Brewed Tea Research Articles

The Effect of Green Tea (Camellia Sinensis L) Steeping on Blood Glucose Levels of Mice

Diabetes mellitus (DM) is a chronic metabolic disorder caused by high blood sugar levels due to lack of insulin function. Insulin is a hormone that helps blood sugar enter. Insulin injections are the main therapy for treating diabetes mellitus, they are relatively expensive and long-term use can cause side effects such as hypoglycemia. Other alternatives need to be found for the treatment of Diabetes Mellitus (DM), one of which is green tea. The aim of this research was to determine the effect of steeping green tea on the blood glucose levels of mice (24 males) which were divided into 4 groups. Mice were selected using the Simple Random Sampling technique representing 4 dose groups, namely: control group, brewed green tea at a dose of 30mg/0.5cc/day, brewed green tea at a dose of 35mg/0.5cc/day and green tea. brew at a dose of 40mg/0.5cc/day. The treatment was given orally for 6 repetitions. For 15 consecutive days. Data analysis used the One ANOVA test with a significance level of 5% (p<0.05) followed by the LSD test with a confidence level of 95%. The results of the study showed that there was a significant effect on reducing glucose levels in mice. Mice given a dose of 30, 40 and 45% brewed green tea experienced a decrease in glucose levels of 43, 32 and 40.27% respectively compared to controls.

PHYTOCHEMICAL SCREENING AND ANTIOXIDANT ACTIVITY FROM STEEPING HERBAL TEA COMBINATION FIG LEAF (Ficus carica L.) AND SUNGKAI LEAF (Paronema canesescens Jack)

Herbal tea is made from a mixture or single form of leaf, seeds, or roots of various types of plants that have properties in help treatment. The combination of Ficus carica (fig) leaf and Peronema canescens Jack (sungkai) leaf is one of the innovative ingredients that can be used in herbal teas. This study aims to determine the antioxidant and hedonic activity of herbal tea steeping a combination of fig leaf, sungkai leaf, and their combinations with various weight variations, namely (70:30), (50:50), (30:70). Antioxidant activity was tested using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, then analyzed using a UV-Visible Spectrophotometer. To find out the level of consumer preference for herbal tea brewing, a hedonic test was carried out. From the antioxidant activity test, the IC50 values of fig leaf, sungkai leaf, and the combination were 25.4885, 30.7039, 18.0717, 21.0907, and 25.0547 µg/mL respectively. Hedonic tests were performed on panelists and analyzed using the Friedman test results obtained p-value>0.05. It can be concluded that all formulas have very strong antioxidant activity, and there is no significant effect between the 5 formulas on the color, smell, and taste of the brew.

Reducing microplastics in tea infusions released from filter bags by pre-washing method: Quantitative evidences based on Raman imaging and Py-GC/MS

Microplastics released from plastic-based filter bags during tea brewing have attracted widespread attention. Laser confocal micro-Raman and direct classical least squares were used to identify and estimate micron-sized microplastics. Characteristic peaks from pyrolysis-gas chromatography/mass spectrometry of polyethylene terephthalate, polypropylene, and nylon 6 were selected to construct curves for quantification submicron-sized microplastics. The results showed that microplastics released from tea bags in the tea infusions ranged from 80 to 1288 pieces (micron-sized) and 0 to 63.755 μg (submicron-sized) per filter bag. Nylon 6 woven tea bags released far fewer microplastics than nonwoven filter bags. In particular, a simple strategy of three pre-washes with room temperature water significantly reduced microplastic residues with removal rates of 76 %–94 % (micron-sized) and 80 %–87 % (submicron-sized), respectively. The developed assay can be used for the quantitative evaluation of microplastics in tea infusions, and the pre-washing reduced the risk of human exposure to microplastics during tea consumption.

