Content uploaded by Hataichanoke Niamsup
Author content
All content in this area was uploaded by Hataichanoke Niamsup on Jul 10, 2016
Content may be subject to copyright.
Chiang Mai J. Sci. 2014; 41(1) 105
Chiang Mai J. Sci. 2014; 41(1) : 105-116
http://epg.science.cmu.ac.th/ejournal/
Contributed Paper
Antioxidant and Antiglycation Activities of Some
Edible and Medicinal Plants
Khwanta Kaewnarin [a,b], Hataichanoke Niamsup [a,b], Lalida Shank [a,b] and
Nuansri Rakariyatham [a,b]*
[a] The Center of Excellence for Innovation in Chemistry (PERCH-CIC), Commission on Higher Education,
Ministry of Education, Department of Chemistry, Faculty of Science, Chiang Mai University,
Chiang Mai 50200, Thailand.
[b] Division of Biotechnology, Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand.
*Author for correspondence; e-mail: nuansri1@yahoo.com
Received: 14 November 2012
Accepted: 19 March 2013
ABSTRACT
Protein glycation and oxidative stress caused by chronic hyperglycemia are the
major factors in diabetic complications. In the attempt to search for natural remedies,
ethyl acetate and ethanol extracts from twenty Thai edible and medicinal plants were
assessed in terms of their phenolic and flavonoid contents as well as their antioxidant
and antiglycation activities. The highest amounts of phenolic and flavonoid compounds
were found in the ethanolic extract of the young leaves of Punica granatum followed by
those of Dimorcarpus longan and Mangifera indica, respectively. These three plant extracts
also exhibited the highest antioxidant activity. A high correlation between the antiglycation
activity and the phenolic and flavonoid contents was observed in all extracts. In addition,
five ethanolic extracts−−from Tamarindus indica, Psidium guajava, Mangifera indica,
Dimocarpus longan and Punica granatum young leaves−− were determined for their
concentrations required to inhibit 50% (IC50) of either glucose or methyl glyoxal-derived
glycation. P.granatum, M.indica and P.guajava extracts showed high antiglycation activity
in the BSA-glucose model, with IC50 values of 110.4, 214.4 μg/mL and 243.3 μg/mL,
respectively. The IC50 values of antiglycation activity in the BSA-methylglyoxal model
of M.indica (54.1 μg/mL), P.granatum (69.1 μg/mL) and D.longan (74.2 μg/mL) were
higher than that of the standard AGE inhibitor, aminoguanidine (91.2 μg/mL). These
results indicated that some Thai edible and medicinal plants possessed high contents of
phenolic and flavonoid and have potential applications towards the prevention of
glycation-associated diabetic complications.
Keywords: antioxidant, antiglycation, diabetic complications
1. INTRODUCTION
At the present, the number of diabetic
patients has rapidly increased, especially in
the Asia-Pacific region [1]. Diabetes mellitus,
a disorder characterized by hyperglycemia,
is caused by insulin deficiency and/or
insulin resistance. Prolonged hyperglycemia
plays a vital role in the development of chronic
diabetic complications such as retinopathy,
106 Chiang Mai J. Sci. 2014; 41(1)
cataracts, atherosclerosis, neuropathy, impaired
wounding and aging [2-4]. Numerous studies
on diabetes have reported that hyperglycemia
involves oxidative stress via glucose
autooxidation and an interruption of
the electron transport chain. Glucose
autooxidation catalyzed by transition metals
can generate superoxide radical (O2
⋅⋅
⋅⋅
⋅-) and
ketoaldehyde; by which the superoxide
radical will be converted to hydroxyl radical
(OH⋅⋅
⋅⋅
⋅) through the Fenton reaction [5-8].
The accelerated oxidation can result in cell
damage and induction of specific signaling
pathway, for example, the nuclear factor-κB
(NF-κB) leading to pro-inflammatory
cytokines [9-10]. The protein glycation is a key
molecular basis of diabetic complications
which results from chronic hyperglycemia.
In terms of the glycation mechanism, the
carbonyl group of reducing sugars reacts
non-enzymatically with the amino group of
proteins, nucleic acids and others molecules
[11-12] in order to initiate glycation (Amadori
or fructosamine products). Subsequently,
Amadori products undergo a series of
irreversible reactions forming highly reactive
carbonyl species (RCS), such as glyoxal,
methylglyoxal and 3-deoxy-glucosone [13].
Finally, these reactive carbonyls react with the
amino, sulfhydryl and guanidine functional
groups of intracellular and extracellular
proteins to form the stable advanced
glycation endproducts (AGEs). The reactive
carbonyl species can also be produced from
sugar glyoxidation contributing to the
AGE formation [14-15]. AGE products can
cross-link with long-lived proteins such as
collagen, lens crystallins, and other
biological molecules---haemoglobin, low-
density lipoprotein---leading to the altered
structures and functions of these proteins
in vivo [16-17]. Ahmed [18] reported that
the glycation of lens crystallins has been
considered as one of the major factors in
causing diabetic cataracts. Furthermore, one
of the most well-known AGEs contributing
towards diabetic atherosclerosis is glycated-
low density lipoprotein (LDL) [8, 19].
