Physiological properties of beetroot crisps applied in standard and dyslipidaemic diets of rats

Wroblewska Monika, Juskiewicz Jerzy, Wiczkowski, Wiczkowski Wieslaw

Description

The objective of the present study was to examine the influence of adding various amounts beetroot ( Beta vulgaris ) crisps on gastrointestinal function, antioxidant status and blood and liver lipid profiles in a high fat diet-induced dyslipidaemic rat model; Results The intake of a dyslipidaemic diet increased the serum total cholesterol, total cholesterol-to-HDL-cholesterol ratio, atherogenic index, hepatic total cholesterol and triacylglycerols, suppressed production of short-chain fatty acids and decreased total antioxidant status and blood glutathione peroxidase activity. Oral administration of all tested amounts of beetroot crisps prevented the rise in serum total cholesterol and triacylglycerols levels. The treatment with the addition of 3% crisps also decreased hepatic total cholesterol level and activity of AST in serum. The experimental addition of crisps likewise resulted in a tendency towards a higher total SCFA pool and activity of glutathione peroxidase and a lower serum glucose level ( p = 0.080, p = 0.061 and p = 0.067, respectively); Conclusions Results of the presented study suggest that the addition of beetroot crisps could alleviate metabolic changes in dyslipidaemic diet-administered rats.

Sujets

• Beetroot
• RATS

Informations

• Publié par: biomed
• Publié le: 01 janvier 2011
• Nombre de lectures: 26
• Langue: English

