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Effects of ID-alG™ on Weight Management and Body Fat Mass in High-Fat-Fed Rats

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Seaweed extract of Ascophyllum nodosum, ID-alG™, was evaluated for its chronic effects on weight management in high-fat-fed Sprague-Dawley rats. ID-alG™ was orally administered daily during 9 weeks at doses of 40 and 400 mg/kg/day with fat-enriched diet (FED) in comparison with two control groups consuming standard diet (negative control) or FED (positive control) and orally treated with vehicle. Body weight, percentage of body fat mass and lipid parameters were measured. After 9 weeks, the oral administration of ID-alG™ at both doses decreased significantly the mean body weight gains (MBWG) of rats submitted to the FED in comparison to the positive control (-6.8% and -11.8%). ID-alG™ at both doses improved significantly the MBWG of rats and decreased significantly the percentage of body fat mass of rats (-9.8% and -19.0%), in comparison to the positive control. In the same way, the triglyceride blood level was also significantly improved for the dose of 400 mg/kg/day (-30.6% vs. +49.9% for the positive control); and the dose of 40 mg/kg/day just lead to a trend. Moreover, in both controls and ID-alG™-treated groups, total cholesterol, LDL and HDL blood levels were not modified. The seaweed extract of Ascophyllum nodosum, ID-alG™, demonstrated beneficial effects on weight management of rats submitted to a high-fat diet.
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Effects of ID-alG
on Weight Management and
Body Fat Mass in High-Fat-Fed Rats
Kathleen Terpend,
1
*Jean-François Bisson,
2
Claire Le Gall
1
and Elodie Linares
1
1
BIO SERAE Laboratoires S.A.S., 129 chemin de Croisset. BP 4151, 76723 Rouen, cedex 3, France
2
ETAP S.A., 13 rue du Bois de la Champelle, Parc Technologique de Nancy-Brabois, 54500 Vandœuvre-lès-Nancy, France
Seaweed extract of Ascophyllum nodosum, ID-alG
, was evaluated for its chronic effects on weight manage-
ment in high-fat-fed Sprague-Dawley rats. ID-alG
was orally administered daily during 9 weeks at doses of
40 and 400 mg/kg/day with fat-enriched diet (FED) in comparison with two control groups consuming standard
diet (negative control) or FED (positive control) and orally treated with vehicle. Body weight, percentage of
body fat mass and lipid parameters were measured. After 9 weeks, the oral administration of ID-alG
at both
doses decreased signicantly the mean body weight gains (MBWG) of rats submitted to the FED in comparison
to the positive control (6.8% and 11.8%). ID-alG
at both doses improved signicantly the MBWG of rats
and decreased signicantly the percentage of body fat mass of rats (9.8% and 19.0%), in comparison to the
positive control. In the same way, the triglyceride blood level was also signicantly improved for the dose of
400 mg/kg/day (30.6% vs. +49.9% for the positive control); and the dose of 40 mg/kg/day just lead to a trend.
Moreover, in both controls and ID-alG
-treated groups, total cholesterol, LDL and HDL blood levels were
not modied. The seaweed extract of Ascophyllum nodosum, ID-alG
, demonstrated benecial effects on
weight management of rats submitted to a high-fat diet. Copyright © 2011 John Wiley & Sons, Ltd.
Keywords: ID-alG
; Ascophylum nodosum; seaweed; weight management; lipase inhibition; a-amylase inhibition.
INTRODUCTION
Weight management and the development of new ingre-
dients possibly having a benecial effect on the obesity
epidemic are two of today's major challenges. Over-
weight and obesity problems are clearly linked to an
increase in plasma triglycerides and also lead to a modi-
cation of the cholesterol prole, which are known to be
risk factors incoronary heart disease (Wildman et al.,
2008). Triglyceride is a glyceride in which the glycerol
is esteried with three fatty acids. It is the main constitu-
ent of vegetable oil and animal fats. Triglycerides are
formed from a single molecule of glycerol, combined
with three fatty acids on each of the OH groups, and
make up most of the fats digested by humans. That is
where the enzyme pancreatic lipase acts on. Ester bonds
form between each fatty acid and the glycerol molecule,
hydrolysing the bond and releasingthe fatty acid
(Dubois et al., 1994). Whereas the triglyceride form
cannot be absorbed by the duodenum, fatty acids,
monoglycerides and some diglycerides are absorbed by
the duodenum. Triglycerides, as major components of
very low density lipoprotein (VLDL) and chylomicrons,
play an important role in metabolism as energy sources
(Bracco, 1994). They contain more than twice as much
energy (9 kcal/g) as carbohydrates and proteins. In
the human body, high levels of triglycerides in the
bloodstream have been linked to atherosclerosis
(Gandotra and Miller, 2008), and, by extension, to the
risk of heart disease and stroke (Talmud et al., 2004;
Alagona, 2009). Therefore promoting weight loss and/
or preventing weight regain may lead to improvement
in triglyceride metabolism and reduce risk factors.
ID-alG
is produced from the brown alga Ascophyllum
nodosum (Fucacea family) using grape extract as a carrier
(<5%). This brown alga is known to contain specic
polyphenols, phologlucinol (Pavia and Brock, 2000) and,
in polymeric form, phlorotannins (Shibata et al., 2004;
Audibert et al., 2010).
Some evidence for the effect of polyphenol compo-
nents on digestive enzymes has been reviewed previously
(Kandra et al., 2004; McDougall and Steward, 2005;
McDougall et al., 2005; Li et al., 2007; Lee et al., 2007;
Adisakwattana et al., 2010; Kawakami et al., 2010).
