Avocado Oil Supplementation Modifies Cardiovascular Risk Profile Markers in a Rat Model of Sucrose-Induced Metabolic Changes

Abstract

The purpose of this study was to evaluate the effects of avocado oil administration on biochemical markers of cardiovascular risk profile in rats with metabolic changes induced by sucrose ingestion. Twenty-five rats were divided into five groups: a control group (CG; basic diet), a sick group (MC; basic diet plus 30% sucrose solution), and three other groups (MCao, MCac, and MCas; basic diet plus 30% sucrose solution plus olive oil and avocado oil extracted by centrifugation or using solvent, resp.). Glucose, total cholesterol, triglycerides, phospholipids, low- and high-density lipoproteins (LDL, HDL), very low-density lipoprotein (VLDL), lactic dehydrogenase, creatine kinase, and high sensitivity C-reactive protein concentration were analyzed. Avocado oil reduces TG, VLDL, and LDL levels, in the LDL case significantly so, without affecting HDL levels. An effect was exhibited by avocado oil similar to olive oil, with no significant difference between avocado oil extracted either by centrifugation or solvent in myocardial injury biochemical indicators. Avocado oil decreased hs-CRP levels, indicating that inflammatory processes were partially reversed. These findings suggested that avocado oil supplementation has a positive health outcome because it reduces inflammatory events and produces positive changes in the biochemical indicators studied, related to the development of metabolic syndrome.

Full text

Research Article
Avocado Oil Supplementation Modifies Cardiovascular
Risk Profile Markers in a Rat Model of Sucrose-Induced
Metabolic Changes
Octavio Carvajal-Zarrabal,1Cirilo Nolasco-Hipolito,2
M. Guadalupe Aguilar-Uscanga,3Guadalupe Melo-Santiesteban,4
Patricia M. Hayward-Jones,1and Dulce M. Barradas-Dermitz5
1Biochemical and Nutrition Chemistry Area, University of Veracruz, SS Juan Pablo II s/n, 94294 Boca del R´
ıo, Ver., Mexico
2Department of Molecular Biology, Faculty of Resource Science and Technology, University Malaysia Sarawak,
94300 Kota Samarahan, Sarawak, Malaysia
3Food Research and Development Unit, Veracruz Institute of Technology, Calz. M.A. de Quevedo 2779, 91860 Veracruz, Ver., Mexico
4Pathology Laboratory, Institute of Forensic Medicine, University of Veracruz, SS Juan Pablo II s/n, 94294 Boca del R´
ıo, Ver., Mexico
5Biological-Chemistry Area, Veracruz Institute of Technology, Calz. M.A. de Quevedo 2779, 91860 Veracruz, Ver., Mexico
Correspondence should be addressed to Octavio Carvajal-Zarrabal; ocarvajal@uv.mx
Received  June ; Revised  December ; Accepted  December ; Published  February 
Academic Editor: Fabrizia Bamonti
Copyright ©  Octavio Carvajal-Zarrabal et al. is is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
e purpose of this study was to evaluate the eects of avocado oil administration on biochemical markers of cardiovascular risk
prole in rats with metabolic changes induced by sucrose ingestion. Twenty-ve rats were divided into ve groups: a control group
(CG; basic diet), a sick group (MC; basic diet plus % sucrose solution), and three other groups (MCao, MCac, and MCas; basic
diet plus % sucrose solution plus olive oil and avocado oil extracted by centrifugation or using solvent, resp.). Glucose, total
cholesterol, triglycerides, phospholipids, low- and high-density lipoproteins (LDL, HDL), very low-density lipoprotein (VLDL),
lactic dehydrogenase, creatine kinase, and high sensitivity C-reactive protein concentration were analyzed. Avocado oil reduces
TG, VLDL, and LDL levels, in the LDL case signicantly so, without aecting HDL levels. An eect was exhibited by avocado oil
similar to olive oil, with no signicant dierence between avocado oil extracted either by centrifugation or solvent in myocardial
injury biochemical indicators. Avocado oil decreased hs-CRP levels, indicating that inammatory processes were partially reversed.
ese ndings suggested that avocado oil supplementation has a positive health outcome because it reduces inammatory events
and produces positive changes in the biochemical indicators studied, related to the development of metabolic syndrome.
