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  1. Okekpa SI, S. M. N. Mydin RB, Ganeson S, Gopalan S, Musa MY
    Asian Pac J Cancer Prev, 2020 08 01;21(8):2183-2187.
    PMID: 32856842 DOI: 10.31557/APJCP.2020.21.8.2183
    Heated debates have been on-going about tea consumption and the incidence of cancer, especially in head and
    neck cancer types. This study aimed to review the association between tea consumption habits and nasopharyngeal
    cancer (NPC). Methods: This review was carried out in accordance with the PRISMA-P protocol. Literature search
    for journal articles that published studies on the relationship between tea consumption and NPC was performed via
    databases, such as Elsevier, PubMed, Science Direct, Springer Link, Google, and Google Scholar, for 10 years from
    2008 to 2018. Relevant studies were obtained by applying the pre-determined keywords, such as nasopharyngeal cancer,
    tea consumption and NPC, risk factors of NPC and benefits of tea consumption. Results: A total of 126 articles was
    retrieved. These articles were subjected to eligibility assessment. Six articles remained after applying the inclusion
    criteria. Results suggest that habitual tea consumption reduces NPC. Tea consumption significantly reduces NPC with
    all the studies having a p-value ≤0.05. Meta-analysis showed statistical association between tea consumption and NPC
    risk with OR=0.865 at 95% CI (0.806-0.929). Conclusion: This study suggests that habitual tea consumption could
    be associated with prevention of NPC development. Additional studies are needed to further understand the molecular
    role of bioactive compound and potential health benefit of tea consumption in NPC prevention.
    Matched MeSH terms: Tea/chemistry*
  2. Panneerselvam P, Morad N, Tan KA
    J Hazard Mater, 2011 Feb 15;186(1):160-8.
    PMID: 21146294 DOI: 10.1016/j.jhazmat.2010.10.102
    The removal of Ni(II) from aqueous solution by magnetic nanoparticles prepared and impregnated onto tea waste (Fe(3)O(4)-TW) from agriculture biomass was investigated. Magnetic nanoparticles (Fe(3)O(4)) were prepared by chemical precipitation of a Fe(2+) and Fe(3+) salts from aqueous solution by ammonia solution. These magnetic nanoparticles of the adsorbent Fe(3)O(4) were characterized by surface area (BET), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infrared Spectroscopy (FT-IR). The effects of various parameters, such as contact time, pH, concentration, adsorbent dosage and temperature were studied. The kinetics followed is first order in nature, and the value of rate constant was found to be 1.90×10(-2) min(-1) at 100 mg L(-1) and 303 K. Removal efficiency decreases from 99 to 87% by increasing the concentration of Ni(II) in solution from 50 to 100 mg L(-1). It was found that the adsorption of Ni(II) increases by increasing temperature from 303 to 323 K and the process is endothermic in nature. The adsorption isotherm data were fitted to Langmuir and Freundlich equation, and the Langmuir adsorption capacity, Q°, was found to be (38.3)mgg(-1). The results also revealed that nanoparticle impregnated onto tea waste from agriculture biomass, can be an attractive option for metal removal from industrial effluent.
    Matched MeSH terms: Tea/chemistry*
  3. Dinh TC, Thi Phuong TN, Minh LB, Minh Thuc VT, Bac ND, Van Tien N, et al.
    Diabetes Metab Syndr, 2019 03 15;13(2):1667-1673.
    PMID: 31336539 DOI: 10.1016/j.dsx.2019.03.021
    Obesity is one of the top global issues, which induces several serious health consequences both physically and mentally, such as type 2 diabetes, cardiovascular diseases, dyslipidemia, eating disorders, depression and stress. However, the effective therapy to prevent and treat obesity and overweight, up to now, cannot be found nowadays. Several methods/medicines namely diet control, energy balance, environmental changes, genetic and stem cell therapies, new drugs/chemicals have been extensively studied to enhance the ability to control bodyweight and prevent obesity. Of all the aforementioned methods, green tea, used as a daily beverage, has shown beneficial impacts for the health, especially its anti-obesity effects. Available evidence shows that green tea can interrupt lipid emulsification, reduce adipocyte differentiation, increase thermogenesis, and reduce food intake, thus green tea improves the systemic metabolism and decreases fat mass. Here, we highlight and sum up the update investigations of anti-obesity effect of green tea as well as discuss the potential application of them for preventing obesity and its related metabolic disorders.
    Matched MeSH terms: Tea/chemistry*