Consumer perception of decocted coffee leaf tea originated from different altitude

It is commonly known that plantation location influences the composition of the coffee component as well as the leaves. Therefore, it was expected that the difference location will also affect the quality of decocted one. In this current study, effect of plantation location is investigated on Arabica and Robusta coffee leaf tea. Two different coffee plantations were chosen as the region of observation (560 ASL and 1700 ASL). All the coffee leaf tea was brewed by decoction method, in which sensorially optimized by Just about Right (JAR) method. The sensory attributes of concern were included sweet, sour, bitter taste and astringent mouth-feel. Considering consumer preference on the brewed coffee leaf tea, the decoction brewing condition were set on 95°C for 5 minutes. Additionally, coffee leaf tea grown at higher altitudes exhibits significantly greater total phenolic content (TPC) and antioxidant activity (p < 0.05). Not only does this tea have higher TPC and antioxidant activity at higher altitudes, but it also shows superior consumer sensory acceptability. This may be supported by the fact that higher altitude coffee leaf tea has more diverse sensory driver components than that of lower altitude coffee leaf tea as suggested by LC-MS.

A case study on the rotomolding behavior of black tea waste and bio-based high-density polyethylene composites: Do active compounds in the filler degrade during processing?

This study verified the possibility of using waste material from the food industry (black tea) as functional filler of rotomolded biobased high-density polyethylene-based composites. As part of the experimental work, the influence of the materials preparation, i.e., dry blending versus twin-screw extrusion, on the effectiveness of the stabilizing antioxidant effect of the black tea was analyzed. The aim of the work was to verify whether, despite the initial degradation of the structure of the lignocellulosic filler, it would be possible to keep its antioxidant capacity and the stabilizing effect on the polyethylene matrix. The research showed that the filler allowed to stabilize the polymeric matrix during the rotomolding process, despite the appearance of numerous defects in the form of pores and a reduction in mechanical properties, more significant for composites prepared by dry blending, obtaining elastic modulus drops of about 50 %. Furthermore, the pre-processing step by melt mixing results in a significant improvement of the composite's thermo-oxidation stability, with increases in the oxidation induction time (OIT), from 25 min for the HDPE to over 70 min for composites with 5 % black tea, and improved rheological behavior, preventing the crosslinking of the matrix, indicative of its thermo-oxidative degradation. The tea brewing process caused the decrease of antioxidant activity of the filler; however, it did not significantly affect the antioxidant behavior, maintaining its influence on the polymeric matrix when the material is prepared via twin-screw compounding, which was proved to provide better stability, increasing OIT by approximately 20 min later when compared to dry blending.

Bilayer fiber membrane electrospun from polylactic acid/alginate/bromelain and polylactic acid for enhancing the functionality of tea bags

Tea bags have been extensively used in the food industry and daily life as an efficient way to pack tea. However, the large pores of the commercial tea bags not only lead to the inner contents of tea bag susceptible to bacteria and moisture but also result in the faster water infusion which is undesired during tea brewing. In this study, the polylactic acid (PLA)-PLA/sodium alginate (SA)/bromelain (BL) bilayer fiber membrane imitating the asymmetric wetting structure of lotus leaf blades was fabricated to avoid the above disadvantages of commercial tea bag. The PLA/SA/BL skin-core nanofiber membrane which imitating the skin-core structure of lotus leaf stems was first prepared as the hydrophilic and support layer, then a hydrophobic PLA layer was deposited on top via electrospinning. The PLA-PLA/SA/BL bilayer fiber membrane had a breaking strength of 5.5 MPa and started to decompose at 260 °C. Using this bilayer membrane, tea bags were designed with a novel structure where the hydrophobic PLA layer was placed in the same direction. The novel structure endow the those tea bags a slow and directional water transfer property. Therefore, the PLA-PLA/SA/BL bilayer fiber membrane has great potential for applications as tea bags.

First ATR-FTIR Characterization of Black, Green and White Teas (Camellia sinensis) from European Tea Gardens: A PCA Analysis to Differentiate Leaves from the In-Cup Infusion.

