Natural Antimutagens. Chemopreventive Action of L-Ascorbic Acid and Green Tea Infusions on the Acute Toxicity and Mutagenicity of Reaction Mixtures Nitrite-Sulfonamide

2019 ◽  
pp. 46-90
Author(s):  
Ana Pontoriero ◽  
Marcela Rizzotto
Keyword(s):  
Ascorbic Acid ◽  
Acute Toxicity ◽  
Green Tea ◽  
Tea Infusions

Stabilizing Effect of Ascorbic Acid on Green Tea Catechins

1998 ◽  
Vol 46 (7) ◽  
pp. 2512-2516 ◽  
Author(s):  
Zhen-Yu Chen ◽  
Qin Yan Zhu ◽  
Yeun Fan Wong ◽  
Zesheng Zhang ◽  
Hau Yin Chung
Keyword(s):  
Ascorbic Acid ◽  
Green Tea ◽  
Tea Catechins ◽  
Green Tea Catechins ◽  
Stabilizing Effect

Dissipation, Processing, Leaching, and Safety Evaluation of Flonicamid and Its Metabolites in Tea

2020 ◽  
Vol 103 (6) ◽  
pp. 1441-1450
Author(s):  
Ya Yang ◽  
Xiangwu Liu ◽  
Qingtao Zhang ◽  
Ya Chen ◽  
Sumei Zhang ◽  
...  
Keyword(s):  
Green Tea ◽  
High Performance ◽  
Alcoholic Beverage ◽  
Safety Evaluation ◽  
Tea Infusions ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass ◽  
Chinese Consumer ◽  
Transfer Behavior ◽  
Single Factor Analysis

Abstract Background Tea is a popular traditional non-alcoholic beverage worldwide. Flonicamid is a selective systemic pyridine carboxamide insecticide that is widely used for controlling tea leafhopper in tea. Objective The leaching rates, dissipation dynamics, and residue levels of flonicamid and its metabolites in tea leaves during processing and transferring were investigated to validate the safe risk in tea and transfer behavior using high performance liquid chromatography–tandem mass spectrometry with a convenient pretreatment method. Method The extracting method and immersion rate experiments were optimized by single factor analysis and orthogonal tests. The acetonitrile extracting solvent with 0.5% formic acid was used and optimal leaching conditions were obtained with a regime of 15 min immersion time, 100°C temperature, three immersions and a tea-to-water ratio of 1:50. Results Average recoveries in processed green tea and infusions were 80.85–98.75% with relative standard deviations <5.87%. LODs and LOQs of flonicamid, 4-trifluoromethylnicotinic acid (TFNA), N-(4-trifluoromethylnicotinoyl) glycine (TFNG), and 4-trifluoromethylnicotinamide (TFNA-AM) were 0.0013–0.350 and 0.004–1 μg/g, respectively. The processing factor of flonicamid was 0.36–5.52 during green tea manufacture. The leaching rates were 22.9-97.4% from processed tea to infusion. Conclusions The risk of long-term and short-term dietary intake of flonicamid was safe in tea infusions with the risk quotient (RQ) values <1 for the Chinese consumer. This work may provide guidance for safe and reasonable consumption of flonicamid in tea in China. Highlights The suitable leaching factors of flonicamid and its metabolites in tea infusions were optimized by orthogonal experimentation for the first time.

scholarly journals Green Tea Daily Consume Reduced Free Radicals on Moderate Smokers

2018 ◽  
Vol 2 (2) ◽  
pp. 39
Author(s):  
Rosyanne Kushargina ◽  
Rimbawan Rimbawan ◽  
Budi Setiawan
Keyword(s):  
Free Radicals ◽  
Experimental Design ◽  
Antioxidant Capacity ◽  
Green Tea ◽  
Black Tea ◽  
Intervention Period ◽  
Tea Leaves ◽  
Positive Effects ◽  
Tea Infusions ◽  
Total Antioxidant

<p><em>Smoking </em><em>can </em><em>enhance </em><em>free radicals on blood plasma. Many previous studies proved that tea is a source of antioxidants which might reduce free radicals. Green tea is known to have the higher antioxidant capacity compared to </em><em>black tea</em><em>.</em><em> This study aim</em><em>s </em><em>to analyze the effect </em><em>of green tea on reduction of free radicals on moderate smokers</em><em>, using a pre-post experimental design. </em><em>Green tea infusions were prepared with commercially available dried tea leaves (Green Tea Gamboeng Series) from the </em><em>Research</em><em> </em><em>Centers of Tea</em><em> </em><em>and</em><em> </em><em>Cinchona</em><em> Gambung, West Java. </em><em>Nine moderate smokers (11-21 cig/day) aged 30-45 years were instructed to drink 200 ml green tea three times a day for </em><em>four</em><em> weeks. Total Antioxidant Capacity (TAC) of blood serum was measured at baseline and after four weeks intervention period. The level of TAC significantly increased from 1.18 m mol/L to 1.34 m mol/L after </em><em>four</em><em> weeks intervention (P=0.000). These results prove that drinking 200 ml of green tea </em><em>three</em><em> times a day for </em><em>four</em><em> weeks has a significant benefit reduc</em><em>ing f</em><em>ree radicals of moderate smokers. Moderate smokers are advised to consume green tea continuously to sustain these positive effects.</em><em></em></p>

