Protective action of Ilex paraguariensis extract against free radical inactivation of paraoxonase-1 in high-density lipoprotein.

Paraoxonase 1 (PON-1), an antioxidant enzyme carried mainly by HDL, has been shown to display cardioprotective effects. In this study, we investigated whether the polyphenol-rich beverage mate, obtained from extract of Ilex paraguariensis (IP), prevented the loss of PON-1 activity from HDL during oxidant stress. The peroxide radical generator 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH) induced time- and dose-dependent oxidation of HDL, as measured by lipoperoxide content, which is accompanied by a parallel decrease in the activity of PON-1 (p<0.001). IP extract (2-20 microL/mL) afforded time- and concentration-dependent inhibition of the oxidation, with preservation of apoA-I structure and PON-1 activity. Healthy volunteers drank either 0.5 L of IP extract, 0.5 L of coffee and milk or nothing. PON-1 activity increased an average of 10% above the changes seen when the intake was coffee and milk (p<0.05). In conclusion, we demonstrate that IP extract may, to some extent, prevent the loss of the antiatherogenic function of HDL afforded by PON-1 when the particle is under oxidant stress.