ATR-FTIR (Attenuated Total Reflectance Fourier Transform InfraRed) spectroscopy, combined with chemometric, represents a rapid and reliable approach to obtain information about the macromolecular composition of food and plant materials. With a single measurement, the chemical fingerprint of the analyzed sample is rapidly obtained. Hence, this technique was used for investigating 13 differently processed tea leaves (green, black and white) all grown and processed in European tea gardens, and their vacuum-dried tea brews, prepared using both hot and cold water, to observe how the components differ from tea leaf to the in-cup infusion. Spectra were collected in the 1800-600 cm-1 region and were submitted to Principal Component Analysis (PCA). The comparison of the spectral profiles of leaves and hot and cold infusions of tea from the same country, emphasizes how they differ in relation to the different spectral regions. Differences were also noted among the different countries. Furthermore, the changes observed (e.g., at ~1340 cm-1) due to catechin content, confirm the antioxidant properties of these teas. Overall, this experimental approach could be relevant for rapid analysis of various tea types and could pave the way for the industrial discrimination of teas and of their health properties without the need of time-consuming, lab chemical assays.

Tea Constituent in Protecting Glyphosate Effect on Human Breast Cancers Cells (MCF-7) Growth

Glyphosate, which has been documented as a contaminant in tea, promotes the proliferation of human breast cancer cells (MCF-7). Tea, on the other hand, includes various antioxidants, including epigallocatechin gallate (EGCG), which may protect against cancer cell proliferation. The purpose of this research is to determine the preventive effect of concentrated brewed green tea on MCF-7 development caused by glyphosate. The glyphosate concentration that promotes MCF-7 development was determined using a serial concentration of glyphosate. Glyphosate concentrations of up to 64 mg/L were shown to have no effect on MCF-7 cell proliferation. Concentrated brewed tea and EGCG 200 mg/L have the potential to suppress MCF-7 cell proliferation in the presence of glyphosate up to 512 mg/L. The combination of glyphosate and concentrated brewed tea or EGCG protects against glyphosate toxicity via altering the expression of tumor suppressor protein (p53).

Unexpected hydroxyl radical production in brewed tea under sunlight.

Tea is one of the world's most popular and widely consumed beverages. It is a common pastime to enjoy a cup of tea in the sunshine. However, little attention has been given to understanding the possible photochemical reactions occurring beneath the calm surface of brewed tea. Epigallocatechin gallate (EGCG), which is widely used in food and beverages, is the most significant active ingredient found in tea. In this study, we investigated the presence of free radicals in both an aqueous EGCG solution and brewed tea under simulated sunlight conditions. To our surprise, we unexpectedly observed the production of hydroxyl radicals (•OH) in brewed tea. It was found that sunlight irradiation played a critical role in the formation of •OH, independent of the presence of metal ions. Furthermore, we demonstrated that the •OH generated from the EGCG aqueous solution induced cell cytotoxicity and DNA damage in vitro. Considering the crucial role of •OH in various fields, including human health and the environment, it is important to further explore the practical implications of •OH production in brewed tea under sunlight. In summary, our study unveils the unexpected formation of •OH in brewed tea and emphasizes the significance of sunlight-induced reactions. The observed cytotoxic and DNA-damaging effects of •OH emphasize the importance of understanding the potential health consequences associated with tea consumption. Further research in this area will contribute to a better understanding of the broader implications of •OH production in brewed tea under sunlight.

Eisenia fetida'nın İstiridye Mantarı Atığı ve Demlenmiş Çay Atığı ile beslenmesinin vermikomposttaki gelişimi ve bazı besin maddeleri üzerine etkilerinin belirlenmesi

Recycling of domestic wastes into products with economic value can provide great benefits to environmental protection and sustainable environmental management. The aim of this study is to determine the effects of feeding Eisenia fetida with oyster mushroom waste and brewed tea waste on the growth it and some nutrients in fertilizer. For this ppurpose, three different growing media including Oyster mushroom waste (100%) (T1), Oyster mushroom waste (50%) + 50% brewed tea waste (50%) (T2), Oyster mushroom waste (25%) + (75%) (T3) brewed tea waste were used in the experiments. The research was carried out in plastic containers with a width of 40 cm x 40 cm length x 20 cm in accordance with the randomized plot design in three repetitions. The changes of some nutrients in solid and liquid vermicompost obtained from different quality nutrient media were made by Anova and Variance analysis and multiple comparisons between the nutrient media were made by Duncan test. As a result of the study, the number of worms in all growing media decreased over time. The highest reduction was 31.10% in oyster mushroom media (25%) + brewed tea waste (75%) in the nutrient medium. As a result of the study, the highest Ca, Na, K, Mg values were found in untreated Oyster mushroom (control) waste, while the highest Fe value was found in solid vermicompost obtained from oyster mushrooms (100%) in T1. The highest Zn value was obtained from solid vermicompost obtained from the mixture of OM (50%) + BTW (50%) in treatment T2. The highest Cu and Mn values were found in the solid vermicompost obtained from the OM (25%) +BTW (75%) mixture in T3, and the changes were statistically significant. The highest Ca, Mg, Na, Cu, Zn, and K values in vermiwash obtained from different nutrient media were found in liquid vermicompost produced from OM (100%) (T4). The highest Mn values were found in T5, while the highest Fe was found in T6. It was determined that the changes in Ca, Zn, Mn and Mg values in liquid vermicompost obtained from different media were statistically significant (P

