze, is used to make green, black, and oolong teas. Green tea has been most thoroughly studied because of its anti-cancer, anti-obesity, antidiabetic, anti-inflammatory, and neuroprotective properties. The beneficial effect of consumption of tea on neurodegenerative disorders has been reported in several human interventional and observational studies. The polyphenolic compounds found in green tea, known as catechins, have been demonstrated to have many therapeutic effects. They can help in preventing and, somehow, treating neurodegenerative diseases. Catechins show anti-inflammatory as well as antioxidant effects via blocking cytokines' excessive production and inflammatory pathways, as well as chelating metal ions and free radical scavenging. They may inhibit tau protein phosphorylation, amyloid beta aggregation, and release of apoptotic proteins. They can also lower alpha-synuclein levels and boost dopamine levels. All these factors have the potential to affect neurodegenerative disorders. This review will examine catechins' neuroprotective effects by highlighting their biological, pharmacological, antioxidant, and metal chelation abilities, with a focus on their ability to activate diverse cellular pathways in the brain. This review also points out the mechanisms of catechins in various neurodegenerative and cognitive diseases, including Alzheimer's, Parkinson's, multiple sclerosis, and cognitive deficit.

Cordyceps guangdongensis lipid-lowering formula alleviates fat and lipid accumulation by modulating gut microbiota and short-chain fatty acids in high-fat diet mice

Obesity has caused serious health and economic problems in the world. Cordyceps guangdongensis is a high-value macrofungus with broad application potential in the food and bio-medicine industry. This current study aimed to estimate the role of C. guangdongensis lipid-lowering compound formula (CGLC) in regulating fat and lipid accumulation, gut microbiota balance, short-chain fatty acid (SCFA) contents, and expression levels of genes involved in fat and lipid metabolism in high-fat diet (HFD) mice. The results showed that CGLC intervention markedly reduced body weights and fat accumulation in HFD mice, improved glucose tolerance and blood lipid levels, and decreased lipid droplet accumulation and fat vacuole levels in the liver. CGLC decreased the ratio of Firmicutes and Bacteroidetes and increased the relative abundances of Bacteroides (B. acidifaciens) and Bifidobacterium (B. pseudolongum). In addition, CGLC treatment significantly promoted the production of SCFAs and regulated the relative expression levels of genes involved in fat and lipid metabolism in liver. Association analysis showed that several species of Bacteroides and most of SCFAs were significantly associated with serum lipid indicators. These results suggested that CGLC is a novel candidate formulation for treating obesity and non-alcohol fatty liver by regulating gut microbiota, SCFAs, and genes involved in fat and lipid metabolism.

Preventive Effects of Different Black and Dark Teas on Obesity and Non-Alcoholic Fatty Liver Disease and Modulate Gut Microbiota in High-Fat Diet Fed Mice

Non-alcoholic fatty liver disease (NAFLD) has emerged as a leading public health challenge and is closely associated with metabolic syndromes, such as obesity. Intestinal microbiota dysbiosis could play a vital role in the pathogenesis and progression of NAFLD. Tea is the second most popular health drink in the world behind water, and exhibits many health-promoting effects. In this study, the protective effects of different black and dark teas on NAFLD induced by long-term high-fat diet (HFD) exposure and their regulation of gut microbiota were evaluated and explored. The results indicated that supplementation with different black and dark tea extracts could significantly suppress the energy intake, alleviate abnormal accumulation of visceral fat, and prevent obesity, hepatic abnormal lipid deposition and liver steatosis in HFD-fed mice at varying degrees. In addition, Dianhong tea and Liupao tea interventions could significantly decrease the ratio of Firmicutes to Bacteroidetes, and selenium-enriched black tea and selenium-enriched dark rea supplementation could remarkably reduce the relative abundance of Actinobacteria compared to the model group. Moreover, these teas could partly shift the relative abundances of Allobaculum, Roseburia and Dubosiella. Taken together, black teas and dark teas could prevent HFD-induced features of obesity and NAFLD, which might partly be due to the modulation of gut microbiota.

Gut Microbiota Differentially Mediated by Qingmao Tea and Qingzhuan Tea Alleviated High-Fat-Induced Obesity and Associated Metabolic Disorders: The Impact of Microbial Fermentation

Although dark tea is a unique microbial-fermented tea with a high reputation for having an antiobesity effect, little is known about the effect of microbial fermentation on tea leaves’ antiobesity properties. This study compared the antiobesity effects of microbial-fermented Qingzhuan tea (QZT) and unfermented Qingmao tea (QMT), providing insight into their underlying mechanisms associated with gut microbiota. Our results indicated that the supplementation of QMT extract (QMTe) and QZT extract (QZTe) displayed similar antiobesity effects in high-fat diet (HFD)-fed mice, but the hypolipidemic effect of QZTe was significantly stronger than that of QMTe. The microbiomic analysis indicated that QZTe was more effective than QMTe at regulating HFD-caused gut microbiota dysbiosis. Akkermansiaceae and Bifidobacteriaceae, which have negative correlations with obesity, were enhanced notably by QZTe, whereas Faecalibaculum and Erysipelotrichaceae, which are positively correlated with obesity, were decreased dramatically by QMTe and QZTe. A Tax4Fun analysis of QMTe/QZTe-mediated gut microbiota revealed that QMTe supplementation drastically reversed the HFD-induced upregulation of glycolysis and energy metabolism, whereas QZTe supplementation significantly restored the HFD-caused downregulation of pyruvate metabolism. Our findings suggested that microbial fermentation showed a limited effect on tea leaves’ antiobesity, but enhanced their hypolipidemic activity, and QZT could attenuate obesity and associated metabolic disorders by favorably modulating gut microbiota.

