Cancer prevention by tea: Evidence from laboratory studies

Yang, Chung S.; Wang, Hong; Li, Guang Xun; Yang, Zhihong; Guan, Fei; Jin, Huanyu

doi:10.1016/j.phrs.2011.03.001

Cited by 216 publications

(170 citation statements)

References 110 publications

Supporting

Mentioning

165

Contrasting

Unclassified

Order By: Relevance

“…Pesquisas têm associado o consumo de chás à redução do risco de desenvolvimento de doenças cardiovasculares, diminuindo os níveis de colesterol total e da pressão arterial. Estudos recentes realizados em animais de laboratórios demonstraram que o consumo adequado de chá pode prevenir a formação de diversos tipos de câncer, como de pele, pulmão, esô-fago, estômago, intestino delgado, cólon, bexiga, fígado, pâncreas, próstata e glândulas mamárias 9 , e também pode atuar em um sinergismo positivo com administração de drogas antitumorais 10 .…”

unclassified

Determinação da atividade antioxidante e do teor total de polifenol em amostras de chá de ervas comercializadas em sachets

Nakamura

Silva

et al. 2013

ABCS Health Sci.

View full text Add to dashboard Cite

objetivo: Os chás de ervas são tradicionalmente utilizados na medicina popular em muitas regiões do Brasil. Os chás contêm compostos antioxidantes que combatem o stress oxidativo e seu consumo tem sido associado à diminuição dos níveis de colesterol, pressão arterial e até de doenças cardiovasculares. O objetivo deste estudo foi determinar a capacidade antioxidante total, o teor total de polifenóis, o consumo (scavenging) de H 2 O 2 e a presença de outros grupos de compostos antioxidantes em 43 amostras de chás em sachets. métodos: O método CUPRAC (cupric ion reducing antioxidant capacity) foi utilizado para determinar a capacidade antioxidante total. O teor total de polifenóis foi obtido com o uso do reagente de Folin-Ciocalteu; o ensaio de scavenging baseou-se no consumo de solução de H 2 O 2 após adição do chá; e a presença de flavonóides, carotenos e catequinas foi investigada por cromatografia em papel. resultados: A capacidade antioxidante total nas amostras analisadas seguiu a ordem: camomila > hortelã > carqueja > cidreira > boldo > verde > mate > preto > branco > erva doce. O teor total de polifenóis obedeceu à sequência: branco > hortelã > preto > mate > boldo > verde > camomila > carqueja > cidreira > erva doce. As divergências encontradas entre as amostras de um mesmo grupo de chá podem ser atribuídas à época da colheita, ao tipo de solo, local de plantio, variações climáticas e partes da planta utilizadas na elaboração dos sachets. Conclusão: Concluise que todas as amostras analisadas apresentaram capacidade antioxidante e consumo de H 2 O 2 . Em apenas uma delas não foi possível detectar flavonóides, carotenos ou catequinas.Palavras-chave: chá; bebidas; polifenóis; flavonóides; carotenóides; catequinas. AbstrACt objective:Tea leaves are traditionally used in folk medicine in many regions of Brazil. They contain antioxidant compounds that can protect against oxidative stress and their regular intake have been associated with decreased of cholesterol levels, blood pressure and, thereby, with the lowered risk of coronary heart disease. The objective of this study was to determine the total antioxidant capacity, the total polyphenols content, scavenging of H 2 O 2 and presence of other groups of antioxidant compounds in 43 tea samples packed in bags. methods: The CUPRAC method (cupric ion reducing antioxidant capacity) was used to quantify the total antioxidant capacity. The polyphenols content was performed using the Folin-Ciocalteu reagent. The scavenging assay was based on the consumption of H 2 O 2 after addition of tea; the presence of flavonoids, carotenes and catechins was evaluated by paper chromatography. results: The total antioxidant capacity found in tea samples followed the order: chamomile > mint > carqueja > balm > boldo > green > mate > black > white > fennel. For total polyphenol content the order was: white > mint > black > matte > boldo > green > chamomile > carqueja > balm > fennel. The differences found in the samples from the same kind of tea can be attributed to the harvest seaso...

show abstract

unclassified

Determinação da atividade antioxidante e do teor total de polifenol em amostras de chá de ervas comercializadas em sachets

Nakamura

Silva

et al. 2013

ABCS Health Sci.

