Bali Medical Journal (Bali Med. J.) 2015, Volume 4, Number 1: 37-40
P-ISSN.2089-1180, E-ISSN.2302-2914

AQUEOUS EXTRACT OF BALINESE PURPLE SWEET
POTATO (IPOMOEA BATATAS L.) PREVENTS OXIDATIVE
STRESS AND DECREASES BLOOD INTERLEUKIN-1
IN HYPERCHOLESTEROLEMIC RABBITS
1

I M. Jawi, 2A. Wiwiek Indrayani, 2I W. P. Sutirta-Yasa

1

Departement of Pharmacology, Faculty of Medicine, Udayana University, Bali-Indonesia
Departement of Clinical Pathology, Faculty of Medicine, Udayana University, Bali-Indonesia

2

Background: Hypercholesterolemia can cause oxidative stress, endothelial dysfunction and
atherosclerosis. Anthocyanin can prevent oxidative stress, it will decrease the inflammation by
decreasing the pro-inflammatory cytokine in animal models. Purple sweet potato in Bali has been
proven of having high anthocyanins content. The aim of these study was to prove the ability of
aqueous extract of Balinese purple sweet potato (Ipomoea batatas L.) in decreasing the blood
interleukin-1 level in hypercholesterolemic rabbits. Methods: Subjects of this study were 18 male
adult rabbits divided into 3 groups with randomized post-test only control group design. Group 1
rabbits were given standard diet as a control group. Group 2 rabbits were given high cholesterol diet.
Group 3 rabbits were given aqueous extract of Balinese purple sweet potato 4 ml/Kg.BW/day and high
cholesterol diet. After 60 days of treatment, the blood level of total cholesterol, MDA and interleukin1 were measured as post test examination. The data were analysed by using anova. Results: The
results showed significant increases of blood total cholesterol, MDA, and interleukin-1 in group 2
(p<0.05). In group 3 the increases of blood total cholesterol and MDA levels were sligthly lower than
the group 2 (p<0.05). Group 3 also showed significantly lower of blood interleukin-1 levels than those
in group 2 (p<0.05). Conclusion: From this finding, it can be concluded that aqueous extract of
Balinese purple sweet potato can decrease oxidative stress and decrease the level of interleukin-1 in
hypercholesterolemic rabbits.
Keywords: purple sweet potato; oxidative; stress, IL-1; rabbits
INTRODUCTION
Atherosclerosis is a vascular disorder that is
the leading cause of cardiovascular diseases in the
world. Atherosclerosis is a chronic inflammatory
process involving the proinflammatory interleukin
in vascular endothelium.1,2 Inflammation that
occurs in endothelial usually preceded by the
presence of endothelial dysfunction caused by
oxidative stress. Oxidative stress will cause changes
in intracellular signaling resulting in the activation
of nuclear factor kappa B (NF-kB), which will lead
to increased production of inflammatory mediators
such as interleukin-1, interleukin-2 and other
proinflammatory interleukin.3 Plants foods that
contain anthocyanins are supposed to prevent
oxidative stress in order to prevent atherosclerosis,
through hypolipidemic effect and antioxidant in
vivo and in vitro and anti-inflammatory.4-6
Address of Correspondence: I M. Jawi
Department of Clinical Pharmacology, Faculty
of Medicine Udayana University, Bali-Indonesia
Email: made_jawi@yahoo.co.id

Purple sweet potato tubers from several
countries have demonstrated varying levels of
anthocyanin and has antioxidant properties.4-6
Purple sweet potato tubers in Bali have been proven
to contain high anthocyanins and has been shown to
be an antioxidant in animals model.6-8
Aqueous extract of purple sweet potato tuber
is one of the simple products manufactured and has
been shown to be hypolipidemic and can increase
total antioxidant in hypercholesterolemic rabbits,8
It is expected aqueous extract of purple sweet
potato tuber can reduce levels of interleukin-1,
therefore, it can inhibits vascular endothelial
inflammation. To prove this hypothesis the study
conducted in rabbits given high-cholesterol diet for
60 days.
MATERIALS AND METHODS
The study design was a randomized post-test
only control group design with 29 local Balinese
male rabbits aged 4 months, were divided into 3
groups, 9 rabbit of each group. Group 1 is the
negative control group (only given a standard diet).

