Glycative Stress Research
Online edition : ISSN 2188-3610
Print edition : ISSN 2188-3602
Received : May 2, 2024
Accepted : June 14, 2024
Published online : June 30, 2024
doi:10.24659/gsr.11. 2_71

Original article

Effects of ingesting food containing auraptene on lipid and glucose metabolism
Hiroshige Kawai 1), Kenta Fujimoto 1), Eiji Yuasa 1), Junichi Takimura 1), Yoshitaka Iwama 2)
1) Karada Lab, Inc. (Arkray Group), Kyoto, Japan
2) Nihonbashi Cardiology Clinic, Tokyo, Japan

Abstract

Objectives: Hassaku (Citrus hassaku) contains higher levels of auraptene in its rind compared to other citrus fruits.
Auraptene has been reported to potentially have various health benefits in both in vitro and in vivo studies. We conducted an
exploratory study of the effects of auraptene on humans at risk of metabolic syndrome using fractions of oil squeezed from
Hassaku fruits, which contain high concentrations of auraptene.
Methods: The participants were 14 adult men with an abdominal circumference of 85 cm or more and low-density
lipoprotein-cholesterol (LDL-C) of 140 mg/dL or more. The participants were randomly divided into 2 groups of 7 each.
The test food was Hassaku oil extract in the form of soft capsules, which was administered as auraptene (10 or 20 mg/day,
respectively) for 12 consecutive weeks. The participants underwent clinical examinations, physical examinations, blood andurine tests before ingestion, and at 6 weeks and 12 weeks after ingestion.
Results: In the 10 mg/day group (n = 7), a significant decrease from pre-ingestion to 12 weeks after ingestion was observed
as follows: Total cholesterol: 233.7 ± 34.7 mg/dL → 218.3 ± 28.4 mg/dL (p = 0.038, t-test), Insulin: 13.17 ± 4.41 → 9.76 ±3.71 μU/mL (p = 0.022, t-test). The 20 mg/day group (n = 7) also showed the same tendency of variation, but it was not
significant.
Conclusions: In the 10mg/day group, the ingestion of high-auraptene Hassaku oil extract improved lipid and glucose
metabolism, which suggested the contribution to the effectiveness in prophylaxis and prevention of progression of metabolic
syndrome and arteriosclerosis, and suppression of glycative stress.

KEY WORDS: auraptene, Citrus hassaku, lipid metabolism, total cholesterol, insulin resistanceIntroduction
Hassaku (Citrus hassaku), which has been widely
consumed in Japan for a long time, contains higher levels ofauraptene (a type of coumarin, Fig. 1) in its rind comparedto other citrus fruits 1). Auraptene has been reported to havevarious beneficial effects such as maintenance of cognitive
function 2), anticancer effects 3), improvement of muscular
endurance 4), heat stroke prevention 5), anti-Helicobacter pylori
effects 6), and improvement of non-alcoholic fatty liver disease(NAFLD) 7). In terms of lipid and glucose metabolism related
to anti-metabolic syndrome, auraptene has been reported
to activate the peroxisome proliferator-activated receptors(PPAR)-α and PPAR-γ. Auraptene increased adiponectinby acting on PPAR-γ in mouse precursor adipocyte 3T3-L1
and decreased monocyte chemoattractant protein (MCP)-1 8).

Fig.
1. Auraptene.
!"#$%&$%!"#$%&'('In the hepatocyte cell line HepG2, auraptene increased the
enzymes (acyl-CoA oxidase, carnitine palmitoyltransferase
1A, and acyl-CoA synthetase) of the target gene of PPAR-α,and accelerated the uptake of fatty acid to hepatocyte cells 9).
Auraptene was administered to diabetic and obese model
mice (KK-Ay ) fed with a high-fat diet. As a result, a decreasein the levels of triglycerides and free fatty acids in the blood,

Contact Address: Hiroshige Kawai
Karada Lab, Inc. (Arkray Group)
8 Nishiyama-cho, Higashi-kujo, Minami-ku, Kyoto 601-8046 Japan
TEL: +81-50-5830-1040 Fax: +81-75- 671-6060 e-mail: kawaih@arkray.co.jp
Co-authors: Fujimoto K, fujimoto.il@arkray.co.jp;
Yuasa E, yuasa.al@arkray.co.jp: Takimura J, takimura.td@arkray.co.jp;
Iwama Y, yiwama@well-sleep.jp_ 71 _

