Glycative Stress Research
Online edition : ISSN 2188-3610
Print edition : ISSN 2188-3602
Received : October 18, 2021
Accepted : November 17, 2021
Published online : December 31, 2021
doi:10.24659/gsr.8. 4_162

Original article

Anti-glycative effect and total phenolic content of rice water ofdifferent Japonica and Indica varieties
Ursula Pasandee Pabasara Wickramasinghe, Masayuki Yagi, Yoshikazu Yonei
Anti-Aging Medical Research Center and Glycative Stress Research Center, Faculty of Life and Medical Sciences,
Doshisha University, Kyotanabe, Kyoto, Japan

Abstract

Glycation is a non-enzymatic reaction between reducing sugars and amino group proteins which leads to the formation ofadvanced glycation end products (AGEs). The buildup of AGEs in the body is a key factor in the onset of aging and lifestylerelated diseases. In this study, the inhibitory effect on the formation of AGEs by rice water was investigated. Rice water is acommon ingredient used traditionally as a beautifying agent but lacks proper scientific research. 14 Japonica and Indica rice
varieties were used to prepare rice water samples using three different methods, namely type 1, type 2, and type 3 (n = 42).
The human serum albumin (HSA) glycation model was used to evaluate the inhibitory effect on the formation of fluorescent
AGEs by rice water. The total phenolic content (TPC) in rice water was determined according to the Folin-Ciocalteau
procedure. All 42 rice water samples showed an inhibitory effect on the formation of fluorescent AGEs, and positive
correlations were observed between the inhibitory effect and the TPC at p < 0.05; type 1 rice water (r = 0.906 ), type 2 ricewater (r = 0.918), and type 3 rice water (r = 0.765). It was also observed that rice water prepared from pigmented rice varieties
showed the highest inhibitory values, for example, type 1 sample number 1 (66.4 ± 0.4 %), type 2 sample number 1 (66.6± 0.7 %), and type 3 sample number 12 (69.6 ± 0.8 %). Consequently, the results from this study verifies the anti-glycative
effect of rice water and suggests the TPC plays a role on the anti-glycative effect of rice water.

KEY WORDS: rice water, glycative stress, advanced glycation end products (AGEs), total phenolic content

Introduction
Rice is one of the most widely consumed staple foods
for a large part of the world’s population, mainly in Asia andit is also an important beautifying agent. Traditionally, womenfrom Japan, China, and some Southeast Asian countries
have used rice water to beautify their face, skin, and hair.
Oryza sativa is the plant species most commonly referred
to as rice. It contains two major subspecies; the sticky,
short-grained Japonica variety, and the non-sticky, longgrained Indica rice variety 1). Rice also occurs in a varietyof colors, including white, brown, black or purple, and red.
However, the benefits of rice water are not supported byenough scientific research although cosmetic manufacturers
greatly assert the benefits of rice water on skin.
Recently, the search for new, natural, and mostimportantly organic bioactive compounds to prevent skinaging has greatly increased. Rice water is natural, economicaland simple, and could be easily included in skincare products.
Different types of rice are readily available as it is a large partof the human diet, and it can easily be obtained from the riceindustry as well. Rice bran oil is recognized for containing
antioxidant-rich components such as ferulic acid, γ -oryzanol,and phytic acid 2). These components have been establishedand used in the cosmetic industry, and in the managementof skin diseases 3). Rice bran bioactive compounds have beenfound to be efficient in the treatment of alopecia 4) and also
have an anti-aging potential 5). Starch, which is the major
component in rice grains, is a biodegradable polymer withsafe application in the pharmaceutical industry. Starch isrecommended to be added to bath water as it is said to help
with the treatment of atopic dermatitis or other skin diseases
associated with pruritus 6). A study done in Portugal presented
in vitro biological antioxidant activity and elastase inhibitory
effects by rice water. Their clinical study done using a topicalgel formulation containing 96 % rice water was shown
to be biocompatible with the human skin and presented
suitable cosmetic properties 7). It has also been shown that thebioactive compounds present in rice have huge potential for

Corresponding to: Professor Yoshikazu Yonei, MD, PhD
Anti-Aging Medical Research Center and Glycative Stress Research Center,
Faculty of Life and Medical Sciences, Doshisha University
1-3, Tatara Miyakodani, Kyotanabe, Kyoto, 610 - 0394 Japan
TEL & FAX: +81-774 - 65- 6394 e-mail: yyonei@mail.doshisha.ac.jp
Co-authors: Wickramasinghe UPP, cygb2502@mail4.doshisha.ac.jp;
Yagi M, myagi@mail.doshisha.ac.jp