In recent years, many synthetic AGEs
inhibitors have been found to be
effective against AGEs formation, such as
aminoguanidine (AG), the most well-known
synthetic prodrug. However, their practical
applications are limited because of their
toxicity and severe side effects [12, 20].
Besides, some AGEs inhibitors contribute to
the pyridoxal sequestration causing vitamin
B6 deficiency in diabetic patients [11].
Currently, many plant extracts and purified
constituents have been demonstrated as able
to suppress AGE formation. Procyanidins,
extracted from cinnamon [12], as well as
caffeic acid and chlorogenic acid from mate
tea extracts [21], were shown to be the active
constituents responsible for the antiglycation
effect. Additionally, several scientific reports
have revealed that the antiglycation of plant
extracts can be attributed to the phenolic
compounds, which are correlated with their
free radical scavenging activities [12, 17,
22-25]. In previous studies, our teams have
investigated several Thai edible plants
which contain large amounts of bioactive
compounds, particularly phenolic compounds
that exhibit strong antioxidant activities
[26-27]. However, phytochemical data
of compounds involved in alleviating or
preventing diabetic complications are still
needed. For these reasons, this study aims to
evaluate the antioxidant and antiglycation
activities of various edible and medicinal plants
including the correlations with their total
phenolic and flavonoid contents.
2. MATERIALS AND METHODS
2.1 Plant Materials and the Preparation
of Crude Extracts
Plant materials (Table 1) were purchased
Chiang Mai J. Sci. 2014; 41(1) 107
from the local market in Chiang Mai,
Thailand during the period of April to
August, 2011. The plant materials were dried
at 50°C and powdered. The extraction was
prepared as described by Harborne [28]
with slight modifications. Three grams of
each sample were extracted with ethyl
acetate (50 mL, x3) over 1 h in a shaker at
room temperature. Ethyl acetate (EA) extract
was filtered through Whatman’s no. 1
filter paper. The dried residue was then
successively extracted with 80% (v/v)
ethanol (50 mL, x3). After filtration, the ethyl
acetate and ethanolic extracts (ET) were
filtered and allowed to evaporate and
lyophillize.
Table 1. Edible and medicinal plants used in this study.
Allium cepa
Allium ascalonicum
Allium sativum
Gynura divaricata
Gymnema inodorum
Coccinia grandis
Gynostemma pentaphyllum
Coriandrum sativum
Apium graveolens
Eryngium foetidum
Centella asiatica Urban
Cissus quadrangularis
Andrographis paniculata Wallex Nees
Clitoria ternatea
Musa sapientum
Tamarindus indica
Psidium guajava
Mangifera indica
Dimocarpus longan
Punica granatum
Common name
Onion
Shallot
Garlic
-
-
ivy gourd
jiaogulan
coriander
chinese celery
false coriander
Asiatic pennywort
-
king of bitter
blue pea
banana
tamarind
guava
mango
longan
pomegranate
Extracted part
Whole bulb
Whole bulb
Whole bulb
Leaves
Leaves
Leaves
Leaves
Leaves
Leaves
Leaves
Leaves
Stems
Leaves
Flowers
Flowers
Young leaves
Young leaves
Young leaves
Young leaves
Young leaves
2.2 Determination of Total Phenolic
Content
The total phenolic content of each extract
was assessed by the Folin-Ciocalteu method
with some modifications [26] and gallic acid
was used as the standard phenolic compound.
The extract which was redissolved in ethanol
(100 μL) was transferred to a test tube
containing 7.9 mL of distilled water.
The samples were mixed with 500 μL of the
Folin-Ciocalteu reagent and left to react for
5 min. The reaction mixture was neutralized
with the addition of 1.5 mL of 200g/L
sodium carbonate (Na2CO3), followed by
2 h incubation with constant shaking.
The absorbance was then measured at 760
nm. The total phenolic content was expressed
as mg gallic acid equivalent (GAE)/g sample.
2.3 Determination of Total Flavonoid
Content
Total flavonoid content was determined
by a colorimetric method [29] with slight
modifications and quercetin was used as
108 Chiang Mai J. Sci. 2014; 41(1)
the standard flavonoid. One half mL of the
extract was mixed with 2 mL of distilled
water, followed by addition of 0.15 mL of
50 g/L sodium nitrite (NaNO2). After 5 min
of reaction, 0.15 ml of 100 g/L aluminium
chloride (AlCl3) solution was added. The
reaction solution was mixed well and
incubated at room temperature for 15 min,
and the absorbance at 415 nm was measured.
Total flavonoid content was expressed as μg
quercetin equivalent (QE)/g sample.
