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Journal of Medicinal Plants Research Vol. 5(19), pp. 4918-4924, 23 September, 2011
Available online at http://www.academicjournals.org/JMPR
ISSN 1996-0875 ©2011 Academic Journals
Full Length Research Paper
Lipid-lowering effect of artichoke on liver
phosphatidate phosphohydrolase and plasma lipids in
hyperlipidemic rats
Esfandiar Heidarian1*, Effat Jafari-Dehkordi2 and Ali Seidkhani-Nahal3
1Clinical Biochemistry Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran.
2Traditional Medicine Department, Tehran University of Medical Sciences, Tehran, Iran.
3Biochemistry Department, Ilam University of Medical Sciences, Ilam, Iran.
Accepted 19 July, 2011
Artichoke (Cynara scolymus L.) is full of natural antioxidants and has a lipid-lowering effect. The aim of
this study was to investigate the effect of artichoke on the liver phosphatidate phosphohydrolase
(PAP), plasma lipid levels, plasma malondialdehyde (MDA), and plasma antioxidant in hyperlipidemic
rats. Male rats were fed by standard pellet diet (Group 1), standard diet supplemented with 10%
artichoke (Group 2), lipogenic diet (containing sunflower oil, cholesterol and ethanol) plus 10%
artichoke (Group 3) and only lipogenic diet (Group 4). On day 60 of the experiment, liver PAP activity,
liver triglyceride (TG), plasma lipids, plasma MDA, and plasma antioxidant levels were measured. PAP
activity, liver TG, the ratio of total cholesterol (TC) to high density lipoprotein (HDL) cholesterol, plasma
TC and TG levels were significantly decreased due to artichoke treatment in Groups 2 and 3 compared
to Groups 1 and 4, respectively. Significant reduction in plasma MDA and significant elevation in
plasma antioxidant power observed in Groups 2 and 3 compared to Groups 1 and 4, respectively. The
results clearly indicated that artichoke can be useful for the reduction of PAP activity and liver TG. Also,
artichoke has beneficial effects in the controlling of hyperlipidemia, abnormalities in lipid profiles and
oxidative stress in hyperlipidemic regimes.
Key words: Artichoke, hyperlipidemia, liver triglyceride, plasma lipids, phosphatidate phosphohydrolase.
INTRODUCTION
Alterations in serum lipid and lipoprotein levels, especially
hypercholesterolemia, result in a variety of chronic
diseases such as coronary heart diseases and athero-
sclerosis (Gould et al., 2007; Laker, 2006; McKenney,
2001). Many studies have been conducted on plant
flavonoids that might be beneficial in reducing the risk of
obesity and its complications (Andersen et al., 2010;
Mulvihill and Huff, 2010). In this respect, artichoke
(Cynara scolymus L.) is introduced as new lipid-lowering
therapeutic agent (Joy and Haber, 2007; Küskü-Kiraz et
al., 2010). Artichoke leaves were used in traditional
medicine for a variety of diseases especially, hyper-
lipidemia. Hypolipidemic effects of artichoke have been
*Corresponding author. E-mail: heidarian_e@skums.ac.ir/
heidarian46@yahoo.com. Tel: +98 381 3346720. Fax: +98 381
3346721.
documented in experimental and clinical studies (Joy and
Haber, 2007; Shimoda et al., 2003). Also, artichoke is full
of natural bioactive components, that is, caffeic acid,
chlorogenic acid, cynarin, and luteolin. These
components reduce the production of reactive oxygen
species (ROS), lipid peroxidation and the oxidation of low
density lipoproteins (LDL) in vitro experiments (Juzyszyn
et al., 2008; Wang et al., 2003; Zapolska-Downar et al.,
2002). Therefore, these properties of artichoke warrant its
application in traditional medicine.
Phosphatidate phosphohydrolase (PAP, EC 3.1.3.4)
catalyzes the dephosphorylation of phosphatidic acid to
yield inorganic phosphate (Pi) and 1, 2 diacylglycerol.
This enzyme is a regulatory step in controlling the
synthesis of glycerophospholipids and triacylglycerols
(Carman and Han, 2006). The produced diacylglycerol
serves as a precursor for the biosynthesis of major
glycerolipids in animal cells (Carman and Han, 2006;
Fleming and Yeaman, 1995). In addition, triglyceride (TG)
serves as an important storage molecule that allows
organism to survive periods of food deprivation. In human
diseases, the regulation of TG storage is very important
because both excessive and inadequate fat storage are
accompanied with dyslipidemia, insulin resistance, and
diabetes (Petersen and Shulman, 2006; Reue and Phan,
2006). In rat liver, two distinct forms of PAP have been
reported based on N-ethylmaleimide (NEM) sensitivity
(Carman and Han, 2006; Heidarian and Haghighi, 2008).