Glycative Stress Research 2021; 8 (4 ): 162-170(c) Society for Glycative Stress Research_ 162 _Glycative Stress Researchmany health benefits and has anti-tumor, anti-atherosclerosis,
anti-diabetic, anti-allergic agents, alleviation of gallstones,anti-cancer activity, anti-inflammatory, and other effects 8).
Rice water, which is used as folklore medicine in
Sri Lanka, is classified into three types according to thedifference in manufacturing method, and there are various
varieties such as those from Southeast Asia and Japan.
The main purpose of this study is to verify the presenceor absence of anti-glycation effect as a new function ofrice water. Glycation is a non-enzymatic chemical reaction
between amino acids or proteins and reducing sugars,
which was discovered by Louis-Camille Maillard, a French
scientist. This reaction is also called the Maillard reaction 9).
These glycated proteins lead to the formation of advanced
glycation end products (AGEs) that are accumulated invarious tissues and organs. AGEs induce inflammation,
pigmentation, and deterioration of physiological functionthat lead to aging 10). The phenomenon of the accumulationof these cytotoxic and irreversibly-formed sugar-derived
AGEs that contribute to aging, age-related diseases, andother metabolic diseases such as diabetes, cancer, kidney,ocular, and cardiovascular diseases is known as glycative
stress 11). In addition, we will compare the difference in effectdepending on the variety and manufacturing method and thetotal phenol content (TPC), as it has been reported that TPC
was responsible for the anti-glycation potential of rice 12). We
would like to know the varieties and manufacturing methods
that efficiently exert anti-glycation effects.

Table 1. Rice samples used in this study.

Materials and methods
Samples and reagentsThe 14 rice samples used in this study were purchased
randomly at readily available stores across Japan and
Sri Lanka ( Table 1). Human serum albumin (HSA) was
purchased from Sigma-Aldrich (Meguro-ku, Tokyo). Allother chemicals were analytical grade and purchased from
Fujifilm Wako Pure Chemical Corporation (Osaka, Japan) or
Nacalai Tesque, Inc. (Kyoto, Japan).

Rice water preparation by three different methods
Based on the traditional usage in Sri Lanka, thefollowing three types of rice water samples were prepared.

Type 1Three grams of rice was boiled in 36 mL of distilled waterat 10 0 ºC for 30 minutes. Samples were centrifuged at 2,500rpm for ten minutes at room temperature, and filtered.

Type 2Five grams of rice was oven-dried at 160 ºC for 30 minutes.
Three grams of oven-dried rice was boiled in 36 mL of distilledwater at 100 ºC for 30 minutes. Samples were centrifuged at2,500 rpm for ten minutes at room temperature, and filtered.

SamplenumberSample nameSubspecies

Color

Country oforigin andpurchase

Additional details regarding source of material

1

Asamurasaki

Japonica

Black

Japan

Purchased from Tomizawa Shoten (TOMIZ),
Product No. 00347802

2Black Kodaimai

Japonica

Black

Japan

Purchased from Asuka Kanko

3

Dik Vee

IndicaRed

Sri Lanka

Purchased from Siriketha Products, Ethkandura

4

Hitomebore

Japonica

Brown

Japan

Purchased from Rice Friend, Takashimaya Osaka store

5

Koshihikari

Japonica

Brown

Japan

Purchased from Rice Friend, Takashimaya Osaka store

6

Kuruluthuda

IndicaRed

Sri Lanka

Purchased from Siriketha Products, Ethkandura

7

Ma VeeIndicaWhite

Sri Lanka

Purchased from a local farmer in the Gampaha district

8

Madathavalu

IndicaWhite

Sri Lanka

Purchased from a local farmer in the Gampaha district

9

Martin Samba

IndicaWhite

Sri Lanka

Purchased from a local farmer in the Gampaha district

10

Mixed Kodaimai

Japonica

Mixed(black,Japan
green, red)

Purchased from Asuka Kanko

11

Pachchaperumal

IndicaRed

Sri Lanka

Purchased from a local farmer in the Gampaha district

12

Red Kodaimai

Japonica

Red

Japan

Purchased from Asuka Kanko

13

Suduru Hel

IndicaWhite

Sri Lanka

Purchased from a local farmer in the Gampaha district

14

Yuyakemochi

Japonica

Red

Japan

Purchased from Tomizawa Shoten (TOMIZ),
Product No. 00347901_ 163 _

Anti-glycative Effect and Phenolic Content of Rice Water

Type 3

Statistical analysis

Three grams of rice was soaked in 9 mL of distilled water atroom temperature for six hours. Samples were centrifuged at2,500 rpm for ten minutes at room temperature, and filtered.

