key: cord-0991967-uhx38ewi
authors: Kochman, Joanna; Jakubczyk, Karolina; Antoniewicz, Justyna; Mruk, Honorata; Janda, Katarzyna
title: Health Benefits and Chemical Composition of Matcha Green Tea: A Review
date: 2020-12-27
journal: Molecules
DOI: 10.3390/molecules26010085
sha: cfce9101ef75772d0441213746367524622e8d57
doc_id: 991967
cord_uid: uhx38ewi

Japanese matcha is a type of powdered green tea, grown in a traditional way. Shading of the plants during the growth period enhances the processes of synthesis and accumulation of biologically active compounds, including theanine, caffeine, chlorophyll and various types of catechins. Green tea contains four main catechins, i.e., (−)-epicatechin (EC), (−)-epicatechin-3-gallate (ECG), (−)-epigallocatechin (EGC) and (−)-epigallocatechin-3-gallate (EGCG), of which the latter is the most active and abundant and matcha is their best condensed source. Due to its unique chemical composition and prized flavour, which sets it apart from other tea beverages, it is considered the highest quality tea. Its health-promoting properties are attributed to the high content of antioxidant and anti-inflammatory substances. Studies confirming the high antioxidant potential of tea beverages claim that it originates from the considerable content of catechins, a type of phenolic compound with beneficial effects on human health. Due to its potential for preventing many diseases and supporting cognitive function, regular consumption of matcha may have a positive effect on both physical and mental health. The aim of this review was to compile the health benefits of matcha tea. It is the first such review to be undertaken, and presents its main bioactive compounds in a systematic manner.

Tea is one of the most consumed beverages, second only to water, in many societies [1] . Its distinctive flavour, aroma and health-promoting effects are highly valued around the world, as are its socio-cultural connotations [2, 3] . Green tea is available in many variants: in the form of loose leaves, packed into teabags or powdered [4] . Matcha is a powdered type of Japanese green tea (Camellia sinensis) of the Tencha variety [5] . The popular beverage has been growing around the world [6] . It is particularly rich in antioxidant compounds as a result of the special cultivation method [7, 8] . According to the traditional method, for the majority of the growth period, the tea bushes are covered using bamboo mats to shade the leaves from excessive direct sunlight [4] . In the course of this process, plants are able to produce higher amounts of amino acids and bioactive compounds, including chlorophyll and theanine, responsible for the unique, non-bitter taste and the characteristic, vibrant colour of matcha. As a result, matcha is highly valued for its quality and regarded as the most aromatic green tea [5, 9] .

The health benefits of green tea arise from the presence of natural antioxidants [10] , such as polyphenols: a wide range of compounds accounting for as much as 30% of the dry weight of green tea [2, 11] . Polyphenols are believed to be exceptionally powerful antioxidants, with effects comparable to those of vitamins, such as vitamins C and E, carotene and tocopherol [12] [13] [14] . The amounts of health-promoting active substances contained in tea beverages depend of the type of tea, the amount of tea leaves per portion, brewing temperature and time [15] .

Studies confirming the high antioxidant potential of tea beverages claim that it originates from the considerable content of catechins, a type of phenolic compound with beneficial effects on human health [1, 10, [16] [17] [18] [19] [20] [21] . Green tea contains four main catechins, i.e., (−)-epicatechin (EC), (−)-epicatechin-3-gallate (ECG), (−)-epigallocatechin (EGC) and (−)-epigallocatechin-3-gallate (EGCG), of which the latter is the most active and abundant [22, 23] . High polyphenolic content has a greater capacity for scavenging free radicals than vitamin C on its own. Phenolic compounds occur naturally in the leaves of Camellia sinensis. Matcha may therefore be described as a major source of catechins in daily human diet [1, 10, 16, 17] .

Epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG) and epicatechin are the main active compounds of the catechin type and are therefore present in the highest amounts in plant products [24] . Catechins derived from tea demonstrate outstanding antioxidant activity due to their ability to neutralise free radicals and boost the detoxification activity of enzymes, including glutathione peroxidase, catalase and glutathione reductase [8, 25] . Grzesik et al. [26] reported that catechins have greater antioxidant capacity than glutathione, vitamin C and flavonoids, which attests to their key role in maintaining cellular redox homeostasis.