  4. Rawangkan A, Kengkla K, Kanchanasurakit S, Duangjai A, Saokaew S
    Molecules, 2021 Jun 30;26(13).
    PMID: 34209247 DOI: 10.3390/molecules26134014
    Influenza is one of the most serious respiratory viral infections worldwide. Although several studies have reported that green tea catechins (GTCs) might prevent influenza virus infection, this remains controversial. We performed a systematic review and meta-analysis of eight studies with 5,048 participants that examined the effect of GTC administration on influenza prevention. In a random-effects meta-analysis of five RCTs, 884 participants treated with GTCs showed statistically significant effects on the prevention of influenza infection compared to the control group (risk ratio (RR) 0.67, 95%CIs 0.51-0.89, P = 0.005) without evidence of heterogeneity (I2= 0%, P = 0.629). Similarly, in three cohort studies with 2,223 participants treated with GTCs, there were also statistically significant effects (RR 0.52, 95%CIs 0.35-0.77, P = 0.001) with very low evidence of heterogeneity (I2 = 3%, P = 0.358). Additionally, the overall effect in the subgroup analysis of gargling and orally ingested items (taking capsules and drinking) showed a pooled RR of 0.62 (95% CIs 0.49-0.77, P = 0.003) without heterogeneity (I2= 0%, P = 0.554). There were no obvious publication biases (Egger's test (P = 0.138) and Begg's test (P = 0.103)). Our analysis suggests that green tea consumption is effective in the prophylaxis of influenza infections. To confirm the findings before implementation, longitudinal clinical trials with specific doses of green tea consumption are warranted.
    Matched MeSH terms: Tea/chemistry*
  5. Zokti JA, Sham Baharin B, Mohammed AS, Abas F
    Molecules, 2016 Jul 26;21(8).
    PMID: 27472310 DOI: 10.3390/molecules21080940
    Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%-88.04%, 19.32-24.90 (g GAE/100 g), and 29.52%-38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%-5.11%, 0.28-0.36, 3.22%-4.71%, 0.22-0.28 g/cm³ and 40.43-225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%-188.63% and 207.55%-231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35-60, 34-65 and 231-288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.
    Matched MeSH terms: Tea/chemistry*
  6. Chen YW, Lee HV
    Int J Biol Macromol, 2018 Feb;107(Pt A):78-92.
    PMID: 28860064 DOI: 10.1016/j.ijbiomac.2017.08.143
    In the present work, four types of newly chosen municipal solid wastes (Panax ginseng, spent tea residue, waste cotton cloth, and old corrugated cardboard) were studied as the promising sources for nanocellulose, which has efficiently re-engineered the structure of waste products into highly valuable nanocellulose materials. The nanocellulose was produced directly via a facile one-pot oxidative hydrolysis process by using H2O2/Cr(NO3)3 solution as the bleaching agent and hydrolysis medium under acidic condition. The isolated nanocellulose products were well-characterized in terms of chemical composition, product yield, morphological structure and thermal properties. The study has found that the crystallinity index of the obtained nanocellulose products were significantly higher (62.2-83.6%) than that of its starting material due to the successive elimination of lignin, hemicellulose and amorphous regions of cellulose, which were in good agreement with the FTIR analysis. The evidence of the successful production of nanocellulose was given by TEM observation which has revealed the fibril widths were ranging from 15.6 to 46.2nm, with high cellulose content (>90%), depending on the cellulosic origin. The physicochemical properties of processed samples have confirmed that the isolation of high purity nanocellulose materials from different daily spent products is possible. The comparative study can help to provide a deep insight on the possibility of revalorizing the municipal solid wastes into nanocellulose via the simple and versatile one-pot isolation system, which has high potential to be used in commercial applications for sustainable development.
    Matched MeSH terms: Tea/chemistry
  7. Khaleel AK, Shaari RB, Nawi MAA, Al-Yassiri AMH
    Asian Pac J Cancer Prev, 2022 Sep 01;23(9):3195-3199.
    PMID: 36172684 DOI: 10.31557/APJCP.2022.23.9.3195
    OBJECTIVE: Green tea (GT) contains polyphenolic flavonoids, different minerals like magnesium, calcium, and zinc, vitamins, amino acids, carbohydrates, proteins, and others. It has a different health benefit. The aim of the present study was to investigate the effect of intragastric gavage of a high dose GT extract on serum biochemical analysis of magnesium, calcium, and zincin juvenile Wistar albino rats.