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37

Bali Medical Journal (Bali Med. J.) 2015, Volume 4, Number 1: 37-40
P-ISSN.2089-1180, E-ISSN.2302-2914

Group 2 was given a high cholesterol diet. Group 3
is given a high cholesterol diet and aqueous extract
of purple sweet potato tubers with a dose of 4 ml /
kg bw/day by mixing with food, as the treatment
group.
High cholesterol diet is a special diet, that
consists of a mixture of rabbit food pellets brand
gold blend and 1 egg yolk/day for one rabbit, for 60
days of treatment. After 60 days of treatment blood
test is conducted on all rabbits. Blood is taken from
a vein in the rabbit ear for examination of blood
total cholesterol, MDA and the levels of
interleukin-1. MDA examination conducted by the
TBARS method, while the examination of the
interleukin-1 by Elisa Kit. The data were analyzed
by applying Oneway-Anova statistical test.
RESULTS
Blood Total Cholesterol of Rabbits
Data of blood total cholesterol were presented
in Figure 1.
250

aqueous extract of purple sweet potato tuber, occurs
decreased of MDA significantly (p<0.05) compared
with group 2. This research shows that the state of
hypercholesterolemia caused increased MDA.
Provision of aqueous extract of purple sweet potato
tuber can prevent the increase of MDA due to
hypercholesterolemia.
Interleukin-1 of the Blood
The result of interleukin-1 level in the blood
of rabbits with high cholesterol diet increase
significantly compared to the control group and
treatment group (p<0.05). The average levels of
interleukin-1 in the control group were 0.064±0.008
pg/ml, whereas in high cholesterol group was 0.069
± 0.002 pg/ml. The interesting result of this study is
after the high-cholesterol diet with aqueous extract
of purple sweet potato tuber the titer of interleukin1 was decreased (0.063 ± 0.002pg/ml) significantly
compared with the group with high cholesterol diet
(p<0.05). The comparison of results of the
interleukin-1 can be seen in Figure 3.

150

0.068

100

Group 1

50

Group 2

0

Group 3
Group of Rabbit

Group 1

Blood IL-1 Level (pg/ml)

0.07

total cholesterol (mg/dl)

200

Group 2

0.066

Group 3

0.064
0.062
0.06

Figure 1
Average of Blood Total Cholesterol in 3 Groups of
Animals
Note: Group 1 is the control group, Group 2 is the
group given high-cholesterol diets and Group 3 is
the group given high-cholesterol diets and water
extract of purple sweet potato tubers.
Blood MDA Level
Average blood MDA level data were presented in
Figure 2
blood MDA (mmol/L)

10

Group 1
Group 2

5

Group 3

0
Groups of Rabbit

Figure 2
Average Blood MDA Level of Rabbit
Figure 2 shows group 2 (given high-cholesterol
diet) an increase in blood MDA significantly
(p<0.05), compared to control (Group 1) and the
treatment group (Group 3). In the group given

Groups of Rabbit

Figure 3
Comparison of blood levels of interleukin-1 of
rabbit
DISCUSSION
Figure 1 shows the average of blood total
cholesterol increased in the rabbits given highcholesterol diet for 60 days. The increase was
highly significant (p <0.05), compared with group 1
and group 3. The average of total cholesterol in
group 1 (control) was 100.200 ± 2.00, group 2 was
215.400 ± 8.49, and group 3 was 144.133 ± 4.34.
In this study, high-cholesterol feeding for 60
days led to an increase in total cholesterol, MDA
and interleukin-1 levels were significantly (p
<0.05). Hypercholesterolemia is happening will
cause an increase in ROS through activation of
NADPH oxidase enzyme,9 resulting in an increase
in MDA.10,11 Feeding high cholesterol along with
aqueous extract of purple sweet potato tuber caused
a decrease in total cholesterol, MDA and
interleukin-1 were significantly (p<0.05).
Relatively high anthocyanin aqueous extract
of purple sweet potato tuber,7 can prevent oxidative
stress, both directly and indirectly.12 Additionally