1. Introduction
Food is a factor that plays a key role in life style, a determining
inuence on health and quality of life. It is known that popula-
tions with a high consumption of meat, dairy foods, and sugar
have a higher mortality rate than those that feed mainly on
fruits, vegetables, sh, and unsaturated oils []. Undesirable
eectsonhealthareassociatedwithanexcessiveintake
of carbohydrates (sugars) and fats. Manifestations of health
disorders in people with metabolic implications are related
to the incidence and prevalence of chronic and degenerative
diseases such as obesity, diabetes, cardiovascular disease, and
dyslipidemia (low HDL-cholesterol and high triglycerides),
among others [,]. Although there are many factors that
contribute to its development, one of the main causes that
lead to these conditions is the diet that is consumed. A diet
containing a great amount of nutrients produces a strong
impact on structure, physiology, and cellular metabolism.
In recent years, the increase in these diseases has become a
global public health problem inspite of the increasing medical
knowledge for their prevention and treatment; consequently,
the nutritional aspect seems to remain vital.
Hindawi Publishing Corporation
Disease Markers
Volume 2014, Article ID 386425, 8 pages
http://dx.doi.org/10.1155/2014/386425

Disease Markers
Statistics from the Secretary of Health in Mexico indicate
that the incidence of cardiovascular diseases has increased
in recent years, so that now they are the leading cause of
death worldwide (WHO, ). On the other hand, reports
found in scientic literature about the health benets of
the Mediterranean diet and olive oil have attracted interest
in research on the eects and consumption of oils rich in
monounsaturated fatty acids, particularly oleic acid, and its
relationship with metabolic syndrome, which predisposes the
individual to more serious complications, such as diabetes
and cardiovascular diseases [–].
Mexico is a major world producer of avocados; this
fruit is a rich potential source of oil (– g/ g of fruit),
mostly monounsaturated [], and a good source of linoleic
acid []. It also contains high levels of antioxidants including
polyphenols, proanthocyanidins, tocopherols, and caroten-
oids which have shown positive health outcomes. It has also
been established that soluble components of avocado oil
confer these antioxidant properties. Studies in human and
animal models have shown that this oil helps to control
weight, reduces the risk of diabetes [], normalizes blood
cholesterol levels [], is involved in liver metabolism [], and
helpsinskincare[]. Other studies reported the presence
of functional molecules such as glutathione [], a molecule
related to decreased risk of cancer. On the other hand, the
unsaponiable components, rich in antioxidant molecules
[], have also shown benecial eects on anti-inammatory
processes related to the development of cancer [].
In the relevant literature, the benets generated by
including olive oil in the diet for cardiovascular disease risk
reduction are well documented. Due to similarities in lipid
composition between olive oil and avocado oil, it may be
assumed that the high concentration of monounsaturated
fattyacidsinavocadooilcouldbeasadequateasoliveoilfor
lowering blood lipid levels. In addition, the phytochemical
components of avocado oil are also related to the disease
manifestations associated with an altered metabolic prole;
so overall, it is expected that all the benecial properties of
avocado oil will achieve positive health eects.
2. Material and Methods
2.1. Avocado Oil Extraction. ere are dierent technologies
for extracting oil from the avocado and they can aect its
quality. e oil was obtained from Hass avocado purchased
from a local market in the Port of Veracruz, Mexico. When
edible maturity had been reached, the avocados were washed
and peeled and the seed was removed. Subsequently, the
pulp was homogenized by adding tert-butylhydroquinone
(TBHQ) at .% (w/w).
2.1.1. Oil Extraction by Centrifugation. e avocado pulp was
mixed with water to achieve a  :  w/v and NaCl (.%w/w),
the pH was adjusted to . with ascorbic acid, and the mixture
was homogenized in a blender (Black & Decker Model MX
) at , rpm for  hour at ∘C. Subsequently, the oil
was removed by centrifugation at  rpm in a tubular
continuous centrifuge (Cepa-Schnell, GLE Model NBS) fed
at . L/min.