2.4 In vitro Determination of Antioxidant
Activity by Using DPPH Radical
Scavenging Activity
1,1-Diphenyl-2-picrylhydrazyl (DPPH)
radical scavenging activity of different sample
extracts was determined [27]. One mL of
DPPH radical solution (0.1 mM DPPH⋅⋅
⋅⋅
⋅ in
methanol) was well mixed with 3 mL of the
extract and incubated for 30 min at room
temperature. The decrease in absorbance
caused by the proton donating property of
the active compounds was measured at
517nm. The percent DPPH radical scavenging
activity was calculated using the following
formula:
DPPH radical scavenging effect (%) =
[(Ao - A1)/Ao] × 100
where Ao represented the absorbance of
the control solution and A1 represented the
absorbance of the extract solutions.
2.5 In vitro Determination of
Antiglycation Activity in BSA-glucose
Model
Inhibition of Protein glycation method
was performed according to Matsuura et al.
[30] with some modifications. The reaction
mixture (2 mL) contained 800 μg/mL bovine
serum albumin (BSA), 200 mM D-glucose
and with/without the extract (1 mg/mL) in
phosphate buffer (50 mM, pH 7.4) in the
presence of 0.2g/L of sodium azide (NaN3).
The reaction mixture was incubated at
37°C for 7 days. The fluorescence intensity
was measured at an excitation wavelength of
370 nm and an emission wavelength of
440 nm with a Perkin Elmer LS-50B
spectrofluorometer. Aminoguanidine (AG)
(1 mg/mL) was used as a positive control.
Results were expressed as percent AGE
inhibition calculated using the following
equation:
Inhibition (%) = [(F0 - Ft )/F0
] × 100
where Ft and F0 represent the fluorescence
intensity of the sample and the control
mixtures, respectively. Different extract
concentrations (50-500 μg/mL) providing
50% AGE inhibition (IC50) were calculated
from the graph of inhibition percentage
against the extract concentration.
2.6 In vitro Determination of
Antiglycation Activity in the BSA-
methylglyoxal Model
The evaluation for the inhibition of the
middle stage of protein was performed
according to Peng et al. [12]. Thirty microliters
of 500 mM methylglyoxal (MGO) were
mixed with 300 μL of 10 mg/mL BSA in
the presence of 0.2 g/L of NaN3. The
BSA-methylglyoxal reaction mixture was
incubated at 37°C for 3 days with/without
various concentrations (50-500 μg/mL) of
the selected plant extracts. Aminoguanidine
(AG) (10-100 μg/mL) was used as a positive
control. The fluorescence intensity was
measured at an excitation wavelength of
370 nm and an emission wavelength of
420 nm with a Perkin Elmer LS-50B.
The percentage of the AGE inhibition was
calculated using the same equation as in the
BSA-glucose model.
Chiang Mai J. Sci. 2014; 41(1) 109
2.7 Statistical Analysis
All experimental results were presented
as means ± SD in triplicate. One way analysis
of variance (ANOVA) was applied
for comparison of the mean values. P value
< 0.05 was regarded as significant. The
correlation (r) between the two variants was
analyzed using the Pearson test. All statistical
analyses were performed using SPSS
software (SPSS 17.0 for windows; SPSS Inc.,
Chicago).
3. RESULTS AND DISCUSSION
3.1 Total Phenolic and Total Flavonoid
Contents
This study involved twenty Thai edible
and medicinal plants that are regularly
consumed and applied in traditional forms
of medicines in Thailand. Total phenolic
and flavonoid contents, antioxidant and
antiglycation activities of the extracts of
these plants were determined. The phenolic
content was determined by the Folin-
Ciocalteu method and expressed as mg gallic
acid equivalent (GAE) per g of dry sample.
Table 2 shows the content of phenolic
compounds in various plant extracts ranging
from 0.02 to 3.13 mg/g sample. Significant
differences (p<0.05) were found in all of
these amounts. High amounts of phenolic
compounds were found in ethanolic (ET)
fractions of P.granatum (3.13 mg/g), D.longan
(1.68 mg/g), M.indica (1.51 mg/g) and
the ethyl acetate (EA) fractions of D.longan
(1.20 mg/g) and P.granatum (1.11 mg/g),
respectively. The total flavonoid content in each
plant extract was also determined using a
colorimetric method and reported as the μg
quercetin equivalent (QE) per g of dried
sample. The results showed that the content
of the flavonoid range from 1.39 to 237 mg/
g. Significantly, the highest amount of
flavonoids was shown (p<0.05) in the ET
fraction of P.granatum (237 mg/g) followed
by D.longan (160 mg/g), M.indica (151 mg/g)
and EA fractions of D.longan (136 mg/g) and
M.indica (135 mg/g). It could be observed
that the young leaf extract of P.granatum
exhibited the highest amounts of total
phenolics and flavonoids. Moreover, the
ethanolic extracts of P.granatum, D.longan
and M.indica contained higher amounts of
phenolic compounds and flavonoids than
their ethyl acetate (EA) extracts. The results
correspond with Harborne’s work [28]
which reported that alcohol is a suitable
organic solvent for phenolic and flavonoid
extraction.
