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Alzheimer’s disease (AD) is the most common neurodegenerative disease characterized by cognitive decline and memory impairment. Many lines of evidence indicate that excessive β-amyloid peptide (Aβ) generation and aggregation play pivotal roles in the initiation of AD, leading to various biochemical alteration including oxidative damage, mitochondrial dysfunction, neuroinflammation, signaling pathway and finally resulting in neuronal death. AD has a complex pathogenic mechanism, and a single-target approach for anti-AD strategy is thus full of challenges. To overcome these limitations, the present study focused to review on one of multiple target-compounds, (–)-epigallocatechin-3-gallate (EGCG) for the prevention and treatment of AD. EGCG is a main bioactive polyphenol in green tea and has been reported to exert potent neuroprotective properties in a wide array of both cellular and animal models in AD. This review demonstrated multiple neuroprotective efficacies of EGCG by focusing on the involvement of Aβ-evoked damage and its Aβ regulation. Furthermore, to understand its mechanism of action on the brain, the permeability of the blood-brain barrier was also discussed.

Water infusion of pan-fried minimally oxidized leaves of plant Camellia sinensis is recognized as green tea. This infusion is rich in catechins, the bioactive components responsible for its health-promoting potential. Herbal teas or tisanes are the infusion or decoction of plant parts other than Camellia sinensis. Tisanes are generally known for their refreshing taste, fragrance, tranquilizing, and antioxidant effects. These infusions are also loaded with different types of phenolic compounds and exhibit multiple health benefits. The popularity and consumption of green tea is on the rise world over, but herbal teas are underutilized. There is a need to explore more about herbal teas and their biological activities especially in comparison to green tea. This review provides an update on the comparative studies carried out between green tea and herbal teas for antioxidant, antidiabetic, antimicrobial and anticancer properties.

Retinitis pigmentosa (RP) is a group of inherited retinal disorders that lead to photoreceptor loss. RP has been reported to be related to oxidative stress, autophagy, and inflammation. (-)-Epigallocatechin gallate (EGCG), the most abundant catechin-based flavonoid in green tea leaves, has significant antioxidant, anti-carcinogenic, antimicrobial, and neuroprotective properties. EGCG, given its low molecular weight and hydrophilic properties, can cross the blood-retinal barrier and is able to reach different ocular tissues such as the lens, cornea, and retina. EGCG has been shown to provide retinal protection against ischemia; sodium nitroprusside-, N-methyl-D-aspartate-, lipopolysaccharide-, light-, sodium iodate-, or H2O2-induced damage and diabetic retinopathy. This suggests that systemic EGCG administration has the potential to protect against retinal degenerative or neurodegenerative diseases such as RP. The aim of this work was to investigate whether EGCG can protect against RP progression in the animal P23H line 1, the model of RP. Albino P23H rats were crossed with pigmented Long Evans rats to produce offspring exhibiting the clinical features of RP. Pigmented P23H rats were treated via intraperitoneal injection with saline or EGCG at a dose of 25 mg/kg every week from P100 to P160 and then compared to wild-type Long Evans rats. Rats treated with EGCG showed better visual and retinal electrical function with increased contrast sensitivity and b-wave values compared with those observed in P23H rats treated with vehicle. EGCG reduced lipid peroxidation and increased total antioxidant capacity and catalase and superoxide dismutase activities. No differences were observed in visual acuity, nitrate levels, nitrite levels or glutathione S-transferase activity. In conclusion, EGCG not only reduced the loss of visual function in P23H rats but also improved the levels of antioxidant enzymes and reduced oxidative damage. This study was approved by the Institutional Animal Care and Use Committee (CEICA) from the University of Zaragoza under project license PI12/14 on July 11, 2014. This study was supported by the Instituto de Salud Carlos III (project PI13/01124 and Ocular Pathology National Net RETICS-Oftared RD16/ 0008) the Fondo Europeo de Desarrollo Regional (FEDER) funds: “Una manera de hacer Europa”; and the Government of Aragon (Group B08_17R and Predoctoral Grant L. Perdices, C060/2014).

Green tea is one of the main teas in China, which is unfermented and retains more natural substances of fresh tea leaves. This is the preliminary study of application of'fingerprints' based on differences in component composition of green tea. Five green teas from different areas in eastern China are analyzed, which are processed by microwave-assisted solvent (ethanol) extraction method to obtain tea polyphenols, flavonoids, polysaccharides, pigments (thearubigins, theaflavins, theabrownins). The results show that the component composition of five green teas are varied from each other; based on these contents varieties, we have constructed a 'fingerprint' and applied linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA) to assist in the identification of these five green teas. This method does not require large, expensive instruments (such as high performance liquid chromatograph, gas chromatograph, mass spectrometer, etc.), and is easy to use, which provides a new avenue for the identification of tea. Keywords: Green tea, contents varieties, identification, 'fingerprints'.

Brewing water plays a crucial role in flavor and potential healthy functions of tea infusion. In this study, seven water samples with different physicochemical properties were selected to brew green tea. Results showed that the brewing water with higher minerals level and pH value would reduce the yield of catechins in tea infusion, which in turn caused the decrease of antioxidant activity to a large extent. Besides, it was found that EGCG, as a major contributor to the antioxidant activity of green tea infusion, was influenced differently by different metal ions, among which Ca2+/Mg2+ could enhance the antioxidant activity of EGCG solutions with different concentration through synergistic effect, particularly Ca2+, and the effect was more markable at a higher EGCG concentration. These results offered theoretical direction to the selection of tea brewing water for consumers and gave a new sight to the effects of metal ions on the antioxidant capacity of EGCG.

The aim of work is study qualitative composition and quantitative content of flavonoids and phenolic acids in green tea leaves. Material and methods. The object of the study was green tea leaves, which were collected in Anhui Province, China. The analysis of 60 % ethanolic extract from green tea leaves was performed by high-performance liquid chromatography using a Prominence LC-20 Shimadzu chromatographic system (Japan) with an SPD-20AV spectrophotometric detector, an Agilent Technologies Microsorb-MV-150 column (reversed-phase, C18 modified silica gel, length – 250 mm, diameter – 4.6 mm, particles size – 5 μm). Identification of substances in the extract was carried out by comparing the retention time and the spectral characteristics of the test substances with the same characteristics of the reference standards. Results. 13 compounds were identified and determined by high-performance liquid chromatography. Among flavonoid aglycones quantitatively dominated by quercetin (0.35 %), in the case of flavonoid glycosides, it was luteolin-6-C-glycoside (1.30 %) and among phenolic acids, it was gallic acid (5.21 %). Conclusions. The qualitative composition, quantitative content of flavonoids and phenolic acids in the green tea leaves were determined by high-performance liquid chromatography. According to HPLC, the content of flavonoids in green tea leaves was higher than the content of phenolic acids.

