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Avenanthramide supplementation attenuates exercise-induced inflammation in postmenopausal women


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During aging, chronic systemic inflammation increases in prevalence and antioxidant balance shifts in favor of oxidant generation. Avenanthramide (AVA) is a group of oat phenolics that have shown anti-inflammatory and antioxidant capability. The present study investigated whether dietary supplementation of avenanthramides (AVA) in oats would increase antioxidant protection and reduce inflammation after a bout of downhill walking (DW) in postmenopausal women. Women at age of 50-80 years (N = 16) were randomly divided into two groups in a double-blinded fashion, receiving two cookies made of oat flour providing 9.2 mg AVA or 0.4 mg AVA (control, C) each day for 8 weeks. Before and after the dietary regimen, each group of subjects walked downhill on a treadmill (-9% grade) for 4 bouts of 15 minutes at a speed of 4.0 km/h with 5 minutes rest between sessions. Blood samples were collected at rest, 24 h post-DW, and 48 h post-DW pre- and post-supplementation. Both DW sessions increased plasma creatine kinase activity (P < 0.05). Before supplementation, in vitro neutrophil respiratory burst (NRB) activity was increased at 24 h post-DW (P < 0.05) and C-reactive protein (CRP) was increased 48 h post-DW (P < 0.05). AVA supplementation decreased DW-induced NRB at 24 h (P < 0.05) and CRP level 48 h (P < 0.05). Plasma interleukin (IL)-1beta concentration and mononuclear cell nuclear factor (NF) kappaB binding were suppressed at rest and during post-DW period in AVA but not C group (P < 0.05). Plasma total antioxidant capacity (P < 0.05) and erythrocyte superoxide dismutase activity were increased in AVA vs. C (P < 0.05), whereas glutathione redox status was elevated 48 h post-DW but not affected by AVA. Thus, chronic AVA supplementation decreased systemic and DW-induced inflammation and increased blood-borne antioxidant defense in postmenopausal women.
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R E S E A R C H Open Access
Avenanthramide supplementation attenuates
exercise-induced inflammation in
postmenopausal women
Ryan Koenig
, Jonathan R Dickman
, Chounghun Kang
, Tianou Zhang
, Yi-Fang Chu
and Li Li Ji
During aging, chronic systemic inflammation increases in prevalence and antioxidant balance shifts in favor of
oxidant generation. Avenanthramide (AVA) is a group of oat phenolics that have shown anti-inflammatory and
antioxidant capability. The present study investigated whether dietary supplementation of avenanthramides (AVA)
in oats would increase antioxidant protection and reduce inflammation after a bout of downhill walking (DW) in
postmenopausal women. Women at age of 5080 years (N = 16) were randomly divided into two groups in a
double-blinded fashion, receiving two cookies made of oat flour providing 9.2 mg AVA or 0.4 mg AVA (control, C)
each day for 8 weeks. Before and after the dietary regimen, each group of subjects walked downhill on a treadmill
(9% grade) for 4 bouts of 15 minutes at a speed of 4.0 km/h with 5 minutes rest between sessions. Blood samples
were collected at rest, 24 h post-DW, and 48 h post-DW pre- and post-supplementation. Both DW sessions
increased plasma creatine kinase activity (P < 0.05). Before supplementation, in vitro neutrophil respiratory burst
(NRB) activity was increased at 24 h post-DW (P < 0.05) and C-reactive protein (CRP) was increased 48 h post-DW
(P < 0.05). AVA supplementation decreased DW-induced NRB at 24 h (P < 0.05) and CRP level 48 h (P < 0.05). Plasma
interleukin (IL)-1βconcentration and mononuclear cell nuclear factor (NF) κB binding were suppressed at rest and
during post-DW period in AVA but not C group (P < 0.05). Plasma total antioxidant capacity (P < 0.05) and
erythrocyte superoxide dismutase activity were increased in AVA vs. C (P < 0.05), whereas glutathione redox status
was elevated 48 h post-DW but not affected by AVA. Thus, chronic AVA supplementation decreased systemic and
DW-induced inflammation and increased blood-borne antioxidant defense in postmenopausal women.
The skeletal muscle of aged individuals decreases muscle
mass, force generation and metabolic functions known as
sarcopenia. Recent research points to a strong link be-
tween aging and inflammation [1,2]. So many diseases
have been identified to have an etiological origin of in-
flammation that the term inflammaginghas been coined
[3-6]. Therefore, developing strategies to prevent and re-
duce inflammation in the aging population has become a
priority in gerontological research in recent years.
The increase in inflammation during aging has been
linked to increased nuclear factor (NF) κB binding to
DNA in many organs and tissues, as well as several types
of blood borne cells [7]. NFκB is sensitive to oxidative
stress and a variety of other stimuli and is responsible
for the regulation of the transcription of a variety of
gene targets, including pro-inflammatory cytokines such
as interleukin (IL)-1, 6 and tumor necrosis factor (TNF)-
α[8]. Aged rats and mice displayed increased nuclear
NFκB binding activity in several major organs studied,
whereas no increase in cytoplasmic NFκB was observed
[9]. IL-1 and 6 gene expression in the T cells of older hu-
man subjects was elevated compared with younger
counterparts with or without NFκB induction, indicating
aging is associated with immune dysregulation resulting
in a pro-inflammatory state [10].
In women the phenomenon of menopause results in a
lack of production of estrogen, which adds complexity
to the aging milieu. Estrogens function as antioxidants,
* Correspondence:
Department of Kinesiology, University of WisconsinMadison, Madison,
WI 53706, USA
Laboratory of Physiological Hygiene and Exercise Science, University of
Minnesota, 1900 University Avenue, Minneapolis, MN 55455, USA
Full list of author information is available at the end of the article
© 2014 Koenig et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver ( applies to the data made available in this article,
unless otherwise stated.
Koenig et al. Nutrition Journal 2014, 13:21
and their absence in postmenopausal women could con-
tribute to an increased susceptibility to oxidative stress
[11]. Estrogen was recently shown to up-regulate anti-
oxidant enzymes via mitogen activated protein kinase
(MAPK) and NFκB pathways [12]. In addition estrogens
may function to stabilize cell membranes and to regulate
cell signaling through the binding to estrogen receptors
[13]. These mechanisms are thought to provide import-
ant protection from muscle damage to women following
a bout of unaccustomed exercise. Indeed, postmeno-
pausal women exhibited increased serum creatine kinase
(CK) and lactate dehydrogenase (LDH) as well as in-
creased mRNA expression of pro-inflammatory cyto-
kines following strenuous eccentric exercise compared
to their counterparts with hormone therapy [14].
Downhill walking is a muscular activity that involves
lengthening or eccentric contraction (EC) and breaks
weaken myofibrils and activate proteases and lipases,
followed by immunological responses such as infiltration
of neutrophils, free radical generation and expression of
pro-inflammatory cytokines and chemokines [15]. NFκB
activation escalates the process and provokes systemic
inflammation that could have broad health outcomes
such as muscle pain, chronic inflammation (rheuma-
toid), leading to underperformance and fear of participa-
tion in exercise and sports. However, recent research
have shown pharmacological treatments of EC-induced
inflammation such as NSAID might interrupt normal
healing process and large doses supplementation of anti-
oxidants of pharmaceutical source can be more detri-
mental than beneficial as it interferes with intrinsic
adaptive responses and sometimes takes away the benefit
of exercise [16,17]. Thus, seeking phytochemicals dem-
onstrating antioxidant and anti-inflammatory properties
for daily dietary supplements is desirable.
Oat (Avena sativa), although consumed in consider-
ably lower quantities worldwide than wheat and rice, has
a highly edible quality and contains high antioxidants
such as tocopherols, tocotrienols, and flavonoids [18]. In
addition, oat contains a unique group of approximately
40 different types of avenanthramides (AVA) that consist
of an anthranilic acid derivative and a hydroxycinnamic
acid derivative linked by a pseudo- peptide bond [19]. Of
all the AVA that have been identified, three stand out
due to their abundance and have been labeled as AVA-
A, B, and C, which differ by a single moiety on the
hydroxycinnamic acid ring. All three AVA of interest
showed antioxidant activity with AVA-C being the most
potent [20]. Additional studies performed have shown
that AVA have the anti-inflammatory and anti-
atherogenic effects of decreasing monocyte adhesion to
human aortic endothelial cells (HAEC), as well as their
expression of adhesion molecules and pro-inflammatory
cytokines [21]. AVA-C displayed further antiatherogenic
potential by inhibiting vascular smooth muscle cell
(SMC) proliferation and enhancing nitric oxide produc-
tion in both SMC and HAEC in parallel with the up-
regulation of mRNA expression of endothelial nitric
oxide synthase [22]. These effects were shown to be de-
rived from decreased NFκB activity [23].