Pengaruh Pemberian Seduhan Teh Hijau (Camellia Sinensis) Terhadap Kadar Glukosa Darah dan Malondialdehide (MDA)

Oxidative stress is a condition where there is an imbalance between oxidants and antioxidants in the body which can trigger psychological stress. Oxidative stress can be reduced by consuming exogenous antioxidants (antioxidants from outside), where green tea is thought to be able to reduce oxidative stress. The aim of this study was to examine the effect of steeping green tea on blood glucose and Malondialdehyde (MDA) levels in male Wistar Strain white rats exposed to psychological stress. The design used in this research was Randomized Post Test Only Group Design. There were 5 groups of mice; 2 are a normal control group and a stress control group, and 3 treatment groups. Previously, the mice were given psychological stress 1 x 24 hours in the form of disturbed sleep patterns, so that the experimental animals experienced oxidative stress, then green tea was given to the treatment group with a single dose of 3.6 ml/head in the 1st hour in the group. treatment 1, 6th hour in treatment group 2, and 24th hour in treatment group 3. Statistical analysis used the Manova test. Based on statistical analysis, it shows that there was a decrease in blood glucose and Malondialdehyde (MDA) levels in all treatment groups given exposure to psychological stress and steeping green tea. A single dose of green tea brewing in experimental animals experiencing oxidative stress was proven to be able to neutralize oxidative stress in the 1st hour after administration of green tea brewing and the antioxidant activity still lasted up to 24 hours.

EXPERTISE OF PYRAMID TEA BAGS BY OPTICAL MICROSCOPY AND FTIR-SPECTROSCOPY METHODS. MICROPLASTICS FORMATION IN BREWED TEA

Eight brands of pyramid tea bags on the Ukrainian market were studied: Sun Gardens (1), Lovare (2), Curtis for Mc Donalds (3), Curtis (4), Lipton (5), Premiya (6), Sonnet (7) and Loyd (8). Using FTIR spectroscopy, it was found that the pyramids of the bags are made of thermoplastic polymers polyethylene terephthalate (samples 1-7) and polylactic acid (sample 8). The threads attached to the pyramids are made of thermoplastic polymers polypropylene (samples 1,2,4-7), polyethylene terephthalate (sample 4) and polylactic acid (sample 8). The specific optical rotation of polylactic acid [α]D25 is about -150° (c=1, CHCl3), which refers to poly(L-lactic acid). Using optical microscopy, it was established that the structure of the pyramids are divided into those made of plain woven fabrics (samples 1-3) and heat-bonded nonwoven fabrics (samples 4-8). The tea bags (samples 1-3) exhibit a well patterned net structure (mesh) with the pores perceived to be uniform and regular. The tea bags made of nonwoven materials have an irregular network consisting of compact and random arrangement of fibers. The fibers are pleated randomly, generating irregular pores. Nonwoven fabrics are made from fibers with a diameter of 12-18 µm, woven fabrics are made from fibers with a diameter of 48-54 µm. The area density of nonwoven fabrics is 18.5-20.3 g/m2, the area density of woven fabrics is 22.0-22.7 g/m2. The threads are made by twisting several single-twisted yarns. The structure of threads are a cabled yarn from three 2-ply yarns (samples 1,8), 4-ply yarn (samples 2-4,6,7) and 4-ply multyfilament yarn (samples 5). The final twist of the plied yarn/cord is S-twist. The primary structural element of threads in the case of samples 1-4, 6-8 are staple fibers, of sample 5 are multyfilament fibers. Each empty pyramids and thread was steeped at 95oC for 5 min in 10 mL of water. It has been established that the shape of microplastic particles formed in beverages during tea brewing is determined by the primary structure of tea bags. Both pyramids and threads release irregularly shaped microplastic particles.