Fu brick tea alleviates alcoholic liver injury by modulating the gut microbiota-liver axis and inhibiting the hepatic TLR4/NF-κB signaling pathway

This study first evaluated the protective effects of Fu brick tea water extracts (FTE) on alcoholic liver injury and its underlying mechanism in C57BL/6J mice. Oral administration of FTE by oral gavage (400 mg per kg bw) for 12 weeks significantly alleviated lipid metabolism disorder, reduced the activities of serum ALT and AST, decreased the expression of the liver CYP2E1 gene, and enhanced the antioxidant capacities of the livers in alcohol-fed mice (p < 0.05). FTE also relieved alcohol-induced gut microbiota dysbiosis by promoting the proliferation of probiotics such as Muribaculaceae and Lactobacillus, and subsequently increased the cecal levels of short-chain fatty acids (SCFAs) and decreased the tryptophan content of alcohol-fed mice (p < 0.05). Importantly, FTE was found to improve the alcohol-impaired gut barrier function by up-regulating the expression of the epithelial tight junction protein. Accordingly, FTE decreased the circulating lipopolysaccharide (LPS) and thus inhibited the hepatic TLR4/NF-κB signaling pathway to ameliorate alcoholic liver injury. Cumulatively, these findings shed light on the important role of the gut microbiota-liver axis behind the protective efficacy of FTE on alcoholic liver injury.

Health functions and related molecular mechanisms of ellagitannin-derived urolithins

Ellagitannins are vital bioactive polyphenols that are widely distributed in a variety of plant-based foods. The main metabolites of ellagitannins are urolithins, and current research suggests that urolithins provide a variety of health benefits. This review focused on the role of the gut bacteria in the conversion of ellagitannins to urolithins. Based on the results of in vitro and in vivo studies, the health benefits of urolithins, including antioxidant, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, anti-aging, cardiovascular protective, neuroprotective, kidney protective, and muscle mass protective effects, were thoroughly outlined, with a focus on their associated molecular mechanisms. Finally, we briefly commented on urolithins' safety. Overall, urolithins' diverse health benefits indicate the potential utilization of ellagitannins and urolithins in the creation of functional foods and nutraceuticals to treat and prevent some chronic diseases.

Effects of Different Green Teas on Obesity and Non-Alcoholic Fatty Liver Disease Induced by a High-Fat Diet in Mice

Non-alcoholic fatty liver disease (NAFLD) and obesity are serious public health problems. Green tea is widely consumed in the world and different green teas could possess different bioactivities. In this study, the effects of 10 selected green teas on obesity and NAFLD were evaluated and compared. The mice fed with a high-fat diet were intervened with green tea extract (200 mg/kg body weight) for 15 weeks. Most of these teas were first evaluated for their effects on obesity and NAFLD. The results showed that Selenium-Enriched Chaoqing Green Tea and Jieyang Chaoqing Tea showed the most prominent inhibition of obesity and body weight gains of mice in these two tea intervention groups and model groups were 5.3, 5.5, and 13.7 g, respectively. In addition, Jieyang Chaoqing Tea, Taiping Houkui Tea, and Selenium-Enriched Chaoqing Green Tea exerted the most notable effect on NAFLD, which was attributed to decreasing body weight, and lipid content and ameliorating oxidative stress. Furthermore, 13 phytochemicals were determined in these teas by high-performance liquid chromatography and the correlation analysis found that epigallocatechin gallate, gallocatechin, and epigallocatechin might contribute to the decrease of hepatic weight, while epicatechin might reduce oxidative stress. In general, several green teas could prevent the development of obesity and NAFLD and could be developed into functional foods. This study was also helpful for the public to select appropriate tea to prevent obesity and NAFLD.

Six Types of Tea Reduce Acute Alcoholism in Mice by Enhancing Ethanol Metabolism, Suppressing Oxidative Stress and Inflammation

