Bioavailability of plant pigment phytochemicals in Angelica keiskei in older adults: A pilot absorption kinetic study

Abstract

BACKGROUND/OBJECTIVES
Angelica keiskei is a green leafy vegetable rich in plant pigment phytochemicals such as flavonoids and carotenoids. This study examined bioavailability of flavonoids and carotenoids in Angelica keiskei and the alteration of the antioxidant performance in vivo.

SUBJECTS AND MATERIALS
Absorption kinetics of phytochemicals in Angelica keiskei were determined in healthy older adults (> 60 y, n = 5) and subjects with metabolic syndrome (n = 5). Subjects consumed 5 g dry Angelica keiskei powder encapsulated in gelatin capsules with a low flavonoid and carotenoid liquid meal. Plasma samples were collected at baseline, 0.5, 1, 2, 3, 4, 5, 6, 7, and 8 h. Samples were analyzed for flavonoids and carotenoids using HPLC systems with electrochemical and UV detection, respectively, and for total antioxidant performance by fluorometry.

RESULTS
After ingestion of Angelica keiskei increases in plasma quercetin concentrations were observed at 1-3 and 6-8 hr in the healthy group and at all time points in the metabolic syndrome group compared to baseline (P < 0.05). Plasma lutein concentrations were significantly elevated in both the healthy and metabolic syndrome groups at 8 hr (P < 0.05). Significant increases in total antioxidant performance were also observed in both the healthy and the metabolic syndrome groups compared to baseline (P < 0.05).

CONCLUSIONS
Findings of this study clearly demonstrate the bioavailability of phytonutrients of Angelica keiskei and their ability to increase antioxidant status in humans.

Full text

Nutrition Research and Practice 2014;8(5):550-557
ⓒ2014 The Korean Nutrition Society and the Korean Society of Community Nutrition
http://e-nrp.org
Bioavailability of plant pigment phytochemicals in Angelica
keiskei in older adults: A pilot absorption kinetic study
Camila R Correa1,2, C-Y. Oliver Chen1, Giancarlo Aldini3, Helen Rasmussen1, Carlos F Ronchi1,2, Carolina Berchieri-Ronchi1,2,
Soo-Muk Cho4, Jeffrey B Blumberg1 and Kyung-Jin Yeum5§
1Jean Mayer USDA- Human Nutrition Research Center on Aging, Tufts University, 711 Washington St., Boston, MA 02111, USA
2Department of Internal Medicine, Botucatu Medical School, São Paulo State University (UNESP), Distrito Rubiao Jr. s/n, 18618-970 Botucatu, SP, Brazil
3Department of Pharmaceutical Sciences, Università degli Studi di Milano, 20133 Milan, Italy
4National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Republic of Korea
5College of Biomedical and Health Sciences, Konkuk University, Chungju-si, 380-701, Republic of Korea
BACKGROUND/ OBJEC TIVES: Angelica keiskei is a green leafy vegetable rich in plant pigment phytochemicals such as flavonoids
and carotenoids. This study examined bioavailability of flavonoids and carotenoids in Angelica keiskei and the alteration of
the antioxidant performance in vivo.
SUBJECTS AND MATERIALS: Absorption kinetics of phytochemicals in Angelica keiskei were determined in healthy older adults
(> 60 y, n = 5) and subjects with metabolic syndrome (n = 5). Subjects consumed 5 g dry Angelica keiskei powder encapsulated
in gelatin capsules with a low flavonoid and carotenoid liquid meal. Plasma samples were collected at baseline, 0.5, 1, 2,
3, 4, 5, 6, 7, and 8 h. Samples were analyzed for flavonoids and carotenoids using HPLC systems with electrochemical and
UV detection, respectively, and for total antioxidant performance by fluorometry.
RESULTS: After ingestion of Angelica keiskei increases in plasma quercetin concentrations were observed at 1-3 and 6-8 hr
in the healthy group and at all time points in the metabolic syndrome group compared to baseline (P< 0.05). Plasma lutein
concentrations were significantly elevated in both the healthy and metabolic syndrome groups at 8 hr (P< 0.05). Significant
increases in total antioxidant performance were also observed in both the healthy and the metabolic syndrome groups compared
to baseline (P<0.05).
CONCLUSIONS: Findings of this study clearly demonstrate the bioavailability of phytonutrients of Angelica keiskei and their
ability to increase antioxidant status in humans.
Nutrition Research and Practice 2014;8(5):550-557; doi:10.4162/nrp.2014.8.5.550; pISSN 1976-1457 eISSN 2005-6168
Keywords: Angelica keiskei, quercetin, lutein, absorption kinetic, total antioxidant performance
INTRODUCTION11)
Angelica keiskei, a large perennial plant, which originated in
Japan, belongs to the Umbeliferae family. Since identification
of some constituents of the roots of Angelica keiskei by Kozawa
et al in 1961 [1] and 1978 [2,3], its biological functions, including
anti-carcinogenic [4-6], anti-thrombotic [7], anti-bacterial [8],
anti-hyperglycemic [9], and anti-hypertensive effects [10] have
been reported in various animal and cell models. Although
consumption of Angelica keiskei-based juice for eight weeks was
reported to reduce DNA damage in smokers [11], a study
showing the bioavailability of phytochemicals in Angelica keiskei
in humans is still lacking. It is generally accepted that the
bioavailability of phenolics in plants is relatively low due to poor
absorption, which is largely dependent on food matrix, sugar
moieties, interaction with other constituents, and the site of
absorption [12,13]. We recently reported major phytochemicals
as well as various phenolics in Angelica keiskei using an
integrated high resolution mass spectrometric and informatics
approach [14], and the stability of its major components in
different storage conditions [15].
