Conjugated Linoleic Acid Isomers Differ in Their Free Radical Scavenging Properties

Abstract

Conjugated linoleic acid (CLA) isomers were investigated for free radical scavenging properties against the stable 2,2-diphenyl-1-picryhydrazyl radical (DPPH(*)) by electron spin resonance (ESR) spectrometry and spectrophotometric methods. ESR measurements confirmed that both c9,t11-CLA and t10,c12-CLA directly reacted with and quenched DPPH radicals, whereas spectrophotometric analysis demonstrated that c9,t11-CLA and t10,c12-CLA differed in their kinetic and thermodynamic properties in reacting with DPPH radicals. t10,c12-CLA was shown to exhibit a greater initial velocity in CLA-DPPH radical reactions at levels of 2.5-80 mg/mL, and c9,t11-CLA scavenged more DPPH radicals at steady state. Similar dose and time relationships were observed for both isomers. In addition, a mixture of c9,t11- and t10,c12-CLA isomers demonstrated a greater initial velocity in quenching DPPH radicals than either isomer alone on the same concentration basis, suggesting that a synergistic effect between CLA isomers existed in their reactions with DPPH radicals. These results support the conclusion that individual CLA isomers differ in their biological actions and indicate that interaction(s) between isomers may contribute to their beneficial effects.

Fatty Acid Composition, Antioxidant Properties, and Antiproliferative Capacity of Selected Cold‐Pressed Seed Flours

“…Fatty acid methyl esters were prepared from the hexaneextracted oils using a previously described laboratory method [9]. Fatty acid compositions were analyzed using a Shimadzu GC-2010 with a flame ionization detector and a Shimadzu AOC-20i autosampler (Shimadzu, Columbia, MD).…”

Potential Relationships Between Fatty Acid Compositions and Phytochemicals of Selected Low Linolenic Soybeans Grown in Maryland

“…The soybean oil was prepared for gas chromatography (GC) analysis according to a previously described procedure [16]. The soybean oil was saponified and methylated to form fatty acid methyl esters (FAME).…”

Identification and characterization of wild lactobacilli and pediococci from spontaneously fermented Mountain Cheese

“…Lactic acid bacteria isolated from dairy environment were found able to produce bioactive compounds, such as conjugated linoleic acid (CLA) and g-aminobutyric acid (GABA) (Settanni and Moschetti, 2010). CLA have been proposed to possess a number of putative health promoting activities (Pariza et al, 1979(Pariza et al, , 2001Ryder et al, 2001;Yang and Cook., 2003;Yu et al, 2002). GABA is produced by LAB through the decarboxylation of glutamate and since the caseins are rich in glutamate which is released by the proteolytic action, the decarboxylation of glutamate to GABA can have an important effect on the formation of eyes in cheese (Zoon and Allersma, 1996).…”