T : Composition of basal and experimental diets formulated
according to AIN-.
Ingredients Basal diet (g)
Cornstarch .
Casein .
Cellulose .
Mineral mix AIN- .
Vitamin mix AIN- .
DL-methionine .
Tert-butylhydroquinone .
Fat†.
†Corn-canola in the basal diet (CG and MC groups); experimental diets
(MCao, MCac, and MCas resp.) were formulated with olive oil or avocado
oil, extracted either by centrifugation or solvent.
2.1.2. Avocado Oil Extraction by Solvent. Ahomogenatewas
made with a portion of the avocado pulp and two parts
of a mixture of hexane-isopropanol ( :  v/v) in separate
funnels, and the oil phase was collected. Subsequently, the
solvent was removed in a rotary evaporator (Buchi R-,
Labortechnik AG, Switzerland) at ∘C and  mmHg
pressure. e remaining solvent was removed by entrainment
with nitrogen gas and then the oil was exposed to high
vacuum in a freeze dryer for  h. ereaer the oil was stored
in refrigeration and protected from light until use.
2.2. Experimental Animals and Diets. In this experiment 
male Sprague-Dawley weaned rats ( weeks old and weighing
 ± g) were purchased from Teklad, Co. (Mexico City),
and caged individually in stainless steel boxes in a room
with controlled temperature (∘C) and a light-dark cycle
of  hours. e experimental protocol for the management
of experimental animals was approved by the animal ethics
committee, Biochemical and Nutrition Chemistry Area, Uni-
versity of Veracruz. e basal diet was prepared according
totheAmericanInstituteofNutrition[]asshownin
Table . A mixture of corn-canola oil (.g/ g diet) was
used as a source of dietary fat (Patrona from the local
market). e experimental diet was prepared based on the
composition of the basal diet plus oil (.% w/w): olive
oil (carbonell), avocado oil extracted by centrifugation or
solvent, respectively. Diets were prepared once a week and
kept in powder form at ∘C until use. As part of this study, the
fatty acid composition of the oils used in preparing diets was
analyzed and it was found that all the oils had a rather similar
composition, mainly oleic and linoleic acids (Table ).
2.3. Sucrose-Induced Metabolic Changes Model. e animals
were divided into two groups: a control group (CG, 𝑛=5)
receiving a basal diet and a group with sucrose-induced
metabolic changes (MC, 𝑛=20), which received the basal
diet plus % sucrose solution as drinking water to induce
this condition. e animals had free access to food and water
forweeksandfoodintakewasmeasureddaily.Attheend
of this period, the diet was withdrawn for at least  hours
and the manifestation of the metabolic characteristics was

Disease Markers 
T : Fatty acid composition of dietary oils (%).
Fatty acid Corn Canola Olive AvocadocAvo cad os
 :  . . . . .
 :  . . . . .
 :  . . . . .
 :  . . . . .
 :  . . . . .
 :  . . . . .
Values are expressed as mean of duplicate analysis. Avocadoc:avocadooil
extracted by centrifugation; avocados: avocado oil extracted by solvent.
checked by determining body weight; then serum glucose,
triglycerides, and cholesterol levels were determined and
obtained by cardiac puncture.
2.4. Animal Treatment
2.4.1. Experimental Diet Management. Once the sucrose-
induced metabolic changes model had been obtained, the
MC animals were divided into four groups of ve rats
each. One group was maintained on the basal diet (the
sick group, MC); three groups of rats designated, as MCao,
MCac, and MCas, respectively, received an experimental
diet containing .% w/w oil (olive and avocado extracted by
centrifugation or extracted with solvent) as the sole source
of dietary fat. ese four groups received the experimental
diets and water with % sucrose solution for  weeks. e
CG group continued to receive only the diet with corn-
canola oil and no sucrose in the drinking water. Diets were
prepared once a week and kept refrigerated until use. At
the end of the experiment the diet was withdrawn, and the
fasting animals were sacriced through decapitation. Serum
glucose, cholesterol, triglyceride, and phospholipid levels
were determined. All animals were sacriced and the organs
were extracted for further analysis.