Phytochemicals with antioxidant properties modify the anti-
oxidant capacities in the lipid- and water-soluble compartments
of the biological system in different degrees depending on its
hydrophilicity vs. lipophilicity [16]. In addition, the combination
of water-soluble and fat-soluble phytochemicals may well show
synergistic protective effects against oxidative stress in both
compartments due to their cross-talk [17]. Therefore, studying
the changes of antioxidant status after ingestion of antioxidant
rich Angelica keiskei along with its phytochemical status can be
biologically significant. The Total Antioxidant Performance
(TAP), developed by Aldini et al. [18] and validated by Beretta
This research has been supported in part by the BioGreen 21 Program (Code #20070301034009), Rural Development Administration, Korea and U.S. Department
of Agriculture, under agreement number 1950-51000-065-08S.
§Corresponding Author: Kyung-Jin Yeum, Tel. +82-43-840-3586, FAX. +82-43-840-3585, Email. kyeum@kku.ac.kr
Received: December 27, 2013, Revised: March 10, 2014, Accepted: March 12, 2014
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/)
which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Camila R Correa et al.
551
et al. [19], measures not only antioxidant capacity in both the
hydrophilic and lipophilic compartments of the biological system,
but also their synergistic/ cooperative interactions.
The metabolic syndrome is a constellation of interrelated
metabolic abnormalities, including central obesity, hypergly-
cemia, hypertension, and dyslipidemia. The rapid increase in
prevalence of metabolic syndrome [20,21] is projected to result
in future increases in diabetes [22] and cardiovascular disease
[23,24]. Individuals with metabolic syndrome show low serum
antioxidant concentrations, such as carotenoids [25-27], which
is attributed in part to elevated systemic oxidative stress and/or
reduced utilization of consumed nutrients.
Therefore, a pilot study was conducted in order to determine
the absorption kinetics of two major pigment phytochemicals
in Angelica keiskei, quercetin and lutein, and changes in plasma
total antioxidant performance in subjects with and without
metabolic syndrome in preparation for a clinical trial with
biochemical and clinical outcomes.
SUBJECTS AND METHODS
Subjects
Ten older adults (> 60 years) identified as either healthy (n
= 5) or as having metabolic syndrome (n = 5) were enrolled in
the current study. For this study, 126 potential subjects were
recruited, 121 subjects were prescreened using a questionnaire,
40 subjects were screened with a physical examination and
blood test, and 10 qualified subjects were admitted and
successfully completed the study. All study subjects were in
good health as determined by a medical history questionnaire,
physical examination, and normal results of complete blood
count. Subjects had normal hematological parameters, serum
albumin, liver function, and kidney function, did not have a
history of smoking, alcoholism, or cardiovascular, hepatic,
gastrointestinal, or renal diseases, and were not exogenous
hormone users. Subjects did not take any supplemental vitamin
or carotenoid for more than 6 wks before the start of the study
and were not heavy tea drinkers (> 2 cups/d). Subjects with
metabolic syndrome met the following parameters: 1) fasting
plasma glucose ≥5.6 mmol/L; 2) central obesity, defined as a
waist-hip ratio > 0.9 for men and > 0.85 for women; and 3) either
high blood pressure (≥130/85 mmHg) or high triacylglycerol
(≥1.7 mmol/L).
Study design
Subjects were supplemented with a one-time dose of 5 g
of Angelica keiskei, equivalent to approximately 50 g of fresh
vegetable, as a dry powder in a gelatin capsule. The supplement
was taken with a low flavonoid and carotenoid beverage con-
taining coconut milk, protein powder, ginger ale, and glucose,
and plain pita bread with butter. This meal was repeated again
at lunch. The macronutrient composition of this meal was: 534.2
kcal, 10.6 gm fat, 94.7 gm carbohydrate, and 15 gm protein.
The carotenoid/phytochemical composition was minimal, and
included 4 μg β-carotene, 24 μg lutein+zeaxanthin, 0.6 mg
vitamin C, and 0.4 mg α-tocopherol equivalents. The nutrient
composition of the diets was calculated with the use of
Nutrition Dada System for Research (NDSR), Food and Nutrient
Database Version 2008, University of Minnesota.
Blood samples (15 mL each) were taken from subjects at
baseline (12-h fasting), and at 30, 60, 100, 180, 240, 300, 360,
420, and 480 min following ingestion of the supplement.
Samples were protected from light and centrifuged for 15 min
(1,000 × g, 4°C) within 1 h after collection. Aliquots of plasma
were stored at -70°C until analysis. The study protocol was
approved by the Institutional Review Board of Tufts Medical
Center and Tufts University Health Sciences (IRB#8636), and all
subjects provided written informed consent to participate.
Chemicals and reagents
All-trans-ß-carotene (type II), α-carotene, cryptoxanthin,
lycopene, α-tocopherol, L-ascorbic acid, β-glucuronidase type
II, quercetin, uric acid, human serum albumin, and phospha-
tidylcholine (type XVI-E) were purchased from Sigma Chemical
Co. (St Louis, MO). Lutein was purchased from Kemin Industries
(Des Moines, IA). The fatty acid analogue 4,4-difluoro-5-(4-
phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undeca
noic acid (BODIPY 581/591) was purchased from Molecular
Probes (Eugene, OR). The lipophilic radical initiator, 2,2’-azobis
(4-methoxy-2,4-dimethylvaleronitrile) (MeO-AMVN) was pur-
chased from Wako Chemicals (Richmond, VA, USA). Delipidized
human serum (DHS) was purchased from SeraCare Life Sciences
(Oceanside, CA). All HPLC solvents were obtained from JT Baker
Chemical and were filtered through a 0.45-μm membrane filter
before use.
Determination of plasma carotenoids and tocopherols
Concentrations of plasma carotenoids and tocopherols were
measured using an HPLC system as previously described with
minor modifications [28]. Briefly, plasma samples (200 μL) were
extracted with 2 mL of chloroform:methanol (2:1) followed by
3 mL of hexane. Samples were dried under nitrogen air and
resuspended in 75 μL ethanol:methyl tert-butyl ether (2:1) of
which 25 μL was injected into the HPLC. The HPLC system
consisted of a Waters 2695 Separation Module, 2996 Photo-
diode Array Detector, a Waters 2475 Multi λ Fluorescence
Detector, a C30 carotenoid column (3 μm, 150 × 3.0 mm, YMC,
Wilmington, NC), and a Waters Millenium 32 data station. The
mobile phase was methanol:methyl tert-butyl ether:water
(85:12:3 by volume with 1.5 % ammonium acetate in water;
solvent A) and methanol:methyl tert-butyl ether:water (8:90:2
by volume with 1 % ammonium acetate in water; solvent B).
