Comparative Evaluation of the Effects of Black Tea Extract Mouthrinse and Chlorhexidine Mouthwash on Salivary Streptococcus Mutans Load

Background- Dental caries is one of the most frequent oral health problems. The present study shows the antibacterial effect of black tea extract on salivary Sterptococcus Mutans load. Materials & Methods- The study was conducted on 125 individuals. The differences in the Colony Forming Units and count-scores of S.mutans were analyzed in salivary samples collected from individuals before and after administration of 2% black tea extract mouth-rinse and chlorhexidine mouthwash(CM). Results- There was a statistical difference in mean salivary S. mutans colony count and mean count- score before and after administration of black tea extract mouth-rinse (p = 0.0003) and chlorhexidine mouthwash (p = 0.0002) respectively. Hence, it was found that there is no statistically significant difference in the fall of S.mutans load due to black tea mouth-rinse and chlorhexidine mouthwash. Conclusions- A 2% black tea extract mouth-rinse significantly reduces salivary S.mutans load, irrespective of age and gender. Also, it is an effective natural anti-cariogenic agent with no known implicated side effects.

Effect of Lactobacillus coryniformis FZU63 on the flavor quality of black tea beverage / 生物工程学报

The tea beverages will be endowed with distinct aroma and taste, as well as various biologically active compounds including probiotic factors, when fermented with lactic acid bacteria (LAB). However, at present, few studies on the dynamics of flavors in tea soup at different fermentation stages were conducted. In this study, the composition of monosaccharides, aromatic components, free amino acids, and organic acids were measured, when the black tea beverages were fermented with Lactobacillus coryniformis FZU63 which was isolated from Chinese traditional kimchi. The results indicated that monosaccharides including glucose, fructose, mannose and xylose in black tea beverages are the main carbon sources for fermentation. In addition, the abundance of aromatic compounds in black tea soup are increased significantly at different fermentation stages, which endow the fermented black tea soup with fruit aroma on the basis of flowery and nutty aroma. Moreover, some bitter amino acids are reduced, whereas the content of sweet and tasty amino acids is elevated. Furthermore, the levels of lactic acid, malic acid, citric acid and other organic acids are accumulated during the fermentation. Additionally, sensory evaluation displays that black tea beverage is acquired with comprehensive high-quality after being fermented for 48 h. This study provides a theoretical basis to steer and control the flavor formation and quality of the fermented tea beverages during LAB fermentation.

Effects of Breaking up Deskwork with Physical Activity Combined with Tea Consumption on Cerebrovascular Function, Mood, and Affect

Abstract Background: Prolonged sitting, typical of desk work, decreases cerebral blood flow (CBF), mood and affect. Conversely, short physical activity breaks from sitting may prevent these detrimental effects and provide cardiometabolic benefits. Objective: We evaluated the effect of interrupting prolonged sitting with short breaks of light physical activity combined with tea consumption on CBF, cerebral autoregulation (CA), mood, and affect in desk workers. Methods: Nineteen healthy desk workers (ten male, 27±10 years) performed desk work in a laboratory for six hours on two separate intervention days: tea breaks (TEA-BREAK: short walk combined with ingestion of one cup of tea every hour) and sedentary (SED: ingestion of one cup of water every hour, while seated). Before and after desk work, we assessed mean arterial pressure (MAP), middle cerebral artery blood velocity (MCAv) and CA. Questionnaires were used to assess mood (Bond & Lader, PANAS) and affect (Affect grid) before and after the intervention. Data are expressed as mean ± standard deviation. Two-way ANOVA with repeated measurements followed by Sidak post hoc test was used for data analysis. Paired Student's t-test was also used to compare changes (Δ) between trials. Statistical significance was at p<0.05. Results: Desk work increased MAP (4.6±4.6 Δ mmHg; P<0.05), and decreased MCAv (-5.2±7.0 Δ cm/s; P<0.05), with no difference between interventions in these parameters. TEA-BREAKS, but not SED, decreased gain (-0.08±0.12 Δ cm.s−1.mmHg.−1) and increased phase (5.26±8.84 Δ radians) at very low frequency (P<0.05), but not at low frequency. Small changes in positive affect were found after the six hours of desk work (-5.5±7.3 Δ scale; P<0.05), with no differences between interventions. Conclusion: Changes in MCAv and positive affect induced by prolonged desk work could not be prevented by TEA-BREAKS. However, TEA-BREAKS improved CA, suggesting a higher efficiency in maintaining MCAv in response to blood pressure fluctuations.

