全 文 ：山药零余子多糖抗氧化活性及
对糖尿病小鼠降血糖作用
梁潇 1，黄月琴 2，陈建平 2*，郝朋伟 3 （1.中国
人民解放军总医院，北京 100853；2.淮南师范
学院化学与化工系，安徽淮南 232001；3.安徽
理工大学理学院，安徽淮南 232001）
摘 要 提取山药零余子中的多糖，探讨其体
外抗氧化活性和对糖尿病小鼠的降血糖作用。
结果表明，山药零余子多糖的还原力随着浓度
的提高显著增强，对 DPPH·和·OH 具有较强
的清除能力，并呈一定的剂量关系，4.0 mg/ml
剂量时清除率分别可达到 91.15%和 89.06%；
山药零余子多糖能显著降低造模小鼠的血糖，
且大剂量的山药零余子多糖降糖更明显。山药
零余子多糖具有较好的抗氧化性和降血糖作
用，这为安全天然食品抗氧化剂、降血糖药剂
的开发提供了新来源。
关键词 山药零余子；多糖；抗氧化活性；降血
糖作用
基 金 项 目 淮 南 师 范 学 院 重 点 基 金
（2011LK76zd）； 淮 南 师 范 学 院 青 年 基 金
（2010LK13）。
作者简介 梁潇（1986-），女，安徽淮南人，硕
士，药师，从事药物分析研究，E-mail：liangxiao-
0520@sina.cn。 * 通讯作者。
收稿日期 2015-03-16
修回日期 2015-06-08
Antioxidant Activity of Polysaccharides in Yam
Bulbils and Their Hypoglycemic Effect in Diabetic
Mice
Xiao LIANG1, Yueqin HUANG2, Jianping CHEN2*, Pengwei HAO3
1. Chinese PLA General Hospital, Beijing 100853, China;
2. Department of Chemistry and Chemical Engineering, Huainan Normal College, Huainan 232001, China;
3. College of Science, Anhui University of Science & Technology, Huainan 232001, China
Supported by Key Project of Huainan Normal College (2011LK76zd); Youth Fund of
Huainan Normal College (2010LK13).
*Corresponding author. E-mail: liangxiao0520@sina.cn
Received: March 16, 2015 Accepted: June 8, 2015A
Agricultural Science & Technology, 2015, 16(7): 1332-1335
Copyright訫 2015, Information Institute of HAAS. All rights reserved Agricultural Basic Science and Technology
Y am bulbils refer to the axillarybuds of Dioscorea oppositaThunb [1]. They are commonly
known as “Shanyao Dan”, which are
oval or elliptical and in the diameter of
0.4-2.0 cm. The outer skin of yam bul-
bils is pale yellow and has fine wrin-
kles. In the center of tops, there are
hard stem scars. Their section is gray
to brown. The yam bulbils have light
smell and are not bitter, but taste
sticky. They mainly contain starch,
polysaccharides (including mucoid
substances and glycoproteins), pro-
teins, free amino acids and other ac-
tive ingredients [2]. Yam bulbils are a
kind of herb with high medicinal value,
and they are edible and have high
medical value[3]. Yam bulbils have rich
resources, and their yield can reach
3 000 -6 000 kg/hm2. Only a small
proportion of yam bulbils are used for
cooking and breeding, and most of
them are discarded as waste. In order
to further enhance the development
value of yam bulbils and increase the
added value of yam industry, the an-
tioxidant activity and hypoglycemic ef-
fect of polysaccharides in yam bulbils
were studied in this paper, thereby lay-
ing theoretical basis for the compre-
hensive development and utilization of
yam bulbils.
Materials and Methods
Materials
The tested yam bulbils were pur-
chased from Jiaozuo City, Henan
Province. The ICR mice, of SPF grade
and in weight of 20 -25 g, were pur-
chased from the Beijing Weitong Lihua
Laboratory Animal Technology Co.,
Ltd.
Methods
Polysaccharides in yam bulbils
The crushed yam bulbils were soaked
in hot water at 60-80 ℃ for 5 h. The
extract was collected and concentrat-
ed by reducing pressure to an appro-
priate volume. The proteins in the ex-
Abstract The polysaccharides in yam bulbils were extracted, and their antioxidant
activity and hypoglycemic effect in diabetic mice were discussed. The results
showed that the antioxidant activity of polysaccharides in yam bulbils was signifi-
cantly enhanced with the increase of concentration; they showed a strong scaveng-
ing ability against DPPH· and ·OH, and the scavenging ability was dose dependent
to some extent; the scavenging rates reached 91.15% and 89.06% respectively
when the dose reached 4.0 mg/ml; the polysaccharides in yam bulbils significantly
reduced the blood glucose in model rice, and the hypoglycemic effect of large-dose
polysaccharides was more obvious. The polysaccharides in yam bulbils has good
antioxidant activity and hypoglycemic effect, which provides a new source for devel-
opment of safe and natural food antioxidants and blood sugar-lowering agents.
