Objective: To investigate the influences of vitamin E (VE) at different dosage on peripheral blood lymphocyte (PBL) proliferation and anti-DNA oxidative damage activities and erythrocyte membrane fluidity.
Methods: 48 Wistar rats were randomly divided into four groups including control group, VE1, VE2, and VE3 groups supplemented with 7.5, 50, 200, 750 IU/kg bw x d VE, respectively. The trial lasted 8 weeks and the blood samples were collected at the end of the trial. The level of plasma VE was analyzed by fluorescent spectrometry. Plasma MDA and membrane GSH-Px were analyzed by kits. The blood erythrocyte membrane fluidity was detected by fluorescence polarization method, lymphocyte transformation rate by MTT method and DNA oxidative damage by comet assay.
Results: The results showed that plasma VE levels significantly increased in VE1, VE2, and VE3 groups. Plasma MDA and erythocyte membrane GSH-Px activity in the rats in 50 IU/kg bw x d (VE1) group were (2.29 +/- 0.55) nmol/ml and (367.17 +/- 129.86) U/mg prot, respectively. P (fluorescence polarization) and eta(microviscosity), which were inversely related with membrane fluidity, in VE1 group were significantly lower. Lymphocyte transformation rate was significantly increased by 261.86%, 199.23% and 412.97% and H2O2 induced DNA damage significantly decreased compared with the control, VE2, and VE3 groups.
Conclusion: It is indicated that an effective intake of VE for enhancing erythrocyte membrane fluidity, lymphocyte proliferation and DNA stability was 50 IU/kg bw x d, while too excessive intake of VE could not be found to be beneficial.