The NEM-sensitive form (PAP1), located in cytosol and
microsomal fraction, requires mmagnesium ion (Mg2+) for
its activity and is a regulatory enzyme in TG and
phospholipids biosynthesis (Carman and Han, 2006). The
second form is PAP2. It presents in plasma membrane
and does not require Mg2+ for its activity. This form is
primarily involved in lipid signaling pathways by
modulating the second messengers of diacylglycerol and
phosphatidic acid (Brindley, 2004; Sciorra and Morris,
2002).
Most of the previous studies on artichoke have shown
that artichoke has cholesterol and TG lowering effects
(Joy and Haber, 2007; Shimoda et al., 2003). A study has
shown the inhibition effect of artichoke on HMG-CoA
reductase in the cholesterol biosynthesis pathway
(Gebhardt, 1998). Nevertheless, most of the previous
studies on artichoke focus less on enzyme involving in
TG metabolism, especially PAP enzyme, in details. To
the best of our knowledge, there is no study investigating
the effect of artichoke on PAP in hypercholesterolemic
animals or humans. Therefore, the aim of this study was
to determine the effects of dietary supplementation with
artichoke on the liver PAP, plasma lipids, liver TG
content, plasma antioxidant, and malondialdehyde (MDA)
levels in hyperlipidemic rats.
MATERIALS AND METHODS
Chemicals
Phosphatidic acid (sodium salt), dithiothreitol (DTT), 2,4,6-tripyridyl-
s-triazine (TPTZ) and phenylmethylsulfunyl fluoride (PMSF) were
purchased from Sigma (Sigma Chemical Co., USA). Sodium
tetraborate, bovine serum albumin, Tris–HCl, ethylenediaminetetra
acetic acid (EDTA), ethyleneglycol-bis (beta-aminoethyl ether)-
N,N,N',N'-tetraacetic acid (EGTA), sucrose, 2-thiobarbituric acid
(TBA), and f erric chloride (FeCl3.6H2O) were provided from Merck
(Germany). All other chemicals used were of analytical grade.
Preparation of artichoke
The artichoke used in our study was obtained from Isfahan
Agricultural Research Center (Iran). Then, the 10% artichoke pellets
were made by mixing 10 g of dried and crushed artichoke with 90 g
of powdered standard rat pellet diet.
Animals and experimental design
Male wistar albino rats (150-200 g) were maintained at approxi-
mately 22°C with a 12 h light/12 h darkness cycle, and had
Heidarian et al. 4919
free access to food and tap water. They were r andomly divided into
4 diet groups (n = 6/ group) as shown. Group 1, normal control rats
which received standard pellet chow; Group 2, animal rats fed with
a standard pellet chow supplemented with 10% artichoke; Groups 3
and 4, the rats fed with a lipogenic diet c ontaining standard pellet
chow supplement ed with 0.5% cholic acid, 20% sunflower oil, and
2% cholesterol for 2 weeks to produce hyperlipidemia. Additionally,
Groups 3 and 4 drank water containing 3% ethanol (Yanardag et
al., 2005). In Group 3, after 2 weeks, 10% artichoke was added into
lipogenic regime for 45 days, whereas the rats in Group 4 were
maintained on lipogenic diet (hyperlipidemic control group). On the
60 of the experiment, fasted animals anesthetized with chloroform
and their blood samples were collected in test tubes containing
EDTA through cardiac puncture. All plasma specimens were
separated by low speed centrifugation (2000 g) for 10 min and were
stored at -80°C until they were analyzed. All animal procedures
were performed with regard to Iranian animal ethics society and
local university rules.
Analytical procedures
Total cholesterol (TC), plasma TG and high density lipoprotein
cholesterol (HDL-C) levels were determined by enzymatic method
(Pars Azmun kit, Iran) with JENWAY spectrophotometer (model
6105, England). Low density lipoprotein cholesterol (LDL-C) and
very low density lipoprotein cholesterol (VLDL-C) were calculated
with Fridewald formula . Liver TG was extracted from liver tissue by
Folch-altered method which invented by Norman (1969).