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38

Bali Medical Journal (Bali Med. J.) 2015, Volume 4, Number 1: 37-40
P-ISSN.2089-1180, E-ISSN.2302-2914

anthocyanin can improve lipid profiles,13,14 through
inhibition of cholesterol absorption in the
gastrointestinal tract, decreased production of
lipoproteins in the liver and modulates LDL
receptors.14
The results in this study are consistent with
several studies examining the benefits of
anthocyanins from various plants, in the vital
organs such as; to reduce oxidative stress in the
liver tissue,15 and vascular endothelial.16 Research
on tissue culture incubated with high anthocyanin
from extracts of black rice, there was a significant
reduction in oxidative stress by reducing the
formation of superoxide.10
The reduced of blood total cholesterol levels
due to the aqueous extract of purple sweet potato
tuber will prevent the oxidative stress resulting in
decreased blood MDA. As a result of the reduction
in oxidative stress would improve endothelial
function, preventing inflammation in the
endothelium resulting in decreased interleukin-1.
Interleukin-1 is a proinflammatory cytokine that
can increase the expression of various inflammatory
mediators through the activation of NF-kB.17
Anthocyanins and other flavonoids may prevent the
activation of NF-kB and therefore reduces the
production
of
various
proinflammatory
cytokine.18,19
CONCLUSION
From these results it can be concluded that,
aqueous extract of purple sweet potato tuber has an
ability to prevent oxidative stress in the blood and
decrease the interleukin-1 by decreasing total
cholesterol in rabbits fed with high cholesterol diet.
ACKNOWLEDGEMENTS
The authors would like to thank to Research &
Development Unit of Faculty of Medicine Udayana
University, Bali-Indonesia for financially supported
of this research.
REFERENCES
1. Arenillas, J.F., Alvarez-Sabin, J., Molina, C. A.
2008. Progression of Symptomatic Intracranial
Large Artery Athrosclerosis is Associated with
a Proinflammatory State and Impaired
Fibrinolysis. Stroke, 39:1456.
2. Phipps, R. P. 2000. Athrosclerosis: The
Emerging Role of Inflammation and CD 40-CD
40 Ligand System. Proc Natl Acad Sci U S A.
97: 6930-6932.
3. Han K H, Matsumoto A, Shimada K,
Sekikawa M, Fukushima M.2007. Effects of
anthocyanin-rich purple potato flakes on
antioxidant status in F344 rats fed a cholesterolrich diet. Br J Nutr. 98(5):914-21.
4. Kano M, Takayanagi T, Harada K, Makino K,
and Ishikawa F. 2005. Antioxidative Activity of