Key words Yam bulbils; Polysaccharides; Antioxidant activity; Hypoglycemic effect
DOI:10.16175/j.cnki.1009-4229.2015.07.003
Agricultural Science & Technology2015
tract were removed by the Sevag
method, and then the crude polysac-
charides were precipitated with
ethanol.
Modeling of experimental animal
and treatments A total of 80 ICR
mice were selected. They were first
bred in test environment for 4 d. After
fasted for 12 h, the mice were injected
once with 150 rag/kg of alloxan into
their abdomen. They were bred for
another 3 d. After a 6-h fasting, the
fasting blood glucose in mice was de-
termined. The mice with fasting blood
glucose higher than 10 mmol/L were
selected as diabetic mice.
The ICR male mice were divided
into 5 groups, including normal control
group, diabetic model group and three
polysaccharides dose treatment
groups. There were 10 mice in each
group. In the three polysaccharides
dose treatment groups, 10, 20 and 30
rag/kg of polysaccharides from yam
bulbils were given to mice respectively
by gavage. In the normal control group
and diabetic model group, same-
amount distilled water was given to the
mice by gavage. The gavage was car-
ried out once a day and lasted for 30
consecutive days. The body weights
and fasting blood glucose in mice were
determined at different times. The glu-
cose tolerance in mice was deter-
mined after the test ended. After a 6-h
fasting, the mice were supplied with 25
g/kg of glucose by oral administration,
and then, the blood glucose contents
in mice were determined 0, 1 and 2 h
after the administration respectively[4].
Reducing power of polysaccharides
in yam bulbils Certain amounts (2.5
ml) of sample solutions at different
concentrations were added to tubes.
Subsequently, a certain amount (2.5
ml) of phosphate buffer (0.2 mol/L, pH
6.6) and a certain amount (2.5 ml) of
1% potassium hexacyanoferrate solu-
tion were added to each of the tubes.
After bathed in water at 50 ℃ for 20
min, the tubes were cooled rapidly and
added with certain amounts (2.5 ml) of
10% trichloroace-tic acid solution. Af-
ter the mixing, the tubes were cen-
trifuged at 5 000 r/min for 10 min. Sub-
sequently, certain amounts (2.5 ml) of
supernatants were removed to other
new tubes. A certain amount (2.5 ml)
of distilled water and a certain amount
(0.5 ml) of 0.1% ferric chloride solution
were added to each of the new tubes
in turn. After a complete mixing, the
mixtures were stood for 10 min. With
distilled water as the reference solu-
tion, the absorbances of the mixtures
were determined at a wavelength of
700 nm. The larger the absorbance is,
the stronger the reducing power is[5].
Scavenging ability of polysaccha-
rides in yam bulbils against DPPH·
A certain amount (2 ml) of sample so-
lution was mixed with a certain amount
(2 ml) of DPPH solution (0.000 1 mol/L,
dissolved in 95% ethanol). After
placed in shadow at room temperature
for 20 min, the mixture was centrifuged
at 1 000 r/min for 10 min, and the ab-
sorbance (Di ) of supernatant was de-
termined at 517 nm. For the blank
group, a certain amount (2 ml) of sam-
ple solution was mixed with a certain
amount (2 ml) of 95% ethanol. The ab-
sorbance (Dj ) of the mixture was de-
termined at 517 nm. For the control
group, a certain amount (2 ml) DPPH
solution was mixed with a certain
amount (2 ml) of distilled water, and
the absorbance (Dc) of the mixture
was determined at the wavelength of
517 nm. The same-volume distilled
water and 95% ethanol was treated as
blank for zeroing. The scavenging rate
was calculated according to the follow-
ing formula:
Scavenging rate (DPPH·) = [1-
(Di-Dj ) / Dc ] × 100%[6].