Preparation of rat liver homogenate
The liver of each rat was perfused through the inferior vena cava
with ice-cold saline (0.9%) to remove blood and Pi from it to assess
the liver PAP activity and the liver content TG. A portion of perfused
liver was homogenized in 4 volumes of ice-cold buffer (pH 7.4)
containing 50 mM Tris–HCl, 0.25 M sucrose, 1 mM PMSF and 0.1
mM EDTA by homogenizer (Heidolph, Silentcrusher M model,
Germany) at 8000 rpm at 4°C for 5 min (Haghighi and Honarjou,
1987). The homogenate was centrifuged at 4500 rpm at 4°C for 10
min and then, the supernatant kept for the enzyme assay.
Determination of PAP activity
PAP activity was measured in the ass ay buffer (250 µl) contain ing
50 mM Tris–HCl (pH 7.4), 1 mM EGTA, 1 mM DTT, 1 mM EDTA, 2
mM Mg Cl2, 0.35 mM phosphatidate, and appropriate amount of the
enzyme s olution. After 10 min incubation at 37°C, the reaction was
stopped by addition of 0.5 ml trichloroacetic acid (10%). Hence, the
released Pi was measured ( Haghighi and Honarjou, 1987). All PAP
activity assays were linear in r elation to the protein concentrations
and the incubation time used in them. The release of 1 µmole of Pi
per min was defined as one unit (U) of PAP activity. Specific activity
was considered as units per mg protein. Protein c oncentration was
determined by method of Bradford (1976).
Measurement of malondialdehyde
The plasma MDA level was determined using TBA according to the
method of Ohkawa et al. (1979). The plasma samples were
incubated for 1 hour at 95°C with TBA, after the reaction of MDA
with TBA, the reaction product was followed spectrophotometrically
at 532 nm. The measurements were done in duplicates and the
results were expressed in µM. MDA standards were prepared from
4920 J. Med. Plant. Res.
Table 1. The specific activity of PAP and liver triglyceride in experimental groups.
Group PAP activity (nmolPi/min/mg protein) Liver TG (mg/g tissue)
1 ( control) 9.41 ± 0.39 3.80 ± 0.39
2 8.52 ± 0.90*# 2.64 ± 0.35*
3 6.46 ± 0.61* 5.16 ± 0.10*#
4 6.73 ± 0.27* 7.38 ± 0.52*
The data were expressed as mean ± S.D; n= 6 in each group; G roup 1, normal control; Group 2, control
supplemented with10% artichoke; Group 3, hyperlipidemic rats treated with 10% artichoke; Group 4,
hyperlipidemic rats without treatment * P < 0.05 compared with the corresponding value f or group 1 (normal
control animals); #P < 0.001 compared with the corresponding value for group 4 (hyperlipidemic animals).
Table 2. Effect of artichoke on TC, TG, LDL-C, HDL-C, VLDL-C levels and atherogenic index in hyperlipidemic rats.
Group TC (mg/dl) TG (mg/dl) HDL-C (mg/dl) LDLC (mg/dl) VLDL (mg/dl) Atherogenic index (unit)
TC/HDL-C LDL/HDL-C
1 87.71 ± 13.61 56.98±6.22 51.67±5.39 23.52±2.07 10.50±2.43 1.70±0.16 0.47±0.13
2 53.36 ± 7.34* 46.68±4.62 41.32±2.16* 4.94±1.82* 9.45±1.10 1.29±0.10* 0.11±0.05*
3 79.20 ± 6.75** 49.01±6.10** 52.13±2.87 17.43±2.51** 9.80±2.34** 1.52±0.03** 0.33±0.05**
4 146.25 ± 29.93# 75.56±4.07# 58.41±8.72 70.67±10.81# 15.11±0.95
#
2.42±0.26* 1.21±0.23*
The data are expressed as mean ± S.D; n= 6 in each group; Group 1, normal c ontrol; Group 2, control supplemented with 10% artichoke;
Group 3, hyperlipidemic rats treated with 10% artichoke; Group 4, hyperlipidemic rats without treatment * P < 0.001 compared with the
corresponding value for Group 1 (normal control animals); ** P < 0.001 compared with the corresponding value for Group 4 (lipogenic
regime); # P < 0.001 compared with the corresponding value for Groups 1 and 2.
1,1,3,3-tetraethoxypropane (TEP).
