Glycative Stress Research
Online edition : ISSN 2188-3610
Print edition : ISSN 2188-3602
Received : July 12, 2014
Accepted : August 15, 2014
Published online : September 30, 2014

Original Artcle

Anti-glycation effect of pomegranate (Punica granatum L.) extract:
An open clinical study
Masayuki Yagi 1), Lanny Parengkuan 1), Haruhi Sugimura 2), Nobuhiko Shioya 3),
Yoichi Matsuura 4), Norihisa Nishida 4), Akifumi Nagatomo 4), Yoshikazu Yonei 1),
1) Anti-Aging Medical Research Center and Glycation Stress Research Center, Graduate School of Life and Medical Sciences,
Doshisha University, Kyotanabe, Kyoto, Japan2) Medical Corporation Shinkokai C'est La Vie Shinbashi Clinic, Minato-ku, Tokyo, Japan
3) KSO Co., Ltd., Minato-ku, Tokyo, Japan
4) Morishita Jintan Co., Ltd., Chuo-ku, Osaka, Japan

Abstract

Objective: The purpose of the present study is to elucidate the effect of pomegranate (Punica granatum L.) extracts on
glycation stress reduction in an open clinical study without control subjects.

Methods: Subjects were 10 post-menopausal females (aged 58.5 ± 3.9) who received oral administration of 100mg/day

pomegranate extract (PE) for 12 weeks. At 0, 8 and 12 weeks the following glycative stress markers were analyzed: blood
glucose, HbA1c, glycoalbumin, 3-deoxyglucosone (3DG), N ε-(carboxymethyl) lysine (CML), pentosidine, and skin fluorescencefrom advanced glycation end products (AGEs).
Results: HbA1c significantly was decreased at 8 and 12 weeks after PE administration. Glycoalbumin, 3DG and pentosidine
showed significant reduction at 8 weeks, but not at 12 weeks. Serum CML increased at 12 weeks. No changes were noted in skinfluorescence AGEs intensity and skin elasticity. No severe adverse effect was observed during the test period.
Conclusions: The 12-week oral administration of PE to healthy menopausal females showed a decrease in the glycative stressmarkers, indicating the potential effect of PE in reducing glycative stress.

KEY WORDS: glycative stress, pomegranate (Punica granatum L.), advanced glycation end products (AGEs),
3-deoxyglucosone (3DG), N ε-(carboxymethyl) lysine (CML), pentosidine.

Introduction

Glycation reaction, also called the Maillard reaction after
the chemist who discovered the reaction, is a non-enzymatic
irreversible reaction between reducing sugars and protein,
finally generating advanced glycation end products (AGEs).
AGEs are associated with the progression of diabetes and aging,and have been recently considered as a risk factor for agerelated diseases and aging 1, 2) .
In our previous study on the inhibitory effects of various
fruits, a high anti-glycation activity was found in pomegranate(Punica granatum L.) extract (PE) 3 ). Using the glycation
model kit between collagen and glucose, the activity of PE
was proven to be 3 fold that in other fruits which are reported
to have anti-glycative activity 4). Since it will be important toexamine the anti-glycation effect in humans, we undertook thepresent study to elucidate the anti-glycative effect of PE in an
open clinical pilot study without control subjects.

Methods
Subjects

Subjects were 10 post-menopausal healthy females (aged
30 to 60 years old, 58.5 ± 3.9 years), with body mass index(BMI) of 22.3 ± 3.2 from who informed consent and written
permission was obtained before participation. Persons withthe following criteria were excluded:1) Persons who have diabetes, renal dysfunction or a historyof gastrointestinal surgery.
2) Persons taking anti-oxidative drugs or medications.
3) Persons not considered to be qualified by the responsible
medical doctor.