Acute alcoholic intoxication (AAI) is a pathological process of multiple system damage caused by a large amount of alcohol, especially in the liver. Although tea extracts alleviate AAI and alcohol-induced liver damage, the mechanisms underlying the protective actions of different types of Chinese tea are unclear. In this study, the AAI mice model was used to explore the functions and mechanisms of six types of tea extract (WEATs) in alleviating AAI. The losing righting reflexes of mice were evaluated to assess the effects of the WEATs on AAI. The levels of the ethanol metabolism enzymes (ADH, ALDH2, CYP2E1), the oxidative stress-related indicators (NRF-2, HO-1, SOD, GSH, CAT, and TG) and the inflammatory factors (TNF-α, iNOS, IL-6, and IL-10) were determined. Black tea and dark tea significantly shortened the sleep time (duration of the loss of righting reflex) and had a good sobering effect. Green tea and oolong tea had the dual effect of prolonging tolerance time (time of losing righting reflex) and shortening sleep time. While white tea had the most significant effect on prolonging tolerance time but with no obvious sobering effect. Black tea, dark tea, and oolong tea significantly up-regulated ADH and ALDH2, and down-regulated CYP2E1. Green tea and white tea significantly increased the levels of Nrf2, GSH, and CAT. Black tea, dark tea and oolong tea markedly increased the levels of HO-1, IL-10, and inhibited TG. Therefore, it is possible that black tea, dark tea and oolong tea reduced AAI by increasing ethanol metabolism, suppressing oxidative stress and inflammation. While green tea was mainly by regulating oxidative stress. White tea may prolong the tolerance time by increasing ethanol metabolism and reducing oxidative stress. Different types of tea have specific chemical compositions and can alleviate AAI. In conclusion, despite variations in the composition and mechanism of action, tea is a potent natural product to alleviate a hangover and protect the liver.

Comparison of the Fungal Community, Chemical Composition, Antioxidant Activity, and Taste Characteristics of Fu Brick Tea in Different Regions of China

In this study, the fungal community structure, metabolites, antioxidant ability, and taste characteristics of five Fu brick tea (FBT) from different regions of China were determined and compared. A total of 69 operational taxonomic units (OTUs) were identified and assigned into 5 phyla and 27 genera, with Eurotium as the predominant genus in all samples. Hunan (HN) sample had the strongest fungal diversity and richness, followed by Guangxi (GX) sample, and Zhejiang (ZJ) sample had the lowest. GX sample had higher amounts of gallic acid (GA), total catechins, gallocatechin (GC), and epicatechin gallate (ECG) as well as antioxidant activity than the other samples. The levels of total phenolics, total flavonoids, epigallocatechin (EGC), catechin, epicatechin (EC), thearubigins (TRs), and theaflavins (TFs) were the highest in the ZJ sample. Guizhou (GZ) and Shaanxi (SX) samples contained the highest contents of epigallocatechin gallate (EGCG) and gallocatechin gallate (GCG), respectively. Total phenolics, GA, EC, CG, and TFs were positively associated with most of fungal genera. Total phenolic content (TPC), total flavonoid content (TFC), and most of catechins contributed to the antioxidant activities of FBT. HN sample had the strongest sourness and sweetness, ZJ sample had the strongest saltiness, SX sample had the strongest umami, and GZ sample had the strongest astringency, which was ascribed to the varied metabolites. This work reveals that FBT in different regions vary greatly in fungal community, metabolites, antioxidant activity, and taste characteristics, and provides new insight into the quality characteristics formation of FBT in different regions.

Dietary sources, health benefits, and risks of caffeine

Dietary intake of caffeine has significantly increased in recent years, and beneficial and harmful effects of caffeine have been extensively studied. This paper reviews antioxidant and anti-inflammatory activities of caffeine as well as its protective effects on cardiovascular diseases, obesity, diabetes mellitus, cancers, and neurodegenerative and liver diseases. In addition, we summarize the side effects of long-term or excessive caffeine consumption on sleep, migraine, intraocular pressure, pregnant women, children, and adolescents. The health benefits of caffeine depend on the amount of caffeine intake and the physical condition of consumers. Moderate intake of caffeine helps to prevent and modulate several diseases. However, the long-term or over-consumption of caffeine can lead to addiction, insomnia, migraine, and other side effects. In addition, children, adolescents, pregnant women, and people who are sensitive to caffeine should be recommended to restrict/reduce their intake to avoid potential adverse effects.

The chemistry, processing, and preclinical anti-hyperuricemia potential of tea: a comprehensive review

Hyperuricemia is an abnormal purine metabolic disease that occurs when there is an excess of uric acid in the blood, associated with cardiovascular diseases, hypertension, gout, and renal disease. Dietary intervention is one of the most promising strategies for preventing hyperuricemia and controlling uric acid concentrations. Tea (Camellia sinensis) is known as one of the most common beverages and the source of dietary polyphenols. However, the effect of tea on hyperuricemia is unclear. Recent evidence shows that a lower risk of hyperuricemia is associated with tea intake. To better understand the anti-hyperuricemia effect of tea, this review first briefly describes the pathogenesis of hyperuricemia and the processing techniques of different types of tea. Next, the epidemiological and experimental studies of tea and its bioactive compounds on hyperuricemia in recent years were reviewed. Particular attention was paid to the anti-hyperuricemia mechanisms targeting the hepatic uric acid synthase, renal uric acid transporters, and intestinal microbiota. Additionally, the desirable intake of tea for preventing hyperuricemia is provided. Understanding the anti-hyperuricemia effect and mechanisms of tea can better utilize it as a preventive dietary strategy.HighlightsHigh purine diet, excessive alcohol/fructose consumption, and less exercise/sleep are the induction factors of hyperuricemia.Tea and tea compounds showed alleviated effects for hyperuricemia, especially polyphenols.Tea (containing caffeine or not) is not associated with a higher risk of hyperuricemia.Xanthine oxidase inhibition (reduce uric acid production), Nrf2 activation, and urate transporters regulation (increase uric acid excretion) are the potential molecular targets of anti-hyperuricemic effect of tea.About 5 g tea intake per day may be beneficial for hyperuricemia prevention.