Summary Background Green tea (Camellia sinensis) has bioactive compounds that have been shown to possess nutritive effects on various biomolecular processes such as immunomodulation. This research explores the immunomodulatory effects of green tea in reducing transplant rejection. Method The study employs computational systems biology: 1) to identify biomolecular mechanisms of immunomodulation in transplant rejection; 2) to identify the bioactive compounds of green tea and their specific effects on mechanisms of immunomodulation in transplant rejection; and, 3) to predict the quantitative effects of those bioactive compounds on immunomodulation in transplant rejection. Results Three bioactive compounds of green tea – epicatechin (EC), gallic acid (GA), and epigallocatechin gallate (EGCG), were identified for their potential effects on immunomodulation of transplant rejection. Of the three, EGCG was the only one determined to enhance anti-inflammatory activity by: 1) upregulating synthesis of HO-1 that is known to promote Treg and Th2 phenotypes associated with enabling transplant tolerance; and, 2) downregulating pro-inflammatory cytokines IL-2, IL-17, IFN-γ, TNF-α, NO, IL-6, and IL-1β that are known to promote Th1 and Th17 phenotypes associated with transplant rejection. Conclusions To the best of our knowledge, this study provides the first molecular mechanistic understanding the clinical nutritive value of green tea, specifically the bioactive compound EGCG, in enabling transplant tolerance.

Japanese green tea (Sencha) is mainly manufactured by six processing steps: steaming, primary rolling, rolling, secondary rolling, final rolling, and final drying. The morphology and microstructure of tea leaves were observed, and total polyphenol content (TPC) and total antioxidant activity indexed by FRAP and DPPH were evaluated in tea leaves and infusions during processing. Folds or wrinkle-like microstructures on the tea leaf surface increased during processing, particularly during the primary rolling (PR) step. Leaf shape also mainly collapsed during the PR step. In tea leaves, the values of TPC, DPPH, and FRAP during processing ranged from 189 to 283 mg GAE/g dry matter (DM), 2670–4363 μmol FeSO4/g DM, and 1519–2327 μmol TE/g DM, respectively, whereas in the hot water extraction as a tea infusion decreased and ranged from 14 to 135 mg GAE/g, 391–2961 μmol FeSO4/g DM, and 219–1049 μmol TE/g DM, respectively. These functional attributes increased mainly from steaming (ST) to rolling (RL) steps. The results indicated that the processing conditions at each step, especially at the steps for ST, PR, and RL, influenced the apparent quality of the final tea leaf products and the functional properties of tea leaves and infusions.

The purpose of the current study was to investigate the effect of green tea ethanol extract (GTE) and polysaccharide fractions from green tea (PFGs) on the hydrolysis of wheat starch, microstructural changes, and intestinal transport of glucose. The amount of resistant starch (RS) was significantly lowered in the water-soluble polysaccharide (WSP), water-soluble polysaccharide-pectinase (WSP-P), and water-insoluble polysaccharide-alkali soluble (WISP-Alk-Soluble; p < 0.05). The microstructures of gelatinized wheat starch granules with WSP, WSP-P, and WISP-Alk-Soluble were spherical with small cracks. The amount of intestinal transported glucose from digested wheat starch was 2.12-3.50 times lower than the control group. The results from the current study suggest that water- and alkali-soluble PFGs could be potential ingredients to lower starch hydrolysis as well as to control the postprandial blood glucose level when foods that contain starch are consumed.

Medicinal plants and dietary supplements may provide an effective and safe treatment for pain relief. Green tea is one of the most common beverages with many several pharmacological activities. The results of various studies have indicated that green tea possesses antinociceptive effects. Many of the protective effects of green tea in terms of pain relief are attributed to its antioxidant and anti-inflammatory properties. Epigallocatechin -3-gallate (EGCG), as one of the major phytochemical components in green tea, is effective in the management of pain through suppression of inflammation and oxidative stress. We have reviewed the effects of green tea on pain and also discussed mechanisms involved in pain relief. This review suggests that green tea can be a safe and often effective treatment for pain.

Adipose browning leads to increased energy expenditure and reduced adiposity and has, therefore, become an attractive therapeutic strategy for obesity. In this study, we elucidated the effect of green tea aqueous extract (GTAE) on the browning of inguinal white adipose tissue (Ing‐WAT) and brown adipose tissue (BAT) in high‐fat diet (HFD)‐fed mice. The main phytochemical components identified in GTAE through high‐performance liquid chromatography (HPLC) included (−)‐gallocatechin, (−)‐epigallocatechin, (−)‐catechin, (−)‐epigallocatechin‐3‐gallate, caffeine, (−)‐epicatechin, (−)‐gallocatechin gallate, and (−)‐epicatechin‐3‐gallate. Daily supplementation with 1% GTAE for 12 weeks markedly reduced bodyweight gain, systemic inflammation, oxidative stress, and improved insulin resistance. Additionally, histological analysis revealed that dietary supplementation with 1% GTAE reversed HFD‐induced adipocyte size and hepatic steatosis. These effects were associated with activation of browning in the Ing‐WAT and BAT, which mediate systemic metabolic dysfunction in HFD‐fed mice. Taken together, our data support the use of GTAE, a natural product, for the attenuation of obesity through the activation of fat browning., The present study found that mice fed a high‐fat diet showed significantly lower weight gain upon GTAE administration than their control counterparts. In addition, GTAE ameliorated the high‐fat diet‐induced hepatic steatosis, insulin resistance, and low‐systematic inflammatory. These effects were associated with browning activation in the Ing‐WAT and BAT.

