Antimutagenic activity of green tea and black tea extracts studied in a dynamic in vitro gastrointestinal model

Krul, Cyrille; Luiten-Schuite, A.; Tenfelde, Aschwin; Ommen, Ben van; Verhagen, Hans; Havenaar, R.

doi:10.1016/s0027-5107(00)00158-5

Cited by 75 publications

(47 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An in vitro gastrointestinal model to simulate the conditions in the human digestive tract demonstrated that addition of milk to tea inhibited its antimutagenic activity. 25 Tea possesses strong antioxidant properties, in vitro and in vivo, that are affected by addition of milk. 26,27 In analogy, consumption of dark chocolate that contains epicatechin, but not milk chocolate or dark chocolate with extra milk, increased the antioxidant capacity of human blood plasma.…”

Section: Discussionmentioning

confidence: 99%

Addition of milk prevents vascular protective effects of tea

Lorenz

Jochmann

Krosigk

et al. 2006

European Heart Journal

151

View full text Add to dashboard Cite

Aims Experimental and clinical studies indicate that tea exerts protection against cardiovascular diseases. However, a question of much debate is whether addition of milk modifies the biological activities of tea. We studied the vascular effects of tea, with or without milk, in humans and elucidated the impact of individual milk proteins in cell culture experiments, with isolated rat aortic rings and by HPLC analysis.Methods and results A total of 16 healthy female volunteers consumed either 500 mL of freshly brewed black tea, black tea with 10% skimmed milk, or boiled water as control. Flow-mediated dilation (FMD) was measured by high-resolution vascular ultrasound before and 2 h after consumption. Black tea significantly improved FMD in humans compared with water, whereas addition of milk completely blunted the effects of tea. To support these findings, similar experiments were performed in isolated rat aortic rings and endothelial cells. Tea induced vasorelaxation in rat aortic rings and increased the activity of endothelial nitric oxide synthase by phosphorylation of the enzyme in endothelial cells. All effects were completely inhibited by the addition of milk to tea. Of the various kinds of milk proteins, the caseins accounted for these inhibiting effects of milk, probably by formation of complexes with tea catechins. Conclusion Milk counteracts the favourable health effects of tea on vascular function. This finding indicates the need for particular awareness in the interpretation and design of studies comprising nutritional flavonoids.

show abstract

Section: Discussionmentioning

confidence: 99%

Addition of milk prevents vascular protective effects of tea

Lorenz

Jochmann

Krosigk

et al. 2006

European Heart Journal

151

View full text Add to dashboard Cite

show abstract

“…There is some evidence that dietary milk proteins may bind tea polyphenols and inhibit absorption, thereby altering bioavailability and the physiological effects of tea in vivo [102]. Other authors, however, found little influence of milk on plasma tea polyphenol concentrations in humans [40,103].…”

Section: Discussionmentioning

confidence: 99%

The role of tea and tea flavonoids in cardiovascular health

Stangl¹,

Lorenz

Stangl

2006

Molecular Nutrition Food Res

214

137

View full text Add to dashboard Cite

Consumption of green or black tea has been inversely associated with the development and progression of cardiovascular diseases. In this review, the current knowledge about protective effects of tea and tea constituents, particularly flavonoids, on the cardiovascular system is summarized. Underlying mechanisms for the beneficial effects of tea include vasculoprotective, antioxidative, antithrombogenic, anti-inflammatory, and lipid-lowering properties of tea flavonoids. Although promising experimental data on beneficial effects of tea in various cardiovascular diseases are available, results of clinical studies in humans are not uniform. A number of factors are discussed which may contribute to inconsistent data in humans. Overall, tea represents a promising tool for the prevention and treatment of cardiovascular disorders.

show abstract

“…The antimutagenicity of tea extracts against IQ and Glu-P-1 in S. typhimurium TA 100 showed a significant correlation to the contents of catechins and ascorbic acid, whereas against Trp-P-1 in TA98 or TA100 correlation was high with caffeine contents [151]. Antimutagenic activity of extracts of black tea and green tea was analyzed in in vitro gastrointestinal model, which simulates the conditions in the human digestive tract [152]. In this study, dialysate from the jejunal compartment due to introduction of black and green tea, inhibited the mutagenicity of the food mutagen MeIQx (max.…”

Section: Beverages From Tea Leaves and Rose-petalmentioning

confidence: 99%

Fruits and Vegetables as Dietary Sources of Antimutagens

Gautam¹,

Saxena²,

Kumar³

2016

J Food Chem Nanotechnol

View full text Add to dashboard Cite

Mutation is the process leading to heritable changes in the genetic material of an organism and caused mainly by the external factors, including chemical and physical agents, or can also occur spontaneously due to errors in DNA replication, repair, and recombination. Agents contributing to the mutagenic burden in the environment could be from industrial sources, wide spectrum applications of biocides in the agriculture, and other contaminants. As many of these mutagenic chemicals can induce severe disorders in humans including cancer and a large spectrum of inherited diseases, it is important to detect such mutagenic agents precisely and rapidly, and also look for an approach to combat them. Natural occurring dietary antimutagens primarily from health protective foods such as fruits and vegetables could provide a mechanism to counteract the deleterious effect of these mutagens. The World Health Organization (WHO) indicates that one-third of all cancer deaths are preventable and that diet is closely linked to cancer prevention. These health protective phytochemicals particularly antimutagenic ones could provide an effective solution to these concerns. The current review deals with understanding of the mutagenic events, methods of its analysis and a brief compilation of the existing scientific findings related to the dietary sources having potential to counteract the effects of the mutagenic exposures from different sources. The review would provide an opportunity to look into the science, think about the possible future perspectives and mechanism to translate the outcome of the scientific research for benefits of the mankind.

show abstract

Antimutagenic activity of green tea and black tea extracts studied in a dynamic in vitro gastrointestinal model

Cited by 75 publications

References 30 publications

Addition of milk prevents vascular protective effects of tea

Addition of milk prevents vascular protective effects of tea

The role of tea and tea flavonoids in cardiovascular health

Fruits and Vegetables as Dietary Sources of Antimutagens

Contact Info

Product

Resources

About