Instant Dark Tea Alleviates Hyperlipidaemia in High-Fat Diet-Fed Rat: From Molecular Evidence to Redox Balance and Beyond

Instant dark tea (IDT) is a new product gaining increasing attention because it is convenient and can endow significant health benefit to consumers, which is partially attributed to its high concentration of functional ingredients. However, the molecular mechanism underlying its regulatory effect on hyperlipidaemia is rarely studied. In this study, we performed omics and molecular verification in high-fat diet (HFD)-fed rat, aiming to reveal the mechanism and provide molecular evidence. The results showed that the major bioactive components in IDT were include 237.9 mg/g total polysaccharides, 336.6 mg/g total polyphenols, and 46.9 mg/g EGCG. Rats fed with IDT (0.27–0.54 g/kg for 12 weeks) significantly reduced the body weight and TC, TG, LDL-C, blood glucose, and MDA and induced the level of serum HDL-C and also the levels of liver SOD, CAT, GSH-Px, and Nrf2, compared to HFD group. For molecular mechanism study, HIDT feeding had significant impact on the gene expressions of biomarkers in lipogenesis (FABP, CD36, SCD1, Cyp4a1, and Kcnn2), lipid oxidation (PPARγ), and glucose glycolysis (Gck and ENO2) in liver tissue. Moreover, gut microbiome study found that rats fed with IDT dramatically modified the gut microbial species at the family level, such as suppressing the increase abundance of Proteobacteria and Firmicutes induced by HFD. HIDT significantly boosted the relative composition of beneficial bacterium Akkermansia and Rikenellaceae_RC9_gut_group and decreased the relative abundance of the harmful bacterium Ruminococcaceae_UCG-005 and Ruminiclostridium_9, compared to HFD (p &lt; 0.01). Correlation analysis between microbiome and animal indicators found that seven genera including Akkermansia, Clostridiales, Lachnospiraceae, Lachnospiraceae_UCG-010, Ruminiclostridium_9, Ruminococaceae-UCG-005, and Ruminocuccus_1 were found as potential biomarkers that were strongly correlated with oxidative stress and metabolism genes. For instance, Ruminococcaceae_UCG-005 was significantly correlated with body weight, TG, HDL-C, Nfr2, FABP3, SCD1, Cyp4a1, and Kcnn2. Collectively, the above data obtained in this study had provided the primary molecular evidence for the molecular mechanism and brought in novel insights based on omics for the regulatory effect of IDT on hyperlipidaemia.

Impact of prolonged withering on phenolic compounds and antioxidant capability in white tea using LC-MS-based metabolomics and HPLC analysis: Comparison with green tea

Contents of 20 bioactive compounds in 12 teas produced in Xinyang Region were determined by high performance liquid chromatography. Ultra-high performance liquid chromatography-quadrupole time of flight-mass spectrometry was developed for untargeted metabolomics analysis. Antioxidant activities were measured by 4 various assays. Those teas could be completely divided into green and white tea through principal component analysis, hierarchical cluster analysis and orthonormal partial least squares-discriminant analysis (R²Y = 0.996 and Q² = 0.982, respectively). The prolonged withering generated 472 differentiated metabolites between white and green tea, prompted significant decreases (variable importance in the projection > 1.0, p-value < 0.05 and fold change > 1.50) of most catechins and 8 phenolic acids to form 4 theaflavins, and benefited for the accumulation of 17 flavonoids and flavonoid glycosides, 8 flavanone and their derivatives, 20 free amino acids, 12 sugars and 1 purine alkaloid. Additionally, kaempferol and taxifolin contributed to 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability of white tea.

Effects of Different Green Tea Extracts on Chronic Alcohol Induced-Fatty Liver Disease by Ameliorating Oxidative Stress and Inflammation in Mice

Alcoholic fatty liver disease (AFLD) is a common chronic liver disease and has become a critical global public health problem. Green tea is a popular drink worldwide and contains several bioactive compounds. Different green teas could contain diverse compounds and possess distinct bioactivities. In the present study, the effects of 10 green teas on chronic alcohol induced-fatty liver disease in mice were explored and compared. The results showed that several green teas significantly reduced triacylglycerol levels in serum and liver as well as the aminotransferase activities in mice at a dose of 200 mg/kg, suggesting that they possess hepatoprotective effects. Moreover, several green teas remarkably decreased the expression of cytochrome P450 2E1, the levels of malondialdehyde and 4-hydroxynonenoic acid, and the contents of proinflammatory cytokines, indicating that they could alleviate oxidation damage and inflammation induced by chronic alcohol exposure. In addition, Seven Star Matcha Tea and Selenium-Enriched Matcha Tea could increase glutathione level. Furthermore, the main phytochemical components in green teas were determined and quantified by high-performance liquid chromatography, and the correlation analysis showed that gallic acid, gallocatechin, catechin, chlorogenic acid, and epigallocatechin gallate might at least partially contribute to protective effects on AFLD. In conclusion, Selenium-Enriched Chaoqing Green Tea, Xihu Longjing Tea, Taiping Houkui Tea, and Selenium-Enriched Matcha Tea showed the strongest preventive effects on AFLD. This research also provides the public with new insights about the effects of different green teas on AFLD.

