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Alexandra G. Dudnik, Natalya Yu. Lotosh, Evgeny A. Kulikov, Alexander V. Levanov, Alla A. Selishcheva
Carotenoid
astaxanthin effect on phospholipid peroxidation induced by ferrous ions
Abstract
Adstract. Activation
of the process of phospholipid peroxidation in the presence of divalent and
trivalent iron ions can cause cell death. It is generally accepted that the
addition of different types of antioxidants should lead to inhibition of this
process. The purpose of this work was to study the effect of the carotenoid
astaxanthin as an antioxidant on phospholipid peroxidation induced by iron ions
in the composition of nano- and microemulsions. It was shown that astaxanthin
itself, in the absence of iron ions, reduces the content of malondialdehyde in
micro- and nanoemulsions,
in which the particles had a size of about 700–900 nm and 110–130 nm,
respectively. However, in the presence of iron ions, in the case of
microemulsions, astaxanthin at a concentration of 30 μM reduces the content of malondialdehyde and at a concentration of 5
μM has a pro-oxidant effect. Astaxanthin and has
no effect in nanoemulsions. It was found that in the presence of iron ions,
astaxanthin becomes discolored, because undergoes degradation and oxidation. In
the case of nanoemulsions, the rate constant of the decolorization reaction was
significantly higher than in microemulsions: 18.5×103 M–1
min–1 and 2.1×103 M–1 min–1,
respectively. Thus, in the composition of nanoemulsions, astaxanthin quickly
degrades and oxidizes (within 30 min), and in the composition of microemulsions
this process is slower. Possible mechanisms of interaction of astaxanthin with iron ions are discussed, which
include both the formation of astaxanthin radicals and a non-radical complex
with iron ions. The complexation constant of astaxanthin K with iron ions was
calculated to be 2.5×105 (M–1).
Key words: astaxanthin, emulsions, ferrous, lipid peroxidation, phospholipids
Copyright (C) Chemistry Dept., Moscow State University, 2002
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