The antioxidant, anti-inflammatory, and NFκB inhibi-
tory properties of AVA make it a candidate for supple-
mentation in the cause of decreasing inflammation and
muscle damage in post-menopausal women. Thus, the
present study was designed to test the anti-inflammatory
and antioxidant capability of AVA in postmenopausal
women. We hypothesize that AVA supplementation
would increase plasma antioxidant defense, inhibit
NFκB-DNA binding in the mononuclear cells and de-
crease DW-induced systemic inflammation.
Materials and methods
A. Subjects
Older women aged 5080 years were recruited from the
Madison, Wisconsin, community or from faculty and
staff of the University of Wisconsin-Madison. The re-
cruitment procedure and study conducts were approved
by the Health Science Institutional Review Board for
Human Subjects of UW-Madison. The subjects were
randomly assigned to one of two groups (N = 8 per
group) receiving a high dose of AVA supplementation in
the diet, or receiving a low dose of AVA present in nor-
mal oats, serving as Control. Other than this difference,
the groups were treated exactly the same in a double-
blind fashion.
All participants gave informed consent before enrol-
ling in the study. They also completed a Health History
Survey to ensure that they were eligible for the study
and healthy enough to exercise. Criteria for exclusion
from the study were smoking or other tobacco use,
drinking alcohol in excess of 5 drinks per week, use of
dietary antioxidants, blood pressure medication, non-
steroidal anti-inflammatory drugs (NSAIDs) and antico-
agulants or antidiabetic or hypoglycemic drugs.
B. Dietary supplementation
Because the goal of the study is to study the biological
efficacy of AVA, we employed a dietary regimen wherein
both groups of subjects were supplemented with oats,
which differed only in AVA concentration but processed
identical nutritional and antioxidant contents (see
below). Both dietary groups of subjects received cookies
made with oat samples with standardized AVA concen-
tration provided courtesy of Ceapro Inc. (Edmonton,
AB, Canada). AVA concentrations were verified by high-
performance liquid chromatography (HPLC) in our la-
boratory. The high-AVA oat flour contained 190 mg/kg,
and the Control group flour contained 8 mg/kg, the
Koenig et al. Nutrition Journal 2014, 13:21 Page 2 of 11
lowest AVA concentration among all oat lines available.
The recipe for each type of cookie was identical except
in the type of flour used. Each cookie contained 30 g
flour (high- or low-AVA), 5.91 mL unsweetened apple
sauce (Surefine), 12.32 mL artificial sweetener (Natra-
taste Gold), 0.616 mL baking soda, and 0.0308 mL table
salt. They were baked in a low temperature oven (121°C)
for 15 minutes to ensure that AVA was not broken down
or produced by the oat during the process. AVA concen-
tration in the high-AVA cookies was 4.6 mg/cookie
(9.2 mg/day), and it was 0.2 mg/cookie (0.4 mg/day) in
the control cookies. Each cookie provided 125 kilocalo-
ries (250 kcal/day) regardless of group.
Supplementation began on the evening of the second
study visit following the third blood draw and ended on
the evening of the third study visit following the fifth
blood draw (see below). Subjects were furnished with
cookies and instructed to consume two per day: one in
the morning with breakfast and one in the evening with
C. Study visits
A total of six visits were required for each subject follow-
ing recruitment and consenting. There were three pre-
supplementation visits and three post-supplementation
visits identical to the pre-supplementation visits. The first
visit of each trio consisted of completion of the Inter-
national Physical Activity Questionnaire (IPAQ) and
health history questionnaire, downhill walking (DW), and
a blood draw. The second and third visit occurred 24 hours
after the first and consisted of a single blood draw. The
pre-supplementation and post-supplementation visits
were separated by 8 weeks of dietary supplementation
regimen as described above.
D. Downhill walking
DW was performed on a treadmill in the UW Biodynamics
Laboratory. Each of the 2 DW sessions consisted of 4 bouts
of 15 minutes of treadmill walking separated by 3 sessions
of 5 minutes of quiet rest. The treadmill grade was set
at 9% and the speed to 4.0 km/h. Heart rate was re-
corded every 5 minutes using a heart rate monitor.
E. Blood sample collection and preparation
Mixed venous blood was drawn from an antecubital vein
into 4 EDTA-coated Vacutainer tubes (7 mL each, Fisher
Scientific). Whole blood was placed on ice and then im-
mediately centrifuged at 500 × gat 4 degrees C for use in
the glutathione assay (see below) or gently pipetted over
two layers (3 ml of each) of density gradient (Histopaque
and Ficoll-Paque) for isolation of blood cells. After centri-
fugation at 500 × gfor 30 minutes at 20°C, plasma was re-
moved by aspiration and frozen at 80°C. A band of
monocytes was then removed by aspiration, washed with
phosphate buffered saline (PBS), and frozen at 80°C. Next,
the remaining fluid (not packed erythrocytes) was removed
and washed with ice cold PBS to attain neutrophils. Any
erythrocytes contaminating the sample were lysed with the
addition of nanopure water. After gentle inversion, tonicity
was restored by the addition of 3% NaCl. After centrifuga-
tion at 900 × gfor 5 minutes at 4°C, the neutrophil pellet
was resuspended in Hanks balanced salt solution (HBSS)
and the cells counted by microscope and hemacytometer
and diluted to 1.5 × 10
cells/mL for immediate analysis of
respiratory burst (see below). Packed erythrocytes were re-
moved and stored immediately at 80°C.
F. Biological measurements
Enzyme-linked immunosorbent assay (ELISA) kits
(eBioscience, Read-Set-Go! ELISA, San Diego, CA) were
used to test for the plasma concentrations of interleukin
(IL)-1β, IL-6, tumor necrosis factor (TNF)-α,andC-
reactive protein (CRP) per manufacturers instruction. All
samples were measured in duplicate using 96-well plates
coated with capture antibody. Following sample addition,
detection antibody, avidin horse radish peroxidase, and
enzyme substrate were added in succession with each step
separated by room-temperature incubation and thorough
washing with a PBS-Tween 20 wash buffer. Absorption at
525 nm was measured on a plate reader (Spectra MAx
340, Molecular Devices) and used to determine plasma
concentration from a standard curve generated using re-
combinant standards provided by the manufacturer.
NFκB binding to DNA was measured by ELISA in nuclear
extracts of mononuclear cells. The assay principle is as
above; however, only p65 bound to DNA was detected. Nu-
clear extraction was conducted according to manufacturers
instructions (Millipore Nuclear Extraction Kit). Manufac-
turers instructions were followed for the ELISA process,
which utilized an antibody against p65 (eBioscience
InstantOne ELISA). Samples were scanned using a
luminometer (Turner Biosystems #2030-000).
a. Plasma glutathione Glutathione concentrations were
measured by HPLC based on the method described by Ji
and Fu [24]. Both GSH and GSSG were detected, and the
ratio of GSH:GSSG calculated. This assay was performed
on plasma separated from a blood sample that was kept
on ice and centrifuged at 4°C immediately upon being
drawn. 250 μL of plasma was transferred to a tube con-
taining 10 μL of 0.4 mmol/L iodoacetic acid and ex-
cess sodium bicarbonate. After incubation at room
temperature for 1 hour, 2 μL of 2,4-dinitrofluorobenzene
(Sangers reagent, Sigma Chemical, St. Louis, MO) was
added, and the samples were kept in the dark for 28 hours
before the HPLC detection. Concentrations of GSH and
Koenig et al. Nutrition Journal 2014, 13:21 Page 3 of 11
GSSG were determined using a Shimadzu UVVIS de-
tector at 365 nm wavelength and quantified with standard
curves generated using GSH and GSSG standards.
b. Avenanthramide concentration Cookie AVA concen-
trations were measured using HPLC. The method of Chen
et al. [25] was modified for use on homogenized cookies.
