The different methods of making herbal tea used in various cultures may decrease the efficiency of herbal tea, therefore the purpose of the present study was to examine the changes in antioxidant activity and metal ion concentration in aqueous extracts of “Tieguanyin Stomach Tea” obtained with different steeping times. Partial phytochemical examination, element analysis, and the determination of antioxidant properties were carried out. High Al, Cr, Mn, Ni, Pb and Ti content was observed in the tea drug. Aqueous extracts of the drug sample showed H-donor activity, reducing power and scavenging activity, depending on the steeping time and concentration. According to our findings, 5-min steeping was the least effective and redox parameters of the aqueous extracts did not change considerably between 15 and 120 min of steeping time.
WUGUO, D., XINGWANG, F. & JILAN, W. (1997): Flavonoids function as antioxidants: by scavenging reactive oxygen species or by chelating iron? Radiat. phys. Chem., 50, 271-276.
'Flavonoids function as antioxidants: by scavenging reactive oxygen species or by chelating iron? ' () 50 Radiat. phys. Chem. : 271 -276.
YANG, C.S., LIN, C.-H., CHANG, HORNG, S. & HSU, H.-C. (2000): Rapidly progressive fibrosing interstitial nephritis associated with Chinese herbal drugs. Am. J. Kidney Dis., 35, 313-318.
'Rapidly progressive fibrosing interstitial nephritis associated with Chinese herbal drugs ' () 35 Am. J. Kidney Dis. : 313 -318.
TAI, Y-T., BUT, P.P-H., YOUNG, K., LAU, C-P., JADOUL, M., DE PLAEN, J.F., COSYNS, J.P. & VAN YPERSELE DE STRIBOU, C. (1993): Adverse effects from traditional Chinese medicine. Lancet, 341, 892-893.
'Adverse effects from traditional Chinese medicine ' () 341 Lancet : 892 -893.
US RECOMMENDED DIETARY ALLOWANCES (1989): 10TH ED. NATIONAL ACADEMY PRESS, WASHINGTON. VANHERWEGHEM, J.L. (1998): Misuse of herbal remedies: the case of an outbreak of terminal renal failure in Belgium (Chinese herbs nephropathy). J. altern. complem. Med., 4, 9-13.
'Us Recommended dietary allowances (1989) 10th ed. National Academy Press, Washington. Vanherweghem, J.L. (1998): Misuse of herbal remedies: the case of an outbreak of terminal renal failure in Belgium (Chinese herbs nephropathy) ' () 4 J. altern. complem. Med. : 9 -13.
WEISBURGER, J.H. (1999): Tea and human health: the underlying mechanisms. Proc. Soc. Exp. Biol. Med., 220, 271-76.
'Tea and human health: the underlying mechanisms ' () 220 Proc. Soc. Exp. Biol. Med. : 271 -76.
SZENTMIHÁLYI, K. & THEN, M. (2000): Teas of Equiseti herba, Myrtilli folium and Salviae folium. Acta Alimentaria, 29, 43-49.
'Teas of Equiseti herba, Myrtilli folium and Salviae folium ' () 29 Acta Alimentaria : 43 -49.
SHAHIDI, F. & WANASUNDARA, P.K.J.P.D. (1995): Phenolic antioxidants. Crit. Rev. Fd Sci. Nutr., 61, 549-554.
'Phenolic antioxidants ' () 61 Crit. Rev. Fd Sci. Nutr. : 549 -554.
REDDY, M.B. & COOK, J.D. (1991): Assessment of dietary determinants of nonheme iron absorption in humans and rats. Am. J. clin. Nutr., 54, 723-728.
'Assessment of dietary determinants of nonheme iron absorption in humans and rats ' () 54 Am. J. clin. Nutr. : 723 -728.
Bányai, É., Blázovics, A. & Koczka, N. (2002): Antioxidant effect of Ginkgo biloba L. originated from Hungary. Xth Meeting of the Society for Free Radical Research International SFRR Paris. Free Rad. Biol. Med., 33, 557.
'Antioxidant effect of Ginkgo biloba L. originated from Hungary ' , , .
