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This research intended the utilization of Javanese turmeric (0.4% w/v) as a kombucha substrate and analysis of its hepatoprotective activity, in comparison against nonfermented Javanese turmeric beverage (JTB) and black tea kombucha.

Forty-two healthy male Balb/c mice (two- to three-week-old, 20–30 g) were divided into six groups with seven replicates each. The treatments were normal diet, normal diet + Javanese turmeric kombucha (JTK), normal diet + diethylnitrosamine (DEN), DEN + JTB, DEN + JTK, DEN + black tea kombucha. Kombuchas and JTB were given at 0.3 mL/20 g BW/d. DEN was induced intraperitoneally at a dose of 100 mg/kg. Observed biomarkers were blood serum glutamate pyruvate transaminase (SGPT) and serum glutamate oxaloacetate transaminase (SGOT) activity, serum malonaldehyde (MDA), as well as liver histology. Data were analyzed using analysis of variance.

Among DEN-induced groups, JTK significantly (p < 0.05) diminished the level of blood SGPT, SGOT and serum MDA. JTK also had lower blood SGPT (8.604 ± 2.195 U/L) and serum MDA levels (2.884 ± 0.083 nM/mL) compared to the normal group (8.604 ± 2.195 U/L and 5.050 ± 0.998 nM/mL, respectively). JTK also produced the least damaged liver-cell numbers.

JTK demonstrated better hepatoprotective activity compared to JTB.

White tea is an unfermented tea made from young shoots of Camellia sinensis protected from sunlight to avoid polyphenol degradation. White tea contains a high level of polyphenolic compounds known as catechins. Several types of evidence have suggested that tea consumption has benefits in body weight and endurance maintenance. This study was designed to evaluate the effect of white tea on body weight and endurance of animal models.

This research was an intervention design using 20 Wistar white rats (Rattus Norvegicus) in body weight between 150 and 200 g. The rats were randomized into four groups, three groups receiving white tea drink (WTD) with different doses and the other group receiving plain water in equal volume as a control group for four weeks. The forced swim test (FST) was done to measure their struggling capacity, and digital bodyweight to measure the weight.

Intervention (WTD Groups and Control) caused weight gain among except G3 with the highest doses of white tea. The result showed that WTD intake in G3 had a significant difference (p < 0.05) on body weight gain compared to control. The authors found that WTD in a specific dose (G3: 0.22 mg) tends to maintain the body weight of animals (219.2 ± 41.96; 212.6 ± 46.90, respectively), while other doses caused weight gain. WTD also significantly increased the swimming and struggling capacity of rats that represented improvements the endurance along with the test. There was a statistically significant difference in endurance among all groups (p < 0.05).

The results of this study can be followed as human intervention research as an input for nutritionists and sports scientists to explore the beneficial effect of white tea.

The results of this study can be followed as human intervention research as an input for nutritionists and sports scientists to explore the beneficial effect of white tea.

This study adds more evidence and information about the advantages of white tea as potential beverages in future healthy lifestyles.

The epigallocatechin gallate (EGCG) effect in diabetes has been investigated in animal studies, but results of clinical trials are inconsistent. Thus, this study aims to evaluate the effects of EGCG supplementation in patients with type 2 diabetes mellitus (T2DM).

A total of 50 patients with T2DM were recruited in a double-blind, randomized, placebo-controlled trial. The eligible participants were randomly allocated to EGCG (n = 25) and placebo (n = 25) groups. The EGCG group received two capsules of EGCG (each capsule contained 150 mg; Shari Made®, Iran) and placebo group was administered two capsules of placebo (starch) for eight weeks. A three-day 24-h dietary recall and anthropometric and laboratory measurements were carried out at the beginning and the end of the study.

At the end of the trial, weight and body mass index (BMI) were decreased significantly in both groups, but the reduction was not statistically significant between the two groups. Fasting blood sugar decreased significantly in EGCG group. No significant between-group and within-group differences were found in insulin, homeostatic model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index values. The high-sensitive C-reactive protein (hs-CRP) was significantly reduced in the EGCG group (4.13 ± 0.48-3.93 ± 0.50, p = 0.003) compared to baseline.