Comparative evaluation of antimicrobial potential of herbal extracts on Streptococcus mutans and Enterococcus faecalis An in vitro study / Avaliação comparativa do potencial antimicrobiano de extratos de ervas em Streptococcus mutans e Enterococcus faecalis: estudo in vitro

Though aloe vera extract, green tea extract and coriander oil are proven antimicrobial agents, very little information is available regarding its effects on oral bacteria, Streptococcus mutans, which is responsible for initiating caries and Enterococcus faecalis, responsible for failure of root canal treatment. Objective: To find the antimicrobial activity of aloe vera extract, black tea extract and coriander oil against S. mutans and E. faecalis. Materials and Methods: The agar well diffusion method was used to determine the antibacterial activity of Aloe vera extract, black tea extract and coriander oil. Different concentration of prepared plant extracts and coriander seed oil (50 & 100 µl) was incorporated into the wells and the plates containing S. mutans and E. faecalis were incubated at 37 °C for 24 h. The antibiotic (amoxicillin 30 µl) was used as positive control. Zone Of Inhibition (ZOI) was recorded in each plate. Results: For S. mutans, the maximum ZOI was created by coriander oil with a diameter of 25.00±0.58 mm at 50 µl and for E. faecalis, maximum ZOI was created by aloe vera extract 16.00±0.58 mm at 100 µl concentration which were far better than the control: amoxicillin 30 µl concentration. Conclusion: The extracts of Aloe vera, black tea and coriander oil, showed significant activity against the investigated microbial strains, Streptococcus mutans and Enterococcus faecalis which further helps in the development of new topical agents that help in reducing the numbers of these organisms present in the oral cavity. (AU)

Embora o extrato de aloe vera, extrato de chá verde e óleo de coentro sejam agentes antimicrobianos comprovados, há pouca informação disponível sobre seus efeitos nas bactérias orais, Streptococcus mutans, que é responsável por iniciar cáries e Enterococcus faecalis, responsável pela falha do tratamento de canal radicular. Objetivo: Avaliar a atividade antimicrobiana do extrato de aloe vera, extrato de chá preto e óleo de coentro contra S. mutans e E. faecalis. Materiais e Métodos: O método de difusão em agar foi usado para determinar a atividade antibacteriana do extrato de Aloe vera, extrato de chá preto e óleo de coentro. Diferentes concentrações dos extratos de plantas e óleo de semente de coentro (50 e 100 µl) foram preparados e colocados nos poços e nas placas contendo S. mutans e E. faecalis e foram incubadas a 37°C por 24 h. O antibiótico (amoxicilina 30 µl) foi utilizado como controle positivo. A zona de inibição (ZOI) foi registrada em cada placa. Resultados: Para S. mutans, a ZOI máxima foi obtida com o óleo de coentro com um diâmetro de 25,00 ± 0,58 mm a 50 µl e para E. faecalis, a ZOI máxima foi obtiada pelo extrato de aloe vera 16,00 ± 0,58 mm na concentração de 100 µl, as quais foram melhores do que o controle: concentração de 30 µl de amoxicilina. Conclusão: Os extratos de Aloe vera, chá preto e óleo de coentro apresentaram atividade significativa contra as cepas microbianas investigadas, Streptococcus mutans e Enterococcus faecalis auxiliando no desenvolvimento de novos agentes tópicos visando a redução do número desses organismos presentes no cavidade oral. (AU)

Effect of Black and Green Tea on Salivary pH: a Double Blinded Cross-Over Study / Efeito do Chá Preto e Verde no pH Salivar: um Estudo Duplo Cego Cross-Ove