Scavenging ability of polysaccha-
rides in yam bulbils against·OH
In the sample group, certain amounts
of phosphate buffer (0.4 mol/L, 1 ml,
pH 7.4), phenanthroline solution (2.5
mmol/L, 1 ml), ferrous sulfate solution
(2.5 mmol/L, 1 ml), H2O2 (0.02 mol/L,
0.5 ml) and sample solution (1 ml)
were mixed together. In the injury
group, the sample solution was re-
placed by 1 ml of distilled water. In the
blank group, the sample solution and
H2O2 were replaced by 1.5 ml of dis-
tilled water. The mixtures were all
bathed in water at 37 ℃ for 1 h, and
then their absorbances at 536 nm
were determined rapidly [7]. The scav-
enging rate of polysaccharides against
·OH was calculated according to fol-
lowing formula:
Scavenging rate (·OH) = (D0-D2)/
(D1-D2) × 100%[6].
Wherein, D0 refers to the ab-
sorbance of the ·OH system added
with sample solution and H2O2; D1
refers to the absorbance of the·OH
system added with sample solution
added with sample solution but without
H2O2; D2 refers to the absorbance of
the·OH system added with H2O2 but
without sample solution.
Blood glucose determination The
blood in angular vein of experimental
mice was collected, and for the deter-
mination of fasting blood glucose, the
venous blood of mice fasted for 6 h
was collected. And then the serum
samples were prepared, and the blood
glucose contents were determined
with the glucose oxidase-peroxidase
method.
Data analysis The test data were
expressed as mean ± standard devia-
tion. The one-way ANOVA was con-
ducted using Minitab 16, and the com-
parison among treatment groups was
performed using Duncans multiple
range tests.
Results and Analysis
Reducing power of polysaccha-
rides in yam bulbils
Reducing power is an important
indicator reflecting the antioxidant ca-
pacity of certain substance, and the
strength of reducing power is an im-
portant parameter for antioxidant ac-
tivity of polysaccharides. The ab-
sorbances of polysaccharides samples
from yam bulbils at the wavelength of
700 nm can indirectly reflect the size of
the anti-oxidative capacity of polysac-
charides. As shown in Fig.1, with the
increase of polysaccharides concen-
tration, the absorbances were in-
creased gradually, and the reducing
power of polysaccharides was also
trended to be increased; when the
polysaccharides concentration was 5
mg/ml, the absorbance was highest,
and the reducing power was also
strongest.
Scavenging ability of polysaccha-
rides in yam bulbils against DPPH·
Fig.2 showed that the polysac-
charides solutions at different concen-
trations all had a certain scavenging
effect on DPPH·, and the scavenging
rate was increased with the increase of
concentration. When the yam bulbil
extract concentration was 4.0 mg/ml,
1333
Agricultural Science & Technology 2015
Table 1 Effect of polysaccharides from yam bulbils on fasting blood glucose in mice of each treatment group
Treatment Mousenumber
Dose
mg/kg
Blood glucose content
before modeling∥mmol/L
Blood glucose content after
modeling∥mmol/L
Blood glucose content
after therapy∥mmol/L
Normal control 10 0 5.53±0.64 aA 6.15±0.57 aA 6.09±0.72 aA
Model control 10 0 6.12±0.78 aA 15.32±0.64 bB 15.08±0.73 dB
Polysaccharides of yam bulbils 10 10 5.92±0.76 aA 15.28 ± 0.52 bB 14.23±0.53 cB
10 20 5.76±0.57 aA 15.95±0.64 cB 13.89±0.70 cB
10 30 5.95±0.76 Aa 16.03±0.61 cB 12.71±1.06 bB
Different lowercase letters in the same column indicate significant differences at the 0.05 level; different capital letters in the same column
indicate significant differences at the 0.01 level.
Fig.3 Scavenging ability of polysaccharides
from yam bulbils against·OH
the scavenging rate of DPPH· was
91.15% . The regression analysis
showed that the relationship between
scavenging effect of polysaccharides
from yam bulbils on DPPH · and
polysaccharides concentration was in
line with a linear equation model:
y=22.994x+10.2429(r2=0. 9946).
Scavenging ability of polysaccha-
rides in yam bulbils against·OH
Hydroxyl radical is the most reac-
tive oxygen in body, and its excessive
accumulation can cause a variety of
pathological changes. Polysaccha-
rides can provide hydrogen atom,
which can combine with hydroxyl radi-
cal to form water, thereby scavenging
free radicals. As shown in Fig.3, the
polysaccharides systems at different
concentrations all had a certain scav-
enging effect on·OH, and the scav-
enging effect was enhanced with the
increase of polysaccharides concen-
tration. When the polysaccharides
concentration was 4.0 mg/ml, the
scavenging rate of ·OH reached
89.06%.
Effect of polysaccharides in yam
bulbils on fasting blood glucose in
mice
Table 1 showed that there were
no significant differences in fasting
blood glucose among control group,
model group and treatment groups be-
fore the modeling. After the modeling,
the blood glucose content in the nor-
mal control group was all significantly
lower than those in the other groups.