Table 2. Total phenolic and total flavonoid contents in the ethyl acetate (EA) and ethanolic
(ET) extracts of edible and medicinal plants.
Plants
A.cepa
A.ascalonicum
A.sativum
G.divaricata
G.inodorum
C.grandis
G.pentaphyllum
C.sativum
A.graveolens
E.foetidum
Total phenolic content
(mg GAE/g)
Total flavonoid content
(μg QE/g )
EA extract
0.04±0.0
0.04±0.0
ND
0.16±0.0
0.08±0.0
0.07±0.0
0.16±0.0
0.05±0.0
0.03±0.0
0.05±0.0
ET extract
0.04±0.0
0.10±0.0
0.02±0.0
0.40±0.0
0.38±0.0
0.18±0.0
0.13±0.0
0.09±0.0
0.14±0.0
0.07±0.0
EA extract
2.96±0.2
3.82±1.0
2.96±0.4
48.3±6.5
50.4±1.4
68.4±4.3
49.0±5.1
22.2±0.8
27.8±1.4
19.0±1.0
ET extract
8.49±0.2
6.16±0.2
1.39±0.0
78.6±7.2d
159±6.4b,c
51.3±4.9
26.3±3.2
15.4±0.4
40.5±0.7
9.26±2.0
110 Chiang Mai J. Sci. 2014; 41(1)
3.2 Antioxidant Activity
1,1-Diphenyl-2-picrylhydrazyl (DPPH) is
a stable free radical which is frequently used
in measuring antioxidant activities due to the
following strengths: its direct measurement
of inhibition, simplicity and quick analysis
[31]. Both solvent extracts were assessed
for the antioxidant activity using the DPPH
radical method and expressed as percent
DPPH⋅⋅
⋅⋅
⋅ inhibition (Table 3). Significant
differences (p<0.05) were found in the
antioxidant activity of the plant extracts.
Strong antioxidant activity was found in
both EA and ET fractions, especially those
of P.granatum (94.1% and 95.7%), D.longan
(94.3% and 95.5%), M.indica (93.9% and
94.8%) and P.guajava (94.6% and 93.5%).
The strong antioxidant activities of these
plant extracts are possible a result of the high
contents of phenolics and flavonoids which
have been shown to be highly antioxidant
[32-35]. Correlations between the antioxidant
activity and the phenolic and flavonoid
contents were investigated (Table 4).
There were strong correlations (r ET = 0.779
and r EA = 0.866, p<0.05) between antioxidant
activity and phenolic content for all
ethanolic (ET) and ethyl acetate (EA) extracts.
This relationship indicated that the free
radical scavenging activity of the plant extracts
was associated with the phenolic compounds.
This result agreed with previous studies
reporting that phenolic compounds in various
plant extracts are the major constituents with
free radical scavenging property to donate a
hydrogen atom from their phenolic hydroxyl
groups [25, 36-39]. This is similar to the results
presented in Thitilertdecha’s research [27],
which suggested that the antioxidant activities
of rambutan extracts were remarkably related
to their phenolic contents. Additionally, high
correlation (rET = 0.796) was observed
between antioxidant activity and the flavonoid
content in the ethanolic fractions of all plants.
Moderate correlation (rEA = 0.583) was
observed for their ethyl acetate (EA) fractions.
The findings showed that ethanol was a good
solvent for the extraction of antioxidant
substances. These correlations suggest that the
strong antioxidant activity present in these
plants possibly come from the phenolic
compounds.
Table 2. (Continue)
- Values are expressed as means ± SD.
- a-d Means in the column followed by different letters are significantly different (p<0.05)
- ND = not determined
Plants
C.asiatica Urban
C.quadrangularis
A.paniculata Wallex Nees
C.ternatea
M.sapientum
T.indica
P.guajava
M.indica
D.longan
P.granatum
Total phenolic content
(mg GAE/g)
Total flavonoid content
(μg QE/g )
EA extract
0.04±0.0
0.03±0.0
0.03±0.0
0.12±0.0
0.03±0.0
0.29±0.0d
0.14±0.0
0.74±0.0c
1.20±0.1a
1.11±0.1b
ET extract
0.16±0.0
0.04±0.0
0.05±0.0
0.26±0.0
0.11±0.0
0.15±0.0
0.69±0.1d
1.51±0.0c
1.68±0.2b
3.13±0.1a
EA extract
19.9±1.7
18.2±1.4
118±0.6c
50.3±1.6
9.46±0.9
130±3.9b
93.6±2.6d
135±4.6a,b
136±5.5a
33.2±1.9
ET extract
34.5±5.1
5.54±1.0
13.5±0.5
76.6±2.8
8.67±1.3
69.3±1.7
73.4±5.3
151±4.7c
160±2.1b
237±5.5a
Chiang Mai J. Sci. 2014; 41(1) 111
Table 3. Antioxidant and antiglycation activities of EA and ET plant extracts.