View full text Add to dashboard Cite

show abstract

“…Many animal models have been demonstrated that the green tea catechins against carcinogenesis at different organ sites (Yang et al, 2011), and this conclusion is supported by many epidemiological studies. However, there are also some published studies had come to the meaningless or opposite conclusions, and individual studies may be underpowered to detect the effect of different tumor site of CRC.…”

Section: Introductionmentioning

confidence: 79%

Association Between Green Tea and Colorectal Cancer Risk: A Meta-analysis of 13 Case-control Studies

Wang

Zeng²,

Duan³

et al. 2012

Asian Pacific Journal of Cancer Prevention

View full text Add to dashboard Cite

Objective: Experimental studies have suggested green tea to be a chemopreventive agent for colorectal cancer, and many studies have examined possible associations. However, the conclusions were inconsistent or even contradictory, so we performed a meta-analysis based on published case-control studies to explore if green tea is indeed a protective factor. Methods: PubMed was searched up to May 10 th , 2012 for relevant studies, and references of included studies were manually searched. Finally 13 eligible studies, involving 12,636 cases and 38,419 controls were identified. After data extraction, a meta-analysis was performed using CMA v2 software. Results: The results indicated there may be a weak but not statistically significant reduced risk of colorectal cancer with high dose of green tea intake (OR=0.95, 95% CI:0.81-1.11, p=0.490.69-0.98). This protective effect was also found in all subgroups, except in American and European populations. Sensitivity analysis indicated the result to be robust. Publication bias was not detected by either funnel plot or Egger tests. Conclusion: The results of this meta-analysis indicate a weak lower tendency for colorectal cancer development with green tea consumption, but available epidemiologic data are insufficient to conclude that green tea may protect against colorectal cancer in humans.

show abstract

“…Additional mechanisms for Polyphenols in which they minimize oxidation level besides direct role as antioxidants [23]. Binding of metal ions such as iron and copper and prevents its participation in oxidation reactions (leading to the formation of hydroxyl radical) [24]. Prevention of redox sensitive transcription factors activation that amongst others things serve as mediators of infl ammatory reactions [25].…”

Section: Discussionmentioning

confidence: 99%

Effect of Aqueous Extracts of Green Tea in Arsenic induced Toxicity in Mice

Fatmi¹,

Fatima²,

Shahzada³

et al. 2017

Open J Plant Sci

View full text Add to dashboard Cite

Ground water arsenic contamination is a global problem affecting thousands of people worldwide, thus present study was aimed to evaluate the hypothesis that green tea extracts, having high polyphenolic content, might be able to combat the oxidative cellular damage caused by arsenic toxicity and to prevent further development of free radicals.In the present study treatment groups received sodium arsenite orally at the dose of 3 mg kg-1 body weight daily for 4 weeks followed by administration of Camellia sinensis (green tea) 300 mg kg-1 body weight daily by gavage method for 6 weeks. Their biochemical levels like liver and kidney function tests were assayed and were found with elevated levels. Furthermore, their free radical assessment like lipid peroxidation levels were assayed which was found to be many folds higher. But, after administration of aqueous extract of green tea, there was signifi cant amelioration in the biochemical and lipid peroxidation levels. The protective effect of these antioxidants was shown in the form of normalization of enzymatic and non-enzymatic activities represented by normalization of liver and kidney functions.

show abstract

Cancer prevention by tea: Evidence from laboratory studies

Cited by 216 publications

References 110 publications

Determinação da atividade antioxidante e do teor total de polifenol em amostras de chá de ervas comercializadas em sachets

Determinação da atividade antioxidante e do teor total de polifenol em amostras de chá de ervas comercializadas em sachets

Association Between Green Tea and Colorectal Cancer Risk: A Meta-analysis of 13 Case-control Studies

Effect of Aqueous Extracts of Green Tea in Arsenic induced Toxicity in Mice

Contact Info

Product

Resources

About