Smart Tea Utensil Design for Improving Beginners’ Tea Brewing Experience

In Taiwan, people who enjoy traditional Gongfu tea are becoming older and older, while the younger generation has many alternative beverages to select from. In order to sustainably pass down traditional tea-drinking culture, this study has incorporated concepts and methodologies of the peak-end rule, customer journey maps (CJMs), quality function deployment (QFD), fuzzy analytic hierarchy process (FAHP), and fuzzy comprehensive evaluation based on entropy, resulting in the development of a set of tea utensils tailored for a novice or beginner tea maker with the purpose of improving the tea-drinking experience of the younger generation. In this study, the ranking of the importance in regard to six design requirements turned out to be: enhancing the sniffing experience (0.240); having ergonomic designs that facilitate a smooth process of pouring hot water into the cup (0.205); increasing the ease of storing tea utensils after brewing (0.162); enabling users to more precisely determine the strength of the tea (0.144); increasing fun while pouring tea leaves into the teapot (0.143); and having clearly designated space for placing each tea utensil (0.107). Through the experts’ evaluation, 66.6% of them rated the design outcome as “good” or “very good”, indicating that the innovative tea utensils developed in this study can effectively satisfy users’ needs. This study can be the supplement to the innovation shortage of tea-culture-related studies, establish the research framework in the academic field, and bring more innovation and potential to the field of the tea culture.

Ultrasound-Assisted Extraction as a Technique for Preparing Improved Infusions as Functional Beverage Bases

Right after water, tea is one of the most popular beverages in the world. The composition of a tea drink is determined by, among other things: the degree of fermentation and the fineness of the tea leaves, as well as the brewing time and temperature. The purpose of this study was to verify the hypothesis that the extraction of selected elements from dried tea during infusion preparation was improved by using ultrasound under laboratory conditions. The effect of increasing the extraction time was also analyzed. The effectiveness of ultrasound was evaluated by measuring the content of selected elements in the extract of teas that were treated with ultrasound compared to a control group. The effectiveness of the application of ultrasound was evaluated by measuring the content of individual elements at intervals of 1 min, 5 min and 10 min comparing the application of ultrasound with the classical technique of tea brewing. In addition, the results were related to measurements of the amounts of overall concentrations of selected ions after the dried tea mineralization procedure. Samples of extracts and mineralizates were analyzed for elemental composition using an ICP-OES iCAP Dual 6500 Thermo® spectrometer. The use of ultrasound was shown to have a positive effect on the extraction process, and the efficiency of the process depended on the tea variety and the extraction time. The percentage of extraction relative to the results of the total amount of extracted ions was also calculated. Analyzing the effect of ultrasound on the leaching of minerals from tea leaves during infusion preparation is another step toward optimizing the tea brewing extraction process and a way to improve the nutritional value of tea infusions as a functional beverage base. The application of ultrasound in the extraction process of tea infusions may be a good solution to support traditional methods of extracting infusions for both research and technological purposes.

The effect of formulation with ginger (Zingiber officinale var. Roscoe) and different brewing techniques on physicochemical and organoleptic characteristics of cascara tea

The utilization of coffee cherry pulp, one of coffee processing waste, into tea (or known as cascara tea) is still limited regardless of its potential. Cascara tea flavor could be improved, such as by the addition of spices. Besides the addition of spices, the brewing techniques may also contribute to the properties of brewed cascara tea and consumer acceptance This study aimed to determine the effect of formulation (the ratio between cascara and ginger) and the different brewing techniques on the physicochemical and organoleptic characteristics of cascara tea. The best treatment was also determined. This study was conducted in Nested design with 2 factors i.e. brewing techniques (decoction and infusion) and ratio of cascara and ginger (9:1; 7:3; 5:5). Data analysis was performed using Minitab 17 and the best treatment was chosen by Multiple Attribute Zeleny method. The results showed that the ratio between cascara and ginger, as well as brewing techniques had a significant effect (α = 0.05) on total phenolic content, caffeine content, pH, color (L*, a* and b* value), and organoleptic parameter (except for taste, aftertaste, and overall). The best treatment was obtained from cascara tea with ratio of cascara and ginger =7: 3, brewed using the decoction technique. It offered total phenolic content of 27.73 mg GAE/g; caffeine content of 1.93 mg/g; pH of 6.1; Lightness (L*) 40.1; redness (a) 12.4; and yellowness (b*) 25.6.