BLÁZOVICS, A., KOVÁCS, Á., LUGASI, A., HAGYMÁSI, K., BÍRÓ, L. & FEHÉR, J. (1999): Antioxidant defense in erythrocytes and plasma of patients with active and quiescent Crohn disease and ulcerative colitis: a chemiluminescent study. Clin. Chem., 45, 895-896.
'Antioxidant defense in erythrocytes and plasma of patients with active and quiescent Crohn disease and ulcerative colitis: a chemiluminescent study ' () 45 Clin. Chem. : 895 -896.
BRUNE, M., ROSSANDER, L. & HALLBERG, L. (1989): Iron absorption and phenolic compounds: importance of different phenolic structures. Eur. J. clin. Nutr., 43, 547-558.
'Iron absorption and phenolic compounds: importance of different phenolic structures ' () 43 Eur. J. clin. Nutr. : 547 -558.
BUT, P.P-H. (1993): Need for correct identification of herbs in herbal poisoning. Lancet, 341, 637-638.
'Need for correct identification of herbs in herbal poisoning ' () 341 Lancet : 637 -638.
BUTLER, L.G. (1989): Effects of condensed tannins on animal nutrition. -in: Hemingway, R.W. & Karchesy, J.J. (Eds) Chemistry and significance of condensed tannins. Plenum Press, New York, pp. 391-402.
Effects of condensed tannins on animal nutrition , () 391 -402.
BLÁZOVICS, A., SZENTMIHÁLYI, K., LUGASI, A., BALÁZS, A., HAGYMÁSI, K., BÁNYAI, É., THEN, M., RAPAVI, E. & HÉTHELYI, É. (2003): In vitro analysis of the properties of Beiqishen Tea. Nutrition, 19, 869-874.
'In vitro analysis of the properties of Beiqishen Tea ' () 19 Nutrition : 869 -874.
BLOIS, M.S. (1958): Antioxidant determination by the use of a stable free radicals. Nature, 4617, 1198-1200.
'Antioxidant determination by the use of a stable free radicals ' () 4617 Nature : 1198 -1200.
BRAVO, L. (1998): Polyphenols: chemistry, dietary sources, metabolism, and nutritional significance. Nutr. Rev., 56, 317-333.
'Polyphenols: chemistry, dietary sources, metabolism, and nutritional significance ' () 56 Nutr. Rev. : 317 -333.
LUGASI, A., DWORSCHÁK, E., BLÁZOVICS, A. & KÉRY Á. (1998): Antioxidant and free radical scavenging properties of squeezed juice from black radish (Raphanus sativus L. var. Niger) root. Phytother. Res., 12, 502-506.
'Antioxidant and free radical scavenging properties of squeezed juice from black radish (Raphanus sativus L. var. Niger) root ' () 12 Phytother. Res. : 502 -506.
VII. Magyar Gyógyszerkönyv (Hungarian Pharmacopoeia, 7th ed.) (1992): Medicina Könyvkiadó, Budapest.
VII. Magyar Gyógyszerkönyv (Hungarian Pharmacopoeia , ().
Máday, E., Szentmihályi, K., Then, M. & SzŐke, É. (2000): Mineral element content of chamomile. Acta Alimentaria, 29, 51-57.
'Mineral element content of chamomile ' () 29 Acta Alimentaria : 51 -57.
OYAIZU, M. (1986): Studies on products of browning reaction prepared from glucosamine. Japan J. Nutr., 44, 307-315.
'Studies on products of browning reaction prepared from glucosamine ' () 44 Japan J. Nutr. : 307 -315.
FAIRWEATHER-TAIT, S.J., PIPER, Z., FATEMIN, S.J.A. & MOORE G.R. (1991): The effect of tea on iron and aluminium metabolism in the rat. Brit. J. Nutr., 65, 61-68.
'The effect of tea on iron and aluminium metabolism in the rat ' () 65 Brit. J. Nutr. : 61 -68.