Glycative Stress Research 2024; 11 (2): 71- 78(c) Society for Glycative Stress ResearchEffects of Auraptene Consumption on Lipid and Glucose Metabolism

inhibition of the accumulation of triglycerides in the liver
and the skeletal muscles, an increase in mRNA expression
levels of adiponectin in adipocytes, and improvement ofhyperglycemia and abnormal glucose tolerance inducedby the high-fat diet were observed 10). Meanwhile, in thecase of administration of auraptene to Otsuka Long-Evans
Tokushima fatty (OLETF ) rats, a type 2 diabetes model
animal, the weight of visceral white adipose tissue and thelevels of liver triglycerides dose-dependently decreased 11).
On the other hand, not only do the reactive dicarbonyls
methylglyoxal, 3-deoxyglucosone, and glyoxal increase in
the serum of diabetic patients along with blood glucose
levels due to abnormalities in glucose metabolism, but also
the peroxidation of fatty acids can lead to the productionof numerous dicarbonyls including malondialdehyde and
4-hydroxynonenal, suggesting that abnormalities in lipid
metabolism may also be involved in the enhancement ofglycative stress 12, 13).
Based on these prior studies, we conducted a 2-dose
clinical trial of auraptene as a pilot study.

Methods
ParticipantsParticipants were paid volunteers selected from 39
participants (enrolled in e-Kencom corporation, Tokyo, Japan)
who underwent screening prior to the start of test foodingestion. The exclusion criteria were set to exclude persons
in the state such as taking medication for an illness andregularly consuming healthy foods containing auraptene. In
accordance with the inclusion criteria, 14 men aged between
4 0 and 64 with an abdominal circumference of 85 cm or more
and low-density lipoprotein-cholesterol ( LDL- C) of 14 0
mg/dL or more were selected. The allocation manager ( TTC
Co., Ltd., Tokyo), who was not directly involved in this study,
randomly assigned 14 participants to a 10 mg/day group anda 20 mg/day group so that there would be no inter-groupimbalances of LDL-C (calculated), body weight, and bodymass index (BMI). The allocation table was sealed by theallocation manager and was kept sealed until it was opened.
After analysis sets and data were fixed, a person in charge ofallocation opened the allocation table and disclosed theinformation. Since this study was conducted as an exploratory
dose-finding study, 6 participants per group needed to beensured, so taking dropouts into account, the number ofparticipants in this study was set to be 7 per group.

Test Food

The auraptene was formulated using Hassaku oil extract(Product name: Rapten, Karada Lab, Inc., Kyoto, Japan). The
concentration of auraptene in this product is specified to beat least 80 %. The test food consisted of 2 doses of auraptene,
10 mg/day and 20 mg/day, in the form of soft capsules thatare indistinguishable by taste, flavor, color, and other features.
Each of the soft capsules were designed such that 3 capsules
would provide daily intake per day. The nutritional constituentsof the test food are shown in Table 1.

Table 1. Test food nutritional constituents(Administration amount per day: per 3 capsules).