2.5. Biochemical Indicators. All biochemical indicator anal-
yses were carried out on serum blood samples. Glucose
was determined with the glucose oxidase method. Total
cholesterol (TC), triglycerides (TG), phospholipids (PL), low-
and high-density lipoprotein (LDL, HDL), very low-density
lipoprotein (VLDL), lactic dehydrogenase (LDH), creatine
kinase (CK), and high sensitivity C-reactive protein (hs-CRP)
were determined by enzymatic colorimetric methods using
commercial kits obtained from Bayer and BioMerieux, using
an automated analyzer (RA  XT, Bayer Technicon) and a
microplate reader to determine hs-CRP. e fatty acid prole
of vegetable oils was determined by gas chromatography
(Hewlett Packard , Palo Alto, CA.) using pentadecanoic
acid as internal standard. All chemicals used were of analyti-
cal grade.
2.6. Statistical Analysis. e data are expressed as the mean ±
standard deviation (x±SD). Statistical signicance was
determined with analysis of variance procedures, with a post
hoc Tukey multiple-range test for comparison of means (𝑃<
0.05). Data were analysed using IBMcSPSScStatistics Version
, .
T : Growth parameters, food and caloric intake, liquid con-
sumption, and biochemical markers in control (CG) and sucrose-
induced metabolic changes (MC) rats.
Variabl e s Dietary groups
CG group MC group
Initial body weight (g) 239 ± 22 242 ± 24
Final body weight (g) 445 ± 53 470 ± 38∗
Body weight gain (g) 206 ± 1.8 228 ± 2.0∗
Food intake (g/d) 26.1 ± 1.3 14.3 ± 1.1∗∗
Liquid consumption (mL/d) 46.3 ± 3.3 58.1 ± 3.4∗
Liquid consumption (mL/d/ g bw) 9.3 ± 1.4 10.5 ± 0.6
kcal equivalent in drinking water . 10.8 ± 1.7∗∗
Glucose (mg/dL) 114 ± 18 130 ± 11
Cholesterol (mg/dL) 104 ± 12 101 ± 12
Triglycerides (mg/dL) 79 ± 12 179 ± 35∗∗
Valu e s a re mea n ±SD. CG group: 𝑛=5;MCgroup:𝑛=20.∗𝑃 < 0.05;
∗∗𝑃 < 0.01.
3. Results
3.1. Metabolic Characteristics Evaluating Rats in the Control
Group and Rats with Sucrose-Induced Metabolic Changes.
Table  shows growth variables, food and caloric intake,
liquid consumption and the biochemical markers assessed
in rats of the control group (CG) and those with sucrose-
induced metabolic changes (MC).
Aer  weeks, a signicant increase (𝑃 < 0.05)in
nal body weight and body weight gain was observed in
the MC group as compared to the CG group, although the
food intake in rats in the CG group was signicantly higher
(𝑃 < 0.01) than in the MC group. Contrary to this, the MC
group showed a daily liquid intake signicantly higher (𝑃<
0.05) as compared with the CG group. However, when the
daily liquid intake per  g in weight was compared between
CG and MC groups, this was not signicant. e caloric
equivalent produced by liquid intake was . ±. kcal in
the MC group; the CG group did not have any energy intake,
because this group received only puried drinking water.
Triglyceride levels in the MC group were signicantly greater
(𝑃 < 0.01)thanintheCGgroup;however,nosignicantly
dierent results were found in any group for either glucose or
cholesterol levels.
3.2. Eect of Dietary Oils on Metabolic Change Biochemical
Indicators. e eect of olive and avocado oils on biochem-
ical indicators in rats with metabolic changes induced by
sucrose ingestion aer the administration of experimental
diets for  weeks is shown in Tab l e  .