Tea leaves (Camellia sinensis) have many health benefits due to their abundance of polyphenols with antioxidant activity, most notably epigallocatechin‐3‐gallate (EGCG). To protect those bioactive compounds, the spray‐drying technique of green tea‐extracted solution is conducted because of encapsulating. This study aimed to optimize the spray‐drying condition using the response surface methodology (RSM) with respect to the maximal polyphenol content of the product. Furthermore, the characterizations of resulting powder were determined. The results showed that optimal spray‐drying temperature, input flow rate, and whey protein isolate (WPI) content were evaluated at 136℃, 6.8 rpm, and 10.3% of dry basis, respectively. The obtained green tea powder products, which got from optimal spray‐drying process, achieved total polyphenol content (TPC), EGCG, and caffeine content of 322.06 mg GAE/g, 11.4%, and 2.8% of dry basis, respectively. This result revealed the feasibility of green tea leaves to produce tea powder rich in EGCG and polyphenols by spray‐drying technique, potentially contributing to the diversification of tea products., The spray‐drying process to make tea powder from the extract was optimized by RSM with response of total polyphenol. The tea powder product shows attractive characterization of remained total polyphenol, chlorophyll, EGCG, and caffeine.

The world’s older population continues to grow at an unprecedented rate. Iran is 1 of the countries where the aging population is higher than the global average. Depression is 1 of the most common issues in older adults that can be managed by nonpharmacologic interventions such as the consumption of green tea. The aim of this study was to determine the effect of green tea consumption on depression in the elderly people. In this quasi-experimental study, 76 elderly people who were residents in a nursing home and met the inclusion criteria were selected through simple random sampling. Then, green tea in 3-g tea bags was brewed in 80°C water and half an hour after breakfast and lunch was given to the participants in a 5-week protocol. One day after the last time of brewing green tea, participants were assessed with a standard depression questionnaire. The obtained data were analyzed using SPSS Version 19 software (IBM Corp, Armonk, NY). The descriptive statistics and Wilcoxon statistical test analysis were also conducted at a significant level of P

Tea is one of the most widely consumed aromatic beverages in the world because of its taste and flavor, as well as due to many potential health beneficial properties. Metabolomics focuses on an in-depth analysis of all metabolites in living organisms. In this study, 29 primary metabolites and 25 secondary metabolites were identified using GC/MS and UPLC-QTOF/MS, respectively. Further, PCA analysis showed conspicuous discrimination for the ten varieties of green tea with metabolite profiling. Among them, organic acids, amino acids, flavan-3-ols, and flavonol glycosides varied greatly through checking the VIP values of the PLS-DA model. Moreover, the intrinsic and/or extrinsic factors characterizing each type of green tea were also discussed. The chemical component marker derived here should be used as an important detection index, while evaluating the tea quality, as well as while establishing the tea quality standard.

Hair growth tonics containing herbal and synthetic ingredients have been developed to overcome hair loss and baldness. Advanced technological developments made many Indonesians prefer to use herbal products compared to synthetic products due to their fewer side effects. Green tea leaves (Camellia sinensis L.) is a plant believed to increase hair growth rates due to its flavonoid compounds. The purpose of this study is to formulate hair tonic from water fraction ethanolic extract green tea leaves, to look at the activity of hair growth-promoting, and also to look at physical stability, irritation tests, and microbial contamination. The positive control used is 2% Minoxidil. The hair growth activity test was carried out by applying a hair tonic to rabbits. Hair growth measurement data were statistically tested by the ANOVA test. The formulated green tea leaves tonic met the physical properties test. The tonic produces similar growth activities with the positive control (significance difference (p> 0.05)). In addition, the tonic does not have a skin irritation effect on rabbit skin and is free from bacteria.

Benifuuki is a cultivar of tea (Camellia sinensis) that contains 3"-O-methylated epigallocatechin gallate (EGCg3"Me). In vitro, animal and human studies have shown positive health effects of Benifuuki tea (or more specifically of EGCg3"Me), such as allergy mitigation or prevention of cardiovascular diseases. In this article, suitability of the ISO 14502-2 method (slightly modified), that has been set up for the analysis of other flavanols in tea, was shown to be suitable for EGCg3"Me and validated. Eight Benifuuki green tea samples from Japan were analyzed and contained 2.3 to 10.5 mg EGCg3"Me per g in the leaves. Additionally, tea infusions were brewed according to the suppliers' recommendations and at 100 °C. The content of EGCg3"Me in the infusions was compared to the effective doses in human trials. Three Benifuuki infusions brewed at recommended temperatures of 60 or 85 °C deliver in less than 2.5 L at least 34 mg of EGCg3"Me, which is the minimal dose showing health effects in human studies. Using water of 100 °C, the EGCg3"Me concentration in the infusions is roughly doubled. Some infusions exceeded the safe level of caffeine of 400 mg within drinkable volumes.

Many human studies suggest a benefit of tea consumption on bone health. The study objective was to compare the ability of different tea types to promote mineralization. Saos-2 cells underwent mineralization (5 days) in the presence of tea (white: WT, green: GT, black: BT, green rooibos: GR, or red rooibos: RR; 1 μg/mL of polyphenols) or control. Total polyphenol content (TPC, Folin-Ciocalteu's reagent), antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl [DPPH] scavenging), mineralization (Alizarin Red staining), gene expression quantitative reverse transcription PCR (RT-qPCR), and cell activity (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay) were determined. TPC was highest in GT and BT. The ability of each tea to inhibit DPPH also differed (WT, GT > RR) after normalizing for polyphenol quantity. Each tea increased mineralization and differences were observed among types (GT/BT/GR/RR > WT, GT = BT = GR, RR > BT/GT). mRNA expression of alkaline phosphatase (ALP) and ectonucleotide pyrophosphatase/phosphodiesterase (NPP1) remained unchanged, whereas osteopontin (OPN) and sclerostin (SOST) were reduced in cells treated with tea, regardless of type. At 24- and 48-h postexposure to tea, cell activity was greater in cells receiving any of the teas compared with vehicle control. Supplementation increased mineralization regardless of tea type with both rooibos teas and black tea stimulating greater mineralization than WT, whereas green tea is similar to the others. While future study is needed to confirm in vivo effects, the results suggest that consuming any of the teas studied may benefit bone health.