Address correspondence to: Yoshikazu Yonei MD, PhD
Anti-Aging Medical Research Center/ Glycation Stress Research Center,
Graduate School of Life and Medical Sciences Doshisha University
1-3 Tatara-Miyakodani, Kyotanabe, Kyoto 610-0321, Japan
Tel & FAX: +81-774-65-6394 / E-mail: yyonei@mail.doshisha.ac.jp
Co-authors: Yagi M, myagi@mail.doshisha.ac.jp Parengkuan L, lannyparengkuan@ymail.com
Sugimura H, h-sugimura@shinkokai.jp Shioya N, shioya@kso.co.jp Matsuura Y, y-matsuura@jintan.co.jp
Nishida N, nishida@jintan.co.jp Nagatomo A, a-nagatomo@jintan.co.jp_ 60 _

Glycative Stress Research 2014; 1 (3): 60-67(c) Society for Glycation Stress ResearchGlycative Stress Research

Table 1. Test product profile.

Study design

Test productIn this study, an open pilot study without control subjects,
the subjects orally took 2 capsules per day, once a day for 12
weeks for a daily PE amount of 100 mg.
Before the study (0W), at 8 weeks (8W) and 12 weeks
after the study (12W ), the subjects underwent the following
examinations: Anti-Aging QOL (quality of life) Common
Questionnaire (AAQol) test, physical tests (blood pressure,pulse count, body weight and BMI), blood biochemistry
tests [fasting plasma glucose (FPG), immune reactive insulin(IRI), HbA1c, glycoalbumin, 3-deoxyglucosone (3DG),
N ε -(carboxymethyl)lysine (CML) and pentosidine], andmeasurement of skin fluorescence from AGEs.
For the evaluation of safety, the subjects underwent thefollowing examinations: peripheral blood tests (white blood cellcount, red blood cell count, hemoglobin, hematocrit, platelet
count, MCV, MCH, MCHC and white blood cell profile) andserum biochemistry tests [total protein,albumin, AST, ALT,
LDH, total bilirubin, ALP, γ-GTP, BUN, creatinine, uricacid, sodium, chloride, potassium, calcium, total cholesterol(TC), low-density-lipid-cholesterol (LDL-C), high-densitylipid-cholesterol (HDL-C), and triglyceride (TG)]. The safety
analyses will be documented in a subsequent report.
The subjects recorded, written in notes, about theirlifestyles, adverse effects, and compliance of test sample intake.
The study was conducted at Medical Corporation Shinkokai
C'est La Vie Shinbashi Clinic (Minato-ku, Tokyo, Japan)
during the period from November 1, 2012 to May 31, 2013.

Test product

The profile of the test product is presented in Table 1
and components in one capsule in Table 2. The test products
were provided by Morishita Jintan Co., Ltd. (Chuo-ku, Osaka,
Japan).

Examination items

Subjective symptoms and anthropometry

Physical and mental symptoms were recorded and rated
on a 5-grade scale using the Anti-Aging QOL Common
Questionnaire (AAQol) 5, 6). The following anthropometricparameters were recorded: height (cm), body weight (kg),blood pressure (systolic/diastolic: mmHg), pulse rate (pulse/min).

Blood chemistry

The glycative stress markers measured by bloodbiochemistry included fasting plasma glucose (FPG),
immune reactive insulin (IRI), HbA1c, glycoalbumin,
3-deoxyglucosone (3DG), CML and pentosidine. CML and3DG were measured at Fushimi Pharmaceutical Co., Ltd.
(Marugame, Kagawa, Japan). The rests were measured at LSI
Medience Corporation (Chiyoda-ku, Tokyo, Japan).

Skin AGEs auto-fluorescence

The amount of AGEs in a subject’s skin was measured
using an AGE Reader TM ( DiagnOptics, Groningen,
Netherlands) 7, 8). This is a non-invasive method detecting autofluorescence (AF) specific for fluorescent AGEs accumulated

Pomegranate extract-containing capsule
Lot.No.20121017

Lot number

2012/10/12

Production date

50 mg

Active ingredients per capsule
Active ingredients per day

100 mg/2capsile

Type

Hard capsules

Amount199.5 mg/capsule

Reserve condition

Room temperature
1 yearDate limit

Table 2. Ingredients in the test product per one capsule.
Ingredients

Test productAmount (mg/capsule)

