1063-0740/05/3105- © 2005 Pleiades Publishing, Inc.
Russian Journal of Marine Biology, Vol. 31, No. 5, 2005, pp. 331–334.
Original Russian Text Copyright © 2005 by Biologiya Morya, Kolenchenko, Sonina, Khotimchenko.
The problems of chemical regulation of oxidizing
stress and the search for biologically active substances
with antioxidant activity are the focus of attention of
researchers in different ﬁelds of experimental biology
and biomedicine [11, 15, 16]. In physiological condi-
tions, the oxidation–reduction processes, which cover
the energy need of cells and support oxygen utilization
in tissues, are controlled by regulatory systems main-
taining balanced interactions between the reactions that
generate the products of oxidation and antioxidizing
factors. Disturbances in this interaction, accompanied
with activation of free radical processes and accumula-
tion of products of lipid peroxidation, are considered as
a universal mechanism of biological membrane dam-
age [10, 20] that is the basis of some pathological pro-
cesses [9, 12].
Investigations of the relations between oxidizing
stress and the development of many diseases revealed
that the endogenous antioxidative system does not pro-
vide sufﬁcient protection for cells and tissues against
the damaging effects of free radicals. Therefore, the
search for new agents of inhibition of prooxidative pro-
cesses and the activation of antioxidation reactions is
rather warranted [8, 21].
Among numerous natural compounds of high bio-
logical activity, zosterin polysaccharide, which was
named after the source if its isolation, the eelgrass
, a member of the family Zosteracea,
has attracted particular attention. Zosterin is a pectin
with an extremely low degree of etheriﬁcation .
Experimental studies on zosterin pectin have revealed
its pharmacological effects, such as the hypocholester-
emic, entherosorption, antibacterial, antiviral, antitu-
moral, antiulcer, and immunomodulating effects .
Some of these effects are accompanied by a decrease in
the concentration of the products of lipid peroxidation
and normalization of the parameters of the endogenous
antioxidative system in the blood and liver of experi-
mental animals [3, 5]. These data presume the available
antioxidative effects of the studied polysaccharide.
The objective of this study was to reveal the antiox-
idative activities of low-etheriﬁed pectin from the eel-
and compare its activities with those of
drugs used in medicine as antioxidants.
MATERIAL AND METHODS
was sampled from
clean water areas of Peter the Great Bay, Sea of Japan.
The pectin was isolated using techniques that included
acid hydrolysis of raw material, extraction with ammo-
nium oxalate, and sedimentation of pectin with ethanol
. The content of galacturonic acid in the pectin was
determined applying the colorimetric hydroxydiphenyl
method . The etheriﬁcation was determined by the
titrimetric technique . The characteristic viscosity
was determined in a mixed solution of 0.05 M sodium
chloride and 0.005 M sodium oxalate at a temperature
C and pH of 6.0 with an Ubbelohde viscosime-
ter . The physical and chemical parameters of the
isolated polysaccharide assay were as follows: galactu-
ronic acid content, 70.0%; etheriﬁcation, 7.9%; and
characteristic viscosity, 620 ml/g of galacturonane.
Assessment of Antioxidant Activities
of Low-Etherified Pectin from the Eelgrass
and Antioxidative Medicines
E. A. Kolenchenko
, L. N. Sonina
, Yu. S. Khotimchenko
Institute of Marine Biology, Far East Division, Russian Academy of Sciences, Vladivostok 690041
Vladivostok State Medical University, Vladivostok 690990
Received May 4, 2005
—A comparative study of antioxidant activities of low-etheriﬁed pectin extracted from the eelgrass
and of two antioxidative medicines, mildronat and emoxipin, was carried out using two
methods allowing us to estimate the reducing activities of the compounds (FRAP assay), and their ability to
impede iron- and ascorbate-induced oxidation of Tween 80 to malondialdehyde. It was found that zosterin pec-
tin manifested higher reducing activity compared to the medicines. The inhibitory capacity of zosterin was
lower than that of mildronat.
antioxidants, antioxidant activity, pectin, zosterin,
, FRAP assay.