Tea and mainly green tea as a rich source of antioxidants has been widely known for some time. The antioxidant capacity of tea including green tea is mainly due to its catechins content. The objective of this study was to determine the relationship between the ORAC value and the catechins content. Regular and decaffeinated commercial green tea bags commonly consumed in the United Kingdom (UK) have been examined using Reversed-Phase High-pressure Liquid Chromatography (RP-HPLC). Teabags were purchased from different local supermarkets in the UK and extracted with natural mineral water at temperature 100°C for 9 minutes at the pre-adjusted pH 4. The level of four catechins (Epi-structured) for the thirteen types of green tea were separated and determined by HPLC analysis, i.e. ()-epigallocatechin (EGC), ()-epicatechin (EC), ()-epigallocatechin-3-gallate (EGCG) and ()-epicatechin gallate (ECG). The standard graphs were validated using certified reference catechins supplied by the Laboratory of the Government Chemist (LGC). The levels of total catechins and oxygen radical absorbance capacity (ORAC) values varied from 34.61to 204.55 mg/g, 830.19- 4197.81 Trolox equivalents/g tea bags for thirteen types of green teas respectively. It was clear from the results of this study that there was a significant linear and positive correlation (r = 0.951, df = 12, p < 0.05) is found to exist between the total catechins contents and ORAC values. It can be concluded that the results of catechins measurements coupled to this; the well-known ORAC assay was successfully modified to measure the antioxidant capacity of the green tea extracts throughout this study. Furthermore, the higher the level of catechins the higher is the antioxidant capacity of the tea. This may stimulus consumers in selecting the type of tea and tea brewing times, exhibiting more health benefits. Nevertheless, the differences between the studied brands are owing to shelf life, production and storage conditions.

Green tea obtained from the leaves of Camellia sinensis (L.) Kuntze having potential health benefits. It contains significant amounts of antioxidant and is considered as world healthiest drink. Polyphenols in tea are thought to exhibits anti-carcinogenic and anti-inflammatory effects. Green tea catechins acts as immune modulators in immune dysfunction and also play a role in protection from degenerative diseases. Intake of green tea catechins suppress high fat diet induced obesity, prevent lipid and glucose metabolism disorders and reduce risk of coronary heart disease. Green tea constituent epigallocatechin-3-gallate (EGCG) is a potential antioxidant that shows protective effects against photo toxicity and photo carcinogenesis. In vitro animal experiments have suggested that polyphenols in green tea protect from lung cancer by their antioxidant and antimutagenic properties. This study chiefly highlights the convenience of green tea on health and propagates its further prospects.

Introduction: Green tea is related to the reduction of liver enzymes, lipoprotein, and body mass index. However, some reports related green tea to the risk of developing liver cancer, but their outcomes were conflicting. Hence, the present study aimed to determine the relationship between green tea intake and lipoprotein, liver enzymes, body mass index, and liver cancer. Methods: A systematic literature search up to January 2020 was performed and 22 studies included 169599 subjects with 97316 of them use green tea intake. Odds ratio (OR) or mean difference (MD) with 95% confidence intervals (CIs) was calculated to evaluate the relationship between green tea intake and lipoprotein, liver enzymes, body mass index, and liver cancer using the dichotomous or the contentious method with a fixed effect or a random effect models. Results: Green tea intake significantly lowered the risk of developing liver cancer, and body mass index compared to no green tea intake. Also, there was a significant lowering effect of green tea intake on liver enzymes, lipoprotein compared to no green tea intake. However, no significant different was found between green tea intake and no green tea intake on high-density lipoprotein. Conclusions: Based on this meta-analysis, green tea intake had a significant lowering effect on the risk of developing liver cancer and had a significantly improving effect on body mass index, liver enzymes, and lipoprotein compared to no green tea intake. These results suggest that green tea may be added to the daily dietary program to improve cardiovascular status with no possible risk of liver cancer. It even may have a protecting effect against liver cancer in the usual daily number of cups.

The chemical composition and sensory evaluation of yoghurt supplemented with green tea (GTE) or green coffee (GCE) extracts and its effect on reducing obesity complications in rats were investigated. Ethanol extracts were prepared from green tea and green coffee and their total phenolic compounds and identified phenolic compounds were evaluated. Results showed that the GTE and GCE have containing highly antioxidant activities. Yoghurt was prepared from low fat buffalo's milk (1.5% fat) blended with 1 % of GTE or GCE. Addition of GTE or GCE had significant effects on the chemical composition and sensory evaluation. Higher sensory scores were reported flavor for GTE and GCE yoghurt than control. It was also noticed that addition of GTE or GCE to yoghurt increased viscosity a key defensive effect on the gel-factors. Feeding of obese rats on yoghurt adding to GTE or GCE showed that significant differences reduced of weight compared to positive group. There are not found significant differences of heart weights tissue while, kidney and liver weights tissues were significant differences. Also, fed obese rats on yoghurt supplemented with GTE or GCE decreased the lipids profile comparative with positive control group and improvement of liver and kidney functions. The best treatment was observed in yoghurt adding to green coffee beans extract which had reduced value of liver and kidney function parameters followed by yoghurt adding to green tea extract. The histopathological examination observed normalized in the groups fed yoghurt supplemented green tea and coffee beans extracts. Supplemented yoghurt with green tea and coffee extracts could be increased the useful health effects of yogurt by intensifying antioxidant activity which had therapeutic effects on obese rats.

Tea is a rich source of functional components called polyphenols which impart it antioxidant properties. Tea is categorized as green or black tea according to the processing method used. Tea is widely consumed beverage, and it is often prepared with the addition of milk and sugar in many parts of the world including India. The present study was conducted to compare the effect of addition of milk and/or sugar, in both black and green teas of two brands (1 and 2), on the antioxidant properties of teas. The total polyphenol, flavonoid and catechin contents along with antioxidant activity were significantly (p

Acne is one of the most common skin diseases and usually affects almost everyone. Herbal remedies can be given to treat acne and do not cause side effects. The purpose of writing is to see the effectiveness of herbal remedies for healing acne. Methods: Recent literature reviews were conducted using the electronic databases of Pubmed, Wiley Online and Science Direct. The review method uses keyword terms and phrases of Herbal Medicine, Acne, and Facial Treatment. Results: From the results of 9 studies, it was found that there was anti-acne activity of herbal plants and was relatively safe because there were no severe side effects compared to conventional or synthetic treatments. And there is the effectiveness of herbal remedies for healing acne. Conclusion: Herbal plants have antioxidant, anti-inflammatory, antibacterial and anti-inflammatory effects. Some of the recommended plants based on journal reviews for treating acne include: Nigela Sativa L, Amurense Phellodendron, Tea Tree Oil, Mangosteen Fruit Skin, Aloe Vera, Lavandulla, Paper Murbey, Green Tea, Hops, Aloe Ferox, Punica Granatum (Pomegranate).

