title: Antioxidant protection during the menstrual cycle: the effects of estradiol on ascorbic-dehydroascorbic acid plasma levels and total antioxidant plasma status in eumenorrhoic women during the menstrual cycle.
abstract: BACKGROUND
  Estrogens, apart from their classic role as steroid hormones, also possess significant antioxidant properties. The present study was undertaken to assess the antioxidant potential of the female during the various menstrual phases and to investigate the correlation between ascorbic acid, dehydroascorbic acid plasma levels, total antioxidant plasma status, and estradiol levels.
  
  
  METHODS
  Thirteen eumenorrhoic women were studied. Ascorbic acid and dehydroascorbic acid plasma levels, total antioxidant plasma status, estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone during time of menstruation, midfollicular phase, time of ovulation, and midluteal phase were determined. Ascorbic-dehydroascorbic acid ratio was also calculated.
  
  
  RESULTS
  A progressive significant rise in ascorbic acid plasma levels (p < 0.01), ascorbic-dehydroascorbic acid ratio (p < 0.001), and total antioxidant plasma status (p < 0.05) from menstruation to ovulation was observed. Moreover, a significant decrease in dehydroascorbic acid was found at the same phases (p < 0.05). Changes of estradiol levels during the menstrual cycle correlated positively with the changes of ascorbic acid levels and total antioxidant plasma status (p < 0.05). Furthermore, estradiol levels correlated positively with ascorbic acid levels (p < 0.05, r < 0.5), ascorbic-dehydroascorbic acid ratio (p < 0.05, r < 0.5), and total antioxidant plasma status (p < 0.05, r < 0.8) in all menstrual phases.
  
  
  CONCLUSIONS
  An elevated antioxidant protection during ovulation and the midluteal phase appears to be present in eumenorrhoic women. Moreover we observed a cyclic variation in the antioxidant parameters we assayed in the females in the present study, which could be due to cyclic changes in estradiol levels.
authors.affiliation: Laboratory of Physiology, University of Ioannina, School of Medicine, Ioannina, Greece. constantinos.michos@lg.se
authors.forename: Constantinos
authors.initials: C
authors.lastname: Michos
authors.forename: Demetrios N
authors.initials: DN
authors.lastname: Kiortsis
authors.forename: Angelos
authors.initials: A
authors.lastname: Evangelou
authors.forename: Spyridon
authors.initials: S
authors.lastname: Karkabounas
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood*; D003683:Dehydroascorbic Acid / Q000097:blood*; D004958:Estradiol / Q000097:blood*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000097:blood*; D011374:Progesterone / Q000097:blood*; D012016:Reference Values
chemical_list: D000975:Antioxidants; D011374:Progesterone; D004958:Estradiol; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid