Green tea extract containing a highly absorbent catechin prevents diet-induced lipid metabolism disorder

Evaluating the effect of green tea intake on cardiovascular diseases: A Mendelian randomization study in European and East Asian populations

Previous research shows that more than 70% of cardiovascular diseases (CVDs) are attributed to modifiable risk factors. Here, we investigated relationship between consumption of green tea in European and East Asian populations and risk of CVDs using Mendelian randomization (MR). Instrumental variables for green tea intake were obtained from genome-wide association studies (GWASs) of 64,949 Europeans and 152,653 East Asians. GWASs for CVDs were derived from UK BioBank and BioBank Japan projects. The main method selected for MR analysis was either the inverse variance weighted (IVW) or Wald ratio, depending on the quantity of single nucleotide polymorphisms. Furthermore, we performed sensitivity analyses to confirm the reliability of the findings. Based on the results of IVW, there is no causal relationship between consumption of green tea and risk of 4 CVDs among Europeans (atrial fibrillation: OR = 1.000, 95% CI: 0.995-1.005, P = .910; heart failure: OR = 1.003, 95% CI: 0.994-1.012, P = .542; ischemic stroke: OR = 1.002, 95% CI: 0.993-1.011, P = .690; coronary artery disease: OR = 1.001, 95% CI: 0.996-1.007, P = .677). Sensitivity analyses and supplementary MR analyses also verify the robustness of the findings. Likewise, there was no correlation between the consumption of green tea and the occurrence of CVDs in East Asians. The consumption of green tea is not associated with a reduced risk of CVDs in populations from Europe and East Asia. This means that those who are trying to reduce their risk of CVDs by drinking more green tea may not benefit from doing so.

Doenjang Ameliorates Diet-Induced Hyperlipidemia and Hepatic Oxidative Damage by Improving Lipid Metabolism, Oxidative Stress, and Inflammation in ICR Mice

Hyperlipidemia, characterized by elevated cholesterol, lipids, and triglycerides in the bloodstream, is linked to hepatic oxidative damage. Doenjang, a traditional Korean condiment made from fermented soybeans, is known for its health benefits, yet its anti-hyperlipidemic effects remain understudied. Our study aimed to assess the hypolipidemic and hepatic protective effects of Doenjang on male ICR mice fed a high-fat cholesterol diet for 8 weeks. Mice were divided into three groups: the normal diet (ND), the high-fat cholesterol diet (HD), and the Doenjang-supplemented HD diet (DS) group. Doenjang supplementation significantly regulated total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol levels compared to the HD group. It also downregulated lipogenic genes, including PPARγ, FAS, and ACC, and positively influenced the cholesterol metabolism-related genes HMGCR and LXR. Moreover, Doenjang intake increased serum glutathione levels, activated oxidative stress defense genes (NRF2, SOD, GPx1, and CAT), positively modulated inflammation genes (NF-kB and IL6) in hepatic tissue, and reduced malondialdehyde levels. Our findings highlight the effectiveness of traditional Doenjang in preventing diet-induced hyperlipidemia and protecting against hepatic oxidative damage.

Bioactivity-boosting strategy based on combination of anti-allergic O-methylated catechin with a Citrus flavanone, hesperetin

Many patients with allergies have anxiety about taking anti-allergic medicines due to their side effects and increased medical expenses. Thus, developing functional foods/agricultural products for allergy prevention is strongly desired. In this study, we revealed that a Citrus flavanone, hesperetin, amplified IgE/antigen-mediated degranulation-inhibitory potency of anti-allergic catechin, (-)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3''Me), in the rat basophilic/mast cell line RBL-2H3. Hesperetin also significantly elevated the activation of acid sphingomyelinase (ASM), essential for eliciting anti-allergic effect of EGCG3''Me through the cell surficial protein, 67-kDa laminin receptor (67LR). Furthermore, oral administration of the highly absorbent hesperidin, α-glucosyl hesperidin, also enhanced the inhibitory potency of EGCG3''Me-rich 'Benifuuki' green tea (Camellia sinensis L.) on passive cutaneous anaphylaxis (PCA) reaction evoked by IgE/antigen in BALB/c mice. These observations indicate that hesperetin amplifies the ability of EGCG3''Me to inhibit the IgE/antigen-mediated degranulation through activating ASM signaling.

Testing the Feasibility and Dietary Impact of Macaroni Fortified with Green Tea and Turmeric Curcumin Extract in Diabetic Rats

Macaroni is a commercially available Italian food product that is popular among consumers around the world. The supplementation of green tea extract (GTE) and turmeric curcumin extract (TCE) in macaroni may serve as promising and beneficial bioactive ingredients. We aimed to produce functional macaroni, assess the degree of consumer satisfaction and study the antidiabetic activity in diabetic rats. In this study, macaroni was fortified with GTE, TCE and a mixture of GTE and TCE ratio of 1:1, w/w (GTE/TCE). The resulting products were then analyzed in terms of their chemical compositions, while the degree of consumer satisfaction was monitored and the hypoglycemic and hypolipidemic effects in streptozotocin (STZ)-rats were investigated. GTE/TCE-M exhibited the strongest antioxidant activity (p < 0.05), while phenolics were most abundant in GTE-M. The overall preference for GTE-M, TCE-M and GTE/TCE-M were within ranges of 4.7-5.1, 5.9-6.7 and 6.2-8.2, respectively, in the nine-point hedonic scale. Consumption of these three preparations of macaroni (30 and 300 mg/kg each) neither decreased nor exacerbated increasing blood glucose levels in diabetic rats, while GTE-M (30 mg/kg) tended to lower increased serum triglyceride and cholesterol levels. In conclusion, GTE/TCE-M containing high amounts of bioactive EGCG and curcumin exerted the strongest degree of antioxidant activity and received the highest level of acceptance. Importantly, consumption of GTE-M tentatively ameliorated serum lipid abnormalities in diabetic STZ-induced rats by inhibiting lipase digestion and lipid absorption. Herein, we are proposing that GTE-fortified macaroni is a functional food that can mitigate certain metabolic syndromes.

