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REVIEW
Sweet Potato (Ipomoea batatas [L.] Lam) - A Valuable Medicinal Food:
A Review
Remya Mohanraj and Subha Sivasankar
Department of Biotechnology, Aarupadai Veedu Institute of Technology,
Vinayaka Missions University, Kancheepuram, India.
ABSTRACT Ipomoea batatas (L.) Lam, also known as sweet potato, is an extremely versatile and delicious vegetable that
possesses high nutritional value. It is also a valuable medicinal plant having anti-cancer, antidiabetic, and anti-inflammatory
activities. Sweet potato is now considered a valuable source of unique natural products, including some that can be used in the
development of medicines against various diseases and in making industrial products. The overall objective of this review is to
give a bird’s-eye view of the nutritional value, health benefits, phytochemical composition, and medicinal properties of sweet
potato. Specifically, this review outlines the biological activities of some of the sweet potato compounds that have been
isolated, the pharmacological action of the sweet potato extract, clinical studies, and plausible medicinal applications of sweet
potato (along with a safety evaluation), and demonstrates the potential of sweet potato as a medicinal food.
KEY WORDS: anti-cancer activity antidiabetic activity antioxidant activity phytochemical composition sweet
potato 4-Ipomeanol
INTRODUCTION
Over the past few decades, the search for plant-based
medicines has occupied many research groups. Al-
though a lot of research is focused on medicinal herbs, it
should not be overlooked that many vegetables and fruits
also possess medicinal properties. Ipomoea batatas (L.)
Lam, commonly known as sweet potato (Fig. 1) belonging to
the family Convolvulaceae, is an important root vegetable
which is large, starchy, and sweet tasting.
1,2
The plant is a
herbaceous perennial vine, bearing alternate heart-shaped
or palmately-lobed leaves and medium-sized sympetalous
flowers. The edible tuberous root is long and tapered with a
smooth skin. It is valued for its short growing period of 90 to
120 days, high nutritional content, and its sweetness.
I. batatas has played an important role as an energy and
phytochemical source in human nutrition and animal feeding.
The plant has significant medicinal importance and various
parts of the plant are used in traditional medicine. The leaves
are used to treat type 2 diabetes by Akan tribes of Ghana,
3
and in the treatment of inflammatory and/or infectious oral
diseases in Brazil.
4
In regions of Kagawa, Japan, a variety of
sweet potato has been eaten raw to treat anemia, hyperten-
sion, and diabetes.
5
The stems of I. batatas were used for
treatment of prostatitis.
6
The Monpa ethnic groups of Ar-
unachal Pradesh, India, use the tubers of sweet potato as a
staple food and the leaves as fish feed.
7
Sweet potato, which originated in Central America, is now
widely cultivated and consumed throughout the world.
8,9
European explorers introduced the crop to Africa and India
by the early 1500s, China by 1594, and Taiwan and Miyako
Island in Japan by 1597.
10–12
Sweet potato ranks seventh
among almost all food crops worldwide, with an annual
production of 115 million metric tons.
13
Approximately 92%
of world’s sweet potato supply is produced in Asia and the
Pacific Islands: 89% of which is grown in China.
14
With the above background in mind, this review aims at
providing an insight into the nutritional value, health ben-
efits, phytochemical composition, biological activities and
medicinal properties of sweet potato, and demonstrates the
potential of sweet potato as a medicinal food.
Biology and nutritional value of I. batatas
I. batatas is grown as an annual plant by vegetative
propagation using either storage roots or stem cuttings. The
stem is cylindrical and its length depends on the growth habit
of the cultivar and the availability of water in the soil. The
leaves are simple and spirally arranged alternatively on the
stem. Their color can be green, yellowish-green, or can have
purple pigmentation in part or all of the leaf blades. The
storage roots are the commercial part of the sweet potato
plant.
15
The color of the smooth skin of the root tuber ranges
between yellow, orange, red, brown, purple, and beige. Its
Manuscript received 25 February 2013. Revision accepted 16 April 2014.
Address correspondence to: Remya Mohanraj, PhD, Department of Biotechnology,
Aarupadai Veedu Institute of Technology, Vinayaka Missions University, Rajiv Gandhi
Salai (OMR), Paiyanoor 603 104, Kancheepuram District, Tamil Nadu, India. E-mail:
remyam@gmail.com
JOURNAL OF MEDICINAL FOOD
J Med Food 17 (7) 2014, 733–741
#Mary Ann Liebert, Inc., and Korean Society of Food Science and Nutrition
DOI: 10.1089/jmf.2013.2818
733
flesh ranges from beige to white, red, pink, violet, yellow,
orange, and purple. Sweet potato varieties with white or pale
yellow flesh are less sweet and moist than those with red,
pink, or orange flesh.
16
Sweet potato is used as a staple food, a root vegetable
(including its fleshy roots, tender leaves, and petioles), a snack
food, animal feed, a source for industrial starch extraction and
fermentation, and for various processed products.
17–20
Sweet
potato is high in nutritional value, with the exception of pro-
tein and niacin. It provides over 90% of nutrients per calorie
required for most people.
21,22
Roots are a valuable source
of carbohydrates, vitamins (providing 100% of the rec-
ommended daily allowance [RDA] for vitamin A and 49% of
the RDA for vitamin C), and minerals (providing 10% of the
RDA for iron and 15% of the RDA for potassium).
21,23
Besides simple starches, sweet potatoes are rich in com-
plex carbohydrates, dietary fiber, iron, and vitamin content
such as beta-carotene (a pro-vitamin A carotenoid), vitamin
B
2
, vitamin C, and vitamin E.