The measured values are shown as mean ± standard
deviation. Comparisons between groups were performed inmeasurements using the Tukey’s test. Correlation analysis
between the measured values was performed using thePearson correlation coefficient. Differences were consideredsignificant at P values less than 0.05.

A solid concentration (mg/mL) was obtained after 3 mLof rice water was placed on an aluminum tray and the weights
were measured before and after dehydration at 120 ºC for
120 minutes. Samples were prepared for the experiments byadjusting the concentration with distilled water to 1 mg/mLof solid concentration.

Preparation of glycated proteins

The HSA glycation model 13) was used to evaluate theeffect of type 1, type 2, and type 3 rice water on glycation.
25 μL of the samples were added to 125 μL of 0.1 mol/L
phosphate buffer solution (pH 7.4), 25 μL of distilled water,
50 μL of 40 mg/mL HSA, and 25 μL of 2.0 mol/L glucose(solution A). Distilled water was added instead of the glucoseof solution A as a blank (solution B). At the same time, distilledwater was added instead of the samples of solution A as a
blank (solution C). A mixed solution containing purified waterinstead of the glucose solution of solution C was also prepared(solution D). 1 mg/mL aminoguanidine (AG) 14), a known
AGE formation inhibitor, was used as a positive control. The
reaction mixtures were incubated at 60 ºC for 4 0 hours.

Measurement of fluorescent AGEs
The volume of fluorescent AGEs after incubation wasmeasured as reported previously 13). Concisely, 200 μL of
the reaction mixture was used to measure fluorescence bya Varioscan® Flash microplate reader (Thermo Scientific,
Waltham, MA) at an excitation wavelength of 370 nm and anemission wavelength of 440 nm. The fluorescence intensity
was calculated as a relative value when the fluorescenceintensity of 5 μg/mL quinine sulfate was 1,000. The production
inhibition rate (%) of fluorescent AGEs was calculated by
the following formula.
Inhibition of fluorescent AGE formation (%) =[ 1 − (A−B) / (C − D)] × 100

Measurement of total phenolic content (TPC)
TPC was determined according to the Folin–Ciocalteau
procedure 15) with some modifications that do not change thefinal result. Concisely, 50 μL of the reaction mixture (5 μL
sample, 20 μL distilled water and 25 μL ethanol) was mixed
with 250 μL of 0.4 M sodium carbonate followed by 25 μL
of 50 % Folin-Ciocalteau reagent. Distilled water was usedinstead of Folin-Ciocalteau reagent as a blank. The mixtures
were well mixed and incubated at 30 ºC for 30 minutes. The
mixtures were then allowed to stand at room temperature foranother 30 minutes. Absorbance was measured at 660 nm bya Varioscan® Flash microplate reader (Thermo Scientific,
Waltham, MA). TPC was expressed as catechin equivalent(µM catechin eq) determined by a calibration curve, which
was graphed following the same procedure using catechin as
the standard phenolic compound 15).

Results

Inhibitory effect on formation of AGEs
The inhibitory effect on the formation of AGEs by type 1,
type 2 and type 3 rice water prepared using 14 rice samples(n = 42), and AG are shown in Fig 1. All 42 rice water
samples inhibited the formation of fluorescent AGEs. Sample
number 1 showed the highest inhibition on the formation offluorescent AGEs among type 1 rice water samples (66.4 ±0.4 %, Fig. 1-a ). Sample number 1 also showed the highest
inhibition on the formation of fluorescent AGEs among
type 2 rice water samples (66.6 ± 0.7 %, Fig. 1- b ). Sample
number 12 showed the highest inhibition on the formationof fluorescent AGEs among type 3 rice water samples,and among all 42 rice water samples (69.6 ± 0.8 %, Fig.
1-c). There was a significant difference ( p < 0.05) between
the different types of rice water samples except in sample
number 1, as shown in Fig 2. Comparing within the groups,
sample numbers 2 and 3 showed the highest inhibition on theformation of fluorescent AGEs in type 1 rice water, sample
number 1 showed the highest inhibition in type 2 rice water,and sample numbers 5, 6, 7, 8, 9, 10, 11, 12, 13, and 14
showed the highest inhibition in type 3 rice water. Amongthe 14 rice samples studied, all rice water samples (n = 42)
showed lower inhibition that that of AG.

