[Study on influence of different dosage of vitamin E on peripheral blood cell activities in rats]

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.

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.

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.

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.