Black Tea Extract Research Articles

The effect of black and green tea extracts on some bacteria-infected burns skin in rats

Herbal teas are the most common natural alternatives for the treatment of infectious diseases due to increasing antibiotic resistance, and are increasingly gaining more popularity and are known for their activity of antibacterial to many pathogenic micro-organisms. This research was necessitated by the need to counter the rapid emergence of drug-resistant human pathogens, which is becoming a regular phenomenon in the world making life-threatening illnesses easily curable infections. The study was done to determine the antimicrobial activities by agar diffusion inhibition assay of black and green tea Extract (cold and hot) against Pseudomonas aeruginosa and Staphylococcus aureus antibiotic resistance after injuring the skin of rats for burning, also to screen the effect of both types of tea on rat skin healing. Minimum inhibitory concentration was performed by broth micro-dilution assays, and Antibiotic Sensitivity was done for both types of bacteria. Our findings are in accordance that hot watery green and black tea extracts are more effective against both bacterial types than cold once based on an assessment of inhibition zones, green tea extract could be used for wound healing and burned skin of rats when treated with green and black tea showed reductions in the number of inflammatory cells and also arranged collagen bands. We concluded that green tea has a greater activity which is indicated by a higher anti-inflammatory effect compared to black tea.

Emulsifying properties and antioxidant activity of soy protein isolate conjugated with tea polyphenol extracts.

Functional properties of proteins, such as emulsification, foam formation and antioxidant activity, can be improved by conjugating the proteins with phenolic substances. We reported here changes in the structural, physicochemical and functional properties of Soy Protein Isolate (SPI) after conjugation with phenolic substances in the green tea and black tea extracts. Conjugation of SPI with tea extracts were conducted using alkaline treatment (pH 9.0) followed by air exposure. The results showed that conjugation of SPI increased the protein molecular size and decreased the protein hydrophobicity. The hydrophobic decreasing effect by the treatment was larger with the black tea extract than by green tea extract. SPI-tea polyphenol conjugates significantly (p < 0.05) increased the emulsifying ability of SPI up to 43% and the emulsifying stability of SPI up to 59%. SPI-tea polyphenol conjugates which was prepared using 0.75% (w/w SPI) green tea polyphenol extract showed the best emulsifying properties with strong repulsion forces between the droplets, smaller emulsion droplet size and lower polydispersity index of droplets size distribution. Although the conjugation product is still inferior to egg lecithin in emulsion stability, antioxidant activity of SPI was significantly (p < 0.05) improved in a concentration dependant manner. SPI-black tea polyphenol conjugates showed greater antioxidant activity than SPI-green tea polyphenol conjugate. The present study shows the feasibility and benefits of the use of SPI-tea polyphenol conjugates as a food emulsifier.

Synthesis and Characterization of Reduced graphene oxide from coal using black tea extract

Synthesis and Characterization of Reduced graphene oxide from coal using black tea extract

Green synthesis and characterization of Camellia sinensis mediated silver nanoparticles for antibacterial ceramic applications

This study focuses on the use of green synthesized silver nanoparticles (Ag-NPs) with the aid of Camellia sinensis (black tea) extract to provide antibacterial activity on ceramic structure. The synthesized Ag nanoparticles were added to the glaze used in the ceramic structures and mixed homogeneously. The homogeneous mixture was characterized by transmission electron microscopy (TEM), X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–Vis spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR) techniques. The SPR band of the synthesized biogenic Ag NPs was observed as 422 nm during the reaction at room temperature. TEM analysis revealed that Ag NPs were spherical and a particle size between 10 and 20 nm. Furthermore, the antibacterial properties of the homogeneous mixture (Ag NPs and glaze) were tested against Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Methicillin-resistant Staphylococcus aureus (MRSA) bacteria. Biogenic Ag NPs at a concentration of 100 μg/ml were observed to have 90%, 75%, 75%, 80% lethal effects against S. aureus, MRSA, B. Subtilis, and E. Coli bacteria, respectively. The antibacterial results of Ag NPs obtained with the help of Camellia sinensis show that they may have potential application and development in the field of ceramics. In addition, the antibacterial activity of commercially available antibiotics and the prepared Ag NPs were analyzed in ceramic glazes.