Total phenolic content (TPC) in rice water
The TPC in type 1, type 2 and type 3 rice water preparedusing 14 rice samples (n = 42) are shown in Fig. 3. All 42 ricewater samples contained phenolic compounds. Sample number
1 showed the highest TPC among type 1 rice water samples(94.7 ± 4.9 µM catechin eq), type 2 rice water samples (124.8± 7. 5 µM catechin eq), and type 3 rice water samples (176.2± 3.4 µM catechin eq). Comparing within the groups, sample
numbers 3 and 11 had the highest TPC in type 1 rice water,and sample numbers 1, 2, 4, 5, 6, 7, 8, 9, 10, 12, 13, and 14
had the highest TPC in type 3 rice water.

Correlation analysis

Fig. 4 shows the correlation results between the T PC and
the inhibitory effect on the formation of fluorescent AGEs.
Fig. 4-a shows that there is a strong positive correlation
between TPC and inhibition of fluorescent AGEs in type 1
rice water (r = 0.906). Similarly, a strong positive correlation
was observed between TPC and inhibition of fluorescent
AGEs in type 2 rice water (r = 0.918, Fig. 4-b). A moderately
strong positive correlation was seen between TPC andinhibition of fluorescent AGEs in type 3 rice water (r = 0.765,
Fig. 4-c).

_ 16 4 _a)Inhibition of fluorescent AGEs (%)

Glycative Stress Research

80
70
60
50

Black rice40

Red rice
Mixed rice30

Brown rice

20

White rice

10
0

1

2

3

8

6

12

14

10

11

4

13

5

7

9

AG

b)

Inhibition of fluorescent AGEs (%)

Sample number
80
70
60
50

Black rice40

Red rice
Mixed rice30

Brown rice

20

White rice

10
0

1

2

12

14

10

13

8

9

6

3

5

7

4

11

AG

c)

Inhibition of fluorescent AGEs (%)

Sample number
80
70
60
50

Black rice40

Red rice
Mixed rice30

Brown rice

20

White rice

10
0

12

1

8

11

10

2

13

6

14

5

3

9

7

4

AG

Sample number

Fig. 1. Inhibition of fluorescent AGE formation by (a) type 1 rice water and AG, (b) type 2 rice water and AG,(c) type 3 rice water and AG.
Rice water samples were introduced into glycation models containing 8 mg/mL HSA and 0.2 mol/L glucose. After 40 hours
incubation at 60 °C, fluorescent AGEs were measured at 370/440 nm. The final concentration of samples was 1 mg/mL and thatof AG was 0.1 mg/mL. Results are expressed as mean ± standard deviation, n = 3. Sample number; 1, Asamurasaki, 2, Black
Kodaimai, 3, Dik Vee, 4, Hitomebore, 5, Koshihikari, 6, Kuruluthuda, 7, Ma Vee, 8, Madathavalu, 9, Martin Samba, 10, Mixed
Kodaimai, 11, Pachchaperumal, 12, Red Kodaimai, 13, Suduru Hel, 14, Yuyakemochi. AGEs, advanced glycation end products;
AG, aminoguanidine; HSA, human serum albumin.

_ 165 _

Anti-glycative Effect and Phenolic Content of Rice Water

80

Inhibition of fluorescent AGEs (%)

70
60
50

Type 140Type 2Type 3

30
20
10
0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Sample number

Fig. 2. Comparison of the inhibition of fluorescent AGEs formation by the 3 types of rice water.

The final concentration of samples was 1 mg/mL. Results are expressed as mean ± standard deviation, n = 3, *p < 0.05,**p < 0.01 by Tukey’s test. Sample number; 1, Asamurasaki, 2, Black Kodaimai, 3, Dik Vee, 4, Hitomebore, 5,
Koshihikari, 6, Kuruluthuda, 7, Ma Vee, 8, Madathavalu, 9, Martin Samba, 10, Mixed Kodaimai, 11, Pachchaperumal,
12, Red Kodaimai, 13, Suduru Hel, 14, Yuyakemochi. AGEs, advanced glycation end products.

200

Total phenolic content (µM catechin eq)

180
160
140
120
100

Type 180

Type 3

Type 2

60
40
20
0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Sample number

Fig. 3. Comparison of the TPC in the 3 types of rice water.

