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 Botany
Kamote is a spreading, prostrate, herbaceous, smooth or somewhat hairy vine. Stems or runners, sprawling several meters long, take root when
in contact with soil. Leaves are ovate to oblong-ovate, 6 to 14 centimeters long, somewhat entire, with alternate heart-shaped or palmately lobed leaves, pointed at the tip, and heart-shaped at the base.
Flowers are sympetalous like that of morning glory, 5 centimeters long, funnel-shaped, purple, self sterile, and rarely producing seeds. Stamens are 5, of different lengths attached to corolla (epipetalous)
with hairy filaments. Sepals are about 1 centimeter long and greenish with pointed lobes. Corolla is funnel shaped, 4 to 5 centimeters long, pink, purple, and whitish. The edible and sweet-tasting tuberous root is long and tapered with a
smooth skin of varying colors from red, purple, brown and white. The
flesh varies from white, orange, purple and yellow.
 Distribution
- A warm season crop extensively cultivated in the Philippines.
- Can be planted any time of the year.
- Easily propagated from stem cuttings.
- Introduced by the Spaniards from Mexico in the early colonial period.
- Cultivated in all warm countries.
Constituents
• Leaves have a high content of polyphenolics - anthocyanins and
phenolic acids, with at least 15 biologically active anthocyanins with
medicinal value. (1)
• Polyphenols have physiologic functions, radical scavenging activity,
antimutagenic, anticancer, antidiabetes and antibacterial activity in
vitro and vivo.
• Study isolated four compounds: citrusin C, caffeic acid, 3,4-di-O-caffeoylquinic acid and 1,2,3,4-tetrahydro-beta-carboline-3-carboylic acid.
• Nutrient and anti-nutrient study of leaves yielded: crude protein, 24.85%; crude fat, 4.90%; crude fibre, 7.20%; ash, 11.10%; carbohydrate, 51.95%; moisture contents, 82.21%; and calorific values, 351.30. Vitamin composition showed: vitamin A, 0.672 mg/100g; vitamin C, 15.20 mg/100g. Elemental analysis showed appreciable levels of zinc (0.08), potassium (4.05), sodium (4.23), manganese (4.64), calcium (28.44), magnesium (340.00) and iron (16.00). It showed low levels of toxicants. (See studies below) (29)
• Nutrient value of sweet potato per 100 g yields energy 360 kJ (86kcal), starch 12.7 g, sugars 4.2 g, dietary fiber 3.0 g, fat 01 g, protein 1.6 g, vitamin A equivalent 709 µg, thiamine (B1) 0.1 mg, riboflavin (B2) 0.1 mg, niacin (B3) 0.61 mg, pantpthenic acid (B4) 0.8 mg, pyridoxine (B60 0.2 mg, folate (B9) 11 µg, vitamin C 2.4 mg, vit E 0.26 mg, calcium 30.0 mg, iron 0.6 mg, magnesium 25.0 mg, phosphorus 47.0 mg, potassium 337 mg, sodium 55 mg, zinc 0.3 mg. (46)
Properties
• Considered antioxidant, antimutagenic, antibacterial, antidiabetic.
• Considered hemostatic, spleen invigorating.
• Studies have suggested
antioxidant, antidiabetic, wound healing, immunomodulatory, hypolipidemic, antiproliferative, hemostatic, antiulcer properties.
Parts utilized
Tops, leaves and edible roots.
Uses
Nutritional
- Leaves and roots are edible.
- Has a higher nutritional value than the common potato. It is an average calorie starch food, which provided 90 calories/100 g vs 70 calories/100g of other types of potatoes (Solanum tuberosum). (46)
- Good source of vitamins A, B and C, iron, calcium and phosphorus.
- High in complex carbohydrates and dietary fiber; deficient in protein.
- Leafy tops eaten as vegetables.
- A component of many traditional cuisines.
- A staple food crop in some countries.
Folkloric
- Tops, especially purplish ones, used for diabetes.
- Crushed leaves applied to boils and acne.
- Boiled roots used for diarrhea.
- In Southwest Nigeria, hot water infusion of the whole plant used in the management of diabetes mellitus.
Industrial
Starch and industrial alcohol production.
Others
• Dengue: Like gatas-gatas
(Euphorbia hirta), there have been anecdotal reports of the use of Ipomoea
batatas in dengue, with improvement in platelet counts being
attributed to decoctions of kamote tops.