The gradient procedure has been previously reported [28].
Results were adjusted using an internal standard of echinenone.
The coefficients of variation (CV) for inter assay (n = 25) was
4% and for intra assay was 4% (n = 9). Recovery of the internal
standard averaged 97%.
Determination of plasma ascorbic acid and uric acid
Ascorbic acid was measured by an HPLC system using an
electrochemical detector (Bioanalytical system, N. Lafayette, IN),
as described by Behrens et al. [29]. Briefly, plasma sample was
immediately deproteinized with perchloric acid (250 mM) and
the supernatant was injected onto the HPLC system for ascorbic
acid analysis.
Uric acid was measured using an Olympus analyzer (Olympus

552
Absorption kinetics of Angelica keiskei
Phytochemicals gram dry wt one dose (5 g)
Lutein (μg) 414.9 ± 1.14 2,074.65 ± 5.7
α-Carotene (μg) 24.5 ± 3.98 122.5 ± 19.9
trans β-Carotene (μg) 216.24 ± 3.59 1,081.2 ± 17.9
9 cis β-Carotene (μg) 36.31 ± 1.53 181.5 ± 7.6
Quercetin (mg) 1.55 5.75
Catechin (mg) 0.51 2.57
Values are expressed as mean ± SEM.
Subjects ingested a one-time dose (5 g) of
Angelica keiskei
dry powder in gelatin
capsule.
Carotenoids were analyzed by a HPLC-UV system in triplicate. Flavonoids were
analyzed by a HPLC-ECD system in duplicate.
Table 1. Major carotenoid and flavonoid contents in Angelica keiskei ingested b
y
study participants
America Inc., Melvile, NY), as reported by Fossati et al. [30]. A
series of uricase and peroxidase reactions were involved in this
assay using 2,4,6,-tribromo-3-hydroxzy benzoic acid.
Determination of plasma flavonoids
Concentrations of free plus phase II enzyme-conjugated
flavonoids in plasma were determined using the HPLC method
of Chen et al. [31]. Briefly, 20 μL of vitamin C-EDTA (200 mg
ascorbic acid plus 1 mg EDTA in 1.0 mL 0.4 mol/L NaH2PO4,
pH 3.6), 20 μL of a 5 mg/L internal standard (2’,3’,4’-trihydroxya-
cetophenone), and 20 μL of β-glucuronidase/sulfatase (98
units/L β-glucuronidase and 2.4 units/L sulfatase) were added
to 200 μL of plasma and the mixture was incubated at 37°C
for 45 min. After enzyme digestion, flavonoids were extracted
with 500 μL of acetonitrile, and then 500 μL supernatant was
removed, dried under purified nitrogen, and reconstituted in
200 μL of an aqueous HPLC mobile phase. Flavonoids were
determined using an HPLC system equipped with a Zorbax ODS
C18 column (4.6 × 150 mm, 3.5 μm) and a Coularray 5600 A
detector (ESA, Inc. Chelmsford, MA). The quantification of
individual flavonoids was calculated according to calibration
curves constructed using authentic standards (Sigma, St. Louis,
MO), with linear relationships of R2 > 0.999. Analyses were
performed in duplicate. The quantitation limit on the column
for flavan-3-ols was 0.357 pmol. The CV of the intra- and
inter-day assays was 3.0 and 9.0%, respectively.
Determination of plasma total antioxidant performance (TAP)
Plasma total antioxidant performance (TAP) was determined
using the method first developed by Aldini et al. [18] for
measurement of total antioxidant capacity in both the hydro-
philic and lipophilic compartments of plasma, and validated by
Beretta et al [19]. It measures the rate of oxidation of 4,
4-difluoro-5-(4-phenyl-1, 3-butadienyl)-4-bora-3a,4a-diaza-s-inda-
cene-3-undecanoic acid (BODIPY 581/591), a lipid-soluble fluor-
escent probe, and uses the lipid-soluble radical initiator 2,2’-
azobis(4-methoxy-2,4-dimethylvaleronitrile) (MeO-AMVN). Oxidation
is determined by monitoring the appearance of green fluor-
escence of the oxidation product of BODIPY (λex =500 nm, λem
= 520 nm) using a 1420 multilabel counter (Wallac Victor 2,
Perkin Elmer Life Sciences, MA). The results are expressed as
TAP values, which represent the percentage of inhibition of
BODIPY oxidation in human serum with respect to that
occurring in a control sample consisting of BODIPY 581/591 in
phosphatidylcholine liposomes. Control samples were prepared
using liposomes (phosphatidyl choline 2.5 mg/ml) in delipidized
human serum.
Determination of pigment phytochemicals in Angelica keiskei
powder
Measurement of carotenoids using a HPLC-UV: Angelica keiskei
dry powder encapsulated in gelatin capsules was provided by
the National Institute of Agricultural Science and Technology,
Korea. Carotenoids were analyzed as previously reported, with
minor modifications [32]. Briefly, 100 mg lyophilized sample was
used for carotenoid analysis. Samples were incubated with
methanol for 2 hours at room temperature, followed by extra-
ction with tetrahydrofuran at least four times. The lipid-soluble
phytonutrients were quantified using high-performance liquid
chromatography (HPLC) with a C30 column (3 lm, 150 × 4.6 mm,
YMC, Wilmington, NC).The conditions of HPLC were the same
as those used in measurement of the plasma.