Anthocyanins from Purple Sweet Potato,
Ipomoea batatas Cultivar Ayamurasaki. Biosci
Biotechnol. Biochem.69(5):979-88.
5. Lachman J, Hamouz K, Sulc M, Orsak M,
Pivec V, Hejtmankova A, Dvorak P. 2009.
Cultivar differences of total anthocyanins and
anthocyanidins in red and purple-fleshed
potatoes and their relation to antioxidant
activity. Food Chemistry. 2009. 144:836-43.
6. Jawi, I M, Suprapta D N, Dwi S U, Wiwiek
I.2008. Ubi Jalar Ungu Menurunkan Kadar
MDA dalam Darah dan Hati Mencit setelah
Aktivitas Fisik Maksimal. Jurnal Veteriner
Jurnal Kedokteran Hewan Indonesia. 9(2):6572.
7. Suprapta D N, Antara M, Arya N, Sudana M,
Danuaji A S,Sudarma M. 2004. Kajian Aspek
Pembibitan, Budidaya dan Pemanfaatan umbiumbian sebagai sumber pangan alternatif.
Laporan Hasil Penelitian. Kerjasama BAPEDA
Propinsi Bali dengan Fakultas Pertanian UNUD.
8. Jawi I M dan Budiasa K. 2011. Ekstrak Air
Umbi Ubijalar Ungu
Menurunkan Total
Kolesterol
Serta
Meningkatkan
Total
Antioksidan pada Darah Kelinci. Jurnal
Veteriner, Jurnal Kedokteran Hewan Indonesia.
12 (2); 120-5.
9. Madamanchi N R, Vendrov A, Runge MS.
2004. Oxidative Stress and Vascular Disease.
Arterioscler Throm Vasc Biol. 25(1): 29-38.
10. An-Na C, Hua-Lin W, Hung-I Y, Chi-Shuen C,
Hui-Chiao L, and Wei-Chin
L. 2006.
Antioxidant Effect of Black Rice Extract
through the Induction of Superoxide Dismutase
and Catalase Activities. Lipid. 41(8):797-803.
11. Chen W P, Mao T J, Fan L, Zhou Y H, Yu J,
Jin Y, Hou P C. 2011. Effect of purple sweet
potato on lipid metabolism and oxidative stress
in hyperlipidemic rats. Chinese. 40(4):360-4.
12. Padda M S. 2006. “Phenolic Composition and
Antioxidant Activity of Sweetpotatoes (
Ipomoea batatas, L)”. (A Dissertation).
Submitted to the Graduate Faculty of the
Louisiana State University and Agricultural and
Mechanical College in partial fulfillment of the
requirement for the degrre of Doctor of
Philosphy in The Department of Horticulture.
13. Murkopic M. 2004. Effects of Elderberry Juice
on Fasting and Postprandial Serum Lipids and
Low-Density Lipoprotein Oxidation in Healthy
Volunteers: a Randomized, Doubled-Blind,
Placebo-Controlled Study. European Journal of
Clinical Nutrition. 58(2):244-9.
14. Valcheva-Kuzmanova
S, Kuzmanov
K,
Tancheva S, Belcheva A.2007. Hypoglycemic
effect of Aronia Melanocorpa Fruit Juice in
Streptozotocin-Induced Diabetic Rats. Methods
Find Exp Clin Pharmacol. 29(2):101.

Open access: www.balimedicaljournal.org and www.ojs.unud.ac.id

39

Bali Medical Journal (Bali Med. J.) 2015, Volume 4, Number 1: 37-40
P-ISSN.2089-1180, E-ISSN.2302-2914

15. Guzik T J, Olszanecki R, Sadowski J, Kapelak
B, Rudzinski P, Jopek A, Kawczynska A,
Ryszawa N, Loster J, Jawien J, CzesnikiewiczGuzik M, Channon K M, Korbut R. 2005.
Superoxide Dismutase Activity and Expression
in Human Venous and Arterial Bypass Graft
Vessels.Journal
of
Physiology
and
Pharmacology. 56(2): 313-323.
16. Speciale A, Canali R, Chirafisi J, Saija A,
Virgili F, and Cimino F. 2010. Cyanidin-3-Oglucoside Protection against TNF-α-Induced
Endothelial Dysfunction: Involvement of
Nuclear Factor-κB Signaling. J. Agric. Food
Chem. 58 (22):12048–54.
17. Curti M L R, Jacob P, Borges M C, Rogero M
M, and Ferreira S R G. 2011. Studies of Gene
Variants Related to Inflammation, Oxidative
Stress, Dyslipidemia, and Obesity: Implications
for a Nutrigenetic Approach. Journal of Obesity,
Volume 2011 (2011), Article ID 497401, 31
pages

18. Ahmed S, Wang N, Hafeez B B, Cheruvu V K,
and Haqqi T M. 2005. Punica granatum L.
Extract Inhibits IL-1β–Induced Expression of
Matrix Metalloproteinases by Inhibiting the
Activation of MAP Kinases and NF-κB in
Human Chondrocytes In Vitro. J Nutr. 135(9):
2096–2102.
19. Rasheed Z, Akhtar N, Anbazhagan1 A N,
Ramamurthy S, Shukla M, and Haqqi T M.
2009. Polyphenol-rich pomegranate fruit extract
(POMx) suppresses PMACI-induced expression
of pro-inflammatory cytokines by inhibiting the
activation of MAP Kinases and NF-κB in
human
KU812
cells.
Journal
of
Inflammation.6(1):9255-61.

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