Research Communications
Availability and antiperoxidative
effects of -carotene from Dunaliella
bardawil in alcohol-drinking rats
Moshe J. Werman, Ami Ben-Amotz, and Shoshana Mokady
Department of Food Engineering and Biotechnology, Technion; and The National Institute of
Oceanography, Haifa, Israel
The present study demonstrated the high bioavailability and antiperoxidative capacity of the natural -carotene
isomer mixture of Dunaliella bardawil compared with synthetic -carotene under alcohol-induced oxidative
stress. Weanling rats were adapted to ethanol by increasing ethanol levels in their drinking water to 30% at 5%
intervals per week; other rats received water with no added ethanol. One water-drinking group and one
alcohol-drinking group with no dietary carotene were used as controls. Two water-drinking groups were
supplemented with 1 g/kg diet -carotene either from Dunaliella or a synthetic source, and due to reduced food
intake, two ethanol-fed groups received 2 g -carotene per kilogram of diet from each source. Following 3
months of ethanol consumption, both carotene sources were found to prevent ethanol-induced lipid peroxidation
as expressed by the hepatic conjugated oxidized dienes level. However, in the algal-fed rats, hepatic carotene and
vitamin A levels were higher. In addition to a lower performance of the group fed ethanol and synthetic
-carotene, there were three deaths in this group. (J. Nutr. Biochem. 10:449–454, 1999) © Elsevier Science
Inc. 1999. All rights reserved.
Keywords: Dunaliella bardawil; -carotene; alcohol; lipid peroxidation; vitamin A; rats
Introduction
In recent years the consumption of foods rich in -carotene
has been shown to be associated with reduced risk of several
pathologic events. Thus, a large number of epidemiologic
and controlled studies have indicated the role of dietary
-carotene in the prevention of certain types of cancer.
1
In
addition, Gey et al.
2
demonstrated an inverse relationship
between -carotene intake or plasma level and the risk of
cardiovascular disease. The properties of -carotene as a
potent free radical quencher, singlet oxygen scavenger, and
antioxidant—not its activity as provitamin A—have been
implicated as paramount in this protective role.
3
Chronic alcohol consumption, which is known to be
responsible for the generation of free radicals,
4
results in
liver injury accompanied by decreased hepatic vitamin A
content in rats, baboons, and humans.
5,6
Therefore, supple-
mentation of -carotene as a vitamin A precursor as well as
an antioxidant was recommended. However, recent studies
using alcohol-fed baboons
7
and rats
8
demonstrated that
supplementing synthetic -carotene in the diets of these
animals resulted in histologic changes in the liver and
potentiation of the hepatotoxicity of alcohol. Furthermore,
Ahmed et al.
9
suggested that dietary fortification with
synthetic -carotene during active drinking in humans
might lead to hepatotoxic alcohol–-carotene interactions.
Recently, two human intervention studies noted the
possible carcinogenicity of the synthetic all-trans -caro-
tene.
10,11
Therefore, attention was drawn to -carotene from
natural sources, such as that found in fruits and vegetables,
which also contain small amounts of other -carotene
isomers.
12
The unicellular algae Dunaliella bardawil has received
much attention in recent years as a natural rich source of
-carotene, due to its ability to accumulate large amounts of
Address correspondence to Dr. Moshe J. Werman, Department of Food
Engineering and Biotechnology, Technion, Haifa, 32000, Israel.
Received November 18, 1998; accepted April 13, 1999.
J. Nutr. Biochem. 10:449–454, 1999
© Elsevier Science Inc. 1999. All rights reserved. 0955-2863/99/$–see front matter
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