This study showed that consuming 300 mg/day of EGCG for eight weeks in patients with T2DM caused a significant decrease in fasting blood glucose, body weight, BMI and hs-CRP compared to baseline. Therefore, the EGCG supplementation may improve glycemic control, anthropometric and inflammation status in T2DM.

It is argued that COVID-19 patients show various neuropsychiatric symptoms, including fatigue, depression and anxiety. On the other hand, epidemiological and experimental evidence indicated that green tea could potentially have antiviral effects and ameliorate psychiatric disorders. However, there is a lack of clinical evidence. The purpose of this study was to investigate whether drinking green tea can clinically improve psychiatric complications of COVID-19 infection.

This study included 40 patients with laboratory confirmed mild-to-moderate COVID-19 disorder in the current randomized open-label controlled trial. Patients were instructed to include three cups/day of green tea (intervention) or black tea (control) to their usual diet for four weeks immediately after diagnosis of the disease. At the study baseline and after the intervention, the enrolled patients’ fatigue, depression and anxiety were assessed by the Chalder Fatigue Scale, Beck Depression Inventory-Fast Screen and State-Trait Anxiety Inventory questionnaires.

A total of 19 COVID-19 cases in the intervention group (mean age = 52 years) and 14 cases (mean age = 50 years) in the control group completed the study. Analysis of covariance adjusted for baseline levels, and confounders revealed that those who consumed three cups/day of green tea compared to the patients who received black tea experienced significantly lower fatigue, depression and state and trait anxiety levels (adjusted means for fatigue = 12.3 vs 16.2 (P = 0.03), depression = 0.53 vs 1.8 (P = 0.01), 37.4 vs 45.5 (P < 0.01) and 37.9 vs 45.2 (P < 0.01)).

The open-label design may bias the evaluation of the self-reported status of fatigue, depression or anxiety as the main outcomes assessed. Moreover, as this study did not include patients with severe COVID-19, this might affect the generalizability of the present results. Thus, the recommendation of daily drinking green tea may be limited to the subjects diagnosed with mild-to-moderate type of infection or those with long-term neuropsychiatric complications owing to COVID-19. Besides, considering the ethical issues, this study could not exclude the drug therapy’s confounding effects; thereby, this point should be considered when interpreting the current results. Besides, it is worth noting that Guilan province in the north of Iran is recognized as a tea (and particularly green tea) producing region; thereby, it is an available and relatively inexpensive product. Considering this issue, the recommendation to consume this medicinal plant in adjunct to the routine treatment approach among patients with mild-to-moderate COVID-19 based on its beneficial effects may be widely accepted.

Green tea consumption could be considered an option to combat COVID-19 associated psychological complications, including fatigue, depression and anxiety among patients suffering from mild-to-moderate type of this viral infection.

To the best of the authors’ knowledge, in this study, for the first time, the effects of green tea compared to black tea on COVID-19 associated fatigue, depression and anxiety status within an open-label controlled trial have been investigated.

The purpose of the study was to explore the possibility of utilization of epigallocatechin-3-gallate (EGCG) as a novel preservative in cheese. EGCG has strong antioxidant and antimicrobial properties and may be commercially exploited as a natural antioxidant and preservative in cheese like products which are highly susceptible to lipid oxidation.

The study was conducted to evaluate the possibility of using EGCG as a natural antioxidant and preservative in cheese. Kalari, a hard and dry cheese, was used as a model and treated with different concentrations of EGCG (0, 0.05 and 0.10 per cent) and aerobically packaged within low-density polyethylene pouches and assessed for oxidative stability and storage quality under refrigerated (4 ± 1°C) conditions.

EGCG showed a significant (p < 0.05) effect on the lipid oxidative stability as the treated products exhibited significantly (p < 0.05) lower thiobarbituric acid reactive substances (milligram malonaldehyde/kg) values. A significant (p < 0.05) effect was also observed on the microbiological characteristics of the products, as treated products showed significantly (p < 0.05) lower values for total plate count (log cfu/g), psychrophilic count (log cfu/g), yeast and mould count (log cfu/g) and free fatty acid (% oleic acid) values. Coliforms (log cfu/g) were not detected throughout the storage period. Significantly (p < 0.05) higher scores were observed for various sensory parameters of the treated products. EGCG successfully improved the oxidative stability and storage quality of Kalari.