Plants
A.cepa
A.ascalonicum
A.sativum
G.divaricata
G.inodorum
C.grandis
G.pentaphyllum
C.sativum
A.graveolens
E.foetidum
C.asiatica Urban
C.quadrangularis
A.paniculata Wallex Nees
C.ternatea
M.sapientum
T.indica
P.guajava
M.indica
D.longan
P.granatum
EA extract
1.73±0.4
2.91±0.3
ND
31.3±0.1
87.9±0.7b
ND
11.0±0.6
6.64±0.1
1.91±0.1
8.82±0.4
9.64±0.3
4.00±0.2
0.64±0.1
12.6±1.0
6.12±0.1
23.4±1.8
94.6±0.2a
93.9±0.5a
94.3±0.1a
94.1±0.3a
ET extract
3.34±0.8
3.04±0.8
ND
60.7±3.4b
53.3±1.3
35.2±2.7
ND
28.6±0.4
18.7±0.6
8.87±0.5
59.7±4.8b
6.45±1.7
11.5±0.4
28.3±0.5
15.8±3.1
17.6±1.1
93.5±0.9a
94.8±0.2a
95.5±0.2a
95.7±0.2a
EA extract
58.1±6.6
49.8±1.7
7.19±1.4
97.6±0.7b,c
97.6±0.1b,c
99.6±0.3a
98.5±0.5a,b
82.3±2.9
88.0±0.6
81.0±1.1
82.2±4.7
80.6±0.6
89.6±0.6d
98.4±0.2a,b
45.7±1.3
99.4±0.4a
99.8±0.1a
99.8±0.1a
99.9±0.0a
99.8±0.0a
ET extract
71.7±0.4
78.7±1.3
8.06±1.8
91.6±0.7d
99.5±0.2a
95.9±2.1c
96.3±0.2a
85.7±2.4d
99.6±0.2a
61.8±1.6
95.6±1.8c
56.3±3.1
96.5±0.9b,c
99.9±0.4a
70.7±0.7
96.2±0.1c
99.8±0.0a
99.9±0.0a
99.8±0.0a
99.0±0.0a
DPPH radical scavenging activity
(% Inhibition)
Antiglycation activity
(% Inhibition)
- Values are expressed as means ± SD.
- a-d Means in the column followed by different letters are significantly different (p<0.05)
- ND = not determined
Table 4. The Pearson correlation coefficient of total phenolic and flavonoid contents with
antioxidant and antiglycation activities of plant extracts.
Phenolic content
Flavonoid content
Correlation
Antioxidant activity Antiglycation activity
EA extract
0.866
0.583
ET extract
0.779
0.796
EA extract
0.849
0.879
ET extract
0.864
0.796
112 Chiang Mai J. Sci. 2014; 41(1)
3.3 Antiglycation Activity
The antiglycation activity of plant extracts
was evaluated for the inhibition of advanced
glycation endproducts(AGEs) formation
based on the BSA/glucose system. The results
indicated that sixteen plants exhibited potential
antiglycation activity (> 80% inhibition)
(Table 3). Similarly to the antioxidant activity,
strong antiglycation activity was found
statistically in both the EA and ET extracts
(p<0.05), especially those of T.indica (99.4%
and 96.2%), P.guajava (99.8% and 99.8%),
M.indica (99.8% and 99.9%), D.longan (99.9%
and 99.8%) and P.granatum (99.8% and 99.0%).
This correlation was also evaluated (Table 4).
Data revealed substantial correlation of the
antiglycation activity of the plant extracts
with the phenolic(rET = 0.864 and rEA = 0.849)
and flavonoid contents (rET = 0.796 and rEA=
0.879, p<0.05). These results are noteworthy
not only because the phenolic and flavonoid
contents of these extracts show a positive
relationship with the antioxidant activity,
but also with the antiglycation property.
Many published studies have suggested that
the phenolic and flavonoid compounds in
plant extracts are responsible for the
antiglycation activity [12, 17, 22-25]. For
example, it has been reported that cinnamon
bark extract could inhibit the formation of
AGEs which is mainly attributed to its phenolic
constituents, such as catechin, epicatechin, and
procyanidin B2.
As a result of their strong antioxidant
and antiglycation activities, the ethanolic young
leaf extracts of 5 plants (T.indica, P.guajava,
M.indica, D.longan and P.granatum) were selected
for further investigation of their antiglycation
activity against glucose and methylglyoxal
models. In the BSA-glucose model, it was
found that P.granatum (IC50= 110 μg/mL) had
significantly stronger inhibitory activity than
M.indica and P.guajava extract (IC50= 214 μg/
mL and 243 μg/mL), respectively (p<0.05).