Extracts from Ascophyllum nodosum were found to
inhibit rat intestinal a-glucosidase and to stimulate basal
glucose uptake into 3 T3-L1 adipocytes (Zhang et al.
2007). This a-glucosidase inhibition was associated
with the polyphenolic components of the Ascophyllum
nodosum extracts (Apostolidis and Lee, 2010) and an
enriched polyphenolic fraction was shown to reduce the
rise in blood glucose after an oral sucrose tolerance test
in diabetic mice (Zhang et al., 2007). The crude polyphe-
nol extract and an enriched polyphenolic fraction had
decreased blood total cholesterol and glycated serum
protein levels compared with untreated diabetic mice,
whereas the crude polyphenol extract also normalized
the reduction in liver glycogen level that occurred in
diabetic animals. Seaweed Ascophyllum nodosum
extracts containing phlorotannins were also found to be
active on differentiation and fatty acid accumulation
in differentiating 3 T3-L1 adipocytes (He et al., 2009).
* Correspondence to: Kathleen Terpend, BIO SERAE Laboratoires S.
A.S., 129 chemin de Croisset, BP 4151, 76723 Rouen Cedex 3, France.
E-mail: k.terpend@bioserae.com
The new scientic data included in this publication are considered propri-
etary to BIOSERAE, in particular according to article 21 of the Regulation
EC No 1924/2006 on nutrition and health claims made on foods and other
pertaining provisions of the EC General Food Law.
PHYTOTHERAPY RESEARCH
Phytother. Res. (2011)
Published online in Wiley Online Library
(wileyonlinelibrary.com) DOI: 10.1002/ptr.3619
Copyright © 2011 John Wiley & Sons, Ltd.
Received 05 November 2010
Revised 23 June 2011
Accepted 25 June 2011
Other extracts from marine algae were also found to
inhibit a-glucosidase, a-amylase (Heo et al., 2009) and
lipase (Bitou et al., 1999; Ben Rebah et al., 2008).
The inhibition properties of the polyphenolic compo-
nents of Ascophyllum nodosum,ona-glucosidase and
a-amylase, were particularly studied in order to deter-
mine their potential application on the prevention of
hyperglycemia. The relationship between polyphenol
extracts characterized by inhibition properties of diges-
tives enzymes and weight management has been studied
in polyphenols other than that of Ascophyllum nodosum.
Some in vivo studies were performed on hypercaloric diet
models (high-fat diet) showing antiobesity and hypolipi-
demic effects of polyphenols in relation to their inhibition
properties in digestive enzymes (Bose et al., 2008; Han
et al., 2003; Uchiyama et al., 2011; Yang et al., 2010). Han
et al. (2003) showed that the inhibitory effects of the poly-
phenol fraction of S. matsudana leaves on obesity induced
by a high-fat diet might be due to the inhibition of carbo-
hydrate and lipid absorption from the small intestine
through the inhibition of a-amylase. On mice fed with a
high-fat diet, polyphenols of tea suppressed increases in
body weight, parametrial adipose tissue mass and liver
lipid content, and these healthy effects were related to
the inhibition of intestinal lipid absorption (Uchiyama
et al. 2011).
The aim of this study was to determine the lipase and
a-amylase inhibitory properties of ID-alG
in an
in vitro model and to investigate the chronic effects of
ID-alG
in female Sprague-Dawley rats, on a high-fat-
diet model, using two doses (40 and 400 mg/kg/day)
orally administered over a period of 9 weeks. Measure-
ments of body weight, body fat mass, triglycerides, cho-
lesterol, HDL and LDL blood levels were performed at
the beginning and the end of the study. The drink and
food intakes were recorded three times per week.
MATERIAL AND METHODS
ID-alG
is a manufactured ingredient produced by
Bioserae and obtained from thallus of brown alga,
Ascophyllum nodosum (Fucaceae family) using Vitis
vinifera grape extract as a carrier (<5%) (Bioserae
condential process).
In vitro models (enzymatic activity). Pre-tests were per-
formed in order to determine the effect of ID-alG
on
the enzymatic activities of lipase and a-amylase in
in vitro models.
Measurement of lipase activity. The enzymatic activity
of lipase (Lipase Candida rugosa, Ref. Sigma L-1754
at a concentration of 1000 units/mL) was determined
using pure olive oil as a substrate (1.5 mL) and the
released fatty acid was quantied by a titrimetric
method adapted from Sigma (EC 3.1.1.3 (1993) Reagent
Chemicals ACS Specication, 8th edn, 95). The hydro-
lyse of pure olive oil was performed at 37 C and at
pH 7.2 during 30 min and the released fatty acid was
measured by NaOH titration under blue colour reagent
(Thymolphthalein, Ref. Sigma T-0626). The control
used was olive oil with added lipase and was considered
as the positive control (100% lipase activity). The meas-
urement of the effect of ID-alG
on the lipase activity
was calculated from the same assay plus the product
ID-alG
reacting as an inhibitor.
The inhibitory effect of ID-alG
on the release of
fatty acid was determined at 50 mg/L and the percentage
of enzymatic inhibition was expressed as:
% inhibition ¼100 Vinh 100
Vmax
where V
inh
is the volume in millilitres of NaOH used to
obtain a light blue colour in the presence of ID-alG
at
50 mg/L, and V
max
is the volume in millilitres of NaOH
used to obtain a light blue colour without any inhibitor.
