Effect of isolated isoflavone supplementation on ABCA1-dependent cholesterol efflux potential in postmenopausal women.
OBJECTIVE
Isoflavones may display beneficial health effects in postmenopausal women. We studied in a clinical trial whether isolated isoflavone treatment in postmenopausal women could affect reverse cholesterol transport as evaluated by adenosine triphosphate-binding cassette A1- (ABCA1), dependent cholesterol efflux from macrophages. In addition, various serum lipid and lipoprotein parameters were investigated. Furthermore, we separately assessed equol-producing and non-equol-producing women.


METHODS
Postmenopausal women (n=56) were treated with either isoflavone or placebo tablets for 3 months in a crossover design, separated by a 2-month washout period. Fifteen women were classified as equol producers, and 15 women were classified as non-equol producers. Serum samples were collected before and after each treatment period. [H]-Cholesterol-labeled J774 macrophage cells, with and without ABCA1 up-regulation, were incubated with the samples, and ABCA1-dependent cholesterol efflux and serum lipid and lipoprotein levels were assessed.


RESULTS
Serum promoted 3.1%+/-1.1% and 3.2%+/-1.1% cholesterol efflux from macrophages after isoflavone and placebo treatment, respectively. Thus, isoflavone supplementation did not affect ABCA1-dependent cholesterol efflux to serum. However, as a novel finding, isoflavone treatment increased a subclass of high-density lipoprotein, the pre-beta high-density lipoprotein levels by 18% without affecting any other serum lipid concentrations. ABCA1-facilitated cholesterol efflux and lipid parameters did not differ between equol-producing and non-equol-producing women.


CONCLUSIONS
In postmenopausal women, isolated isoflavone treatment does not affect ABCA1-dependent cholesterol efflux potential from macrophages but increases circulating pre-beta high-density lipoprotein level, which could provide beneficial vascular effects.
Badeau
Robert
R
Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Finland.
Jauhiainen
Matti
M
Metso
Jari
J
Nikander
Eini
E
Tikkanen
Matti J
MJ
Ylikorkala
Olavi
O
Mikkola
Tomi S
TS
D018528:ATP-Binding Cassette Transporters / Q000187:drug effects*; D000328:Adult; D000368:Aged; D000818:Animals; D001053:Apolipoproteins / Q000097:blood; D018592:Cross-Over Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000188:drug therapy*; D007529:Isoflavones / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D008075:Lipoproteins, HDL / Q000097:blood; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008875:Middle Aged; D008517:Phytotherapy; D017698:Postmenopause; D013025:Glycine max; D016896:Treatment Outcome; D014280:Triglycerides / Q000097:blood
D018528:ATP-Binding Cassette Transporters; D001053:Apolipoproteins; D007529:Isoflavones; D008075:Lipoproteins, HDL; D014280:Triglycerides