Redox and Other Biological Activities of Tea Catechins That May Affect Health: Mechanisms and Unresolved Issues

The beneficial health effects of green tea have been attributed to tea catechins. However, the molecular mechanisms of action, especially those in vivo, remain unclear. This article reviews the redox and other activities of tea catechins, using (-)-epigallocatechin-3-gallate (EGCG), as an example. EGCG is a well-known antioxidant. However, EGCG can be oxidized to generate reactive oxygen species and EGCG quinone. We propose that EGCG quinone can react with Keap-1 to activate Nrf2-regulated cytoprotective enzymes. Tissue levels of catechins are important for their biological activities; a section is devoted to reviewing the biological fates of tea catechins after ingestion. Possible EGCG oxidation in vivo and whether the oligomeric forms are biologically active in animals are discussed. We also review the effects of EGCG on the activities of enzymes, receptors, and other signaling molecules through binding and raise a question about whether the autoxidation of EGCG in vitro may lead to artifacts or misinterpretation in some studies. Finally, we discuss the challenges in the extrapolation of in vitro results to situations in vivo and the translation of laboratory studies to humans.

Methylated (-)-epigallocatechin 3-O-gallate potentiates the effect of split vaccine accompanied with upregulation of Toll-like receptor 5

Split-virus vaccine serves as a major countermeasure against influenza virus, but its effectiveness and protective action are not complete. We previously demonstrated the effect of Benifuuki, a green tea cultivar in Japan, on enhancing the split-virus vaccine-elicited immune response. However, little is known about the detail mechanisms. Here, we show that EGCG3"Me intake significantly potentiated the vaccine-elicited hemagglutination inhibition titer increase. Flow cytometry analysis revealed the increased Toll-like receptor 5 (TLR5) expression after EGCG3"Me treatment in lamina propria dendritic cells (LPDCs) and macrophages, which play crucial roles in the humoral immune system. TLR5 expression correlated with the level of interleukin-6 (IL-6)/C-C chemokine type receptor 5, which are important mediators of the humoral immunity. Taken together, In vivo and ex vivo studies showed that EGCG3"Me potentiated the split-virus vaccine-elicited immune response accompanied with the upregulation of TLR5 in intestine and splenocyte macrophages.

Differential Effects of Green Tea Powders on the Protection of Brown Tsaiya and Kaiya Ducklings against Trichothecene T-2 Toxin Toxicity

Simple Summary

The objective of this study is to examine the effects of T-2 toxin (T-2) and green tea powders (GTP) on growth performance, hematology, and pathology parameters in Brown Tsaiya ducklings (BTDs) and Kaiya ducklings (KDs). T-2 toxin shows a strong and differential toxicity in growth suppression, as well as abnormalities in the hematological and pathological parameters of BTDs and KDs. We found that GTP could potentially prevent T-2-induced poor growth performance and improve some hematological parameters. Moreover, BTDs were more sensitive than KDs in terms of responses to T-2 toxicity and GTP detoxification.

Abstract

A 3-week feeding trial in a 3 × 2 × 2 factorial design was conducted with three concentrations (0, 0.5, and 5 mg/kg) of T-2 toxin (T-2) and two levels (0% and 0.5%) of green tea powder (GTP) supplements used in the diets of female brown Tsaiya ducklings (BTDs) and Kaiya ducklings (KDs), respectively. Breed had a significant effect on the growth performances and the relative weights of organs and carcass. In general, the growth performances of KDs were better than BTDs. The relative weights of organs and carcass of BTDs were typically heavier than those of KDs; however, the breast of KDs was heavier than those of BTDs. Both ducklings received 5 mg/kg of T-2 blended in the diet showed lower feed intake and body weight gain (BWG) in the second and the third week. The diet containing 5 mg/kg of T-2 and 0.5% GTP improved the BWG compared to those fed the diet supplemented with 5 mg/kg of T-2 without GTP in BTDs. Ducklings fed the diet containing 5 mg/kg of T-2 induced hypocalcemia and hypomagnesemia, as well as decreased concentrations of creatine phosphokinase and alkaline phosphatase. The concentrations of blood urea nitrogen (BUN) and glutamate oxaloacetate transaminase (GOT) were increased in KDs and BTDs fed the diet containing 5 mg/kg of T-2 without GTP, respectively. However, duckling diets containing 5 mg/kg of T-2 with 0.5% GTP lowered concentrations of BUN and GOT in the blood plasma of KDs and BTDs, respectively. The diet containing 5 mg/kg of T-2 increased the relative kidney weight but decreased the relative breast weight of ducklings. Enlarged gizzards and reduced relative leg weights were observed in BTDs fed the diets containing 5 mg/kg of T-2. In summary, BTDs are more sensitive than KDs in responding to T-2 toxicity and GTP detoxification. Green tea powder has detoxification ability and could potentially mitigate T-2 toxicity on BWG, BUN, and GOT in ducklings.