MC group triglyceride levels increased signicantly (𝑃<
0.05),atleast.timeswithrespecttotheCGgroup.On
the contrary, MCao, MCac, and MCas groups exhibited
reduced levels, although not signicant compared to MC
andnotreachingthelowerCGlevels.Asforphospholipids,
the MC group showed signicantly increased levels (𝑃<
0.05) compared to CG; however, in MCao, MCac, and MCas
groups, no signicant change was observed when compared
to MC, but their results were signicantly higher (𝑃 < 0.05)

Disease Markers
T : Glucose- and lipid-metabolic parameters 𝑥±SD (mg/dL) in rats fed diets with dierent dietary oil sources during  weeks.
Variabl e s Dietary groups
CG MC MCao MCac MCas
Glucose 147 ± 41 158 ± 18 155 ± 38 145 ± 16 131 ± 21
Triglycerides 48 ± 11 181 ± 29∗145 ± 42∗145 ± 58∗133 ± 28∗
Cholesterol 95 ± 12 91 ± 9 97 ± 11 99 ± 12 104 ± 14
Phospholipids 43 ± 4 55 ± 4∗57 ± 4∗56 ± 4∗55 ± 6∗
HDL-C 18 ± 4 18 ± 3 19 ± 3 18 ± 4 20 ± 4
LDL-C 50 ± 1 69 ± 1∗∗ 50 ± 2 51 ± 1 53 ± 1∗
VLDL 10 ± 2 36 ± 6∗30 ± 10∗29 ± 11∗28 ± 6∗
Valu e s a re mea n ±SD.
Corn-canola diet (CG group, 𝑛=5); MC group: corn-canola diet plus % sucrose in drinking water (𝑛=5); MCao group: olive oil plus % sucrose in
drinking water (𝑛=5); MCac group: avocado oil extracted by centrifugation plus % sucrose in drinking water (𝑛=5); MCas group: avocado oil extracted
by solvent plus % sucrose in drinking water (𝑛=5).
∗𝑃<0.05;∗∗𝑃<0.01compared to corresponding data in CG group.
T : Prole of myocardial injury enzymes in rats fed diets with dierent dietary oil sources during  weeks.
Variabl e s Dietary groups
CG MC MCao MCac MCas
Lactic dehydrogenase (U/L) 3820 ± 955 3446 ± 1214 2974 ± 2145 802 ± 598 3573 ± 1031
Creatine kinase (U/L) 822 ± 198 556 ± 71 364 ± 220 530 ± 358 658 ± 254
High sensitivity C-reactive protein (mg/dL) 1.7 ± 0.1 3.0 ± 0.2∗∗ 1.8 ± 0.2∗1.5 ± 0.1 1.5 ± 0.1
Valu e s a re mea n ±SD.
Corn-canola diet (CG group, 𝑛=5); corn-canola diet plus % sucrose in drinking water (MC group, 𝑛=5); olive oil diet plus % sucrose in drinking water
(MCao group, 𝑛=5); avocado oil diet extracted by centrifugation plus % sucrose in drinking water (MCac group, 𝑛=5); avocado oil diet extracted by
solvent plus % sucrose in drinking water (MCas group, 𝑛=5).
∗𝑃<0.05;∗∗𝑃<0.01versus corresponding data in CG group.
when compared to CG. LDL levels in MCao and MC ac groups
did not show signicant dierences with respect to CG, but
there was a very signicant increase (𝑃 < 0.01)intheMC
group, much more than the increase (𝑃 < 0.05)inthe
MCas group. VLDL in the MC group increased . times in
comparison to CG levels and no signicant decrease from
there was observed in MCao, MCac, and MCas groups, all
still signicantly higher (𝑃 < 0.05)thanCG.Signicantly
dierent results were not found for any group in the cases of
glucose, cholesterol, or high-density lipoproteins (HDL).
3.3. Eect of Dietary Oils on Myocardial Injury Indicators. e
eectofdietaryoliveandavocadooilsonmyocardialinjury
indicators in rats with metabolic changes induced by sucrose
ingestion is shown in Tab l e  .
A highly signicant increase (𝑃 < 0.01) of hs-CRP serum
levels was observed in the MC group, almost double CG
values.eMCaogroupmanagedtorevertthechangein
these levels somewhat (𝑃 < 0.05), while MCac and MCas
groups completely returned to CG values. Lactic dehydroge-
nase (LDH) and creatine kinase (CK) levels did not show any
signicant dierences for any study group compared to CG;
however, in MCao, MCac, and MCas groups, CK levels did
fall below CG values.