Measurement of a-amylase activity. The enzymatic ac-
tivity of a-amylase (amylase from porcine pancreas,
Ref. Sigma A-3176 at a concentration of 1.9 units/mL)
was determined with potato starch as substrate (10 mg
of potato starch, 1% solution in water previously boiled)
and the released maltose was quantied by a colorimet-
ric method adapted from Sigma Procedure (EC 3.2.1.1.;
Bernfeld, P. (1955) Methods in Enzymology 1, 149158).
The hydrolysis of starch was performed at 37 C (body
temperature), at pH 6.9 during 3min, and the reaction
was stopped with sodium potassium tartrate (Ref. Sigma
S-2377) and 3,5-dinitrosalicylic acid (Ref. Sigma D-0550)
colour reagent in a boiling water batch for 15 min and
cooled at room temperature. Then, the released maltose
was measured by absorbance at 540 nm. The control used
was potatoes starch added with the amylase and was
considered as the positive control (100% amylase activ-
ity). The measurement of the effect of ID-alG
on the
a-amylase activity was calculated from the same assay
plus the product ID-alG
reacting as an inhibitor.
The inhibitory effect of ID-alG
on the release of
maltose was determined at 41 mg/L and the percentage
of enzymatic inhibition was expressed as:
% inhibition ¼100 Ainh 100
Amax
where A
inh
is the absorbance level at 540nm in the pres-
ence of ID-alG
at 41 mg/L, and A
max
is the maximal
absorbance level at 540 nm without any inhibitor. For
both conditions (A
inh
and A
max
) the values of absorbance
were determined taking into account sample blanks.
In vivo model: high-fat-fed rats.
Animals and obesity induction. Twenty-four female
Sprague-Dawley rats, weighing 170180 g at the start
of the experiment, were obtained from the Centre
d'élevage HARLAN France(Gannat, France). Ani-
mals were identied and placed two per cage in an air-
conditioned room under controlled conditions of
temperature (22 2C), relative humidity (50 10%),
with an inverted 12-h light:dark cycle (light off at
08:00 hours) and they had access to standard diet
TD.94045 or the fat-enriched diet TD.06414 (Harlan
Teklad, US, Madison), which are described in Table 1.
During the quarantine period, rats received the standard
diet TD.94045 (Harlan Teklad US, Madison, U.S.A.), with
water provided ad libitum. After one week of
acclimatization, rats were weighed and randomly divided
into four groups (n= 6): one group received the standard
diet TD.94045 for the last 8 weeks (negative control) and
three groups received the fat-enriched diet TD.06414 for
K. TERPEND ET AL.
Copyright © 2011 John Wiley & Sons, Ltd. Phytother. Res. (2011)
the induction of obesity for the same duration (8 weeks).
For two of the three groups receiving the fat-enriched diet
TD.06414, ID-alG
was freshly dissolved each day in
spring water (source Cristaline Aurèle, France) prior to
oral administration by intragastric gavage, with an admin-
istration volume of 10 ml/kg: one group at the dose of
40mg/kg/day(20mg/kginthemorningandthesamedose
in the afternoon), the other group at the dose of 400 mg/kg/
day(200mg/kginthemorningandthesamedose in the
afternoon). The oral treatments with ID-alG
began
1 week before the induction of obesity. The dose used
for rats corresponded to our recommended daily dosage
of ID-alG
for humans (400 mg per day) during the meal.
The animal care unit is authorized by the French
Ministres of Agriculture and Research (Government
Authorization No. A 54-547-1), the protocol was
approved by the local ethical committee and the animal
experiments were performed according to the European
guidelines for animal experimentation (European
Communities Council Directive no. 86/609/EEC of 24
November 1986), the rules provided by the ASAB Eth-
ical Committee (2006) and the Canadian Council on
Animal Care (2003).
Assessment of weight gain management. The food and
drink intakes of all the cages of rats were recorded three
times per week in order to measure the ingested quan-
tities of diet and water per rat.
On Day 0 (D0), 24 hours before the beginning of the
oral treatments and on Day 64 (D64), 24 hours after the
last oral treatment, an EM scan was performed on all
rats to determine the percentage of body fat mass. Rats
were anesthetized by intraperitoneal injections of ace-
promazine (Calmivet, Vetoquinol, Lure, France) at the
dose of 2 mg/kg and ketamine (Ketamine 1000, Virbac,
Carros, France) at the dose of 50 mg/kg. Rats were then
placed in the EM scan chamber (EM-Scan/TOBEC
W
,
Model SA-3114 Detection Chamber, Swantech Inter-
national, Gennevilliers, France) and ve measurements
of the total body electrical conductivity were performed
for each rat (with a standard error <3.0%) in order to
determine the percentage of the body fat mass.
Assessment of lipidic parameters. On D0, 24 hours
before the beginning of the oral treatments and on
D64, 24 hours after the last oral treatment, a blood
sample of 1.5 mL was performed on each rat from the
caudal vein in a dry tube (Térumo, Leuven, Belgium),
without anesthesia.
The blood samples were placed at +4 C for 20 to
30 min for blood clotting and centrifuged at 1500 g
for 15 min. Serums were then collected in polypropylene
tubes, frozen at 20 C and stored at 80 C until per-
forming lipidic status with dosage of triglycerides, total
cholesterol, HDL and LDL levels. Dosages were per-
formed by the Laboratory of Medical Analysis Aubert
(Vandœuvre-lès-Nancy, France) using a biochemical
automate (Kone Prime 60, Thermo Fisher Scientic
Inc., Cergy-Pontoise, France) under the responsibility
of Doctor M.-C. Dederichs (PharmD, Doctor Biologist
and Director of the Laboratory of Medical Analyses).