Processing, chemical signature and food industry applications of Camellia sinensis teas: An overview

The plant Camellia sinensis is the source of different teas (white, green, yellow, oolong, black, and pu-ehr) consumed worldwide, which are classified by the oxidation degree of their bioactive compounds. The sensory (taste, aroma, and body of the drink) and functional properties of teas are affected by the amount of methylxanthines (caffeine and theobromine), amino acids (l-theanine) and reducing sugars in their composition. Additionally, flavan-3-ols, mainly characterized by epicatechins, catechins, and their derivatives, represent on average, 60% of the bioactive compounds in teas. These secondary metabolites from teas are widely recognized for their antioxidant, anti-cancer, and anti-inflammatory properties. Thus, Camellia sinensis extracts and their isolated compounds have been increasingly used by the food industry. However, bioactive compounds are very susceptible to the oxidation caused by processing and degradation under physiological conditions of gastrointestinal digestion. In this context, new approaches/technologies have been developed for the preservation of these compounds. This review presents the main stages involved in production of Camellia sinensis teas following a description of their main bioactive compounds, biological properties, stability and bioaccessibility. Besides, and updated view of Camellia sinensis teas in the field of food science and technology was provided by focusing on novel findings and innovations published in scientific literature over the last five years.

A critical review of Fuzhuan brick tea: processing, chemical constituents, health benefits and potential risk

Fuzhuan brick tea (FBT) is a traditional popular beverage in the border regions of China. Nowadays, FBT has been attracted great attention due to its uniquely flavor and various health-promoting functions. An increasing number of efforts have been devoted to the studies on health benefits and chemistry of FBT over the last decades. However, FBT was still received much less attention than green tea, oolong tea and black tea. Therefore, it is necessary to review the current encouraging findings about processing, microorganisms, chemical constituents, health benefits and potential risk of FBT. The fungus fermentation is the key stage for processing of FBT, which is involved in a complex and unique microbial fermentation process. The fungal community in FBT is mainly dominated by "golden flower" fungi, which is identified as Aspergillus cristatus. A great diversity of novel compounds is formed and identified after a series of biochemical reactions during the fermentation process of FBT. FBT shows various biological activities, such as antioxidant, anti-inflammatory, anti-obesity, anti-bacterial, and anti-tumor activities. Furthermore, the potential risk of FBT was also discussed. It is expected that this review could be useful for stimulating further research of FBT.

Potential role of green tea extract and epigallocatechin gallate in preventing bisphenol A-induced metabolic disorders in rats: Biochemical and molecular evidence

BACKGROUND

Bisphenol A (BPA) is an artificial chemical widely used in the production of polycarbonate plastics and epoxy resins. Accumulating evidence indicates that BPA exposure is associated with metabolic disorders. The beneficial effects of green tea and epigallocatechin gallate (EGCG), major catechin present in green tea, on alleviating BPA-induced metabolic disorders have been shown in various studies.

PURPOSE

Protective effects of green tea extract and EGCG on BPA-induced metabolic disorders and possible underlying mechanisms were investigated.

METHODS

Rats were randomly divided into control, green tea extract (50 and 100 mg/kg, IP), EGCG (20 and 40 mg/kg, IP), BPA (10 mg/kg, gavage), BPA plus green tea extract (25, 50, and 100 mg/kg, IP), BPA plus EGCG (10, 20, and 40 mg/kg, IP), and BPA plus vitamin E (200 IU/kg, IP). After two months, body weight, blood pressure, biochemical blood tests, hepatic malondialdehyde (MDA), and glutathione (GSH) were assessed. By enzyme-linked immunosorbent assay, serum levels of insulin, leptin, adiponectin, TNFα, and IL-6, and by western blotting, hepatic insulin signaling (IRS-1, PI3K, Akt) were measured.

RESULTS

BPA increased body weight, blood pressure, and MDA, decreased GSH, elevated serum levels of low-density lipoprotein cholesterol, total cholesterol, triglyceride, glucose, insulin, leptin, TNFα, IL-6, and liver enzymes including alanine aminotransferase and alkaline phosphatase, and lowered high-density lipoprotein cholesterol and adiponectin levels. In western blot, decreased phosphorylation of IRS-1, PI3K, and Akt was obtained. Administration of green tea extract, EGCG, or vitamin E with BPA reduced the detrimental effects of BPA.

CONCLUSION

These findings indicate that green tea extract and EGCG can be effective in preventing or reducing metabolic disorders induced by BPA linked to their antioxidant and anti-inflammatory activity, regulating the metabolism of lipids, and improving insulin signaling pathways.