Ratio (%)

Pomegranate extract

50.0

25.1

Cellulose

94.0

47.1

Silicon dioxide

3.0

1.5

Calcium stearate

3.0

1.5

Gelatin

48.0

24.1

Caramel color

1.5

0.7

199.5

100.0

Total

in the skin exited by ultra-violet ray 9, 10 ). According to
examinations of skin biopsy specimens from diabetic patientsand hemodialysis patients with chronic renal failure, skin
AF has been confirmed to be correlated with representative
AGEs, i.e., pentosidine, a fluorescent AGE, and CML, a nonfluorescent AGE 9, 10). In the present study, subjects were asked
to rest their elbow on the AGE Reader. Measurements were taken
at the outer upper right arm, 10 cm away from the edge of theelbow. After wiping the measuring area using a cotton swaband
alcohol, AF intensity was measured three times at the same
point, and the results were expressed as the mean of three values.

Skin elasticity test

Skin elasticity was evaluated using a Cutometer(MPA580; Courage & Khazaka Electronic, GmbH, Cologne,
Germany) 11, 12). Briefly, a probe was placed on the skin surfaceof the inner side of the right arm at 10 cm from the elbow, andan area of skin was drawn up into the probe using negative
pressure; the length of skin drawn into the probe was thenmeasured using a glass prism. The R2 index is the ratio of skinlength recovery after elongation and constriction (Ua1/Uf1),
indicating improvement in elasticity as the ratio approaches
1.00; an ideal elastic material has an R2 value of 1.00, andnormal skin has values in the range of 0.3 ~ 0.5. The R7 index
is a ratio of skin elasticity during constriction (Ur1/Uf1); themost elastic skin has an R7 value close to 1.00. The R2 and R7
indices are the most reliable indices derived from a Cutometer;a previous study found that these indices decrease with aging,with the curve shifted down and forward in patients withdiabetes mellitus 13). Skin elasticity was measured four times
to reduce error, with the highest and lowest values removed
before averaging calculations.

_ 61 _

Anti-Glycation Effect of Pomegranate Extract: an Open Clinical Study

Ethical standards

The trial followed the Japanese Ministry of Health andWelfare Ordinance No. 28 “Standards of implementation of
the clinical trial of a pharmaceutical" (March 27, Heisei 9)”
and was completed at a third-party medical institution (Medical
Corporation Shinkokai C'est La Vie Shinbashi Clinic, Minatoku, Tokyo, Japan). The trial was approved by the Ethics
Committee of the clinic and KSO Co., Ltd. (Minato-ku, Tokyo,
Japan).

Statistical analysis

Test results are expressed as the mean ± standard deviation(SD) of absolute values. Differences in variables between thestart (0W), and at eight (8W) and twelve weeks after (12W),
were tested by Wilcoxon rank sum test or by Dunnett’s test.
Statistics were calculated with Dr. SPSSII (IBM Japan, Chuoku, Tokyo), and the level of significance was set at < 5% (twotailed test).

Results
Mental and physical subjective symptoms in AAQol

All 10 subjects were qualified for the test protocol; nosubject dropped out, and all were analyzed. In 34 items of thephysical symptoms, no score was significantly improved at
12 weeks after PE intake ( Table 3 ). In contrast, the “blurryeyes” score changed from 0W; 1.6 ± 0.7 to 12w;2.5 ± 0.5 (p= 0.016), “palpitation” score from 0W; 1.4 ± 0.5 to 12W; 2.0± 0.5 (p = 0.031). Precise examination of the individual cases
revealed that no subject claimed the symptoms of “blurry eye”
or “palpitation” as adverse effects. In the 21 items of mental
symptoms, significant changes were not noted in the score( Table 4 ).

