Effect Of Black Tea Research Articles

Effects of black tea and black brick tea with fungal growth on lowering uric acid levels in hyperuricemic mice.

Black tea, a traditional drink, can induce urination and quench thirst. Black brick tea with fungal growth, prepared by steaming, pressing, inducing fungal growth, and drying the black tea, is a new type of black tea with different sensory qualities and is suitable for storage. However, the effects of black brick tea with fungal growth on lowering uric acid are still unexplored. Therefore, the potassium oxonate was administered for 7 consecutive days to establish the hyperuricemic mice. Then allopurinol, black tea, and black brick tea with fungal growth were orally administered with hyperuricemic mice for 14days. Serum uric acid levels, liver xanthine oxidase (XOD) and adenosine deaminase (ADA) activities, and expression of renal urate transporters and inflammatory response were detected. Compared to the model group, both types of black tea lowered serum uric acid by decreasing the uric acid production with inhibiting the activities of XOD and ADA, and increasing uric acid excretion because of downregulating urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) expressions, and upregulating organic anion transporter 1 (OAT1), organic anion transporter 3 (OAT3), and organic cation transporter 1 (OCT1) expressions. They could also improve renal injury by suppressing the activation of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome, and nuclear factor-κB (NF-κB) signaling, thereby reducing renal proinflammatory cytokine levels. Compared with black tea, black brick tea with fungal growth with a higher content of theabrownins had a better effect on lowering serum uric acid. PRACTICAL APPLICATIONS: Black tea accounts for approximately 78% of the total consumed tea in the world. Black brick tea with fungal growth is a new kind of black tea product with different sensory qualities and is suitable for storage. The study found that black brick tea with fungal growth is superior to black tea in reducing serum uric acid levels, which make a significant contribution to promote people's health and stimulate the production and consumption of black brick tea with fungal growth. In addition, it provides a clue for future research to identify the effective components of black brick tea with fungal growth lowering uric acid.

Black tea is more effective than green tea in prevention of radiation-induced oxidative stress in the aorta of rats

In the work, the effect of black tea on oxidative stress induced in the aorta by irradiation was studied. The efficiency of black and green tea types was compared, and the effect of the main green tea components (−)-epigallocatechin galate (EGCG) and (−)-epigallocatechin (EGC) on the aorta was studied. The activity of ACE in rat aorta segments was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine, and the production of ROS was estimated from the oxidation of dichlorodihydrofluorescein. Black tea prevented the radiation-induced activation of the ACE and suppressed increased ROS production in the aorta of irradiated rats. The IC50 value for the suppression of the irradiation-induced increase in ACE activity is 1 ml of black tea brewed at a rate of 0.17 g/100 ml. Black tea is 12 times more effective than green tea. The administration of both catechin derivatives from green tea to rats leads to an increase in the activity of ACE and the formation of ROS in the aorta. The dose that provided half maximum activation of ACE (EC50) on intraperitoneal (i. p.) injection of galloylated catechins was found to be the same, 0.06–0.07 μg/kg of body weight. Upon intragastric gavage of EGCG, the EC50 value was by one order of magnitude higher, 0.8 μg/kg. Black tea was more effective than green tea in prevention a radiation-induced increase of ACE activity and oxidative stress in the aorta. This difference was explained by a low content of galloylated catechins in black tea.

Effect of Black Tea (Camellia sinensis) Extract on Thyroid Physiology During Pregnancy in Experimental Animal Model

Effect of Black Tea (Camellia sinensis) Extract on Thyroid Physiology During Pregnancy in Experimental Animal Model

Comparative evaluation of the effect of black and green tea on artificially demineralized permanent enamel: in vitro study