Protective effects of tea extracts against alcoholic fatty liver disease in mice via modulating cytochrome P450 2E1 expression and ameliorating oxidative damage

The alcoholic fatty liver disease (AFLD) has been a severe public health problem. Oxidative stress is involved in the initiation and progression of AFLD. Tea is a popular beverage worldwide with strong antioxidant activity. In this research, our purpose is to explore and compare the effects of 12 selected teas on AFLD. The ethanol liquid diet was used to feed the mice, and 12 tea extracts were administrated at 200 mg/kg body weight every day for 4 weeks. The results showed that the application of several tea extracts exhibited different inhibitory effects on lipid accumulation induced by sub-acute alcohol consumption based on the determination of triglyceride concentration and the histological alteration in the liver. In addition, several teas significantly decreased serum alanine aminotransferase and aspartate aminotransferase activities, inhibited the cytochrome P450 2E1 expression, and promoted alcohol metabolism (p < .05). Besides, compared with the model group, several teas obviously elevated superoxide dismutase and glutathione peroxidase activities as well as glutathione content, and remarkably decreased malondialdehyde level (p < .05). In general, Fried Green Tea, Fenghuang Narcissus Oolong Tea, and Pu-erh Dark Tea possessed potential preventive effects on AFLD. Moreover, the main phytochemicals in the three tea extracts were determined and quantified via high-performance liquid chromatography, and the most commonly detected ingredients were catechins and caffeine, which could exert the protective effects on AFLD.

Inhibitory Effects of Six Types of Tea on Aging and High-Fat Diet-Related Amyloid Formation Activities

Aging and lipid metabolism disorders promote the formation and accumulation of amyloid with β-sheet structure, closely related to cardiovascular disease, senile dementia, type 2 diabetes, and other senile degenerative diseases. In this study, five representative teas were selected from each of the six types of tea, and a total of 30 teas were selected to evaluate the inhibitory activities on the formation of aging-related amyloid in vitro. The results showed that the 30 teas had a significant inhibitory effect on the formation activity on aging-related amyloid at the protein level in vitro. Although the content of catechins is relatively low, black tea and dark tea still have significant antioxidant activity and inhibit the formation of amyloid. A high-fat diet established the model of lipid metabolism disorder in premature aging SAMP8 mice, and these mice were gavaged different tea water extracts. The results showed that different tea types have a significant inhibitory effect on the formation of β-amyloid and Aβ42 mediated by age-related lipid metabolism disorders, and the in vivo activity of fully fermented teas was better than that of green tea. The action mechanism was related to antioxidation, anti-inflammatory, and improving lipid metabolism.

Effects and Mechanisms of Probiotics, Prebiotics, Synbiotics, and Postbiotics on Metabolic Diseases Targeting Gut Microbiota: A Narrative Review

Metabolic diseases are serious threats to public health and related to gut microbiota. Probiotics, prebiotics, synbiotics, and postbiotics (PPSP) are powerful regulators of gut microbiota, thus possessing prospects for preventing metabolic diseases. Therefore, the effects and mechanisms of PPSP on metabolic diseases targeting gut microbiota are worth discussing and clarifying. Generally, PPSP benefit metabolic diseases management, especially obesity and type 2 diabetes mellitus. The underlying gut microbial-related mechanisms are mainly the modulation of gut microbiota composition, regulation of gut microbial metabolites, and improvement of intestinal barrier function. Moreover, clinical trials showed the benefits of PPSP on patients with metabolic diseases, while the clinical strategies for gestational diabetes mellitus, optimal formula of synbiotics and health benefits of postbiotics need further study. This review fully summarizes the relationship between probiotics, prebiotics, synbiotics, postbiotics, and metabolic diseases, presents promising results and the one in dispute, and especially attention is paid to illustrates potential mechanisms and clinical effects, which could contribute to the next research and development of PPSP.

Molecular mechanisms underlying health benefits of tea compounds

Tea is one of the three most widely consumed beverages in the world, not only because of its unique flavor but also due to its various health benefits. The bioactive components in tea, such as polyphenols, polysaccharides, polypeptides, pigments, and alkaloids, are the main contributors to its health functions. Based on epidemiological surveys, the consumption of tea and its compounds in daily life has positive effects on cardiovascular diseases, cancers, hepatopathy, obesity, and diabetes mellitus. In experimental studies, the antioxidant, anti-inflammatory, anti-cancer, anti-obesity, cardiovascular protective, liver protective, and hypoglycemic activities of tea and the related mechanisms of action have been widely investigated. The regulation of several classical signaling pathways, such as nuclear factor-κB (NF-κB), AMP activated protein kinase (AMPK), and wingless/integrated (Wnt) signaling, is involved. Clinical trials have also demonstrated the potential of tea products to be applied as dietary supplements and natural medicines. In this paper, we reviewed and discussed the recent literature on the health benefits of tea and its compounds, and specifically explored the molecular mechanisms involved.

Green Tea and Epigallocatechin Gallate (EGCG) for the Management of Nonalcoholic Fatty Liver Diseases (NAFLD): Insights into the Role of Oxidative Stress and Antioxidant Mechanism

