Introduction
Lipid peroxidation has been established as a major mechanism of cellular
injury in many biological systems of plant and animal origin. The mechanism
involves a process whereby unsaturated lipids are oxidized to form additional
radical species as well as toxic by-products that can be harmful to the host
system. Polyunsaturated lipids are especially susceptible to this type of
damage when in an oxidizing environment and they can react to form lipid
peroxides. Lipid peroxides are themselves unstable, and undergo aditional
decomposition to form a complex series of compounds including reactive
carbonyl compounds. Polyunsaturated fatty acid peroxides
further react to form malonaldehyde (MDA).
MDA can be found in most biological samples including foodstuffs, serum, plasma,
tissues and urine, as a result of lipid peroxidation, and has become one of the
most widely reported analytes for the purpose of estimating oxidative stress effects on lipids.
Method:
The NWLSS™ NWK-MDA01 assay is based on the reaction of malondialdehyde (MDA)
with thiobarbituric acid (TBA); forming a MDA-TBA2 adduct that absorbs
strongly at 532 nm.
This reaction is the most popular method for estimating MDA in biological
samples. However, interference can be a significant problem in some biological
samples if not dealt with appropriately.
Method Improvements:
The NWLSS™ method minimizes Ex vivo lipid peroxidation and maximizes recovery
of MDA by carefully optimizing the reaction conditions.
- BHT and EDTA are added to
the sample and reaction mixture to minimize
artifact oxidation.
- Reaction temperature has
also been reduced to minimize the decomposition of
lipid hydroperoxides.
- Reaction pH has been
optimized to facilitate hydrolysis of MDA-protein
adducts for better recovery of MDA.
- Cleaner output through optimized data reduction
using single wavelength ABS532 or 3rd derivative SCAN400-700 analysis.