To 200 μl of sample, 20 μl of vitamin C-EDTA was added.
Then 500 μl of 100% acetonitrile (ACN) was added to the
tubes. After 5 minutes, the samples were centrifuged at
15000 × gfor 5 min. The supernatant, which contained
the AVA, was removed, and the solvent was evaporated by
motorized vacuum pump (Fisher Scientific) at a pressure
of approximately 200 mm Hg for approximately 5 minutes.
The residue was reconstituted in 200 μlofHPLCaqueous
solvent. Again the samples were centrifuged at 15000 × g
for 5 min. The supernatant, which contained the AVA,
was removed, and the solvent was evaporated by motor-
ized vacuum pump (Fisher Scientific) at a pressure of ap-
proximately 200 mm Hg for approximately 5 minutes.
The residue was reconstituted in 200 μLofHPLCaqueous
solvent. Again the samples were centrifuged at 15000 × g
for 5 min. All samples were analyzed for AVA concentra-
tion with a procedure based on Milbury [26] on a dual
pump Shimadzu HPLC system with a UVVIS spectro-
photometric detector, a Supelco C18 column with inline
guard column. Absorption at 330 nm was tracked by
Shimadzu EZStart 7.2.1 software.
3. Neutrophil respiratory burst (NRB)
Neutrophils diluted in HBSS to 1.5 × 10
cells/mL were
assayed for respiratory burst activity by luminometer
using a procedure according to Benbarek et al. [27] with
modifications. Neutrophils were incubated with luminol
(Sigma, MO) for 5 minutes at 37°C in a shaking water
bath. Three concentrations of phorbol myristate acetate
(PMA) were used to evaluate the effects of maximal,
moderate, and minimal stimulation of the cells. The
highest concentration was 160 μmol/L, the middle con-
centration was 16 μmol/L, and the low concentration
was 1.6 μmol/L. A total of 1 × 10
neutrophils were used
in each trial. The respiratory burst chemiluminescence
was tracked for 30 minutes by luminometer (Turner
Biosystems) with 10 measurements in one second of in-
dividual samples every 2.5 minutes. A cell-free blank
containing equal volume of HBSS received luminol and
maximal PMA concentration in order to measure
chemiluminescence not associated with cellular activity.
The mean of 10 measurements at each time point was
calculated and the time course of the respiratory burst
plotted. Area under curve was calculated by the trapez-
oidal rule and used as a measure of total respiratory
burst activity.
4. Spectrophotometric assays
a. Plasma total antioxidant capacity Plasma total
antioxidant capacity (TAC) was measured by spectro-
photometer by monitoring the attenuation of 2,2-azinobis-
3-ethylbenzothiazoline-6-sulfonic acid (ABTS) oxidation at
734 nm according to Re et al. [28]. A solution of 7 mmol/L
ABTS and 2.45 mmol/L aluminum potassium sulfate (APS)
was made immediately before the conducting of the assay
and kept in the dark. An aliquot of 100 μLplasmawas
added to a final volume of 1 mL with ABTS/APS solution.
The cuvette was mixed by inversion and then incubated at
37°C for 5 minutes. The cuvettes were then read against
a Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carbox-
ylic acid) standard curve using a spectrophotometer
(Shimadzu UV160).
b. Plasma creatine kinase Plasma ceatine kinase (CK)
activity was measured as a marker of eccentric muscle
damage according to the procedure of Tanzer and Gil-
varg [29]. The CK reaction was coupled to NADH con-
version to NAD by lactate dehydrogenase (LDH), which,
along with pyruvate kinase (PK), phosphoenol pyruvate
(PEP), and NADH, were present in the reaction mixture.
The decrease in NADH concentration was tracked using
a spectrophotometer (Shimadzu UV160).
c. Erythrocyte superoxide dismutase Erythrocyte super-
oxide dismutase (SOD) activity was measured by spec-
trophotometrically by tracking the decrease in auto-
oxidation of epinephrine to adrenochrome according to
Sun and Zigman [30]. Epinephrine autoxidation rate was
measured at 320 nm for 3 minutes in the presence of an
aliquot of erythrocyte lysate. The slope of the linear por-
tion of the absorption graph was used to determine SOD
activity by determining the percent inhibition of epi-
nephrine autoxidation via comparison to the blank.
Activity was normalized to hemoglobin concentration.
d. Erythrocyte glutathione peroxidase Erythrocyte gluta-
thione peroxidase (GPx) activity was measured by moni-
toring the change in NADPH concentration in a system
with excess GSH and glutathione reductase (GR) in
the presence of H
[24]. Activity was normalized to
hemoglobin concentration.
Erythrocyte hemoglobin was measured using Drabkins
reagent (potassium ferricyanide and potassium cyanide
in sodium bicarbonate), which binds hemoglobin to
cause a shift in maximal absorbance, which can be mea-
sured by the spectrophotometer [31].
G. Statistical analysis
Data were shown as mean ± SEM and analyzed using the
Planned Comparison method. A three-way repeated mea-
sures ANOVA was conducted using R (version 2.14.1)
Koenig et al. Nutrition Journal 2014, 13:21 Page 4 of 11
statistical software. The three main factors are (a) post- vs.
pre-AVA supplementation, (b) timing with respect to DW
test (rest vs. 24 h post-DW vs. 48 h post-DW), and (c)
high-AVA vs. Control supplementation. The standard
error of estimate of the ANOVA was used to complete a
priori planned comparisons. Significance for each com-
parison was set at P< 0.00455, which is the quotient of
0.05 divided across the 11 comparisons.
A. Participant data
The age, height, weight, and body mass index (BMI) of
the study participants are displayed in Table 1. There
were no significant differences between groups for any
of the parameters measured. Body weight and BMI were
unchanged following dietary supplementation.
B. Muscle damage caused by DW
Plasma CK activity was significantly elevated 24 h after
DW both before and after the dietary supplementation
regimen (P< 0.05; Figure 1). CK activity was not differ-
ent 48 h after DW compared to resting levels in both
groups. No difference was observed between AVA and
control across all groups.
C. Inflammatory markers
In the current study inflammatory responses to DW by
older women subjects were assessed by several bio-
markers including neutrophil respiratory burst (NRB)
activity in vitro, plasma CRP concentration and pro-
inflammatory cytokine levels. NRB activity increased sig-
nificantly 24 h after DW before supplementation (P<
0.05; Figure 2). This post -DW elevation of NRB activity
maintained in Control group after 8 week dietary regi-
men, but was abolished in the high-AVA supplemented
group (P< 0.05).
Plasma level of CRP was not different between rest and
24 h post-DW either before or after the 8 week supple-
mentation, but increased significantly 48 h after DW prior
to supplementation (P< 0.05; Figure 3). Following supple-
mentation, plasma CRP level was elevated 48 h post-DW
only in Control group but not in AVA group (P<0.05).
Plasma IL-1βconcentration was not altered by DW
prior to dietary supplementation (Figure 4). Following 8
wk of high-AVA supplementation, IL-1βlevel at rest and
24 h post-DW was decreased by nearly 50% in the high-
AVA group compared to their Control counterparts (P<
0.05). This difference vanished at 48 h post-DW.
We measured plasma concentration of two other pro-
inflammatory cytokines, TNF-αand IL-6. TNF-αlevels
were not affected by DW before or after dietary supple-
mentation regimen, but showed a strong trend to de-
crease (0.05 < P < 0.1) after supplementation (data not
shown). IL-6 levels were not affected by DW or AVA
supplementation (data not shown).
DW did not significantly affect monocyte NFκB bind-
ing activity before dietary supplementation (Figure 5).
After supplementation NFκB binding was lower in AVA
vs. Control at rest as well as 24 and 48 h post-DW (P<
D. Antioxidant defense
Plasma TAC did not change significantly in response to
DW either before or after dietary oat supplementation,
however dietary supplementation regimen resulted in a
significant increase in TAC regardless of exercise status
or dietary AVA concentration (P< 0.05; Figure 6).