The final concentration of samples was 1 mg/mL. Results are expressed as mean ± standard deviation, n = 3. *p < 0.05,**p < 0.01 by Tukey’s test. Sample number; 1, Asamurasaki, 2, Black Kodaimai, 3, Dik Vee, 4, Hitomebore, 5,
Koshihikari, 6, Kuruluthuda, 7, Ma Vee, 8, Madathavalu, 9, Martin Samba, 10, Mixed Kodaimai, 11, Pachchaperumal,
12, Red Kodaimai, 13, Suduru Hel, 14, Yuyakemochi. TPC, total phenolic content.

_ 16 6 _Glycative Stress Research

80

Inhibition of fluorescent AGEs (%)a)

70

r = 0.906
p < 0.01

60
50
40
30
20
10
0

0

20

40

60

80

100

Total phenolic content (µM catechin eq)
80

Inhibition of fluorescent AGEs (%)b)

70
r = 0.918
p < 0.01

60
50
40
30
20
10
0

0

20

40

60

80

100

120

140

Total phenolic content (µM catechin eq)
80

Inhibition of fluorescent AGEs (%)c)

r = 0.765
p < 0.01

70
60
50
40
30
20
10
0

0

50

100

150

200

Total phenolic content (µM catechin eq)

Fig. 4. Correlation of inhibition of fluorescent AGEs formation to TPC of (a) type 1 rice water,(b) type 2 rice water, (c) type 3 rice water.

p < 0.01, r = Pearson correlation coefficient. TPC, total phenolic content; AGEs, advanced glycation end products.

_ 167 _

Anti-glycative Effect and Phenolic Content of Rice Water

Discussion

phenolic compounds identified in rice, such as tocopherols,
tocotrienols and γ -oryzanol 29).

In this study, the anti-glycative effect and the TPC ofthree different rice water preparations using 14 rice samples
was studied. The 14 rice samples included two black rice
varieties, five red rice varieties, two brown rice varieties, four
white rice varieties, and one mixed rice variety. Different
pigmented rice varieties were chosen as previous studies haveshown various health benefits of pigmented rice compared towhite rice. Although white rice makes a major contribution
to the calorific intake of most Asian populations and otherpopulations around the world, its nutritional quality is low
compared to that of pigmented rice varieties 16). Pigmented
rice have been reported as a potent source of phytonutrients
including antioxidant compounds, and that they have marked
health benefits in preventing diabetic complications aswell 17, 18). Pigmented rice contains a range of bioactive
compounds including phenolic acids and flavonoids 19).
Several epidemiological studies have suggested that a highdietary consumption of polyphenols is associated with adecreased risk of various diseases including cardiovasculardisease 20, 21) and neurodegenerative diseases 22). It has beenshown that the concentration of phenolic compounds are
positively associated with the antioxidant activity and could
aid in the prevention of cancer 23 -25).

Relationship with total phenolic content (TPC)

Research backgroundAnti-glycation effect as a new functionality
In this study, rice water, which is a natural, economicaland simple product was used as the primary test sample.
Rice water is prepared by different methods with different
purposes globally, however, it always involves rice grains
in contact with water. In order to examine which rice water
preparing method would result in rice water with a higher
anti-glycative effect, three traditional methods from Sri
Lanka were replicated in the lab and used in this study to
prepare the rice water. Type 1 was made by boiling, type 2
by oven-drying and boiling, and type 3 by soaking in water.
A study conducted in Japan has shown hair care benefits
by rinsing with water obtained from the washing of rice 26),
which is quite similar to the type 3 rice water of this study.
The anti-glycative effect of rice water was verified bymeasuring the inhibitory effect on the formation of fluorescent
AGEs using the HSA glycation model 13). Rice water was
incubated with HSA and glucose at 60 ºC for 40 hours toevaluate its anti-glycative effect. This glycation reaction is a
non-enzymatic one controlled by reaction temperature andtime. Previous studies show that the formation of fluorescent
AGEs at 60 ºC for 40 hours was equivalent to that obtained
from a reaction time of about 60 days at 37 ºC 27). The positive
control used when measuring the inhibitory effects of AGEs,
aminoguanidine (AG), is an inhibitory agent of the glycation
reaction. AG is an AGE formation inhibitor developed withthe aim of curing diabetic complications 28). AG blocks the
carbonyl group in molecules of the intermediate productsof glycative reactions. However, AG is not approved as a
medical product in the domestic market, because a side effect
was recognized in Japan. All 42 rice water samples showed
an inhibitory effect on the formation of fluorescent AGEs.
This could be due to the transference to the water of several