24
Pink, yellow, and green
varieties are also high in beta-carotene. The nutritional value
of sweet potato is presented in Table 1.
25
Orange-fleshed
sweet potatoes may be one of nature’s unsurpassed sources
of beta-carotene. Several recent studies have shown that the
sweet potato has superior ability to raise blood levels of
vitamin A. This benefit may be particularly true for children.
In several studies from Africa, sweet potatoes were found to
contain between 100–1,600 micrograms of retinol activity
equivalents (RAE) of vitamin A in every 3.5 ounces; en-
ough, on an average, to meet 35% of all vitamin A needs. In
many cases, sweet potatoes contain enough RAE to meet
over 90% of vitamin A needs.
For those who are involved in strenuous jobs, sweet po-
tato is a good source of carbohydrates and it is rich in vi-
tamins and minerals. For those suffering from stomach
cancer, a diet based on the sweet potato is beneficial.
26
Research has also shown that phytonutrients in sweet po-
tatoes may be able to help lower the potential health risk
posed by free radicals.
27
Starch is considered to be the main component of the sweet
potato root, followed by simple sugars such as sucrose, glu-
cose, fructose, and maltose.
28
Sweet potato leaves are indeed
more nutritious than the tuber itself. The leaves contain ap-
preciable amount of nutrients (crude protein, crude fat, crude
fiber, ash, carbohydrates, moisture contents, and energy),
vitamins (vitamin A and vitamin C), mineral elements (zinc,
potassium, sodium, manganese, calcium, magnesium, and
iron), low levels of toxicants (phytic acid, cyanide, tannins,
and total oxalate), and may be included in diets to supplement
dietary allowances of essential nutrients.
29
Health benefits of I. batatas
Root tuber. Sweet potato is one of the average calorie
starch foods and provides 90 calories/100 g vs. 70 calories/
100 g of other types of potatoes (Solanum tuberosum). The
tuber, however, contains no saturated fats or cholesterol and
is a rich source of dietary fiber, anti-oxidants, vitamins, and
minerals. Its energy content mainly comes from starch, a
complex carbohydrate. Sweet potato has a higher amylose to
the amylopectin ratio when compared to S. turberosum.
Amylose raises the blood sugar levels slowly in comparison to
simple sugars, and is recommended as a healthy food sub-
stance, even for patients with diabetes.
The tuber is an excellent source of flavonoids, phenolic
compounds such as beta-carotene, and vitamin A. A 100 g tuber
provides 14187 IU of vitamin A and 8509 lgofb-carotene.
The value is one of the highest in the root-vegetables cate-
gory. These compounds are powerful natural antioxidants.
Vitamin A is also required by the body to maintain the in-
tegrity of healthy mucus membranes and skin. It is a vital
FIG 1. Sweet potato tuber and leaf.
Table 1. Nutritional Value of Sweet Potato
Nutritional value per 100 g
Energy 360 kJ (86 kcal)
Carbohydrates 20.1 g
Starch 12.7 g
Sugars 4.2 g
Dietary fiber 3.0 g
Fat 0.1 g
Protein 1.6 g
Vitamin A equivalent 709 lg (89%)
- beta-carotene 8509 lg (79%)
- lutein and zeaxanthin 0 lg
Thiamine (vitamin B
1
) 0.1 mg (9%)
Riboflavin (vitamin B
2
) 0.1 mg (8%)
Niacin (vitamin B
3
) 0.61 mg (4%)
Pantothenic acid (vitamin B
5
) 0.8 mg (16%)
Vitamin B
6
0.2 mg (15%)
Folate (vitamin B
9
)11lg (3%)
Vitamin C 2.4 mg (3%)
Vitamin E 0.26 mg (2%)
Calcium 30.0 mg (3%)
Iron 0.6 mg (5%)
Magnesium 25.0 mg (7%)
Phosphorus 47.0 mg (7%)
Potassium 337 mg (7%)
Sodium 55 mg (4%)
Zinc 0.3 mg (3%)
734 MOHANRAJ AND SIVASANKAR
nutrient for visual acuity. Consumption of natural vegetables
and fruits rich in flavonoids helps protect from lung and oral
cavity cancers. The tubers are packed with many essential
vitamins such as pantothenic acid (vitamin B5), pyridoxine
(vitamin B6), and thiamin (vitamin B1), as well as niacin and
riboflavin. These vitamins are essential in the sense that the
body requires them from external sources in order to be re-
plenished. These vitamins function as co-factors for various
enzymes during metabolism. Sweet potato is a rich source of
vital minerals such as iron, calcium, magnesium, manganese,
and potassium that are essential for enzyme, protein, and
carbohydrate metabolism.
2
Shoot. Sweet potato leaves are high in lutein
30
which is
said to have a number of benefits for the eye, especially in
the prevention of age-related macular degeneration and
cataracts.
31
Sweet potato leaves are rich in potent antioxi-
dants and also vitamin C, which helps fight free radicals,
thus preventing premature aging and disease. They boost
the immune system and help prevent infections and diseases.
The polyphenolics present in the leaves showed various
kinds of physiological functions, radical scavenging activity,
antimutagenic activity, anticancer, antidiabetes, and anti-
bacterial activity in vitro and in vivo, which may be helpful
for maintaining and promoting human health. Sweet potato
leaves are a physiologically functional food that offers pro-
tection from diseases linked to oxidation such as cancer, al-
lergies, aging, HIV, and cardiovascular problems.
32
Phytochemistry and biological activity
The major phytochemicals present in the leaves of
sweet potato are triterpenes/steroids, alkaloids, anthraqui-
nones, coumarins, flavonoids, saponins, tannins, and phenolic
acids.
