Antioxidant Activity in Plasma and Tissues Distribution of (-)-Epigallocatechin Gallate after Oral Administration to Rats

Abstract

The aim of the present work was to examine the antioxidative effect of EGCG after administering it perorally to rats at a dose of 150 mg/kg body weight. The antioxidative activity of rat plasma, and plasma levels and tissue distribution of EGCG were determined. The results showed that oral administration of EGCG increased the antioxidative activity of rat plasma, measured by the preservation of the inner lipophilic antioxidant α-tocopherol during ex vivo oxidation by hydrophilic radical initiator, at 2nd, 5th and 24th hours post dose. The levels of the total EGCG in rat plasma were 0.82 and 0.5 μ M at 2nd and 5th hours respectively as measured by developed high-performance liquid chromatographic method with electrochemical detection (HPLC - ED). The highest levels of EGCG were detected in rat small intestine and colon and were in the range 4.75 - 24.41 nmol/g. The EGCG levels in rat kidneys, liver, spleen, lung, brain, bladder and prostate were in the range 0.1 - 1 nmol/g. In conclusion, we showed that oral administration of EGCG at a dose of 150 mg/kg body weight increased the antioxidative strength of rat plasma, preserving α-tocopherol during ex vivo oxidation. In small intestine and colon EGCG reached values having anticancer effects in cell culture experiments.