According to the study by Koláčková et al. [27] , the total polyphenolic content found in matcha tea falls within the range of 169-273 mg GAE/g. However, Nishitani and Sagesaka [28] observed a lower polyphenol content in matcha than in other green teas. It was then suggested that such a result may be due to the shading of the tea plants, which inhibits polyphenol synthesis. Nevertheless, catechin content in green teas is much higher than in black teas, amounting to 5.46-7.44 mg/g, compared with 0-3.47 mg/g in black tea [29] .

Caffeine is an essential component of tea beverages and is responsible for their distinctive and desirable taste. At the same time, it is a powerful antioxidant adding to the antioxidant potential of the beverage [27] . Its level may be associated with the time of harvest and age of leaves-the older the leaves, the lower the caffeine content. Caffeine content also depends on tea variety, weather conditions during vegetation, as well as the brewing method [27] . The effects of caffeine are rooted in its antioxidant potential, neutralising reactive oxygen species and enhancing antioxidant enzyme activity and total glutathione levels. In regular doses, caffeine may reduce persistent oxidative stress, bringing down the prevalence of free radical-mediated diseases [30] . Additionally, caffeine may inhibit the secretion of proinflammatory cytokines, demonstrating anti-inflammatory effects [31] .

Matcha has a relatively high caffeine content compared to other green teas, which gives it a unique aroma and flavour [29] . The content of caffeine in green teas was found to fall within the range of 11.3-24.67 mg/g [32] , while in matcha it amounted to between 18.9 and 44.4 mg/g [27] . For the sake of comparison, most coffee beans will contain 10.0-12.0 mg caffeine/g of beans [27] .

Phenolic acids are secondary plant metabolites, characterised by high antioxidant and anti-inflammatory potential, in addition to neuroprotective and hypoglycemic effects [30, 33] . They have also been reported to inhibit cancer cell growth and prevent metastasis [34] . Some phenolic acids, through modulating lipid and carbohydrate metabolism, may support the regulation of metabolic disorders [35] . One of the most common compounds from this group found in foodstuffs is chlorogenic acid [27, 35] . In a study by Koláčková et al. [27] , the total content of phenolics in alcoholic extracts was determined to reach up to 273 mg GAE/g. Detailed analysis revealed the following maximum levels of phenolic acids in matcha tea samples, differing in terms of various criteria, including origin: gallic acid-423 µg/g, p-hydroxybenzoic acid-243 µg/g, chlorogenic acid-4800 µg/g, caffeic acid-223 µg/g, ferulic acid-289 µg/g and ellagic acid-371 µg/g [27] .

Rutin, which is a polyphenolic compound, is a potent antioxidant. Its synergistic interaction with ascorbic acid may enhance the protective effects of both substances in the cardiovascular system, strengthening blood vessels [36] . It also has antidiabetic and anti-inflammatory properties, thus preventing diabetes-related pathologies [37, 38] . Its antioxidant and anti-inflammatory action offers potential for preventing conditions of free-radical or inflammatory origin, including neurodegenerative conditions [39] .

According to Jakubczyk et al., [36] matcha green tea has an exceptionally high rutin content, compared to other teas available in the market. The authors contrasted the level of rutin found in matcha (1968.8 mg/L) with that in buckwheat (62.30 mg/100 g), the latter being recognised as one of the richest sources of rutin in the human diet, and demonstrated that matcha tea may be a better source of the compound than other foodstuffs. The findings made by Jakubczyk et al. [36] appear to be consistent with the observations of Koláčková et al. [27] .

Quercetin is a phytochemical with antioxidant and neuroprotective activity [40] [41] [42] . Additionally, it was observed to normalize carbohydrate metabolism by inhibiting glucose absorption from the gastrointestinal tract, regulating insulin secretion and improving insulin sensitivity in tissues [43] . What is more, the combination of quercetin with (−)epigallocatechin gallate (EGCG) may enhance the anticarcinogenic effects of both [6] .

The content of quercetin in the aqueous extract of matcha was measured by Schröder et al. [6] at 1.2 mg/mL, which is marginally higher than in traditional green tea (1.1 mg/mL). On the other hand, Koláčková et al. [27] determined quercetin levels in alcoholic extracts reaching up to 17.2 µg/g.

Vitamin C is a powerful exogenous antioxidant. Due to its properties, it reinforces the immune defence of the body. It is an essential micronutrient in human nutrition which should be supplied every day in adequate amounts [44, 45] .