4
Sweet potatoes also contain specific phytochemicals
such as quercetin and chlorogenic acid that act to fight cancer
and protect the heart. They are rich in beta-carotene, which is
an interceptor of free radicals. Carotenoids have antioxidant
capabilities and reduce or inhibit mutagenesis in cells, and
terpenoids reduce low-density lipoprotein (LDL) cholesterol
levels and act as anticarcinogens. Thus, eating certain foods
such as sweet potatoes may contribute to protective levels
against cancers.
33
Anthocyanins. Genes in purple sweet potatoes (IbMYB1
and IbMYB2) are activated to produce the purple antho-
cyanin pigments responsible for the rich purple tones of
the flesh. The purple-fleshed sweet potato anthocyanins—
primarily peonidins and cyanidins—have important anti-
oxidant and anti-inflammatory properties, particularly when
passing through our digestive tract. They may be able to
lower the potential health risk posed by heavy metals and
oxygen radicals.
24
They may also be used as part of an anti-
hypertensive diet and may prevent atherosclerosis. As they
contain abundant nutrients, minerals, and functional poly-
phenols, purple sweet potatoes can be used as a functional
food material.
34
Sweet potato leaves are consumed primarily
in the islands of the Pacific Ocean and in Asian and African
countries, whereas limited consumption occurs in the United
States.
35
Phenolics. Alkaloids, phenolic compounds, and glyco-
lipids are the most common biologically-active constituents
of I. batatas. Different polyphenolic compounds 4-O-
caffeoylquinic acid, 1,3-di-O-caffeoylquinic acid (Fig. 2)
and 3,5-di-O-caffeoylquinic acid, possessing potent anti-
oxidant activities, have been isolated by chromatographic
methods from methanolic and hydromethanolic extracts of
I. batatas tuber flour.
36
These compounds possess a broad
range of pharmacological properties including hepatopro-
tectant, anti-bacterial, antihistamine, and other biological
effects.
37
These compounds are also inhibitors of HIV rep-
lication
38
and exhibit hypoglycemic,
39
radical scavenging,
40
and antimutagenic
41
activities. The stem also contains three
feruloylquinic acids and small amounts of at least four
caffeoyl-feruloylquinic acids.
42
Caffeoylquinic acid derivatives. From the sweet potato
leaf, the caffeoylquinic acid derivatives such as 3-mono-O-
caffeoylquinic acid (Chlorogenic acid [ChA]), 3,4-di-O-
caffeoylquinic acid (3,4-diCQA), 3,5-di-O-caffeoylquinic
acid (3,5-diCQA), 4,5-di-O-caffeoylquinic acid (4,5-diCQA),
3,4,5-tri-O-caffeoylquinic acid (3,4,5-triCQA), and Caffeic
acid (CA) have been isolated (Fig. 3). These compounds have
demonstrated antimutagenicity.
43
They were also found to
prevent proliferation of human cancer cells arising from
stomach cancer, colon cancer, and promyelocytic leukemia
cell.
44
Coumarins. The roots of I. batatas contain the couma-
rins aesculetin,
45
scopoletin, and umbelliferon which have
anti-coagulation properties and inhibit HIV replication.
46
Scopoletin also possesses hepatoprotective,
47
antioxidant,
48
spasmolytic,
49
and acetylcholinesterase inhibitory activi-
ties,
50
as well as inhibited proliferation by inducing apoptosis
of human adrogen-independent prostate adenocarcinoma
cells (PC3).
51
Scopoletin is one of the phytoalexins of
I. batatas.
52
Vitamin C, caffeic acid, flavonoids such as rutin,
quercetin,
53
tiliroside, astragalin, rhamnocitrin, rhamnetin,
and kaempferol,
54
as well as cyanidins and peonidins
40,55–61
are also found in this species.
Triterpenes. The bioactive triterpenes found in I. bata-
tas are: boehmeryl acetates, which act as ovipositional
stimulants for the sweet potato weevil; Cylas formicarius
elegantulus (Summers);
62
friedelin, which demonstrates
FIG 2. Structures of compounds isolated from sweet potato tubers.
SWEET POTATO AS MEDICINAL FOOD 735
good activity against S. aureus, compared with ampicillin
and amoxicillin, and good antifungal activity against
Pseudallescheria boydii.
63,64
b-amyrin acetate showed
pronounced antinociceptive properties in the writhing test
and formalin test in mice.
64,65
Furanoterpenoids. A group of 9-carbon furanoterpenoids
(1-Ipomeanol, 4-Ipomeanol, 1,4-Ipomeadiol, and Ipomeanine
[Fig. 4]) have been isolated from sweet potato tissue infected
with Fusarium solani.
66,67
4-Ipomeanol is a well-known cy-
totoxic metabolite of F. solani-infected sweet potatoes which
was first isolated in 1972 by Boyd and co-workers.
68
The list of biologically active compounds from sweet
potato, along with their pharmacological actions, is shown
in the flowchart in Figure 5.
Pharmacological properties of I. batatas
Ipomoea species are used in different parts of the world
for the treatment of several diseases, such as diabetes, hy-
pertension, dysentery, constipation, fatigue, arthritis, rheu-
matoid diseases, hydrocephaly, meningitis, kidney ailments,
and inflammations. They also possess antimicrobial, anal-
gesic, spasmolitic, spasmogenic, hypoglycemic, hypoten-
sive, anticoagulant, anti-inflammatory, psychotomimetic,
and anticancer activities.
37
Sweet potato is potent in the fight
against cancer. It is rich in beta-carotene, which is good in
fighting free radicals. Fluid and electrolyte balance is
maintained by sweet potatoes.
