The effects of supplemental vitamin E on hematological parameters in a rat model of ovarian hormone deficiency

Objective: Menopause is associated with adverse changes in hematological parameters. Although the antioxidative and anti-inflammatory properties of vitamin E have been previously demonstrated, the effects of vitamin E on hematopoietic parameters are not well-documented. This study investigated the effects of supplemental vitamin E on hematological parameters in a rat model of ovarian hormone deficiency. Methods: Twelve-month-old female Sprague-Dawley rats were either sham-operated (Sham) or ovariectomized (Ovx). Animals were randomly divided among five treatment groups (n = 12/group) as follows: Sham; Ovx; Ovx + 300, Ovx + 525, or Ovx + 750 mg/kg diet of vitamin E for 100 days. Results: Compared with Sham, ovariectomy increased leukocyte subpopulation counts including lymphocytes (2.01 x 10(3)/mm(3); 95% confidence interval [CI] 0.11, 4.03; P = 0.03), monocytes (0.35 x 10(3)/mm(3); 95% CI 0.60, 0.11; P = 0.01), neutrophils (0.72 x 10(3)/mm(3); 95% CI 0.26, 1.19; P = 0.01), eosinophils (0.07 x 10(3)/mm(3); 95% CI 0.12, 0.30; P = 0.00), and basophils (0.13 x 10(3)/mm(3); 95% CI 0.04, 0.21; P = 0.02). Medium dose (MD) (-0.26 x 10(3)/mm(3); 95% CI -0.47, -0.05; P = 0.007) and high dose (HD) (-0.22 x 10(3)/mm(3); 95% CI -0.43, -0.01; P = 0.037) supplemental vitamin E attenuated Ovx-induced increases in monocyte counts. Low dose (LD) (-0.55 x 10(3)/mm(3); 95% CI -0.95, -0.15; P = 0.003), MD (-0.61 x 10(3)/mm(3); P = 0.001), and HD (-0.54 x 10(3)/mm(3); 95% CI -0.95, -0.14; P = 0.004) supplemental vitamin E attenuated Ovx-induced increases in neutrophil counts. LD (-0.05 x 10(3)/mm(3); 95% CI -0.08, -0.11; P = 0.006), MD (-0.05 x 10(3)/mm(3); 95% CI -0.08, -0.11; P = 0.005), and HD (-0.05 x 10(3)/mm(3); 95% CI -0.09, -0.01; P = 0.004) supplemental vitamin E also attenuated the Ovx-induced increase in eosinophil counts. Only LD (-0.09 x 10(3)/mm(3); 95% CI -0.17, -0.02; P = 0.009) supplemental vitamin E attenuated the Ovx-induced increase in basophil counts. The remaining hematological parameters assessed were not significantly affected by ovariectomy or supplemental vitamin E. Conclusion: These findings suggest that vitamin E in the form of a-tocopherol acetate may provide protection against ovarian hormone deficiency-associated adverse changes in hematological parameters.