Jakubczyk et al. [36] demonstrated that infusions of matcha tea contain from 32.12 to 44.8 mg/L of vitamin C, depending on the temperature of water used to prepare the infusion and the type of tea. In the study by Koláčková et al. [27] , matcha was found to contain more than double the amount of vitamin C of other green teas. Its content was determined at 1.63-3.98 mg/g, depending on the type of product and its origin.

Thanks to shade-growing, matcha tea has increased chlorophyll content, which is responsible for its unique vibrant colour [46] . Chlorophyll and its derivatives exhibit strong antioxidant and anti-inflammatory activity [47] .

The levels of bioactive compounds, including chlorophyll, in the Tencha-type tea leaves which are used specifically for matcha were determined by Ku et al. [48] . The level of chlorophyll in Tencha leaves was higher than in traditional green tea, amounting to 5.65 mg/g and 4.33 mg/g, respectively.

Theanine is an amino acid found in the tea plant Camellia sinensis. Due to the shadegrowing of plants intended for matcha production, theanine does not break down. As a result, Tencha leaves contain larger amounts of it compared to other teas [49] . The relatively high theanine content in matcha tea is responsible for its unique non-bitter taste, and in combination with caffeine provides the taste sensation and umami characteristic of this type of tea [48, 50] . The combination of l-theanine and caffeine may enhance concentration, vigilance and efficiency to a higher extent than the use of either compound alone [51] , additionally alleviating stress [49] .

According to Kaneko et al., the content of l-theanine in matcha tea infusions amounts to 6.1 mg/L [50] , while Unno et al. [9] found as much as 44.65 mg/g of that compound in matcha tea samples.

A summary of the health-promoting properties of the main bioactive compounds of matcha green tea is presented in Figure 1 . of chlorophyll in Tencha leaves was higher than in traditional green tea, amounting to 5.65 mg/g and 4.33 mg/g, respectively.

Theanine is an amino acid found in the tea plant Camellia sinensis. Due to the shadegrowing of plants intended for matcha production, theanine does not break down. As a result, Tencha leaves contain larger amounts of it compared to other teas [49] . The relatively high theanine content in matcha tea is responsible for its unique non-bitter taste, and in combination with caffeine provides the taste sensation and umami characteristic of this type of tea [48, 50] . The combination of l-theanine and caffeine may enhance concentration, vigilance and efficiency to a higher extent than the use of either compound alone [51] , additionally alleviating stress [49] .

According to Kaneko et al., the content of l-theanine in matcha tea infusions amounts to 6.1 mg/L [50] , while Unno et al. [9] found as much as 44.65 mg/g of that compound in matcha tea samples.

A summary of the health-promoting properties of the main bioactive compounds of matcha green tea is presented in Figure 1 . 

One parameter which has a significant effect on the chemical composition and healthpromoting properties of a tea beverage is the temperature of the water used to make the infusion. This is related to the extraction of biologically active compounds and higher kinetic energy in tea brewed at a high temperature [2, 36, 52] .

The distinctly high antioxidant potential of matcha can also be attributed to the grinding process and, ultimately, the powdered form. Fujioka et al. [52] demonstrated that infusions made by steeping tea leaves have a lower polyphenol content than those made from the powdered form. Thus, the grinding process itself may accelerate the extraction of polyphenolic compounds. Shishikura and Khokhar [53] observed, taking into account the average time it takes to prepare tea, that its powdered version is more effective and active in terms of the extraction in a relatively shorter time (1 min), and therefore seems to be a better choice. Komes et al. [2] examined 11 green teas differing in terms of the manufacturing process and form, including bagged, loose leaf and powdered tea; matcha brewed at three temperatures-60, 80 and 100 °C; and over different durations, i.e., 3, 5, 

One parameter which has a significant effect on the chemical composition and healthpromoting properties of a tea beverage is the temperature of the water used to make the infusion. This is related to the extraction of biologically active compounds and higher kinetic energy in tea brewed at a high temperature [2, 36, 52] .