However, these extracts were found to be less
effective than aminoguanidine (IC50= 50.2 μg/
mL) which is the positive control.
The inhibitory effect of the selected plant
extracts on a BSA-methylglyoxal (MGO)
model was also reported (Figure 1(B)).
BSA-methylglyoxal model represented the
middle stage of protein glycation in which
sugar is oxidized to α-dicarbonyl compounds
such as methylglyoxal, glyoxal and 3-
deoxyglucosome, which are more reactive in
reacting with amino group of protein leading
to AGE formation [17]. The IC50 values
showed that M.indica extract (54.1 μg/mL) had
statistically higher antiglycation activity than
P.granatum and D.longan extract (69.1 μg/mL
and 74.2 μg/mL, respectively) (p<0.05).
In addition, these results indicated that the
ethanolic extracts of M.indica, P.granatum and
D.longan had significantly higher inhibitory
activity-against AGE formation induced by
methylglyoxal than aminoguanidine (IC50=
91.2 μg/mL) (p<0.05). This is likely the result
of the high contents of phenolic and
flavonoid compounds in these plant extracts.
It has been that reported P.granatum leaves
contain high amounts of tannins and phenolic
compounds [40], whereas Gil [41] has
reported the presence of phenolic apigenin
and luteolin glycosides in pomegranate
leaves [41]. This fact suggests that P.granatum
leave extracts were responsible for the
inhibition of AGE formation in the BSA-
methylglyoxal model.
Chiang Mai J. Sci. 2014; 41(1) 113
These results were consistent with a
previous study [12] on the correlation of
the antiglycation activities and the total
phenolic contents of bean extracts.
Interestingly, the young leaf extracts of
M.indica, P.granatum and D.longa displayed
significantly greater inhibitory activities than
amionguanidine aminoguanidine in the
BSA-methylglyoxal model which is likely
one of their principle mechanisms of the
inhibition in the AGE formation [39]. The
previous study demonstrated that several
phenolic compounds, such as catechin,
epicatechin, and procyanidin B2, and
phenol polymers, identified from the
subfractions of the aqueous cinnamon
extract displayed significant inhibitory
effects on the formation of AGEs [12]. Their
antiglycation activities were related to their
trapping abilities of the reactive carbonyl
species, such as methylglyoxal (MGO), an
intermediate reactive carbonyl of AGE
formation, of which proanthocyanidins
(condensed tannins) were shown to be more
effective scavenging reactive carbonyl
species than other isolated compounds.
Figure 1. Inhibitory effect of the selected plant extracts (A) on the formation of glycation in
BSA- glucose model (B) on the formation of glycation in BSA- methylglyoxal model.
Aminoguanidine was used as a positive control. Different superscripts indicate statistically
significant differences (p<0.05).
114 Chiang Mai J. Sci. 2014; 41(1)
Besides, Wu [24] has reported that flavonoids,
especially, luteolin and rutin, developed a more
significant inhibitory effect on methylglyoxal-
medicated protein modification. While, rutin,
quercetin and kaempferol were reported to
be effective at the last stage of protein
glycation in the BSA-glucose model.
4. CONCLUSIONS
The present study shows an evaluation
of the antiglycation and antioxidant
properties present in the extracts of 20
edible and medicinal plants. Most of the
ethanolic extracts from the plants contained
higher phenolics and flavonoids than their
ethyl acetate extracts. In addition, the
correlation was found between the
phytochemical compositions of the extracts
and their antiglycation and antioxidant
activities. Among these extracts, the ethanolic
extracts of T.indica, P.guajava, M.indica, D.longan
and P.granatum young leaves exhibited both
strong antiglycation and strong antioxidant
activities in vitro. The ethanolic extracts of
P.granatum, D.longan and M.indica showed
higher antiglycation activity in the BSA-
methylglyoxal model than the positive control,
aminoguanidine. Therefore, it is possible that
these edible and medicinal plants might
provide effective natural sources of treatment
against the glycation reaction and oxidative
stress found in diabetic patients.
ACKNOWLEDGEMENT
The authors are grateful to the Center
of Excellence for Innovation in Chemistry
(PERCH-CIC), the Commission on Higher
Education, Ministry of Education,
Department of Chemistry, Faculty of Science
and the Graduate School, Chiang Mai
University, Chiang Mai, Thailand for the
financial support of this research.
REFERENCES
[1] Chan J.C.N., Malik V., Jia W.,
Kadowaki T., Yajnik C.S., Yoon K.-
H. and Hu F.B., Diabetes in Asia:
Epidemiology, risk factors, and
pathophysiology, JAMA., 2009; 301:
2129-2140.
[2] Gugliucci A., Glycation as the glucose
link to diabetic complications, J. Am.