Blood biochemistry

The results of blood glycative stress markers are presented
in Table 5. During the 12-week observation period with oral PE

Table 3. Physical subjective symptom score in AAQol.
Parameter
Tired eyes

Blurry eyes
Eye pain

Stiff shoulders

Muscular pain/stiffness
Palpitations

Shortness of breath

Tendency to gain weight
Weight loss; thin
Lethargy

No feeling of good healthThirstSkin problems
Anorexia

Early satiety

Epigastralgia

Liable to catch colds

Coughing and sputum
Diarrhea

Constipation
Hair loss

Gray hair

HeadacheDizziness
Tinnitus

Hearing difficulty
LumbagoArthralgia

Edematous

Easily breaking into a sweat
Frequent urination
Hot flashCold skin

mean
2.20
1.60
1.20
2.50
1.80
1.40
1.70
2.30
1.40
2.00
1.80
1.60
1.80
1.50
1.70
1.50
1.80
1.80
1.50
2.20
2.20
3.60
1.60
1.20
1.70
1.70
2.20
1.80
1.40
2.10
2.10
1.40
2.50

0W
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±

SD

1.03
0.70
0.42
1.35
0.79
0.52
0.82
1.42
0.52
1.05
0.92
0.84
0.42
0.53
0.67
0.71
0.79
0.79
0.53
1.03
0.79
0.97
0.70
0.42
1.06
0.82
0.79
0.92
0.52
0.99
0.88
0.52
0.85

mean
2.20
2.10
1.50
2.60
2.10
1.70
1.90
2.30
1.50
2.10
2.00
2.10
2.00
1.80
1.80
1.80
2.20
1.70
1.60
2.40
2.50
4.00
1.70
1.30
1.90
2.00
2.50
1.70
1.50
2.50
2.50
1.50
2.90

±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±

8W
SD

0.79
0.99
0.53
1.35
0.99
0.48
0.57
1.42
0.53
0.99
0.47
0.99
0.67
0.63
0.79
0.63
0.79
0.82
0.52
0.97
1.08
0.82
0.67
0.48
1.29
0.82
1.35
0.67
0.71
1.08
0.97
0.53
1.37

p value
1.000
0.313
0.250
1.000
0.500
0.250
0.750
1.000
1.000
1.000
0.727
0.250
0.500
0.375
1.000
0.250
0.125
1.000
1.000
0.500
0.250
0.125
1.000
1.000
0.625
0.250
0.531
1.000
1.000
0.500
0.289
1.000
0.313

mean
2.50

±

1.70

±

2.50
2.70
2.30
2.00
2.10
2.60
1.90
2.00
2.10
2.30
2.00
1.60
2.00
2.00
2.00
2.30
1.70
2.50
2.80
3.70
1.90
1.70
2.20
2.20
2.50
2.10
1.70
2.10
2.70
1.70
3.00

*p < 0.05, vs.0W, n = 10, by Dunnet's Wilcoxon test. AAQol, Anti-Aging QOL Common Questionnaire; SD, standard deviation.

_ 62 _

±

±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±

12 W
SD

p value

0.71

0.563

0.48

0.063

0.53
1.34
0.95
0.47
0.57
1.17
0.99
0.67
0.88
0.82
0.82
0.52
0.94
0.67
0.67

0.016*
0.625
0.250

0.031*
0.344
0.375
0.375
1.000
0.375
0.109
0.688
1.000
0.250
0.063
0.500

0.82

0.125

0.97

0.375

0.48
1.03
0.82
0.57
0.48
1.32
0.92
0.85
0.88
0.67
0.99
0.95
0.48
1.25

0.500
0.148
1.000
0.250
0.063

0.063
0.125
0.375
0.453
0.375
1.000
0.109
0.250
0.180

Glycative Stress Research

at 12W; 5.08 ± 0.98 μg/ml (p = 0.036, Fig. 5 ).