Measurement of flavonoids using a HPLC-ECD: Flavonoids were
sequentially extracted twice with acidified methanol (methanol:
glacial acetic acid:water, 50:3.7:46.3) from 100 mg of lyophilized
samples over a 16-hour period. The combined extract was dried
under nitrogen gas, and stored under nitrogen at -80°C. Prior
to analysis by HPLC using an electrochemical detector (ECD),
aglycones in the dry extract were obtained after sugar cleavage
using an acid-boiling treatment as described previously [33].
Following solvent removal under nitrogen gas and reconstitu-
tion in HPLC mobile phase A, flavonoids were analyzed using
the reverse phase HPLC-ECD method as described previously.
The limit of quantitation for flavonoids determined by HPLC-
ECD was 1 ng on the column. The linearities of calibration
curves of authentic standards with concentrations range from
0.01 to 2 ng/ml were P≥0.991.
Statistical analysis
Values are expressed as mean ± SEM. A repeated-measures
analysis of variance with a Holm-Sidak multiple comparison
tests was used to measure the effect of supplementation of
Angelica keiskei on plasma quercetin, lutein concentrations and
total antioxidant performance with respect to the baseline.
When an equal variance test failed, Friedman repeated measures
analysis of variance on ranks with Tukey’s and multiple compa-
rison tests were used. An unpaired t-test was used for comp-
arison of differences in characteristics and antioxidant concen-
trations between the healthy and metabolic syndrome groups.
Data analysis was performed using SigmaStat (Ver 3.1, Systat
Software Inc, Point Richmond, CA).
RESULTS
Nutrient contents in Angelica keiskei
The nutrient content of the Angelica keiskei consumed by
study participants is shown in Table 1. This plant is a good
source of antioxidant nutrients such as lutein, α-, trans β-, and
9-cis β- carotene and flavonoids; 5 g Angelica keiskei contains
2.07 mg of lutein, 1.08 mg of β-carotene, 5.75 mg of quercetin,
and 2.57 mg of catechin.

Camila R Correa et al.
553
Characteristics Healthy
(n = 5)
Metabol ic syndrome
(n = 5)
Age (yrs) 67 ± 3.6 68.2 ± 4.6
Body mass index (kg/m2) 24 ± 3.2 34.9 ± 4.3*
Systolic blood pressure (mmHg) 109.2 ± 12.8 130 ±16.2
Diastolic blood pressure 72.8 ± 5.7 72 ± 4.2
Total cholesterol (mmol/L) 5.15 ± 0.14 5.16 ± 0.44
HDL cholesterol (mmol/L) 1.98 ± 0.12 1.08 ± 0.10**
LDL cholesterol (mmol/L) 2.77 ± 0.09 3.05 ± 0.41
VLDL cholesterol (mmol/L) 0.40 ± 0.06 1.03 ± 0.22*
Triglyceride (mmol/L) 0.90 ± 0.12 2.27 ± 0.48*
Glucose (mmol/L) 5.13 ± 0.17 5.43 ± 0.18
Hemoglobin A1C (%) 6.06 ± 0.07 6.23 ± 0.14
Adiponectin (μg/mL) 19.4 ± 6.79 5.78 ± 1.05*
IL6 (pg/mL) 1.63 ± 0.46 2.30 ± 0.60
CRP(mg/L) 1.90 ± 1.10 3.84 ± 2.07
All values are expressed as mean ± SEM.
Significantly different from healthy study participants, *
P
<0.05, **
P
<0.01
(unpaired t-test).
HDL, high density lipoprotein; LDL, low density lipoprotein; VLDL, very low density
lipoprotein; IL-6, Interleukin-6; CRP, C-reactive protein.
Table 2. Baseline characteristics of study participants
Antioxidants Healthy (n = 5) Metabolic syndrome (n = 5)
Water soluble antioxidants (μmol/L)
Ascorbic acid 36.5 ± 14.0 31.8 ± 4.88
Uric acid 276.1 ± 28.3 380.0 ± 28.3*
Fat-soluble antioxidants (μmol/L)
Lutein 0.21 ± 0.03 0.11 ± 0.02*
Cryptoxanthin 0.15 ± 0.01 0.08 ± 0.02*
α-Carotene 0.20 ± 0.01 0.12 ± 0.03
β-Carotene 0.55 ± 0.19 0.21 ± 0.06
trans-Lycopene 0.51 ± 0.05 0.46 ± 0.12
5 cis- Lycopene 0.53 ± 0.06 0.38 ± 0.09
α-Tocopherol 40.52 ± 1.98 31.75 ± 6.82
Retinol 1.95 ± 0.08 1.91 ± 0.20
All values are expressed as mean ± SEM.
Significantly different from healthy study participants, *
P
<0.05 (unpaired t-test).
Table 3. Baseline plasma concentrations of antioxidant nutrients in study
participants
Fig. 1. Absorption kinetics of quercetin in plasma after ingesting 5 g of
A
ngelica
keiskei in older adults (aged ≥60 yr); healthy (A) and metabolic syndrome (B).
Data are expressed as mean±SEM (n=5 in each group). ND, not detected. One-way
repeated measures ANOVA wi th Tukey’s multiple comparison was performed. When an
equal variance test failed, Friedman repeated measures analysis of variance on ranks with
Tukey’s multiple comparison test was used. Significantly different as compared with the
baseline *
P
<0
.
05. Samples were analyzed by HPLC with ECD detection for quercetin.
(A)
(B)
Characteristics of the study subjects
Characteristics of the study subjects are shown in Table 2.
