Effects of equol on oxidized low-density lipoprotein-induced apoptosis in endothelial cells.
OBJECTIVE
Equol is the main active product of daidzein metabolism, produced via specific microflora in the gut. This study aimed to clarify the effects of equol on oxidized low-density lipoprotein (OX-LDL)-stimulated apoptosis in human umbilical vein endothelial cells (HUVECs).


METHODS
HUVECs were cultured in the presence of OX-LDL, and cell apoptosis was monitored by evaluating of DNA fragmentation and the production of cytoplasmic histone-associated DNA fragments. We simultaneously evaluated the level of cellular superoxide and nitric oxide (NO) and the effects of the anti-oxidant activity of equol on apoptosis.


RESULTS
We found that equol inhibited the induction of apoptosis in response to exposure of HUVECs to OX-LDL. Treatment of cells with equol led to a significant reduction in superoxide production by NAD(P)H oxidase and also to a significant increase in NO production. We further observed an effect of equol on the suppression of OX-LDL uptake.


CONCLUSIONS
These results suggested that equol might contribute to a reduced level of OX-LDL-stimulated apoptosis linked to the reduced generation of intracellular reactive oxygen species (ROS).
Kamiyama
Masumi
M
Food Processing Technology Division, Department of Food Technology, Nagano Prefecture General Industrial Technology Center, Nagano City, Nagano 380-0921, Japan. kamiyama-masumi-r@pref.nagano.jp
Kishimoto
Yoshimi
Y
Tani
Mariko
M
Utsunomiya
Kazunori
K
Kondo
Kazuo
K
D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D042783:Endothelial Cells; D004730:Endothelium, Vascular / Q000166:cytology; D060754:Equol; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology*; D008077:Lipoproteins, LDL / Q000502:physiology*; D009569:Nitric Oxide / Q000096:biosynthesis; D048789:Phytoestrogens; D017382:Reactive Oxygen Species / Q000032:analysis; D013481:Superoxides / Q000032:analysis
C007610:4',7-dihydroxy-3,4-dihydroisoflavone; D007529:Isoflavones; D008077:Lipoproteins, LDL; D048789:Phytoestrogens; D017382:Reactive Oxygen Species; C099252:oxidized low density lipoprotein; D013481:Superoxides; D009569:Nitric Oxide; D060754:Equol