Protective activity of different concentration of tea polyphenols and its major compound EGCG against whole body irradiation-induced injury in mice

Objective: To evaluate the different concentrate of tea polyphenols (TP) and its compound for irradiation-protection and investigate its mechanism. Method: To evaluate the radioprotective activity, mice were exposed to whole body gamma irradiation. TP 80 and TP 50 (50, 10 mg·kg^-1) and its major constituent epigallocatechin gallate (EGCG) (50, 10 mg·kg ^-1) were administered after irradiation to examine its inhibition against irradiation-induced injury. Result: This study indicate that in comparison with non-irradiated controls, irradiation resulted in a significant reduction the spleen index (spleen weight/body weight 100), haematological parameters (RBC, WBC and PLT), activity of superoxide dismutase (SOD), and increase of malondialdehde (MDA) level in 28 days. Oral administration of TP (50 mg·kg^-1) shown the best effect on reducing the irradiation-induced injury on mice studied, and showed a protective effect against irradiation-induced haematological parameters (RBC, WBC and PLT), the spleen index and MDA level significant reduction, and antioxidase activity (SOD) decrease. Conclusion: The results suggest that TP 50 mg·kg^-1 and EGCG have in vivo antioxidant potential and radioprotective activity against whole body gamma irradiation in mice. It may be concluded that TP (50% EGCG) possess good irradiation-protective and antioxidant effect.