Rice water application has been a popular folk remedy
for skin lightening, increasing elasticity of skin, and soothing
sun damage. This study verifies the anti-glycative effectsof rice water from a viewpoint of skin aging prevention.
However, there is a significant difference of inhibition values
between the different types of rice water preparations, andbetween the different varieties of pigmented rice. Type 3 ricewater showed higher inhibition values in average compared
to type 1 and type 2 rice water. Black and red rice varieties
showed higher inhibition values in average compared tobrown, mixed, and white rice varieties. This suggests thatthe pigment, which is located in the aleurone layer of ricecontains higher amount of phenolic compounds such as
anthocyanins 17). A previous study has shown that the TPC
was positively correlated to the anti-AGE formation capacityof different pigmented Thai rice varieties 12). These results
also agree with previous studies that have reported pigmented
rice having higher phenolic compounds 17, 30).
Also in this study, strong positive correlation results
can be seen between the TPC and inhibitory effect on theformation of fluorescent AGEs by all three types of ricewater. Similar results have been observed in another study
that shows a positive correlation of the TPC, antioxidant
activities, and anti-AGEs formation capacity of rice bean
in China 31). Additionally, similar relationships have been
observed in garcinol from Garcinia indica fruit rind 32),
and in Camellia sinensis 33). These results indicate that the
inhibition of AGEs formation depend on the TPC. Type 3
rice water showing higher inhibition of fluorescent AGEs
could be due to the fact that boiling in water led to the lossof soluble phenolic compounds in type 1 and type 2 ricewater. In most rice samples, the type 2 rice water preparation
method led to lower inhibition rates. This could be due to theextreme heat applied to the rice over a longer period of time(160 ºC for 30 minutes and 100 ºC for another 30 minutes)
when compared to the other two rice water preparing
methods. The extreme heat over a longer period of timemight have led to a higher loss or degradation of phenolic
compounds, thus decreasing the inhibition potential of type2 rice water. A previous study has shown that cooking ofrice led to a significant decrease in inhibitory capacity ofangiotensin I-converting enzyme (ACE) accompanied by arelative reduction in the soluble phenolic content 34). These
results also agree with another study that shows the TPC was
lower in rice water prepared by the boiling process 7). It has
also been shown that heat significantly affected the amountof phenolic compounds in other foods 35-37). This could also
be the reason for type 3 rice water to show a moderately
strong positive correlation with its TPC. It could also bethat another factor in addition to the TPC is playing a rolein the inhibition of AGEs in type 3 rice water. However, thisremains unknown therefore future research efforts should
be focused on identifying other factors except TPC thatare responsible for the anti-glycation effect of type 3 ricewater.

_ 16 8 _Glycative Stress Research

Conclusion

Acknowledgements

This study is the first report on a correlation between
the inhibition of AGE formation and the TPC in rice waterof various pigmented and non-pigmented Japonica andIndica varieties. This study shows that rice water has an antiglycation effect (AGE production inhibitory effect) as a novel
function. This study also shows that rice water produced
using pigmented rice varieties have a higher inhibitory effectagainst fluorescent AGE formation, and that there is a strong
positive correlation between the inhibitory effect and the
TPC of rice water. Among the traditional manufacturingmethods, type 3 rice water, produced by soaking rice in water,
has the strongest action, and among the varieties, sample
number 1 (Asamurasaki, black Japonica variety) and sample
number 12 (Red Kodaimai, red Japonica variety) have strong
actions. A correlation was found between the strength of theanti-glycation effect and the TPC content, suggesting TPC( i.e., phenolic compounds in rice such as ferulic acid 38) ) as acomponent involved. From the above, it was suggested thatrice water may contribute to beauty and health maintenancethrough its anti-glycation function when topically used onskin.

A part of this study was presented at the 18th meetingof the Society for Glycative Stress Research in October 2018,
Tokyo, Japan. This study was presented at the 23rd Glycation
Stress Study Group Lecture in August 2021, Kumamoto, Japan.
This study was also presented at IMARS-14 in September
2021, Doha, Qatar. This study was carried out at the Graduate
School of Life and Medical Sciences, Doshisha University.
We thank Mr. M.C. Wickramasinghe and Mrs. T. M. L. K.
Thilakaratna for providing the Indica rice samples. The
publication of this study was supported by the Isyoku-Dogen
Research Foundation (IDF#22002).