Although the difference between the two groups was not
significant, blood pressure tended to be higher in the metabolic
syndrome group than in the healthy group. The metabolic
syndrome group showed significantly higher average body
mass index (BMI) (P< 0.01). Significantly higher levels of trigly-
cerides and VLDL cholesterol were also observed in the
metabolic syndrome group (P< 0.05). HDL cholesterol (P<0.01)
and adiponectin (P< 0.05) levels were significantly lower in
metabolic syndrome subjects. The baseline plasma concen-
trations of phytochemicals in both groups are shown in Table
3. Significantly higher concentrations of uric acid and signi-
ficantly lower concentrations of lutein and cryptoxanthin were
observed in the metabolic syndrome group as compared to the
healthy group (P< 0.05). The reduced ascorbic acid concen-
trations of the current study participants were in the range of
25-50% of National Health and Nutrition Examination Survey
(NHANES III) serum total ascorbic acid concentration for the
similar age group (50-70 yrs) [34]. Although samples were
carefully collected and the reduced ascorbic acid concentrations
were analyzed immediately after collecting the samples, there
is a possibility that oxidation of reduced ascorbic acid might
occur during the sample process. The plasma α-tocopherol
concentrations of current study participants were in the range
of 50-85% of National Health and Nutrition Examination Survey
(NHANES III) serum vitamin E concentrations for the similar age
group (50-70 yr) [34].
Absorption kinetics of plant pigment phytochemicals after
ingestion of Angelica keiskei
After ingestion of Angelica keiskei, the plasma quercetin
concentrations of the healthy study participants (Fig. 1A)
increased significantly at 1, 2, and 3 h as compared to baseline
(P< 0.05), decreased after lunch at 4 and 5 h, and increased
significantly again at 6 h, maintaining the significantly elevated
level until 8 hours (P< 0.05). The plasma quercetin concen-
trations in the metabolic syndrome group were also significantly
increased (P< 0.05) from the baseline throughout all periods
(Fig. 1B). Changes of plasma lutein concentrations in the healthy
(Fig. 2A) and metabolic syndrome groups are shown in Fig. 2

554
Absorption kinetics of Angelica keiskei
Fig. 2. Absorption kinetics of lutein in plasma after ingesting 5 g of
A
ngelica
keiskei in older adults (aged ≥60 yr); healthy (A) and metabolic syndrome (B).
Data are expressed as mean± SEM (n= 5 in each group). One-way repeated measures
ANOVA wi th Tukey’s multiple comparison was performed. Significantly different as
compared with the basel ine *
P
<0
.
05. Samples were anal yzed by HPLC wi th UV
detection.
(A)
(B)
Fig. 3. Plasma total antioxidant performance after ingesting 5 g of
A
ngelica
keiskei in older adults (aged ≥60 yr); healthy (A) and metabolic syndrome (B).
Data are expressed as mean± SEM (n= 5 in each group). One-way repeated measures
ANOVA with Tukey’s multiple comparison was performed. When an equal variance test
failed, Friedman repeated measures analysis of variance on ranks with Tukey’s multiple
comparison test was used. Significantly different as compared with the baseline *
P
<0
.
05.
Samples were analyzed by fluorometry.
(A)
(B)
(Fig. 2B). The plasma lutein concentrations were significantly
increased (P< 0.05) at 8 h in both healthy and metabolic
syndrome groups as compared to those of the baseline after
ingesting 5g of Angelica keiskei dry powder.
Changes of plasma total antioxidant performance after ingestion
of Angelica keiskei
Changes in plasma total antioxidant performance (TAP) are
shown in Fig. 3. In healthy study participants (Fig. 3A), the TAP
values were significantly increased by 44 and 47% from the
baseline (P< 0.05) at 1 and 3 h after ingestion of Angelica keiskei
powder, decreased after lunch, and were again significantly
elevated at 6 and 7 hours (P< 0.05). In the metabolic syndrome
group (Fig. 3B), the values were significantly increased from the
baseline at 30 minutes after ingestion of Angelica keskei, then
fell slightly and showed another significant increase at 5 hours
with a subsequent decrease (P<0.05).
DISCUSSION
Findings of the current study demonstrate the bioavailability
of pigment phytochemicals rich in Angelica keiskei and their
ability to change antioxidant capacity in healthy elderly as well
as subjects with metabolic syndrome.
Subjects exhibiting dyslipidemia (high triglyceride and low
HDL cholesterol), elevated blood pressure and fasting glucose,
and central obesity were classified as having metabolic
syndrome [35], and the definition was used in the current study
for inclusion of subjects in the metabolic syndrome. In the
current study, due to the small number of subjects in each
group, blood pressure and glucose level did not differ between
the two groups. It is interesting to note that the metabolic
syndrome group showed significantly lower adiponectin levels,
consistent with its predictability of type II diabetes [36].
Consistent with the results of lower concentrations of
carotenoids and vitamins C and E in individuals with metabolic
syndrome shown in the Third National Health and Nutrition
Examination Survey (NHANES III) [26], in the current study, we
found that plasma concentrations of lutein and cryptoxanthin
were significantly lower in individuals with metabolic syndrome.
Similarly, a recent study examining 890 females and 646 males
showed that the mean concentrations of serum α- and β
-carotenes and the total concentration of the five carotenoids
(α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin,

Camila R Correa et al.
555
and lycopene) were significantly lower for subjects with
metabolic syndrome compared to those without the syndrome
[27]. Lower intakes of antioxidant-rich fruit and vegetables and
corresponding decreased serum concentrations may contribute
to progression of metabolic syndrome [37]. It is also plausible
that the elevated oxidative stress in metabolic syndrome may
cause increased utilization of antioxidants, resulting in lower
serum concentrations of antioxidants such as carotenoids [25].
Quercetin, a flavonol, is one of the most prevalent flavonoids
found in edible plants. In the current study, even though
quercetin was not detected in the fasting blood before
consumption of Angelica keiskei in both healthy and metabolic
syndrome subjects, it should be pointed out that the baseline
quercetin concentration has been reported to be approximately
50 nmol/L [13], slightly higher than the limit of quantification
(33 nmol/L) of the current study. Previous studies have
repeatedly demonstrated that the sugar moiety is a major
determinant of the intestinal absorption of quercetin [13,38,39].