Erythrocyte SOD activity was unchanged with DW be-
fore the dietary supplementation regimen (Table 2). Fol-
lowing supplementation, SOD activity was significantly
greater in high AVA compared to Control group 48 h after
DW (P< 0.05, interaction). Erythrocyte GPx activity was
not altered by DW but showed a trend toward a lower
level in high-AVA vs. Control at Rest (P < 0.1, interaction).
Plasma GSH concentration was not significantly altered
by DW or dietary supplementation (Table 2). Plasma
GSSG concentration increased significantly (P< 0.05) 24 h
after DW and returned to baseline levels at 48 h both be-
fore and after supplementation. Change in GSSG was not
affected by AVA content in the diet. Plasma GSH:GSSG
ratio did not change at 24 h but was significantly increased
48 h post-DW vs. Rest both before and after dietary sup-
plementation (P< 0.05). No difference between AVA and
Control groups was observed.
In the present study, DW resulted in a significant,
though modest, increase in CK activity after 24 h indi-
cating that the DW protocol was sufficient to elicit
muscle damage among older womon subjects. The re-
peated eccentric contractions of DW might have caused
sarcomere stretching and membrane damage, leading to
Table 1 Characteristics of postmenopausal participants
Pre-Supplementation Post-Supplementation
Age (y) Height (m) Body Weight (kg) BMI Body Weight (kg) BMI
Control 60.125 ± 2.20 1.48 ± 0.025 57.50 ± 2.42 26.40 ± 1.59 57.65 ± 2.53 26.42 ± 1.61
AVA 59.000 ± 2.25 1.45 ± 0.051 60.45 ± 2.66 29.01 ± 1.27 59.91 ± 2.69 28.74 ± 1.39
Note: Data are mean ±SEM. AVA, avananthramide. BMI, body mass index defined by the ratio of body weight (kg) divided by height (meter)
Koenig et al. Nutrition Journal 2014, 13:21 Page 5 of 11
the escape of sarcoplasmic constituents such as CK to
the circulation. AVA supplementation did not affect the
extent of muscle damage due to DW, as the CK re-
sponse was unchanged after supplementation.
Previous studies have shown that a single bout of un-
accustomed eccentric exercise can lead to a protective
effect whereupon a second bout of eccentric exercise
may result in less muscle damage [32-34]. This effect
was not observed in this study possibly because the
8 week period between DW sessions was a sufficiently
long washout period and the DW protocol was mild
providing relatively small stimulus to the muscles in-
volved. Furthermore, postmenopausal women lack estro-
gen, which may provide membrane stability by
intercalating among plasma membrane phospholipids.
Therefore, the skeletal muscle of postmenopausal
women may be more prone to DW-induced damage
compared to younger subjects [13].
Figure 1 Plasma CK activity in postmenopausal women in response to downhill walking (DW). Data are mean ± SEM (N = 8). * P< 0.05,
24 h post-DW vs. Rest.
Figure 2 Neutrophil respiratory burst activity in postmenopausal women in response to DW. Data are mean ± SEM (N = 8), normalized to
Pre-Supplementation Rest value. * P< 0.05, 24 h vs. Rest. § P< 0.05, AVA vs. Control in 24 h post-DW.
Koenig et al. Nutrition Journal 2014, 13:21 Page 6 of 11
AVA supplementation reduced plasma inflammatory
The local response to eccentric contraction-induced
muscle damage is the triggering of inflammation [35]. A
major part of the muscle repair process is the arrival and
infiltration of neutrophils at the site of damage followed
by phagocytosis. During this process, NADPH oxidase
activity increases in a respiratory burst to convert O
superoxide radical and cause oxidative damage [36]. In
the current study we did not obtain muscle biopsy sam-
ples to test this scenario, however, concomitant with the
increase in CK 24 h post-DW, NRB increased signifi-
cantly in circulating neutrophils (Figure 2). This finding
suggests that DW-associated muscle damage might have
stimulated either receptor binding or NADPH oxidase
activity, or both of the circulating neutrophils.
After 8 weeks of dietary oat supplementation, DW
triggered a NRB level at 24 h in the Control group, simi-
lar to the response seen prior to the dietary regimen.
However, high-AVA supplementation resulted in a pro-
tection against this response. In a previous study, Brickson
et al. [37] showed in a rabbit muscle stretch injury
Figure 3 Plasma C-reactive protein (CRP) concentrations in postmenopausal women in response to DW. Data are mean ± SEM (N = 8).
*P< 0.05, 48 h post-DW vs. Rest. § P < 0.05, AVA vs. Control in 48 h post-DW.
Figure 4 Plasma interleukin (IL)-1βconcentrations in young women in response to DW. Data are mean ± SEM (N = 8). § P< 0.05, AVA vs.
Control in Rest and 24 h post-DW.
Koenig et al. Nutrition Journal 2014, 13:21 Page 7 of 11
model that M1/70 antibody could block the iC3b do-
main of neutrophil receptors for respiratory burst with-
out affecting its adhesive effect. Previous work
conducted in HAEC demonstrated that AVA was able to
inhibit both adhesion and inflammatory cytokine pro-
ductions [38]. Our data were the first time to show that
AVA could suppress neutrophil respiratory burst activity
in human in response to physical stress and thus sup-
port the notion that AVA is a potent anti-inflammatory
A key step for the signal transduction of mononuclear
cells is NFκB activation [39,40]. Peripheral blood mono-
nuclear cells isolated from patients with certain inflam-
matory diseases and pathogenesis showed increased
Figure 5 Mononuclear cell NFκB binding activity in postmenopausal women in response to DW. Data are mean ± SEM (N = 8), normalized
to Pre-Supplementation Rest value. § P< 0.05, AVA vs. Control.
Figure 6 Plasma total antioxidant capacity (TAC) in postmenopausal women. Data are mean ± SEM (N = 8). + P< 0.05, Post- vs. Pre-
supplementation regardless of time or AVA treatment.
Koenig et al. Nutrition Journal 2014, 13:21 Page 8 of 11
NFκB binding. Because previous studies showed that
AVA could block NFκB signaling in vitro [38,41], we
measured NFκB binding to DNA in the nuclear extracts
of mononuclear cells ex vivo. We found that older
women receiving 8 weeks of high-AVA diet showed sig-
nificantly reduced NFκB binding in mononuclear cells
compared to those who received low-AVA control diet
both at rest and during the two day post-DW recovery
period (Figure 5). These effects may be of particular im-
portance in postmenopausal women, who suffer from in-
creased risk of inflammation.
DW appeared to elicit a whole-body inflammatory re-
sponse among the older women as indicated by elevated
CRP levels in the plasma 48 h post-DW, a reliable
marker of systemic inflammation [42] Furthermore, rest-
ing CRP levels in older women were twice as high com-
pared to a study we conducted with young women at
1825 year of age [43]. However, 8 weeks of high-AVA
supplementation completely abolished CRP response to
DW seen in the control diet group at 48 h. Inflammation
is a double-edged sword. While at young age inflamma-
tion in response to heavy muscle contraction especially
eccentric contraction is viewed as a necessary process
for muscle to recover from injury, among aged human
subjects muscle growth and repair appear to be inhibited
at high level of inflammation [11]. Furthermore, systemic
inflammation has been shown to disrupt local inflamma-
tory responses that are responsible for muscle repair
[35]. The repercussions of a lifetime of repeated inflam-
matory response are thought to be experienced in the
aged individuals as the result of a process known as
AVA supplementation suppressed pro- inflammatory
cytokine production
Inflammation is associated with increased pro-inflammatory
cytokine production, which could occur in both activated
leukocytes and injured muscle cells [35]. In the current
study, DW did not significantly increase plasma levels of
three major pro-inflammatory cytokines among older
women, presumably because the DW protocol was not
strenuous enough. However, plasma IL-1βconcentration
was decreased at rest and 24 h post-DW among subjects re-
ceiving high-AVA supplementation, whereas TNF-αlevel
showed a trend of reduction. It is known that plasma IL-1β
is associated with increased adhesion molecule expression,
hypothalamic modulation of body temperature, and hyper-
algesia [44]. By reducing IL-1β, AVA might have decreased
leukocyte invasion and, together with the decrease in neutro-
phil respiratory burst, protect skeletal muscle from elevated
inflammatory status seen among older women [45]. Reduced
plasma TNF-αmight also play a role in attenuating NFκBac-
tivation and NRB in response to DW. Guo [38] reported
that the inhibitory effect of AVA on the expression of pro-
inflammatory cytokines was mediated through NFκBactiva-
tion in HAEC. Our finding that AVA could suppress NFκB
activation in human plasma mononuclear cells provided fur-
ther evidence that AVA may inhibit inflammatory responses
through a common pathway of NFκB.