Introdução: Alguns produtos à base de plantas podem afetar o pH salivar e a prevenção da cárie dentária. O consumo de chá tem efeitos inibidores sobre algumas bactérias orais. Objetivo: O objetivo deste estudo foi avaliar o efeito dos chás verde e preto sobre o pH salivar. Material e Métodos: neste estudo duplo-cego cruzado, amostras salivares de 50 estudantes saudáveis do sexo masculino da Faculdade de Odontologia de Zahedan, com idades entre 20-22 anos, foram coletadas para avaliação do pH salivar. Todos os voluntários foram solicitados a consumir chá preto comercial no primeiro dia e, em seguida, amostras de saliva foram coletadas antes de beber o chá, imediatamente após beber o chá, 5 e 10 minutos após o consumo do chá. Alternando com o consumo do chá verde, no segundo dia, as amostras de saliva foram coletadas novamente. Em seguida, o pH salivar foi estimado com um medidor de pH digital. Os dados foram analisados por meio de teste t independente e teste t de amostras pareadas. Resultados: O pH salivar médio antes e após o consumo de chá verde foi de 7,15 ± 0,05 e 7,56 ± 0,09, respectivamente, o que apresentou uma diferença notável (p <0,001). Foi de 7,14 ± 0,05 e 7,51 ± 0,10, respectivamente, para o chá preto, com diferença significativa (p <0,0001). O pH salivar médio após o consumo de chá verde foi significativamente maior do que o chá preto (p = 0,006). Conclusão: A ingestão de chá verde e preto levou a um aumento significativo no pH salivar, que foi maior após o consumo de chá verde em comparação com o chá preto. Este estudo sugere os efeitos benéficos de beber chá em fornecer um ambiente alcalino na cavidade oral (AU)

Background: Some herbal products could affect on salivary pH and prevention of dental caries. Tea consumption has inhibition effects on some oral bacteria. Objective: The aim of this study was to evaluate the effect of green and black tea on salivary pH. Material and Methods: In this double blinded cross-over trial, salivary samples of 50 healthy male students of Zahedan Faculty of Dentistry, aged 20-22 years old were collected for evaluation of salivary pH. All volunteers were asked to consume commercially black tea on the first day and then saliva samples were collected before drinking tea and immediately after drinking tea and 5 and 10 minutes after tea consumption. With replacing consumption of green tea, at the second day, saliva samples were collected again. Then the salivary pH was estimated with a digital pH-meter. Data were analyzed through independent t-test and paired samples t-test. Results: Mean salivary pH before and after green tea consumption were 7.15±0.05 and 7.56±0.09, respectively, which showed a remarkable difference (p<0.001). It was 7.14±0.05 and 7.51 ± 0.10, respectively, for black tea, with significant difference (p<0.001). Mean salivary pH after green tea consumption was significantly higher than black tea (p= 0.006). Conclusion:Both green and black tea intake led to a significant rise in salivary pH, which was higher after green tea consumption compared to black tea. This study suggests the beneficial effects of drinking tea in providing an alkaline environment in oral cavity (AU)

Inhibitory mechanism of angiotensin-converting enzyme inhibitory peptides from black tea / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The aim of this work is to discover the inhibitory mechanism of tea peptides and to analyse the affinities between the peptides and the angiotensin-converting enzyme (ACE) as well as the stability of the complexes using in vitro and in silico methods. Four peptide sequences identified from tea, namely peptides I, II, III, and IV, were used to examine ACE inhibition and kinetics. The half maximal inhibitory concentration (IC

Changes in Phenolic Content and Antioxidant Activity between Twinings English breakfast Tea Bags and Opened Tea Bags

Tea is one of the most widely consumed beverages in the world and is recognized as having numerous beneficialhealth effects due to its phenolic content. The current study aimed to evaluate and compare the phenolic andflavonoid content of two forms of Twining English Breakfast Tea: tea bags (TBs) and opened tea bags (OTBs).The antioxidant activity was also assessed using DPPH, FRAP, and CUPRAC assays. The results obtainedrevealed that the OTB infusion exhibited significantly higher phenolic and flavonoid content than the TB infusionat 5 and 10 minutes. The OTB infusion also significantly showed higher iron and cupper reducing powers thanthe TB infusion at the same time points. However, both samples demonstrated the same scavenging activity acrossall infusion times. These results suggest that the tea bags used with Twinings English Breakfast Tea may affectthe phenolic and flavonoid content released by the tea and subsequently influence the antioxidant ability of thetea as a reducing agent.