I. batatas is good for cardiovascular health.
41
It is also
used for treatment of tumors of the mouth and throat, asthma,
bug bites, burns, catarrh, ciguatera, convalescence, dyslactea,
fever, nausea, renosis, splenosis, stomach distress, and whit-
lows.
69
Leaf decoctions are used as an alterative, aphrodisiac,
astringent, bactericide, demulcent, fungicide, laxative, and
tonic.
5
Tuber flour of sweet potato was found to potentially
prevent ethanol-induced gastric ulceration by suppressing ede-
ma formation and partially protecting gastric mucosa wrinkles
and to heal wounds.
70
Because of its proven anti-ulcerative
activity, it could be considered when treating gastric ulcers.
71
Antioxidant activity. The total antioxidant capacity of
sweet potato has been reported to be 42.94% as compared
to ascorbic acid.
4
The total antioxidant activity of purple-
fleshed sweet potatoes was higher than the white-fleshed.
Their total phenolic content can serve as a useful indicator
FIG 3. Structures of compounds
isolated from sweet potato leaves.
FIG 4. Structures of furanoterpenoids isolated from F. solani in-
fected sweet potatoes.
736 MOHANRAJ AND SIVASANKAR
for the antioxidant activities of sweet potatoes.
72
Total
phenolic content has been found to be highest in the leaves
and in the stem end of the roots of sweet potato.
73
One study
shows the antioxidant activity in purple sweet potatoes as
3.2 times higher than that of a type of blueberry. Surpris-
ingly, sweet potatoes have potent antioxidant capacity in all
of their parts. Recent research has shown different genes to
be at work in the flesh versus skin of the sweet potato pro-
ducing different concentrations of anthocyanin antioxidants.
A recent study established baseline data on the total
phenolic content and antioxidant activities of five sweet
potato varieties grown in the Philippines including Dakol,
Emelda, Haponita, PSBSP, and Violet. Antioxidant activi-
ties were highest for Dakol. However, Haponita had the best
inhibitory action on linoleic acid oxidation. Methanolic
sweet potato extracts had higher radical scavenging activity,
reducing power and oxidation inhibition than a-tocopherol
and higher iron-chelating capacity than ethylenediamine
tetraacetic acid (EDTA).
74
The total antioxidant strength of
raw sweet potato measured in terms of oxygen radical ab-
sorbance capacity is 902 lmol TE/100 g.
Dong et al., studied the total antioxidant activity by
DPPH (1,1-diphenyl-2-picrylhydrazyl) staining, reducing
power method, metal ion-dependent hydroxyl radical, ferric
thiocyanate (FTC) method, and protection of calf thymus
DNA against hydroxyl radical-induced damage on sweet
potato storage root mucilage. He suggested that the muci-
lage might contribute its antioxidant activities against both
hydroxyl and peroxyl radicals.
27
Antidiabetic activity. Sweet potato exhibits potent anti-
diabetic property, and its activity was shown to be higher
than that of diabense, a standard drug for treating diabetes. A
study has revealed that consumption of sweet potato, a high-
polyphenol diet, for 7 days can modulate antioxidative status
and decrease exercise-induced oxidative damage and pro-
inflammatory cytokine secretion.
75
Researchers found that
the protein content of the flesh of the sweet potato was higher
than that of the peel. This suggests that the entire vegetable
could play a role in lowering blood glucose in diabetics: the
peel, as processed into a nutritional supplement like Caiapo;
and the flesh, as a simple addition to the everyday diet.
Adiponectin is a protein hormone produced by fat cells.
People with diabetes tend to have lower levels of adiponectin,
and sweet potato extracts have been shown to significantly
increase adiponectin levels in persons with type 2 diabetes.
In a study involving rats to determine sweet potato’s effects
on several markers of diabetes, the vegetable showed signifi-
cant abilities to decrease some of the more harmful markers.
Using white-fleshed sweet potatoes for the study, the rats
showed impressive improvement in pancreatic cell function,
lipid levels, and glucose management. They also showed de-
creased insulin resistance in just eight weeks. Improved insu-
lin sensitivity was also observed in a human study when sweet
potatoes were added to the diet.
76
Other research has con-
firmed that sweet potatoes are a low-glycemic index (GI)
food, which could be good for use by diabetics. With further
research in this area, it may be possible to recommend that
FIG 5. Biologically active compounds from I. batatas and their
pharmacological actions.
SWEET POTATO AS MEDICINAL FOOD 737
people with diabetes or insulin resistance consume sweet
potatoes or use its extracts to help control blood glucose. This
therapy should cost less than conventional drugs, and it may
have fewer side effects.
77
Anticancer activity. Researchers have found that eating
sweet potatoes will decrease the risk of breast, colorectal,
gallbladder and kidney cancer. A recent study evaluating the
risk factors for kidney cancer death included 47,997 males
and 66,520 females aged 40 years and older. Taking into
account medical history, anthropometry, dietary, and life-
style considerations over the 10-year study, the researchers
concluded that eating sweet potatoes and potatoes regularly
was associated with a decreased risk of the disease.
78
4-Ipomeanol from infected sweet potatoes is reported to
possess cytotoxic and anticancer properties.
79
It was the first
agent to be developed by the National Cancer Institute based on
a biochemical-biological rationale as an anticancer agent tar-
geted specifically against lung cancer.