Statistical analyses. Results are expressed as mean
standard error of the mean (SEM). The weight and
weight gain of rats, the body fat mass and the blood
levels of triglycerides, total cholesterol, HDL and LDL
were analysed at the end of the experiment. Statistical
analyses of the data were performed using the Krus-
kallWallis test (non-parametrical ANOVA). When sig-
nicance was observed, the MannWhitney U-test was
used to compare treated groups with the control groups.
For all the comparisons, differences were considered to
be signicant at the level of p<0.05. All statistical ana-
lyses were carried out using the StatView
W
5 statistical
package (SAS Institute, Inc., Cary, NC, USA).
RESULTS
Effect of ID-alG
on lipase and a-amylase activities
For the lipase activity using the titrimetric method with
NaOH titration and measured with a solution of
ID-alG
at 50 mg/L on 30 batches, ID-alG
induced
a decrease in the lipase activity of 71.0 2.0% (Table 2).
For the a-amylase activity using the colorimetric
method with reading of absorbance at 540 nm and mea-
sured with a solution of ID-alG
at 41 mg/L on 30
batches, ID-alG
induced a decrease in the a-amylase
activity of 68.0 2.0% (Table 2).
Effect of ID-alG
on a fat-enriched-diet model
Food and drink intakes. The recording of food and
drink intakes during the 9 weeks of experiment are pre-
sented in Figs 1 and 2, respectively. No statistical analyse
was performed on these parameters because of the low
number of values per group (n= 3).
Nevertheless, the food intakes of the two groups con-
suming ID-alG
with the fat-enriched diet was always
higher than that of the positive control from the third
week but globally lower than that of the negative
Table 1. Composition of the standard and fat-enriched diets (%)
Standard diet
TD.94045
Fat-enriched diet
TD.06414
Casein 20.0 26.5
L-cystein 0.3 0.4
Corn starch 39.7
Maltodextrin 13.2 16.0
Sucrose 10.0 9.0
Bacon 31.0
Soya oil 7.0 3.0
Cellulose 5.0 6.55
Mineral mix, AIN-93 G-MX 3.5 4.8
Dialkaline, calcium
phosphate
0.34
Vitamin mix, AIN-93 G-VX 1.0 2.1
Choline bitartrate 0.25 0.3
TBHQ (antioxidant) 0.0014
Blue food colouring agent 0.01
Table 2. Effects of ID-alG
on lipase and a-amylase inhibition
activities (%) measured in vitro
Lipase activity Α-amylase activity
Inhibition activity (%) 71.0 2.0
a
68.0 2.0
a
a
Values are expressed as mean SEM on 30 batches.
EFFECT OF ID-ALG
ON WEIGHT MANAGEMENT
Copyright © 2011 John Wiley & Sons, Ltd. Phytother. Res. (2011)
control. In addition, the drink intakes of the two groups
consuming ID-alG
with the fat-enriched diet were
always lower than that of the negative control. Globally,
the three groups consuming the fat-enriched diet had an
equivalent drink intake except during the rst week of
the experiment.
Effect on body weight of rats under fat-enriched diet.
Figure 3 shows the body weight curves of rats fed with
a standard diet (negative control group) or fat-enriched
diet during the 9 weeks of the experiment and orally
treated daily with the seaweed extract ID-alG
at doses
of 40 and 400 mg/kg/day or the vehicle (positive control
group). The KruskalWallis test showed no signicant
difference between the mean body weights of rats of
the four experimental groups on D1 (H
(ddl=3)
= 0.28,
p= 0.96) and on D8 (H
(ddl=3)
= 2.98, p= 0.40). On the
other hand, at the end of the 9 weeks of experiment,
the KruskalWallis test showed a signicant difference
between the mean body weights of rats of the four
experimental groups on D64 (H
(ddl=3)
= 13.18, p= 0.004).
At the end of the experiment on D64, the mean body
weight (MBW) of rats was signicantly increased by the
fat-enriched diet (252.5 g 3.9 for the negative control
group versus 283.3 g 4.7 for the positive control group,
p= 0.004) and the oral consumption of ID-alG
induced
a signicant decrease of MBW under the fat-enriched
diet in comparison to the positive control: 264.0 g 3.3
for the dose of 40 mg/kg/day (p= 0.016) and 249.8 g 8.6
for the dose of 400 mg/kg/day (p= 0.025) (Table 3).
A statistical difference was observed between the
mean body weight gains (MBWG) of rats of the four
experimental groups between D8 and D64 according
to the KruskalWallis test (H
(ddl=3)
= 10.01, p= 0.02).
As presented in Table 3, the fat-enriched diet induced
a signicant increase of the MBWG of rats from
49 g 7.3 for the negative control group to 82.8 g 5.4
for the positive control group (p= 0.007). The oral
consumption of ID-alG
signicantly decreased the
MBWG of rats in comparison to the positive control
group in a dose-dependent manner. Between D8 and
D64 and in comparison to the positive control group,
the MBWG of rats was reduced by 22.0% (64.6g3.2;
p= 0.029) and by 31.8 % (56.5 g 9.3; p= 0.05) for the
two groups consuming the fat-enriched diet and orally
treated with ID-alG
at the doses of 40 and 400 mg/
kg/day, respectively. In addition, no statistical difference
was observed between the negative control group and
the two groups consuming the fat-enriched diet and
orally treated with ID-alG
at both doses of 40 and
400 mg/kg/day.