Antibacterial Activity of Black Tea Extract against S. mutans, S. aureus, L. acidophilus, Klebsiella and E. coli.

BACKGROUND Drinking tea has antioxidant, anti-inflammatory and anti-carcinogenic properties. In addition, tea is also considered beneficial for cardiovascular health and oral health. Health benefits of green tea are attributed to its polyphenol content. Catechins are the major polyphenols in green tea and in black tea the catechins are oxidized to theaflavins. Polyphenols present in tea have exhibited antimicrobial effects against a wide range of pathogenic bacteria. Studies have shown that green tea catechins are bioavailable in both plasma and urine. The aim of the present study is to evaluate the antibacterial activity of black tea extract against standard strains of S. mutans, S. aureus, L. acidophilus, Klebsiella and E. coli.METHODSBlack tea extract was prepared by boiling black tea leaves in distilled water. It was then filtered, and the filtrate was treated with chloroform and ethyl acetate. The ethyl acetate was evaporated in a rotary evaporator and a brown coloured residue was obtained. Its antibacterial activity was studied against standard strains of five common bacteria i.e.; S. mutans, L. acidophilus, S. aureus, Klebsiella spp, and E. coli and the MIC of the black tea extract was determined using serial dilution method.RESULTSBlack tea extract showed sufficient antibacterial activity against the tested bacteria. The MIC of black tea extract was lowest against Staphylococcus aureus.CONCLUSIONSTea extracts have significant antimicrobial activity at varying concentrations against different bacterial pathogens.

Influence of preparation procedures on the phenolic content, antioxidant and antidiabetic activities of green and black teas

The influence of common tea preparation procedures (temperature, infusion time, consumption time interval and tea bag/loose-leaf) and the type of water used, on the total phenolic content (TPC), the radical scavenging activity and the α-glucosidase inhibitory activity were assessed. Higher TPC and antioxidant activity were obtained when using lower mineralized waters. Tea bags also evidenced higher antioxidant activity than loose-leaf samples. Under the same conditions (90 ºC and five minutes of infusion time) green tea contains almost twice the quantity of polyphenols and the free radical scavenging ability of black tea. In the α-glucosidase assay all infusions were active (97-100 %). Furthermore, HPLC allowed to identify some of the polyphenols present in both teas and to monitor their composition change with time. After twenty-four hours, the antioxidant activity was maintained without significant changes, but a small decrease in enzyme inhibition was observed, although this activity was still very high

Black and white teas as potential agents to combine with amphotericin B and protect red blood cells from amphotericin B-mediated toxicity / Chá preto e branco de Camellia sinensis como potenciais agentes para associar com anfotericina B

Abstract Amphotericin B is a fungicidal substance that is treatment of choice for most systemic fungal infections affecting immunocompromised patients. However, severe side effects have limited the utility of this drug. The aim of this study was to evaluate the antifungal effect of the combination of amphotericin B with black tea or white tea and protective of citotoxic effect. The present study shows that white and black teas have additive effects with amphotericin B against some species Candida. In addition, the combination of white and black tea with amphotericin B may reduce the toxicity of amphotericin B to red blood cells. Our results suggest that white and black tea is a potential agent to combine with amphotericin for antifungal efficacy and to reduce the amphotericin dose to lessen side effects.

Resumo A anfotericina B é o tratamento de escolha para a maioria das infecções fúngicas sistémicas que afetam os doentes imunocomprometidos. No entanto, efeitos secundários graves têm limitado a utilidade desta droga. O objetivo deste estudo foi avaliar o efeito antifúngico da combinação de anfotericina B com chá preto ou chá branco, bem como o efeito citotóxico desta combinação sobre hemáceas. O presente estudo demonstra que o chá branco e preto de Camellia sinensis têm efeitos aditivos com anfotericina B contra algumas espécies de Candida sp. Além disso, a combinação de chá branco e preto com anfotericina B pode reduzir a toxicidade da anfotericina B em hemáceas. Nossos resultados sugerem que o chá branco e preto são agentes potenciais para associação com anfotericina B contribuindo para eficácia antifúngica, bem como redução de toxicidade.