References
1) Garris AJ, Tai TH, Coburn J, et al. Genetic structure anddiversity in Oryza sativa L. Genetics. 2005; 169: 16311638.
2) Pal YP, Pratap AP. Rice bran oil: A versatile source foredible and industrial applications. J Oleo Sci. 2017; 66:
551-556.
3) Lerma-García MJ, Herrero-Martínez JM, Simó-Alfonso EF,
et al. Composition, industrial processing and applicationsof rice bran γ -oryzanol. Food Chemistry. 2009; 115: 389404.
4) Choi J-S, Park JB, Moon W-S, et al. Safety and efficacyof rice bran supercritical CO 2 extract for hair growth inandrogenic alopecia: A 16-week double-blind randomized
controlled trial. Biol Pharm Bull. 2015; 38: 1856-1863.
5) Kanlayavattanakul M, Lourith N, Chaikul P. Jasmine ricepanicle: A safe and efficient natural ingredient for skinaging treatments. J Ethnopharmacol. 2016; 193: 607-616.
6) De Paepe K, Hachem JP, Vanpee E, et al. Effect of ricestarch as a bath additive on the barrier function of healthy
but SLS-damaged skin and skin of atopic patients. Acta
Derm Venereol. 2002; 82: 184-186.
7) Marto J, Neves Â, Gonçalves L, et al. Rice water: A
traditional Ingredient with anti-aging efficacy. Cosmetics.
2018; 5(2): 26.
8) Samyor D, Das AB, Deka SC. Pigmented rice a potential
source of bioactive compounds: A review. International
Journal of Food Science & Technology. 2017; 52: 10731081.

Conflict of interest declaration
This study was supported by the Japanese Council
for Science, Technology and Innovation, SIP (Project ID:
14533567), “ Technologies for creating next-generation
agriculture, forestry and fisheries” (funding agency: Biooriented Technology Research Advancement Institution,
NARO), and the Research Foundation of Crude Drug gained
from the same source of Medicine & Food (funding number:IDF#21002). Funding acquisition by Y.Y. The funders had
no role in study design, data collection and analysis, decision
to publish, or preparation of the manuscript.

9) Zhang Q, Ames JM, Smith RD, et al. A perspective on

the Maillard reaction and the analysis of protein glycation
by mass spectrometry: Probing the pathogenesis ofchronic disease. J Proteome Res. 2009; 8: 754-769.
10) Nagai R, Mori T, Yamamoto Y, Kaji Y, et al. Significanceof advanced glycation end products in aging-relateddisease. Anti-Aging Med. 2010; 7: 112-119.
11) Rowan S, Bejarano E, Taylor A. Mechanistic targeting ofadvanced glycation end-products in age-related diseases.
Biochim Biophys Acta Mol Basis Dis. 2018; 1864: 36313643.
12) Daiponmak W, Senakun C, Siriamornpun S. Antiglycation
capacity and antioxidant activities of different pigmented
Thai rice. International Journal of Food Science &Technology. 2014; 49: 1805-1810.
13) Ishioka Y, Yagi M, Ogura M, et al. Antiglycation effect ofvarious vegetables: Inhibition of advanced glycation end
product formation in glucose and human serum albumin
reaction system. Glycative Stress Res. 2015; 2: 22-34.
14) Hammes HP, Martin S, Federlin K, et al. Aminoguanidine
treatment inhibits the development of experimental
diabetic retinopathy. Proc Natl Acad Sci U S A. 1991; 88:11555-11558.
15) Stevanato R, Fabris S, Momo F. New enzymatic method
for the determination of total phenolic content in tea andwine. J Agric Food Chem. 2004; 52: 6287-6293.
16) Mbanjo EGN, Kretzschmar T, Jones H, et al. The genetic
basis and nutritional benefits of pigmented rice grain.
Front Genet. 2020; 11: 229.