80
Several human tumor
types, including many non-small cell lung lines and the MCF 7
breast cancer line, as well as its doxorubicin-resistant variant
are relatively sensitive to 4-Ipomeanol
81
.Becauseofthe
specific lung toxicity 4-Ipomeanol is being tested as a new
drug for the treatment of lung carcinoma. On the other hand, 4-
Ipomeanol is metabolized by liver cells too. It was recently tested
in phase II studies in patients with hepatocellular carcinoma
82,83
and it showed hepatotoxicity. Since, 4-Ipomeanol is reported to
be present only in infected sweet potatoes, its occurrence is
unlikely in normal tubers that are consumed as food. However,
since the compound exhibits significant cytotoxic activity, it
could be used as a lead in drug discovery for lung cancer.
Cardiovascular effects. When an extract of sweet potato
was examined for its relaxant activity on isolated rat vas-
cular aortic preparations, it showed 97% relaxation activity
for endothelium-intact aortic ring preparations but only 35%
in the mesenteric vascular bed. It showed good cardiovas-
cular effect and its vasorelaxation mechanism of action was
similar to that of the pharmacological agent acetylcholine.
84
Immune system effects. Sweet potato fiber may be use-
ful in combination with other therapeutic agents for skin
wound therapy. The healing effect of sweet potato fiber was
evaluated for burns and decubital wounds in rats over 19
days. Outcome measures included reduction in size and
differences in wound severity. Rats treated with the sweet
potato fiber covering had decreased wound areas.
85
In a mouse model, purified sweet potato polysaccharide
(PSPP) isolated from the roots acted as a biological response
modifier. In a dose-dependent manner, mice treated with
PSPP (50, 150, and 250 mg/kg body weight for 7 days) had
increased phagocytic function, hemolytic activity, and se-
rum immunoglobulin (IgG) concentration.
86
Anti-ulcer activity. The anti-ulcer activity of the tubers
of sweet potato was studied in cold stress and aspirin-
induced gastric ulcers in Wistar rats. Methanolic extracts of
I. batatas tubers were evaluated in cold stress and aspirin-
induced gastric ulcer models using cimetidine and ome-
prazole respectively as standards for 7 days in the cold stress
model and for 1 day in the aspirin-induced gastric ulcer
model. Gastroprotective potential, status of the antioxidant
enzymes (superoxide dismutase, catalase, glutathione per-
oxidase and glutathione reductase), along with glutathione
and lipid peroxidation, were studied in both models. The
results showed that I. batatas tubers possessed gastro-
protective activity, as evidenced by its significant inhibition
of mean ulcer score and ulcer index, and a marked increase
in glutathione, superoxide dismutase, catalase, glutathione
peroxidase, and glutathione reductase levels, as well as re-
duction in lipid peroxidation in a dose dependent manner.
87
Safety evaluation
Sweet potatoes contain oxalic acid, a naturally-occurring
substance found in some vegetables which may crystallize
as oxalate stones in the urinary tract in some people.
88
Therefore, individuals with a known history of oxalate uri-
nary tract stones may be advised to avoid eating them.
89
Adequate intake of water is also advised to maintain normal
urine output in these individuals to minimize stone risk.
CONCLUSION
Sweet potato is an extremely versatile vegetable and is
wonderfully healthy for children and adults alike. It is a
healthy alternative to other potatoes. They are not only
sweet but also good for cardiovascular health, longevity,
prevention of diabetes, and reduce the risk of cancer.
ACKNOWLEDGMENT
We are grateful to The Department of Biotechnology,
Government of India, New Delhi, for their financial support.
AUTHOR DISCLOSURE STATEMENT
The authors declare that no competing financial interests
exist.
REFERENCES
1. Purseglove JW: Tropical crops: Dicotyledons. Vol. 1. Longman,
London, 1972, pp. 82–91.
2. Woolfe JA: Sweet Potato–Past and Present. In: Sweet Potato: An
Untapped Food Resource, Cambridge University Press, Cam-
bridge, 1992, pp. 15–40.
3. Abel C, Busia K: An exploratory ethno botanical study of the
practice of herbal medicine by the Akan peoples of Ghana. Altern
Med Rev 2005;10:112–122.
4. Pochapski MT, Fosquiera EC, Esmerino LA, Santos EB, Farago
PV, Santos FA, et al.: Phytochemical screening, antioxidant, and
antimicrobial activities of the crude leaves’ extract from Ipomoea
batatas (L.) Lam. Pharmacogn Mag 2011;7:165–170.
5. Ludvik B, Neuffer B, Pacini G: Efficacy of Ipomoea batatas
(Caiapo) on diabetes control in type 2 diabetic subjects treated
with diet. Diabetes Care 2004;27:436–440.
6. Emmanuel N: Ethno medicines used for treatment of prostatic
disease in Foumban, Cameroon. Afr J Pharm Pharmacol 2010;
4:793–805.
738 MOHANRAJ AND SIVASANKAR
7. Namsa ND, Mandal M, Tangjang S, Mandal SC: Ethnobotany of
the Monpa ethnic group at Arunachal Pradesh, India. J Ethnobiol
Ethnomed 2011;7:31–39.
8. Zhao G, Kan J, Li Z, Chen Z: Characterization and im-
munostimulatory activity of an (1/6)-a-D-glucan from the
root of Ipomoea batatas.Int Immunopharmacol 2005;5:1436–
1445.
9. Bovell-Benjamin AC: Sweet Potato: A review of its past, present,
and future role in human nutrition. Adv Food Nutr Res 2007;52:
1–59.
10. Yen DE: The Sweet Potato and Oceania. Bishop Mus. Bull,
Honolulu, 1974, pp. 236–389.
11. Yen DE: Sweet potato in historical perspective. In: Sweet Potato.
Proceedings of the 1
st
International Symposium. (Villareal RL,
Griggs TD, ed.) Asian Vegetable Research and Development
Center, Taiwan, 1982, pp. 17–30.