Simultaneous determination of eight catechins and four theaflavins in bottled tea by liquid chromatography-tandem mass spectrometry for forensic analysis

Tea, and particularly bottled tea, is widely consumed worldwide and is often encountered at crime scenes in poisoning cases or used in place of urine in drug abuse monitoring. Tea is a rich source of polyphenols, such as catechins and theaflavins, and these compounds are useful for identification of trace quantities of tea samples. However, information on the contents of catechins and theaflavins in bottled tea is limited. In this study, a method was developed for simultaneous analysis of eight catechins and four theaflavins in tea using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The concentrations of these polyphenols were determined in bottled black, oolong, and green teas after a simple pretreatment process by the standard addition method. The developed LC-MS/MS method was rapid and all tested polyphenol compounds were separated within ~14 min. All tea types contained all the catechins, at varying concentrations, but not all the theaflavins were present in all the tea types. This indicates that the theaflavin composition reflects the degree of the fermentation and could be used for discrimination among different types of tea. All the green tea samples contained all eight catechins; however, the concentrations of these compounds varied among the tea samples. Principal component analysis and hierarchical cluster analysis were useful for discrimination of samples. It has been unclear whether the variations of chemical components are useful for forensic discrimination. Our results demonstrate that, in addition to identification of tea varieties, catechins and theaflavins can be used for the discrimination of bottled tea samples.

(-)-Epigallocatechin-3-O-gallate at a high concentration may induce lipolysis via ATP consumption by activation of stress defense mechanisms

Green tea catechins have thus far been demonstrated to have antiobesity effects in a variety of experimental models. However, upstream molecular events triggering those phenomena remain to be identified. In this study, we found that (-)-epigallocatechin-3-O-gallate (EGCG) promoted lipolysis in lipid-loaded Huh7 human hepatoma cells. Notably, EGCG at a high concentration induced both oxidative stress and protein stress (proteo-stress), leading to activation of stress defense mechanisms, such as mRNA expressions of antioxidant and phase-2 detoxifying enzymes, and heat shock proteins. Furthermore, EGCG decreased the level of intracellular ATP, while glucose uptake from culture media was promoted possibly for energy homeostasis. EGCG also upregulated the expression of adipose triglyceride lipase, and activated AMP-activated protein kinase. Collectively, these results suggest that EGCG induces lipolysis to compensate for ATP reduction derived from activation of stress defense systems against its oxidative and proteo-stress properties.

Molecular Determinants of the Cardiometabolic Improvements of Dietary Flavanols Identified by an Integrative Analysis of Nutrigenomic Data from a Systematic Review of Animal Studies

SCOPE

Flavanols are important polyphenols of the human diet with extensive demonstrations of their beneficial effects on cardiometabolic health. They contribute to preserve health acting on a large range of cellular processes. The underlying mechanisms of action of flavanols are not fully understood but involve a nutrigenomic regulation.

METHODS AND RESULTS

To further capture how the intake of dietary flavanols results in the modulation of gene expression, nutrigenomics data in response to dietary flavanols obtained from animal models of cardiometabolic diseases have been collected and submitted to a bioinformatics analysis. This systematic analysis shows that dietary flavanols modulate a large range of genes mainly involved in endocrine function, fatty acid metabolism, and inflammation. Several regulators of the gene expression have been predicted and include transcription factors, miRNAs and epigenetic factors.

CONCLUSION

This review highlights the complex and multilevel action of dietary flavanols contributing to their strong potential to preserve cardiometabolic health. The identification of the potential molecular mediators and of the flavanol metabolites driving the nutrigenomic response in the target organs is still a pending question which the answer will contribute to optimize the beneficial health effects of dietary bioactives.

Eriodictyol-Amplified 67-kDa Laminin Receptor Signaling Potentiates the Antiallergic Effect of O-Methylated Catechin

(-)-Epigallocatechin-3-O-(3-O-methyl) gallate (1, EGCG3″Me), an antiallergic O-methylated catechin, is present in high quantities in the green tea cultivar "Benifuuki" (Camellia sinensis L.). Previous studies have shown that EGCG3″Me inhibited basophil degranulation mediated through the cell-surface 67-kDa laminin receptor (67LR), but the mechanisms are not fully elucidated. This study aimed to investigate the mechanisms underlying the inhibitory effect of EGCG3″Me on IgE/antigen (Ag)-mediated degranulation and the combined effect of EGCG3″Me with eriodictyol (2), a bioactive flavanone. EGCG3″Me inhibited β-hexosaminidase release from the rat basophilic/mast cell line RBL-2H3 stimulated by IgE/Ag and induced acid sphingomyelinase (ASM) activity. This induction was inhibited by anti-67LR antibody treatment. The ASM-specific inhibitor desipramine inhibited EGCG3″Me-induced suppression of degranulation. The soluble guanylate cyclase (sGC) inhibitor NS2028 weakened the potency of EGCG3″Me, and the sGC activator BAY41-2272 suppressed degranulation. The ability of EGCG3″Me to induce ASM activity and inhibit degranulation was amplified by eriodictyol. Furthermore, oral administration of the lemon-peel-derived eriodyctiol-7-O-glucoside (3) potentiated the suppressive effect of EGCG3″Me-rich "Benifuuki" green tea on the IgE/Ag-induced passive cutaneous anaphylaxis (PCA) reaction in BALB/c mice. These results suggest that EGCG3″Me inhibits IgE/Ag-mediated degranulation by inducing the 67LR/sGC/ASM signaling pathway, and eriodictyol amplifies this signaling.