The results suggest that EGCG might be useful to the dairy industry as an efficient alternative to synthetic antioxidants and preservatives.

The purpose of this study is to focus on the preparation of macroporous adsorption resins (MARs) functionalized with carbazole and N-methylimidazole, and adsorption behaviors of (–)-epigallocatechin gallate (EGCG) and caffeine (CAF) on the functionalized MARs.

Based on the Friedel–Crafts and amination reactions, novel MARs functionalized with carbazole and N-methylimidazole were synthesized and characterized by the BET method. Accordingly, adsorption behaviors and structure-activity relationships for EGCG and CAF were studied in detail.

The results showed that pseudosecond-order kinetic model was provided with a better correlation for the adsorption of EGCG and CAF onto L-1 and L-2, and pseudofirst-order kinetic model was the most suitable model to illustrate the adsorption process for EGCG and CAF on L-3. The result indicated that Langmuir, Freundlich, Temkin–Pyzhev and Dubinin–Radushkevich isotherms all could better illustrate the adsorption processes of EGCG and CAF on L-1, L-2 and L-3.

This study provides theoretical guidance and technical support for the efficient separation and purification of EGCG and CAF from waste tea leaves by MARs on a large scale. In addition, the results showed that this novel MARs would provide useful help and be used in large-scale production of active ingredients from natural products in the industry and other fields.

Adsorption kinetic models such as pseudofirst-order, pseudosecond-order and intra-particle diffusion kinetic models, and adsorption isotherm models such as Langmuir, Freundlich, Temkin–Pyzhev and Dubinin–Radushkevich isotherms models were adopted to illustrate the adsorption mechanisms of EGCG and CAF. The main driving forces for MARs with no functional groups were pore sieving effects, p–p conjugation effects and hydrophobic interactions, and the other significant driving forces for MARs functionalized with carbazole and N-methylimidazole were electrostatic interactions, ion-dipole and hydrogen bonding interactions. This study might provide scientific references and useful help for large-scale separating and enriching active ingredients in natural products using the technology of MARs with special functional groups.

The purpose of this paper was to determine total polyphenols (TP), total flavonoids (TF) and (-)-epigallocatechin gallate (EGCG) in five commercial tea extracts and in their infusions at various temperatures (95-60°C) and brewing times (5-30 min).

TP was determined by the Folin–Ciocalteu method, TF by the aluminium chloride colorimetric method and EGCG by HPLC method.

The results showed that White tea – Silver needle had the highest content of TP and EGCG when extracted, but its infusions had very poor concentrations of these compounds. Green tea infusion was better source of TP and EGCG than white or black tea, although its extract did not contain a very high amount of TP compared to the latter two types. Black tea extract had a relatively high content of TP and TF in its extract. Its infusions as well contained higher concentrations of TP than white tea, but lower concentrations of EGCG than all studied teas.

Increasing infusion time and temperature does not necessarily increase the concentration, according to the results. To the authors’ knowledge, this is the first report on comparing these types of tea, especially the white tea, with other well-known teas under various infusion conditions. The extraction of the white tea leaves was also not found in previous works.

Polyphenols possess anti-allergic activities. Catechin is one of the polyphenols that are abundantly present in the Acacia catechu. In this study, the authors investigated the effect of catechin isolated from A. catechu in an experimental mouse model of ovalbumin (OVA)-induced allergic asthma.

Catechin was isolated from A. catechu, and phytochemical analysis was carried out by ultraviolet visible and thin-layer chromatography (TLC), high pressure thin-layer chromatography was used for the determination of an amount of catechin present. In a first set of an experiment, the authors have carried out dose-dependent evaluation of catechin on histamine synthesis in normal rats. In another study, allergic asthma was induced in BALB/c mice by intraperitoneal injection of 50 mg OVA dissolved in 4 mg aluminum hydroxide dissolved in 0.2 ml saline on Days 0 and 14. Catechin was given orally at the dose of 100 mg/kg, once a day from Day 1 to Day 35 and after which various respiratory parameters such as tidal volume, respiratory rate and airflow rate, biochemical parameters such as histamine release from mast cells, bronchoalveolar (BAL) lavage fluid analysis and histopathology of lungs were carried out.