Effect on body fat mass of rats under the fat-enriched
diet. Table 3 shows the percentage of body fat mass
(BFM) of rats fed with a standard diet (negative control
group) or fat-enriched diet during the 9 weeks of the ex-
periment and orally treated daily with the seaweed ex-
tract ID-alG
at doses of 40 and 400 mg/kg/day or the
vehicle (positive control group). The KruskalWallis
test showed no signicant difference between the BFM
of rats of the four experimental groups before the start
of oral treatments on D0 (H
(ddl=3)
= 0.41, p= 0.94) but
a statistical difference was observed at the end of the
9 weeks of oral treatments on D64 (H
(ddl=3)
= 11.78,
p= 0.008). The BFM was statistically different between
the negative control (5.40% 0.18) and the positive
control (6.32% 0.14) groups (p= 0.006). As for the
MBW and the MBWG of rats, the BFM was signi-
cantly lower in the two groups fed with the fat-enriched
diet and orally treated daily with ID-alG
at both doses
than that of the positive control group: 5.70 % 0.06
(p= 0.005) and 5.12% 0.35 (p= 0.04) for the doses of
40 and 400 mg/kg/day, respectively. No statistical differ-
ence was observed between the mean BFM of rats of
the negative control group and the two groups fed with
the fat-enriched diet and orally treated with ID-alG
at both doses of 40 and 400 mg/kg/day (Table 3).
30
40
50
60
70
80
1 2 3 4 5 6 7 8 9
ID-alG™ 400 (FED)
ID-alG™ 40 (FED)
Positive control (FED)
Negative control (SD)
Food intake (g/kg body weight)
Time (weeks)
Figure 1. Evolution of weekly food intake of rats (g/kg body
weight) on a standard diet (SD) and fat-enriched diet (FED) during
the 9 weeks of the experiment and orally treated with ID-alG
at
both doses of 40 and 400 mg/kg/day and vehicle between weeks
2 and 9.
60
80
100
120
140
160
1 2 3 4 5 6 7 8 9
ID-alG™ 400 (FED)
ID-alG™ 40 (FED)
Positive control (FED)
Negative control (SD)
Drink intake (g/kg body weight)
Time (we eks)
Figure 2. Evolution of weekly drink intake of rats (g/kg body
weight) on a standard diet (SD) and fat-enriched diet (FED) during
the 9 weeks of the experiment and orally treated with ID-alG
at
both doses of 40 and 400 mg/kg/day and vehicle between weeks
2 and 9.
160
180
200
220
240
260
280
300
1 8 15 22 29 36 43 50 57 64
ID-alG™ 400 (FED)
ID-alG™ 40 (FED)
Positi ve control (FED)
Nega tive control (SD)
Body weight (g)
Time (days)
Figure 3. Evolution of body weight of rats (g) on a standard diet
(SD) and fat-enriched diet (FED) during the 9 weeks of the experi-
ment and orally treated with ID-alG
at both doses of 40 and
400 mg/kg and vehicle between Day 8 and Day 64.
K. TERPEND ET AL.
Copyright © 2011 John Wiley & Sons, Ltd. Phytother. Res. (2011)
Effect on lipidic parameters. Table 4 presents the evolu-
tion of triglyceride blood levels between D0 and D64.
The Kruskal-Wallis test showed no signicant difference
between the mean triglyceride blood levels of rats of the
four experimental groups on D0 (H
(ddl=3)
=0.01, p= 0.99)
but a signicant difference on D64 (H
(ddl=3)
= 10.37,
p= 0.016). At the dose of 40 mg/kg/day, ID-alG
did not
improve the triglyceride blood level in comparison to the
Positive control group. However, the highest dose of
400 mg/kg/day of ID-alG
induced a signicant decrease
in the triglyceride blood level in comparison to the positive
control group (0.52 g/L 0.07 vs. 1.06 g/L 0.21, p=0.01).
No statistical difference was observed between the
mean total cholesterol, LDL and HDL blood levels of
rats of the four experimental groups on D0 and at the
end of the treatment period on D64 (data not shown).
DISCUSSION
The present study was designed to determine the
chronic effects of orally administered ID-alG
, a sea-
weed extract of Ascophyllum nodosum, on the weight
management of rats receiving a fat-enriched diet for in-
ducing obesity. The comparison between the negative
control and the positive control groups showed clearly
the impact of the fat-enriched diet on the MBWG and
the percentage of BFM. The consumption of the fat-
enriched diet at 60.0% fat/kcal during 8 weeks induced
a signicant increase in the MBWG of 69.0% and in
the BFM of 17.0% in comparison with the standard diet
at 16.0% fat/kcal. Rats receiving the fat-enriched diet at
60.0% fat/kcal and orally treated with ID-alG
showed
signicantly lower MBWG and BFM in comparison to
the positive control group at both doses of 40 and
400 mg/kg/day of ID-alG
: the MBWG was reduced
by 22.0% and 31.8%, respectively, and the BFM was
reduced by 9.8% and 19.0%, respectively. Over the
same period, the MBWG and the BFM of rats receiving
the fat-enriched diet and orally treated with ID-alG
at
both doses of 40 and 400 mg/kg/day were statistically
equivalent to those of rats receiving the standard diet,
indicating that the oral consumption of ID-alG
seemed to neutralize the weight gain of rats induced
by a fat-enriched diet.