Osteopath. Assoc., 2000; 100: 621-634.
[3] M ndez J.D., Xie J., Aguilar-
Hern ndez M. and M ndez-
Valenzuela V., Trends in advanced
glycation end products research in
diabetes mellitus and its complications,
Mol. Cell Biochem., 2010; 341: 33-41.
[4] Brownlee M., Biochemistry and
molecular cell biology of diabetic
complications, Nature, 2001; 414: 813-820.
[5] Rolo A.P. and Palmeira M., Diabetes
and mitochondrial function: Role of
hyperglycemia and oxidative stress,
Toxicol. Appl. Pharmacol., 2006; 212:
167-178.
[6] Maritim A.C., Sanders R.A. and
Watkins III J.B., Diabetes, oxidative
stress, and antioxidants: A review, J.
Biochem. Mol. Toxicol., 2003; 17: 24-38.
[7] Choi S.-W., Benzie I. F.F., Ma S.-W.,
Strain J.J. and Hannigan B.M., Acute
hyperglycemia and oxidative stress:
Direct cause and effect?, Free Radical
Biol. Med., 2008; 44: 1217-1231.
[8] Packer L. and Sies H., Oxidative Stress
and Inflammatory Mechanisms in
Obesity, Diabetes, and the Metabolic
Syndrome, 1st Edn., CRC Press, New
York, 2007.
[9] Peyroux J. and Sternberg M.,
Advanced glycation endproducts
(AGEs): Pharmacological inhibition in
diabetes, Pathol. Biol., 2006; 54: 405-419.
[10] Jang D.S., Lee Y.M., Jeong I.H. and
Kim J.S., Constituents of the flowers
Platycodon grandiflorum with inhibitory
Chiang Mai J. Sci. 2014; 41(1) 115
activity on advanced glycation end
products and rat lens aldose reductase
in vitro, Arch. Pharm. Res., 2010; 33:
875-880.
[11] Singh R., Barden A., Mori T. and
Belin L., Advanced glycation end-
products: A review, Diabetol., 2001;
44: 129-146.
[12] Peng X., Chang K.-W., Ma J., Chen
B., Ho C.-T., Lo C., Chen F. and
Wang M., Cinnamon bark
proanthocyanidins as reactive
carbonyl scavengers to prevent the
formation of advanced glycation
endproducts, J. Agric. Food Chem.,
2008; 56: 1907-1911.
[13] Ngre-Salvayre A., Coatrieux C.,
Ingueneau C. and Salvayre R.,
Advanced lipid peroxidation end
products in oxidative damage to
proteins. Potential role in diseases and
therapeutic prospects for the
inhibitors, Brit. J. Pharmacol., 2008;
153: 6-20.
[14] Liu H., Liu H., Wang W. , Khoo C.,
Taylor J. and Gu L., Cranberry
phytochemicals inhibit glycation of
human hemoglobin and serum
albumin by scavenging carbonyls,
Food Funct., 2011; 2: 475-482.
[15] Puppala M. and Chandrasekhar A.,
Ellagic acid, a new antiglycation agent:
Its inhibition of N
ε
-(carboxymethyl)
lysine, Biochem. J., 2012; 442: 221-230.
[16] Ho S.-C., Wu S.-P., Lin S.-M. and
Tang Y.-L., Comparison of anti-
glycation capacities of several herbal
infusions with that of green tea, Food
Chem., 2010; 122: 768-774.
[17] Wu J.-W., Hsieh C.-L., Wang H.Y.
and Chen H.-Y., Phytochemical from
berries and grapes inhibited the
formation of advanced glycation
endproducts by scavenging reactive
carbonyls, Food Chem., 2009; 113: 78-84.
[18] Ahmed N., Advanced glycation
endproducts-role in pathology of
diabetic complications, Diabetes Res.
Clin. Pract., 2005; 67: 3-21.
[19] Hsieh C.-L., Lin Y.-C., Ko W.-S.,
Peng C.-H., Huang C.-N. and Peng
R.Y., Inhibitory effect of some
selected nutraceutic herbs on LDL
glycation induced by glucose and
glyoxal, J. Ethnopharmacol., 2005; 102:
357-363.
[20] Peng X., Zheng Z., Cheng K.-W., Shan
F., Ren G.-X., Chen F., and Wang M.,
Inhibitory effect of mung bean extract
and its constituent vitexin and
isovitexin on the formation of
advanced glycation end-products, Food
Chem., 2008; 106: 475-481.
[21] Gugliucci A., Bantos D., Schulze J.
and Souzza M., Caffeic and chlorogenic
acids in Ilex paraguariensis extracts are
the main inhibitors of AGE generation
by methylglyoxal in model proteins,
Fitoterapia, 2009; 80: 339-344.
[22] Kim H.Y. and Kim K., Protein
glycation inhibitory and antioxidative
activities of some plants in vitro, J.