We observed that plasma quercetin level increased in healthy
subjects within 1 hour after administration of Angelica keiskei,
declined after lunch, and increased again in the sixth hour and
remained elevated at 8 h after ingestion. Considering that 1)
the current study determined the total quercetin concentrations
in plasma after hydrolysis of conjugates formed from the phase
II detoxification pathway and that 2) quercetin is usually bound
to glucose and rutinose (a 6-o-rhamnosyl-glucose), the first peak
at 1hr is probably due to quercetin glucoside and the 6 hr peak
to quercetin rutinoside. This notion is supported by previous
reports by Graefe et al, who reported on the pharmacokinetics
of quercetin glucoside and quercetin rutinoside in humans [38].
Although subjects with metabolic syndrome also showed the
quercetin peak at 30 min and a decrease at 5 hr, the plasma
quercetin concentrations remained significantly high up to 8
hrs. It is possible that the altered gut microbiota [40] as well
as phase 1 and II enzymes [41,42] may contribute to the
differences in responses between healthy and metabolic
syndrome subjects.
In the current study, a significant increase in plasma lutein
was observed after ingestion of Angelica keiskei in both the
healthy and metabolic syndrome groups. However, there was
no significant alteration in plasma β-carotene concentrations
in both the healthy and metabolic syndrome groups. Research
indicates that absorption of carotenoids involves several factors,
including interaction between carotenoids [43]. It has been
reported that lutein may interfere with absorption of β-carotene
and is absorbed more efficiently than β-carotene [44,45]. In
addition, the two-fold larger amount of lutein than β-carotene
in Angelica keiskei may affect the absorption kinetics of these
carotenoids. A recent study reported that dietary phospholipid
content enhanced the absorption of β-carotene and lutein [46].
However, it is unknown whether increased fat accumulation in
individuals with metabolic syndrome enables such an effect.
Considering that clearance of a one-time dose of pure caro-
tenoid such as lutein or β-carotene has been shown to take
more than 18 days [45], elevated plasma carotenoid concen-
tration after consumption of Angelica keiskei would be main-
tained in circulation for an extended period of time. Due to
the small number of subjects in each group and their large
variations in response to Angelica keiskei consumption, there
was no significant difference in plasma concentrations of
quercetin or lutein in each time point between two groups.
In the current study, we observed an increase in antioxidant
performance in healthy subjects as well as subjects with
metabolic syndrome after ingestion of 5 g dry powder of
Angelica keiskei. It is interesting to note that the significant
changes of antioxidant capacity by physiologic dose of green
leafy vegetable, Angelica keiskei, considering that endogenous
plasma components such as protein and uric acid contribute
greatly to overall antioxidant capacity and dietary micronu-
trients may, thus play a relatively small role, as discussed
previously [47]. Active synergistic interactions among antioxi-
dant phytochemicals within and across hydrophilic and
lipophilic compartments of biological systems and various other
phytochemicals in Angelica keiskei may contribute to the
significant increase of antioxidant capacity. It may also be
possible that the test meal itself might have altered plasma
antioxidant capacity and such artifact could be overcome by
a cross-over intervention study with a control meal without
Angelica keiskei. However, in the current study, it is plausible
that the meal consumed by participants may not affect the
antioxidant capacity determined by a lipophilic approach [19]
since it contained very low amounts of antioxidant nutrients
(i.e. 0.6 mg vitamin C, 0.4 mg α-tocopherol, 24 μg lutein/
zeaxanthin). Several studies failed to show the changes in
various markers of antioxidant capacity such as the ferric-
reducing ability of plasma (FRAP), trolox-equivalent antioxidant
capacity (TEAC), and oxygen radical absorbance capacity (ORAC)
after daily consumption of 600 g of fruit and vegetables [48]
or 21-42 g of walnuts [49]. In the current study, it is plausible
that the high contents of phytochemicals in Angelica keiskei as
compared to other foods [15] and the low antioxidant status
of older subjects who underwent two weeks of low fruit and
vegetable diets prior to the intervention could contribute to
the increase of antioxidant capacity. It should be noted however
that the clinical significance of the alteration of antioxidant
capacity and of the difference between healthy and metabolic
syndrome subjects is not known.
Findings of the current study indicate the bioavailability of
plant pigment phytochemicals such as carotenoid and flavonoid
in Angelica keiskei and their association with increase of
antioxidant capacity in both subjects with and without meta-
bolic syndrome. Angelica keiskei can be beneficial for individuals
under elevated systemic oxidative stress.
ACKNOWLEDGEMENT
We thank the volunteers who participated in this study, the
Nutrition Evaluation Laboratory staff and the Metabolic
Research Unit Staff at the Jean Mayer US Department of
Agriculture Human Nutrition Research Center on aging at Tufts
University.
REFERENCES
1. Hata K, Kozawa M. Pharmacognostical studies on umbelliferous
plants. XVIII. On the constituents of the roots of Angelica Keiskei

556
Absorption kinetics of Angelica keiskei
Koidzumi. Yakugaku Zasshi 1961;81:1647-9.
2. Kozawa M, Morita N, Baba K, Hata K. Chemical components of the
roots of Angelica keiskei Koidzumi. II. The structure of the chalcone
derivatives (author's transl). Yakugaku Zasshi 1978;98:210-4.
3. Kozawa M, Morita N, Baba K, Hata K. Chemical components of the
roots of Angelica keiskei Koidzumi. III. The structure of a new
dihydrofurocoumarin (author's transl). Yakugaku Zasshi 1978;98:
636-8.
4. Motani K, Tabata K, Kimura Y, Okano S, Shibata Y, Abiko Y, Nagai
H, Akihisa T, Suzuki T. Proteomic analysis of apoptosis induced by
xanthoangelol, a major constituent of Angelica keiskei, in neuro-
blastoma. Biol Pharm Bull 2008;31:618-26.
5. Kimura Y. New anticancer agents: in vitro and in vivo evaluation
of the antitumor and antimetastatic actions of various compounds
isolated from medicinal plants. In Vivo 2005;19:37-60.
6. Akihisa T, Tokuda H, Hasegawa D, Ukiya M, Kimura Y, Enjo F, Suzuki
T, Nishino H. Chalcones and other compounds from the exudates
of Angelica keiskei and their cancer chemopreventive effects. J Nat
Prod 2006;69:38-42.