ABSTRACT Purpose: To evaluate and compare the effect of black and green tea on initial enamel caries like lesions of extracted human permanent teeth through microhardness analysis and polarized light microscopic evaluation. Materials and methods: Fifty extracted young premolars with a standardized window on enamel were immersed in a demineralizing solution for 48 hours to produce subsurface enamel lesions. They were divided into two groups according to the type of treatment (n= 25), group I: teeth were treated by black tea infusion; group II: teeth were treated by green tea infusion. The enamel surface microhardness was measured at baseline, after the incipient enamel lesion, and after treatment. Additional twenty young premolars were selected and prepared for evaluation of the changes in enamel birefringence using the polarized light microscope. Results: Both groups showed a statistically significant increase in enamel surface microhardness after treatment as compared to the demineralization phase. By comparing the two groups, there was a statistically significant difference in the percentage of surface microhardness recovery after treatment in favor of the black tea group (P <0.0001). The polarized light microscope showed an increase in the negative enamel birefringence in both groups with less degree in the green tea group. Conclusion: Both black and green tea have a remineralizing effect on the initial enamel caries lesions with better effect of the black tea. Keywords: Initial enamel lesions, Black tea, Green tea, Microhardness, Polarized light microscope.

Therapeutic Effects of Black Tea on Micronuclei (Oral Cancer Biomarker) Induced by Betel Quid: A Mini Review

Therapeutic Effects of Black Tea on Micronuclei (Oral Cancer Biomarker) Induced by Betel Quid: A Mini Review

Black tea benefits short-chain fatty acid producers but inhibits genus Lactobacillus in the gut of healthy Sprague-Dawley rats.

The gut microbiota plays important roles in physiological and pathological processes of the host. The effect of black tea on the gut microbiota of healthy individuals remains unclear. Healthy Sprague-Dawley (SD) rats were given black tea for 4 weeks, and cecum content, serum, intestinal, and hepatic samples were collected. The results showed that black tea increased α-diversity and modulated β-diversity of the gut microbiota. Additionally, black tea enriched several short-chain fatty acid (SCFA) producers but suppressed genus Lactobacillus. Further tests revealed that the enrichment of SCFA producers was associated with a decrease in the oxidative stress of cecum content caused by black tea, and related to increased luminal butyric acid levels and enhanced intestinal barrier function. The suppression of genus Lactobacillus was related to the increase in luminal total bile acids caused by black tea. In vitro tests showed that bile acids rather than black tea directly inhibited Lactobacillus strains. The reduction in genus Lactobacillus did not affect the effects of black tea on intestinal barrier function and lipid levels. Our results imply that the effects of black tea on gut microbiota in healthy individuals are complex and provide a new perspective on the associations among black tea, gut microbiota, and health. © 2020 Society of Chemical Industry.

A Prospective, Randomised, Controlled Study on the Effect of Black Tea on Newly Detected Type 2 Diabetes

A Prospective, Randomised, Controlled Study on the Effect of Black Tea on Newly Detected Type 2 Diabetes

Effect of black tea and matrix metalloproteinase inhibitors on eroded dentin in situ.

Purpose of this in situ study was to evaluate the surface properties of eroded dentin specimens activated with three different matrix metalloproteinase (MMP) inhibitors (chlorhexidine [CHX], fluoride, green tea), black tea, and water. One hundred eighty dentin samples were prepared from extracted third molars and then samples divided into six groups. Ten volunteers were carried three specimens of each group, on acrylic palatal appliances, which were fabricated exactly for them (n = 3). Erosive cycles were done by immersing appliances in cup containing Cola and was followed by rinsing with test solutions. Microhardness values were measured. Surface properties were investigated by atomic force microscopy (AFM). Lowest change in microhardness was shown in fluoride group whereas negative control group (water) had the highest change. There were no statistically significant differences among surface roughness changes (p > .05). The least change in microhardness was seen in the fluoride group (13.05 ± 8.07), while the control group showed the highest change (33.80 ± 12.42) and was statistically significant when compared to other groups (p < .05). Besides lowest depth, values were shown in fluoride group as well. AFM evaluations showed macromolecular deposits on surfaces of fluoride, CHX, and black tea groups. No superior results were detected in CHX + fluoride group and black tea showed similar surface characteristics as green tea. Mouthrinses containing not only green tea but also black tea could be beneficial for patients with exposed dentin surfaces. Catechines and theaflavins in teas could be useful for improving surface quality.