The distinctly high antioxidant potential of matcha can also be attributed to the grinding process and, ultimately, the powdered form. Fujioka et al. [52] demonstrated that infusions made by steeping tea leaves have a lower polyphenol content than those made from the powdered form. Thus, the grinding process itself may accelerate the extraction of polyphenolic compounds. Shishikura and Khokhar [53] observed, taking into account the average time it takes to prepare tea, that its powdered version is more effective and active in terms of the extraction in a relatively shorter time (1 min), and therefore seems to be a better choice. Komes et al. [2] examined 11 green teas differing in terms of the manufacturing process and form, including bagged, loose leaf and powdered tea; matcha brewed at three temperatures-60, 80 and 100 • C; and over different durations, i.e., 3, 5, 10, 15 and 30 min. The scholars measured the impact of leaf fragmentation, form of product, brewing time and temperature on phenolic content and antioxidant capacity, determined using different methods (DPPH, FRAP and ABTS). In all green teas, antioxidant capacity increased together with the temperature of water used to prepare the infusion, and the optimal values were observed at the highest temperature with a 3-min brewing time.

It was concluded that the antioxidant potential of green tea increases proportionately to its phenolic content. Additionally, the powdered form had the highest parameters of all the green teas, and the required extraction time was the shortest. Extending the brewing time of powdered matcha did not increase its antioxidant capacity [4] .

The content of health-promoting substances, including polyphenols, is also affected by the agro-climatic conditions during growth, such as the number and distribution of sunny and rainy days, fertilisation and plant protection measures, if any, etc. [54] .

The anticarcinogenic properties of green tea and its key ingredient, (−)-epigallocatechin gallate (EGCG), have been thoroughly researched by scholars from around the globe [40, [55] [56] [57] [58] [59] . The mechanisms behind the anti-cancer effect of EGCG may be related to inhibiting tumour angiogenesis, antioxidant effects and suppressing the inflammatory processes contributing to transformation, hyperproliferation and initiation of carcinogenesis [57, 59] .

The pathogenesis and progression of colorectal cancer is significantly affected by healthy diet and lifestyle. Obesity, especially of the visceral type, as a consequence of long-standing unhealthy lifestyle choices, increases the risk of developing gastrointestinal cancer [60] . Consuming large amounts of EGCG may contribute to reducing the incidence of colorectal cancer, partly due to inhibiting tumour growth factors. What is more, EGCG is capable of inhibiting growth and inducing apoptosis of cancer cells [58] . Improving tissue sensitivity to insulin and leptin, and reducing blood lipid parameters, may inhibit obesity-related carcinogenesis. Supplementation of green tea extracts may additionally prevent recurring adenomas, which in the majority of cases may evolve into colorectal cancers [58] . Research findings regarding EGCG supplementation also include inhibition of growth and proliferation of gallbladder and bile duct cancer cells, as well as a decreased risk of biliary duct cancer [40, 57] .

Catechins act synergistically with anticancer medications, and can be used to support therapy as well as in cancer prevention [61] . Vitamin C has also been associated with protective effects against cancer [62] .

Inflammatory response is part and parcel of many diseases. It may lead to the production of excessive amounts of substances promoting the production of reactive oxygen species (ROS), which can damage cell structures and lead to long-term disruption in the functioning of the body as a whole, as well as playing signalling functions promoting inflammation. The main effect of anti-inflammatory and antioxidant substances is to inhibit signalling in the inflammatory process by scavenging ROS [63] .

Supplementation of EGCG, the main bioactive component of green tea, may alleviate complications of the inflammatory process arising after the use of cardiopulmonary bypass for major cardiac surgery, including lung injury and dysfunction [64, 65] . By regulating the inflammatory condition, EGCG also helps reduce the susceptibility to gallstone formation. Arterial hypertension is controlled by multiple genes, with inflammation and vascular remodelling implicated in the pathogenesis of this condition [66, 67] . Consumption of green tea beverages with a high content of bioactive compounds regulating inflammatory processes attenuates the development of hepatitis, by suppressing gene and protein expression of inflammatory cytokines [22] .

Cigarette smoking is recognised as one of the main risk factors for cardiovascular diseases [68] . In an experiment with an animal model, rats were exposed to cigarette smoke, with simultaneous oral administration of EGCG [69] . Upon exposure to smoking, the markers of myocardial injury and lipid anomalies were elevated. Administration of EGCG reversed these aberrations. The findings from that study suggest that the antioxidant EGCG may exert a protective effect on the heart muscle by preventing cardiac inflammatory changes via reducing oxidative stress [69] . EGCG may potentially exert a protective effect on the heart muscle in patients undergoing surgery who are susceptible to ischemic injury, by inhibiting the activation of stress-activated protein kinase and signalling pathways inducing the inflammatory response [70, 71] .