GC-MS based metabolite profiling and angiotensin I-converting enzyme inhibitory property of black tea extracts

Abstract Angiotensin I-converting enzyme inhibitors are used as therapeutic agents for the treatment of hypertension. Regular consumption of black tea (Camellia sinensis (L.) Kuntze, Theaceae) has been reported to lower blood pressure. The aims of the present work were to compare chemical composition and angiotensin I-converting enzyme inhibitory properties of infusion and decoction of four samples of black tea. GC/MS based metabolomics approach helped in identification of fifty-one metabolites including ten organic acids, one inorganic acid, sixteen amino acids, two sugars, five sugar alcohols, fifteen phenols and flavonoids, two fatty acids from infusions and decoctions of four black tea samples. Partial least squares discriminant analysis and orthogonal partial least squares discriminant analysis models showed good classification among the two groups, diffusion and infusion, based on metabolites. Both infusion and decoction inhibited the enzyme. However, the activity differed with samples. Multivariate analysis also segregated extracts on the basis of activity. Thearubigin, theaflavin, catechin inhibited the enzyme. Epicatechin, epigallocatechin gallate, gallic acid, caffeine showed lower activity.

Black and white teas as potential agents to combine with amphotericin B and protect red blood cells from amphotericin B-mediated toxicity

Abstract Amphotericin B is a fungicidal substance that is treatment of choice for most systemic fungal infections affecting immunocompromised patients. However, severe side effects have limited the utility of this drug. The aim of this study was to evaluate the antifungal effect of the combination of amphotericin B with black tea or white tea and protective of citotoxic effect. The present study shows that white and black teas have additive effects with amphotericin B against some species Candida. In addition, the combination of white and black tea with amphotericin B may reduce the toxicity of amphotericin B to red blood cells. Our results suggest that white and black tea is a potential agent to combine with amphotericin for antifungal efficacy and to reduce the amphotericin dose to lessen side effects.

Resumo A anfotericina B é o tratamento de escolha para a maioria das infecções fúngicas sistémicas que afetam os doentes imunocomprometidos. No entanto, efeitos secundários graves têm limitado a utilidade desta droga. O objetivo deste estudo foi avaliar o efeito antifúngico da combinação de anfotericina B com chá preto ou chá branco, bem como o efeito citotóxico desta combinação sobre hemáceas. O presente estudo demonstra que o chá branco e preto de Camellia sinensis têm efeitos aditivos com anfotericina B contra algumas espécies de Candida sp. Além disso, a combinação de chá branco e preto com anfotericina B pode reduzir a toxicidade da anfotericina B em hemáceas. Nossos resultados sugerem que o chá branco e preto são agentes potenciais para associação com anfotericina B contribuindo para eficácia antifúngica, bem como redução de toxicidade.

Determination of mycotoxins in pu-erh tea, black tea, and green tea samples / 中国中药杂志

To establish a robust method for the determination of mycotoxins in tea samples, and to provide means for the quality and safety control of tea products. Samples of 20 tea products acquired from international market were extracted by organic solvents (acetonitrile containing 0.1% formic acid) or hot water, respectively. The extracts were analyzed by UPLC-MS/MS.A good linear regression was achieved in a range of 39.1 to 5 000 ng•L⁻¹ for aflatoxin B1 (AFB1) and aflatoxin G1 (AFG1), 117 to 15 000 ng•L⁻¹ for aflatoxin B2 (AFB2) and aflatoxin G2 (AFG2), 2.44 to 313 ng•L⁻¹ for fumonisin B1 (FB1), fumonisinB2 (FB2) and fumonisin B3 (FB3), and 3 125 to 5 000 ng•L⁻¹ for deoxynivalenol, with recovery rates between 85.7% and 99.6%. The coefficient of the linear equation for all standards was greater than 0.999 0, and the RSD value was less than 10%. Mycotoxins were detected in several tea samples using the two extraction methods but with different outcomes. The levels of mycotoxins detected ranging from 0.15 to 7.31 μg•kg⁻¹ were well below the State or US FDA regulation limits of mycotoxins in food products. Both methods are simple, accurate, and sensitive, and thus, suitable for the quantitative determination of mycotoxins in different food products. The method with the 80 ℃ hot-water extraction is more appropriate to determine the trace amounts of mycotoxins in tea leaves that are likely to be present in brewed tea liquor, while organic solvent method is more suitable for the detection of mycotoxins in ingestible foods.