4. Discussion
Metabolic changes are associated with a number of diseases,
including obesity, diabetes, hypertension, dyslipidemia, and
other abnormalities of importance related to their develop-
ment. ese are grouped into dierent proles, such as liver,
pancreatic, and cardiovascular functions.
Within this framework, in the present study, signicant
dierences were found for MC groups as compared to the
CGgroupinnalbodyweightandweightgain,whichwere
signicantly higher ( and %, resp.), although food intake
was signicantly lower (%). ese results are consistent
with those reported in other studies where metabolic changes
were induced by the administration of a sucrose-rich diet
in addition to an experimental diet causing changes in the
biochemical indicators measured [,]. In relation to serum
biochemical indicators associated with the development of
metabolicabnormality,itwasfoundthatglucoseandcholes-
terol concentrations in MC group rats were similar to those
intheCGgroupandnotsignicant.ReavenandChang[]
have suggested that this is due to hyperinsulinemia developed
in metabolic abnormalities which maintains normal levels
of blood glucose. TG levels were signicantly higher (%)
in MC group rats (a . fold increase). Other studies have
found similar results [,]; Piatti et al. []reportedthe
association in healthy patients between sudden TG elevation
and insulin resistance and suggested that the increase in
blood TG in vivo inhibits glucose utilization and oxidation
stimulated by insulin action in the peripheral tissues. One
waytoexplainbloodTGelevationmightbetoconsidera
possible increase in the reesterication of fatty acids from the
liverasaresultoffructosemetabolism,asreportedbyBezerra
et al. []; this monosaccharide stems from sucrose hydrolysis

Disease Markers 
and in the liver, fatty acids are mainly used for the HDL and
TG synthesis, which in turn raise serum levels.
Few studies have evaluated the inuence of avocado
oil as a dietary fat on the lipid prole and lipoprotein
metabolism, specically in animal models with manifesta-
tions of metabolic disorders. is study found that the dietary
intake of olive oil and avocado oil extracted by centrifugation
or solvent exerted little or no eect on glucose, cholesterol,
and HDL levels, there being no signicant changes in the
circulating levels of these indicators for any study group.
Among the most important eects observed in this
experiment is the signicant elevation of TG levels in the
MC group, at least .-fold compared with the CG group, a
phenomenon reversed with the subsequent administration of
olive oil or avocado extracted by centrifugation or solvent.
is eect is attributed to the ingestion of a high amount
ofsucroseinthedrinkingwaterandisafeatureofthe
metabolic disorder [], since several studies demonstrate
that high carbohydrate intake is associated with increased
TG levels []. On the other hand, the MCao, MCac, and
MCas groups were able to reduce TG levels signicantly (,
,and%,resp.)comparedtotheMCgroup,although
without reaching the lower levels of the CG group. ese
data are consistent with previous ndings by Lerman-Garber
et al. [], Carranza et al. [], and L´
opez Ledesma et al.
[],whoshowedthatadietsupplementedwithavocadooil
fordaysindiabeticsubjectswithinduceddyslipidemia
decreased TG levels by , ., and .%, respectively.
In addition, the observations reported in this study add
support to those postulated by P´
oveda et al. [], which
indicate that oils rich in monounsaturated fatty acids and
micronutrientsmayhelplowerTGlevelsandreducethe
unfavorableresponseinthelipidproleobservedwith
saturated fatty acids. Phospholipids maintained a similar
percentage increase (, , and %) in the MCao, MCas, and
MCac groups, with respect to the SG group, and showed no
signicant eect on this indicator; however, their levels were
all signicantly higher, by , , and %, respectively, in
relation to the CG group. Other researchers have reported
that, although olive oil has a hypocholesterolemic eect on
theserumlipidprole[], there is some evidence to suggest
that it does not signicantly aect the prole of heart or
erythrocyte phospholipids []. On the other hand, it has
been found that avocado oil supplementation in rats increases
thephospholipidfractioninHDLasasurfacecomponent
[]; the present study shows that avocado oil, while being
a crude oil high in micronutrients, also has a signicant
percentage of monounsaturated fatty acids (:N oleic: –
%), which could explain its eect to increase phospholipid
levels.