Distinctive Processing Effects on Recovered Protein Isolates from Laurel (Bay) and Olive Leaves: A Comparative Study.

Although there is a well-known awareness of the nutritional potential of plant proteins, their utilization within food formulations is currently limited due to insufficient investigation of the functional properties or processing conditions. In this study, the protein contents of the remaining pulps of laurel (bay) (LL) and olive leaves (OL) after alcoholic washing (representing phenolic compound extraction), heat treatment (representing the usage of the leaves for tea brewing or as cooking aid), and deoiling process (representing oil extraction) were investigated. Bicinchoninic acid assay (BCA) indicated that the best protein yield was achieved with a direct isolation process after hexane oil removal. Both LL and OL isolates contained around 80% protein, but high temperature and alcohol content broke down the protein structure as well as decreased the final protein content (∼40%). Alcohol treatment appears to remove protein-bound phenols and increase fluorescence intensity in OL protein isolates while potentially causing structural alterations in LL proteins. In addition to a dramatic decrease in fluorescence intensity, the absolute zeta potentials of protein extracts of boiling OL and LL increased by 53 and 24%, respectively. The increased zeta potentials along with the decreased fluorescence intensity indicate the changes in the protein conformation and enhanced hydrophilicity of the protein structure, which can influence the functional properties of proteins. Protein extracts of deoiled LL had the highest ΔH value (180 mJ/mg), which is higher than other laurel and all olive protein samples. Laurel protein isolates became more thermally stable after hexane treatment. Moreover, the protein extracts after hexane treatment showed better emulsion capacity from both laurel (71.57%) and olive (61.87%). Water-binding capacity and thermal stability of the protein extracts from deoiled samples were higher than those of the other pretreatments, but the boiled samples showed higher oil-binding capacity due to protein denaturation. These findings indicate the importance of processing conditions in modulating protein properties for various applications.

Characteristics of Kawa Daun with Differences in the Drying Time and Thickness of Arabica Coffee Leaves

Kawa daun is a beverage that is typical of West Sumatra and is created from dried coffee leaves.The purpose of this study is to ascertain the water content of kawa daun powder, pH value, total dissolved solids, the hedonic test for steeping kawa daun during drying using a microwave, the thickness of the pile of Arabica coffee leaves, and the preferred brew of kawa daun tea among the panelists. This study used a completely randomized design (CRD) factorial pattern with 2 factors. Factor A drying time for 3, 7, and 11 minutes. Factor B number of piles of leaves 2, 4, 6, 8, and 10 leaves. The resulting coffee leaf powder and kawa daun brew were then tested using hedonic tests for color, aroma, and taste as well as water content, pH value, and total dissolved solids. The panelists' chosen and favorite kawa daun drink composition was dried with 10 piles of leaves for 11 minutes. The properties of coffee leaf powder include a water content of 4.11%, a pH value of 6.4, 1.3 °Brix of total dissolved solids, and hedonic scores of 4.95 (very like), 4.40 (like), and 4.80 (very like) for color, scent, and taste.

TÜRKİYE’DE DEMLENMİŞ SİYAH ÇAYIN RENK VE PARLAKLIĞININ FLORÜR KONSANTRASYONUNA ETKİSİ

Objective: The main purpose of this study is to determine the effect of the tea brewing time on the total color, brightness, and fluoride ion concentration of tea infusions in Türkiye. Material and Method: 250 ml of boiling distilled water was added to 6 g of granulated tea sample and brewed against increasing time. The total color and brightness of the tea infusions were determined by a spectrophotometer at 460 nm, while a potentiometric method was used to determine the fluoride ion concentration. Result and Discussion: We conclude that the concentration of fluoride ions and other bioactive compounds in the tea infusion is strongly dependent on the tea preparation and brewing preferences of consumers. According to our results, fluoride concentrations in tea infusions reach the plateau after 20 minutes in a Turkish way of tea brewing. Therefore, tea-brewing time is an important variable in calculating the daily fluoride intake for extreme tea-consuming populations like Türkiye.