AVA had no adverse effect on blood antioxidant and
redox status
Besides AVA, oats contain a variety of phytochemicals
such as phytic acid, polyphenols, flavonoids, and tocols
that function as antioxidants [18]. Thus, oat supplemen-
tation, regardless of AVA concentration, significantly in-
creased plasma TAC indicating an overall antioxidant
protection. There has been a concern, however, about a
high dose of dietary antioxidant supplementation that
may cause some adverse effects such as interference with
intrinsic antioxidant systems and preventing exercise-
induced metabolic benefit [17]. In older women receiv-
ing 8-weeks of high-AVA supplementation, erythrocyte
SOD activity showed no change, whereas GPx activity
showed a modest but significant reduction (Table 2).
Plasma GSH content and GSH:GSSG ratio were normal
Table 2 Erythrocyte antioxidant enzyme activity and plasma glutathione status
Rest 408 ± 20.6 410 ± 19.9 440 ± 18.9 452 ± 16.2 5.90 ± 0.19 5.90 ± 0.10 1.10 ± 0.09 1.10 ± 0.13 5.36 ± 0.20 5.36 ± 0.19
24 h
393 ± 34.6 436 ± 10.0 399 ± 19.7 445 ± 19.3 6.57 ± 0.19 6.26 ± 0.12 1.15 ± 0.08 1.20 ± 0.10* 5.71 ± 0.21 5.20 ± 0.04
48 h
383 ± 15.3 403 ± 20.3 406 ± 14.1 436 ± 50.2 6.44 ± 0.21 7.05 ± 0.12 1.07 ± 0.10 1.14 ± 0.13 6.03 ± 0.22* 6.18 ± 0.17*
Rest 374 ± 38.7 419 ± 21.1 419 ± 14.1 319 ± 17.9¥ 5.76 ± 0.17 6.46 ± 0.20 1.07 ± 0.07 1.16 ± 0.12 5.41 ± 0.15 5.59 ± 0.13
24 h
353 ± 23.6 362 ± 60.1 376 ± 11.9 312 ± 24.6¥ 6.00 ± 0.15 6.65 ± 0.18 1.19 ± 0.05* 1.19 ± 0.13 5.03 ± 0.17 5.57 ± 0.10
48 h
389 ± 17.5 449 ± 6.5§ 397 ± 11.9 336 ± 61.9 6.27 ± 0.08 6.48 ± 0.15 1.02 ± 0.07 1.10 ± 0.06 6.16 ± 0.16* 5.89 ± 0.17
Note: Data are mean ± SEM (N = 8). SOD, superoxidae dismutase. Gpx, glutathione peroxidase. GSH, reduced glutathione; GSSG, glutathione disulfide. DW, downhill
walking (see text for details). * P < 0.05, 24 or 48 h Post-DW vs. Rest. § P < 0.05, Post-supplementation vs. Presupplementation. ¥ 0.05 < P < 0.1, AVA vs. Control.
Koenig et al. Nutrition Journal 2014, 13:21 Page 9 of 11
both at rest and in response to DW. These data indicate
that despite the clear benefit of anti-inflammatory ef-
fects, high-AVA supplementation did not cause major
adverse effects on the endogenous antioxidant system.
The modest drop in GPx activity in red blood cells
should not raise a concern as the GPx in vivo activity
has a large margin of protection due to its relatively low
Km (~1 mM).
High levels of dietary AVA significantly decreased sys-
temic inflammatory response of the older women to
downhill walking as indicated by lowered neutrophil re-
spiratory burst activity and plasma CRP concentration.
AVA supplementation attenuated plasma IL-1βlevels
and suppressed mononuclear cell NFκB activation.
These effects did not adversely affect the endogenous
antioxidant system. Thus, dietary supplementation of
AVA at the given dose appeared to be a useful dietary
supplement in reducing inflammation after demanding
physical exercise.
AVA: avenanthramides; BMI: body mass index; CK: ceatine kinase;
CRP: C-reactive protein; DW: downhill walking; GSH: glutathione;
GSSG: glutathione disulfide; GPx: glutathione peroxidase; IL: interleukin; (NF)
κB: nuclear factor-kappaB; NRB: neutrophil respiratory burst; ROS: reactive
oxygen species; SOD: superoxide dismutase; TAC: total antioxidant capacity;
TNF-α: tumor necrosis factor-α.
Competing interests
The authors declare that they have no competing interests.
RK and LLJ designed research; RK, JRD and CK conducted research; RK
analyzed data; RK, CK, YC, and LLJ wrote the paper; TOZ formatted the
paper; LLJ had primary responsibility for final content. All authors read and
approved the final manuscript.
This research was supported by a grant from the University of Wisconsin
Author details
Department of Kinesiology, University of WisconsinMadison, Madison,
WI 53706, USA.
Laboratory of Physiological Hygiene and Exercise Science,
University of Minnesota, 1900 University Avenue, Minneapolis, MN 55455,
Quaker Oats Center of Excellence, PepsiCo Nutrition, 617 W Main
Street, Barrington, IL 60010, USA.
Received: 1 November 2013 Accepted: 4 March 2014
Published: 19 March 2014
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Cite this article as: Koenig et al.:Avenanthramide supplementation
attenuates exercise-induced inflammation in postmenopausal women.
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Koenig et al. Nutrition Journal 2014, 13:21 Page 11 of 11
... 64 Similar results were obtained in a study enrolling postmenopausal women (16 women aged 50−80 years), and Avns supplementation (9.2 mg in cookies) dramatically reduced plasma levels of IL-1β and C-reactive protein after exercise. 65 A subsequent study indicated that the molecular mechanism by which Avns reduce the inflammatory response might be via the attenuation of nuclear factor kappa B (NF-κB) activation in skeletal muscle cells. 66 In general, all of the results showed that Avns exerted essential roles in mitigating in vitro and in vivo inflammation, indicating that Avns might possess potential roles in preventing many chronic diseases related to inflammation. ...
... Long-term eccentric exercise elevates inflammatory reactions and causes muscle damage. 63,65 Injured muscle tissue releases proinflammatory cytokines that subsequently stimulate the expression of adhesion molecules on the surface of endothelial cells, which might lead to decreased muscle metabolism and contraction. 68 After Avn supplementation in DR subjects (11 male and 13 female volunteers receiving cookies containing 206 mg/kg or 0 mg/kg per day) for 8 weeks, the results showed that the expression of inflammatory cytokines and cell adhesion molecules in muscle cells was reduced, which alleviated the inflammatory response and muscle injury caused by exercise emergency. ...
... 63 A study that enrolled 16 DW female subjects (orally administered cookies with 9.2 mg or 0.4 mg Avns each day for 8 weeks) indicated that supplementation with Avns could inhibit the expression of proinflammatory factors (IL-1β) in muscle cells and mitigate the adverse effects of DW on muscle. 65 In addition, more direct evidence was obtained from Avn-treated C2C12 cells. After pretreatment with Avns (30 μM for 24 h), the results showed that Avns could reverse TNFα-induced expression of proinflammatory cytokines by inhibiting the NF-κB pathway and suppress TNF-a-induced muscle atrophy. ...
... For instance, WG supports maintaining physiological homeostasis by modulating inflammatory reactions (12,14). Hence, oat and its components have been investigated and recognized as beneficial anti-inflammatory agents (15,16). However, some studies have reported that oats actually have no anti-inflammatory effects (17,18). ...
... The full texts of the 33 remaining studies were examined to determine their eligibility, and 10 studies were excluded. Finally, 23 RCTs were selected for systematic review and meta-analysis (16)(17)(18)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45). The detailed workflow is shown in Figure 1. ...