Green tea and black tea inhibit proliferation and migration of HepG2 cells via the PI3K/Akt and MMPs signalling pathway

Background and aimsBlack tea and green tea were produced via different processing techniques from the same tea leave variety. Then, biochemical components of the two water extracts were analysed to study cell apoptosis, migration and invasion of HepG2 cells induced by black tea and green tea. MethodThe monomer components of the black tea and green tea extracts were analysed by colorimetry and HPLC, with MTT assay and colony formation assays used to assess cell proliferation and viability. The effects of black tea and green tea on apoptosis of HepG2 cells were verified by flow cytometry, with wound healing and Transwell experiments used to detect cell invasion and metastasis. The expression of PI3K/Akt signalling and apoptosis-related proteins as well as epithelial-mesenchymal transition (EMT) regulatory factor in HepG2 cells were determined by western blotting after black tea and green tea treatment. Results and conclusionsBlack tea and green tea extracts demonstrated different degrees of inhibition of cell migration and invasion, with green tea inducing more HepG2 cell apoptosis. In addition, green tea and black tea extracts inhibited the growth of HepG2 cells and induced apoptosis via PI3K/Akt, and inhibited cell migration and invasion through the MMPs signalling pathway. This study revealed the effects of fermented (black tea) and non-fermented tea (green tea) on liver cancer cells, providing a basis for the investigation of tea extracts for their anti-tumour potential.

Effect of Black Tea and Green Tea on the Radial Pulse Spectrum in Healthy Humans.

The consumption of black tea and green tea has been shown to be beneficial for cardiovascular health. Because the chemical composition of the two teas varies widely, the purpose of the study was to investigate whether the consumption of green tea and black tea had different effects on the arterial system. Thirty-three healthy subjects received a single dose of green tea (dose = 0.05 g/kg) and black tea (dose = 0.05 g/kg) in different weeks. Radial blood pressure and radial pulse pressure were measured before and after drinking tea. The harmonic analysis was performed on radial pressure waves, and harmonics (Cns) were recorded. The results showed that both black tea and green tea consumption significantly increased the C1, C2, C6, C7, C8, C9, and C10 of the radial pressure wave. Furthermore, the results confirmed that the consumption effect of green tea on C6-C10 increase is greater than that of black tea. This report also found a subtle difference that consumption of green tea increased C4, whereas consumption of black tea increased C3. We concluded that black tea and green tea have similar patterns in higher harmonics, but with varying degrees.

No Effects of Black Tea on Cognitive Decline Among Older US Men: A Prospective Cohort Study.

Accumulating evidence supports the neuroprotective effects of bioactive compounds from tea leaves. There are limited data from black tea consumption populations. To determine whether black tea consumption is associated with cognitive decline among older men. We chose to study the association between black tea consumption and cognition using data from the Osteoporotic Fractures in Men (MrOS) cohort, which collected information on tea consumption at baseline and has repeatedly assessed cognitive function in 3,844 men aged 65+ years (mean = 72.4 years). We defined tea drinkers as those who drank black tea at least once per week and further grouped them into weekly drinkers and daily drinkers. Cognitive function was assessed at baseline and approximately 7 years later using the Modified Mini-Mental State Examination (3MSE). Multivariable logistic regression and linear regression models were constructed to assess the association between black tea consumption and risk of fast cognitive decline as a binary variable and change in 3MSE scores as continuous variable. Fast cognitive decline was defined as decline in 3MSE >1.5 standard deviation of mean change score. Models were adjusted for age, education level, and baseline cognitive scores. Weekly and daily black tea drinkers were 24.8% and 12.4% of the study cohort, respectively. Fast cognitive decline occurred in 243 (6.3%) participants. Tea consumption was not associated with risk of cognitive decline, nor was tea associated with cognitive decline measured by absolute change in 3MSE scores. There was no association of black tea consumption and cognitive decline among older men in the US.

Black tea and improvement of attention: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No1924/2006.