Antioxidant potential of yerba mate (Ilex paraguariensis St. Hil.) extracts in Saccharomyces cerevisae deficient in oxidant defense genes / Potencial antioxidante de extratos de erva-mate (Ilex paraguariensis St. Hil.) em Saccharomyces cerevisiae deficientes para genes de defesa oxidante

Abstract Yerba-mate (Ilex paraguariensis St. Hil) is mainly consumed as “chimarrão”, a hot drink highly appreciated in Brazil, Argentina, Paraguay and Uruguay. This study evaluated the antioxidant potential of aqueous extracts of I. paraguariensis precipitated with ethanol. The leaves were processed as for tea product (TM) and oxidized (OX). The antioxidant potential was evaluated in cells of Saccharomyces cerevisiae deficient in antioxidant defense genes. Three strains evaluated were: a wild (EG) and two mutants (ctt1Δ e ctt1Δsod1Δ). These strains were pre-treated with the yerba-mate extracts (TM e OX) and submitted to oxidative stress induced by hydrogen peroxide. None of the extracts produced loss of cell viability. The extracts exerted antioxidant activity, protecting the strains (except sod1∆ctt1∆). The TM extract was more effective than OX. I. paraguariensis extracts showed a potential to be explored in the development of new products.

Resumo A erva-mate (Ilex paraguariensis St. Hil) é consumida principalmente como “chimarrão”, uma bebida quente muito apreciada no Brasil, Argentina, Paraguai e Uruguai. Este estudo avaliou o potencial antioxidante de extratos aquosos de I. paraguariensis precipitado com etanol. Folhas de erva-mate foram processados de maneira semelhante ao processamento do chá-preto (OX) e na forma de mate (TM). O potencial antioxidante foi avaliado sobre células de Saccharomyces cerevisiae deficientes para genes de defesa antioxidante. Três linhagens celulares foram estudadas: uma selvagem (EG) e duas mutantes (ctt1Δ e ctt1Δsod1Δ). As linhagens foram pré-tratadas com os extratos de erva-mate (TM e OX) e submetidos ao estresse oxidativo induzido por peróxido de hidrogênio. Nenhum dos extratos produziu perda de viabilidade celular. Os extratos exerceram atividade antioxidante, protegendo as linhagens (exceto a sod1Δctt1Δ). O extrato TM foi mais eficaz em relação ao OX. Extratos de I. paraguariensis apresentaram potencial para ser explorado no desenvolvimento de novas formulações.

Study on processing technology for fermentation of Chinese gall leaven based on components analysis and antibacterial test / 中草药

Objective: To optimize the processing technology for Chinese gall leaven by orthogonal test. Methods: The L9(34) orthogonal test was used taking the main contents of gallic acid, ellagic acid, and in vitro antibacterial activity as indexes of evaluation. The affecting factors contains factor A, the species of zymocyte, such as Rhizopus koji, Angel yeast, and Aspergillus niger, factor B, the species of tea, such as green tea, black tea, and puer tea, factor C, the material ratios of quantity of raw material, yeast, and tea, such as 25:7.5:2.5, 25:6.25:1.1, and 25:2.5:1.9. Multi-index comprehensive weighted mark method was used in the data analysis. Results: The best processing technology was set at A1B2C1, that strain selection was R. koji, with green tea, and the material ratio was 25:7.5:2.5. Conclusion: The studies show that this processing technology is stable and feasible. The research provides the reference data for processing Chinese gall leaven.

