Dietary vitamin E prophylaxis and diabetic embryopathy: morphologic and biochemical analysis.
OBJECTIVE
In this study we sought to determine whether dietary supplementation with vitamin E, a known antioxidant, would reduce the incidence of diabetic embryopathy in an in vivo rat model.


METHODS
Eighty-day-old Sprague-Dawley rats were assigned to one of five groups: two control groups (groups 1 and 2) and three diabetic groups (groups 3, 4, and 5). One group of controls (group 2) and one group of diabetic rats (group 4) received dietary supplements of vitamin E (440 mg/day). The other three groups (groups 1, 3, and 5) received a normal diet only. Group 5 received insulin therapy to control glucose levels. On day 6 of gestation diabetes was induced in groups 3, 4, and 5 with streptozotocin (65 mg/kg). Animals were killed on day 12; embryos were examined for size, protein content, evidence of malformations, and superoxide dismutase activity.


RESULTS
In both groups (groups 3 and 4) of diabetic rats the mean blood glucose level than was significantly higher in controls. Insulin-treated animals (group 5) had glucose levels that were comparable to those of controls. The unsupplemented diabetic group had a neural tube defect rate of 21.48% +/- 9.6% (percentage of neural tube defects per rat) and a resorption rate of 21.37% +/- 20.39% (percentage of resorptions per rat) as compared with rates in the supplemented diabetic group of 6.92% +/- 4.08% and 2.17% +/- 3.74%, respectively (p < 0.01). Groups 1, 2, and 5 had similar neural tube defect rates (6.63% +/- 5.0%, 5.01% +/- 4.87%, and 3.55% +/- 5.92%, respectively. Vitamin E levels, measured by high-performance liquid chromatography, were significantly higher in maternal serum and embryos in the supplemented groups (p < 0.001) than in controls. Superoxide dismutase activity was reduced in the diabetes groups and was not affected by vitamin E therapy.


CONCLUSIONS
Supplementation with the antioxidant vitamin E confers a significant protective effect against diabetic embryopathy and may potentially serve as a dietary prophylaxis in the future. We postulate that this protective effect is mediated by a reduction in the oxidative load induced by hyperglycemia.
Sivan
E
E
Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, Temple University, Philadelphia, PA 19140, USA.
Reece
E A
EA
Wu
Y K
YK
Homko
C J
CJ
Polansky
M
M
Borenstein
M
M
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000150:complications* / Q000188:drug therapy*; D004032:Diet; D005260:Female; D005327:Fetal Resorption / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D015994:Incidence; D007328:Insulin / Q000627:therapeutic use; D009436:Neural Tube Defects / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D011247:Pregnancy; D011254:Pregnancy in Diabetics; D051381:Rats / Q000196:embryology; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000097:blood; D014810:Vitamin E / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use
D007328:Insulin; D014810:Vitamin E; D013482:Superoxide Dismutase