7. Fujita T, Sakuma S, Sumiya T, Nishida H, Fujimoto Y, Baba K, Kozawa
M. The effects of xanthoangelol E on arachidonic acid metabolism
in the gastric antral mucosa and platelet of the rabbit. Res Commun
Chem Pathol Pharmacol 1992;77:227-40.
8. Inamori Y, Baba K, Tsujibo H, Taniguchi M, Nakata K, Kozawa M.
Antibacterial activity of two chalcones, xanthoangelol and 4-hydro-
xyderricin, isolated from the root of Angelica keiskei KOIDZUMI.
Chem Pharm Bull (Tokyo) 1991;39:1604-5.
9. Kawabata K, Sawada K, Ikeda K, Fukuda I, Kawasaki K, Yamamoto
N, Ashida H. Prenylated chalcones 4-hydroxyderricin and xanth-
oangelol stimulate glucose uptake in skeletal muscle cells by
inducing GLUT4 translocation. Mol Nutr Food Res 2011;55:467-75.
10. Shimizu E, Hayashi A, Takahashi R, Aoyagi Y, Murakami T, Kimoto
K. Effects of angiotensin I-converting enzyme inhibitor from Ashi-
taba (Angelica keiskei) on blood pressure of spontaneously hyper-
tensive rats. J Nutr Sci Vitaminol (Tokyo) 1999;45:375-83.
11. Kang MH, Park YK, Kim HY, Kim TS. Green vegetable drink
consumption protects peripheral lymphocytes DNA damage in
Korean smokers. Biofactors 2004;22:245-7.
12. Williamson G, Manach C. Bioavailability and bioefficacy of
polyphenols in humans. II. Review of 93 intervention studies. Am
J Clin Nutr 2005;81:243S-255S.
13.Manach C, Williamson G, Morand C, Scalbert A, Rémésy C.
Bioavailability and bioefficacy of polyphenols in humans. I. Review
of 97 bioavailability studies. Am J Clin Nutr 2005;81:230S-242S.
14. Aldini G, Regazzoni L, Pedretti A, Carini M, Cho SM, Park KM, Yeum
KJ. An integrated high resolution mass spectrometric and infor-
matics approach for the rapid identification of phenolics in plant
extract. J Chromatogr A 2011;1218:2856-64.
15. Li L, Aldini G, Carini M, Oliver Chen CY, Chun HK, Cho SM, Park
KM, Correa CR, Russell RM, Blumberg JB, Yeum KJ. Characterisation,
extraction efficiency, stability and antioxidant activity of phytonu-
trients in Angelica keiskei. Food Chem 2009;115:227-32.
16. Yeum KJ, Aldini G, Chung HY, Krinsky NI, Russell RM. The activities
of antioxidant nutrients in human plasma depend on the
localization of attacking radical species. J Nutr 2003;133:2688-91.
17. Yeum KJ, Beretta G, Krinsky NI, Russell RM, Aldini G. Synergistic
interactions of antioxidant nutrients in a biological model system.
Nutrition 2009;25:839-46.
18. Aldini G, Yeum KJ, Russell RM, Krinsky NI. A method to measure
the oxidizability of both the aqueous and lipid compartments of
plasma. Free Radic Biol Med 2001;31:1043-50.
19. Beretta G, Aldini G, Facino RM, Russell RM, Krinsky NI, Yeum KJ.
Total antioxidant performance: a validated fluorescence assay for
the measurement of plasma oxidizability. Anal Biochem 2006;
354:290-8.
20. Ford ES, Giles WH, Mokdad AH. Increasing prevalence of the
metabolic syndrome among U.S. adults. Diabetes Care 2004;27:
2444-9.
21. Ervin RB. Prevalence of metabolic syndrome among adults 20 years
of age and over, by sex, age, race and ethnicity, and body mass
index: United States, 2003-2006. Natl Health Stat Report 2009:1-7.
22. Ford ES, Schulze MB, Pischon T, Bergmann MM, Joost HG, Boeing
H. Metabolic syndrome and risk of incident diabetes: findings from
the European Prospective Investigation into Cancer and Nutrition-
Potsdam Study. Cardiovasc Diabetol 2008;7:35.
23. Grundy SM. A constellation of complications: the metabolic
syndrome. Clin Cornerstone 2005;7:36-45.
24. Malone DC, Boudreau DM, Nichols GA, Raebel MA, Fishman PA,
Feldstein AC, Ben-Joseph RH, Okamoto LJ, Boscoe AN, Magid DJ.
Association of cardiometabolic risk factors and prevalent cardiova-
scular events. Metab Syndr Relat Disord 2009;7:585-93.
25. Hansel B, Giral P, Nobecourt E, Chantepie S, Bruckert E, Chapman
MJ, Kontush A. Metabolic syndrome is associated with elevated
oxidative stress and dysfunctional dense high-density lipoprotein
particles displaying impaired antioxidative activity. J Clin Endocrinol
Metab 2004;89:4963-71.
26. Ford ES, Mokdad AH, Giles WH, Brown DW. The metabolic syndrome
and antioxidant concentrations: findings from the Third National
Health and Nutrition Examination Survey. Diabetes 2003;52:2346-52.
27. Coyne T, Ibiebele TI, Baade PD, McClintock CS, Shaw JE. Metabolic
syndrome and serum carotenoids: findings of a cross-sectional
study in Queensland, Australia. Br J Nutr 2009;102:1668-77.
28. Zhao X, Aldini G, Johnson EJ, Rasmussen H, Kraemer K, Woolf H,
Musaeus N, Krinsky NI, Russell RM, Yeum KJ. Modification of
lymphocyte DNA damage by carotenoid supplementation in
postmenopausal women. Am J Clin Nutr 2006;83:163-9.
29. Behrens WA, Madère R. A highly sensitive high-performance liquid
chromatography method for the estimation of ascorbic and
dehydroascorbic acid in tissues, biological fluids, and foods. Anal
Biochem 1987;165:102-7.