    METHODS: Twelve rats were used in the study and divided in to two equal groups. All the animals in the control group were intragastically gavaged by distilled water and continues for ten days, from day 24 to day 34 of age, while the animals in the study group were intragastically gavaged by GT extract (300mg/kg/day) which continues also for ten days from day 24 to day 34 of age. On day 34 of age, and two hours after the last dose, the rats were anaesthetized and blood collection by cardiac puncture was taken.

    RESULTS: The results showed that the intragastric gavage of a high dose of GT extract caused a non-significant increase in serum magnesium, and calcium levels (p>0.05), but a significant increase in zinc serum level was seen(p< 0.05).

    CONCLUSION: GT can cause a significant increase in zinc serum level, and this may explain the significant role of GT in the response to different oxidative stress. It is recommended to measure the Zn serum level in rats after a period longer than two hrs from the time of the last dose of intragastric gavage of GT extract.

    Matched MeSH terms: Tea/chemistry
  8. Brza MA, Aziz SB, Anuar H, Al Hazza MHF
    Int J Mol Sci, 2019 Aug 11;20(16).
    PMID: 31405255 DOI: 10.3390/ijms20163910
    The present work proposed a novel approach for transferring high-risk heavy metals tometal complexes via green chemistry remediation. The method of remediation of heavy metals developed in the present work is a great challenge for global environmental sciences and engineering because it is a totally environmentally friendly procedure in which black tea extract solution is used. The FTIR study indicates that black tea contains enough functional groups (OH and NH), polyphenols and conjugated double bonds. The synthesis of copper complex was confirmed by the UV-vis, XRD and FTIR spectroscopic studies. The XRD and FTIR analysis reveals the formation of complexation between Cu metal complexes and Poly (Vinyl Alcohol) (PVA) host matrix. The study of optical parameters indicates that PVA-based hybrids exhibit a small optical band gap, which is close to inorganic-based materials. It was noted that the absorption edge shifted to lower photon energy. When Cu metal complexes were added to PVA polymer, the refractive index was significantly tuned. The band gap shifts from 6.2 eV to 1.4 eV for PVA incorporated with 45 mL of Cu metal complexes. The nature of the electronic transition in hybrid materials was examined based on the Taucs model, while a close inspection of the optical dielectric loss was also performed in order to estimate the optical band gap. The obtained band gaps of the present work reveal that polymer hybrids with sufficient film-forming capability could be useful to overcome the drawbacks associated with conjugated polymers. Based on the XRD results and band gap values, the structure-property relationships were discussed in detail.
    Matched MeSH terms: Tea/chemistry*
  9. Ramasamy C
    Infect Disord Drug Targets, 2015;15(3):141-52.
    PMID: 26321324
    OBJECTIVES: Polyphenols constitute the major component in green tea, which represent a cluster known as catechins. The presence of polyphenols, especially the amino acid theanine and catechins with its antioxidant properties in green tea make them ideal for medicinal- dental applications. The objective of the paper is to delineate the role of green tea polyphenols in periodontal disease.

    METHODS: The Pub med data base was searched for human clinical studies, reviews pertinent to application of green tea polyphenols in periodontal health dating from Sep 1980- Sep 2014.

