Plasma catechins

Widlansky, M.E., Duffy, S.J., Hamburg, N.M., Gokce, N., Warden, B.A., Wiseman, S., Keaney, J.F., Jr., Frei, B., and Vita, J.A., Effects of black tea consumption on plasma catechins and markers of oxidative stress and inflammation in patients with coronary artery disease. Free Radical Biol Med, 38, 499, 2005. 

At present, the biological activity of tea catechins has been determined mostly with the parent chemicals. EGCG, EGC, EC, and ECG have been shown to possess various biological activities, including antioxidative and free radical scavenger activity when studied in in vitro systems. " Pietta et al. reported that free plasma catechins account for only about 20% of increase in the total antioxidant activity... 

DALLUGE J J, NELSON B c, THOMAS J B, WELCH M J and SANDER L c (1997) Capillary liquid chromatography/electrospray mass spectrometry for the separation and detection of catechins in green tea and human plasma , Rapid Commun Mass Spectrom, 11, 1753-6. 

NAKAGAWA K and MIYAZAWA T (1997) Chemiluminescence-high-performance liquid chromatographic determination of tea catechin, (-)-epigallocatechm 3-gallate, at picomole levels in rat and human plasma , Anal Biochem, 248, 41-9. 

LOTiTO s B, FRAGA c G (1998) (+)-Catechin prevents human plasma oxidation, Free Radical Biology and Medicine, 24, 435-41. 

VAN HET HOF K H, WISEMAN s A, YANG c s, TiJBURG L B M (1999) Plasma and lipoprotein levels of tea catechins following repeated tea consumption, Proceedings of the Society for Experimental Biology and Medicine, 220, 203-9. 

Nowadays, consumers would like those antioxidants present in food products not only to stabilise food lipids, but also to be absorbed through the intestinal wall and protect the lipids of blood plasma against oxidation. This effect is relatively evident in the case of tocopherols (which are liposoluble) or ascorbic acid (which is hydrophilic), but much less evidence is available on antioxidants of medium polarity, such as flavonoids, rosemary oleoresins or green or black tea catechins. 

On patients with cancer, the effects of green tea catechins, soy isoflavones and quercetin as chemoprotective/chemotherapeutic agents have also been studied. Although results have not been entirely satisfactory, a partial response has been achieved in some trials. For example, small decreases in plasma concentration of prostate-specific antigen were observed in prostate cancer patients who consumed soy isoflavones. Nevertheless, results in individuals with premalignant disease who consumed green tea polyphenols support their advancement into phase III clinical intervention trials aimed at the prevention of PIN, leukoplakia, or premalignant cervical disease (Thomasset and others 2006). 

Nakagawa, K., Okuda, S., and Miyazawa, T., Dose-dependent incorporation of tea catechins, (—)-epigallocatechin-3-gallate and (—)-epigallocatechin, into human plasma, Biosci. Biotechnol. Biochem., 61, 1981, 1997. 

Kimura, M., Umegaki, K., Kasuya, Y., Sugisawa, A., and Higuchi, M., The relation between single/double or repeated tea catechin ingestions and plasma antioxidant activity in humans, Eur. J. Clin. Nutr., 56, 1186, 2002. 

Donovan, J.L., Bell, J.R., Kasim-Karakas, S., German, J.B., Walzem, R.L., Hansen, R.J., and Waterhouse, A.L., Catechin is present as metabolites in human plasma after consumption of red... 

Nakagawa, K., Ninomiya, M., Okubo, T., Aoi, N., Juneja, L.R., Kim, M., Yamanaka, K., and Miyazawa, T., Tea catechin supplementation increases antioxidant capacity and prevents phospholipid hydroperoxidation in plasma of humans, J. Agric. Food Chem., 47, 3967, 1999. 

Brunet, M.J., Blade, C., Salvado, M.J., and Arola, L., Fluman apo A-I and rat transferrin are the principal plasma proteins that bind wine catechins, J. Agric. Food Chem., 50, 2708, 2002. 

Koga, T. and Meydani, M., Effect of plasma metabolites of (+)-catechin and quercetin on monocyte adhesion to human aortic endothelial cells. Am. J. Clin. Nutr., 73, 941, 2001. 

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