12. Tarumoto I: Sweet Potato breeding in Japan: Its past, present and
future. In: Improvement of Sweet Potato (Ipomoea batatas) in
Asia, 1989, pp. 137–146.
13. FAO: FAO Production Yearbook, Rome, 1984.
14. Horton DE: World patterns and trends in sweet potato produc-
tion. Trop Agric 1988;65:268–270.
15. Huaman Z: Systematic botany and morphology of the sweet
potato plant. Lima, Peru: International Potato Center (CIP),
1992, pp. 5–11.
16. Loebenstein G, Thottappilly G: The Sweet Potato. Springer
Verlag, 2009, pp. 391–425.
17. Bouwkamp JC: Introduction part – 1. In: Sweet potato products:
a natural resource for the tropics, (Bouwkamp JC ed.) CRC
press, Boca Raton, Florida, 1985, pp. 3–7.
18. Kays SJ: Formulated Sweet potato products. In: Sweet potato
products a natural resource for tropics (Bouwkamp JC, ed.).
CRC Press, Boca Raton, Florida, 1985, pp. 205–218.
19. Lin SSM, Peet CC, Chen DM, Lo HF: Sweet potato production
and utilization in Asia and the Pacific. In: Sweet potato products:
a natural resource for the tropics (Bouwkamp JC, ed.). CRC
Press, Boca Raton, Florida, 1985, pp. 139–148.
20. Sakamoto S, Bouwkamp JC: Industrial products from sweet
potatoes. In: Sweet Potato Products: A Natural Resource for the
Tropics (Bouwkamp JC, ed.), CRC Press, Boca Raton, Florida,
1985, pp. 219–234.
21. Food and Nutrition Board (FNB): Recommended Dietary Al-
lowances — 1980. Nutrition Reviews, 1980;38:290–294
22. Watt BK, Merrill AL: Composition of foods: raw, processed,
prepared. In: Agriculture Handbook No. 8, U.S. Government
Printing Office, Washington D.C, 1975.
23. Anon.: Sweet Potato Quality. In: U.S.D.A. Southern Cooperative
Series Bulletin No. 249, Russell Research Centre, Athens,
Georgia, 1980
24. Ishida H, Suzuno H, Sugiyama N, Innami S, Tadokoro T, Mae-
kawa A: Nutritive evaluation on chemical components of leaves,
stalks, and stems of sweet potatoes (Ipomoea batatas Poir). Food
Chem 2000;68:359–367.
25. U.S.D.A. National Nutrient Database for Standard Reference,
Release 26. http://ndb.nal.usda.gov/ndb/foods/show/3254?fg =
&format =&offset =&sort =(accessed January 2013).
26. You WC, Blot WJ, Chang YS, Ershow AG, Yang ZT, An Q, et
al.: Diet and high risk of stomach cancer in Shandong, China.
Cancer Res 1988;48:3518–3523.
27. Huang DJ, Lin CD, Chen HJ, Lin YH: Antioxidant and anti-
proliferative activities of sweet potato (Ipomoea batatas [L.] Lam
‘‘Tainong 57’’) constituents. Bot Bull Acad Sin 2004;45:179–186.
28. Cereda MP, Franco CML, Daiuto ER, Demiate JM, Carvalho
LJCB, Leonel M, et al.: Propriedades gerais do amido, Fundac¸a
˜o
Cargill, Campinas, Brasil, 2001, pp. 21.
29. Antia BS, Akpan EJ, Okon PA, Umoren IU: Nutritive and anti-
nutritive evaluation of sweet potatoes (Ipomoea batatas) Leaves.
Pak J Nutr 2006;5:166–168.
30. Chandrika UG, Basnayake BMLB, Athukorala I, Colombagama
PWNM, Goonetilleke A: Carotenoid content and in vitro
bioaccessibility of lutein in some leafy vegetables popular in Sri
Lanka. J Nutr Sci Vitaminol (Tokyo) 2010;56:203–207.
31. Trumbo RP, Ellwood KC: Lutein and zeaxanthin intakes and
risk of age-related macular degeneration and cataracts: an eval-
uation using the Food and Drug Administration’s evidence-based
review system for health claims. Am J Clin Nutr 2006;84:
971–974.
32. Islam S: Sweet potato (Ipomoea batatas L.) Leaf: Its potential
effect on human health and nutrition. J Food Sci 2006;71:R13–
R21.
33. How Stuff Works: The Phytochemical Collection. http://health
.howstuffworks.com/framed.htm?parent =phytochemical.htm&
url =http://micro.magnet.fsu.edu/micro/gallery/phytochemicals/
phytochemical.html (accesses June 2013)
34. Taira J, Taira K, Ohmine W, Nagata J: Mineral determination
and anti-LDL oxidation activity of sweet potato (Ipomoea ba-
tatas L.) leaves. J Food Comp Anal 2013;29:117–125.
35. Johnson M, Pace RD: Sweet Potato leaves: properties and syn-
ergistic interactions that promote health and prevent disease.
Nutr Rev 2010;68:604–615.
36. Jung JK, Lee SU, Kozukue N, Levin CE, Friedman M: Dis-
tribution of phenolic compounds and antioxidative activities in
parts of sweet potato (Ipomoea batata L.) plants and in home
processed roots. J Food Comp Anal 2011;24:29–37.
37. Meira M, Pereira da Silva E, David JM, David JP: Review of the
genus Ipomoea: traditional uses, chemistry and biological ac-
tivities. Rev Bras Farmacogn 2012;22:682–713.