    RESULTS: The retrieved inference from the epidemiological surveys, in vitro studies and overviews of polyphenols, postulate green tea as potential natural antioxidant. Green tea mouthwashes possess limitations, which make them ineffective during the chronic stages of periodontitis. Human studies reveal that the prognosis of periodontal disease is better when the green tea catechins are used via local drug delivery.

    CONCLUSION: The maintenance of periodontal health could be enhanced by emphasizing the habit of drinking green tea in periodontitis patients. The future scope of the research demands the analysis of polyphenols at molecular level to have a better understanding of its overwhelming applications.

    Matched MeSH terms: Tea/chemistry*
  10. Chang AS, Yeong BY, Koh WP
    Nutr Rev, 2010 Apr;68(4):246-52.
    PMID: 20416020 DOI: 10.1111/j.1753-4887.2010.00283.x
    Reported here is a summary of the proceedings of the Symposium on Plant Polyphenols: Nutrition, Health and Innovations, which was cosponsored by the Southeast Asia Region branch of the International Life Sciences Institute and the Nutrition Society of Malaysia in Kuala Lumpur, Malaysia, June 22-23, 2009. The symposium provided a timely update of research regarding the protective effects of polyphenols in chronic diseases, such as cardiovascular disease and cancer, as well as the development of innovative polyphenol-containing food products with enhanced nutritive and health properties. Presentations covered polyphenols from a wide range of food sources such as tea, coffee, nuts and seeds, cocoa and chocolate, soy, and Asian fruits, vegetables, and spices. The symposium was attended by a large and diverse group of nutritionists, dietitians, researchers and allied health professionals, as well as management, research and development, and marketing personnel from the food and beverage industry. Their enthusiastic participation was a testament to the increasing awareness and interest in polyphenols in the prevention and control of chronic diseases. Presented here are some of the highlights and important information from the symposium.
    Matched MeSH terms: Tea/chemistry
  11. Jacob SA, Khan TM, Lee LH
    Nutr Cancer, 2017 Apr;69(3):353-364.
    PMID: 28287319 DOI: 10.1080/01635581.2017.1285037
    This systematic review aimed to assess the clinical benefits of green tea consumption on the progression and prevention of prostate cancer (PCa). A systematic search was performed across the following databases: PubMed, Excerpta Medica dataBASE, Database of Abstracts of Reviews of Effects, Current Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials. We included studies from database inception to September 2015. Studies must report on the effect of green tea consumption on PCa. The quality of observational studies was assessed using the Newcastle-Ottawa Scale (NOS), while randomized controlled trials (RCTs) were assessed for quality using the Jadad scale. A total of 15 articles were included, with 11 reporting on the effect of green tea consumption on PCa prevention, and four reporting on the effect of green tea on treatment. Mean NOS for observational studies was 7.4 (SD±1.3), with a range from 6 to 9, while all three RCTs scored 5 on the Jadad scale. Findings demonstrate that green tea appears to be an effective chemopreventive agent, particularly in those with high-grade prostate intraepithelial neoplasia. However, evidence of efficacy in the treatment of PCa is currently lacking. Given the limitations in current studies, more well-designed RCTs should be undertaken to determine if green tea indeed has a role in the prevention and treatment of PCa.
    Matched MeSH terms: Tea/chemistry*
  12. Eng QY, Thanikachalam PV, Ramamurthy S
    J Ethnopharmacol, 2018 Jan 10;210:296-310.
    PMID: 28864169 DOI: 10.1016/j.jep.2017.08.035
    ETHNOPHARMACOLOGICAL RELEVANCE: The compound epigallocatechin-3-gallate (EGCG), the major polyphenolic compound present in green tea [Camellia sinensis (Theaceae], has shown numerous cardiovascular health promoting activity through modulating various pathways. However, molecular understanding of the cardiovascular protective role of EGCG has not been reported.

    AIM OF THE REVIEW: This review aims to compile the preclinical and clinical studies that had been done on EGCG to investigate its protective effect on cardiovascular and metabolic diseases in order to provide a systematic guidance for future research.

    MATERIALS AND METHODS: Research papers related to EGCG were obtained from the major scientific databases, for example, Science direct, PubMed, NCBI, Springer and Google scholar, from 1995 to 2017.