HAGYMÁSI, K., KOCSIS, I., LUGASI, A., FEHÉR, J. & BLÁZOVICS, A. (2001): Extrahepatic biliary obstruction: Can sylimarin protect liver function? Phytother. Res., 15, 1-3.
'Extrahepatic biliary obstruction: Can sylimarin protect liver function? ' () 15 Phytother. Res. : 1 -3.
CHANG, C.H., WANG, Y.M., YANG, A.H. & CHIANG, S.S. (2001): Rapidly progressive fibrosing interstitial renal fibrosis associated with Chinese herbal medications. Am. J. Nephrol., 21, 441-448.
'Rapidly progressive fibrosing interstitial renal fibrosis associated with Chinese herbal medications ' () 21 Am. J. Nephrol. : 441 -448.
Deutsches Arzneibuch (1996): Amtliche Ausgabe (DAB 10). Deutscher Apotheker Verlag, Stuttgart, Govi-Verlag GmbH, Frankfurt a.M./Eschborn, Germany.
Amtliche Ausgabe (DAB 10). Deutscher Apotheker Verlag, Stuttgart , ().
EDZARD, E. (2002): Toxic heavy metals and undeclared drugs in Asian herbal medicines. Trends pharmacol. Sci., 23, 136-139.
'Toxic heavy metals and undeclared drugs in Asian herbal medicines ' () 23 Trends pharmacol. Sci. : 136 -139.
HATANO, T., KAGAWA, H., YASUHARA, T. & OKUDA, T. (1988): Two new flavonoids and other constituents in licorice root: their relative astringency and radical scavenging effects. Chem. pharm. Bull., 36, 2090-2097.
'Two new flavonoids and other constituents in licorice root: their relative astringency and radical scavenging effects ' () 36 Chem. pharm. Bull. : 2090 -2097.
HERTOG, M.G.L. & HOLLMAN, P.C.H. (1998): Potential health effects of the dietary flavonol quercetin. Eur. J. clin. Nutr., 50, 63-71.
'Potential health effects of the dietary flavonol quercetin ' () 50 Eur. J. clin. Nutr. : 63 -71.
Héthelyi, B.É., Szabó, L.Gy., Rapavi, E., Domokos, J. & Blázovics, A. (2001): Tényeken alapuló orvoslás a fitoterápiában. (Evidence based medicine in the phytotherapy.) Olaj, Szappan, Kozmetika, 50, 67-72.
'Tényeken alapuló orvoslás a fitoterápiában. (Evidence based medicine in the phytotherapy.) ' () 50 Olaj, Szappan, Kozmetika : 67 -72.
KABELITZ, L. (1998): Heavy metals in herbal drugs. Eur. J. herb. Med., 4, 25-29.
'Heavy metals in herbal drugs ' () 4 Eur. J. herb. Med. : 25 -29.
LEUNG, A. Y. (1990): Chinese medicinals. -in: Janick, J. & Simon, J.E. (Eds) Advances in new crops. Timber Press, Portland, OR., pp. 499-510.
Chinese medicinals , () 499 -510.
LONGSTAFF, M.A. & McNAB, J.M. (1991): The effect of concentration of tannin-rich bean hulls (Vicia faba L.) on activities of lipase (EC 3.1.1.3) and α-amylase (EC 3.2.1.1) in digesta and pancreas and on the digestion of lipid and starch by young chicks. Br. J. Nutr., 66, 139-147.
'The effect of concentration of tannin-rich bean hulls (Vicia faba L.) on activities of lipase (EC 3.1.1.3) and α-amylase (EC 3.2.1.1) in digesta and pancreas and on the digestion of lipid and starch by young chicks ' () 66 Br. J. Nutr. : 139 -147.
LUGASI, A. (2000): Az élelmiszer eredetű flavonoidok potenciális egészségvédő hatása. (Potentially health-protecive effects of flavonoids having food origin.) Orv. Hetil., 141, 1751-1754.
'Az élelmiszer eredetű flavonoidok potenciális egészségvédő hatása. (Potentially health-protecive effects of flavonoids having food origin.) ' () 141 Orv. Hetil. : 1751 -1754.