Tea extracts differentially inhibit Streptococcus mutans and Streptococcus sobrinus biofilm colonization depending on the steeping temperature

This study aimed to evaluate the effects of tea extracts on oral biofilm colonization depending on steeping temperature. S. mutans and S. sobrinus were cultured and treated with green or black tea extracts prepared under different steeping conditions. Biofilm formation, glucosyltransferase (GTF) levels, bacterial growth, and acidogenicity were evaluated. Biofilms were also assessed by gas chromatography-mass spectrometry and confocal laser scanning microscopy. All extracts with hot steeping showed higher inhibitory effects on biofilm formation and cell viability and lower GTF levels compared with those with cold steeping (p < 0.05). Hot steeping significantly reduced bacterial growth (p < 0.05) and maintained the pH. Catechins were only identified from hot steeping extracts. Within the limits of this study, extracts with cold steeping showed lower inhibitory effects on oral biofilms. The different effects between steeping extracts may be attributed to the difference in catechins released from tea extracts under the different steep conditions.

In vivo effects of black tea on the male rat reproductive system and functions of the kidney and liver.

This study focused on the effects of black tea on the male reproductive system as well as the kidney and liver functions. Male Wistar rats were given aqueous extract of black tea (2% and 5%) for 52days as the only means of drinking fluid, while control rats received tap water. Black tea enhanced sperm vitality (44%-49%), total sperm motility (10%-12%) and acrosome reaction (2%-9%) (p<.05). Body weight gain, testis, epididymis, seminal vesicles, prostate, liver weight, testosterone level, sperm concentration, ferric reducing antioxidant power (FRAP) and antioxidant levels in the testes, liver and kidney remained unchanged (p > .05). Black tea (5%) increased kidney weight (p < .05). Testis and epididymis showed normal histological appearance. However, black tea significantly reduced the diameter (9%-10%) and epithelial height (9%-10%) of the seminiferous tubule, but increased the epithelial height of the cauda epididymis (8%-24%) (p<.05). A significant reduction in serum levels of alanine aminotransaminase (ALT) (38%) and aspartate aminotransaminase (AST) (23%-34%) was observed (p<.05); creatinine level, on the other hand, increased (8%-72%) (p<.05). Black tea improved several sperm parameters, but may cause subtle changes in certain reproductive organs and the kidney functions.

Black Tea Extract on the Preservation of Cantonese Sausage

Black Tea Extract (BTE) is a natural pigment with strong antioxidant activity. Its effect on the preservation of Cantonese sausage was investigated based on polyphenol components analysis in this study. The content of tea polyphenols in BTE was 26.61% by using spectrophotometry, the tea catechin in BTE was analyzed by HPLC, which included gallic acid (0.27%), caffeine (5.75%) and 8 catechins (0.87% Catechin, 1.66% epicatechin, 0.34% catechin gallate, 2.54% epicatechin gallate, 1.88% gallocatechin, 5.31% epigallocatechin, 2.69% gallocatechin gallate, 10.23% epigallocatechin gallate). The tea sausages of five treatments with the addition of 0.05, 0.10, 0.15, 0.20 and 0.25% BTE were designed, compared to the control and the sausage with the addition of 0.02% sodium Nitrite (NIT) and the addition of 0.01% NIT and 0.01% BTE. The acid value, peroxide value and sensory indices were analyzed and the shelf-life of the sausage was predicted by peroxide value. The sausage with 0.15% BTE had significant improved the product quality by reducing the acid value and lipid oxidation value. The nitrite and BTE had synergistic inhibition of acid value increase. The BTE had the positive effect on the color of the freshly prepared sausage, but this effect was not obvious during the storage. The sensory value of the control sausage was decreased by 42.12% when stored for 30 days, while sausages added with BTE was decreased by only about 13.34%. BTE showed more potential in Cantonese sausage preservation and the sausage with more than 0.15% addition of BTE had twice shelf-life (40℃) more than that of 0.02% sodium nitrite sausage and five times more than that of control group. Adding BTE in sausage could be a good potential for reducing the usage of nitrite in meat products.

Corrigendum: Effect of Black Tea Extract and Thearubigins on Osteoporosis in Rats and Osteoclast Formation in vitro

[This corrects the article DOI: 10.3389/fphys.2018.01225.].

Effects and molecular mechanisms of Ninghong black tea extract in nonalcoholic fatty liver disease of rats.

The aim of this study is to observe the effects of Ninghong black tea extract on fat deposition and high-fat diet-induced nonalcoholic fatty liver disease (NAFLD) and to explore the potential mechanisms of these effect. Under 2% Ninghong black tea extract diet feeding in rat model, the results showed that Ninghong black tea extract decreased the body fat ratio and the number of lipid droplets in the liver and significantly alleviated NAFLD in the rat model. The real-time fluorescence quantitative polymerase chain reaction results showed that Ninghong black tea extract significantly upregulated the expression of peroxisome proliferator-activated receptor α (PPARα), which is important in fatty acid β-oxidation, and microsomal triglyceride transfer protein (MTP), which plays an important role in the synthesis of very low density lipoprotein (VLDL). By promoting the expression of PPARα and MTP in liver tissue and thereby promoting fatty acid β-oxidation and VLDL synthesis, Ninghong black tea extract relieves high-fat diet-induced NAFLD.