    RESULTS: EGCG was found to exhibit a wide range of therapeutic properties including anti-atherosclerosis, anti-cardiac hypertrophy, anti-myocardial infarction, anti-diabetes, anti-inflammatory and antioxidant. These therapeutic effects are mainly associated with the inhibition of LDL cholesterol (anti-atherosclerosis), inhibition of NF-κB (anti-cardiac hypertrophy), inhibition of MPO activity (anti-myocardial infarction), reduction in plasma glucose and glycated haemoglobin level (anti-diabetes), reduction of inflammatory markers (anti-inflammatory) and the inhibition of ROS generation (antioxidant).

    CONCLUSION: EGCG shows different biological activities and in this review, a compilation of how this bioactive molecule plays its role in treating cardiovascular and metabolic diseases was discussed.

    Matched MeSH terms: Tea/chemistry
  13. Zamora-Ros R, Cayssials V, Jenab M, Rothwell JA, Fedirko V, Aleksandrova K, et al.
    Eur J Epidemiol, 2018 Nov;33(11):1063-1075.
    PMID: 29761424 DOI: 10.1007/s10654-018-0408-6
    Polyphenols may play a chemopreventive role in colorectal cancer (CRC); however, epidemiological evidence supporting a role for intake of individual polyphenol classes, other than flavonoids is insufficient. We evaluated the association between dietary intakes of total and individual classes and subclasses of polyphenols and CRC risk and its main subsites, colon and rectum, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The cohort included 476,160 men and women from 10 European countries. During a mean follow-up of 14 years, there were 5991 incident CRC cases, of which 3897 were in the colon and 2094 were in the rectum. Polyphenol intake was estimated using validated centre/country specific dietary questionnaires and the Phenol-Explorer database. In multivariable-adjusted Cox regression models, a doubling in total dietary polyphenol intake was not associated with CRC risk in women (HRlog2 = 1.06, 95% CI 0.99-1.14) or in men (HRlog2 = 0.97, 95% CI 0.90-1.05), respectively. Phenolic acid intake, highly correlated with coffee consumption, was inversely associated with colon cancer in men (HRlog2 = 0.91, 95% CI 0.85-0.97) and positively associated with rectal cancer in women (HRlog2 = 1.10, 95% CI 1.02-1.19); although associations did not exceed the Bonferroni threshold for significance. Intake of other polyphenol classes was not related to colorectal, colon or rectal cancer risks. Our study suggests a possible inverse association between phenolic acid intake and colon cancer risk in men and positive with rectal cancer risk in women.
    Matched MeSH terms: Tea/chemistry
  14. Wang Y, Lee SM, Dykes GA
    Biofouling, 2013;29(3):307-18.
    PMID: 23528127 DOI: 10.1080/08927014.2013.774377
    Tea can inhibit the attachment of Streptococcus mutans to surfaces and subsequent biofilm formation. Five commercial tea extracts were screened for their ability to inhibit attachment and biofilm formation by two strains of S. mutans on glass and hydroxyapatite surfaces. The mechanisms of these effects were investigated using scanning electron microscopy (SEM) and phytochemical screening. The results indicated that extracts of oolong tea most effectively inhibited attachment and extracts of pu-erh tea most effectively inhibited biofilm formation. SEM images showed that the S. mutans cells treated with extracts of oolong tea, or grown in medium containing extracts of pu-erh tea, were coated with tea components and were larger with more rounded shapes. The coatings on the cells consisted of flavonoids, tannins and indolic compounds. The ratio of tannins to simple phenolics in each of the coating samples was ∼3:1. This study suggests potential mechanisms by which tea components may inhibit the attachment and subsequent biofilm formation of S. mutans on tooth surfaces, such as modification of cell surface properties and blocking of the activity of proteins and the structures used by the bacteria to interact with surfaces.
    Matched MeSH terms: Tea/chemistry*
  15. Salleh MN, Runnie I, Roach PD, Mohamed S, Abeywardena MY
    J Agric Food Chem, 2002 Jun 19;50(13):3693-7.
    PMID: 12059144
    Twelve edible plant extracts rich in polyphenols were screened for their potential to inhibit oxidation of low-density lipoprotein (LDL) in vitro and to modulate LDL receptor (LDLr) activity in cultured HepG2 cells. The antioxidant activity (inhibition of LDL oxidation) was determined by measuring the formation of conjugated dienes (lag time) and thiobarbituric acid reagent substances (TBARS). Betel leaf (94%), cashew shoot (63%), Japanese mint (52%), semambu leaf (50%), palm frond (41%), sweet potato shoot, chilli fruit, papaya shoot, roselle calyx, and maman showed significantly increased lag time (>55 min, P < 0.05) and inhibition of TBARS formation (P < 0.05) compared to control. LDLr was significantly up-regulated (P < 0.05) by Japanese mint (67%), semambu (51%), cashew (50%), and noni (49%). Except for noni and betel leaf, most plant extracts studied demonstrated a positive association between antioxidant activity and the ability to up-regulate LDL receptor. Findings suggest that reported protective actions of plant polyphenols on lipoprotein metabolism might be exerted at different biochemical mechanisms.
    Matched MeSH terms: Tea/chemistry
  16. Yahya HM, Day A, Lawton C, Myrissa K, Croden F, Dye L, et al.
    Eur J Nutr, 2016 Aug;55(5):1839-47.
    PMID: 26210882 DOI: 10.1007/s00394-015-1001-3
    BACKGROUND: Establishing and linking the proposed health benefits of dietary polyphenols to their consumption requires measurement of polyphenol intake in appropriate samples and an understanding of factors that influence their intake in the general population.