Colour Parameters and Changes of Tea-Stained Resin Composite Exposed to Whitening Pen (In Vitro Study).

One of the crucial factors influencing the longevity of anterior aesthetic dental restorations is the colour stability of resin composites. Bleaching and whitening have become popular methods for enhancing dental aesthetics. Home whitening techniques, such as special pens, are widely available commercially. This in vitro study aimed to determine the efficiency of a whitening pen in removing tea stains from resin composite by measuring colour differences (ΔE00). Additionally, the study aimed to evaluate the variations in colour parameters measured by extra-oral and intra-oral spectrophotometers. A total of 45 disc-shaped resin composite specimens were randomly divided into three groups; Group 1: stored in artificial saliva (control), Group 2: stored in artificial saliva followed by a whitening pen application, and Group 3: stored in tea followed by a whitening pen application. Colour measurements were taken three times for each specimen using two spectrophotometers (extra-oral and intra-oral devices); T1: before storage (baseline), T2: after storage in artificial saliva or tea for 6 days; and T3: after one week of whitening pen application in groups 2 and 3. The data were statistically analyzed using one-way ANOVA followed by the Tukey post hoc test (p ≤ 0.05). The independent sample t-test was also employed. The equation of CIEDE2000 (ΔE00) was used to calculate the colour difference between the dry, as-prepared specimens (baseline), and those after storage or bleaching. The colour changes exceeding the acceptability threshold (∆E00 = 1.8) were considered unacceptable. After whitening, the colour of the specimens stored in brewed tea (Group 3) remained unacceptable, as indicated by both the extra-oral and intra-oral spectrophotometers (ΔE00 = 4 and 2.9, respectively). Groups 1 and 2 exhibited lower ΔE00 values than Group 3 (p = 0.01 *). No significant difference was observed between Group 1 (stored in artificial saliva) and Group 2 (stored in artificial saliva and then bleached) (p = 0.3). Significant differences were consistently observed between the data obtained from the extra-oral spectrophotometer and the intra-oral one. The whitening pen proved ineffective in removing tea stains from resin composites. Although significant differences were found between the values obtained by the two spectrophotometers (extra-oral and intra-oral), both devices confirmed the unacceptable colour of the tea-stained resin composites after whitening.

An Update on Impacts of Epigallocatechin Gallate Co-administration in Modulating Pharmacokinetics of Statins, calcium channel blockers and beta-blockers.

Brewed green tea, green tea extract (GTE), and its primary active compound, epigallocatechin gallate (EGCG) may interact with drugs and alter the drug's therapeutic effectiveness ultimately leading to therapeutic failure or drug overdose. Several isolated reports have claimed that EGCG is the main active ingredient that causes these effects. Several isolated reports have claimed that EGCG is the main active ingredient that causes these effects. While a few studies aimed to uncover evidence of EGCG-drug interactions, no study has thoroughly and collectively reviewed them. EGCG is a potential cardio-protective agent used by many patients with cardiovascular diseases as a complementary medicine alongside conventional modern medications, either with or without the knowledge of their physicians. Therefore, this review focuses on the impact of concurrent EGCG supplementation on pharmacokinetics and pharmacodynamics of several commonly used cardiovascular drugs (statins, beta-blockers, and calcium channel blockers). Pubmed index was searched for keywords related to this review, without year limit and the results analysed for interactions of cardiovascular drugs with EGCG. This review concludes that EGCG increases systemic circulation of several statins (simvastatin, fluvastatin, rosuvastatin,) and calcium channel blockers (verapamil), but decreases the bioavailability of beta-blockers (nadolol, atenolol, bisoprolol). Further studies on its clinical significance in affecting drug efficacy are required.