After the therapy, the blood glucose
contents in mice of the three treatment
groups were all reduced, and the
decrement was more obvious in the
high dose (30 mg/kg) treatment group.
It suggests that the polysaccharides
from yam bulbils can effectively reduce
the blood glucose levels in diabetic
mice.
Conclusions and Discus-
sion
The oxidative damage caused by
free radicals is related to the patho-
genesis of many diseases. Human
can reduce the free radical level in
body through the proper intake of
substances with antioxidant activity,
preventing lipid peroxidation. Lipid
peroxidation is closely related to ag-
ing, and even can induce many dis-
eases[8]. The results of this study show
that the polysaccharides from yam
bulbils have significant antioxidant
activity and strong reducing power,
and when their concentration was
4.0 mg/ml, the scavenging rates of
DPPH· and ·OH were 91.15% and
89.06%, respectively.
The mechanism of alloxan induc-
ing diabetes has been well known. Al-
loxan can selectively destroy pancre-
atic β cells, resulting in reduced secre-
tory cell number, swelling cells and in-
creased vacuoles in pancreas islets. In
the destruction of β cells in pancreas
islets, free radicals play a vital role [9].
This study finds that the polysaccha-
rides from yam bulbils can significantly
reduce blood glucose contents in allox-
an-induced diabetic mice, which may
be related to increased secretion of in-
sulin, improved cellular functions in
damaged β cells and scavenging of
excess free radicals.
Using the chemical model, this
study finds that the polysaccharides
from yam bulbils have relatively strong
antioxidant and hypoglycemic effect,
and they provide a new resource for
development of safe, effective, nutri-
tious and natural antioxidants and
blood glucose-reducing agents, which
will not only improve farmers’ income,
but also turn yam bulbils into treasure.
References
[1] ZHAO B(赵冰). New cultivation technol-
ogy of Dioscorea opposita thumb(山药
栽培新技术)[M]. Beijing: Golden Shield
Press (北京: 金盾出版社), 1998.
[2] DU HQ(都恒青). Arrangement and study
on common Chinese herbal varieties
Fig.1 Reducing power of polysaccharides
from yam bulbils
Fig.2 Scavenging ability of polysaccharides
from yam bulbils against DPPH·
1334
Agricultural Science & Technology2015
(Continued from page 1324)
Responsible editor: Tingting XU Responsible proofreader: Xiaoyan WU
creased. Among the 4 kinds of sub-
strates, the alkaline phosphatase ac-
tivity was highest in the substrate M3.
During the nursing of watermelon
seedlings, the urease activity in rhizo-
spheric substrate was positively relat-
ed to shoot dry weight and total nitro-
gen content; the neutral phosphatase
activity was positively related to root
dry weight and total phosphorus con-
tent; the alkaline phosphatase activity
was positively related to pH value in
rhizospheric substrate.
In the first 10 d since the emer-
gence of watermelon seedlings, the
total nitrogen content and total phos-
phorus content were reduced rapidly;
the total nitrogen content and total
phosphorus content showed no signif-
icant changes from day 10 to day 30. It
suggested that the nitrogen and phos-
phorus in the substrate had basically
been exhausted in the first 10 d since
the emergence of watermelon
seedlings, and right amounts of ex-
ogenous nitrogen and phosphorus
should be supplemented timely to
maintain the normal growth of
seedlings.
References
[1] LIU WW (刘雯雯), YAO T (姚拓), SUN
LN (孙丽娜 ). The feasibility of spent
mushroom substrate as a kind of micro-
bial fertilizer carrier (菌糠作为微生物肥
料载体的研究)[J]. Journal of Agro-En-
vironment Science(农业环境科学学报),
2008, 27(2): 787-790.
[2] XIE JL(谢嘉霖), LIU RH(刘荣华), YE QF
(叶启芳 ), et al. Researches into media
EC and determination conditions (无土
栽培基质电导率和 pH 值测定条件的研
究) [J]. Journal of Anhui Agricultural Sci-
ences (安徽农业科学 ), 2006, 34 (3):
415-416.
[3] ZHAO LP(赵兰坡), JIANG Y(姜岩). Dis-
cussion on methods for determination of
soil phosphatase activity(土壤磷酸酶活
性测定方法的探讨)[J]. Chinese Journal
of Soil Science(土壤通报), 1986, 17(3):
138-141.