EnergyProtein
Lipid
Carbohydrate
SodiumTrial Design

Auraptene
10 mg/day

Auraptene
20 mg/day

8.9 kcal
0.3 g
0.8 g
0.1 g
0.002 g

8.9 kcal
0.3 g
0.8 g
0.1 g
0.002 gThis study was conducted as a randomized, doubleblind, parallel-group study of 2 dose levels with no placebo
control. The participants were instructed to consume 3
capsules of the test food (10 mg/day or 20 mg/day) basicallyafter meal once a day for 12 weeks, and underwent physicalmeasurement and examination, blood and urine tests,
medical interviews, and lifestyle surveys. All tests wereconducted 3 times in total, prior to administration and at 6
and 12 weeks after administration. The participants wereprohibited from drinking alcohol and had to finish meals by
10:00 p.m. on the day before their clinic visit, after which,they were instructed to fast, except for drinking water, until
the completion of the testing.
The primary endpoints were high molecular weightadiponectin, total adiponectin, and high molecular weight/
total adiponectin ratio. Secondary endpoints were LDL-C,
high-density lipoprotein-cholesterol (HDL-C), totalcholesterol (TC), non-HDL cholesterol (non-HDL- C ),LDL-C/HDL-C ratio (L/H ratio), arteriosclerosis index,
triglycerides, free fatty acids, fasting blood glucose,
HbA1c, insulin (immunoreactive insulin), and HOMA-IR(homeostatic model assessment for insulin resistance). LDL-C
was calculated using the Friedewald equation as a calculation
method, and in the case where triglycerides is 400 mg/dL
or more, the LDL-C direct method was used. But all results
were measured by the calculation method.
Additional safety endpoints included body weight, BMI,
abdominal circumference, hip circumference, waist/hip ratio,
systolic blood pressure, diastolic blood pressure, pulse rate,
white blood cell count, red blood cell count, hemoglobin,
hematocrit, MCV (mean corpuscular volume), MCH (meancorpuscular hemoglobin), MCHC (mean corpuscular hemoglobin
consentration), platelet count, white blood cell differential,
total bilirubin, alanine aminotransferase (ALT [glutamic
pyruvate transaminase; GPT]), aspartate aminotransferase(AST [glutamic oxaloacetic transaminase; GOT]), LDH(lactate dehydrogenase), γ-GTP (glutamyl transpeptidase),
ALP (alkaline phosphatase), CPK (creatine phosphokinase),
total protein, albumin, A/G ratio, uric acid, urea nitrogen,creatinine, Na, K, Cl, Ca, Fe, C-reactive protein (CRP),
high-sensitivity CRP, and urinalysis (specific gravity, pH,urobilinogen, bilirubin, ketone body, protein, glucose, occult
blood, white blood cell, and nitrites). The medical interviews
were conducted by a physician.
The participants recorded their ingestion status of thetest food (time of ingestion), changes in their body conditions(adverse event survey), presence or absence of changes in_ 72 _Glycative Stress Research

lifestyles, administration status of medication and supplements,
a simplified dietary survey, and exercise status in each diary.
Separately, the participants also recorded dietary contents
and step counts (by pedometer) for 3 weekdays prior to eachexamination.
The duration of ingestion was from May 9 to August
6, 2011. Medical history interviews by the physician, bodymeasurements, blood sampling, and urine sampling wereconducted at Nihonbashi Cardiology Clinic (Tokyo).

Clinic), and were reviewed and approved on April 7, 2011.
Written informed consent was obtained from the participantsprior to the screening tests, and the participants sufficiently
understood the contents of the study plan and voluntarily
expressed their willingness to participate in the study bysubmitting the consent form.

Safety of auraptene

Analysis Set

Regarding the safety of auraptene, there are experienceswith eating foods (marmalade, candied fruit, etc.) using
the peel of Hassaku. Acute and subacute toxicity studies
of oral administration of auraptene in rats were conducted.
Acute administration of auraptene in doses of 125 ~ 2,000
mg/kg body weight had no mortality or clinical signs in aperiod of two days. To evaluate subacute toxicity, auraptene
was administrated for 28 days by oral gavage in dosesof 125 and 250 mg/kg, with no observed hematological,
histopathological, or biochemical modifications 14). In aclinical trial, no significant changes were observed in anyof the blood biochemical parameters during the trial due tointake of the test juice containing 6.0 mg of auraptene perday, and no adverse effects that could be attributed to the test
juice were observed 2).

Testing Method

Physical measurements included height, weight, bloodpressure, pulse rate, abdominal circumference, and hip
circumference, as well as body fat percentage by bioelectrical
impedance analysis. Blood and urine tests were performed at
the Japan Institute for the Control of Aging, Nikken Seil Co.,
Ltd. (Shizuoka, Japan).

Statistical Analysis

Measurements were presented as mean ± standard
deviation. Statistical analysis was performed using Microsoft
Excel 2007 (Microsoft Corporation). The amount of variationfrom pre-ingestion to the 12th week of the ingestion wascompared between groups using a 2-sample t-test. Also,
measurement values of pre-ingestion and post-ingestion
for each group were assessed using a 1-sample t-test with
Bonferroni correction. All significance levels were set at arisk rate of less than 5 % with a 2-tailed test.

