http://sgpwe.izt.uam.mx/files/users/uami/jaislocr/QUIMICA_DE_ALIMENTOS/oxidacion_de_lipidos_y_consecuencia.pdf

Routes of formation and toxic consequences of lipid oxidation products in foods.

The biological significance of malondialdehyde determination in the assessment of tissue oxidative stress.

Noninvasive measures of oxidative stress status in humans.

Lipid peroxidation in turbot (Scophthalmus maximus) tissue: effect of dietary vitamin E and dietary n-6 or n-3 polyunsaturated fatty acids

Rats were fed for 5 wk 10% (wt/wt) menhaden oil (MO) or a 10% corn oil-lard (COL) mixture (1:1) in diets with a low vitamin E content (less than or equal to 5 mg/kg) or supplemented with d-alpha-tocopheryl succinate to a total of 30 or 150 mg per kg. Thiobarbituric acid-reactive substances (TBARS), conjugated dienes (CD), hexanal and total volatiles (TOV) were measured in tissue homogenates incubated at 37 degrees C for 1 h in the absence (uninduced) and presence of 15 microM ferrous sulfate (induced). The fatty acid composition of liver and kidney reflected that of dietary lipids. For uninduced peroxidation, there was in general a significant inverse correlation of TBARS, CD and TOV with the log of dietary vitamin E content for liver and kidney from rats fed either lipid. For induced peroxidation, the inverse correlation was significant for liver, but not for kidney, from rats fed either lipid. The correlation was generally higher for liver and kidney from rats fed COL than for tissues from rats fed MO. Vitamin E was thus a more effective antioxidant for liver than for kidney regardless of the dietary lipid, and for liver and kidney from rats fed COL than from rats fed MO. Dietary MO enhanced tissue susceptibility to both peroxidation systems. A simulation model developed to mimic the experiments showed good correlations between experimental data and simulated values.

Effect of dietary lipids and vitamin E on in vitro lipid peroxidation in rat liver and kidney homogenates.

Urinary malondialdehyde (MDA), an indicator of lipid peroxidation in the diat and in the tissues, was determined in human adults consuming a supplement of n-3 fatty acids derived from a pharmaceutical grade of cod liver oil (CLO) without added antioxidants vs a concentrate of n-3 acids containing dodecyl gallate and vitamin E. MDA excretion increased immediately in the subjects consuming CLO but remained unchanged in those ingesting the concentrate for 50 days. The increase in the subjects taking CLO was attributable to MDA in the oil. The results indicate that consuming unstabilized fish oils as a source of n-3 fatty acids may entail exposure to potentially toxic products of lipid peroxidation.

P. D. Cole

Papers

Malondialdehyde excretion by subjects consuming cod liver oil vs a concentrate of n-3 fatty acids.