    METHODS: This study examined polyphenol intake estimated from 3- and 7-day food diaries in a sample of 246 UK women aged 18-50 years. Estimation of the intake of 20 polyphenol subclasses commonly present in foods consumed by the sample studied was done using Phenol-Explorer(®) and USDA polyphenol databases. Women were participants in the Leeds Women's Wellbeing Study (LWW) (n = 143), a dietary intervention study aimed at overweight women (mean age 37.2 ± 9.4 years; mean BMI 30.8 ± 3.1 kg/m(2)), and the Diet and Health Study (DH) (n = 103) which aimed to examine the relationship between polyphenol intake and cognitive function (mean age 25.0 ± 9.0 years; mean BMI 24.5 ± 4.6 kg/m(2)).

    RESULTS: The estimated intake of polyphenol subclasses was significantly different between the two samples (p tea and coffee consumption. Other major polyphenol food sources included fruits, vegetables and processed foods.

    CONCLUSION: Older women consumed more polyphenol-containing foods and beverages, which was due to the higher coffee and tea consumption amongst the LWW participants.

    Matched MeSH terms: Tea/chemistry
  17. Abdulbaqi HR, Himratul-Aznita WH, Baharuddin NA
    Arch Oral Biol, 2016 Oct;70:117-124.
    PMID: 27343694 DOI: 10.1016/j.archoralbio.2016.06.011
    OBJECTIVE: Green tea (Gt), leafs of Camellia sinensis var. assamica, is widely consumed as healthy beverage since thousands of years in Asian countries. Chewing sticks (miswak) of Salvadora persica L. (Sp) are traditionally used as natural brush to ensure oral health in developing countries. Both Gt and Sp extracts were reported to have anti-bacterial activity against many dental plaque bacteria. However, their combination has never been tested to have anti-bacterial and anti-adherence effect against primary dental plaque colonizers, playing an initial role in the dental plaque development, which was investigated in this study.

    METHODS: Two-fold serial micro-dilution method was used to measure minimal inhibitory concentration (MIC) of aqueous extracts of Gt, Sp and their combinations. Adsorption to hexadecane was used to determine the cell surface hydrophobicity (CSH) of bacterial cells. Glass beads were used to mimic the hard tissue surfaces, and were coated with saliva to develop experimental pellicles for the adhesion of the primary colonizing bacteria.