... Among the included RCTs, 16 were conducted on parallel groups (16, 17, 26-28, 30-34, 37-39, 42, 43, 45), while the others were crossover designs. Five studies recruited only male or female subjects (16,17,27,38,39), while the remaining studies included both sexes. The studies mostly comprised healthy subjects, followed by patients with dyslipidemia and type 2 diabetes. ...
Full-text available
Background: Oat and its compounds have been found to have anti-inflammatory effects. Through this systematic review and meta-analysis, we aimed to determine an evidence-based link between oat consumption and inflammatory markers. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. By the end of April 2021, we included randomized controlled trials (RCTs) that investigated the anti-inflammatory effect of oat and oat-related products through screening PubMed, Embase, Web of Science, , and CENTRAL. Meta-analysis was conducted with a random-effect model on the standardized mean difference (SMD) of the change scores of inflammatory markers, including C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8). Subgroup analyses were conducted to stratify confounding variables. The risk of bias was evaluated using the Cochrane risk of bias tool and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was applied to report the quality of evidence. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42021245844). Results: Systematic screening of five databases yielded 4,119 studies, of which 23 RCTs were finally selected. For the four systemic inflammatory markers analyzed, no significant alterations were found after oat consumption. However, oat intake was found to significantly decrease CRP levels in subjects with one or more health complications (SMD: −0.18; 95% CI: −0.36, 0.00; P = 0.05; I ² = 10%). Furthermore, IL-6 levels were significantly decreased in subjects with dyslipidemia (SMD = −0.34; 95% CI: −0.59, −0.10; P = 0.006; I ² = 0%). These beneficial effects might be attributed to the effects of avenanthramide and β-glucan. Conclusions: Overall evidence supporting the alleviation of inflammatory response by oat intake was poor, calling for future studies including a larger sample size to confirm the findings.
... Oat contains many essential amino acids (methionine, cysteine, threonine, isoleucine, tryptophan, valine, leucine, histidine, methionine, phenylalanine, and tyrosine) all are necessary for biological process inside human bodies [5]. Also, it contains high antioxidant activity components such as tocopherols, tocotrienols, and flavonoids [6]. Likewise, fibres from oat have a positive effect on health since their consumption has been related to a decreased incidence of several types of diseases as due to its beneficial effects like decreasing the constipation, decreasing the time of intestinal transit, cholesterol and glycaemic levels, trapping substances that can be dangerous for the human organism (mutagenic and carcinogenic agents), stimulating the proliferation of the intestinal flora etc. ...
... 50% WOF+30% WG+15% flaxseed +5% Fig1. Effect of adding WOF, WG, PP and flaxseed to WF on DSCFatty acid composition of wheat germThe composition of wheat germ fatty acids was determined by GC and presented in table(6). Wheat germ flour contained 19.88% saturated fatty acids (SFA), 78.67% unsaturated fatty acids (USFA) consisting of FORMULATION AND EVALUATION OF BISCUITS FROM FUNCTIONAL FLOUR … __________________________________________________________________________________________________________________ ________________________________________________ crystalline region corresponds to the distribution of amylopectin short chain and not to the propagation of the crystalline region which corresponds to the amylase [WG+15% flaxseed +5% PP Fig1. ...
... Apart from specific substances, recent investigations have revealed that certain meal compositions seem to impact the level of oxidative stress agents following exercise. Especially, avenanthramide (AVA), which is mainly found in oats, has been a well-discussed topic in the scientific community due to its strong antioxidant activity in animal and human studies [18][19][20][21]. Previous studies showed that both the hydroxyl groups and the α, β-unsaturated carbonyl moiety are crucial for the antioxidant properties of AVAs, and they act directly or indirectly to scavenge ROS [22]. ...
... Previous research findings have indicated AVA's antioxidant and anti-inflammatory properties in both preclinical and human studies [18][19][20][21]. Zhang et al. [19] and Koenig et al. [18] investigated the effects of chronic AVA supplementation on exercised-induced ROS generation in their clinical studies. ...
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High-intensity interval training (HIIT) has been demonstrated to increase the generation of reactive oxygen species (ROS). Therefore, strategies to mitigate excessive ROS productions could be useful to reduce the negative consequences of oxidative damage for health, as well as for physical, performances. The aim of this study was to investigate the acute effects of pre-exercise oatmeal consumption on exercise-induced ROS generation in young, healthy women. Thirty-four participants were randomly allocated in one of two groups: oatmeal prior to HIIT (oatmeal; n = 17) or HIIT alone (control; n = 17). Blood samples were obtained at pre-meal, pre-HIIT, immediately post-HIIT, and 15 min after HIIT. Electron paramagnetic resonance (EPR) spectroscopy was used to analyze the concentrations of ROS in the capillary blood. In addition, the blood glucose and blood lactate levels were measured. Immediately post-HIIT, the ROS generation in the oatmeal group was significantly lower in contrast to the control group (p < 0.05). A significant interaction effect of time × meal (p < 0.05; η2 = 0.234) was detected from the pre-meal to 15 post-HIIT for ROS production. Moreover, significant differences in the blood glucose levels were observed between the groups at pre-HIIT and immediately post-HIIT (p < 0.05). In conclusion, the consumption of oatmeal before HIIT may mitigate exercise-induced ROS production.
... The predominant AVAs found in oats are 2c, 2f, and 2p according to the systematic nomenclature developed by Dimberg (46). The antioxidant properties of AVAs have been verified in numberous clinical trials (47). In addition, in terms of lipids metabolism, AVAs showed a cholesterol-lowering property by notably decreasing the level of TC, TG, and LDL-C in healthy subjects (48). ...
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Phytochemicals derived from oats are reported to possess a beneficial effect on modulating dyslipidemia, specifically on lowering total and LDL cholesterol. However, deeper insights into its mechanism remain unclear. In this randomized controlled study, we assigned 210 mildly hypercholesterolemic subjects from three study centers across China (Beijing, Nanjing, and Shanghai) to consume 80 g of oats or rice daily for 45 days. Plasma lipid profiles, short chain fatty acids (SCFAs), and fecal microbiota were measured. The results showed that total cholesterol (TC) and non-high-density lipoprotein cholesterol (non-HDL-C) decreased significantly with both oats and rice intake after 30 and 45 days. The reduction in TC and non-HDL-C was greater in the participants consuming oats compared with rice at day 45 (p = 0.011 and 0.049, respectively). Oat consumption significantly increased the abundance of Akkermansia muciniphila and Roseburia, and the relative abundance of Dialister, Butyrivibrio, and Paraprevotella, and decreased unclassified f-Sutterellaceae. In the oat group, Bifidobacterium abundance was negatively correlated with LDL-C (p = 0.01, r = −0.31) and, TC and LDL-C were negatively correlated to Faecalibacterium prausnitzii (p = 0.02, r = −0.29; p = 0.03, r = −0.27, respectively). Enterobacteriaceae, Roseburia, and Faecalibacterium prausnitzii were positively correlated with plasma butyric acid and valeric acid concentrations and negatively correlated to isobutyric acid. HDL-C was negatively correlated with valeric acid (p = 0.02, r = −0.25) and total triglyceride (TG) was positively correlated to isovaleric acid (p = 0.03, r = 0.23). Taken together, oats consumption significantly reduced TC and LDL-C, and also mediated a prebiotic effect on gut microbiome. Akkermansia muciniphila, Roseburia, Bifidobacterium, and Faecalibacterium prausnitzii, and plasma SCFA correlated with oat-induced changes in plasma lipids, suggesting prebiotic activity of oats to modulate gut microbiome could contribute towards its cholesterol-lowering effect.
... In addition, a study found that oat protein supplementation can help alleviate the side effects of eccentric exercise like induced muscle damage, skeletal soreness, and loss of performance after downhill running or vertical jump [89]. AVA supplementation in women showed a significant decrease of neutrophil respiratory burst, NFκB activation, plasma IL-6 concentration, erythrocyte glutathione peroxidase activity, and increase of glutathione levels, which suggests that AVAs are a promising supplementation to decrease the systemic inflammatory response and attenuate the inflammation triggered by high physical exercise [90,91]. Another study also suggested that AVAs are potential inhibitors of the NFκB-mediated inflammatory response in select cell lines [92]. ...