Catechin showed significant (p < 0.05) improvement in respiratory parameters such as tidal volume, respiratory rate and airflow rate, as well as biochemical and hematological parameters such as blood histamine, serum bicarbonate and nitric oxide levels as compared to the disease control group. The treatment also showed inhibitory effects on histamine synthesis in rat peritoneal as well as BAL mast cells. Also, a significant (p < 0.05) improvement in lung histopathology was observed with catechin.

From the present study, the authors can conclude that catechin exhibited potent anti-allergic activity by inhibition of histamine synthesis by inhibition of histidine decarboxylase enzyme. The study suggests that catechin has therapeutic potential for the treatment of allergic inflammatory disease in humans.

Tea contains high content of phenolics which are well-known to act as antioxidants. As such, there are claims that the consumption of infusion of tea could help ameliorate free radical-induced diseases; this therapeutic activity would depend on the amount of phenolics that is soluble and the amount that is absorbed and available for metabolic activity when consumed. The purpose of this study is to analyze the content of phenolics and antioxidant activity of some health tea and also to study the effect of addition of sugar and milk on in-vitro availability of phenolics in tea, cocoa and coffee drinks.

Seven brands of health tea, two brands of cocoa drink, one brand each of coffee, powdered milk and sugar were selected. The tea samples were analyzed for pH, titratable acidity, total phenol and antioxidant activity using Folin–Ciocalteau and 202-diphenyl-1-picryl-hydrazil 28DPPH-29-20 reagents. In-vitro simulated digestion modeling stomach and small intestine were carried out on tea infusion, coffee and cocoa drinks with or without sugar, and phenolic availability was analyzed.

The result indicated that pH, titratable acidity and total phenolics ranged from 4.5 to 5.6, 0.167 to 0.837 (as maleic acid) and 1.15 to 1.17 mg/g gallic acid equivalent, respectively. Black tea recorded the highest phenolic content, in-vitro phenolic availability and antioxidant activity. Addition of sugar to black tea and chocolate drink caused a significant decrease in the in-vitro available phenolics, while the addition of milk leads to a significant enhancement.

The data obtained in this study can be used nutritionally and commercially to show the impact of adding sugar or milk on the content of phenolics and their bioavailability in-vitro. The study justifies the claim that tea could help ameliorate free radical-induced health defects.

Assessment of antioxidant activity of food should not be based only on the content of total phenolics but on the amount that is bioavailable in the body system when the food is consumed.

Consumption of tea, cocoa and coffee drinks with milk and sugar have been found to enhance or inhibit phenolics. Therefore, the optimum level of these additives should be determined if the drinks were meant for therapeutic purposes.

Results obtained may provide some useful information for considering the bioavailability of phenolics present in tea and beverages in view of consumption/digestion in our body as well as interference of sugar and milk as the additives.

The purpose of this paper is to investigate the effects of green tea extract on kidney function tests, in male rats that received different doses of acrylamide (AA).

Animals were dispensed at random to one of the following treatments: group 1 served as control, whereas groups 2, 3 received seven, 14 mg/100 g B.W/day of AA, respectively, in drinking water for 15 and 30 days. Group 4 received green tea 1.5 percent concentration and groups 5, 6 received seven, 14 mg/100 g B.W/day in a mixture with green tea for 15 and 30 days.

Serum urea and creatinine significantly increase with AA. However, Total protein, albumin and A/G ratio showed significant drop in all treated groups when compared with control. Supplementation of rats with antioxidant (green tea) enhanced the general health condition, reduced the severity of genotoxic effect and the alteration in blood and serum parameters produced by AA.

The authors suggest that green tea may deliver a cushion for long therapeutic option against toxins-induced nephrotoxicity without damaging side effects.

The study uses green tea as a natural antioxidant source. Epigallocatechin-3 gallate is the most plentiful catechin preserved in green tea and a high source of flavonoids. Flavonoids are a group of phenolic products of plant metabolism with high antioxidant properties to reduce nephrotoxicity without side effects.