30. Fossati P, Prencipe L, Berti G. Use of 3,5-dichloro-2-hydroxyben-
zenesulfonic acid/4-aminophenazone chromogenic system in direct
enzymic assay of uric acid in serum and urine. Clin Chem
1980;26:227-31.
31. Chen CY, Milbury PE, Lapsley K, Blumberg JB. Flavonoids from
almond skins are bioavailable and act synergistically with vitamins
C and E to enhance hamster and human LDL resistance to
oxidation. J Nutr 2005;135:1366-73.
32. Cho YS, Yeum KJ, Chen CY, Beretta G, Tang G, Krinsky NI, Yoon
S, Lee-Kim YC, Blumberg JB, Russell RM. Phytonutrients affecting
hydrophilic and lipophilic antioxidant activities in fruits, vegetables
and legumes. J Sci Food Agric 2007;87:1096-107.
33. Zhang Z, Kou X, Fugal K, McLaughlin J. Comparison of HPLC
methods for determination of anthocyanins and anthocyanidins in
bilberry extracts. J Agric Food Chem 2004;52:688-91.
34. Institute of Medicine. Dietary Reference Intakes for Vitamin C,

Camila R Correa et al.
557
Vitamin E, Selenium, and Carotenoids. Washington, D.C.: The
National Academies Press; 2000.
35. Alberti KG, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, Donato
KA, Fruchart JC, James WP, Loria CM, Smith SC Jr; International
Diabetes Federation Task Force on Epidemiology and Prevention;
Hational Heart, Lung, and Blood Institute; American Heart Asso-
ciation; World Heart Federation; International Atherosclerosis
Society; International Association for the Study of Obesity. Harmoni-
zing the metabolic syndrome: a joint interim statement of the
International Diabetes Federation Task Force on Epidemiology and
Prevention; National Heart, Lung, and Blood Institute; American
Heart Association; World Heart Federation; International Atheroscle-
rosis Society; and International Association for the Study of Obesity.
Circulation 2009;120:1640-5.
36. Torres S, Salgado-Ceballos H, Torres JL, Orozco-Suarez S, Díaz-Ruíz
A, Martínez A, Rivera-Cruz M, Ríos C, Lara A, Collado C, Guizar-
Sahagún G. Early metabolic reactivation versus antioxidant therapy
after a traumatic spinal cord injury in adult rats. Neuropathology
2010;30:36-43.
37. Montonen J, Knekt P, Järvinen R, Reunanen A. Dietary antioxidant
intake and risk of type 2 diabetes. Diabetes Care 2004;27:362-6.
38. Graefe EU, Wittig J, Mueller S, Riethling AK, Uehleke B, Drewelow
B, Pforte H, Jacobasch G, Derendorf H, Veit M. Pharmacokinetics
and bioavailability of quercetin glycosides in humans. J Clin
Pharmacol 2001;41:492-9.
39. Wiczkowski W, Romaszko J, Bucinski A, Szawara-Nowak D, Honke
J, Zielinski H, Piskula MK. Quercetin from shallots (Allium cepa L.
var. aggregatum) is more bioavailable than its glucosides. J Nutr
2008;138:885-8.
40. Vijay-Kumar M, Aitken JD, Carvalho FA, Cullender TC, Mwangi S,
Srinivasan S, Sitaraman SV, Knight R, Ley RE, Gewirtz AT. Metabolic
syndrome and altered gut microbiota in mice lacking Toll-like
receptor 5. Science 2010;328:228-31.
41. Dey A, Williams RS, Pollock DM, Stepp DW, Newman JW, Hammock
BD, Imig JD. Altered kidney CYP2C and cyclooxygenase-2 levels are
associated with obesity-related albuminuria. Obes Res 2004;12:
1278-89.
42. Furukawa S, Fujita T, Shimabukuro M, Iwaki M, Yamada Y, Nakajima
Y, Nakayama O, Makishima M, Matsuda M, Shimomura I. Increased
oxidative stress in obesity and its impact on metabolic syndrome.
J Clin Invest 2004;114:1752-61.
43. van Het Hof KH, West CE, Weststrate JA, Hautvast JG. Dietary factors
that affect the bioavailability of carotenoids. J Nutr 2000;130:503-6.
44. van den Berg H. Effect of lutein on beta-carotene absorption and
cleavage. Int J Vitam Nutr Res 1998;68:360-5.
45. Kostic D, White WS, Olson JA. Intestinal absorption, serum clearance,
and interactions between lutein and beta-carotene when admini-
stered to human adults in separate or combined oral doses. Am
J Clin Nutr 1995;62:604-10.
46. Marisiddaiah R, Baskaran V. Bioefficacy of beta-carotene is improved
in rats after solubilized as equimolar dose of beta-carotene and
lutein in phospholipid-mixed micelles. Nutr Res 2009;29:588-95.
47. Talegawkar SA, Beretta G, Yeum KJ, Johnson EJ, Carithers TC, Taylor
HA Jr, Russell RM, Tucker KL. Total antioxidant performance is
associated with diet and serum antioxidants in participants of the
diet and physical activity substudy of the Jackson Heart Study. J
Nutr 2009;139:1964-71.
48. Dragsted LO, Pedersen A, Hermetter A, Basu S, Hansen M, Haren
GR, Kall M, Breinholt V, Castenmiller JJ, Stagsted J, Jakobsen J,
Skibsted L, Rasmussen SE, Loft S, Sandström B. The 6-a-day study:
effects of fruit and vegetables on markers of oxidative stress and
antioxidative defense in healthy nonsmokers. Am J Clin Nutr
2004;79:1060-72.
49. McKay DL, Chen CY, Yeum KJ, Matthan NR, Lichtenstein AH,
Blumberg JB. Chronic and acute effects of walnuts on antioxidant
capacity and nutritional status in humans: a randomized, cross-over
pilot study. Nutr J 2010;9:21.