The immunomodulatory properties of green tea and its antiviral effect may support the prevention and regulate immune response in infectious diseases, including COVID-19 [72, 73] . There are many studies on the antiviral properties of green tea, however they are mostly based on reports about traditional green tea [74] [75] [76] [77] [78] . The mechanism of action and specific properties of matcha green tea are still unknown and equated with general reports on green tea, despite the different composition and ratio of bioactive compounds [2, 4, 36, 56] . However, in one of the few studies, Ohgitani et al. [79] demonstrated that matcha green tea may have antiviral activity (by inactivating SARS-CoV-2), which is a promising report, but requires more detailed research. Documented potential properties and probable mechanism of action of green tea compounds are presented in Table 1 . Table 1 . Research on antiviral properties of green tea compounds.

EGCG Antiviral effect depends on virus type e.g. inhibiting replication of HIV-1, inhibiting viral (HBV) entry to the cell, inhibiting first stages of infection, inactivate SARS-CoV-2, inhibiting SARS-Cov-2 main protease and SARS-CoV-2 3C-like protease, binding to viral surface proteins [78] , [80] , [77] , [81] , [79] , [82] , [83] , [84] Catechins Inhibiting adherention and cell penetration, disruption of the viral replication cycle, inhibiting HCV replication, anti-inflammatory, inhibiting SARS-Cov-2 main protease [85] , [76] , [86] , [87] Quercetin Inhibiting SARS-Cov replication by inhibition of SARS-Cov-3C-like protease [88] Catechins, quercetin Inhibiting COVID-19 main protease and structural proteins [73] 

The effects of catechins and other polyphenolics on the parameters of carbohydrate metabolism show their hypoglycemic action [89] . Matcha may help lower blood glucose levels [90] , and its EGCG content may inhibit starch digestion, thus minimising the sudden release of glucose in the gastrointestinal tract [91] . EGCG may present capacity for inhibiting gluconeogenesis and the absorption of lipids and glucose from the gastrointestinal tract, as well as improving insulin sensitivity [89] .

Consumption of green tea is regarded as an effective dietary intervention to promote clarity of mind and cognitive function. These health benefits are attributed mainly to epigallocatechin gallate (EGCG) [92] .

Cognitive function tends to deteriorate with age in a manner dependant on environmental factors, including lifestyle [93] . Regular dietary intake of caffeine may reduce the risk of cognitive decline in women, and its effect increases with age [94] . By reversing oxidative processes and reducing neuroinflammation, caffeine may indirectly inhibit ageing of the brain [95] , and in this way maintain its normal function. Oxidative stress, which is capable of inducing neuronal damage, may induce memory impairment. Caffeine supplementation, with its anti-inflammatory effects, chiefly in the hippocampus, may prevent the development of this disorder [96] . The positive effects of caffeine on the nervous system and preventing neurodegenerative diseases are closely related to the decreased deposition of amyloid-β in the brain [97] . Systemic inflammation induced by lipopolysaccharide (LPS) plays a key role in neurodegenerative diseases. EGCG inhibits LPS-induced production of reactive oxygen species, suggesting that EGCG is a potent and effective neuroprotective agent in neurological disorders mediated by inflammation [98] .

EGCG intake enhances cognitive function, improves insulin sensitivity and decreases amyloid-β production in the brain, thus reducing neuroinflammation and preventing neuropathologies related to neurodegenerative diseases, including Alzheimer's disease [99] .

Matcha green tea, due to its unique composition of bioactive compounds, offers a wide range of potential health benefits, as presented in Table 2 . It contains high concentrations of phenolic acids, quercetin, rutin, theanine and chlorophyll, exceeding those in other green tea varieties. It is a relatively new and unknown product, which cannot be identified with traditional green tea; it is a separate tea variety with distinct properties. Its infusions and extracts may find potential applications in preventing lifestyle diseases of free-radical and inflammatory origin, as well as in preventing premature ageing processes. Matcha tea, thanks to its powdered form, makes for an easy-to-use food additive. Unfortunately, the direct impact and mechanisms responsible for the properties of matcha tea have not been sufficiently explored. Hence, many of the potential aspects of its activity, e.g., its interactions with intestinal microflora and impact on infectious diseases, requires further study. It seems necessary to carry out more extensive research, including a detailed examination of the chemical composition of matcha tea, studies with the use of cell lines and animal models, and randomised clinical trials (RCT) to confirm the hypothesised beneficial effects of matcha tea on human health. Table 2 . Summary of research on the health-promoting properties of matcha green tea.