Ethical Standards

This study was conducted in accordance with the
ethical principles outlined in the Declaration of Helsinki
and Ethical Guidelines for Epidemiological Research(Notification of Ministry of Education, Culture, Sports,
Science and Technology/Ministry of Health, Labour andWelfare) as well as the study protocol. In order to protect
the human rights and the safety of the participants as wellas the reliability of the study data, the documents were
submitted in advance to Ethical Committee of Nihonbashi
Cardiology Clinic (Chairman of the Committee: Takayasu
Omura, the Assistant Director of Nihonbashi Cardiology

Results

The tracking flow diagram for the participants is shownin Fig. 2. Participant recruitment began on April 7, 2011. After
undergoing screening tests, 14 participants were randomly
assigned to either a 10 mg/day group or a 20 mg/day group(7 participants each) for participation in the main study. All
participants completed the study, and none dropped out. All
participants were included in the analysis, and none wereineligible. Baseline demographic and clinical characteristics
for each group are shown in Table 2.

Primary Endpoints

Changes in the primary endpoints including highmolecular weight adiponectin, total adiponectin, and highmolecular weight/total adiponectin ratio are shown in Table 3.
There were no significant inter-group differences in the postingestion variations for these 3 parameters. No significant
variation between pre-ingestion and post-ingestion wasobserved.

Secondary Endpoints

In the secondary endpoints, significant variations ora trend between pre -ingestion and post- ingestion wereobserved in the following 4 parameters ( Table 3 ).
1) Total cholesterol (TC)
TC in the 10 mg/day group showed a significant decrease
as follows: before ingestion: 233.7 ± 34.7 mg/dL → 12 weeks
after ingestion: 218.3 ± 28.4 mg/dL (p = 0.038, t-test). On theother hand, TC in the 20 mg/day group showed no significant
variations before and after ingestion. There were no significant
inter-group differences in the variations before and afteringestion. (Fig. 3)2) Non-HDL cholesterol (non-HDL-C)
Non-HDL-C in the 10 mg/day group showed a decreasing
trend as follows: before ingestion: 176.7 ± 29.0 mg/dL → 12
weeks after ingestion: 164.9 ± 24.0 mg/dL (p = 0.067, t-test).
On the other hand, non-HDL-C in the 20 mg/day group
showed no significant variations before and after ingestion.
There were no significant inter-group differences in thevariations before and after ingestion. (Fig. 3)
3) Insulin
Insulin in the 10 mg/day group showed a significant
decrease as follows: before ingestion: 13.2 ± 4.4 μU/mL →12 weeks after ingestion: 9.8 ± 3.7 μU/mL (p = 0.022, t-test).
On the other hand, insulin in the 20 mg/day group showed nosignificant variations before and after ingestion. There wereno significant inter-group differences in the variations before
and after ingestion. (Fig. 4 )_ 73 _

Effects of Auraptene Consumption on Lipid and Glucose Metabolism

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Fig. 2. Tracking flow diagram for trial participants.

!"#$%&$%!"#$%&'()*+,-).&#("#/)*,")0"&#+)1#"0&$&1#'023
Table 2. Baseline demographic and clinical characteristics.
Unit
No. of participants(male : female)

Auraptene 10 mg /day

Auraptene 20 mg/day

p-value (t-test)

7 (7 : 0)

7 (7 : 0)–Ageyears of age

53.4 ± 7.3

53.1 ± 8.1

p = 0.94

Heightcm

169.3 ± 6.0

168.0 ± 6.3

p = 0.70

Weightkg

73.3 ± 7.0

72.6 ± 5.0

p = 0.83

BMI

kg/m2

25.5 ± 1.6

25.7 ± 1.5

p = 0.82

LDL cholesterol

mg/dL

147.3 ± 27.5

148.0 ± 27.5

p = 0.97

Total cholesterol

mg/dL

233.7 ± 34.7

233.7 ± 38.9

p = 0.83

Triglycerides

mg/dL

147.0 ± 20.7

143.7 ± 51.5

p = 0.88

μU/mL

13.2 ± 4.4

8.3 ± 2.7

p = 0.027*

3.26 ± 1.09

2.01 ± 0.76

p = 0.028*

Insulin
HOMA-IR* There were coincidental inter-group differences. Measured value: mean ± standard deviation. BMI, body mass index; HOMA-IR, Homeostatic Model
Assessment for Insulin Resistance.