Effect of Black Tea (camellia sinensis) on Serum Adiponectin Level in Atherogenic Diet Rats

The aim of this study is to investigate the effect of black tea administration on serum adiponectin level in male Wistar fed with atherogenic diet (AD). This study was designed as a true experimental design that assigns 20 rats, and divides them into four groups as follows: P1 (AD 3 months); P2, P3, and P4 (3 months AD + black tea extract administration at dosage 0.015gr/day, 0.03gr/day, 0.045gr/day, respectively). Serum adiponectin level was measured using ELISA method. This study demonstrated that there is an elevation trend of adiponectin level as the dose elevated. However, serum adiponectin level in AD-only group (380.6ng/mL) was not significantly different with treatment group (386.93ng/mL, 404.27ng/mL, and 416.6ng/mL in P2, P3, and P4, respectively) (ANOVA, p = 0.352). Furthermore, there was no significant association between the dosage of black tea and adiponectin levels (Pearson correlation test, p = 0.073, r = 0.373). We concluded that black tea extract increased serum adiponectin level insignificantly in atherogenic diet rats.

Evaluation on Gallic Acid, EGCG Contents and Antiradical Activity of Green Tea and Black Tea Extracts

Amac: Cay, dunyada cok iyi bilinen ve tuketilen bir icecek olup antioksidan aktivitesine bagli koruyucu etkileri bilinen onemli bir fitobesindir. Bu calismanin amaci, Kuzey Anadolu kaynakli Camellia sinensis bitkisinden elde edilen yesil cay ve siyah caydan hareketle elde edilen ekstrelerdeki gallik asit ve epigallokatesin gallat miktari ile ekstrelerin antiradikal aktivitesinin tespit edilmesidir. Gerec ve Yontem: Yesil cay ve siyah cayin etanol, metanol ve sulu ekstrelerindeki gallik asit ve epigallokatesin gallat miktar tayini YPSK yontemi ile tespit edilmis ve ekstrelerin antiradikal aktivite tayini icin DPPH ve ABTS yontemleri kullanilmistir. Sonuc ve Tartisma: Toplam 6 ekstredeki gallik asit icerigi 0.052-1.341 mg/100 ml araliginda bulunmus ve EGCG (epigallokatesin gallat) icin bu deger araligi 0-19.54 mg/100ml olarak tespit edilmistir. Hem DPPH hem de ABTS radikali uzerinde en iyi etkiyi yesil cayin sulu ekstresinin sagladigi belirlenmistir. Yesil cayin, koruyucu saglikta degerlendirilebilecek iyi bir aday oldugu ancak fitobesin ve farmasotik kalitede urunun formulasyon calismalarinda, bitkinin hasat yontemi, bitkiden hareketle cay uretim prosesi, optimum karistirma zamani, kullanilan cozucu ve yapraklarin parcalanma derecesinin kayit altina alinmasi gerekmektedir.

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.

English

English

Black Tea (Camellia sinensis) Extract Induced Changes on Placenta can Alter Fetal and Neonatal Bone Health in Experimental Animal Model

Tea (Camellia sinensis) being the most consumed beverage worldwide. The safety evaluation of tea needs to be monitored during pregnancy, prenatal and postnatal developmental period beside its beneficial roles toward health and disease. Retardation of growth of fetus and neonates are common in preeclampsia. Present study was to evaluate the role of Black Tea extract (BTE) on placental and apoptotic markers in pregnant Wister albino rats and to correlate it the growth of fetus and pups. Among three experimental groups, Group 1 was pregnant female rats treated with saline, were the control group. Group 2 and Group 3 were pregnant female rats treated with 50 mg and 100 mg BTE/kg/day, p.o. respectively throughout prenatal and postnatal periods. Expressions of BMP-7, MMP-2 and VEGFR2 in placenta were examined by flow cytometry; Bax, Bcl-2 and caspase-3 expressions in uteri and placenta were observed by IHC. Bone health of fetus and pup were checked by histology, bone-cartilage double staining and estimation of bone mineral density by ICP-MS. Experimental data were subjected to the ANOVA; expressed as mean ± standard deviation with significance (P &lt; 0.05) between the controls and the treated groups (n = 6). BTE increased the level of MMP-2, Bax and caspase-3; decreased the level of BMP-7 in placenta. In fetus and pups, BTE significantly decreased the concentration of Ca2+, P, Mg2+ and Zn2+ in bone and decreased the rate of ossification were observed. This study confirmed BTE induced preeclampsia retarded the fetal and neonatal bone health in experimental animal model