Glucosyl-hesperidin enhances the cyclic guanosine monophosphate-inducing effect of a green tea polyphenol EGCG

Animal and clinical studies have revealed that (-)-epigallocatechin-3-O-gallate (EGCG), one of the major bioactive polyphenols in green tea, showed several pharmacological effects including anti-obesity effect and anti-inflammatory effect. We previously reported that the second messenger cyclic guanosine monophosphate (cGMP) mediates its anti-inflammatory and anti-cancer properties. Here we demonstrated that glucosyl-hesperidin, enhances the cGMP-inducing effects of green tea extract in vivo. Moreover, glucosyl-hesperidin intake potentiated the green tea-elicited upregulation of the anti-inflammatory factor, toll-interacting protein.

Pediococcus pentosaceus PP04 Ameliorates High-Fat Diet-Induced Hyperlipidemia by Regulating Lipid Metabolism in C57BL/6N Mice

In this study, Pediococcus pentococcus PP04 isolated from the Northeast pickled cabbage had good gastrointestinal tolerance and can colonize in the intestine stably. C57BL/6N mice were fed a high-fat diet to build animal models and treated with Pediococcus pentosaceus PP04 to evaluate the antihyperlipidemia effect. After 8 weeks, the indicators of hyperlipidemia, liver injury, and inflammation were measured. The treatment of P. pentosaceus PP04 reduced the gain of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), free fatty acids (FFAs), leptin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipopolysaccharides (LPS), and tumor necrosis factor-α (TNF-α) significantly. The western blotting results suggested P. pentosaceus PP04 ameliorated high-fat diet-induced hyperlipidemia by the AMPK signaling pathway, which stimulated lipolysis via upregulation of PPARα and inhibited lipogenesis by downregulation of SREBP-1c, fatty acid synthase (FAS), and stearoyl-CoA desaturase-1 (SCD1) mainly. Furthermore, P. pentosaceus PP04 improved high-fat diet-induced oxidative stress effectively by triggering the Nrf2/CYP2E1 signaling pathway that enhanced the antioxidant activity including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px).

Src Mediates Epigallocatechin-3-O-Gallate-Elicited Acid Sphingomyelinase Activation

Epigallocatechin-3-O-gallate (EGCG) is one of the major bioactive compounds known to be present in green tea. We previously reported that EGCG shows selective toxicity through activation of the protein kinase B (Akt)/cyclic guanosine monophosphate (cGMP)/acid sphingomyelinase (ASM) axis via targeting its receptor 67-kDa laminin receptor (67LR), which is overexpressed in cancer. However, little is known about upstream mechanisms of EGCG-elicited ASM activation. In this study we show that the proto-oncogene tyrosine-protein kinase Src, also known as c-src, plays a crucial role in the anticancer effect of EGCG. We showed that EGCG elicits phosphorylation of Src at Tyr 416, a crucial phosphorylation site for its activity, and that the pharmacological inhibition of Src impedes the upstream events in EGCG-induced cell death signaling including upregulation of Akt activity, increase in cGMP levels, and activation of ASM. Moreover, focal adhesion kinase (FAK), which is involved in the phosphorylation of Src, is colocalized with 67LR. EGCG treatment enhanced interaction of FAK and 67LR. Consistent with these findings, pharmacological inhibition of FAK significantly neutralized EGCG-induced upregulation of Akt activity and activation of ASM. Taken together, FAK/Src play crucial roles in the upstream signaling of EGCG.

Metabolic Impact of Flavonoids Consumption in Obesity: From Central to Peripheral

The prevention and treatment of obesity is primary based on the follow-up of a healthy lifestyle, which includes a healthy diet with an important presence of bioactive compounds such as polyphenols. For many years, the health benefits of polyphenols have been attributed to their anti-oxidant capacity as free radical scavengers. More recently it has been described that polyphenols activate other cell-signaling pathways that are not related to ROS production but rather involved in metabolic regulation. In this review, we have summarized the current knowledge in this field by focusing on the metabolic effects of flavonoids. Flavonoids are widely distributed in the plant kingdom where they are used for growing and defensing. They are structurally characterized by two benzene rings and a heterocyclic pyrone ring and based on the oxidation and saturation status of the heterocyclic ring flavonoids are grouped in seven different subclasses. The present work is focused on describing the molecular mechanisms underlying the metabolic impact of flavonoids in obesity and obesity-related diseases. We described the effects of each group of flavonoids in liver, white and brown adipose tissue and central nervous system and the metabolic and signaling pathways involved on them.

Dietary supplement of Yunkang 10 green tea and treadmill exercise ameliorate high fat diet induced metabolic syndrome of C57BL/6 J mice

Background

Diet and exercise play important roles in ameliorating metabolic syndrome. Yunkang 10 (Camellia sinensis var. assamica) is a most cultivated tea variety for making tea in the Southwestern China. Currently, there is no report of healthy effects of Yunkang 10 green tea (YKGT) and treadmill exercise (Ex) on high fat diet induced metabolic syndrome (MetS). We aimed to investigate the beneficial effects and molecular mechanism of YKGT and Ex using high fat diet induced MetS of C57BL/6 mice.

Methods

Catechins and caffeine in water extract of YKGT were measured via high performance liquid chromatography (HPLC). 10-week old mice were fed with high fat diet (HFD) for 10 weeks to induce obese mice. Then the obese mice were fed with continuous high fat diet (HFD), HFD with YKGT, HFD with Ex, and HFD with both YKGT and Ex for 8 weeks, respectively. The another group of 10-week old mice fed with low fat diet (LFD) were used as control.