The Component Associated with the Effect

Anticarcinogenic effects

Catechins support therapy as well as in cancer prevention, inhibiting tumour growth factors and inducing apoptosis of cancer cells [58] , [61] Vitamin C protective effects against cancer [62] Phenolic acids inhibiting cancer cell growth and prevent metastasis [34] EGCG inhibiting tumour angiogenesis, antioxidant effects and suppressing the inflammatory processes contributing to transformation, hyperproliferation and initiation of carcinogenesis, improving tissue sensitivity to insulin and leptin, and reducing blood lipid parameters; [57] , [58] , [59] , [61] Anti-inflammatory effects EGCG scavenging ROS, regulating the inflammatory condition and response [22] , [66] Cardioprotective EGCG reducing oxidative stress, inhibiting the activation of stress-activated protein kinase and signalling pathways inducing the inflammatory response [69] , [70] Rutin strengthening blood vessels [36] Improvement of cognitive function and prevention of neurodegenerative disorders EGCG promote clarity of mind and cognitive function, inhibits LPS-induced production of reactive oxygen species, improves insulin sensitivity and decreases amyloid-β production in the brain [92] , [98] , [99] Caffeine reduce the risk of cognitive decline, reversing oxidative processes and reducing neuroinflammation, inhibit ageing of the brain, anti-inflammatory effects, decreased deposition of amyloid-β in the brain [94] , [95] , [96] , [97] Regulation of carbohydrate metabolism EGCG inhibiting starch digestion, inhibiting gluconeogenesis and the absorption of lipids and glucose, improving insulin sensitivity [89] , [91] Quercetin inhibiting glucose absorption, regulating insulin secretion, improving insulin sensitivity [43] Phenolic acids modulating lipid and carbohydrate metabolism [35] 

The Japanese powdered green tea, matcha, contains high amounts of substances with antioxidant and anti-inflammatory effects. It has promising potential health benefits, mainly through a high concentration of catechins. With regular consumption, it may support the body's efforts to maintain health and prevent disease. Research into the effects of matcha drinking and its individual components in specific disease entities is still valid and needed. The current state of knowledge only covers some of the healthpromoting properties of this tea. To confirm the validity of implementing recommendations for increased consumption of tea beverages made from matcha, it will be necessary to undertake deeper and broader analyses of its effects on the human body. 

The authors declare no conflict of interest.

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Antioxidant Activity of Different Forms of Green Tea: Loose Leaf, Bagged and Matcha

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Effects of Green Tea, Matcha Tea and Their Components Epigallocatechin Gallate and Quercetin on MCF-7 and MDA-MB-231 Breast Carcinoma Cells

Effect of Shading Intensity on Morphological and Color Traits and on Chemical Components of New Tea (Camellia Sinensis L.) Shoots under Direct Covering Cultivation

Medicinal and Therapeutic Potentialities of Tea

Stress-Reducing Function of Matcha Green Tea in Animal Experiments and

Wpływ Warunków Parzenia Na Zawartość Antyoksydantow w Naparach Różnych Rodzajów Herbat. Wiadomości Chem

Multifunctional Activities of Green Tea Catechins in Neuroprotection. Modulation of Cell Survival Genes, Iron-Dependent Oxidative Stress and PKC Signaling Pathway

A Review of Latest Research Findings on the Health Promotion Properties of Tea

The effect of herbal remedies on the vitality of body

Tea Phenols: Antioxidant Effectiveness of Teas, Tea Components, Tea Fractions and Their Binding with Lipoproteins

Catechin Composition and Antioxidant Activity of Black Teas in Relation to Brewing Time

Total Antioxidant Capacity of Teas by the Ferric Reducing/Antioxidant Power Assay

Tamang Bioactive Compounds and Antioxidant Properties of Tea: Status, Global Research and Potentialities