Ferric reducing/antioxidant power (FRAP) assay
The antioxidant c apacity of each sample was measured according
to the procedure described by Benzie and Strain (1996). In this
method, the complex between iron (II) ion (Fe2+) and TPTZ gives a
blue color with absorbance at 593 nm. Ferrous sulfate heptahydrate
(FeSO4.7H2O) was used as a standard of FRAP assay at a
concentration range between 100 to 1000 µM.
Statistical analysis
All data were expressed as mean ± standard deviation (S.D). The
data were analyzed by statistical package for the social sciences
(SPSS) software (version 11.5). Data were analyzed using one-way
analysis of variance (ANOVA) followed by Tukey post hoc test for
multiple comparison. Differences were considered significant at P <
0.05 level.
RESULTS
Table 1 summarizes the effect of artichoke on the liver
TG and PAP activity in experimental groups. Group 2
showed a significant reduction (P < 0.05) in the liver PAP
activity compared to Group 1. No significant change (P >
0.05) was observed in liver PAP activity of Group 4
compared to Group 3. Also, there was a noticeable
reduction (P < 0.05) in PAP activity between Groups 3
and 4 compared to Group 1. Group 4 showed a
significant increase (P < 0.001) in the liver TG in
comparison with Groups 1 and 3. The liver TG declined
(P < 0.05) in Groups 2 and 3 compared with Groups 1
and 4, respectively.
Effect of artichoke on plasma lipid levels
Table 2 shows the mean plasma levels of TG, TC, HDL-
C, LDL-C, VLDL-C, and atherogenic index in experi-
mental groups. The levels of plasma TG, TC, VLDL-C,
and LDL-C in Group 4 (consuming lipogenic diet) were
significantly increased (P < 0.05) compared to other
groups. The plasma HDL-C in Group 3 had no significant
change (P > 0.05) compared with Group 4. In Groups 2
and 3, the plasma level of cholesterol significantly
decreased (P < 0.001) in comparison with Groups 1 and
4, respectively. On the other hand, the plasma level of
TG in Group 3 (consuming oil and cholesterol diet
supplemented with10% artichoke) significantly decreased
(P < 0.001) compared to Group 4. In Group 2 the plasma
levels of HDL-C and LDL-C significantly decreased (P <
0.001) compared to Group 1. VLDL-C in Group 3 showed
an important reduction (P < 0.001) compared with Group
4. There was a significant (P < 0.001) elevation in
atherogenic index (TC/HDL-C and LDL/ HDL-C) of Group
4 with respect to Group 1 while, a significant reduction (P
< 0.001) was observed in groups 2 and 3 compared with
1
2
3 4
Figure 1. Plasma MDA levels in Groups 1 to 4. Group 1, normal
diet; Group 2, normal diet supplemented with 10% artichoke;
Group 3, hyperlipidemic rats treated with 10% artichoke; Group 4,
hyperlipidemic rats without treatment. The data are expressed as
mean ± S.D; n=6 in each group; #P < 0.001 c ompared with the
corresponding value for normal control animals; *P < 0.001
compared with the corresponding value for hyperlipidemic rats
without treatment.
1
2
3 4
Figure 2. Plasma antioxidant capacity (FRAP) in Groups 1 to
4. Group 1, normal diet; Group 2, normal diet supplemented
with 10% artichoke; Group 3, hyperlipidemic rats treated with
10% artichoke; Group 4, hyperlipidemic rats without treatment .
The data are expressed as mean ± S.D; n=6 in each group; #
P < 0.05 compared with the c orresponding value for normal
control animals. * P < 0.05 compared with the corresponding
value for hyperlipidemic rats without treatment.
Heidarian et al. 4921
Groups 1 and 4, respectively.
Effect of artichoke on the plasma level of MDA
Figure 1 shows that plasma MDA was significantly
increased (P < 0.05) in Group 4 after the consumption of
lipogenic diet when compared with other groups. On the
other hand, in Group 2 the consumption of artichoke led
to a significant (P < 0.001) reduction of plasma MDA in
comparison with Group 1 (control). Also, in Group 3 a
significant (P < 0.001) reduction of plasma MDA was
seen as compared with Group 4.
Effect of artichoke on the plasma level of antioxidant
power
Figure 2 shows the plasma antioxidant values in each
experimental group. At the end of the work, a significant
increase (P < 0.05) was found in the plasma FRAP
values of Group 2 compared to the Groups 1 and 4. Also,
a significant reduction (P < 0.001) was observed in the
plasma FRAP values between Groups 3 and 4.