Results

HPLC data revealed that YKGT has abundantly high concentration of epigallocatechin gallate (EGCG) and caffeine compared to Longjing 43 (Camellia sinensis var. sinensis) green tea. YKGT and Ex significantly decreased the level of blood glucose, serum total cholesterol (TC), triglyceride (TG), insulin, and alanine aminotransferase activity (ALT) when compared to HFD group. The fatty liver and hepatic pro-inflammatory gene expression in the YKGT, Ex and YKGT+Ex groups was mitigated significantly compared with HFD group, respectively. The phosphorylation of inhibitor of nuclear factor kappa-B kinase α/β (IKKα/β) and inhibitor of nuclear factor kappa-B α (IkBα) protein in the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) signaling pathway was also decreased in YKGT or YKGT+Ex groups. The combination of YKGT and Ex prevented gene expression for lipid synthesis in the liver tissue, and significantly upregulated mRNA level of glucose transport genes in the skeletal muscles, when compared to the HFD group.

Conclusions

This study demonstrated that YKGT supplement or exercise appeared to reverse preexisting metabolic syndrome, and effectively relieved the fatty liver and hepatic inflammatory response induced by high fat diet. YKGT supplement and treadmill exercise together had better beneficial effects than only one intervention.

Solanum nigrum polyphenols reduce body weight and body fat by affecting adipocyte and lipid metabolism

Obesity, being overweight and deposition of body fat are critically associated with metabolic disorders.

Dietary fermented products using koji mold and sweet potato-shochu distillery by-product promotes hepatic and serum cholesterol levels and modulates gut microbiota in mice fed a high-cholesterol diet

It has been reported that fermented products (FPs) prepared from sweet potato-shochu distillery by-product suppressed weight gain and decreased serum cholesterol levels in mice under normal dietary conditions. Furthermore, from the information gained from the above data regarding health benefits of the FPs, the aim of this study was evaluating the effects of dietary FPs on lipid accumulation and gut microbiota in mice with or without cholesterol-load in the diet. C57BL/6N mice were fed normal (CO) diet, CO with 10% FPs (CO + FPs) diet, cholesterol loaded (HC) diet, or HC with 10% FPs (HC + FPs) diet for 8 weeks. The mice were then euthanized, and blood samples, tissue samples, and feces were collected. The adipose tissue weight and liver triglyceride levels in the HC + FPs diet groups were significantly reduced compared to that in the HC diet groups. However, FPs significantly increased the serum non-high-density lipoprotein cholesterol (HDL-C) levels, the ratio of non-HDL-C to HDL-C and hepatic total cholesterol levels in mice fed cholesterol-loaded diet compared with that of the HC diet group. Since dietary FPs significantly decreased the protein expression levels of cholesterol 7 alpha-hydroxylase 1 in the HC + FPs diet groups, the cholesterol accumulation in FPs group may be explained by insufficient catabolism from cholesterol to bile acid. In addition, the dietary FPs tended to increase Clostridium cluster IV and XIVa, which are butyrate-producing bacteria. Related to the result, n-butyrate was significantly increased in the CO + FPs and the HC + FPs diet groups compared to their respective control groups. These findings suggested that dietary FPs modulated the lipid pool and gut microbiota.

Catechin and caffeine contents in green tea at different harvest periods and their metabolism in miniature swine

The catechin content in green tea leaves varies according to cultivation conditions such as intensity of solar radiation, temperature, and precipitation, and thus, there is ambiguity about the best harvest time for obtaining optimal functional effects. In this study, the Yabukita (ordinary) and Benifuki varieties, which contain methylated catechin, were used to determine the difference in green tea catechins according to harvest times and tea manufacturing processes. Caffeine determination was also carried out to provide information about green tea intake for all age-groups of children and pregnant women. Determining the quantity of each catechin was difficult because of degradation, polymerization, and isomerization that had occurred during heat-drying in the refining process. In addition, the absorption of catechin compounds was tested using miniature swine because of their functional and physiological similarity to humans. Benifuki tea leaves contained epigallocatechin-3-(3"-O-methyl) gallate (EGCg3"Me) instead of epigallocatechin-3-(4"-O-methyl) gallate (EGCg4"Me). However, EGCg4"Me was detected during the entire intake period, but EGCg3"Me was not detected in the blood of miniature swine fed Benifuki tea. It is possible that the position of the methyl group was modified by the pig metabolism. Furthermore, caffeine from both Yabukita and Benifuki tea varieties was found to be easily accumulated in miniature swine. These results suggest that nonrefined September-October picking tea (autumn and winter tea) of the Benifuki variety is preferable over the Yabukita variety for consumption by children and pregnant women owing to its lower caffeine content and higher content of methylated catechin.

Chemistry and Health Effect of Tea Polyphenol (-)-Epigallocatechin 3- O-(3- O-Methyl)gallate

Catechins are major polyphenols in tea and have been related to the health promotion of tea. Recently, a unique O-methylated catechin, (-)-epigallocatechin 3- O-(3- O-methyl)gallate (EGCG3″Me) has been identified in limited green and oolong tea. EGCG3″Me-enriched tea has shown distinct physiological functions in animal models and humans compared to common tea, including antiallergy, antiobesity, the prevention of cardiovascular disease risks, etc. This perspective aims to present current knowledge of EGCG3″Me, including its natural occurrence, chemical synthesis, chemical structure, and bioavailability, as well as the molecular mechanisms underlying its biological activities.

