Tea is the second most consumed beverage in the world, next to water. The popularity of tea is determined by healthy properties connected with the presence of antioxidants, hence tea can be classified as functional food. Cadmium (Cd) and lead (Pb) are toxic metals commonly occurring in the human environment with exposure ~5 and 35 mg/kg Bw per week respectively.
Thirty growing male Wistar rats (12 weeks old, 326.4±31.0 g) were used. Rat were fed ad libitum with common laboratory animal feed mixed with 7 mg of Cd (CdCl2) and 50 mg of Pb (CH3COO)2Pb) per kg of feed. The level of metals supplied in the feed was calculated to ensure that the daily supply of Cd and Pb did not exceed the environmental exposure of humans. Then, rats were divided into the control group (n=10) and black tea (BT; n=10) or white tea (WT; n=10) supplemented groups. The rats were euthanized at the age of 24 week to analyze femora in bone morphometry and geometry (A, cross section area; IC, cortical index; and MRWT, mean relative wall thickness) as well as maximum elastic strength (Wy) and ultimate strength (Wf).
Obtained results showed significant increase of IC (about 21.7% in both groups). Moreover, Wy increased by 37% and 65% in BT and WT group respectively. Similarly, Wf increased by 30 and 25% in BT and WT group respectively. While, MRWT decreased by 21.7% in both, BT and WT groups when compared to the control bone (all P<0.05).
All these results indicate that the administration of black or weight tee improves geometrical and mechanical properties of bones in growing rats exposed to cadmium and lead.
Declaration of interest: There is no conflict of interest.
17 - 20 May 2014
European Calcified Tissue Society