3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
P03 PROTECTIVE EFFECT OF LyCOPENE FROM
TOMATOES POwDER IN OxIDATIVE STRESS
INDuCED by ADMINISTRATION OF L-
ThyROxIN IN RATS
SAnDA AnDREI, ADELA JOAnTA, ADELA PInTEA
and M. MERCA SARLEA
University of Agricultural Sciences and Veterinary Medicine,
Faculty of Veterinary Medicine,Department of Biochemistry
3–5 Mănăştur Street, Cluj-Napoca, Romania,
sandrei@usamvcluj.ro
Introduction
Accumulating evidence has suggested that the hyperthyroidism
is associated with increases in radical oxygen
species (ROS) production and lipid peroxidation products in
some tissues of rats. The response of the antioxidant systems
is unclear. The changes in the levels of antioxidant enzymes
in various tissues were found to be imbalanced and often
opposite 1 . Lycopene, the main carotenoids in tomatos, has
been shown to be a potent antioxidant in vitro and in vivo.
Recent interest in lycopene is due to the finding of an inverse
association between dietary lycopene and risk of some types
of cancer and cardiovascular disease 2 .
There are few literature data, which present studies regarding
the effect of nonenzymatic antioxidants administration
on oxidative stress induced by thyroid hyper function. In the
present work, effects of the ingestion of tomatoes powder,
rich in lycopene, on the activities of antioxidant enzymes
(superoxid dismutase – SOD, catalase, and glutathion peroxidase),
the oxidation of lipids and on fatty acids composition
on liver, thyroid and myocardium were examined in rats
intraperitonial injected with L-thyroxin.
Experimental
E x p e r i m e n t a l P r o c e d u r e
Experiments were performed on three groups of male
white Wistar rats: control (C – nontreated animals, normal
diet); H group (treated animals with thyroxin and normal
diet) and HT group (animals treated with thyroxin and tomatoes
powder enriched diet). We induced hyperthyroidism
by intraperitoneal L-thyroxine administration, 10 µg (100 g
bodyweight) –1 , daily for a week. Daily dietary for group HT
diet was supplemented with a natural product, tomato powder,
obtained by Kunding Food Company. These powders contain
62.5 µg lycopene (1 g powder) –1 . Each rats from HT group
received 25 µg lycopene (100 g wet) –1 day –1 corresponding
to 0.4 g tomato powder (100 g wet) –1 day –1 during 7 days.
After 8 days the animals were sacrificed and thyroid, liver
and myocardium tissue were collected.
B i o c h e m i c a l D e t e r m i n a t i o n s
Protein extracts was obtained using potassium phosphate
buffer (pH = 7.35). The activities of SOD, catalase,
glutathion peroxidase and lipids oxidation were estimated in
this protein extract using photometric methods 3 .
s579
Lipids extracts from different tissues was obtained with
methanol and chloroform, based on Folch procedure The
fatty acids analysis was made on total lipids extracts using
gas-chromatography (GC) 4 .
Results
In all biological samples we can observed an increase of
antioxidant enzymes activities in H – rats compared with control.
In the case of rats treated with diet rich tomatoes powder
it can be observed a diminution of antioxidant activities probably
due the antioxidant properties of lycopene (Table I).
The increase of antioxidant enzymes activity in thyroidian
tissue could be explained due to stimulation effect of thyroid
hormones on protein shynthesis.
Table I
Antioxidant enzymes activity
Glutathone Superoxid
Tissue/ Catalase
peroxidase dismutase
Experimental ncat
groups [g wet tissue –1 U GPx U SOD
]
[g wet tissue –1 ] [g wet tissue –1 ]
Liver
C 5068.79 62.93 225.69
H 8499.99 40.30 243.61
HT 5891.08
Thyroid
61.64 206.23
C 410.10 4.66 58.87
H 793.33 7.66 83.99
HT 424.99 5.16 100.96
Myocardium
C 717.64 20.18 53.84
H 835.08 28.55 11.33
HT 690.62 23.67 95.14
Lipid peroxides levels were significantly increased compared
with control group. Oral administration of lycopene
resulted in a significant reduction of lipid peroxides levels
in HT-group compared with rats treated only with thyroxin
(Table II).
Table II
Lipids peroxides level (MDA μmoles g wet tissue –1 )
Experimental
groups
Liver Thyroid Myocardium
C 1239.44 4.98 912.11
H 1750.40 12.91 1201.92
HT 1294.74 7.96 988.24
The results of the analysis of fatty – saturated fatty acids
(SFA), monounsaturated fatty acids (MUFA) and polyunsaturated
fatty acids (PUFA) – are showed in detail by Table III.
In thyroid gland, compare with the control, we can observed
a decrease of total fatty acids content in experimental
group treated with L-thyroxin. The determination of content