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Oat is among the food crops and ancient grains cultivated and consumed worldwide. It is gaining in popularity owing to its nutritional composition and multifunctional benefits of select bioactive compounds. Beta-glucan is an important component of dietary fiber found in oat grains. It is the major active compound in oats with proven cholesterol-lowering and antidiabetic effects. Oats also provide substantial levels of other bioactive compounds such as phenolic acids, tocols, sterols, avenacosides, and avenanthramides. The consumption of oats has been determined to be beneficial for human health by promoting immunomodulation and improving gut microbiota. In addition, oat consumption assists in preventing diseases such as atherosclerosis, dermatitis, and some forms of cancer. While much has been published in relation to oat nutrients and oat fibers and their impact on major diseases, the oat industries and consumers may benefit from greater knowledge and understanding of clinical effects, range of occurrence, distribution, therapeutic doses and food functional attributes of other oat bioactives such as avenanthramides and saponins as well as other anti-inflammatory agents found in the cereal. This review focuses on the various studies relevant to the contribution of the consumption of oats and oat-based products in preventing human diseases and promoting human health.
... Similarly, avenanthramides (9.2 mg/d for 8 weeks) blunted acute eccentric exercise-induced neutrophil respiratory burst in 16 young women. Such an effect of avenanthramides on neutrophil respiratory burst was also noted in 16 older women [111]. These results indicate that avenanthramides are capable of mitigating exercise-related inflammation but their effect on the immunity against infection remains to be examined. ...
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Optimal nutrition is the foundation for the development and maintenance of a healthy immune system. An optimal supply of nutrients is required for biosynthesis of immune factors and immune cell proliferation. Nutrient deficiency/inadequacy and hidden hunger, which manifests as depleted nutrients reserves, increase the risk of infectious diseases and aggravate disease severity. Therefore, an adequate and balanced diet containing an abundant diversity of foods, nutrients, and non-nutrient chemicals is paramount for an optimal immune defense against infectious diseases, including cold/flu and non-communicable diseases. Some nutrients and foods play a larger role than others in the support of the immune system. Oats are a nutritious whole grain and contain several immunomodulating nutrients. In this narrative review, we discuss the contribution of oat nutrients, including dietary fiber (β-glucans), copper, iron, selenium, and zinc, polyphenolics (ferulic acid and avenanthramides), and proteins (glutamine) in optimizing the innate and adaptive immune system’s response to infections directly by modulating the innate and adaptive immunity and indirectly by eliciting changes in the gut microbiota and related metabolites.
Cardiovascular diseases have been the leading cause of death worldwide for decades. Some animal studies have indicated that oatmeal could improve gut microbiota and cardiometabolic risk markers. However, vivo evidence remained limited, especially in individuals with mild hypercholesterolemia. Our purpose was to explore the beneficial effects of oatmeal on serum lipids, oxidative stress and inflammation levels, and their correlations with gut microbiota and short-chain fatty acids (SCFAs) in mildly hypercholesterolemic individuals. The study was a randomized, single-blind, placebo-controlled trial. A total of 62 qualified participants were randomly divided into control group and oatmeal group with a 45-day follow-up. 16S rDNA and Gas-Chromatography Mass Spectrometry were employed respectively to measure the changes in gut microbiota and SCFAs at the start and the end of the intervention period. Cardiometabolic risk markers were assayed via commercial kits. The results suggested that oatmeal could significantly decrease serum total cholesterol (TC) (-8.59%, p=0.013), low density lipoprotein cholesterol (LDL-c) (-12.97%, p=0.004) and non-high density lipoprotein cholesterol (non-HDL-c) (-10.98%, p=0.040) level. In terms of oxidative stress, oatmeal significantly increased serum total antioxidant capacity (T-AOC) (21.98%, p<0.001), superoxide dismutase (SOD) (15.53%, p=0.044) levels and decreased concentration of malondialdehyde (MDA) (-19.11%, p=0.033) compared with control group. While no significant effect was observed in inflammatory factors. SCFAs results indicated that oatmeal could significantly increase serum acetic acid, propionic acid and valeric acid. The results of 16S rDNA showed that there was a significant difference in the alteration of β-diversity between groups throughout the whole trial. Oatmeal resulted in the increases of Akkermansia, Dialister, Faecalibacterium, Barnesiella, Agathobacter, Lactobacillus and the decrease of Ruminococcaceae-MK4A214-group. Correlation analysis further suggested that the lipids regulation effect of oatmeal may be mainly mediated by Lactobacillus and Dialister, as well as some SCFAs (e.g., acetic acid and propionic acid), while Barnesiella and Akkermansia may play a crucial role in ameliorating oxidative stress level. In conclusion, despite of its small sample size, the present study is the first clinical trial performed in Chinese individuals with mild hypercholesterolemia to explore the effects of oatmeal on serum lipids, oxidative stress, inflammation levels, and gut microbiota. The results demonstrated that oatmeal could induce some beneficial changes in serum lipids, oxidative stress, gut microbiota composition and SCFAs. Correlation analysis further extended our understanding of the role of gut microbiota and SCFAs in improving cardiometabolic risk markers.
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Background The dynamic balance between oxidation and anti-oxidation in the body’s internal environment has a significant meaning for human health. Physical exercise and antioxidative supplementation could affect the balance of oxidation and anti-oxidation systems. The evidence on the effects of physical exercise and antioxidative supplementation is mixed. Aims To identify the effects of physical exercise, antioxidative supplementation, and their combination on the dynamic balance between oxidation and anti-oxidation in different subgroups of healthy adults. Methods All studies which reported randomized controlled trials with healthy participants were screened and included from the databases of PubMed, Medline, Embase, and Ovid. All participants were reclassified according to their different daily life activities. All physical exercise interventions were reclassified according to the intensity. The effect size would be calculated in percent or factor units from the mean level change with its associated random-effect variance. Result There were 27 studies included in this review. The agreement between authors by using The Cochrane Collaboration Risk of Bias Assessment Tool reached a kappa-value of 0.72. Maintaining a regular physical exercise routine in an appropriate intensity would be beneficial to the body’s anti-oxidative potential. Anti-oxidative supplementation could have some positive but limited effects on the body’s anti-oxidative status and complex interaction with physical exercise. Conclusion Keeping a regular physical exercise routine and gradually increasing its intensity according to the individual’s daily life activity might be a better choice to maintain and enhancing the body’s antioxidation potential, only using anti-oxidative supplementation is not recommended. More research is needed to explore the best combination protocol. Registration Number CRD42021241995.
This chapter introduces the present knowledge on major bioactive compounds found in whole grain cereals such as wheat, rye, oat and barley. Cereal products are major dietary sources of folate, contributing to ca. 15-30% of the total intake. Cereals are also major sources of the methyl donors glycine, betaine, choline and trigonelline. Whole grains are a good dietary source of carotenoids. Among cereals, corn has the highest average content of total carotenoids compared to wheat or barley. The most common Plant Sterols in cereal grains include sitosterol, campesterol, stigmasterol, Δ5-avenasterol, Δ7-avenasterol, and the saturated sterols sitostanol and campestanol. The chapter discusses bioavailability and metabolism of bioactives in the body as well as their possible health implications. With regard to health, it focuses on the mechanisms whereby bioactive compounds may decrease the risk for type 2 diabetes, coronary heart disease and cancers.
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Agaricus blazei Murill is an edible and medicinal mushroom. In the previous study, we have proved that extracts of A. blazei inhibit human peripheral blood mononuclear cell (PBMC) proliferation activated with phytohemagglutinin (PHA). Currently, we purified 4-hydroxy-17-methylincisterol (4-HM; C21H33O3) from A. blazei investigated its regulatory effects on cytokine productions and cell proliferation of PBMC induced by PHA. The results indicated that 4-HM suppressed, in activated PBMC, the production and mRNA expression of interleukin-2 (IL-2), IL-4, tumor necrosis factor- α , and interferon- γ in a concentration-dependent manner. This inhibition was not related to cell viability. While 4-HM did not affect ERK phosphorylation and its downstream c-fos gene expression in PBMC induced by PHA, it decreased both NF-AT and NF- κ B activation. The upstream signaling of NF-AT and NF- κ B, intracellular calcium concentrations ([Ca(2+)]i), and protein kinase C theta (PKC θ ) activation in PHA-treated PBMC were reduced by 4-HM. The data demonstrated that the suppressant effects of 4-HM on cell proliferation in PBMC activated by PHA appeared to be mediated, at least in part, through inhibition of Ca(2+) mobilization and PKC θ activation, NF-AT and NF- κ B activation, and cytokine transcripts and productions of PBMC. We suggested that A. blazei contained a potential immunomodulator 4-HM.
