Chemiluminescence determination of the in vivo and in vitro antioxidant activity of RoseOx (R) and carnosic acid

Lipid free-radical oxidation has been studied in vivo in the mitochondrial fractions of the liver of rats fed RoseOx(R) (carnosic acid nutritional sup plement) by measuring chemiluminescence. The kinetics of the lipid chemilum inescence in rats fed RoseOx(R) are significantly different from those of t he control. The intensity of the chemiluminescence fast flash decreases by 45% (p < 0.01), which indicates a reduction of lipid peroxides. The time be tween fast and slow flashes increases by 96% (p < 0.05),which indicates a h igher content of antioxidants in the lipid membrane. The in vitro experimen ts in rat liver mitochondrial fraction display more effective antioxidant a ction of alpha-tocopherol in 1 mu M concentration than 1 mu M carnosic acid by an increase of the time between fast and slow chemiluminescence flashes (p < 0.01). However, the higher antioxidant activity of 1 mu M carnosic ac id by a decrease of intensity of the chemiluminescence fast (p < 0.05) and slow (p < 0.05) flashes in comparison with alpha-tocopherol is revealed in these experimental conditions in vitro. Carnosic acid has antioxidant effec ts on homogeneous oxidation in vitro as well. The chemiluminescence of meth yl oleate initiated by 2,2'-azobis(2-methylpropionitrile) decreases by 25% (p < 0.01) in the presence of 13.5 mu M carnosic acid. 13.5 mu M alpha-toco pherol decreases the methyl oleate chemiluminescence by 45%. A higher antio xidant activity of alpha-tocopherol in comparison with carnosic acid (p < 0 .001) is found in this system. These results indicate that RoseOx(R) reduce s free-radical-induced lipid peroxidation in vivo. In vitro data show that carnosic acid has direct action as an antioxidant, rather than as a membran e-structure modifier. (C) 1999 Elsevier Science S.A. All rights reserved.