The oral administration of ID-alG
was associated
with a signicant reduction of the triglyceride blood
levels at the dose of 400 mg/kg/day, showing its potential
to improve triglyceride metabolism and to reduce risk
factors. Hepatic triglyceride accumulation from periph-
eral dietary sources and from endogenous de novo lipo-
genesis has been quantied in adult Sprague-Dawley
rats and shown that hepatic triglyceride accumulation
concentrations are acutely inuenced by dietary lipid
concentrations (Delgado et al., 2009). The results
observed on the inhibition of triglyceride blood levels
by ID-alG
are one promising key to help solve over-
weight problems, as shown in this rat study.
No effect was observed on the cholesterol level in the
female Sprague-Dawley rats, which could be due to the
rodent model used, as the main criteria of this study was
the fat absorption inducing triglycerides and fat mass.
Further investigations are essential to determine if
ID-alG
indeed has a direct (lipid metabolism) or an
indirect (weight loss) effect on the cholesterol prole,
ideally with further clinical trials in humans.
The benecial effect of ID-alG
observed on the
in vivo model on weight management could be linked
to its inhibitory properties of digestive enzymes such as
lipase and a-amylase. Preliminary results showed that
ID-alG
had an important inhibitory effect on the
enzymatic activities of lipase and a-amylase. However,
Table 3. Effects of oral treatments during 9 weeks (D1-D64) with ID-alG
at both doses of40 and 400 mg/kg/day and vehicle on body
weight, mean body weight gain (MBWG) and body fat mass (BFM) of rats (Mean SEM) on a fat-enriched diet (FED) or standard
diet (SD) during 8 weeks (D8-D64)
Treatment (n=6)
Dose
(mg/kg/day)
BW (g) MBWG (g) BFM (%)
Day 1 Day 8 Day 64 Day 1Day 8 Day 8Day 64 Day 0 Day 64
Negative control (SD) 185.3 3.8 203.5 6.3 252.5 3.9 +18.2 4.4 +49.0 7.3 1.70 0.20 5.40 0.18
Positive control (FED) 184.7 2.7 200.5 3.3 283.3 4.7
a
+15.8 3.3 +82.8 5.4
e
1.67 0.24 6.32 0.14
h
ID-alG
40 (FED) 40 185.2 1.9 200.7 2.4 264.0 3.3
b;c
+15.5 2.6 +64.6 3.2
f
1.72 0.13 5.70 0.06
i
ID-alG
400 (FED) 400 183.7 3.4 193.3 3.8 249.8 8.6
d
+9.7 3.6 +56.5 9.3
g
1.68 0.23 5.12 0.37
j
Values are expressed as mean SEM of six rats in each group.
BW:
a
p= 0.004 and
b
p= 0.025 compared with the negative control group on Day 64 using the MannWhitney U-test.
c
P= 0.016 and
d
P= 0.025 compared with positive control group on Day 64 using MannWhitney U-test.
MBWG:
e
p= 0.007 compared with the negative control group between Day 8 and Day 64 using the MannWhitney U-test.
f
p= 0.029 and
g
p= 0.05 compared with positive control group between Day 8 and Day 64 using MannWhitney U-test.
BFM:
h
p= 0.006 compared with the negative control group on Day 64 using the MannWhitney U-test..
i
p= 0.005 and
j
p= 0.04 compared
with the positive control group on Day 64 using the MannWhitney U-test.
Table 4. Effects of oral treatments during 9 weeks (D1-D64) with
ID-alG
at both doses of40 and 400 mg/kg/day and vehicle on
triglyceride blood levels of rats (mean SEM) on a fat-enriched
diet (FED) or standard diet (SD) during 8 weeks (D8D64)
Treatment
(n=6)
Dose
(mg/kg/day)
Triglyceride blood level (g/L)
Day 0 Day 64
Negative control (SD) 0.72 0.13 0.67 0.11
Positive control (FED) 0.71 0.11 1.060.21
ID-alG
40 (FED) 40 0.72 0.14 0.98 0.11
ID-alG
400 (FED) 400 0.75 0.18 0.52 0.07
a
Values are expressed as mean SEM of six rats in each group.
a
p= 0.01 compared with the positive control group on Day 64
using the MannWhitney U-test.
EFFECT OF ID-ALG
ON WEIGHT MANAGEMENT
Copyright © 2011 John Wiley & Sons, Ltd. Phytother. Res. (2011)
a dose-dependent investigation would be more appro-
priate and conducted to test this in vitro potential.
ID-alG
contains a level of tannins of 39% eq. phloro-
glucinol 1% (measured according to European
Pharmacopeia analytical method (Ph. Eur. 6.3, }2.8.14)
based on the complexation of the polyphenols with the
higher polymerization degree with powder and expressed
as phloroglucinol equivalent). These results are in accord-
ance with previous studies performed on Ascophylum
nodosum extracts showing enzymatic inhibitory activities
of a-glucosidase and a-amylase in correlation with the
phenolic components (Apostolidis and Lee, 2010). Marine
brown algae such as Ascophyllum nodosum, accumulate
polyphenols in polymeric form, i.e. phlorotannins (Shibata
et al., 2004; Audibert et al., 2010) and the specicity of the
seaweed extract of Ascophyllum nodosum,ID-alG
,isits
higher content of polyphenols in polymeric form, with
39.0% 1.0 of tannins. Polymers showed a strong
inhibitory activity against a-amylase, while oligomers had
a relatively weak effect suggesting that the inhibition of
a-amylase activity would probably depend on the degree
of polymerization (Lee et al., 2007). The polymerization
of polyphenols is also required for enhancement of
pancreatic lipase inhibition (Nakai et al. 2005).