It has been established that the consumption of olive oil
reduces cholesterol bound to LDL (LDL-C) when replacing
a source of saturated fat or one high in carbohydrates [,
].iseecthasbeendemonstratedwithoilsrichin
monounsaturated fatty acids; however, it is not exclusive to
oliveoilandisalsoproducedbyotheroilsrichinoleicacid,
such as avocado oil. is study conrmed that olive oil very
signicantly decreased (%) LDL levels in the MCao group
and that avocado oil extracted by centrifugation (MCac) or
solvent (MCas) reduced very signicantly and signicantly
theselevels,byand%,respectively,comparedwithMC
group levels.
Itiswellknownthatamongtherelevantmechanismsof
atherosclerosis pathogenesis are the oxidation of low-density
lipoproteins (LDL) in the artery walls, the proliferation of
smooth muscle cells, endothelial activation, and leucocyte
xation.
Among the studies linked to these mechanisms and to
thepresenceofoleicacidarethosewhichrelatethetypeof
fattyacidpresentintheoilsconsumedtoLDLsusceptibility
to oxidation. Parthasarathy et al. [] demonstrated that LDL
particles rich in oleic acid are markedly more resistant to
oxidative changes. is has been corroborated by Abbey et
al. [] and Reaven et al. []wherethissameparticletype
presented greater resistance to ex vitro oxidation than those
rich in linoleic acid. Moreover, Mata et al. []reportedthat
supplementation with monounsaturated fatty acids produces
a reduction in the synthesis of smooth muscle cells in
cell cultivations incubated with human serum. Studies with
endothelial cells showed that oleic acid inhibits endothelial
activation analysed through VCAM- expression (vascular
cell adhesion molecule-) []. Carluccio et al. []suggested
that oleic acid contributes to atherosclerosis prevention by
replacing the saturated fatty acids of cell membrane phospho-
lipids and by modulating the genetic expression of molecules
implicated in monocyte capture.
Basedonalltheabove,itispossibletolinktheoleicacid
present in both olive and avocado oils used in this study to
the variety of mechanisms mentioned.
On the other hand, it is possible that part of the
hypocholesterolemic eect observed is due to changes in the
metabolism of LDL lipoproteins caused by the ingestion of
avocado oil in the diet, an eect related on the one hand
to the type of fat and, on the other, to the concentration
of biologically active microcomponents acting additively or
synergistically and not simply as isolated components [].
Experimental data indicate that polyphenols from virgin
and extra virgin oils might additionally inuence lipid
metabolism,thusreducingHMG-CoAreductaseactivityand
modifying lipid values [].
e intake of olive oil (MCao) and avocado oil extracted
by centrifugation (MCac) or solvent (MCas) signicantly
decreased (, , and %, resp.) the VLDL levels when
comparedtotheSGgroup.Ontheotherhand,supplementing
a diet with avocado oil not only lowers LDL but also TG
associated with VLDL. As it appears, in comparison with
oliveoil,thecrudeavocadooilcomponentsmaybethecause
of this metabolic eect in the liver, reducing triglyceride-
rich lipoproteins biosynthesis. ese observations have been
conrmed in previous studies [,].
Metabolic changes did not aect LDH levels; although
thelevelsofthisenzymedecreased(.%)intheMCgroup,
their values were not signicantly dierent compared to
those in the CG group. In the olive oil group (MCao),
LDH levels were reduced by % ( versus  U/L),
whereas in the avocado oil groups extracted by centrifugation
(MCac) or solvent (MCas), LDH levels decreased by %
and increased by %, respectively, compared with the MC

Disease Markers
group. Moreover, in all groups, the olive oil (MCao) and
avocado oil extracted by centrifugation (MCac) or solvent
(MCas) groups, LDH levels decreased by , , and .%,
respectively,incomparisonwithCGgroup,butnosignicant
eect was observed because the values of this indicator
overlapped with those in the CG group (, , and 
versus  U/L, resp.).