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Age associated immune dysregulation results in a pro-inflammatory state and increased susceptibility to infections and autoimmune diseases. Studies show that signaling initiated at the T cell antigen receptor (TCR) is impaired in CD4+ T cells from old compared to young mice. Here we examined TCR-inducible gene expression changes in CD4+ T cells during human aging. We reveal a dichotomy in gene expression mediated by the inducible transcription factor NF-κB. Most NF-κB target genes are not induced in a sustained manner in cells derived from older compared to younger individuals. However, a subset of NF-κB target genes including genes associated with chronic pro-inflammatory state in the elderly, such as interleukin 1 and 6, continue to be up-regulated even in the absence of NF-κB induction. In addition, we identify other widespread changes in gene expression between cells derived from older and younger individuals. Surprisingly, many of the most noteworthy age-associated changes in human CD4+ T cells differ from those seen in murine models. Our studies provide the first view of age-associated alteration of TCR-inducible gene expression in human CD4+ T cells.
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Avenanthramides are a group of alkaloids that consist of an anthranilic acid derivative linked to a hydroxycinnamic acid derivative by a pseudo peptide bond, which are constituents of oat (Avena sativa L.) grain. The three most abundant avenanthramides, N-(4′-hydroxy-3′-methoxycinnamoyl)-5-hydroxyanthranilic acid (Bf), N-(4′-hydroxycinnamoyl)-5-hydroxyanthranilic acid (Bp), and N-(3′,4′-dihydroxycinnamoyl)-5-hydroxyanthranilic acid (Bc), were synthesized and purified. These were tested for antioxidant activity using two in vitro systems: inhibition of β-carotene bleaching and reaction with the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). Each avenanthramide displayed antioxidant activity in both systems. Bc had greater activity than Bp and Bf. Bc was nearly as active as the standard synthetic antioxidant, butylated hydroxytoluene (BHT) in the β-carotene system. In the DPPH system, Bc and Bf were more active than 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox®). The relative activities of the avenanthramides corresponded to those determined for their component hydroxycinnamic acid moieties using an aqueous DPPH system or in a lipophilic system that measured the autoxidation of methyl linoleate.
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Prevalence of the metabolic syndrome (METS) and its components significantly increase after the menopause. Related increased cardiovascular risk may partially be explained by a pro-inflammatory state. To assess pro-inflammatory cytokine serum levels in postmenopausal women with and without the METS. Serum of 90 postmenopausal women who previously participated in a METS screening programme was analysed for tumour necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6). Cytokine levels were compared among those with and without the syndrome, and for each of its components. Linear relationships were also assessed between cytokine levels and several continuous variables including each diagnostic METS criteria and menopausal symptoms assessed with the Menopause Specific Quality of Life tool (MENQOL). For all studied women mean age was 55.1 ± 7.3 years with 63.3% having abdominal obesity, 15.6% hyperglycaemia, 58.9% high triglycerides, 44.4% hypertension and 25.6% high total cholesterol levels. Women with the METS (n = 45) significantly had higher body mass index values, and higher rates of abdominal obesity, hyperglycaemia, hypertriglyceridemia, hypertension and lower HDL-C levels. Cytokine levels did not differ among women with or without the METS; however, independent of METS diagnosis those with abdominal obesity displayed significantly higher IL-6 levels and those with hypertension higher levels of both cytokines. Levels of both cytokines positively correlated with age and time since menopause, IL-6 positively correlating with waist circumference values and TNF-α positively with both systolic and diastolic blood pressure levels. A significant positive correlation was also found between the number of positive METS criteria (0-5) and both cytokine levels. Cytokine levels did not correlate with vasomotor and psycho-social MENQOL scores. Pro-inflammatory cytokine levels in this postmenopausal series positively correlated with age, time since the menopause, abdominal circumference, blood pressures levels and the number of positive METS diagnostic criteria. There is a need for more research in this regard.
Background: Age-related body-composition changes are associated with health-related outcomes in elders. This relation may be explained by inflammation and hemostatic abnormalities. Objectives: Our objectives were to evaluate the relation between body-composition measures [body mass index (BMI), total fat mass, and appendicular lean mass (aLM)] and C-reactive protein (CRP), interleukin 6 (IL-6), and plasminogen activator inhibitor 1 (PAI-1) and to explore the effect of obesity and sarcopenia on CRP, IL-6, and PAI-1 concentrations. Design: The data are from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study baseline visit (n = 286; mean age = 66.0 y). Total fat mass and aLM were assessed with a dual-energy X-ray absorptiometry scan. Linear regressions were performed between body-composition measures and CRP, IL-6, or PAI-1 concentrations. The effect of sarcopenia and obesity (defined as the percentage of fat mass) on CRP, IL-6, and PAI-1 concentrations was evaluated with the use of analyses of covariance. Results: CRP and IL-6 were positively associated with both BMI [β = 0.027 (P = 0.03) and β = 0.048 (P < 0.001), respectively] and total fat mass [β = 0.049 (P < 0.001) and β = 0.055 (P < 0.001), respectively] and were inversely associated with fat-adjusted aLM [β = −0.629 (P = 0.002) and β = −0.467 (P = 0.02), respectively]. PAI-1 was positively associated with both BMI (β = 0.038, P = 0.005) and total fat mass (β = 0.032, P = 0.007). No significant interaction was found between either obesity or sarcopenia and CRP, IL-6, and PAI-1 concentrations. Obesity remained significantly associated with high CRP and IL-6 concentrations after adjustments for sarcopenia. Conclusions: CRP and IL-6 are positively associated with total fat mass and negatively associated with aLM. Obesity-associated inflammation may play an important role in the age-related process that leads to sarcopenia. The relation of inflammation with sarcopenia was not independent of any of the considered obesity indexes.
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
Fractionation of methanolic extracts of oat groats and hulls by anion-exchange chromatography revealed the presence of a series of anionic, substituted cinnamic acid conjugates, trivially named avenanthramides. Two-dimensional thin-layer chromatography (TLC) showed groat extracts contain more than 25 distinct avenanthramides, while hull extracts contained about 20. Some 15 were common to both groat and hull preparations. The substances were purified by repeated column chromatography on Sephadex LH-20, using TLC to monitor purity, and crystallized from aqueous acetone. The complete structures of 10 avenanthramides have been elucidated using 1H and 13C nuclear magnetic resonance (NMR), mass spectroscopy (MS), ultraviolet absorption spectroscopy (UV), and hydrolytic techniques and confirmed by total synthesis. The physicochemical properties, potential biological activity, and distribution within the oat grain are discussed.
Oat (Avena sativa L.) is a source of many compounds that exhibit antioxidant activity. Vitamin E (tocols), phytic acid, phenolic compounds, and avenanthramides are the most abundant antioxidants in oat, and flavonoids and sterols are also present. These antioxidants are concentrated in the outer layers of the kernel. Several in vitro tests have been used to evaluate antioxidant activity of oat extracts. A few examples show that an oat-containing diet boosted the antioxidant capacity of serum or meat in animals. Avenanthramides may be a plant defense response, as these compounds are induced in oat leaves by rust spores or elicitors. Antioxidants function in helping to maintain the stability of processed oat products, and oat can stabilise oils and fats against rancidity. Possible future research should be aimed at increasing antioxidants by plant breeding and through a nutritional genomics approach. Additionally, we need to acquire knowledge about the bioavailability and function of antioxidants in human and animal systems. Methods for fractionation of oat to produce antioxidant co-products along with other high-value components should also be studied.