intake, IRI did not change significantly. HbA1c significantly
decreased from 0W; 5.73 ± 0.27%, to 8W; 5.56 ± 0.16% (p =0.001) and remained low to 12W; 5.53 ± 0.17% (p = 0.001,
Fig. 1 ). Glycoalbumin, 0W; 14.9 ± 0.7%, was significantly
lower at 8W; 14.2 ± 0.6% (p = 0.005), however, it was not
significant at 12W; 14.4 ± 0.5% (p = 0.054, Fig. 2 ). Similarly,
3DG, 0W; 24.19 ± 4.80 ng/mL, was significantly lower at 8W;
16.92 ± 2.14 ng/mL (p < 0.001), but not significant at 12W;
22.79 ± 5.30 ng/mL (p = 0.485, Fig. 3 ). Pentosidine showed
96.84 ± 18.25 pmol/mL at 0W and it was significantly lower at
8W; 83.66 ± 12.66 pmol/mL (p = 0.036), and then it returnedto the baseline at 12W; 106.12 ± 15.40 pmol/mL (p = 0.154,
Fig. 4 ). CML, 0W; 4.27 ± 0.54 μg/ml, was significantly higher

Skin AGEs auto-fluorescence

The amount of skin fluorescent AGEs was not significantly
changed by PE intake during the 12-week observation period( Table 6 ).

Skin elasticity test

PE showed no significant effect on index R2, R5, R6 andR7 of the skin elasticity test during the observation period( Table 6 ).

Table 4. Mental subjective symptom score in AAQol.
Parameter

mean

Irritability

1.90

Easily angered

1.60

Loss of motivation

1.80

No feeling of happiness

1.50

Nothing to look forward to in life

1.50

Daily life is not enjoyable

1.70

Lose confidence

1.70

Reluctance to talk with others

1.50

Depressed

1.40

Feeling of uselessness

1.70

Shallow sleep

2.30

Difficulty in falling asleep

1.50

Pessimism

1.70

Lapse of memory

2.60

Inability to concentrate

1.80

Inability to solve problems

1.80

Inability to make judgments readily

2.10

Inability to sleep because of worries

1.90

A sense of tension
Feeling of anxiety for no special reason
Vague feeling of fear

2.10
1.20
1.10

0W
±

SD

mean

±

±

0.74

2.00

±

0.52

1.90

0.42

1.80

0.53

1.50

0.53

1.50

0.48

1.40

0.48

1.60

0.71

1.70

0.52

1.50

0.67

1.80

1.25

2.30

0.71

2.00

0.67

2.10

0.70

2.80

0.63

2.30

0.42

2.10

0.74

2.20

0.74

2.20

0.99

1.80

0.42

1.70

0.32

1.20

±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±

8W

±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±

SD

p value

mean

±

0.82

1.000

2.00

±

0.57

0.375

2.00

0.63

1.000

2.00

0.71

1.000

1.60

0.53

1.000

1.80

0.52

0.250

1.50

0.70

1.000

1.80

0.95

0.500

1.80

0.71

1.000

1.70

0.42

1.000

1.80

0.82

1.000

2.40

1.05

0.063

2.20

0.99

0.219

2.30

0.63

0.625

3.00

0.48

0.125

2.40

0.74

0.375

2.20

0.79

1.000

2.30

0.79

0.375

2.00

0.63

0.500

2.20

0.48

0.063

1.50

0.42

1.000

1.30

±

±

±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±

12 W
SD

p value

0.67

1.000

0.67

0.313

0.94

0.766

0.70

1.000

0.92

0.750

0.53

0.625

0.63

1.000

0.63

0.250

0.67

0.250

0.42

1.000

0.84

0.984

1.23

0.031

0.67

0.063

0.82

0.313

0.52

0.125

0.63

0.250

0.82

0.625

0.67

1.000

0.63

1.000

0.53

0.250

0.48

0.500

p Value vs. 0W, n = 10,by Dunnett's Wilcoxon test. AAQol, Anti-Aging QOL Common Questionnaire; SD, standard deviation.