Regarding CK, it was observed that the metabolic abnor-
mality did not signicantly aect its levels. e SG group had
decreased CK levels (%) as compared to the CG group;
the olive oil group (MCao) exhibited decreased enzyme levels
wellbelowthoseintheCGandMCgroups(and%,resp.)
and a decrease of  and %, respectively, when compared to
MCac and MCas data. It should be noted that although both
olive oil and avocado oil groups had decreased CK levels, no
signicant eect was observed when compared with MC and
CG groups.
Serumlevelsofhs-CRPintheMCgroupshowedavery
signicant increase (. times) compared to the CG group.
is is consistent with other studies in humans, since it has
been reported that hs-CRP levels are increased in subjects
with signs of health disorders from metabolic abnormality
[]; this increase may also heighten the risk of cardiovas-
cular disease []. Nevertheless, the olive oil group (MCao)
reversed hs-CRP levels, almost reaching CG group levels (.
versus.U/L)butstillwitha.%signicantdierence.
Meanwhile, avocado oil extracted by centrifugation (MCac)
or solvent (MCas) groups reduced hs-CRP levels even more
than olive oil so as to attain levels statistically similar to
the CG group (. and . versus . mg/dL, resp.). As can
beobserved,botholiveoilandavocadooilextractedby
centrifugation or solvent reversed the metabolic changes
induced by sucrose ingestion signicantly and very signi-
cantly reducing hs-CRP levels by % in the MCao group
and by % in the MCac and MCas groups, respectively, as
compared with the MC group. It has been shown that oils rich
in monounsaturated fatty acids do not increase hs-CRP levels
[];instead,theseareloweredinsubjectswhoconsume
a Mediterranean diet, where the main source of monoun-
saturated fatty acids is olive oil []. Other studies show
that elevated hs-CRP levels are directly related to infectious
processes, inammatory response, steatosis, cardiovascular
disease, prevalence, and risk of arteriosclerotic ventricular
thrombosis [,–]; this is why the use of hs-CRP has
been proposed in prognostic stratication in subjects having
health disorders with metabolic abnormalities [].
e inammatory response and its relationship with
atherosclerosis-cardiovascular risk is well demonstrated;
however, it is still under discussion if the measurement
of increased levels of hs-CRP consistently and signicantly
predict cardiovascular risk from a clinical point of view [].
In the present case, one possible explanation of a decrease
in hs-CRP (an inammation biomarker) in a diet with olive
or avocado oil (obtained by any method) could be related to
cytokine inhibition observed in diets with a high oleic acid
content [], considering that interleukin  sets o hepatocyte
hs-CRP synthesis [].
To the best of our knowledge, these markers have not been
evaluated in rat models where metabolic changes induced by
sucroseingestionareassociatedwithliverdamagecausedby
abnormalities in liver function. A concentration of normally
metabolized molecules occurs which can have a detrimental
eect on health, hence the importance of these ndings in the
study of the eect of dietary oils such as from avocados.
In conclusion, the results suggest that avocado oil and its
antioxidant content place it as a potential oil to be used as
one of the preventive factors of metabolic syndrome since
it reduces TG, LDL, and VLDL levels, signicantly so in
the case of LDL, without aecting HDL levels. Furthermore
the results indicate that avocado oil exerts eects similar to
olive oil, and that the type of extraction exerts an eect on
only one of the biochemical indicators analyzed. It has also
been found that avocado oil extracted by centrifugation or
solvent decreases hs-CRP levels, indicating that inamma-
tory processes have been at least partially reversed, probably
because the manifestation time of metabolic change was very
short. Further studies are needed to elucidate the eects on
cardiovascular risk prole and inammatory markers and
establish the optimal time of avocado oil supplementation
in rats with sucrose-induced metabolic changes, as well as
the :N specic action on human phospholipid fraction
biosynthesis in HDL as a surface component.
Conflict of Interests
e authors certify that they do not have any conict of
interests regarding the publication of this paper.
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