DISCUSSION
Hyperlipidemia with serum elevated concentrations of
cholesterol and triacylglycerol is considered to be the
cause of cardiovascular disease (Frishman, 1998).
Treatment of hyperlipidemia needs diet control, exercise,
and using lipid-lowering compounds such as drugs and
diet (Stone, 1996). Lipid-lowering drugs such as fibrates
and bile acid sequestrants were used for many years.
Nevertheless, the side effects of drugs led to synthesis
new oral antihyperlipidemic drugs such as statins (HMG
CoA reductase inhibitors). Although the side effect of
statins is relatively low but, they can cause rhabdo-
myolysis condition (Miller, 2001). Therefore, the research
for natural compounds with lipid-lowering properties and
with less or no adverse effects, especially medicinal
plants, is warranted. These plants contain biological
active substances including antioxidant, hypoglycemic,
and hypolipidemic compounds. Unfortunately, there is
less information about enzymatic or lipid-lowering mecha-
nisms for many of these medicinal plants, especially their
effects on PAP enzyme. In this respect, we reported the
effect of garlic on the liver PAP activity in normal and
hyperlipidemic rats (Heidarian et al., 2011). The
supplementation of garlic, as a medicinal plant, led to
reducing liver PAP enzyme and liver TG. In this study,
our data have shown that artichoke supplementation in
hyperlipidemic rats lead to highly effective in reducing
plasma cholesterol and LDL levels as compared to the
high cholesterol and control diet groups (Table 2). Also,
artichoke caused significant decreases in TG and the
4922 J. Med. Plant. Res.
ratio of cholesterol to HDL cholesterol in plasma of rats
fed by lipemic diet. Lipid-lowering effects of artichoke
have been reported by other investigators (Küskü-Kiraz
et al., 2010; Shimoda et al., 2003). Studies on cultured
hepatocytes suggested that artichoke inhibits the
incorporation of 14C-labelled acetate into the non-
saponifiable lipid fraction and thus reduces the
cholesterol biosynthesis. Luteolin, a flavonoid constituent
of artichoke, was found to play a major role in the
inhibition of cholesterol biosynthesis and reduction of
serum cholesterol (Gebhardt, 1998). Moreover, chloro-
genic acid is another bioactive component of artichoke
that reported as lipid-lowering agent in the artichoke (Joy
and Haber, 2007; Wider et al., 2009). Nevertheless, the
published works do not assess the effect of artichoke on
PAP activity and liver TG in hyperlipidemic rats. In our
study the artichoke supplementation results in higher
reduction of PAP activity (Table 1) and liver TG in Group
2 than Group 1 (control). Although, the reduction of the
plasma TG in Group 2 was not significant, it was
accompanied with a decline in the liver PAP activity in
this group (Tables 1 and 2). On the other hand, in
animals fed by lipemic regime (Groups 3 and 4) PAP
activity decreased with respect to control group whereas,
their liver TG concentration increased in this study (Table
1). It has been reported that excessive intake of fatty
acids results in accumulation of TG in many tissues,
especially in fat tissue and non-adipose tissues such as
liver (van Herpen and Schrauwen-Hinderling, 2008). In
addition, it was shown that fatty acid esters lead to the
inactivation of PAP. Fatty acids and their acyl-CoA esters
regulate PAP by a negative allosteric interaction. The
formation of PAP fatty acid (or acyl-CoA esters) complex
results in the inactivation of PAP (Elabbadi et al., 2005).
Therefore, the reduction of PAP activity in this study in
groups fed with high lipid regime (Groups 3 and 4) is due
to the accumulation of TG, fatty acids or acyl-CoA esters
in the liver (Table 1). Nevertheless, the reduced activity of
PAP in groups fed with high lipid regime (Groups 2 and 3)
can probably act as a defense mechanism of liver for
reducing the production of endogenous liver TG. Thus,
serum and liver TG will decline and likely, reduce the risk
of liver damage especially fatty liver and cirrhosis.
Besides, in our study liver fat concentration significantly
increased in animal groups fed by lipogenic regime
(Groups 3 and 4) compared to the Group 1 (normal
control). The elevated liver fat in Group 3 was
significantly reduced as opposed Group 4 (Table 1)
through the supplementation with artichoke. Therefore,
the artichoke leaves can be able to reduce the liver
content of TG by diminishing PAP activity. Overall,
artichoke can be useful in lowering and the treatment of
fatty liver in hyper-lipidemic regime. Moreover, the
artichoke supplemen-tation with lipogenic regime led to
reduction of plasma LDL-cholesterol and atherogenic
index. These results indicate that artichoke can be
applicable for reducing the coronary heart diseases in
hyperlipidemic conditions.