Our results clearly demonstrate the benecial effects of
chronic oral administration of ID-alG
in high-fat-fed fe-
male Sprague-Drawley rats and they show that ID-alG
could be helpful to facilitate the inhibition of triglyceride
blood levels in situations of promoting weight loss and/or
prevention of weight gain. The specichighcontentoftan-
nins could explain its specic inhibitory activities on a-
amylase and lipase, leading to a lower absorption of lipids
and carbohydrates resulting from the diet. Further investi-
gations are essential to prove in vivo the relevant mechan-
ism of action involved for this ID-alG
effect on weight
management and body fat mass reduction. Moreover,
these in vivo results have already been conrmed in
humans in a monocentric, parallel, double-blind, rando-
mized and placebo controlled clinical trial made on 60
women, characterized with a mean age of 33 years old over
a period of 2 months (unpublished results from a clinical
study performed by BIO SERAE Laboratoires).
Acknowledgements
We would like to thank Mrs Stéphanie Daubie from ETAP Research
Centre, for her technical assistance in performing the in vivo study,
and Dr M.-C. Dederichs, Director of the Laboratory of Medical
Analyses Aubert in Vandœuvre-lès-Nancy, for performing the blood
lipidic dosages.
Conflict of Interest
The authors state there was no conict of interest.
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EFFECT OF ID-ALG
ON WEIGHT MANAGEMENT
Copyright © 2011 John Wiley & Sons, Ltd. Phytother. Res. (2011)
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... The rats obese or diabetic by feeding them with a daily food intake of high-fat diets, and depending only on the increase in their energy intake [10,13], in these rats fed with HFD, this was associated with a limited increase in body weight, compared to standard diet. However, in the present study, the rats reduced their food intake, which was possibly due to the low palatability of the high-fat diet given Feeding these rats with HFD significantly increased the serum triglyceride levels, compared to standard diet, as has been shown in different studies [10,13,14]. This effect was significantly reduced by supplementation with medium and high doses of Norwegian A. nodosum phytocomplex, in agreement with Terpend et al. [10]. ...
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The effects of certain tea components on the prevention of obesity in humans have recently been reported, although it is still unclear whether black tea consumption is beneficial. We obtained black tea extract (BTPE) consisting of polyphenols specific to black tea, and from it, prepared a polymerized polyphenol fraction (BTP). The effectiveness of oral administration of the BTPE was examined in in vitro and in vivo experiments. Effects of BTPE or BTP on pancreatic lipase activity were investigated in vitro. Male Wistar rats were administered an oral lipid emulsion containing BTPE at a concentration of 500 or 1000 mg/kg body weight and sequential plasma lipid levels were measured. Female C57BL/6N mice were fed a standard or high-fat diet supplemented with 1% or 5% (w/w) BTPE for 8 wk and changes in body weight were examined. BTP and BTPE inhibited pancreatic lipase activity with an IC(50) of 15.5 and 36.4 μg/mL in vitro, respectively. BTPE suppressed increases in rat plasma triglyceride levels in a dose-dependent manner after oral administration of a lipid emulsion. Furthermore, administration of the 5% BTPE suppressed increases in body weight (P < 0.05), parametrial adipose tissue mass, and liver lipid content (reduced to 56.9% and 81.7% of control mice, respectively, P < 0.05) in mice fed a high-fat diet. The BTPE may prevent diet-induced obesity by inhibiting intestinal lipid absorption. It was suggested that the major active component in the BTPE was BTP.
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The amounts and compositions of polyphenol in persimmon leaves and persimmon leaf tea were investigated. The predominant polyphenols in fresh leaves were water-soluble, and the contents reached a maximum (2.40% w/w) in June, and then gradually decreased. Separation of them followed by thiolytic degradation revealed that the major components were unique proanthocyanidin oligomers consisting of four heterogeneous extension units, including epigallocatechin-3-O-gallate. Persimmon leaf tea also contained similar proanthocyanidins with similar compositional units. Oral administration of starch with polyphenol concentrate of persimmon leaf tea resulted in a significant and dose-dependent decrease in the blood glucose level in Wistar rats. This effect is considered to be due to inhibition of pancreas alpha-amylase. These results indicate that persimmon leaf tea containing peculiar proanthocyanidins has a significant role in suppressing blood glucose elevation after starch intake, and that the best harvest time is June.
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Ascophyllum nodosum is a brown seaweed that grows abundantly in the Northeast coastal region. In this study, the potential of A. nodosum for type 2 diabetes management through antioxidant-mediated alpha-glucosidase and alpha-amylase inhibition was investigated. After the initial screening of 4 locally harvested seaweeds, A. nodosum was chosen for its highest phenolic content and was subjected to water extraction. Among extraction ratios of 50 g to 100 to 1000 mL at room temperature, 50 g/400 mL yielded the highest phenolic content of 4.5 mg/g wet weight. For evaluation of extraction temperature ranging from 20 to 80 degrees C, 50 g/400 mL was chosen as a minimum amount of extractant. Among temperatures studied, extraction at 80 degrees C resulted in the highest total phenolic contents (4.2 mg/g wet weight). All extracts had similar levels of antioxidant activity in the range of 60% to 70% in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The 80 degrees C extract had the highest alpha-glucosidase and alpha-amylase inhibitory activity with IC(50) of 0.24 and 1.34 microg phenolics, respectively, compared to the IC(50) of acarbose, reference inhibitor, being 0.37 and 0.68 microg. The results show that fresh A. nodosum has strong alpha-glucosidase and mild alpha-amylase inhibitory activities that correlated with phenolic contents. This study suggests a nutraceutical potential of A. nodosum based on phytochemical antioxidant and antihyperglycemia activities.