_ 169 _

Anti-glycative Effect and Phenolic Content of Rice Water

17) Yawadio R, Tanimori S, Morita N. Identification ofphenolic compounds isolated from pigmented rices andtheir aldose reductase inhibitory activities. Food Chemistry.
2007; 101: 1616-1625.
18) Morimitsu Y, Kubota K, Tashiro T, et al. Inhibitory effectof anthocyanins and colored rice on diabetic cataract
formation in the rat lenses. International Congress Series.
2002; 1245: 503-508.
19) Wongsa P. Phenolic compounds and potential healthbenefits of pigmented rice. Recent Advances in Rice
Research. 2020. DOI: 10.5772/intechopen.93876.
20) Lo LMP, Kang MY, Yi SJ, et al. Dietary supplementationof germinated pigmented rice (Oryza sativa L.) lowers
dyslipidemia risk in ovariectomized Sprague–Dawley
rats. Food Nutr Res. 2016; 60: 30092.
21) Ling WH, Cheng QX, Ma J, et al. Red and black ricedecrease atherosclerotic plaque formation and increase
antioxidant status in rabbits. J Nutr. 2001; 131: 1421-1426.
22) Vargas CG, Da Silva Junior JD, Rabelo TK, et al. Bioactive
compounds and protective effect of red and black ricebrans extracts in human neuron-like cells (SH-SY5Y).
Food Res Int. 2018; 113: 57-64.
23) Hu C, Zawistowski J, Ling W, et al. Black rice (Oryza
sativa L. indica) pigmented fraction suppresses bothreactive oxygen species and nitric oxide in chemical andbiological model systems. J Agric Food Chem. 2003; 51:
5271-5277.
24) Hyun JW, Chung HS. Cyanidin and malvidin from Oryza
sativacv. Heugjinjubyeo mediate mytotoxicity against
human monocytic leukemia cells by arrest of G2/M
phase and induction of apoptosis. J Agric Food Chem.
2004; 52: 2213-2217.
25) Chen P-N, Kuo W-H, Chiang C -L, et al. Black riceanthocyanins inhibit cancer cells invasion via repressionsof MMPs and u-PA expression. Chem Biol Interact.
2006; 163: 218-229.
26) Inamasu S, Ikuyama R, Fujisaki Y, et al. The effect of rinse
water obtained from the washing of rice (YU-SU-RU)
as a hair treatment. International Journal of Cosmetic
Science. 2010; 44: 29-33.
27) Yagi M, Yonei Y. Glycative stress and anti-aging: 4.
The evaluation of glycative Stress: Evaluation for antiglycative effect. Glycative Stress Res. 2017; 4: 87-92.
28) Bolton WK, Cattran DC, Williams ME, et al. Randomized
trial of an inhibitor of formation of advanced glycation
end products in diabetic nephropathy. Am J Nephrol. 2004;
24: 32- 40.
29) Walter M, Marchesan E. Phenolic compounds andantioxidant activity of rice. Brazilian Archives of Biology
and Technology. 2011; 54: 371-377.
30) Itani T, Tatemoto H, Okamoto M, et al. A comparative
study on antioxidative activity and polyphenol content ofcolored Kernel rice. Nippon Shokuhin Kagaku Kogaku
Kaishi. 2002; 49: 540-543.
31) Yao Y, Cheng X- Z, Wang L-X, et al. Major phenolic
compounds, antioxidant capacity and antidiabetic potentialof rice bean (Vigna umbellata L.) in China. Int J Mol Sci.
2012; 13: 2707-2716.
32) Yamaguchi F, Ariga T, Yoshimura Y, et al. Antioxidative
and anti-Glycation Activity of garcinol from Garcinia
indica fruit rind. J Agric Food Chem. 2000; 48: 180-185.
33) Ho S-C, Wu S-P, Lin S-M, et al. Comparison of antiglycation capacities of several herbal infusions with thatof green tea. Food Chemistry. 2010; 122: 768-774.

34) Massaretto IL, Madureira Alves MF, Mussi De MiraNV, et al. Phenolic compounds in raw and cooked rice
(Oryza sativa L.) and their inhibitory effect on the activityof angiotensin I-converting enzyme. Journal of Cereal
Science. 2011; 54: 236-240.
35) Ghafoor K, Ahmed IAM, Doğu S, et al. The effect ofheating temperature on total phenolic content, antioxidant
activity, and phenolic compounds of plum and mahaleb
fruits. International Journal of Food Engineering. 2019;15 (11-12).
36) Xu G, Ye X, Chen J, et al. Effect of heat treatment on thephenolic compounds and antioxidant capacity of citrus
peel extract. J Agric Food Chem. 2007; 55: 330-335.
37) Maghsoudlou Y, Asghari Ghajari M, Tavasoli S. Effects ofheat treatment on the phenolic compounds and antioxidant
capacity of quince fruit and its tisane’s sensory properties.
J Food Sci Technol. 2019; 56: 2365-2372.
38) Tian S, Nakamura K, Kayahara H. Analysis of phenolic
compounds in white rice, brown rice, and germinatedbrown rice. J Agric Food Chem. 2004; 52: 4808-4813.

_ 170 _