Table 5. Blood glycative stress markers.
Parameter

mean

0W
±

FPG (mg/dL)

86.3

±

IRI (mU/mL)

3.12

±

4.27

±

96.84

±

HbA1c (%)

Glycoalbumin (%)
CML (mg/mL)
3DG (ng/mL)

Pentosidine (pmol/mL)

5.73

±

14.9

±

24.19

±

±

SD

mean

6.5

83.8

±

1.06

2.79

±

4.87

±

83.66

±

0.27
0.7

0.54
4.80

18.25

5.56

±

14.2

±

16.92

±

8W
SD

p value

mean

5.9

0.130

87.6

±

1.20

0.408

3.63

±

5.08

±

0.16
0.6

0.76
2.14

12.66

0.001**
0.005**
0.133＜0.001**0.036*

5.53

±

14.4

±

22.79

±

106.12 ±12 W
SD

p value

6.4

0.523

0.88

0.148

0.98

0.036*

0.17 ＜0.001**
0.5

5.30

15.40

*p < 0.05, **p < 0.01 vs. 0W, n = 10, by Dunnett’s test.
FPG, fasting plasma glucose; IRI; immune reactive insulin; 3DG, 3-deoxyglucosone; CML, N ε- (carboxymethyl)lysine; SD, standard deviation.

_ 63 _

0.054
0.485
0.154

Anti-Glycation Effect of Pomegranate Extract: an Open Clinical Study

HbA1c (%)

Pentosidine (pmol/mL)

6.2

140

6.0

120
＊

100

5.8
＊＊

5.6

80

＊＊

60

5.4

40

5.2

20
0

5.0
0W

8W

0W

12 W

12 W

Fig.4. Serum pentosidine

Fig.1. Serum HbA1c**p < 0.01 vs. 0W, n = 10, by Dunnett’s test.
Bar indicates standard deviation.

*­p < 0.05 vs. 0W, n = 10, by Dunnett’s test.
Bar indicates standard deviation.

CML (mg/mL)

Glycoalbumin (%)
16.0

7.0

15.5

6.0

＊＊

15.0

8W

＊

5.0

14.5

4.0

14.0

3.0

13.5

2.0

13.0

1.0

12.5

0.0

12.0
0W

8W

0W

12 W

Fig. 2. Serum glycoalbumin

Fig. 5. Serum CML**p < 0.01 vs. 0W, n = 10, by Dunnett’s test.
Bar indicates standard deviation.

*p < 0.05 vs. 0W, n = 10, by Dunnett’s test.
CML; N ε-(carboxymethyl) lysine.
Bar indicates standard deviation.

3DG (ng/mL)
35.0
30.0
25.0

＊＊

20.0
15.0
10.0
5.0
0.0
0W

8W

8W

12 W

Fig. 3. Serum 3DG**p < 0.01 vs. 0W, n = 10, by Dunnett’s test. 3DG; 3-deoxyglucosone.
Bar indicates standard deviation.

_ 64 _12 W

Glycative Stress Research

Table 6. Skin fluorescent AGEs and elasticity index.
Parameter

0W

8W

12 W

mean

±

SD

mean

±

SD

p value

mean

±

SD

p value

Skin fluorescent AGEs

2.37

±

0.39

2.33

±

0.31

0.811

2.35

±

0.20

0.965

Skin elasticity test (R2)

0.817

±

0.038

0.830

±

0.033

0.291

0.816

±

0.031

0.998

Skin elasticity test (R5)

0.609

±

0.073

0.643

±

0.055

0.151

0.636

±

0.050

0.278

Skin elasticity test (R6)

0.367

±

0.040

0.384

±

0.038

0.498

0.374

±

0.030

0.867

Skin elasticity test (R7)

0.446

±

0.055

0.465

±

0.044

0.251

0.463

±

0.034

0.334

p Value vs. 0W, n = 10, by Dunnett’s test. AGEs, advanced glycation end products; SD, standard deviation.