_ 74 _Glycative Stress Research

Table 3. Primary and secondary endpoints.
Parameter

Unit

Reference Group
range(/day)

n

0W

6W

12 W

10 mg

7

8.86 ± 3.55

–

20 mg

7

7.01 ± 2.61–

8.53 ± 3.46

10 mg

7

2.76 ± 1.57

–

20 mg

7

1.99 ± 1.03

–

10 mg

7

0.277 ± 0.102

–

20 mg

7

0.272 ± 0.051

–

10 mg

7

147.3 ± 27.5

144.1 ± 27.6

20 mg

7

148.0 ± 27.5

10 mg

7

57.0 ± 10.9

20 mg

7

57.0 ± 12.3

10 mg

7

233.7 ± 34.7

20 mg

7

233.7 ± 38.9

10 mg

7

176.7 ± 29.0

20 mg

7

176.7 ± 29.4

10 mg

7

2.63 ± 0.50

20 mg

7

2.64 ± 0.45

10 mg

7

3.16 ± 0.59

20 mg

7

3.16 ± 0.52

10 mg

7

147.0 ± 20.7

20 mg

7

143.7 ± 51.5

10 mg

7

0.801 ± 0.222

20 mg

7

1.050 ± 0.362

10 mg

7

100.9 ± 9.7

20 mg

7

97.4 ± 7.3

10 mg

7

20 mg

7

10 mg

7

20 mg

7

10 mg

7

20 mg

7

Primary Endpoints
Total adiponectin

μg/mL

–

High molecularadiponectin

μg/mL

–

High molecular weight /total adiponectin ratio–

Secondary endpoints

Lipid
metabolism

Glucosemetabolism

LDL cholesterol

mg/dL

70 -139

HDL cholesterol

mg/dL

40 - 77

Total cholesterol

mg/dL

130 - 219

Non-HDL cholesterol

mg/dL

< 170

L/ H ratio< 2.5

Arteriosclerotic index< 2.5

Triglycerides

mg/dL

Free fatty acids

mEq/L 0.10 - 0.90

Fasting glucose

mg/dL

70 -109%

4.3 - 5.8

μU/mL

1.7 - 11.8

Hemoglobin A1c (JDS)
Insulin ( IRI)
HOMA-IR

40 -149< 2. 5

6.99 ± 2.69

2.71 ± 1.57
2.03 ± 1.31

0.289 ± 0.091
0.272 ± 0.057
135.1 ± 23.4

55.6 ± 11.3

133.9 ± 26.1
53.4 ± 9.4 #226.1 ± 36.0

218.3 ± 28.4 #

170.6 ± 29.0

164.9 ± 24.0 †2.62 ± 0.38

2.57 ± 0.52

149.2 ± 18.2
53.3 ± 8.9

230.7 ± 25.4
177.4 ± 24.4

2.86 ± 0.54
3.13 ± 0.58
3.42 ± 0.73

54.4 ± 9.6

221.1 ± 24.9

166.7 ± 21.8

2.52 ± 0.59
3.14 ± 0.56
3.14 ± 0.62

132.3 ± 63.1

148.7 ± 72.9

0.803 ± 0.181

0.874 ± 0.299

141.3 ± 64.4

0.869 ± 0.265

163.9 ± 84.6

1.003 ± 0.322

99.0 ± 10.9

100.4 ± 11.0

5.07 ± 0.20

5.13 ± 0.32

5.10 ± 0.31

13.2 ± 4.4

11.7 ± 3.3

3.26 ± 1.09

2.87 ± 0.96

4.86 ± 0.22
8.3 ± 2.7

2.01 ± 0.76

99.1 ± 5.9

4.86 ± 0.31
7.6 ± 1.8

1.87 ± 0.47

97.4 ± 8.5

4.83 ± 0.22

9.8 ± 3.7 #6.9 ± 2.5

2.44 ± 0.98 #1.66 ± 0.61

All male. Measured value: mean ± standard deviation. No significant differences were observed in inter- group comparison. # p < 0.05, † p < 0.1: Comparison
with pre-ingestion (1-sample t - test with Bonferroni correction). L /H ratio, LDL cholesterol / HDL cholesterol ratio; JDS, The Japan Diabetes Society;
HOMA- IR, Homeostatic Model Assessment for Insulin Resistance.