    RESULTS: Gt aqueous extracts exhibited better anti-plaque effect than Sp aqueous extracts. Their combination, equivalent to 1/4 and 1/2 of MIC values of Gt and Sp extracts respectively, showed synergistic anti-plaque properties with fractional inhibitory concentration (FIC) equal to 0.75. This combination was found to significantly reduce CSH (p<0.05) and lower the adherence ability (p<0.003) towards experimental pellicles.

    CONCLUSION: Combination between Gt and Sp aqueous extracts exhibited synergistic anti-plaque activity, and could be used as a useful active agent to produce oral health care products.

    Matched MeSH terms: Tea/chemistry*
  18. Zamora-Ros R, Knaze V, Rothwell JA, Hémon B, Moskal A, Overvad K, et al.
    Eur J Nutr, 2016 Jun;55(4):1359-75.
    PMID: 26081647 DOI: 10.1007/s00394-015-0950-x
    BACKGROUND/OBJECTIVES: Polyphenols are plant secondary metabolites with a large variability in their chemical structure and dietary occurrence that have been associated with some protective effects against several chronic diseases. To date, limited data exist on intake of polyphenols in populations. The current cross-sectional analysis aimed at estimating dietary intakes of all currently known individual polyphenols and total intake per class and subclass, and to identify their main food sources in the European Prospective Investigation into Cancer and Nutrition cohort.

    METHODS: Dietary data at baseline were collected using a standardized 24-h dietary recall software administered to 36,037 adult subjects. Dietary data were linked with Phenol-Explorer, a database with data on 502 individual polyphenols in 452 foods and data on polyphenol losses due to cooking and food processing.

    RESULTS: Mean total polyphenol intake was the highest in Aarhus-Denmark (1786 mg/day in men and 1626 mg/day in women) and the lowest in Greece (744 mg/day in men and 584 mg/day in women). When dividing the subjects into three regions, the highest intake of total polyphenols was observed in the UK health-conscious group, followed by non-Mediterranean (non-MED) and MED countries. The main polyphenol contributors were phenolic acids (52.5-56.9 %), except in men from MED countries and in the UK health-conscious group where they were flavonoids (49.1-61.7 %). Coffee, tea, and fruits were the most important food sources of total polyphenols. A total of 437 different individual polyphenols were consumed, including 94 consumed at a level >1 mg/day. The most abundant ones were the caffeoylquinic acids and the proanthocyanidin oligomers and polymers.

    CONCLUSION: This study describes the large number of dietary individual polyphenols consumed and the high variability of their intakes between European populations, particularly between MED and non-MED countries.

    Matched MeSH terms: Tea/chemistry
  19. Md Nesran ZN, Shafie NH, Ishak AH, Mohd Esa N, Ismail A, Md Tohid SF
    Biomed Res Int, 2019;2019:3480569.
    PMID: 31930117 DOI: 10.1155/2019/3480569
    Epigallocatechin-3-gallate (EGCG) is the most abundant bioactive polyphenolic compound among the green tea constituents and has been identified as a potential anticancer agent in colorectal cancer (CRC) studies. This study was aimed to determine the mechanism of actions of EGCG when targeting the endoplasmic reticulum (ER) stress pathway in CRC. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay was performed on HT-29 cell line and normal cell line (3T3) to determine the EGCG toxicity. Next, western blot was done to observe the expression of the related proteins for the ER stress pathway. The Caspase 3/7 assay was performed to determine the apoptosis induced by EGCG. The results demonstrated that EGCG treatment was toxic to the HT-29 cell line. EGCG induced ER stress in HT-29 by upregulating immunoglobulin-binding (BiP), PKR-like endoplasmic reticulum kinase (PERK), phosphorylation of eukaryotic initiation factor 2 alpha subunit (eIF2α), activating transcription 4 (ATF4), and inositol-requiring kinase 1 alpha (IRE1α). Apoptosis was induced in HT-29 cells after the EGCG treatment, as shown by the Caspase 3/7 activity. This study indicates that green tea EGCG has the potential to inhibit colorectal cancer cells through the induction of ER stress.
    Matched MeSH terms: Tea/chemistry*
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