The relationships between the total available antioxidant capacity of green tea and the brewing temperature and preparation time were studied, with the Trolox equivalent antioxidant capacity (TEAC) assay used to determine the antioxidant levels. The initial green tea mass-to-water volume ratio was set to 10 g/L, %-inhibition values were determined at various concentrations through serial dilution, and the slope of the relationship between %-inhibition and concentration was used to determine the TEAC value. The total antioxidant capacities of green tea determined under the experimental conditions adopted in this study are in the 214-819 μmolTrolox/ggreen tea range, which is significantly higher than previously reported values for various common fruits and vegetables. The total available antioxidant capacity was found to increase with temperature at a rate of approximately 6 (μmolTrolox/ggreen tea)/°C when brewed for 4 min. Green tea concentration, brewing time, and brewing temperature were experimentally determined to be the primary factors that determine the antioxidant capacity.

How the anthropogenic addition of nutrients, especially nitrogen (N), impacts litter decomposition has attracted extensive attention, but how environmental factors other than nutrients affect the impacts of N addition on litter decomposition is less understood. Since different local litters could respond differently to N addition, standard materials are necessary for comparing the impacts among various environments. The present study tested if tea bags used for the Tea Bag Index (TBI) approach, i.e., constructing an asymptote model by using a green tea decomposition datum and a rooibos tea decomposition datum (single measurement in time), can be standard materials for testing the impacts of N addition on litter decomposition in aquatic ecosystems. A laboratory incubation experiment was performed using a water sample taken from a stream in Kumamoto, Japan. Since a recent study suggested that the TBI approach may be inapplicable to aquatic ecosystems, a time-series data approach, i.e., fitting models to time-series mass loss data of tea bags, was also used for testing if tea bag decomposition can pick up the impacts of N addition on aquatic litter decomposition. The time-series data approach demonstrated that N addition significantly suppressed rooibos tea decomposition, whereas green tea decomposition was not affected by N addition. The TBI approach was unsuitable for testing the sensitivity of the response of tea bag decomposition to N addition because the TBI-based asymptote model failed to predict the observed data, confirming the suggestion by a previous study. Overall, the present study suggested that the tea bags can be used as standard materials for testing the impacts of N addition on litter decomposition in aquatic ecosystems, but only when using a time-series measurement and not the TBI.

In this research, kombucha tea was prepared using 5 different tea extracts and physicochemical and sensory analyses were made. The tea extracts used are black tea, green tea, sage, linden and mint, respectively. The prepared tea samples were subjected to fermentation for 14 days. In tea samples, pH, electrical conductivity, water-soluble solid and phenolic components were analyzed before and after fermentation. pH values decreased by an average of 63% in all tea samples after fermentation. The electrical conductivity increased in black tea, green tea and mint tea, while sage and linden decreased. Brix values decreased in all tea samples, the most decrease was in black tea. Total amount of phenolic contents of kombucha tea samples decreased excluding mint tea sample. As a result of sensory analysis of tea samples, mint tea got the highest score. As a result of the research, it has been determined that the kombucha tea, which is usually made with black and green tea, can be prepared with teas of different flavors and its consumption can be increased. © 2021, Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA. All rights reserved.

People in Bangladesh are traditionally used to consume mainly black tea. However, some tea manufacturing companies are now producing green tea, though in a small scale. To create new knowledge as well as awareness about the consumption of green tea, the present study was carried out to compare the black and green tea available in Bangladesh based on their bioactive compounds and antioxidant activity. A total of eight brands of black tea and two brands of green tea were bought from the supermarkets. Total phenolics, total tannin, total flavonoids, and caffeine content were measured as bioactive compounds, and antioxidant activity was evaluated by using two different methods such as DPPH (1,1- diphenyl-2-picrylhydrazyl) radical-scavenging activity and ABTS+ radical scavenging activity of methanol extracts of black and green tea. Every bioactive compound in black and green tea was found to be significantly different (P < 0.05). The total phenolic content, on average, was measured at 242.46 mg GAE/g dry extract and 763.41 mg GAE/ g dry extract in black and green tea, respectively. Black tea contained 6.47 mg TAE/g dry extract tannin, whereas green tea had much more tannin content, 14.51 mg TAE/g dry extract, which is more than double in amount. On the other hand, the total flavonoid content was almost double in black tea (61.82 mg QE/g dry extract) compared to green tea (31.85 mg QE/g dry extract). Antioxidant activities were determined at different concentrations of tea samples. At every concentration, green tea presented higher ABTS+ and DPPH radical scavenging activity than black tea. The highest percentage of inhibition was observed at 20 ppm both in black and green tea, finding 98.50 % and 99.07 % inhibition, respectively. Overall, significantly (P < 0.05) higher amount of phenolic compounds as well as antioxidant activity were observed in green tea.

The effect of using black and green tea waste extracts on the diet nutritional value was investigated with three methods of in vitro degradability, gas production, and McNiven’s enzymatic digestion in the present experiment. Total phenolic compounds and total tannin for green tea extract were 20.3% and 14.8% of dry matter (DM), respectively, and for black tea were 18.7% and 12.7% of dry matter, respectively. The addition of green and black tea waste extracts reduced both gas production during incubation hours and dry matter degradability (DMD) in the diet (p < 0.05). A significantly reduced ruminal dry matter disappearance (p < 0.05) and a significantly increased post-ruminal dry matter disappearance (p < 0.05) were observed by adding black and green tea waste extracts. According to the results, the dry matter disappearance throughout the gastrointestinal tract was not significantly different between treatments. It can generally be concluded that the addition of phenolic compounds can be used depending on the nutritional strategy, such as reducing ruminal degradability and increasing rumen nutrient escape.

Heavy application of nitrogen (N) in tea (Camellia sinensis (L.)) plantations causes various environmental problems. To date, studies on N flows have been limited to the tea plantation level, but the crucial drivers of N flows are consumers, not farmers. Therefore, this study aimed to evaluate changes in N flows concerning green tea production and consumption in Japan from 1965 to 2016 using the N footprint concept. Nitrogen use efficiency (NUE), virtual N factor (VNF), and N footprint were calculated using a Monte Carlo method from data for 17 parameters obtained from the literature review. The VNF for green tea in Japan decreased from 54.5 in 1991 to 30.8 in 2016. The major reasons for this decrease were (i) increased NUE in plantations and (ii) increased consumption of ready-to-drink (RTD) tea, matcha, and powdered tea, indicating an increase in the efficiency of N intake from green tea by consumers. The decrease in VNF resulted in a reduction in N footprint from green tea consumption. However, the decline in N footprint since 2004 is not derived from the decrease in VNF but mainly from reduced green tea consumption. A sensitivity analysis revealed that the parameters associated with the extraction efficiency of tea, powdered tea production, and the amount of tea leaves used for RTD production strongly affected VNF estimation.