Nonalcoholic fatty liver diseases (NAFLD) represent a set of liver disorders progressing from steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma, which induce huge burden to human health. Many pathophysiological factors are considered to influence NAFLD in a parallel pattern, involving insulin resistance, oxidative stress, lipotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, inflammatory cascades, fibrogenic reaction, etc. However, the underlying mechanisms, including those that induce NAFLD development, have not been fully understood. Specifically, oxidative stress, mainly mediated by excessive accumulation of reactive oxygen species, has participated in the multiple NAFLD-related signaling by serving as an accelerator. Ameliorating oxidative stress and maintaining redox homeostasis may be a promising approach for the management of NAFLD. Green tea is one of the most important dietary resources of natural antioxidants, above which epigallocatechin gallate (EGCG) notably contributes to its antioxidative action. Accumulative evidence from randomized clinical trials, systematic reviews, and meta-analysis has revealed the beneficial functions of green tea and EGCG in preventing and managing NAFLD, with acceptable safety in the patients. Abundant animal and cellular studies have demonstrated that green tea and EGCG may protect against NAFLD initiation and development by alleviating oxidative stress and the related metabolism dysfunction, inflammation, fibrosis, and tumorigenesis. The targeted signaling pathways may include, but are not limited to, NRF2, AMPK, SIRT1, NF-κB, TLR4/MYD88, TGF-β/SMAD, and PI3K/Akt/FoxO1, etc. In this review, we thoroughly discuss the oxidative stress-related mechanisms involved in NAFLD development, as well as summarize the protective effects and underlying mechanisms of green tea and EGCG against NAFLD.

Effects of several tea extracts on nonalcoholic fatty liver disease in mice fed with a high-fat diet

Nonalcoholic fatty liver disease (NAFLD) is considered as a severe threat to human health. It has been reported that tea has abundant bioactive compounds and beneficial effects. In our study, the effects of 12 tea extracts on NAFLD were assessed and compared at the dose of 200 mg/kg body weight in mice fed with a high-fat diet (HFD) for 15 weeks. Enshi Yulu Tea, Fenghuang Narcissus Tea, and Yihong Tea showed strong effects in suppressing the accumulation of epididymal and perirenal adipose tissue as well as the increases of body weight and liver weight. The histopathological analysis revealed that hepatic steatosis and adipocyte hypertrophy induced by a HFD could be ameliorated by tea supplementation. In addition, Enshi Yulu Tea and Qing Brick Tea exerted more remarkable functions on decreasing the level of serum triglyceride and preventing hepatic fat accumulation, respectively. Furthermore, Fenghuang Narcissus Tea, Enshi Yulu Tea, and Qing Brick Tea could reverse the abnormal change in the levels of glutathione and superoxide dismutase. Moreover, 13 phytoconstituents were detected and quantified in these teas with high-performance liquid chromatography (HPLC) method. The correlation analysis demonstrated that gallic acid might decrease MDA level, and the reduction of liver weight might be attributed to ellagic acid. However, it should be paid attention to some teas that showed hepatotoxicity with elevated levels of aspartate transaminase and alanine aminotransferase. Several teas showed strong effects in the prevention of NAFLD, which could be developed into functional foods against NAFLD.

Effects of Tea against Alcoholic Fatty Liver Disease by Modulating Gut Microbiota in Chronic Alcohol-Exposed Mice

Gut microbiota dysbiosis has been a crucial contributor to the pathogenesis of alcoholic fatty liver disease (AFLD). Tea is a popular beverage worldwide and exerts antioxidant and anti-inflammatory activities, as well as hepatoprotective effects. However, the potential role of gut microbiota regulated by tea in the prevention and management of AFLD remains unclear. Here, the protective effects of oolong tea, black tea, and dark tea on AFLD and its regulation of gut microbiota in chronic alcohol-exposed mice were explored and investigated. The results revealed that tea supplementation significantly prevented liver steatosis, decreased oxidative stress and inflammation, and modulated gut microbiota in chronic alcohol-exposed mice, especially oolong tea and dark tea. However, black tea showed less effectiveness against liver injury caused by alcohol. Moreover, the diversity, structure and composition of chronic alcohol-disrupted gut microbiota were restored by the supplementation of oolong tea and dark tea based on the analysis of gut microbiota. Furthermore, the relationship between liver injury biochemical indicators and gut microbiota indicated that some specific bacteria, such as Bacteroides, Alloprevotella, and Parabacteroides were closely associated with AFLD. In addition, the phytochemical components in tea extracts were measured by high-performance liquid chromatography, which could contribute to preventive effects on AFLD. In summary, oolong tea and dark tea could prevent chronic alcohol exposure-induced AFLD by modulating gut microbiota.

The Effect of Yellow Tea Leaves Camellia sinensis on the Quality of Stored Chocolate Confectionery

Chocolate and tea leaves are considered the most valuable sources of highly bioactive polyphenols due to their potential anti-cancer properties and beneficial effects on the cardiovascular and nervous systems. The objective of the present study was the development of a sensory profiling modality that is correlated with the taste of the chocolate enriched with yellow tea phytochemicals. The additive concentration was optimized in white chocolate and the designed product was evaluated using the sensory profiling method. It was shown that the yellow tea extract in chocolate had a significant effect on the taste and color of the product. Addition of 2.0% yellow tea powdered extract increased the value of color acceptance and caused an intensification of the aromas, particularly the leafy taste, compared to the control samples. The next step of the study was to determine the influence of tea addition in white, milk and dark chocolate subjected to 6 months of storage. The designed chocolates were tested for their activity as antioxidants (DPPH, ABTS and ORAC assay) and cholinesterase inhibitors (AChE, BChE assay). It was confirmed that the yellow tea addition affected the activity of prepared chocolates with respect to radical scavenging activity and was highest for dark chocolate with yellow tea where the values were as follows: 4373 mg Tx/100 g (DPPH), 386 mg Tx/100 g (ABTS) and 4363 µM Tx/100 g (ORAC). An increase in the anti-radical activity of chocolate with yellow tea was found after 3 months of storage, but the subsequent 3 months of storage resulted in its reduction. AChE values ranged from 0.118 to 0.730 [µM eserine/g dw] and from 0.095 to 0.480 [µM eserine/g dw] for BChE assay. Total capacity to inhibit AChE and BChE differed depending on the type of chocolate and was negatively influenced by the half-year storage. Summarizing tested values for individual samples were higher, with increasing content of cocoa liquor and yellow tea extract in the product. The results of the research show that the use of yellow tea in confectionery is promising and may appoint a new direction in functional foods.

