Effect of CLAs, linoleic acid and its methyl ester on lipid peroxidation of triglycerides ω3-polyunsaturated fatty acids

FAGALI, N. S.; CATALÁ, A.

Mar del Plata

Congreso; XLIII reunión anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2007

SAIB

Conjugated linoleic acid (CLA) is a generic term used to describe a group of positional and geometric isomers of linoleic acid (LA). In CLA, two double bonds are conjugated, whereas they are methylene-interrupted in LA. Some authors showed that CLAhad antioxidative activity and proposed this as a possible explanation for the anticarcinogenic and antiatherogenic effect. However, other investigations have found that CLA was a prooxidant. The effect of CLAisomers (c9,t11 and t10,c12), LAand its methyl ester (LAME) on lipid peroxidation of triglycerides rich in C20:5 3 and C22:6 3 were analyzed by photoemission techniques. The reaction initiated by tert-butyl hydroperoxide (t-BHP) was measured at 37ºC using six different concentrations of the studied compounds. t-BHP produced an increase of chemiluminescence with a maximum at 5 min after its addition. CLAs had inhibition on photoemission being more effective the t10,c12-CLA than the c9,t11-CLA isomer. LA and LAME did not have effect on lipid peroxidation of Tg -3 PUFAs. The free radical scavenging properties of CLAs, LA and LAME were also assayed against the stable 2,2-diphenyl-1-picryhydrazyl radical (DPPH ). The reaction kinetics showed that t10,c12-CLA is more effective than c9,t11-CLA, whereas LA and LAME did not exhibit free radical scavenging properties. CLAs andLAact differently in the presence of free radicals.