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Phenolic compounds are metabolites exhibited at high levels in Phaeophyceae. Although several studies have been conducted on total phenol contents, no one to our knowledge has dealt with the contents of phenolic compounds and antioxidant activities on purified fractions. The purpose of this study was the extraction and purification of phenolic compounds from the brown seaweed Ascophylllum nodosum, to determine both their distribution and their radical-scavenging activities, and to obtain a sufficiently purified oligophenolic fraction to perform an RP-HPLC analysis on molecules with a molecular weight (MW) < 2 kDa. Phenolic compounds were separated and purified by liquid-liquid extraction, tangential ultrafiltration and dialysis. Then, the contents of both phenolic compounds and radical-scavenging activities were measured by the Folin-Ciocalteu reagent, and DPPH and ABTS assays. NMR analysis was performed to validate the process. RP-HPLC with a C(18) column was performed on the oligophenolic fraction, using a novel method developed in this study. Seven fractions were obtained as a function of polarity and molecular weight. Among them, the fraction containing phenolic compounds with a MW ≥ 50 kDa appeared to be the most active, correlated with the content of phenolic compounds. This work constitutes a step forward in the separation and purification of bioactive phlorotannins and represents a prerequisite for further investigations into their structural characterisation and distribution in A. nodosum.
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The present study was to investigate in vitro alpha-glucosidase, pancreatic alpha-amylase and protein glycation inhibitory activities of nine edible plants. The results indicated that total phenolics, flavonoids, and condensed tannins of nine edible plants showed marked variations, ranging from 12.2 to 80.1 mg gallic acid equivalent/g extract, 2.34 to 13.65 mg quercetin equivalent/g extract, and 97.2 to 460.1 mg catechin equivalent/g extract, respectively. Our findings showed that grape seed, Cat's whiskers and Sweetleaf extract were the most effective pancreatic alpha-amylase, intestinal maltase, and sucrase inhibitor with IC(50) values of 0.29 +/- 0.01 mg/ml, 0.97 +/- 0.10 mg/ml and 0.86 +/- 0.01 mg/ml, respectively. All extracts (1 mg/ml) markedly inhibited the glycation of bovine serum albumin in fructose-mediated non-enzyme glycation by 50-30% at week 1. It was found that Pennywort maintained the high percentage inhibition among those of the extracts during the 4 weeks of experiment. These edible plants may be used for controlling blood glucose level and prevention of the development of type 2 diabetes.
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Plenty of polyphenols, i.e. phenolic acids and flavonoids, were found in longan flower water extract (LFWE) through spectrophotometric and HPLC analyses. Antiobesity and hypolipidemic effects of polyphenol-rich longan flower water extract (LFWE) were investigated in this study. Eight male rats per group were assigned randomly to one of the following dietary groups: (1) normal-caloric diet and pure water (NCD + NDW); (2) hypercaloric diet and pure water (HCD + NDW); (3) HCD and 1.25% (w/v) LFWE (HCD + 1.25% LFWE); (4) HCD and 2.5% (w/v) LFWE (HCD + 2.5% LFWE) for 9 weeks. Body weight, size of epididymal fat, serum triglyceride level and atherogenic index, and hepatic lipids were decreased (p < 0.05) in HCD rats by drinking 2.5% LFWE which may result from downregulated (p < 0.05) pancreatic lipase activity, and sterol regulatory element binding protein-1c (SREBP-1c) and fatty acid synthase (FAS) gene expressions, as well as upregulated (p < 0.05) LDL receptor (LDLR) and peroxisome proliferator-activated-receptor-alpha (PPAR-alpha) gene expressions, and also increased (p < 0.05) fecal triglyceride excretions. Therefore, polyphenol-rich LFWE indeed characterizes antiobesity and hypolipidemic effects in vivo.
Article
This study was designed to investigate whether diphlorethohydroxycarmalol (DPHC) may inhibit alpha-glucosidase and alpha-amylase activities, and alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. DPHC isolated from Ishige okamurae, a brown algae, evidenced prominent inhibitory effect against alpha-glucosidase and alpha-amylase. The IC(50) values of DPHC against alpha-glucosidase and alpha-amylase were 0.16 and 0.53 mM, respectively, which evidenced the higher activities than that of acarbose. DPHC did not exert any cytotoxic effect in human umbilical vein endothelial cells (HUVECs) at various concentrations (from 0.49 to 3.91 mM). The increase of postprandial blood glucose levels were significantly suppressed in the DPHC-administered group than those in the streptozotocin-induced diabetic or normal mice. Moreover, the area under curve (AUC) was significantly reduced via DPHC administration (2022 versus 2210 mmol x min/l) in the diabetic mice as well as it delays absorption of dietary carbohydrates. Therefore, these result indicated that DPHC might be a potent inhibitor for alpha-glucosidase and alpha-amylase.
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Managed care initiatives to reduce cardiovascular disease (CVD) risk have, to date, focused almost exclusively on statins, which are primarily low-density lipoprotein cholesterol-lowering agents and have limited effects on triglycerides and high-density lipoprotein (HDL) cholesterol at commonly used doses. Significant residual CVD risk (ie, risk of recurrent CVD events) remains after treatment with statins and may stem, at least partially, from low HDL cholesterol and/or elevated triglycerides. Consequently, national treatment guidelines suggest that combination therapy may be necessary to address multiple lipid targets and adding niacin or a fibrate to a statin is a strategy to be considered. Recent clinical trial evidence has demonstrated the efficacy of niacin/statin and fenofibric acid/statin combination therapies in treating multiple lipid abnormalities.