In this study, we did not evaluate the effects of
artichoke on the other enzymes involving in the lipid
metabolism, especially glucose-6-phosphate dehydro-
genase (G6PDH) and malic enzyme. These enzymes
generate nicotinamide adenine dinucleotide phosphate
(NADPH) employed for fatty acid and cholesterol
syntheses. We suggest that future studies focus on other
possible mechanisms of the TG lowering action of the
artichoke or the bioactive components of artichoke on the
mentioned enzymes.
Oxidative stress of plasma lipoproteins, erythrocytes
and several tissues such as liver, heart and aorta have
been reported in experimental animals fed on high
cholesterol diet (Jemai et al., 2008; Küskü-Kiraz et al.,
2010; Sudhahar et al., 2007). Increased oxidative stress
parameters have been detected in hypercholesterolemic
individuals (Ondrejovičová et al., 2010). The level of MDA
is considered as a biomarker of lipid peroxidation
(Lykkesfeldt, 2007). In the present study, artichoke
supplementation caused significant decreases in plasma
lipid peroxidation together with elevation of plasma
antioxidant power (Figure 1 and 2). In this respect, there
are published reports concordant with our results
(Juzyszyn et al., 2010; Küskü-Kiraz et al., 2010).
Artichoke is known to have antioxidant effect. Previous
studies have reported that the antioxidant potential of
artichoke is dependent on radical scavenging by its
constituents such as cynarin, chlorogenic acid and
flavonoids such as caffeoylquinic acids (Brown and Rice-
Evans, 1998; Pérez-Garcia et al., 2000). Both caffeoyl-
quinic acids and flavonoids present in artichoke are
considered to be responsible for its anti-atherogenic
actions through their antioxidant capacity (Wang et al.,
2003). The antioxidant barriers of the artichoke extract’s
constituents rely on the inhibition of ROS generation,
ROS neutralization, or the induction of endogenous
antioxidants (Jiménez-Escrig et al., 2003; Juzyszyn et al.,
2008; Pérez-Garcia et al., 2000). Therefore, on the basis
of our results, artichoke can probably play an anti-athero-
genic role by lowering lipids oxidation in hyperlipidemic
diets.
Conclusion
Our findings indicate that artichoke can be useful to
decrease PAP activity, liver TG, oxidative stress, plasma
cholesterol, and TG levels in hyperlipidemic rats. Also,
artichoke has beneficial effects in the control of fatty liver,
plasma lipid abnormalities, hyperlipidemia, and oxidative
stress in hyperlipidemic diet conditions.
Abbreviations
PAP, Phosphatidate phosphohydrolase; TG, triglyceride;
ROS, reactive oxygen species; LDL, low density
lipoproteins; HDL, high density lipoprotein; Pi, inorganic
phosphate; NEM, N-ethylmaleimide; PAP1, Mg2+,
mmagnesium ion; MDA, malondialdehyde; DTT,
dithiothreitol; TPTZ, 2,4,6-tripyridyl-s-triazine; PMSF,
phenylmethylsulfunyl fluoride; EDTA, ethylenedi-
aminetetra acetic acid; EGTA, ethyleneglycol-bis (beta-
aminoethyl ether)-N,N,N',N'-tetraacetic acid; TBA, 2-
thiobarbituric acid; FeCl3.6H2O, ferric chloride; TC, total
cholesterol; HDL-C, high density lipoprotein cholesterol;
LDL-C, low density lipoprotein cholesterol; VLDL-C, very
low density lipoprotein cholesterol; TEP, 1,1,3,3-
tetraethoxypropane; Fe2+, iron (II) ion; FeSO4.7H2O,
ferrous sulfate heptahydrate; S.D, standard deviation;
SPSS, statistical package for the social sciences;
ANOVA, analysis of variance; G6PDH, glucose-6-
phosphatedehydrogenase; NADP, Nicotinamide adenine
dinucleotide phosphate.
ACKNOWLEDGEMENT
This study was funded by Ilam University of Medical
Sciences, Ilam. Iran. Also, authors great thanks to Dr.
Hossein Zeinali for his help to provide and identify the
artichoke from Isfahan Agricultural Research Center
(Iran).
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