Discussion
Effects of pomegranate extract (PE)The active ingredient of test products is PE. The extractsof pomegranate seed, rind, flower are reported, in in vitro
studies, experimental animals and culture cells, to show various
activities including anti-oxidant capacity 14, 15), anti-inflammation
16-19), anti-bacteria 20-23), anti-tumor 24- 27), and anti-diabetes 28 - 30).
PE shows anti-bacterial actions against Listeria monocytogenes
21), Pseudomonas stutzeri 22), and Staphylococcus aureus 23).
Anti-tumor effect was shown against cell lines derived frommammalian gland cancer 24), ovarian cancer 24), endometrium
cancer 24), osteosarcoma 25), colon cancer 26) and prostate cancer
27). Furthermore, in rats PE is reported, to show a preventive
effect against carvacrol on methotrexate-induced bone marrow
toxicity 31), renal ischemia-reperfusion injury 32), hepatotoxicity
induced by diethylnitrosamine and phenobarbital 33), andbleomycin-induced pulmonary fibrosis 34).
PE seems favorable towards sugar metabolism showing
anti-diabetic actions 28 - 30) . Recent research has focused on
the mechanism of PE actions and experiments using diabetic
rats have demonstrated the stimulation of insulin secretion35)
and inhibition of α-amylase and α-glucosidase 36). PPARγ
activation by PE 37) may be involved in these actions. As aresult, PE is expected to be a possible treatment for fatty liver38)
and hypertension care 39), wound healing enhancement 40, 41)
and cognitive function improvement 42).
Recent studies on anti-glycation activity by PE have shownthat PE inhibits albumin glycation 43) and AGEs generation
3, 44, 45). In these findings on anti-diabetic actions, the basi of PE
actions may be its anti-glycation effect.

Data interpretation

In the present study, after the 12-week PE administration,
glycative stress markers, FPG and IRI did not change. HbA1c,
glycoalbumin, 3DG and pentosidine were significantly reduced
at 8 weeks, and HbA1c stayed significantly low at 12 weeks.
PE, as in the previously reported experiments, may fulfill its
anti-glycation effect, thus reducing AGEs generation in the
body. The reason why CML tended to increase still remains
unclear. In order to obtain new findings, we have a study planin the next trial to check skin corneal CML by the tape stripping
method 46).
Since the purpose is focused on confirming safety andeffect as a pilot open study, the subjects were limited only tohealthy persons, those who include both persons with highglycation stress and persons with normal glycation stress. In
the latter, markers such as skin fluorescent AGEs may be low
or normal, and there would be no room for reducing thesemarkers by PE intake. It is necessary to modify the design in a
subsequent study, for an example, to include subjects with highskin fluorescent AGEs as assessed by screening.
In a previous clinical study of type 2 diabetic patientsand healthy subjects, serum malondialdehyde (MDA) andhydroxynonenal (HN) were reduced only in the diabetic
patients; they were not changed in the healthy subjects 47).
The reason may be that MDA and HN were almost normal in
the healthy persons and there was no room for improvement.
Similarly, in the present study the subjects were healthy
persons and skin fluorescent AGEs were not reduced for thesame reason.
There were no adverse effects claimed in this study,
indicating that PE can be considered a safe product. The
evaluation of safety will be described in the next report.

Conclusions

In this open study without control subjects to elucidate
the anti-glycation activity of PE, the subjects were 10 postmenopausal females who received oral administration of PE
100 mg/day for 12 weeks, and as a result, some glycative stressmarkers were reduced. This finding indicates an equivocal
effect of PE on glycative stress improvement. Further studies
are necessary to elucidate the anti-glycation effect of PE, suchas a double-blind randomized controlled trial with subjects
with high glycation stress with skin fluorescent AGEs selectedby screening.

Conflict of interest statement

The authors are indeted to the Fund “Research anddevelopment support program for regional revitalization inagriculture, forestry, fisheries and in the food industry sector’’of the New Business and Intellectual Property Division, Food
Industry Affairs Bureau, from the Ministry of Agriculture,
Forestry and Fisheries of Japan, 2013.
Mr. Matsuura, Mr. Nishida, and Mr. Nagatomo areemployees of Morishta Jintan Co., Ltd., and were not involvedin the data analysis.

_ 65 _

Anti-Glycation Effect of Pomegranate Extract: an Open Clinical Study

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