38. Mahmood N, Moore PS, Tommasi ND, Simone FD, Colman S,
Hay AJ, et al.: Inhibition of HIV infection by caffeoylquinic acid
derivatives. Antiviral Chem Chemother 1993;4:235–240.
39. Okudaira R, Kyanbu H, Ichiba T, Toyokawa T: Ipomoea extracts
with disaccharidase-inhibiting activities. Jpn Kokai Tokkyo Koho
JP 2005;5:213–221.
40. Islam S, Yoshimoto M, Ishiguro K, Yamakawa O: Bioactive
compounds in Ipomoea batatas leaves. ISHS Acta Hortic 2003;
2:693–699.
41. Yoshimoto M, Yahara S, Okuno S, Islam MS, Ishiguro K, Ya-
makawa O: Antimutagenicity of mono-, di-, and tricaffeoylquinic
acid derivatives isolated from sweetpotato (Ipomoea batatas L.)
leaf. Biosci Biotechnol Biochem 2002;66:2336–2341.
42. Zheng W, Clifford MN: Profiling the chlorogenic acids of sweet
potato (Ipomoea batatas) from China. Food Chem 2008;106:
147–152.
43. Dini I, Tenore GC, Dini A: New polyphenol derivative in Ipo-
moea batatas tubers and its antioxidant activity. J Agric Food
Chem 2006;54:8733–8737.
44. Basnet P, Matsushige K, Hase K, Kadota S, Namba T: Four
di-O-caffeoyl quinic acid derivatives from propolis potent
SWEET POTATO AS MEDICINAL FOOD 739
hepatoprotective activity in experimental liver injury models.
Biol Pharm Bull 1996;19:1479–1484.
45. Minamikawa T, Akazawa T, Uritani I: Isolation of esculetin from
sweet potato roots with black rot. Nature 1962;195:726.
46. Cambie RC, Ferguson LR: Potential functional foods in the
traditional Maori diet. Mutat Res 2003;523–524:109–117.
47. Kang SY, Sung SH, Park JH, Kim YC: Hepatoprotective activity
of scopoletin, a constituent of Solanum lyratum. Arch Pharm Res
1998;21:718–722.
48. Shaw CY, Chen CH, Hsu CC, Chen CC, Tsai YC: Antioxidant
properties of scopoletin isolated from Sinomonium acutum.
Phytother Res 2003;17:823–825.
49. Oliveira EJ, Romero MA, Silva MS, Silva BA, Medeiros IA:
Intracellular calcium mobilization as a target for the spasmolytic
action of scopoletin. Planta Med 2001;67:605–608.
50. Lee JH, Lee KT, Yang JH, Baek NI, Kim DK: Acet-
ylcholinesterase inhibitors from the twigs of Vaccinium oldhami
Miquel. Arch Pharm Res 2004;27:53–56.
51. Liu XL, Zhang L, Fu XL, Chen K, Qian BC: Effect of scopoletin
on PC3 cell proliferation and apoptosis. Acta Pharmacol Sin
2001;22:929–933.
52. Lima OOA, Braz-Filho R: Dibenzylbutyrolactone lignans and
coumarins from Ipomoea cairica.J Braz Chem Soc 1997;8:
235–238.
53. Guan Y, Wu T, Lin M, Lin M, Ye J: Determination of pharma-
cologically active ingredients in sweet potato (Ipomoea batatas)
by capillary electrophoresis with electrochemical detection. J
Agric Food Chem 2006;54:24–28.
54. Luo JG, Kong LY: Study on flavonoids from leaf of Ipomoea
batatas.Zhongguo Zhong Yao Za Zhi 2005;30:516–518.
55. Islam MS, Yoshimoto M, Terahara N, Yamakawa O: Antho-
cyanin composition in sweetpotato (Ipomoea batatas L.) leaves.
Biosci Biotechnol Biochem 2002;66:2483–2486.
56. Terahara N, Shimizu T, Kato Y, Nakamura M, Maitani T, Ya-
maguchi M, et al.: Six diacylated anthocyanins from the storage
roots of purple sweet potato, Ipomoea batatas.Biosci Biotechnol
Biochem 1999;63:1420–1424.
57. Yang C, Tsai T: Four acylated anthocyanins from red skin sweet
potatoes (Ipomoea batatas). Shipin Kexue (Tapei) 1999;26:
182–192.
58. Lee L, Cheng E, Rhim J, Ko B, Choi S: Isolation and identifi-
cation of anthocyanins from purple sweet potatoes. J Food Sci
Nutr 1997;2:83–88.
59. Goda Y, Shimizu T, Kato Y, Nakamura M, Maitani T,
Yamada T, Terahara N, Yamaguchi M: Two acylated anthocy-
anins from purple sweet potato. Phytochemistry 1997;44:
183–186.
60. Odake K, Terahara N, Saito N, Toki K, Honda T: Chemical
structures of two anthocyanins from purple sweet potato, Ipo-
moea batatas.Phytochemistry 1992;31:2127–2130.
61. Tsukui A, Kuwano K, Mitamura T: Anthocyanin pigment iso-
lated from purple root of sweet potato. Kaseigaku Zasshi
1983;34:153–159.
62. Son K, Severson RF, Arrendale RF, Kays SJ: Isolation and
characterization of pentacyclic triterpene ovipositional stimulant
for the sweet potato weevil from Ipomoea batatas (L.) Lam. J
Agric Food Chem 1990;38:134–137.
63. Kilham C: Tamanu oil: a tropical topical remedy. HerbalGram
2004;63:26–31.
64. Tan G, Xu P, Dai Z, Tang G: Studies on the chemical compo-
nents of Ipomoea batatas Lam. Tianran Chanwu Yanjiu Yu Haifa
1995;7:44–46.