Antibacterial activity of watery and ethanolic extracts of Black Tea and peppermint (In vitrostudy)

Background:The most important medical challenge is the emergence of bacterial resistant to traditional antibiotics. So the need for new pharmaceutical compound derived from daily intake plant material. Mint and black tea used extensively in Arabic area as hot or cold drink &#x0D; Objective: investigate the bacterial activity of mint and black tea aqueous extract against many bacterial genera.&#x0D; Material and methods: from the local market of Baghdad Province, Iraq, dry black tea was obtained; while, peppermint (Mentha piperita L) was harvested from Iraqi plants during April 2020. Active ingredients extracted using either ethanol or water and their antibacterial activity evaluated against Staphylococcus aureus, S.epidermidis, Citrobacter sp and Klebsiella sp using well diffusion agar under invitro laboratory condition.&#x0D; Results: Dried powder of each extract appeared with different color range from brown to black. Results recognized that S. aureus was susceptible to watery and ethanolic extract of both black tea and peppermint extracts. While, S. epidermidis showed resist to both plant extract and solvents used in extraction except minor inhibition with ethanolic extract of tea at 0.3% dose dose. Citrobacter spp gave susceptibility to watery extract of black tea as well as, watery and ethanolic of mint extract. Otherwise, Klebsiella spp. Growth inhibited by watery extract of black tea while, no bioactivity existed upon mint extract treatment. &#x0D; Conclusion: Dose dependent manner existed for watery and ethanolic extracts for both plant material in their antibacterial activity.&#x0D;

The protective role of black tea extract against indomethacin-induced toxicity in the prostate gland of rats

Introduction: Indomethacin (NSAID) is an endocrine-disrupting chemical (EDC) that has been demonstrated to induce alterations in reproductive organs while Black Tea Extract (BTE), an antioxidant, is capable of protecting against EDC-induced alterations. Aims & Objectives: The current study was designed to investigate the role of black tea extract on biochemical, hormonal, and histological changes in the prostate of male Wister rats treated with indomethacin drugs. Materials and Methods: Adult rats were divided into four groups (n = 6/group); Group I (control); Group II (indomethacin, 5 mg/kg b.wt.; i.p.); Group III (BTE, 2.5 g tea leaf/dL of water, i.e., 2.5% of aqueous BTE, orally) and Group IV (indomethacin + BTE) for 21 successive days. Sperm Count, Motility, Prostate-Specific Antigen (PSA), Testosterone levels, total protein, GSH, CAT, and MDA levels and the histopathological aspects of the prostate gland were studied. Statistical Analysis: Statistical comparisons were performed using the one-way ANOVA, followed by post-hoc t-test. Results: Indomethacin treated rats “Group” II exhibited a significant (P≤0.05) declining in the sperm count, motility PSA and testosterone concentration, total protein, GSH concentration, and CAT activity. A high concentration of MDA levels in the serum indicated the appearance of oxidative stress status in the Wister rats. The indomethacin had a significant impact on the weight, and histopathology of glandular “acini” and excretory “ducts” revealed hyperplasia, intra-luminal budding of epithelia as well as tubular atrophy. Conclusion: Administration of black tea extract abrogated the toxic effect induced by indomethacin on the prostate gland.

Voltammetric Determination of Free and Total Manganese in Tea Infusions

Tea infusions are a source of mineral nutrients, including manganese. Although it is classified as an essential element, the excess of manganese is toxic for humans and its toxicity depends on its bioavailability. In this context, we propose a simple procedure to determine free and total manganese in black tea infusions by square-wave voltammetry (SWV). Free manganese was directly quantified in the samples after simple sample dilution in 0.1 mol L−1 acetic acid/acetate buffer (pH = 4.5) while total manganese determination was carried out after sample digestion with oxidant mixture (HNO3 + H2O2). For comparison, cloud point extraction was performed to remove organic-bound manganese and the content of free metal (not extracted) measured by flame atomic absorption spectrometry (F AAS) agrees with the values obtained by the proposed SWV procedure. The limit of detection and quantification were estimated for manganese determination as 0.06 and 0.20 µg L−1, respectively, with a linear range observed between 20 and 250 µg L−1. The coefficient of variation was 9.7% (50 µg L−1, n = 10). The procedure was applied to determination of free and total manganese in black tea bags and the results were compared with literature procedures employing F AAS.