Agric. Food Chem., 2003; 51: 1586-1591.
[23] Matsuda H., Wang T., Managi H. and
Yoshikawa M., Structural
requirements of flavonoids for
inhibition of protein glycation and
radical scavenging activities, Bioorg.
Med. Chem., 2003; 11: 5317-5323.
[24] Wu C.H. and Yen G.C., Inhibitory
effect of naturally occurring flavonoids
on the formation of advanced glycation
endproducts, J. Agric. Food Chem.,
2005; 53: 3167-3173.
[25] Ardestani A. and Yazdanparast R.,
Inhibitory effects of ethyl acetate extract
of Tercriun polium on In Vitro protein
glycation, Food Chem. Toxicol., 2007;
45: 2402-2411.
[26] Chenwithesuk A., Teerawutgulrag A.
116 Chiang Mai J. Sci. 2014; 41(1)
and Rakariyatham N., Screening of
antioxidant activity and antioxidant
compounds of some edible plants of
Thailand, Food Chem., 2005; 92: 491-497.
[27] Thitilertdecha N., Teerawutgulrag A.
and Rakariyatham N., Antioxidant and
antibacterial activities of Nephelium
lappaceum L. extracts, LWT-Food Sci.
Technol., 2008; 41: 2029-2035.
[28] Harborne J.B., Phytochemical Methods;
A Guide to Modern Techniques of Plant
Analysis, Chapman & Hall, London, 1998.
[29] Zhishen J., Mengcheng T. and
Jianming W. The determination of
flavonoid contents in mulberry and
their scavenging effects on superoxide
radicals, Food Chem., 1999; 64: 555-559.
[30] Matsuura N., Aradate T., Sasaki C.,
Kojima H., Ohara M., Hasegawa J.
and Ubukata M., Screening system for
the Maillard reaction inhibitor from
natural product extracts, J. Health
Sci., 2002; 48: 520-526.
[31] Mammadov R., Ili, P. and Ertem
Vaizogullar H., Antioxidant activity
and total phenolic content of Gagea
fibrosa and Romulea ramiflora, Iran J.
Chem. Chem. Eng., 2011; 30: 57-62.
[32] Rout S. and Banerjee R., Free radical
scavenging, anti-glycation and tyrosinase
inhibition properties of a polysaccharide
fraction isolated from the rind from
Punica granatum, Bioresource Technol.,
2007; 98: 3159-3163.
[33] Guo C.J., Yang J.J., Wei J.Y., Li Y.F.,
Xu J. and Jiang Y.G., Antioxidant
activities of peel, pulp and seed fractions
of common fruits as determined by
FRAP assay, Nutr. Res., 2003; 23:
1719-1726.
[34] Zheng G.M., Xu L.X., Wu P., Xie
H.H., Jiang Y.M., Chen F. and Wei
X.Y., Polyphenols from longan seeds
and their radical-scavenging activity,
Food Chem., 2009; 116: 433-436.
[35] Maisuththisakul P., Suttajit M. and
Pongsawatmanit R., Assessment of
phenolic content and free radical-
scavenging capacity of some Thai
indigenous plants, Food Chem. 2007;
100: 1409-1418.
[36] Tang S.Y., Whiteman M., Peng Z.F.,
Jenner A., Yong E.L. and Halliwell B.,
Characterization of antioxidant and
antiglycation properties and isolation
of active ingredients from traditional
Chinese medicines, Free Radical Biol.
Med., 2004; 36: 1575-1587.
[37] Porkorny J., Yaniohlirva N. and
Gordon M.H., Antioxidants in Food:
Practical Applications, CRC Press,
Cambridge, 2001.
[38] Sawa T., Nakao M., Akaike T., Ono
K. and Maeda H., Alkylperoxyl
radical-scavenging activity of various
flavonoids and other phenolic
compounds: Implications for anti-
tumor-promotor effect of vegetables,
J. Agric. Food Chem., 1999; 47: 397-402.
[39] Wang W., Yagiz Y., Buran T.-J.,
Nunes C.-N. and Gu L., Phytochemical
from berries and grapes inhibited the
formation of advanced glycation end-
products by scavenging reactive
carbonyls, Food Res. Int., 2011; 44:
2666-2673.
[40] Cavalcanti R.N., Navarro-D az H.J.,
Santos D.T., Rostagno M.A. and
Meireles M.A.A., Supercritical carbon
dioxide extraction of polyphenols
from pomegranate (Punica granatum
L.) Leaves: Chemical composition,
economic evaluation and chemometric
approach, J. Food Res., 2012; 1: 282-294.
[41] Gil M.I., Tom s-Barber n F.A., Hess-
Pierce B., Holcroft D.M. and Kader
A.A., Antioxidant activity of
pomegranate juice and its relationship
with phenolic composition and
processing, J. Agric. Food Chem., 2000;
48: 4581-4589.