Micromechanism of Ultrahigh Pressure Extraction of Active Ingredients from Green Tea Leaves

Separation of Major Catechins from Green Tea by Ultrahigh Pressure Extraction

Function of Green Tea Catechins in the Brain: Epigallocatechin Gallate and Its Metabolites

A Review of the Role of Green Tea (Camellia Sinensis) in Antiphotoaging, Stress Resistance, Neuroprotection, and Autophagy

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Green Tea Catechins: Their Use in Treating and Preventing Infectious Diseases

Epigallocatechin Gallate (EGCG) Is the Most Effective Cancer Chemopreventive Polyphenol in Green Tea

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Antioxidant Properties of Catechins: Comparison with Other Antioxidants

Analysis of Nutritional Composition, Phenolics and Antioxidant Activity

Simultaneous Determination of Catechins, Caffeine and Other Phenolic Compounds in Tea Using New HPLC Method

Ahmed, I. Chemical Composition and Sensory Evaluation of Tea (Camellia Sinensis) Commercialized in Pakistan

Caffeine, Chlorogenic Acid, and the Purinergic System

Caffeine-Stimulated Intestinal Epithelial Cells Suppress Lipid Accumulation in Adipocytes

Authenticity Evaluation of Tea-Based Products

Phenolic Acids Derivatives-Biotechnological Methods of Synthesis and Bioactivity

Chemopreventive Effects of Dietary Phytochemicals against Cancer Invasion and Metastasis: Phenolic Acids, Monophenol, Polyphenol, and Their Derivatives

Chlorogenic Acid (CGA): A Pharmacological Review and Call for Further Research

Antioxidant Properties and Nutritional Composition of Matcha Green Tea

Review of the Protective Effects of Rutin on the Metabolic Function as an Important Dietary Flavonoid

Mechanisms of Antidiabetic Effects of Flavonoid Rutin

Rutin as a Natural Therapy for Alzheimer's Disease: Insights into Its Mechanisms of Action

Quercetin and EGCG Exhibit Chemopreventive Effects in Cholangiocarcinoma Cells via Suppression of JAK/STAT Signaling Pathway

Mechanisms of Neuroprotection by Quercetin: Counteracting Oxidative Stress and More

Quercetin in Food: Possible Mechanisms of Its Effect on Memory

The Antidiabetic Potential of Quercetin: Underlying Mechanisms

Vitamin C and Immune Function

Antioxidant Properties of Small-Molecule Non-Enzymatic Compounds

Identification of Chlorophylls and Carotenoids in Major Teas by High-Performance Liquid Chromatography with Photodiode Array Detection

Synthesis, Characterization, and Functional Properties of Chlorophylls, Pheophytins, and Zn-Pheophytins

Metabolomics Analysis Reveals the Compositional Differences of Shade Grown Tea (Camellia Sinensis L.)

Stress-Reducing Effect of Cookies Containing Matcha Green Tea: Essential Ratio among Theanine, Arginine, Caffeine and Epigallocatechin Gallate

Molecular and Sensory Studies on the Umami Taste of Japanese Green Tea

Effect of Green Tea Phytochemicals on Mood and Cognition

The Powdering Process with a Set of Ceramic Mills for Green Tea Promoted Catechin Extraction and the ROS Inhibition Effect

Factors Affecting the Levels of Catechins and Caffeine in Tea Beverage: Estimated Daily Intakes and Antioxidant Activity

Determination of Antioxidant Activity, Rutin, Quercetin, Phenolic Acids and Trace Elements in Tea Infusions: Influence of Citric Acid Addition on Extraction of Metals

Anti-Cancer Properties Epigallocatechin-Gallate Contained in Green Tea

Cancer Prevention with Green Tea and Its Principal Constituent, EGCG: From Early Investigations to Current Focus on Human Cancer Stem Cells

Association between Green Tea/Coffee Consumption and Biliary Tract Cancer: A Population-Based Cohort Study in Japan

Green Tea Extracts for the Prevention of Metachronous Colorectal Adenomas: A Pilot Study

Cancer Prevention by Tea: Animal Studies, Molecular Mechanisms and Human Relevance

The Prediction of Colorectal Cancer Using Anthropometric Measures: A Swedish Population-Based Cohort Study with 22 Years of Follow-Up. United Eur