Plant-Based Foods and Their Bioactive Compounds on Fatty Liver Disease: Effects, Mechanisms, and Clinical Application

Fatty liver disease (FLD), including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), is a serious chronic metabolic disease that affects a wide range of people. Lipid accumulation accompanied by oxidative stress and inflammation in the liver is the most important pathogenesis of FLD. The plant-based, high-fiber, and low-fat diet has been recommended to manage FLD for a long time. This review discusses the current state of the art into the effects, mechanisms, and clinical application of plant-based foods in NAFLD and AFLD, with highlighting related molecular mechanisms. Epidemiological evidence revealed that the consumption of several plant-based foods was beneficial to alleviating FLD. Further experimental studies found out that fruits, spices, teas, coffee, and other plants, as well as their bioactive compounds, such as resveratrol, anthocyanin, curcumin, and tea polyphenols, could alleviate FLD by ameliorating hepatic steatosis, oxidative stress, inflammation, gut dysbiosis, and apoptosis, as well as regulating autophagy and ethanol metabolism. More importantly, clinical trials confirmed the beneficial effects of plant-based foods on patients with fatty liver. However, several issues need to be further studied especially the safety and effective doses of plant-based foods and their bioactive compounds. Overall, certain plant-based foods are promising natural sources of bioactive compounds to prevent and alleviate fatty liver disease.

Structural Characterization and Immunostimulatory Activity of Heteropolysaccharides from Fuzhuan Brick Tea

Fuzhuan brick tea (FBT), one of the unique dark teas, has various health-promoting functions. In the present study, one polysaccharide fraction, namely FBTPS-2-1, was extracted and purified from FBT, and its structure and potential immunostimulatory activity were investigated. The results showed that FBTPS-2-1,one of typical heteropolysaccharides, was mainly composed of Gal, Ara, and Glc with little molar content of Man, Rha, GalA, and GlcA in molar ratio of 46.59:22.13:13.57:8.20:6.02:2.12:1.38 and molecular weight of 748 kDa. The backbone of FBTPS-2-1 contained →4)-β-d-Galp-(1→4)-β-d-Galp-(1→, →4)-β-d-Galp-(1→4)-α-d-Glcp-(1→, →4)-α-d-Glcp-(1→4)-α-d-Glcp-(1→, →4)-α-d-Glcp-(1→4)-β-d-Galp-(1→, →3)-β-d-Galp-(1→4)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→3)-β-d-Galp-(1→ and →3,6)-β-d-Galp-(1→3,6)-β-d-Galp-(1→. The linkages of branches in FBTPS-2-1 were mainly composed of α-l-Araf-(1→3,6)-β-d-Galp-(1→, →5)-α-l-Araf-(1→3,6)-β-d-Galp-(1→, →6)-β-d-Galp-(1→3,6)-β-d-Galp-(1→, α-l-Araf-(1→3,5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→5)-α-l-Araf-(1→, α-d-Galp-(1→3,5)-α-l-Araf-(1→ and →5)-α-l-Araf-(1→6)-β-d-Galp-(1→. Furthermore, FBTPS-2-1 could increase the phagocytosis of macrophages and promote the secretion of NO and a variety of inflammatory cytokines, including TNF-α, IL-1β, and IL-6, indicating noticeable immune enhancement activity. Thus, FBTPS-2-1 could serve as a potentially functional food to improve human health by modulating the host immunoreaction.

Antioxidant Food Components for the Prevention and Treatment of Cardiovascular Diseases: Effects, Mechanisms, and Clinical Studies

Cardiovascular diseases (CVDs) have gained increasing attention because of their high prevalence and mortality worldwide. Epidemiological studies revealed that intake of fruits, vegetables, nuts, and cereals could reduce the risk of CVDs, and their antioxidants are considered as the main contributors. Moreover, experimental studies showed that some antioxidant natural products and their bioactive compounds exerted beneficial effects on the cardiovascular system, such as polyphenols, polysaccharides, anthocyanins, epigallocatechin gallate, quercetin, rutin, and puerarin. The mechanisms of action mainly included reducing blood pressure, improving lipid profile, ameliorating oxidative stress, mitigating inflammation, and regulating gut microbiota. Furthermore, clinical trials confirmed the cardiovascular-protective effect of some antioxidant natural products, such as soursop, beetroot, garlic, almond, and green tea. In this review, we summarized the effects of some antioxidant natural products and their bioactive compounds on CVDs based on the epidemiological, experimental, and clinical studies, with special attention paid to the relevant mechanisms and clinical trials.