65. Krogh R, Krogh R, Berti C, Madeira AO, Souza MM, Cechinel-
Filho V, et al.: Isolation and identification of compounds with
antinociceptive action from Ipomoea pes-caprae (L.) Die Phar-
mazie 1999;54:464–466.
66. Boyd MR, Burka LT, Harris TM, Wilson BJ: Lung-toxic fur-
anoterpenoids produced by sweet potatoes (Ipomoea batatas)
following microbial infection. Biochem Biophys Acta 1974;337:
184–195.
67. Wilson BJ, Boyd MR, Harris TM, Yang DT: A lung oedema
factor from moldy sweet potatoes (Ipomoea batatas). Nature
1971;231:52–53.
68. Boyd MR, Wilson BJ: Isolation and characterization of 4-
Ipomeanol, a lung-toxic furanoterpenoid produced by sweet
potatoes (Ipomoea batatas). J Agric Food Chem 1972;20:
428–430.
69. Duke JA, Wain KK: Medicinal Plants of the World. Computer
index with more than 85,000 entries. 3 vols. Agriculture Re-
search Service, Beltsville, Maryland, 1981.
70. Hermes D, Dudek DN, Maria M, Horta LP, Lima EN, Fatima A,
et al.: In vivo wound healing and antiulcer properties of white
sweet potato (Ipomoea batatas). J Adv Res 2013;4:411–415.
71. Rengarajan S, Rani M, Kumaresapillai N: Study of ulcer pro-
tective effect of Ipomea batatas (L.) dietary tuberous roots
(Sweet Potato). Iranian J Pharmacol Therap 2012;11:36–39.
72. Teow CC, Truong VD, McFeeters RF, Thompson RL, Pecota
KV, Yencho GC: Antioxidant activities, phenolic and b-carotene
contents of sweet potato genotypes with varying flesh colors.
Food Chem 2007;103:829–838.
73. Chang WH, Hu SP, Huang YF, Yeh TS, Liu JF: Effect of purple
sweet potato leaves consumption on exercise-induced oxidative
stress and IL-6 and HSP72 levels. J Appl Physiol (1985)
2010;109:1710–1715.
74. Rumbaoa RGO, Cornago DF, Geronimo IM: Phenolic content
and antioxidant capacity of Philippine sweet potato (Ipomoea
batatas) varieties. Food Chem 2009;113:1133–1138.
75. Oke JM, Oladosu B, Okunola MC: Sweet potato (Ipomoea ba-
tatas) tuber - potential oral antidiabetic agent. Afr J Biomed Res
1999;2:13–17.
76. Grotto, D: 101 Foods That Could Save Your Life. Bantam Bell,
New York, 2008.
77. Stanard S: Perspectives Online: Researchers reveal sweet potato
as weapon against diabetes. http://www.cals.ncsu.edu/agcomm/
magazine/winter07/diabetes.html (accessed April 2011)
78. Washio M, Mori M, Sakauchi F, Watanabe Y, Ozasa K, Hayashi K, et
al.: Risk Factors for kidney cancer in a Japanese population: findings
from the JACC Study. J Epidemiol 2005;15 Suppl 2:S203–S211.
79. Baer BR, Rettie AE, Henne KR: Bioactivation of 4-Ipomeanol by
CYP4B1: adduct characterization and evidence for an enedial
intermediate. Chem Res Toxicol 2005;18:855–864.
80. Lakhanpal S, Donehower RC, Rowinsky EK: Phase II study of 4-
Ipomeanol, a naturally occurring alkylating furan, in patients
with advanced hepatocellular carcinoma. Invest New Drugs
2001;19:69–76.
81. Falzon M, McMahon JB, Schuller HM, Boyd MR: Metabolic
activation and cytotoxicity of 4-Ipomeanol in human non-small
cell lung cancer cell lines. Cancer Res 1986;46:3484–3489.
740 MOHANRAJ AND SIVASANKAR
82. Smiley-Jewell SM, Plopper CG: Proliferation during early
phases of bronchiolar repair in neonatal rabbits following lung
injury by 4-Ipomeanol. Toxicol Appl Pharmacol 2003;192:
69–77.
83. Hsu H, Rainov NG, Quinones A, Eling DJ, Sakamoto KM, Spear
MA: Combined radiation and cytochrome CYP4B1/4-Ipomeanol
gene therapy using the EGR1 promoter. Anticancer Res 2003;
23:2723–2728.
84. Runnie I, Salleh MN, Mohamed S, Head RJ, Abeywardena
MY: Vasorelaxation induced by common edible tropical plant
extracts in isolated rat aorta and mesenteric vascular bed.
J Ethnopharmacol 2004;92:311–316.
85. Suzuki T, Tada H, Sato E, Sagae Y: Application of sweet potato
fiber to skin wound in rat. Biol Pharm Bull 1996;19:977–983.
86. Zhao G, Kan J, Li Z, Chen Z: Characterization and im-
munostimulatory activity of an (1/6)-a-D-glucan from the root
of Ipomoea batatas.Int Immunopharmacol 2005;5:1436–1445.
87. Panda V, Sonkamble M: Anti-ulcer activity of Ipomoea batatas
tubers (sweet potato). Functional Foods in Health and Disease
2012;2:48–61.
88. Faboya O, Ikotun T, Fatoki OS: Production of oxalic acid by
some fungi infected tubers. Z Allg Mikrobiol 1983;23:621–624.
89. Noonan SC, Savage GP: Oxalate content of foods and its effect
on humans. Asia Pac J Clin Nutr 1999;8:64–74.
SWEET POTATO AS MEDICINAL FOOD 741