Following an application from Unilever NV, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Ireland, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to black tea and improvement of attention. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. The food proposed by the applicant as the subject of the health claim is black tea. The Panel considers that black tea characterised by its content of tea solids, caffeine and l‐theanine, which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect. The claimed effect proposed by the applicant is ‘improves attention’. The Panel considers that improvement of attention is a beneficial physiological effect. Three human intervention studies provided by the applicant show an effect of black tea on attention under the conditions of used proposed by the applicant. The applicant proposed that the claimed effect depends on the concerted action of two substances, caffeine and l‐theanine, both of which are present in black tea. The Panel considers that the effect of black tea on attention observed in the three human intervention studies provided by the applicant can be explained by its caffeine content. The Panel concludes that a cause and effect relationship has been established between the consumption of black tea and improvement of attention. The Panel considers that the effect of black tea on attention can be explained by its caffeine content. The following wording reflects the scientific evidence: ‘Owing to its caffeine content, black tea improves attention’. In order to obtain the claimed effect, 2–3 servings of black tea providing at least 75 mg of caffeine in total should be consumed within 90 min.

The effect of black tea on human cognitive performance in a cognitive test battery

BackgroundBlack Tea is a widely consumed drink in the world. Evidence suggest Black Tea has stimulatory effect on humans. We investigated the effect of Black Tea on cognition using a cognitive test battery.MethodsParticipants (n = 32) were fasted overnight for 10 h and restrained from caffeine and other stimulant drugs for 14 days prior to participation. We randomly assigned participants into either an experimental (n = 16) or a control (n = 16) group. Experimental group consumed 250 ml of Black Tea (BT) while control group was received equal volume of water (W). Participants were tested on the following cognitive tasks: executive function, sustained attention, memory (memory span, immediate, delayed, working memory) and arithmetic calculation task.ResultsWe found that BT group performed significantly (p < 0.05) faster in the executive function task (BT: M = 1671, SD = 319; W: M = 1935, SD = 372); simple reaction time task (BT: M = 333, SD = 87; W: M = 361, SD = 101), identification of target location in the visual search task (BT: M = 925, SD = 50; W: M = 972, SD = 115). We also showed that BT group forgotten significantly (p < 0.05) lower number of words in the delayed memory recall test (BT: M = 1.12, SD = 0.15; W: M = 1.37, SD = 0.33) and made significantly (p < 0.05) fewer errors in the trail making task (BT: M = 0.31, SD = 1.01; W: M = 1.31, SD = 1.66).ConclusionsBT consumption speeded the performance, improved memory, reduced number of errors in the various cognitive tasks. Our results further showed that even in small volume of BT consumption can speed up cognitive processing.

Abstract B14: Modulating effects of green and black tea on biomarkers of chronic inflammation by gender and smoking status

Abstract Background/Purpose: Epidemiologic data implies that there are gender differences in lung cancer pathogenesis and possibly increased susceptibility to lung cancer in women. Chronic inflammation has been implicated as important modulator of human health by playing a significant role in both disease prevention and disease development. Several studies have demonstrated increased interleukin 6 (IL-6) and C-reactive protein (CRP) in the blood of smokers. The overall goal of this study was to develop a feasible tea intervention that will serve as a model for the chemoprevention of a wide range of tobacco-related diseases. Our immediate goal, that was addressed over a 4-year study period, was to determine the effects of high tea consumption on biological markers of chronic inflammation that mediate lung cancer risk, including, IL-6, CRP and antioxidant enzyme activities. Methods: We completed a 6-month randomized, controlled, double-blinded trial in a group of current and former smokers. Participants were stratified on smoking status and gender, and were randomized to green or black tea preparations or a control intervention (matching placebo). Levels of urinary iIL-6 and CRP are used to measure chronic inflammation and levels of superoxide dismutase (SOD) in red blood cells are used to measure antioxidant enzymes. Results: The study protocol was approved by all parties. A total of 138 participants (78 females and 60 males) completed the study. Our data show that il6 is significantly correlated with years of smoking and pack/year among smokers and former smokers. At the end of the 6-month intervention, female smokers in the green tea group showed a significant decrease in IL-6 (P=0.036) while male former smokers in the black tea group showed a significant decrease in CRP levels (P=0.012). There were no significant changes in dietary and serum antioxidant levels between the different groups. Conclusion: This data implies that smokers are more likely to benefit from green tea intake while the beneficial effects of black tea are observed among former smokers. Note: This abstract was not presented at the conference. Citation Format: Iman A. Hakim, Sami A. Aldaham, Janet Foote, H-H Sherry Chow. Modulating effects of green and black tea on biomarkers of chronic inflammation by gender and smoking status. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr B14.