Extrait

Wroblewska et al. Lipids in Health and Disease 2011, 10:178
http://www.lipidworld.com/content/10/1/178
RESEARCH Open Access
Physiological properties of beetroot crisps
applied in standard and dyslipidaemic diets of
rats
*Monika Wroblewska , Jerzy Juskiewicz and Wieslaw Wiczkowski
Abstract
Background: The objective of the present study was to examine the influence of adding various amounts
beetroot (Beta vulgaris) crisps on gastrointestinal function, antioxidant status and blood and liver lipid profiles in a
high fat diet-induced dyslipidaemic rat model;
Results: The intake of a dyslipidaemic diet increased the serum total cholesterol, total cholesterol-to-HDL-
cholesterol ratio, atherogenic index, hepatic total cholesterol and triacylglycerols, suppressed production of short-
chain fatty acids and decreased total antioxidant status and blood glutathione peroxidase activity. Oral
administration of all tested amounts of beetroot crisps prevented the rise in serum total cholesterol and
triacylglycerols levels. The treatment with the addition of 3% crisps also decreased hepatic total cholesterol level
and activity of AST in serum. The experimental addition of crisps likewise resulted in a tendency towards a higher
total SCFA pool and activity of glutathione peroxidase and a lower serum glucose level (p = 0.080, p = 0.061 and p
= 0.067, respectively);
Conclusions: Results of the presented study suggest that the addition of beetroot crisps could alleviate metabolic
changes in dyslipidaemic diet-administered rats.
Keywords: Beetroot, rats, dyslipidaemic diet, gastrointestinal tract, atherogenic index
Background antioxidant activity of plant pigments such as careto-
A Western diet heavy in meat, fried foods and refined noids, anthocyanins and, recently, the betalains [3,4].
grains increases the risk of developing metabolic syn- The most heavily studied betalain is betanin aglycone,
drome, heart problems, stroke and type 2 diabetes. The obtained from the extract of beet juice. Beetroot is
link between diet and chronic disease is well documen- mainly consumed as a pickled or canned preserve, a
ted. Heart disease, the main cause of death in Western cooked vegetable or sometimes a juice. In Poland, red
countries, is greatly influenced by diet, especially by the beets are popular vegetables with a per capita consump-
amount and type of fat consumed. Nutritionists recom- tion of approximately 6 kg/year. Results from several in
mend diets rich in fruits and vegetables for good health vitro studies have demonstrated that betalains from
and for reducing the risk of heart disease and some beetroots possess powerful antiradical and antioxidant
types of cancers. The beneficial effects of fruits, vegeta- activity [5-8]. In addition, a significant tumour inhibitory
bles and a Mediterranean diet are likely due to many effect has been shown to accompany a dietary treatment
components, including fibre and micronutrients [1]. The with beetroot ingestion [9]. Lammers [10] hypothesized
fundamental active agents for reducing the risk of that betanin is non-perturbing to cellular metabolism,
chronic diseases are antioxidants [2]. Over the last sev- highly compatible with enzyme function and steadies
eral years, increasing attention has been paid to the cellular metabolic function under various kinds of stress
in animal tissue. Introduction of novel products, mainly
lacto-fermented juice and crisps, has presumably con-
* Correspondence: [e-mail]
tributed to the recent growth in the intake of beetroot.Institute of Animal Reproduction and Food Research of the Polish Academy
of Sciences in Olsztyn, Poland
© 2011 Wroblewska et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.Wroblewska et al. Lipids in Health and Disease 2011, 10:178 Page 2 of 8
http://www.lipidworld.com/content/10/1/178
Some epidemiological studieshaveshownacontrary 80-80-2-2% B at gradient times, t = 0-35-36-42-43-60G
correlation between fruit/vegetable intake and the risk min. Betalains were identified based on the UV-visible
of cardiovascular disease, especially when the blood lipid spectrum, the presence of the respective ion (m/z
profile is considered [11,12]. values) and previously published data [13-15]. The mass
In this study, the hypothesis that the consumption of a spectrometer with electrospray ionization (ESI) worked
diet containing beetroot crisps could beneficially affect in the positive mode with the following parameters:
gastrointestinal function, antioxidant status of the body, CDL temperature of 260°C, CDL voltage of 70V, probe
and blood and liver lipid profiles was verified. To test voltage of 4.5 kV, nebulizer gas (N ) flow of 4.5 L/min,2
this hypothesis, different amounts of beetroot crisps and defragmentation voltage of 50 V. All determinations
were applied to a Western-type and a dyslipidaemic diet. were performed in triplicate. The use of animals was
conducted in compliance with European guidelines for
Materials and methods the care and use of laboratory animals and was
Beetroot crisps were obtained from Paula Co. (Kalisz, approved by the Ethical Committee for Animal Experi-
Poland) and contained 14.6 g of crude protein, 48.4 g of ments in the northeastern region of Poland. The experi-
carbohydrates and 0.4 g fat per 100 g of crisps. ment was performed on 64 male Wistar rats aged
The extraction, quantification and identification of approximately 4 weeks (body weight 103.8 ± 3.92 g).
betalains from beetroot crisps is described below. About The experimental diets were administered for 4 weeks
0.10 g of pulverized red beet crisps was extracted with 1 to 8 rats per group housed individually in Plexiglass
ml of distilled water by with triplicate 60-s sonication cages. The prevailing environmental temperature was
and 60-s vortexing. After centrifugation (13200 × g at 4° 21-22°C, relative humidity of 50-70% with a 12 h light-
C, 5 min), the supernatant was collected in a 5-ml flask. dark cycle and intensive ventilation of rooms (15×/h).
These steps were repeated 5 times. Quantification of The animals were allowed access to experimental diets
betalains was determined by a spectrophotometric and water ad libitum. The composition of the experi-
method according to the modified method of Stintzing mentaldietsisshowninTable1.Alldietscontained
[13]. Briefly, before analysis aliquots of red beet crisps 14.8% casein, 5% cellulose, 0.2% DL-methionine and
extract was centrifuged (8400 × g, 5 min). Next, the 0.2% vitamin-mineral mixture AIN-93G [16]. The stan-
sample was dissolved in McIlvaine buffer (pH 6.5) to dard basal diet containing 8% soybean oil and 0.3% cho-
obtain an absorbance (A) of 0.8 ≤ A ≤ 1.0. The betacya- lesterol was supplemented with different amounts of
nins and betaxanthins contents were calculated as beta- beetroot crisps: 0, 0.3, 1 or 3%. The dyslipidaemic basal
nin-equivalents and vulgaxanthin-equivalents, diet was prepared with the aid of lard instead of oil, an
respectively, using the following formula: [mg/g dry extended amount of cholesterol - 1%, and 0.5% cholic
matter] = (A*R*MW*V*1000)/ε*W, where “A” is the acid, and was supplemented with the same amounts of
absorption at 538 nm and 480 nm for betacyanins and crisps.
betaxanthins, respectively, “R” is the dilution factor, “V” At the end of the feeding experiment, the experimen-
is the volume of extract (L), “W” is the sample weight tal animals were anaesthetized with sodium pentobarbi-
(g), MW is the molecular weight (550 g/mol for betanin, tone, blood was taken from the caval tail vein, and
339 g/mol for vulgaxanthin) and “ε” is the molar extinc- serum was then obtained after clotting. The
tion coefficients (60000 L/mol*cm at l = 538 nm for
betanin, 48000 L/mol*cm at l = 480 nm for vulgax-
Table 1 Composition of experimental diets, %
anthin). Chromatographic determination of betalains
B B B B0 0.3 1 3were done on a Shimadzu HPLC system (Kyoto, Japan)
SDSDSDS Dconsisting of two pumps (LC-10AD ), a DAD detectorVP
Casein 14.8 14.8 14.8 14.8 14.8 14.8 14.8 14.8(SPD-M10 A ) set at 538 nm and 480 nm, a MS detec-VP
DL-methionine 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2tor (QP8000a), an autosampler (SIL-10 AD ) set to 10VP
Cellulose 5 5 5 5 5 5 5 5μLinjection,acolumnoven(CTO-10AS )andasys-VP
Beetroot crisps - - 0.3 0.3 1 1 3 3tem controller (SCL-10 A ). Before HPLC injection,VP
Soybean oil 8 - 8 - 8 - 8 -the extracts were centrifuged (20 min, 13200 × g). All
Lard - 8 - 8 - 8 - 8chromatographic determinations were performed at 25°
Cholic acid - 0.5 - 0.5 - 0.5 - 0.5C with the flow rate of 0.2 mL/min on C-18 BDS
Cholesterol 0.3 1 0.3 1 0.3 1 0.3 1Hypersile-Keystone 3 μ 100 × 4 mm column (Thermo,
1Mineral mix 33 333 33 3Waltham USA). The elution was done using a solvent
1Vitamin mix 22 222 22 2gradient system consisting of solvent A (0.1% formic
Maize starch 66.7 65.5 66.4 65.2 65.7 64.5 63.7 62.5acid aqueous solution) and solvent B (0.1% formic acid
1acetonitrile solution). Gradients were as follows: 2-17- According to Reeves (1997)Wroblewska et al. Lipids in Health and Disease 2011, 10:178 Page