Address of Corresponding Author

Annals of Nutrition & Metabolism 2005;49:118-124 (DOI: 10.1159/000084745)

  Key Words

• Green tea decoction
• Iron
• Zinc
• Selenium
• Glutathione peroxidase activity, whole blood

  Abstract

Aims: The objective was to examine the effect of green tea decoction given at two different concentrations on the long-term (6 weeks) iron, zinc and selenium status of rats. Methods: During the experimental period, the rats were given ad libitum a basic diet + ultra pure water (control group), a basic diet + green tea decoction prepared from 50 g/l (tea 50 group), or a basic diet + green tea decoction prepared from 100 g/l (tea 100 group). The zinc and iron status was evaluated by determining their concentrations in the serum, blood precipitate, liver, spleen, femur, heart and kidney. Selenium status was evaluated by the serum selenium concentration and whole blood glutathione peroxidase activity. Results: Green tea decoction significantly reduced serum iron by 26% in the tea groups (p < 0.01). The blood precipitate of iron was significantly decreased by 25 and 41% in the tea 50 and tea 100 groups (p < 0.01), respectively. The reserve of iron stored in the liver, spleen and femur was significantly reduced in the tea 100 group by 32% (p < 0.02), 20% (p < 0.04) and 35% (p < 0.005), respectively. Moreover, the two concentrations of green tea significantly decreased the reserve of iron stored in the kidney (p < 0.005) and heart (p < 0.02). In contrast with its effects on iron status, green tea decoction significantly increased the serum zinc in the tea 100 group by 24% (p < 0.001). It also increased the blood precipitate of zinc by 50 (p < 0.01) and 75% (p < 0.0001) in tea 50 and tea 100 groups, respectively. In the kidney, heart and femur, zinc significantly increased in the tea groups dependent on the tea dose. Similarly, the high concentration of green tea decoction significantly increased the serum selenium concentration by 16% (p < 0.004). In addition, both concentrations of green tea decoction significantly increased the whole blood glutathione peroxidase activity by 102 and 130% (p < 0.01). Conclusion: Green tea decoction reduced the iron status and improved the zinc and selenium status of rats. These effects may constitute another beneficial effect of the green tea decoction which could play an important role in the antioxidant processes.

Copyright © 2005 S. Karger AG, Basel

  Author Contacts

Mohamed Hédi Hamdaoui
Ecole Supérieure des Sciences et Techniques de la Santé de Tunis
BP 176 Bab-Souika
TN-1006 Tunis (Tunisia)
Tel. +216 71 562 455, Fax +216 71 570 062, E-Mail hamdaoui.medhedi@gnet.tn

  Article Information

Received: April 1, 2003
Accepted: July 14, 2004
Published online: March 29, 2005
Number of Print Pages : 7
Number of Figures : 0, Number of Tables : 5, Number of References : 33