TY - JOUR
T1 - Comparison of estrogen-derived ortho-quinone and para-quinol concerning induction of oxidative stress
AU - Rivera-Portalatin, Nilka M.
AU - Vera-Serrano, José L.
AU - Prokai-Tatrai, Katalin
AU - Prokai, Laszlo
N1 - Funding Information:
This work was supported by the National Institutes of Health (grant number NS44765). The authors are grateful to Drs. Alevtina D. Zharikova and Pal Perjesi for their help in developing the methods used in this study. Laszlo Prokai is the Robert A. Welch Professor of the University of North Texas Health Science Center at Fort Worth.
PY - 2007/6
Y1 - 2007/6
N2 - Ortho-quinones formed from catechol estrogens are considered prooxidants due to the production of superoxide radical anions through redox cycling via semiquinones. Para-quinols have been identified as novel metabolites of and as the major products of hydroxyl-radical scavenging by estrogens. Cycling of these compounds has also been discovered, because they are converted back to the parent estrogen via reductive aromatization in vitro and in vivo. We hypothesized that, unlike ortho-quinones, para-quinols do not induce oxidative stress due to this cycling. Like the estrogen itself, the 17β-estradiol-derived para-quinol (10β,17β-dihydroxyestra-1,4-diene-3-one) did not induce oxidative stress, as the rate of hydrogen peroxide production during the incubations of the compounds in various tissue homogenates was not significantly different from that of the control experiments performed without the addition of a test compound. We also confirmed that the estrogen metabolite estra-1,5(10)-dien-3,4,17-trione (estrone 3,4-quinone) was a profound prooxidant due to redox cycling, especially in uterine tissue. Therefore, we concluded that para-quinols do not induce oxidative stress.
AB - Ortho-quinones formed from catechol estrogens are considered prooxidants due to the production of superoxide radical anions through redox cycling via semiquinones. Para-quinols have been identified as novel metabolites of and as the major products of hydroxyl-radical scavenging by estrogens. Cycling of these compounds has also been discovered, because they are converted back to the parent estrogen via reductive aromatization in vitro and in vivo. We hypothesized that, unlike ortho-quinones, para-quinols do not induce oxidative stress due to this cycling. Like the estrogen itself, the 17β-estradiol-derived para-quinol (10β,17β-dihydroxyestra-1,4-diene-3-one) did not induce oxidative stress, as the rate of hydrogen peroxide production during the incubations of the compounds in various tissue homogenates was not significantly different from that of the control experiments performed without the addition of a test compound. We also confirmed that the estrogen metabolite estra-1,5(10)-dien-3,4,17-trione (estrone 3,4-quinone) was a profound prooxidant due to redox cycling, especially in uterine tissue. Therefore, we concluded that para-quinols do not induce oxidative stress.
KW - Estrogen metabolite
KW - Oxidative stress
KW - Redox cycling
KW - Reductive aromatization
UR - http://www.scopus.com/inward/record.url?scp=34547687410&partnerID=8YFLogxK
U2 - 10.1016/j.jsbmb.2006.11.025
DO - 10.1016/j.jsbmb.2006.11.025
M3 - Article
C2 - 17582759
AN - SCOPUS:34547687410
VL - 105
SP - 71
EP - 75
JO - Journal of Steroid Biochemistry and Molecular Biology
JF - Journal of Steroid Biochemistry and Molecular Biology
SN - 0960-0760
IS - 1-5
ER -