Postprandial glycaemia-lowering effect of a green tea cultivar Sunrouge and cultivar-specific metabolic profiling for determining bioactivity-related ingredients

Although the major green tea catechins can inhibit the activity of carbohydrate-hydrolyzing enzymes, there is a paucity of information describing the potential of other green tea ingredients and numerous green tea cultivars. Herein, we reveled that a green tea cultivar Sunrouge significantly suppressed the postprandial blood glucose level in mice. Unlike the most representative Japanese green tea cultivar, Yabukita, the suppression by Sunrouge was observed clearly during the initial period after oral dosing of starch. Sunrouge also strongly inhibited the carbohydrate-hydrolyzing enzymes α-glucosidase and α-amylase when compared with that of Yabukita and many other cultivars. Liquid chromatography-mass spectrometry (LC-MS)-based metabolic profiling (MP) of 42 Japanese green tea cultivars was performed. Multivariate statistical analysis enabled visualization of the differences among cultivars with respect to their ability to inhibit carbohydrate-hydrolyzing activities. Analysis of metabolites, contributing to the discrimination and prediction of the bioactivity of cultivars, showed that O-methylated catechins, epicatechin-3-O-(3-O-methyl) gallate (ECG3"Me) and epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me), were newly identified α-glucosidase inhibitors. Such ability was also observed in epigallocatechin-3-O-gallate (EGCG), epicatechin-3-O-gallate (ECG), delphinidin-3-O-glucoside and myricetin-3-O-glucoside. The amounts of these compounds in Sunrouge were higher than that in many other cultivars. These results suggest that Sunrouge has high potential for suppressing the elevation of the postprandial blood glucose level, and an MP approach may become a valuable strategy for evaluating the anti-hyperglycemic activity of green tea and for screening its active ingredients.

Saturated fatty acid attenuates anti-obesity effect of green tea

Green tea and its major polyphenol epigallocatechin-3-O-gallate (EGCG) have suppressive effect on dietary obesity. However, it remains unsolved what type of diet on which they exhibit high or low anti-obesity effect. In the present study, we investigated whether anti-obesity effect of green tea differs depending on composition of fats or fatty acids that consist high-fat (HF) diet in mouse model. Green tea extract (GTE) intake dramatically suppressed weight gain and fat accumulation induced by olive oil-based HF diet, whereas the effects on those induced by beef tallow-based HF diet were weak. GTE also effectively suppressed obesity induced by unsaturated fatty acid-enriched HF diet with the stronger effect compared with that induced by saturated fatty acid-enriched HF diet. These differences would be associated with the increasing action of GTE on expression of PPARδ signaling pathway-related genes in the white adipose tissue. Expressions of genes relating to EGCG signaling pathway that is critical for exhibition of physiological effects of EGCG were also associated with the different effects of GTE. Here, we show that anti-obesity effect of GTE differs depending on types of fats or fatty acids that consist HF diet and could be attenuated by saturated fatty acid.

Green Tea Polyphenol EGCG Alleviates Metabolic Abnormality and Fatty Liver by Decreasing Bile Acid and Lipid Absorption in Mice

SCOPE

The tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) has been shown to ameliorate metabolic abnormalities and fatty liver. The present study investigates the mechanisms of actions of EGCG on bile acid homeostasis and lipid metabolism.

METHODS

Male C57BL/6J mice are fed a low-fat diet, a high-fat western-style diet, or a high-fat western-style diet containing 0.32% EGCG. The effects of the treatments on biochemical parameters, gene expression, and lipidomics are analyzed.

RESULTS

EGCG treatment significantly reduces body weight gain, mesenteric fat mass, fasting blood glucose, insulin resistance, serum cholesterol, and severity of fatty liver after treatment for 17 weeks, but most of these effects were less apparent at week 33. At week 17, EGCG treatment significantly elevates the mRNA levels of cholesterol 7α-hydroxylase, HMG-CoA reductase, low-density lipoprotein receptor, and scavenger receptor B1, and partially normalizes the high-fat diet induced lipidomic profile. The intestinal bile acid content is significantly decreased by EGCG, while fecal excretion of bile acids, cholesterol, and total lipids are increased.

CONCLUSION

EGCG decreases bile acid reabsorption, results in lower intestinal bile acid levels, which further decreases the absorption of lipids. These actions contribute to the alleviation of metabolic abnormalities and fatty liver disease caused by the high-fat diet.

Randomized controlled trial of the effects of consumption of 'Yabukita' or 'Benifuuki' encapsulated tea-powder on low-density lipoprotein cholesterol level and body weight

Background: Previous studies have reported controversial results for the association between green tea consumption and low-density lipoprotein (LDL)-cholesterol and body weight. Objective: The objective of this trial was to determine the effects of two kinds of green tea on LDL-cholesterol and body weight. Methods: We randomly assigned 151 participants (98 men, 53 women) aged 30-70 years into three groups: Yabukita green tea group, Benifuuki green tea group, or placebo group. Participants consumed 1.8 g/day of green tea extract powder or placebo for 12 weeks. The primary outcomes were LDL-cholesterol level and body weight, and the secondary outcomes were risk factors for cardiovascular disease. Results: Both Yabukita and Benifuuki green tea significantly lowered LDL-cholesterol. The magnitudes of the lipid-lowering effect of both types of tea were significantly larger than that of placebo. No differences with respect to changes in LDL-cholesterol were observed between the Yabukita and Benifuuki green tea groups. Neither Yabukita nor Benifuuki green tea had any effect on body weight and no difference was observed among groups regarding changes in body weight. Conclusion: Both Yabukita and Benifuuki green tea lowered LDL-cholesterol, and the lipid-lowering effects of these two green teas were not different. Neither tea lowered body weight.

The Combination of Green Tea Extract and Eriodictyol Inhibited High-Fat/High-Sucrose Diet-Induced Cholesterol Upregulation Is Accompanied by Suppression of Cholesterol Synthesis Enzymes

Western diets induce obesity associated with an increased risk of hypercholesterolaemia. Indeed, obesity-induced hypercholesterolaemia is correlated with increased coronary cardiovascular disease (CVD) risk. Male C57BL/6J mice were fed a normal diet, high-fat and high-sucrose diet (HF/HS), HF/HS with green tea extract powder diet (HF/HS+GT), HF/HS with eriodictyol diet (HF/HS+Eri), or HF/HS with green tea extract powder and eriodictyol diet (HF/HS+GT+Eri) for 8 wk. Body weight was lower in the HF/HS+GT+Eri group than in the HF/HS group (-8.3%, p<0.01). The HF/HS diet elicited an upregulation of total cholesterol levels (-63%, p<0.001), and low-density lipoprotein (LDL) levels (-89%, p<0.001) were significantly suppressed by the GT+Eri diet. Conversely, no change (p>0.05) was observed in the HF/HS+GT and HF/HS+Eri groups. The HF/HS diet-induced hepatic mRNA increase in 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) was ameliorated (-73%) by the oral administration of green tea extract and eriodictyol. Moreover, the GT+Eri diet suppressed HF/HS diet-induced upregulation of 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMGCS) (-75%, p<0.05). Furthermore, the LDL receptor (LDLR) levels were higher in the HF/HS+GT+Eri group (+50%, p<0.05) than in the HF/HS group. These results suggest that a combination of green tea and eriodictyol decreases cholesterol levels, particularly LDL levels, accompanied by the suppression of HMGCR and HMGCS levels and upregulation of LDLR levels in the liver.

DNA barcode and identification of the varieties and provenances of Taiwan's domestic and imported made teas using ribosomal internal transcribed spacer 2 sequences

The major aim of made tea identification is to identify the variety and provenance of the tea plant. The present experiment used 113 tea plants [Camellia sinensis (L.) O. Kuntze] housed at the Tea Research and Extension Substation, from which 113 internal transcribed spacer 2 (ITS2) fragments, 104 trnL intron, and 98 trnL-trnF intergenic sequence region DNA sequences were successfully sequenced. The similarity of the ITS2 nucleotide sequences between tea plants housed at the Tea Research and Extension Substation was 0.379–0.994. In this polymerase chain reaction-amplified noncoding region, no varieties possessed identical sequences. Compared with the trnL intron and trnL-trnF intergenic sequence fragments of chloroplast cpDNA, the proportion of ITS2 nucleotide sequence variation was large and is more suitable for establishing a DNA barcode database to identify tea plant varieties. After establishing the database, 30 imported teas and 35 domestic made teas were used in this model system to explore the feasibility of using ITS2 sequences to identify the varieties and provenances of made teas. A phylogenetic tree was constructed using ITS2 sequences with the unweighted pair group method with arithmetic mean, which indicated that the same variety of tea plant is likely to be successfully categorized into one cluster, but contamination from other tea plants was also detected. This result provides molecular evidence that the similarity between important tea varieties in Taiwan remains high. We suggest a direct, wide collection of made tea and original samples of tea plants to establish an ITS2 sequence molecular barcode identification database to identify the varieties and provenances of tea plants. The DNA barcode comparison method can satisfy the need for a rapid, low-cost, frontline differentiation of the large amount of made teas from Taiwan and abroad, and can provide molecular evidence of their varieties and provenances.

Green Tea Polyphenol Epigallocatechin-3-gallate Suppresses Toll-like Receptor 4 Expression via Up-regulation of E3 Ubiquitin-protein Ligase RNF216

Toll-like receptor 4 (TLR4) plays an essential role in innate immunity through inflammatory cytokine induction. Recent studies demonstrated that the abnormal activation of TLR4 has a pivotal role in obesity-induced inflammation, which is associated with several diseases, including hyperinsulinemia, hypertriglyceridemia, and cardiovascular disease. Here we demonstrate that (-)-epigallocatechin-3-O-gallate, a natural agonist of the 67-kDa laminin receptor (67LR), suppressed TLR4 expression through E3 ubiquitin-protein ring finger protein 216 (RNF216) up-regulation. Our data indicate cyclic GMP mediates 67LR agonist-dependent RNF216 up-regulation. Moreover, we show that the highly absorbent 67LR agonist (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3″Me) significantly attenuated TLR4 expression in the adipose tissue. EGCG3″Me completely inhibited the high-fat/high-sucrose (HF/HS)-induced up-regulation of tumor necrosis factor α in adipose tissue and serum monocyte chemoattractant protein-1 increase. Furthermore, this agonist intake prevented HF/HS-induced hyperinsulinemia and hypertriglyceridemia. Taken together, 67LR presents an attractive target for the relief of obesity-induced inflammation.

DNA Microarray-Based Screening and Characterization of Traditional Chinese Medicine

The application of DNA microarray assay (DMA) has entered a new era owing to recent innovations in omics technologies. This review summarizes recent applications of DMA-based gene expression profiling by focusing on the screening and characterizationof traditional Chinese medicine. First, herbs, mushrooms, and dietary plants analyzed by DMA along with their effective components and their biological/physiological effects are summarized and discussed by examining their comprehensive list and a list of representative effective chemicals. Second, the mechanisms of action of traditional Chinese medicine are summarized by examining the genes and pathways responsible for the action, the cell functions involved in the action, and the activities found by DMA (silent estrogens). Third, applications of DMA for traditional Chinese medicine are discussed by examining reported examples and new protocols for its use in quality control. Further innovations in the signaling pathway based evaluation of beneficial effects and the assessment of potential risks of traditional Chinese medicine are expected, just as are observed in other closely related fields, such as the therapeutic, environmental, nutritional, and pharmacological fields.