[4] LI FD(李阜棣). Soil Microbiology(土壤微
生物学 ) [M]. Beijing: China Agriculture
Press(北京: 中国农业出版社), 1996.
[5] National Bureau of Standards(国家标准
局 ). GB 7173-1987 Method for the de-
termination of soil total nitrogen (semi-
micro Kjeldahl method)(土壤全氮测定
法(半微量开氏法)). Beijing: Beijing Agri-
cultural University(北京: 北京农业大学),
1987.
[6] Ministry of Agriculture of the Peoples
Republic of China(中华人民共和国农业
部). GB 9837-88 Method for determina-
tion of soil total phosphorus(土壤全磷测
定法 (碱熔-钼锑抗分光光度法)). Bei-
jing: Chinese Academy of Agricultural
Sciences(北京: 中国农业科学院), 1988.
[7] STAMPS RH, MR EVANS. Growth of
Dieffenbachia maculate Camille. in
growing media containing sphagnum
peat or coconut coir dust[J]. Horticulture
Science, 1997, 32(5): 844-847.
[8] JONER EJ, JAKOBSEN I. Growth and
extracellular phosphatase activity of
arbuscular mycorrhizal hyphae as influ-
enced bysoil organic matter [J]. Soil Bi-
ology and Biochemistry, 1995, 27 (6):
1153-1159.
[9] ZHU LIXIA, ZHANG JIA EN. Review of
studies on interactions between root
exudates and rhizospheric microorgan-
isms[J]. Ecol Environ, 2003, 12(1): 102-
105(in Chinese).
[10] JAW M, BENDING GD, WHITE PJ.
Biological costs and benefits to plant-
microbe interactions in the rhizosphere
[J]. Journal of Experimental Botany,
2005, 56: 417-418.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Responsible editor: Tingting XU Responsible proofreader: Xiaoyan WU
(Northern China) (Second Volume) (常
用中药材品种整理和质量研究(北方篇):
第 二 册 ) [M]. Beijing: Beijing Medical
University & Chinese Peking Union
Medical College Associated Press (北
京: 北京医科大学中国协和医科大学联
合出版社), 1995.
[3] SUN F (孙锋), GU WY (谷文英), DING
XL (丁霄霖). Study on extraction tech-
nology of polysaccharide from Diosco-
rea opposita Thunb (山药粗多糖的提取
工艺 ) [J]. Journal of Food Science and
Biotechnology (食品与生物技术学报 ),
2006, 25(3): 79-83.
[4] VOGEL HG. Pharmacology Laboratory
Manual: New Drug Discovery and
Pharmacological Evaluation (药理学实
验指南 : 新药发现和药理学评价 ) [M].
Beijing: Science Press (北京 : 科学出版
社), 2001: 699-700.
[5] LUO ZY (罗祖友 ), YAN FW (严奉伟 ),
XUE ZH(薛照辉), et al. The anti-oxida-
tive effect of polysaccharide from Am-
pelopsis grossedentata (藤茶多糖的抗
氧化作用研究)[J]. Food Science(食品科
学), 2004, 25(11): 291-295.
[6] ZHA XQ, WANG JH, YANG XF. Antiox-
idant properties of polysaccharide frac-
tions with different molecular mass ex-
tracted with hot-water from rice brain[J].
Carbohydrate Polymers, 2009, 78 (3):
570-575.
[7] JIN M (金鸣), CAN YX (蔡亚欣), LI JR
(李金荣 ), et al. 1, 10-phenanthroline-
Fe2+ oxidative assay of hydroxyl radical
produced by H2O2/Fe2+ (邻二氮菲-Fe2+
氧化法检测 H2O2/Fe2+产生的羟自由基
[J]. Progress in Biochemistry and Bio-
physics (生物化学与生物物理进展 ),
1996, 23(6): 553-555.
[8] ZHU SY (朱淑云 ), DONG Y (董英 ),
ZHANG HH (张海晖), et al. Enzymatic
hydrolysis of milk thistle meal protein
and antioxidation of hydrolysates (水飞
蓟粕蛋白的酶解及其酶解物抗氧化活性
研究 )[J]. Chinese Cereals and Oils As-
sociation (中国粮油学报), 2011, 26(2):
68-72.
[9] YANG SC(杨锁成), MENG J(孟杰), XU
ZC (胥志才). Mechanism of preventive
and therapeutic effect of Xiaokekangtai
on experimental diabetes in rats (消渴
康泰对大鼠实验性糖尿病防治作用的机
理研究 ) [J]. Chinese Journal of Tradi-
tional Medical Science and Technology
(中国中医药科技), 2000, 7(2): 77-78.
1335