Shehla Wasim Haque,1 Vidya-Saraswathi Muliya,1 Krishnaraj Somayaji,1 Kalyana-Chakravarthy Pentapati2 1Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India; 2Department of Public Health Dentistry, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, IndiaCorrespondence: Vidya-Saraswathi MuliyaDepartment of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, IndiaTel +91 944-825-2360Email vidya.saraswathi@manipal.eduObjective: To compare the color stability of the newer glass ionomer cements (GIC) when exposed to “Green tea” (GT), “Tulsi tea” (TT), and “Areca tea” (AT) using spectrophotometric analysis.Materials and Methods: We selected commercially available GC Fuji IX GP EXTRA and Ketac Universal for this study. Eighty disc-shaped samples were made using a mold, which were immersed in the freshly prepared test solutions (distilled water, GT, TT, and AT) for 15 minutes per day for 60 days. The color estimation was done using a spectrophotometer.Results: GC Fuji IX samples had a significantly higher mean difference in ΔE value than Ketac Universal when immersed in GT, AT, and control (P< 0.001, 0.018, and < 0.001), respectively. With GC Fuji IX, GT and AT stained more than TT and control solutions. Samples of Ketac Universal showed a significantly higher mean difference in ΔE values when immersed in AT, followed by GT, TT, and control.Conclusion: Within the study’s limitations, we conclude that both the GICs exhibited staining over time on exposure to all the test solutions. Ketac Universal demonstrated lower staining potential than GIC Fuji IX GP Extra for GT and AT.Keywords: staining, glass ionomer cement, dental, tea

The tea bag method provides a replicable and standardized method to study the effect of environmental variables on the decomposition of standard litter, which enables comparison of organic matter decomposition rates on a large scale. However, it remains uncertain whether tea bag decomposition in response to wetness is representative of that of local litters. We performed incubation experiments to examine whether the effect of soil water on tea bag decomposition becomes inhibitory at higher water contents, as is the case in local leaf litters. In addition, we performed field studies in a mixed forest and cedar plantation in Japan to compare two litter bag mesh sizes: 0.25-mm mesh, the size previously used by a major manufacturer of tea bags (Lipton), and nonwoven bags with mesh sizes finer than 0.25 mm, which are currently produced by Lipton. Both green tea and rooibos tea exhibited higher decomposition rates at higher water contents, but decomposition was inhibited at the highest water content, this was in contrast to our hypothesis based on a field observation but consistent with conceptual models of local litters. The nonwoven tea bags did not show lower decomposition rates, despite the finer mesh size. Rather, the nonwoven rooibos tea bags exhibited slightly higher decomposition rates than the 0.25-mm mesh bags in the cedar plantation, possibly due to a greater abundance of microorganisms that decompose litters in the nonwoven bags, due to the decrease in predation by mesofauna. Our findings provide essential information for future studies of tea bag decomposition.

Green tea and its medical advantages assume a job in oral cavity. High atomic weight polyphenols are separated from green tea have cell reinforcement, antibacterial cariostatic, antitumor exercises. It also helps to treat dental caries, periodontal diseases, and also for treating cancers. Keywords: Green tea, Antioxidants, Dental caries, Carotenoids, Epigallocatechin.

Inflammatory bowel disease (IBD) is a chronic gastro-intestinal disorders of unknown etiology. There are several drugs approved for treating IBD patients with active disease, including first-line use of aminosalicylates, and secondary choices of immunomodulators and other therapies. These medications might manage disease symptoms, but have also shown significant side-effects in IBD patients. Tea is the second largest beverage in the world and its main active ingredients including tea polyphenols, polysaccharides and tea pigments have been shown promising anti-inflammatory and antioxidant properties. In this review, we summarize the influence of different tea varieties including green tea, black tea and dark tea as potential nutritional therapy for preventing and treating IBD, and discuss the mechanisms of tea ingredients involved in the regulation of oxidative stress, inflammation, signaling pathways, and gut microbiota that could benefit for IBD disease management. Our observation directs further basic and clinical investigations on tea polyphenols and their derivatives as novel IBD therapeutic agents.

The high antioxidant capacity of tea is well-known, but the effect of flavorings like honey or lemon has been less studied. Their antioxidants can interact with each other, the global result being also affected by the brewing temperature.The combined effect of heat (55 and 80 °C) and flavorings (acacia and honeydew honeys, lemon juice) on the total polyphenol, total flavonoid content and antioxidant capacity of black and green teas was studied.In many cases higher antioxidant capacity was obtained at 80 °C. Teas flavored with honeydew honey had higher antioxidant capacity than those containing acacia honey. Addition of lemon decreased the antioxidant capacity of tea with honey. No synergies were confirmed in any of the compositions investigated. Vitamin C content of lemon-containing black tea was reduced by half at 80 °C compared to tea brewed at 55 °C; while honey was shown to partly prevent this loss of ascorbic acid.

Periodontal diseases are highly prevalent and can affect high percentage of the worlds’ population. Oxidative stress and inflammation play an important role in the pathogenesis of periodontal diseases. Nowadays, more attention has been focused on the herbal remedies in the field of drug discovery. Green tea is an important source of polyphenol antioxidants. It has long been used as a beverage worldwide. The most interesting polyphenol components of green tea leaves that are related with health benefits are the catechins. Taken together, this review suggested that green tea, with its wide spectrum of activities, could be a healthy alternative for controlling the damaging reactions seen in periodontal diseases.

The study was conducted to evaluate the effect of black cumin extract (BCD), green tea extract (GTD), black cumin oil (BCO), and green tea oil (GTO) (10%) on the proximate, microbial, physicochemic...