Synergistic Enhancement of Anticancer Effects on Numerous Human Cancer Cell Lines Treated with the Combination of EGCG, Other Green Tea Catechins, and Anticancer Compounds

Gall Bladder Cancer and the Role of Dietary and Lifestyle Factors: A Case-Control Study in a North Indian Population

Green Tea Extracts Epigallocatechin-3-Gallate for Different Treatments

Dähnert, I. Anti-Oxidative or Anti-Inflammatory Additives Reduce Ischemia/Reperfusions Injury in an Animal Model of Cardiopulmonary Bypass

Epigallocatechin Gallate Attenuates Cardiopulmonary Bypass-Associated Lung Injury

EGCG Reducing the Susceptibility to Cholesterol Gallstone Formation through the Regulation of Inflammation

Induction of Inflammatory Gene Expression by THP-1 Macrophages Cultured in Normocholesterolaemic Hypertensive Sera and Modulatory Effects of Green Tea Polyphenols

Estimates of Global Mortality Attributable to Smoking in 2000

Attenuation of the Cardiac Inflammatory Changes and Lipid Anomalies by (-)-Epigallocatechin-Gallate in Cigarette Smoke-Exposed Rats

Epigallocatechin-3-Gallate, a Green Tea Catechin, Protects the Heart against Regional Ischemia-Reperfusion Injuries through Activation of RISK Survival Pathways in Rats

Mitogen-Activated Protein Kinases in Atherosclerosis

Food as Medicine: A Possible Preventive Measure against Coronavirus Disease (COVID-19)

Potential Inhibitor of COVID-19 Main Protease (Mpro) From Several Medicinal Plant Compounds by Molecular Docking Study

Antiviral Effect of Catechins in Green Tea on Influenza Virus

The Green Tea Molecule EGCG Inhibits Zika Virus Entry

Antiviral Effects of Green Tea (Camellia Sinensis) against Pathogenic Viruses in Human and Animals (a Mini-Review)

A Review of the Antiviral Role of Green Tea Catechins

Antiviral Activity of Green Tea and Black Tea Polyphenols in Prophylaxis and Treatment of COVID-19: A Review

Significant Inactivation of SARS-CoV-2 by a Green Tea Catechin, a Catechin-Derivative and Galloylated Theaflavins in Vitro

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Protective Effect of Epigallocatechin-3-Gallate (EGCG) in Diseases with Uncontrolled Immune Activation: Could Such a Scenario Be Helpful to Counteract COVID-19?

Activity of Catechins and Their Applications

Green Tea Phenolic Epicatechins Inhibit Hepatitis C Virus Replication via Cycloxygenase-2 and Attenuate Virus-Induced Inflammation

Evaluation of Green Tea Polyphenols as Novel Corona Virus (SARS CoV-2) Main Protease (Mpro) Inhibitors -an in Silico Docking and Molecular Dynamics Simulation Study

Flavonoid-Mediated Inhibition of SARS Coronavirus 3C-like Protease Expressed in Pichia Pastoris

Changes in Intestinal Microbiota of Type 2 Diabetes in Mice in Response to Dietary Supplementation With Instant Tea or Matcha. Can

Powdered Green Tea, Ameliorates the Progression of Renal and Hepatic Damage in Type 2 Diabetic OLETF Rats

Effect of Tea Products on the in Vitro Enzymatic Digestibility of Starch

Dietary Supplementation of a High-Temperature-Processed Green Tea Extract Attenuates Cognitive Impairment in PS2 and Tg2576 Mice

The Neuroprotective Effects of Caffeine in Neurodegenerative Diseases

The Neuroprotective Effects of Caffeine: A Prospective Population Study (the Three City Study)

Caffeine Prevents D-Galactose-Induced Cognitive Deficits, Oxidative Stress, Neuroinflammation and Neurodegeneration in the Adult Rat Brain

Caffeine Prevents Memory Impairment Induced by Hyperhomocysteinemia

Caffeine Reverses Cognitive Impairment and Decreases Brain Amyloid-Beta Levels in Aged Alzheimer's Disease Mice

Epigallocatechin Gallate against Lipopolysaccharide-Mediated Cytotoxicity

Epigallocatechin-3-Gallate (EGCG) Improves Cognitive Deficits Aggravated by an Obesogenic Diet Through Modulation of Unfolded Protein Response in APPswe/PS1dE9 Mice