Determinação da atividade antioxidante In vitro das bebidas de café e chás verde e preto / Determination of In vitro antioxidant activity of the beverages of coffee, green tea and black tea

Conforme demonstrado em diversos estudos, determinadas plantas e alimentos, apresentam propriedades protetoras à saúde devido à presença de antioxidantes. Sendo assim, o presente trabalho teve como objetivo comparar o efeito antioxidante in vitro de bebidas comercializadas de café, chá verde e chá preto, utilizando a combinação de diferentes metodologias. As bebidas foram preparadas no momento de uso, de acordo com as especificações do fabricante. Foram realizados testes para determinar o teor de polifenóis nas bebidas, e avaliar o seu poder redutor, bem como sua capacidade de quelar íons de metais de transição (Fe2+) sequestrar radicais livres, e inibir a peroxidação de lipídeos. O café apresentou maior teor de compostos fenólicos, seguido do chá verde e do chá preto (p<0,05). A análise dos resultados não revelou diferenças entre as três bebidas analisadas em relação ao poder redutor e à capacidade de inibir a peroxidação de lipídeos (p>0,05). A bebida de café apresentou uma maior atividade quelante do que o chá preto enquanto que o chá preto e o café apresentaram maior capacidade sequestrante de radicais DPPH em comparação com o chá verde. Os dados obtidos permitem sugerir que a bebida de café, provavelmente por ter maior concentração de polifenóis, pode ser considerada a melhor no que diz respeito à atividade antioxidante. Assim, a bebida de café, além de ser uma das bebidas mais populares do mundo por seu aroma e sabor, poderia também contribuir para a prevenção de danos oxidativos de maneira mais eficiente que os chás analisados neste estudo.(AU)

Numerous studies have demonstrated that certain plants and foods exhibit health protective properties due to the presence of antioxidants. In this sense, the present study aimed to compare the in vitro antioxidant effect of the commercialized beverages of coffee, green tea and black tea by using a combination of different methodologies. The beverages were prepared at the time of use, according to the manufacturer?s specifications. We determined the polyphenol content in the beverages and examined their reducing power, as well as their ability to chelate transition metal ions (Fe2+), scavenge free radicals, and inhibit lipid peroxidation. The beverage of coffee contained the highest amounts of phenolic compounds, being followed by green tea and black tea (p<0.05). The results revealed no differences among the three beverages regarding their reducing power and lipid peroxidation-inhibiting activity (p>0.05). The beverage of coffee displayed higher metal chelating ability than black tea. The beverages of black tea and coffee scavenged DPPH radical more effectively than green tea. The data obtained suggest that the beverage of coffee can be considered the best one regarding the antioxidant activity, probably due to its highest content of polyphenols. Thus, the beverage of coffee, one of the most popular beverages in the world for its aroma and flavor, could also contribute to prevent the oxidative damage more efficiently than the teas analyzed in this study.(AU)

In vitro anti-hyaluronidase activity of Sri Lankan low grown orthodox orange pekoe grade black tea (Camellia sinensis L.)

Objective: To access the anti-hyaluronidase activity of Sri Lankan low grown orthodox orange pekoe (OP) grade black tea with a view to develop an anti-aging skin formulation. Methods: Five concentrations (0.125, 0.250, 0.500, 1.000 and 2.000 mg/mL) of black tea brew (BTB) were made using a freeze dried sample of Sri Lankan low grown orthodox OP grade black tea which was prepared according to international organization for standardization specification. Epigallocatechin gallate (EGCG) was used as the reference agent (concentrations tested: 0.012, 0.025, 0.050, 0.100 and 0.200 mg/mL). Anti-hyaluronidase activity of BTB and EGCG in vitro were ascertained spectrometrically using hyaluronic acid (from rooster comb) and bovine testicular hyaluronidase. Results: The results revealed that BTB had moderate [IC

In vitro anti-hyaluronidase activity of Sri Lankan low grown orthodox orange pekoe grade black tea (Camellia sinensis L.)