Green Tea Consumption and the Risk of Liver Cancer: A Meta-Analysis

Green tea is a commonly consumed beverage in Asia and has been suggested to have anticarcinogenic properties. To date, epidemiological evidence of the effect of green tea consumption on liver cancer risk remains ambiguous. The aim of this meta-analysis is to evaluate the association between green tea consumption and the risk of liver cancer. The summary relative risk for the highest consumption (≥5 cups/day) of green tea on liver cancer incidence compared with nondrinkers was 0.62 (95% confidence interval: 0.49-0.79). We also found a trend that the incidence of liver cancer was reduced with the increasing years of green tea intake (significance at >20 yr). A significant dose-response association was found between green tea drinking and liver cancer risk. The downward trend was most obvious when the consumption of green tea increased up to about 4 cups/day. The results showed that the increasing green tea intake may have a preventive effect against liver cancer.

Oligomer formation of a tea polyphenol, EGCG, on its sensing molecule 67 kDa laminin receptor

Green tea polyphenol (−)-epigallocatechin-3-O-gallate (EGCG) has been attributed to the activation of its cell surface sensing receptor 67 kDa laminin receptor (67LR).

Green tea cultivar 'Benifuuki' potentiates split vaccine-induced immunoglobulin A production

Influenza is a widespread disease caused by infection with the influenza virus. Vaccination is considered to be the main countermeasure against influenza. A split vaccine is widely used to avoid severe adverse events, and it induces strong humoral immunity. However, the split vaccine alone cannot elicit mucosal immunity, including IgA production, and its preventative effects are limited. Here, we show that the green tea cultivar 'Benifuuki' extract enhanced the effect of a split vaccine on mucosal immunity. The frequency of IgA⁺ cells was increased in lung and Peyer's patch that received Benifuuki diet. Secretion of hemagglutinin-specific mucosal IgA, which is closely linked to the prevention of viral infection, was significantly increased in the bronchoalveolar lavage fluid of split vaccine-immunized BALB/c mice that were administered green tea Benifuuki extract. Our findings suggest that Benifuuki intake enhanced the effects of the split vaccine on mucosal immunity.

Effect of particle size on antioxidant activity and catechin content of green tea powders

This work evaluated the effect of grinding and sieving process of green tea leaves on particle size distribution and antioxidant activity. Granulometric classes ranging from 20 μm to 500 μm were studied. Hydroalcoholic extracts of green tea powders (GTPs) were analysed for total phenolic, total flavonoid, and catechin contents. The fraction of 100-180 μm ground at 6000 rpm showed the maximum catechin content with 33.5 mg/g dry matter (DM) and, the best antioxidant activity with IC50 values of 0.28 μg/mL and 0.13 μg/mL using DPPH and ABTS radical scavenging assays, respectively. However, antioxidant properties and catechin content decreased for particle of sizes less than 50 μm. Catechin content was higher for those ground at 6000 rpm as compared to at 18,000 rpm. The best grinding conditions and particle size were 6000 rpm and 100-180 μm.

Anti-obesity activity of the water extract of Lactobacillus paracasei subsp. paracasei NTU 101 fermented soy milk products

The anti-obesity activity of the water extract of soy milk fermented with Lactobacillus paracasei subsp. paracasei NTU 101 (W101) was investigated. A high-fat diet (HFD) was used to induce obesity in rats, and the effects of daily W101 feeding (8 weeks) were observed. The rats fed the HFD and supplemented with low-dose W101 (LW101, 15 mg per kg body weight per day) or high-dose W101 (HW101, 150 mg per kg body weight per day) had significantly reduced final body weight in comparison with that of the HFD group. W101 decreased the formation of lipid plaques in the aorta, reduced the adipocyte cross-sectional area and diameter, and reduced the levels of CCAAT/enhancer-binding protein β (C/EBPβ), peroxisome proliferator associated receptor γ (PPARγ), and C/EBPα. Regarding lipogenesis regulation in adipocytes, W101 suppressed heparin-releasable lipoprotein lipase (HR-LPL) in adipose tissues and inhibited lipid absorption, thereby reducing lipogenesis. Lactobacillus paracasei subsp. paracasei NTU 101-fermented soy milk may be used to develop health foods that prevent obesity.

MALDI Mass Spectrometry Imaging for Visualizing In Situ Metabolism of Endogenous Metabolites and Dietary Phytochemicals

Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Mass spectrometry imaging (MSI) enables determination of the distribution of ionizable molecules present in tissue sections of whole-body or single heterogeneous organ samples by direct ionization and detection. This emerging technique is now widely used for in situ label-free molecular imaging of endogenous or exogenous small molecules. MSI allows the simultaneous visualization of many types of molecules including a parent molecule and its metabolites. Thus, MSI has received much attention as a potential tool for pathological analysis, understanding pharmaceutical mechanisms, and biomarker discovery. On the other hand, several issues regarding the technical limitations of MSI are as of yet still unresolved. In this review, we describe the capabilities of the latest matrix-assisted laser desorption/ionization (MALDI)-MSI technology for visualizing in situ metabolism of endogenous metabolites or dietary phytochemicals (food factors), and also discuss the technical problems and new challenges, including MALDI matrix selection and metabolite identification, that need to be addressed for effective and widespread application of MSI in the diverse fields of biological, biomedical, and nutraceutical (food functionality) research.