Phytochemical analysis and assessment of Antioxidant properties of black tea extract obtained from Camellia sinensis

The objective of this study was to conduct phytochemical characterization and antioxidant evaluation of black tea extract (BTE) obtained from Camelia sinensis. Fermented extract from leaves were obtained for phytochemical screening and evaluation of In-vitro antioxidant potential. Phytochemical data revealed the presence of several metabolites, notably from the flavonoid and phenolic class. In the antioxidant activity using the DPPH method, nitric oxide method, superoxide method, hydroxyl radical method and reductive method the enriched extract presented significant IC50 values when compared with ascorbic acid as a standard. These results contribute to the continuity of studies on the chemical and biological composition of the species.

Black tea classification based on its electrophoretic profile

The problem of food authenticity control is relevant from both a theoretical and a practical point of view. Various approaches are applied to product identification, for example, the search for marker substances and pattern recognition methods. The latter considers profiles of various nature as a single characteristic feature of the product, which allows one to obtain a classification model of objects. Another way to compare profiles is to build and visually compare the petal diagrams. This paper is aimed at studying the electrophoretic profile of black tea and identifying characteristics which make it possible to classify tea according to the geographical origin, without considering the technology of its manufacture. The methodology for the determination of caffeine, catechin, epigallocatechin gallate, epicatechin and gallic acid in tea extracts was tested by micellar electrokinetic chromatography method. The range of determination linearity was established and amounted to 0.5-200 μg / ml for all the components under study, the error in the analytes determination did not exceed 15%, the standard deviation of the peak area on the electrophoregram was less than 10%. We have examined the electrophoretic profiles of black tea extracts of various origins and observed nine characteristic peaks that were satisfactorily reproduced, were legal, and were present in all the samples. An array of data was generated based on the characteristic peaks areas on the electrophoregrams recorded for extracts of Assamese, Ceylon and “original” Krasnodar tea. To level the influence of values spread of the characteristic peaks areas, they were related to each other. The application to the matrix of data, which included the ratio of the characteristic peak areas, of the variance analysis with subsequent processing of its results using the principal component method, made it possible to establish the ratios most influencing the sample reference to a certain tea group. Based on the selected area ratios, a graphic model for classifying black tea by origin was constructed. It was verified, and satisfactory results were obtained. “Visual images”, built on the medians of the characteristic peaks areas ratio, clearly show the differences in the tea sample groups of Ceylon, Assamese and Krasnodar origin. Key words : polyphenols, black tea, micellar electrokinetic chromatography method, electrophoretic profiles, principal component method DOI: http://dx.doi.org/10.15826/analitika.2020.24.3.001 K.S. Gushchaeva, T.G. Tsiupko, O.B. Voronova Kuban State University, Stavropolskaia ul.,149, Krasnodar, 350040, Russian Federation

Neuroprotective Effects of Tea Against Cadmium Toxicity

Background: Cadmium (Cd) is a common pollutant and potential neuro-toxicant to humans. The main treatment for heavy metal toxicity is chelation therapy which is however replete with grave side effects. This study was designed to determine the neuroprotective effects of extracts of the tea beverage on experimentally induced cadmium toxicity in the brain of rats. Cadmiumas CdCl2 was administered subcutaneously while tea was given orally.Methods: Healthy Wister rats were used to study the effects of co-administration of Cd and tea extracts on the brain. Cadmium was injected subcutaneously while tea was administered orally to the rats. Brain tissue from euthanized rats was assayed for Zinc Fingers and Homeoboxes Protein 1 (ZHX1), reduced glutathione (GSH), and lipid peroxidation markers Thiobarbituric Acid Reactive Substances (TBARS). Neurohistochemical and histopathological studies were also carried out on the brain tissues of the rats.Results: Cadmium significantly induced neuronal damage exhibited by a significant (p &lt; 0.05) decrease in ZHX1 in the brain tissue, significant (p &lt;0.05) increase in TBARS, as well as significant (p &lt; 0.05) increase in GSH implying an impaired antioxidant defense system. Co-administration of Cd with black or green tea extracts resulted in a significant decrease in lipid peroxidation as well as maintenance of GSH and ZHX1. The neurohistochemical and histopathological studies in the brain of the rats indicated that the tea extracts significantly reduced CdCl2 toxicity and preserved the normal histological architecture of the brain tissues.Conclusion: This paper reports for the first time the efficacy of tea extracts in protecting rats from cadmium induced toxicity and disturbances of antioxidant defense system in the brain.Key words: Tea; flavonoids; Cadmium; neurotoxicity; Chelating agents.