BACKGROUND Pymetrozine is a widely used pesticide. It is challenging to analyze and difficult to manage due to the large gap in its global maximum residue limits (MRLs) in tea. The development of a high-efficiency detection method for the evaluation of the transfer of residual pymetrozine from tea plantations to tea cups is therefore of prime significance. RESULTS An analytical method for the determination of pymetrozine residues in tea was established based on Cleanert PCX solid-phase extraction. The average recoveries were 72.2-93.7%, with relative standard deviations (RSDs) of less than 12%. The limits of quantification (LOQs) were 0.005 mg·kg-1 in fresh tea leaves and dry tea, and 0.00025 mg·L-1 in tea brew. Pymetrozine degraded rapidly in tea plants with a half-life (t1/2 ) of 1.9 days in open tea plantations, and decreased by 9.4-23.7% in the green tea-processing procedure, which was concentration dependent. The residual pymetrozine levels in green tea collected at 6 and 21 days were below the MRLs in China and EU at a dosage of 30 g a.i. ha-1 , respectively. The leaching rates of pymetrozine from dry tea to tea brew were 58.7-96.3%. Hazard quotient (HQ) values of pymetrozine were significantly

Study of the qualitative composition and quantitative content of some groups of BAS in dietary supplements with green tea leaf extract Recently, there has been a high demand from the population for dietary supplements that have antioxidant activity. First of all, these are dietary supplements with green tea leaf extract, because green tea contains catechins in a fairly high amount. Nowadays, according to the current legislation of Ukraine the qualitative composition and quantitative content of biologically active substances in dietary supplements are not established, which to a certain extent affects the quality and safety of these products. The aim of the study was to determine the qualitative composition and quantitative content of some groups of BAS in dietary supplements with green tea leaf extract. Materials and methods. Three dietary supplements from different manufacturers “Green Tea Extract”, “Green Tea Extract”, “Green Tea” were chosen for the study. Qualitative analysis was performed by thin layer chromatography, for quantification spectrophotometry in the UV-region was used. Results. The presence of catechins was found in the studied dietary supplements, caffeine was found only in trace amounts. The total content of catechins is 146.80 ± 1.36 mg, 79.00 ± 0.88 mg, 28.00 ± 0.75 mg, and in terms of green tea extract, which is stated in dietary supplements for dietary supplements “Green Tea Extract”, “Green Tea Extract”, “Green Tea”, respectively. Conclusions. Qualitative and quantitative analysis of some groups of BAS of three dietary supplements with green tea leaf extract was performed. It was found that dietary supplements “Green Tea Extract” and “Green Tea” meet the requirements of the US Pharmacopoeia 38 in terms of catechins. Based on the study, it can be concluded that the problem of compliance with dietary supplements is relevant today and requires the introduction of regulatory documentation for the detection and determination of biologically active substances in dietary supplements.

COVID-19 pandemic results in record high deaths in many countries. Although a vaccine for SARS-CoV-2 is now available, effective antiviral drugs to treat coronavirus diseases are not available yet. Recently, EGCG, a green tea polyphenol, was reported to inhibit SARS-CoV-2 3CL-protease, however the effect of EGCG on coronavirus replication is unknown. In this report, human coronavirus HCoV-OC43 (beta coronavirus) and HCoV-229E (alpha coronavirus) were used to examine the effect of EGCG on coronavirus. EGCG treatment decreases 3CL-protease activity of HCoV-OC43 and HCoV-229E. Moreover, EGCG treatment decreased HCoV-OC43-induced cytotoxicity. Finally, we found that EGCG treatment decreased the levels of coronavirus RNA and protein in infected cell media. These results indicate that EGCG inhibits coronavirus replication., Graphical abstract Image 1

Background Chlorpyrifos (CPF) is a broad-spectrum organophosphorus pesticide widely used to control tea geometrid (Ectropis oblique) and tea green leafhoppers (Empoasca pirisuga Matsumura) in tea trees. The major metabolite of CPF in water, plants, and animals is 3,5,6-trichloro-2-pyridinol, which is more toxic than CPF. However, the dissipation pattern of CPF in tea is unknown. Results An optimized QuEChERS sample preparation method combined with ultra-performance liquid chromatography-tandem mass spectrometry was applied to determine the residues of chlorpyrifos and its metabolite in tea during tea planting and green tea processing. During tea planting, the sum of chlorpyrifos and its metabolite dissipated rapidly with a half-life of 1.93 days for tea shoots. The residues of chlorpyrifos and its metabolite in made green tea were 96.89 and 35.88 μg kg-1 on the seventh day. The values for processing factors of chlorpyrifos and its metabolite were all less than 1, showing that each green tea manufacturing step was responsible for the reduction. The transfer rates of chlorpyrifos and its metabolite from made green tea to its infusion were 0.68-4.62% and 62.93-71.79%, respectively. Conclusion The risk of chlorpyrifos was negligible to human health based on the hazard quotient, which was 7.4%. This study provides information relevant to the reasonable application of chlorpyrifos in tea planting and is potentially helpful for tea exporting and importing countries to establish harmonized maximum residue limits. © 2020 Society of Chemical Industry.

Green tea is a popular drink containing a rich profile of polyphenolic compounds responsible for its various health benefits. The clinical reports suggested limited efficacy of green tea in prevent...

This experiment explored the dietary effects of green tea (Camellia sinensis) in feed supplementation on the development of broiler chicks. Totally, two hundred and seventy‐day‐old male broiler chicks were assigned to 27 broiler groups each with 10 individuals (initial mean body weight 44.2 ± 1.3 g) in a 4 × 2 factorial arrangement. Each chicken group was supplemented with the feed additives of green tea powder. The trial data were measured and obtained based on the records of carcass traits and intestine characteristics of broiler chicken fed with four different additive levels of green tea (0.25%, 0.50%, 0.75%, and 1.00%). The experiment lasted for two trial periods of 21 days and 42 days for each treatment of the green tea supplement with full records of broiler traits. There were interesting results recorded in the majority of broiler intestinal traits between the two trial periods. There are a few significant differences (p, This experiment explored the dietary effects of green tea (Camellia sinensis) in feed supplementation on the development of broiler chicks. Significant statistics of broiler chicken intestine traits of colon diameter and jejunum width were affected by different additive levels of green tea at the 42nd day of age. The trial results suggest that there are some significant improvements in two traits, i.e. colon diameter (overall p = .022) and jejunum width (overall p = .01) among broiler chicks fed with green tea.

The chemical composition of Yuhua tea is in a state of constant change during tea processing. However, the dynamic changes in this complex metabolic process remain unclear. Therefore, we detected the changes of compounds in the five stages of processing of Yuhua tea, and carried out metabolomic analysis based on UPLC–MS. In total, 898 metabolites were detected in the five different stages. In the spreading and fixation processes, the differences in metabolites were the most significant, with 127 and 150 metabolites, respectively, undergoing significant changes. During the spreading period, the levels of amino acids and their derivatives, as well as flavonoids, increased sharply, and most continued to increase or stabilized after spreading. In addition, only 26 and 95 metabolites changed significantly during the rolling and drying processes, respectively. Orthogonal projections to latent structures-discriminant analysis showed that the metabolomics of tea changed significantly during the manufacturing process, especially amino acids and derivatives, flavonoids and lipids. This study provides a comprehensive overview of the metabolic changes during the processing of stir-fried green tea, which has potential significance for quality control and flavor improvement of tea.