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Effect of black tea on antioxidant, textural, and sensory properties of Chinese steamed bread

Black tea is rich in phenolic antioxidants and has various health benefits. Chinese steamed bread (CSB) is a traditional food produced through steaming of fermented dough. Black tea extracts were incorporated into northern style CSB formulation at varying concentrations up to 175mg gallic acid equivalent/gram of wheat flour. Gelatinization properties of wheat flour were not affected by the black tea addition. Rheological analysis of wheat flour showed that black tea increased pasting viscosity, consistency index of flow curves, and storage modulus (G′) and loss modulus (G″) during dynamic oscillation. Black tea incorporation increased the antioxidant activity as measured by chemical assays, had little effect on textural properties, and increased the darkness of CSB. Sensory evaluation showed a good overall acceptance of black tea fortified CSB.

Effect of Black Tea and Black Tea Pomace Polyphenols on α-Glucosidase and α-Amylase Inhibition, Relevant to Type 2 Diabetes Prevention.

This study evaluates the potential mechanism of action and bioactivity of black tea and black tea pomace for type 2 diabetes prevention via inhibition of carbohydrate hydrolyzing enzymes. Black tea leaves were extracted in hot water and black tea pomace was extracted in 70% acetone. The phenolic content of the water extract (WBT) and pomace acetone extracts (AOBT) were 5.77 and 8.9 mg/mL, respectively, both based on the same concentration of solid tea in the extract. The water extract was subjected to C18 extraction and the resulting hydrophobic fraction (HBBT) was further subjected to LH-20 extraction to recover a low molecular weight phenolic enriched fraction (LMW) and a high molecular weight enriched fraction (HMW). The phenolic content of the LMW and HMW fraction were 1.42 and 2.66 mg/mL, respectively. Among water extracts the HMW fraction was most bioactive against α-glucosidase (IC50 = 8.97 μg/mL) followed by HBBT fraction (IC50 = 14.83 μg/mL). However, the HBBT fraction was the most bioactive fraction against α-amylase (IC50 = 0.049 mg/mL). The black tea pomace (AOBT) had significant α-glucosidase inhibitory activity (IC50 = 14.72 μg/mL) but lower α-amylase inhibitory activity (IC50 = 0.21 mg/mL). The phenolic profiles for LMW and HMW fractions were evaluated using HPLC and the differences between the two profiles were identified. Further research is underway to identify and evaluate the phenolic compounds that are present in the HMW fraction. Our findings suggest that black tea and black tea pomace has potential for carbohydrate hydrolyzing enzyme inhibition and this activity depends on high molecular weight phenolic compounds.

Green Tea, Black Tea, and Oolong Tea Polyphenols Reduce Visceral Fat and Inflammation in Mice Fed High-Fat, High-Sucrose Obesogenic Diets

Green tea (GT) and caffeine in combination were shown to increase energy expenditure and fat oxidation, but less is known about the effects of black tea (BT) and oolong tea (OT). This study investigated whether decaffeinated polyphenol extracts from GT, BT, and OT decrease body fat and inflammation in male C57BL/6J mice fed high-fat/high-sucrose [HF/HS (32% energy from fat, 25% energy from sucrose)] diets. Mice were fed either an HF/HS diet with 0.25% of polyphenol from GT, OT, or BT or a low-fat/high-sucrose [LF/HS (10.6% energy from fat, 25% energy from sucrose)] diet for 20 wk. Monomeric tea polyphenols were found in the liver and adipose tissue of mice fed the HF/HS diet with GT polyphenols (GTPs) and OT polyphenols (OTPs) but not BT polyphenols (BTPs). Treatment with GTPs, OTPs, BTPs, and an LF/HS diet led to significantly lower body weight, total visceral fat volume by MRI, and liver lipid weight compared with mice in the HF/HS control group. Only GTPs reduced food intake significantly by ∼10%. GTP, BTP, and LF/HS-diet treatments significantly reduced serum monocyte chemotactic protein-1 (MCP-1) compared with HF/HS controls. In mesenteric fat, monocyte chemotactic protein-1 (Mcp1) gene expression was significantly decreased by treatment with GTPs, BTPs, OTPs, and an LF/HS diet and in liver tissue by GTP and BTP treatments. Mcp1 gene expression in epididymal fat was significantly decreased by the BTP and LF/HS diet interventions. In epididymal fat, consistent with an anti-inflammatory effect, adiponectin gene expression was significantly increased by GTPs and OTPs. Angiogenesis during adipose tissue expansion is anti-inflammatory by maintaining adipocyte perfusion. We observed significantly increased gene expression of vascular endothelial growth factor A by GTPs and vascular endothelial growth factor receptor 2 by BTPs and the LF/HS diet and a decrease in pigment epithelium-derived factor gene expression by OTPs and BTPs. In summary, all 3 tea polyphenol extracts induced weight loss and anti-inflammatory and angiogenic effects, although the tissue content of polyphenols differed significantly.

