Effect of antioxidant protection by p-coumaric acid on low-density lipoprotein cholesterol oxidation.
Mechanisms in which p-coumaric acid (CA) acts as an antioxidant are not well understood. This study investigated whether CA can act as a direct scavenger of reactive oxygen species (ROS) and whether it minimizes the oxidation of low-density lipoprotein (LDL). Rats were administered CA in drinking water at low or high doses for 10, 21, and 30 days (uptakes were 29 and 317 mg/day, respectively). Blood levels of 8-epiprostaglandin F(2alpha) were monitored as a marker of LDL oxidation. Oral administration of CA (317 mg/day) for 30 days significantly inhibited LDL oxidation. CA also reduced LDL cholesterol levels in serum but had no effect on levels of high-density lipoprotein cholesterol. In vitro studies that used electron spin resonance in combination with spin trapping techniques were used to determine the ability of CA to scavenge ROS and alter LDL oxidation. CA effectively scavenged.OH in a dose-dependent manner. IC(50) and maximum velocity for CA scavenging of.OH were 4. 72 microM and 1.2 microM/s, respectively, with a rate constant of 1. 8 x 10(11) M(-1). s(-1). Our studies suggest that the antioxidant properties of CA may involve the direct scavenging of ROS such as.OH.
Zang
L Y
LY
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505-2888, USA.
Cosma
G
G
Gardner
H
H
Shi
X
X
Castranova
V
V
Vallyathan
V
V
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000187:drug effects* / Q000378:metabolism*; D003373:Coumaric Acids / Q000737:chemistry / Q000494:pharmacology*; D003497:Cyclic N-Oxides / Q000032:analysis / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000737:chemistry; D008297:Male; D010084:Oxidation-Reduction / Q000187:drug effects; D011422:Propionates; D051381:Rats; D017207:Rats, Sprague-Dawley; D013113:Spin Labels
D000975:Antioxidants; D008078:Cholesterol, LDL; D003373:Coumaric Acids; D003497:Cyclic N-Oxides; C045076:Fenton's reagent; D016166:Free Radical Scavengers; D011422:Propionates; D013113:Spin Labels; D017665:Hydroxyl Radical; C069977:2,2-dimethyl-5-hydroxy-1-pyrrolidinyloxy; D002784:Cholesterol; D006861:Hydrogen Peroxide; D007501:Iron; C495469:p-coumaric acid