BACKGROUND/AIMS: Tea, produced from the evergreen Camellia sinensis, has reported therapeutic properties against multiple pathologies, including hypertension. Although some studies validate the health benefits of tea, few have investigated the molecular mechanisms of action. The KCNQ5 voltage-gated potassium channel contributes to vascular smooth muscle tone and neuronal M-current regulation.METHODS: We applied electrophysiology, myography, mass spectrometry and in silico docking to determine effects and their underlying molecular mechanisms of tea and its components on KCNQ channels and arterial tone.RESULTS: A 1% green tea extract (GTE) hyperpolarized cells by augmenting KCNQ5 activity >20-fold at resting potential; similar effects of black tea were inhibited by milk. In contrast, GTE had lesser effects on KCNQ2/Q3 and inhibited KCNQ1/E1. Tea polyphenols epicatechin gallate (ECG) and epigallocatechin-3-gallate (EGCG), but not epicatechin or epigallocatechin, isoform-selectively hyperpolarized KCNQ5 activation voltage dependence. In silico docking and mutagenesis revealed that activation by ECG requires KCNQ5-R212, at the voltage sensor foot. Strikingly, ECG and EGCG but not epicatechin KCNQ-dependently relaxed rat mesenteric arteries.CONCLUSION: KCNQ5 activation contributes to vasodilation by tea; ECG and EGCG are candidates for future anti-hypertensive drug development.

In recent years, the green process method is attaining mild impact ailments and are nontoxic antecedents and are emphasized in the advancement of nanotechnology. This process subsists environmental sustainability. This study intended for eco-friendly synthesis of iron nanoparticles by using green tea and black tea leaves extract. Polyphenols are the components present in the plants used for the synthesis of metal nanoparticles and are replaced by chemical components. This component is nonlethal and biodegradable. Plants evoke more reliable nanoparticles related to other norms. Green synthesis methods do not require high temperature and energy. The characterization of the Fe- Nanoparticles function is done by using SEM and XRD techniques.

Background: The main bacterial aetiological agents in caries formation are the α -haemolytic Streptococcal species Streptococcus mutans, which has been found to be the initiator of most dental caries. The leaves of Camellia sinensis known as green tea, has properties, such as antibacterial and anti-cariogenic. Epigallocatechin-3-gallate (EGCG) one of the most abundant catechins found in green tea is known to contribute to these effects. Aim: To evaluate the antibacterial effect of green tea catechins namely EGCG on S. mutans with two different methods at different concentrations. Objectives: 1) To assess the antimicrobial efficacy of EGCG by disc diffusion test at concentrations of 100, 75, and 50 μ g/mL. 2) To assess the antimicrobial efficacy of EGCG by Minimum inhibitory concentration (MIC) test at concentrations ranging from 0.2 to 100 μ g/mL. Methodology: Commercially available purest form of green tea polyphenol EGCG was used in the study. Disc diffusion test on agar medium and MIC test was used to determine the susceptibility of the S. mutans to green tea catechins EGCG. Results: The results of the agar well diffusion method showed that the EGCG extract has shown zones of inhibition against S. mutans at concentrations of 100 μ g/mL (28.67 mm), 75 μ g/mL (15.33 mm), 50 μ g/mL (10.33 mm) while that of MIC test of EGCG extract of concentrations ranging from 0.2 to 100 μ g/mL against S. mutans shows that the mean MIC value was 1.07. Conclusion: Catechins in the tea are potentially anti-cariogenic agents which can reduce bacterial presence in the oral cavity and have the potential to be further used for the preparation of dentifrice and mouthwash.

This research was conducted to evaluate the influence of adding increasing levels (0, 250, 500,750, and 1000 μg/mL buffered rumen fluid) of green tea ethanol extract (GTEE) to a basal substrate (50% roughage: 50% concentrate formulated with 50% barley and 50% corn grain) on rumen fermentation, methane emissions, and population of microorganism under in vitro experiment. The potential of gas production (A), methane emission, and methane ratio (mL/mL total gas 24 h) were linearly decreased by increasing the dose of GTEE (p

The aim of current research was to determine the effect of different extraction techniques on the antioxidant capacity of green tea, black tea and ginger polyphenols. Initially, the raw materials were subjected to compositional analysis. Afterward, the bioactive moieties from all the samples were extracted through ultrasound and conventional solvent extraction method using different solvents (i.e. ethanol, methanol and water). Furthermore, the functional ingredients, namely, catechins and theaflavins were isolated by solvent partition method from green and black tea, respectively. In addition, the extracts and isolates were analyzed for their total phenolic and antioxidant profile using various spectrophotometric assays. For the quantification of theaflavins and catechins, a reverse phase HPLC system was used. Results showed that ultrasound (P > .005) proved more effectual for the extraction and isolation of polyphenols (757.33 mg/100 g GAE) from the tested materials among the other extraction techniques (741.66 mg/100 g GAE). Likewise, green tea showed better performance than the rest and in solvents ethanol performed better as compared to their counter parts. Similarly, the isolates showed higher antioxidant potential as compared to their extracts and order of effectiveness was catechins > theaflavins > Ginger freeze dried extract (GFDE).

Methomyl (ME) is a carbamate insecticide that is causes a change in biochemical parameters and affects the oxidative state in the body through the production of free radicals. Herbal medicines deri...

The aim of this study was to determine the levels of myricetin, quercetin, and kaempferol in green and black Kenyan types in relation to geographic location of production. Tea samples were extracted before chromatographic separations with a Shimadzu 20A HPLC coupled with PDA. Flavonol levels were quercetin > kaempferol > myricetin. Teas from east of rift, had quercetin 1.25-1.83 mg/g and 1.29-1.71 mg/g for green and black types, respectively. Kaempferol levels were between 1.28-1.72 mg/g in green and 1.36-1.76 mg/g in black tea. Myricetin ranged at 0.40-0.79 mg/g green and 0.12-0.38 mg/g black tea types. Total flavonols in green tea were highest at 4.28 mg/g while black tea was 3.83 mg/g. These trends agree well with those observed in teas west of the rift. For tea types, myricetin and kaempferol showed a significant difference (P ≤ 0.05) between green and black teas. Total flavonols showed no significant difference. Kenyan teas are a potential dietary source of flavonols myricetin, quercetin, and kaempferol as evidenced by the significant quantities recorded in this study.