_ 75 _

Effects of Auraptene Consumption on Lipid and Glucose Metabolism

p = 0.038
250

200

150

0 weeks250

Non-HDL cholesterol (mg/dL)

Total cholesterol (mg/dL)

300

10 mg group (n = 7)

p = 0.067

12 weeks

200

150

100

20 mg group (n = 7)

6 weeks

10 mg group (n = 7)

20 mg group (n = 7)

Fig. 3. Changes in total cholesterol and non-HDL cholesterol.

Measured value: mean ± standard error of the mean. Analysis: 1-sample t-test with Bonferroni correction (intra-group) and 2 -sample
t- test ( inter- group).

20

0 weeks5
p = 0.016

15

4

HOMA - IR

Insulin (IRI : µU/mL)

p = 0.022

10

5

0

6 weeks
12 weeks32

10 mg group (n = 7)1

20 mg group (n = 7)

10 mg group (n = 7)

20 mg group (n = 7)

Fig. 4. Changes in insulin (IRI) and HOMA-IR.

Measured value: mean ± standard error of the mean. Analysis: 1-sample t- test with Bonferroni correction (intra-group) and 2-samplet - test (inter-group). HOMA-I R, homeostatic model assessment for insulin resistance.

4) HOMA-IR
HOMA-IR in the 10 mg/day group showed a significant
decrease as follows: before ingestion: 3.26 ± 1.09 → 12 weeks
after ingestion: 2.44 ± 0.98 (p = 0.016, t-test). On the other
hand, HOMA-IR in the 20 mg/day group showed no significant
variations before and after ingestion. There were no significant
inter-group differences in the variations before and afteringestion. (Fig. 4 )Safety Endpoints

hematology, urinalysis, physical examination, or medical
interview, there were no abnormalities or abnormal variations
that might be caused by the ingestion of the test food. The
physician determined that there were no safety issues.

Discussion

Primary endpoints

Adverse event occurrence based on participants’ diaries
and variations in clinical laboratory values were investigated.
The adverse events of “ lumbosacral strain”, “common cold
symptom”, “abdominal pain” and “periodontal disease”
occurred in 1 participant each, but these events disappeared
shortly or were temporary changes. In blood biochemistry,In this study, no significant changes in adiponectinrelated indicators, the primary endpoints were observed.
However, in diabetic obese KK-Ay mice, significant increases
in mRNA expression levels of adiponectin in adipose tissues
and adiponectin protein levels in plasma were observed 10).
The possible causes of these results were that the doses per
body weight in the mice were approximately 500 to 1000-_ 76 _Glycative Stress Researchfold greater that used in this study method and there was aspecies difference.

indicate that intake of auraptene 10 to 20 mg/day improves
lipid and glucose metabolism.

Secondary endpoints

Alleviation of glycative stress by test foods

In the secondary endpoints, TC, insulin, and HOMA-IR
significantly improved in the 10 mg/day group, and there wasa trend towards improvement of non-HDL-C. On the other
hand, in the 20 mg/day group, there were no significant or
trending variations. Thus, dose dependency was not observed.
As the reason for this, it was considered that there wereincidental inter-group differences for insulin and HOMA-IR( Table 2 ). In accordance with the protocol, group matching
was performed on LDL-C, body weight, and BMI, but insulin
was not taken into account. More participants with higher
insulin resistance were assigned to the 10 mg/day group,
which led to greater improvement of insulin resistance dueto the effects of auraptene (Fig. 4 ). As a result, it was thoughtthat further improvement in cholesterol metabolism had been
observed. The reason was that in diabetic and obese model
mice ( KK-Ay ) fed with high-fat food, auraptene contributed
to the increase in the expression of PPAR-α target genesthat are related to fatty acid oxidation in the liver and theskeletal muscle 10), activation of PPAR-α improved insulin
resistance 15), and the improvement of insulin resistance led tocholesterol improvement 16). These were considered to be oneof the mechanisms. In addition, in the experiments on obese
adipose tissue models using the co-culture system of 3T3-L1
adipocyte and RAW264 macrophage, auraptene suppressed
the production of inflammatory factors 17), which suggested
a contribution to the alleviation of chronic inflammationand improvement of insulin resistance. Furthermore, it wasinferred that glycative stress is suppressed through this insulin
resistance improvement.