To access the anti-hyaluronidase activity of Sri Lankan low grown orthodox orange pekoe (OP) grade black tea with a view to develop an anti-aging skin formulation. Methods: Five concentrations (0.125, 0.250, 0.500, 1.000 and 2.000 mg/mL) of black tea brew (BTB) were made using a freeze dried sample of Sri Lankan low grown orthodox OP grade black tea which was prepared according to international organization for standardization specification. Epigallocatechin gallate (EGCG) was used as the reference agent (concentrations tested: 0.012, 0.025, 0.050, 0.100 and 0.200 mg/mL). Anti-hyaluronidase activity of BTB and EGCG in vitro were ascertained spectrometrically using hyaluronic acid (from rooster comb) and bovine testicular hyaluronidase. Results: The results revealed that BTB had moderate [IC50=(1.09±0.12) mg/mL] and dose dependent (r2=0.94) anti-hyaluronidase activity. EGCG also exhibited dose dependent (r2=0.93, P<0.05) anti-hyaluronidase activity which was superior [IC50=(0.09±0.00) mg/mL] to BTB. Conclusions: Sri Lankan low grown orthodox OP grade black tea has promising anti-hyaluronidase activity in vitro and has the potential to be used as an anti-aging cosmaceutical. In addition, it may prove useful as a beverage in the management of allergy, some joint diseases and envenomation.

Black Tea Inhibits Small Intestinal α-Glucosidase Activity in <i>db/db</i> Mouse / 日本補完代替医療学会誌

The inhibitory effects of the freeze-dried powder of the aqueous extract of black tea leaf (JAT) on α-glucosidase activity were investigated. We initially examined the effects of JAT addition on yeast α-glucosidase activity. JAT significantly and dose-dependently inhibited α-glucosidase activity and more strongly inhibited the activity than acarbose, the positive control. Then, we examined the effects of oral administration of JAT on sucrose tolerance in type 2 diabetes mellitus model <i>db/db</i> mice. Both JAT and acarbose administered groups showed a dose-dependent decrease in plasma glucose levels after the sucrose loading compared with the control group. Notable was that the plasma glucose levels of the 500 mg/kg JAT administered group exhibited a significant decrease 30 min or longer after the sucrose loading. On the other hand, no significant difference in plasma insulin levels was seen between the JAT administered group and the control group. We also measured small intestinal sucrase activity in <i>db/db</i> mouse at 30 min after JAT oral administration. Compared to control mice, small intestinal sucrase activity was significantly decreased in the 500 mg/kg JAT administered mice. These findings indicate that JAT may be a useful natural material for the prevention and therapy of type 2 diabetes mellitus.<br>

Effect of different types of tea on Streptococcus mutans: An in vitro study.

Context: If tea can be shown to have an inhibitory effect on the growth of Streptococcus mutans there can be a basis for using it as an agent for reducing caries. Aims: The aim of the study was to determine the effect of aqueous and organic extracts of three types of tea (green, oolong, and black tea) on the growth of S. mutans. Settings and Design: In vitro study. Material and Methods: Qualitative and quantitative phytochemical analysis of the three types of tea was done. Organic extracts of methanol and ethanol and aqueous extracts (50% and 100%) of tea were prepared. Fifty microliters of these extracts were inoculated into wells prepared on Mueller-Hinton agar plates that had been previously smeared with S. mutans. The agar plates were incubated at 37΀C for 24 hours. A similar procedure was followed using 0.2% chlorhexidine, which served as the positive control. Statistical Analysis Used: Analysis of variance (ANOVA), post hoc Tukey test, Student's 't ' test (two-tailed, dependent), and Student's 't' test (two-tailed, independent) were used for analysis of the data. Results: All the phytochemicals were found to be higher in oolong tea. Both aqueous and organic extracts of oolong tea showed greatest zones of inhibition, followed by green tea and black tea. Aqueous extracts of oolong and green tea showed greater zone of inhibition than chlorhexidine. All the three types of tea inhibited growth of S. mutans. The greatest inhibition was observed with aqueous extract of oolong tea. Conclusions: Oolong tea extracts (aqueous and organic) showed a greater inhibitory effect on the growth of S. mutans than the other tea extracts.