The effect of black tea on blood pressure: a systematic review with meta-analysis of randomized controlled trials.

ObjectiveEpidemiological evidence has linked consumption of black tea, produced from Camellia sinensis, with a reduced risk of cardiovascular diseases. However, intervention studies on the effects of tea consumption on blood pressure (BP) have reported inconsistent results. Our objective was to conduct a systematic literature review with meta-analysis of controlled human intervention studies examining the effect of tea consumption on BP.MethodsWe systematically searched Medline, Biosis, Chemical s and EMBASE databases through July 2013. For inclusion, studies had to meet the following pre-defined criteria: 1) placebo controlled design in human adults, 2) minimum of 1 week black tea consumption as the sole intervention, 3) reported effects on systolic BP (SBP) or diastolic BP (DBP) or both. A random effects model was used to calculate the pooled overall effect of black tea on BP.ResultsEleven studies (12 intervention arms, 378 subjects, dose of 4–5 cups of tea) met our inclusion criteria. The pooled mean effect of regular tea ingestion was −1.8 mmHg (95% CI: −2.8, −0.7; P = 0.0013) for SBP and −1.3 mmHg (95% CI: −1.8, −0.8; P<0.0001) for DBP. In covariate analyses, we found that the method of tea preparation (tea extract powders versus leaf tea), baseline SBP and DBP, and the quality score of the study affected the effect size of the tea intervention (all P<0.05). No evidence of publication bias could be detected.ConclusionsOur meta-analysis indicates that regular consumption of black tea can reduce BP. Although the effect is small, such effects could be important for cardiovascular health at population level.

Effects of black tea on body composition and metabolic outcomes related to cardiovascular disease risk: a randomized controlled trial.

There is increasing evidence that tea and its non-caffeine components (primarily flavonoids) contribute to cardiovascular health. Randomized controlled trials have shown that tea can improve cardiovascular disease risk factors. We have previously reported a non-caffeine associated beneficial effect of regular black tea consumption on blood pressure and its variation. To explore the non-caffeine associated effects of black tea on body weight and body fat distribution, and cardiovascular disease related metabolic outcomes. regular tea-drinking men and women (n = 111; BMI 20-35 kg m(-2)) were recruited to a randomized controlled double-blind 6 month parallel-designed trial. Participants consumed 3 cups per day of either powdered black tea solids (tea) or a flavonoid-free flavour- and caffeine-matched placebo (control). Body weight, waist- and hip-circumference, endothelial function and plasma biomarkers were assessed at baseline, 3 months and 6 months. Compared to control, regular ingestion of black tea over 3 months inhibited weight gain (-0.64 kg, p = 0.047) and reduced waist circumference (-1.88 cm, P = 0.035) and waist-to-hip ratio (-0.03, P = 0.005). These effects were no longer significant at 6 months. There were no significant effects observed on fasting glucose, insulin, plasma lipids or endothelial function. Our study suggests that short-term regular ingestion of black tea over 3 months can improve body weight and body fat distribution, compared to a caffeine-matched control beverage. However, there was no evidence that these effects were sustained beyond 3 months.