In Vitro and In Vivo Antitumorigenic Activity of a Mixture of Lysine, Proline, Ascorbic Acid, and Green Tea Extract on Human Breast Cancer Lines MDA-MB-231 and MCF-7

2005 ◽  
Vol 22 (2) ◽  
pp. 129-138 ◽  
Author(s):  
M. Waheed Roomi ◽  
Vadim Ivanov ◽  
Tatiana Kalinovsky ◽  
Aleksandra Niedzwiecki ◽  
Matthias Rath
Keyword(s):  
Breast Cancer ◽  
Ascorbic Acid ◽  
Green Tea ◽  
Human Breast Cancer ◽  
Human Breast ◽  
Antitumorigenic Activity ◽  
Tea Extract ◽  
Mcf 7

Green tea leaves extract with low concentration of EGCG can provide health benefits without causing renal damage

2021 ◽  
Vol 50 (3) ◽  
pp. 369-382
Author(s):  
D. Das ◽  
S. Tamuly ◽  
M. Das Purkayastha ◽  
B. Dutta ◽  
C. Barman ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Green Tea ◽  
Oral Delivery ◽  
Histopathological Examination ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Tea Leaves ◽  
Green Tea Leaves

AbstractGreen tea or its concentrated extract is coveted for its health promoting catechin-like polyphenols, especially epigallocatechin-3-gallate (EGCG). However, its amicable efficacy is now being doubted considering the recent occurrence of several cases of hepato- and nephrotoxicity, after the ingestion of EGCG-fortified (≥85–90%) nutritional supplements. Therefore, the current study was carried out to ascertain the effect of green tea leaves extract (GTE), having low EGCG content (73.8%), on liver and kidney functions of male Wistar rats using various in vivo experiments and in vitro radical scavenging activity. In terms of acute toxicity, GTE was observed to be safe when delivered at a dosage of 2000 mg kg−1 body weight (BW). Oral delivery of GTE for 28 days at a concentration of 200 mg kg−1 BW/day did not trigger sub-acute toxicity to the liver and kidneys, as per serum biochemical analyses and histopathological examination. In contrast, GTE counteracted the effects of carbon tetrachloride (a potent hepato-degenerative compound) on the liver. Furthermore, increase in high-density lipoprotein―cholesterol with concomitant lowering of serum triglycerides and low-density lipoprotein―cholesterol were noticed in GTE-treated rats. These findings suggest that low EGCG containing GTE, with appreciable antioxidant activity (IC50 = 53.18–71.28 μg mL−1), can serve as a hepatoprotective, hypolipidemic, and hypocholesterolemic ingredient.

scholarly journals Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions

2015 ◽  
Vol 52 (10) ◽  
pp. 6639-6646 ◽  
Author(s):  
Sena Saklar ◽  
Erdal Ertas ◽  
Ibrahim S. Ozdemir ◽  
Bulent Karadeniz
Keyword(s):  
Green Tea ◽  
Sensory Acceptance ◽  
Tea Infusions

Screening of the antioxidant properties and polyphenol composition of aromatised green tea infusions

2012 ◽  
Vol 92 (11) ◽  
pp. 2244-2249 ◽  
Author(s):  
Anna Pȩkal ◽  
Paulina Dróżdż ◽  
Magdalena Biesaga ◽  
Krystyna Pyrzynska
Keyword(s):  
Green Tea ◽  
Antioxidant Properties ◽  
Tea Infusions

scholarly journals Influence of phenolic compounds on sensory parameters of tea infusions

2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S195-S198
Author(s):  
P. Košulič ◽  
J. Pokorný ◽  
Z. Panovská
Keyword(s):  
Phenolic Compounds ◽  
Green Tea ◽  
Black Tea ◽  
Total Polyphenols ◽  
Iso Standards ◽  
Tea Infusions ◽  
Sensory Parameters

A set of 9 black teas and 10 green teas were analyzed. Sensory parameters of tea infusions were correlated with the content of total polyphenols (determined after Folin and Ciocalteu) and sensory parameters (determined after ISO standards). Total polyphenols affect both the astringency and the bitterness of green tea and black tea infusions. The relations are mainly semilogarithmic, but very close to linear. Sucrose decreased the astringency by 30–40%, and the bitterness was suppressed still more.

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