HDL cholesterol

In the 10 mg/day group, HDL-C significantly decreased(57.0 → 53.4 mg/dL, p = 0.023). However, there were no
participants whose HDL-C decreased below the lower limitof the reference range, but the variation was relatively small
within the range. LDL transports cholesterol produced in theliver throughout the body, and HDL has the role of collecting
unnecessary cholesterol from tissues and transporting it backto the liver. When LDL-C increases, HDL-C may increasein compensatory fashion to maintain homeostasis. Since
non-HDL- C , which was high before the test food intake,tended to decrease by the intervention, it is believed thatthe compensatory increase in HDL-C was reduced. This is
supported by the fact that there was no change in the L/Hratio. Therefore, it was thought that there were no clinicalabnormalities in the balance of lipid metabolism.

Combining the both groups

In this study, since there were only 7 participants pergroup, the 2 groups were combined and tested as a trial
calculation. As a result, a significant decrease was observedin LDL-C, TC, insulin, and HOMA-IR, with a decreasing
trend in non-HDL- C (data not shown). From this, it wasthought that the 20 mg/day group also has the potential for
improvement in the aforementioned parameters, and it may

It has been suggested that not only carbohydratederived aldehydes generated following hyperglycemia 18) but
also fatty acid-derived aldehydes 12, 13) play pathogenic rolesin the effects of glycative stress on the body. These aldehydes
modify proteins in blood vessels and cells in unphysiologicalmanners. In pancreatic beta cells, insulin biosynthesis isaffected by aldehyde modification, inhibiting the conversion
of proinsulin to insulin. As a result, the proportion of
inactive proinsulin increases and the proportion of active
insulin decreases in immune-reactive insulin (IRI), which
may increase insulin resistance 19). It can be assumed that bylowering LDL-C, this test food reduced the production of
fatty acid-derived aldehydes, reduced the effect of aldehydes
on insulin biosynthesis in pancreatic beta cells, and increased
the proportion of active insulin in the IRI. As a result, it ispresumed that insulin activity was maintained even though
the IRI value decreased, and the HOMA-Index (insulin
resistance) improved. We plan to verify in the future whether
this test food reduces fatty acid-derived aldehydes.

Conclusions
A study was conducted on males with an abdominal
circumference of 85 cm or more and LDL-C of 140 mg/dL
or more who took 10 or 20 mg/day of auraptene for 12
weeks. The findings suggested that food containing Hassaku
oil extract improves lipid and glucose metabolism via theeffects of auraptene in the 10 mg/day group. These wereconsistent with the reported in vitro and in vivo studies,indicating that they may be effective in humans through asimilar mechanism. From this fact, auraptene is expected tobe effective in the prophylaxis and prevention of metabolic
syndrome and arteriosclerosis, and suppression of glycative
stress. Additionally, high safety was confirmed even for casesof continuous ingestion.

Conflict of Interest Declaration
This study was fully funded by Arkray, Inc. andoutsourced and conducted by TTC Co., Ltd. (currently, EP
Mediate Co., Ltd.), a third-party organization. Hiroshige
Kawai, Kenta Fujimoto, Eiji Yuasa, and Junichi Takimura
are employees of Karada Lab, Inc., a subsidiary of Arkray
Corporation. Yoshitaka Iwama is the principal investigatorof this study at Nihonbashi Cardiology Clinic. There are noother conflicts of interest to disclose relevant to this article.

Funding_ 77 _

No funding was received for conducting this study.

Effects of Auraptene Consumption on Lipid and Glucose Metabolism

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