Inhibition of lipid peroxidation contributes to the attenuation of macrophage
cholesterol accumulation, foam-cell formation and
atherosclerosis. Evidence suggests that nutritional
antioxidants such as pomegranate juice (PJ) can contribute to the reduction of oxidative stress and
atherogenesis. The goals of the present study were to determine whether such beneficial effects of PJ exist when supplemented to
apolipoprotein E-deficient (E(0)) mice with advanced
atherosclerosis and to analyze the antiatherosclerotic activity of a
tannin-fraction isolated from PJ. Mice (4-mo-old) were supplemented with PJ in their
drinking water for 2 mo and compared with age-matched placebo-treated mice, as well as to young (4-mo-old) control mice, for their mouse peritoneal macrophage (MPM) oxidative state,
cholesterol flux and mice atherosclerotic lesion size. PJ supplementation reduced each of the proatherogenic variables determined in the present study compared with age-matched placebo-treated mice. It significantly induced serum
paraoxonase activity and reduced MPM
lipid peroxide content compared with placebo-treated mice and control mice. PJ administration to E(0) mice significantly reduced the oxidized (
Ox)-LDL MPM uptake by 31% and MPM
cholesterol esterification and increased macrophage
cholesterol efflux by 39% compared with age-matched, placebo-treated mice. PJ consumption reduced macrophage
Ox-LDL uptake and
cholesterol esterification to levels lower than those in 4-mo-old, unsupplemented controls. PJ supplementation to E(0) mice with advanced
atherosclerosis reduced the lesion size by 17% compared with placebo-treated mice. In a separate study, supplementation of young (2-mo-old) E(0) mice for 2 mo with a
tannin fraction isolated from PJ reduced their atherosclerotic lesion size, paralleled by reduced plasma lipid peroxidation and decreased
Ox-LDL MPM uptake. PJ supplementation to mice with advanced
atherosclerosis reduced their macrophage oxidative stress, their macrophage
cholesterol flux and even attenuated the development of
atherosclerosis. Moreover, a
tannin-fraction isolated from PJ had a significant antiatherosclerotic activity.