Preparation: kamote tops are boiled in water for 5 minutes to extract
the juice
 Studies
• Diabetes:
Despite its "sweet" name, it
may be beneficial for diabetes as some studies suggest it may stabilize
blood sugars and lower insulin resistance. (•) Study showed the flavone
extracted from IB leaf could control blood sugar and modulate the metabolism
of glucose and blood lipid, and decrease outputs of lipid peroxidation
and scavenge the free radicals in non-insulin dependent diabetic rats. (•)
• Hematologic / Hemostatic: Hemostatic mixture
of ipomoea balatas leaves, methods of preparation and use thereof —
a Jinshuye styptic plant preparation, an invention made from the extracts
of leaf and stems of Ipomoea batatas has qi and spleen invigorating
effects, cooling the blood and stopping bleeding. Such a composition
has the potential of use for ITP (idiopathic thrombocytopenic purpura),
radiotherapy- and chemotherapy-induced thrombocytopenia. (8) Study evaluated the hemostatic activity of sweet potato leaf aqueous and ethanolic crude extracts primarily on platelet count, clotting time and prothrombin time on white rabbit model. Both extracts significantly increase (p<0.05) the platelet count and significantly decrease (p<0.05) the clotting time and prothrombin time. Results suggest interaction with both intrinsic and extrinsic pathways and suggest potential for the prevention of bleeding tendencies. (50)
• Root Crops as Antioxidant: A
2006 study of commonly consumed roots crops in the Philippines (Kamote,
Ipomoea batatas; ubi, purple yam, Dioscorea
alata; cassava, Manihot esculenta; taro or gabi, Colocasia esculenta;
carrot, Daucus carota; yacon (Smallanthus sonchifolius) showed them
to be rich sources of phenolic compounds with antioxidant activity,
highest in sweet potato, followed by taro, potato, purple yam and lowest
in the carrot.
• Antioxidant: Study results suggest the total phenolic content was positively correlated
with radical scavenging activities of the sweet potato leaves.
• Antioxidant / Anthocyanins:
Purple Sweet Potato anthocyanins have antioxidative activity in vivo
as well as in vitro.
• Diabetes / Anti-Diabetic and Lipid Effects / White Skinned Sweet Potato:
Results suggest the white skinned sweet
potato has antidiabetic activity and and improves glucose and lipid
metabolism by reducing insulin resistance. (2)
• Diabetes: Study to isolate the antidiabetic component
of white-skinned sweet potato suggested the active component to be an
acidic glycoprotein because it contained a protein and sugar and adsorbed
onto the QA column at pH 7.0.
• Caiapo:
Study confirmed the beneficial effects of
Caiapo (a neutraceutical) on plasma glucose with a decrease in Hb A1c,
as well as cholesterol levels, in type 2 diabetes patients. (10)
• Sweet potato root with antioxidant
activities in vitro / Mucilage: Mucilage might contribute its antioxidant
activities against both hydoxyl and peroxyl radicals. (4)
• Flavonoids:
Leaf extract study isolated five news compounds:
tiliroside, astragalin, rhamnocitrin, rhamnetin and kaempferol. (11)
• Chitinases:
Study identified new chitinolytic enzymes
in sweet potato leaves. Chitinases catalyze the hydrolysis of chitin,
the main structural component of fungal walls and arthropod integuments.
Studies suggest it has other functions and has been proposed to play
a role in the defense against pathogens. Chitinases are also useful
in the production of biomedical and biotech products; used in the production
of chitooligosaccharides, glucosamines and GlcNAc. Other applications
are found in mosquito control and pathogenic plant fungi control. (13)
• Antioxidant
/ Antiproliferative: Study demonstrated that the phytochemicals
in sweet potato may have significant antioxidant and anticancer activities.
The antioxidant activity was directly related to the total amount of
phenolics and flavonoids in the extracts. The additive roles of phytochemicals
may contribute to its ability in inhibiting tumor cell proliferation
in vitro. (14)
• Antidiabetic
/ Adiponectin / Natural Insulin Sensitizer: Study confirms the beneficial effects of Caiapo on glucose and HbA1c in T2DM. The improvement in insulin sensitivity was accompanied by increased levels of adiponectin and a decrease in fibrinogen. (15)
• Antiulcer: Study in cold stress and aspirin-induced gastric ulcers in Wistar rats showed Ipomoea batatas tubers possess gastroprotective activity as shown by inhibition of mean ulcer score and ulcer index and a marked increase in GSH, SOD, CAT, GPx, and GR levels and reduction in lipid peroxidation in a dose-dependent manner. (17) An ethanolic extract of Ipomoea batatas showed antiulcer activity as evidenced by significant inhibitory effects on pylorus ligated and cold restraint stress induced ulcer. (28)
• Antiproliferative / Antioxidant: Study examined the antioxidant and antiproliferative activities of different extracts of sweet potato. In the DPPH staining, the ethanol extract of vein had the highest radical-scavenging activity. Among the extracts the ethanol extract showed the highest amount of total phenolic and flavonoid compounds. The water extract of the vein showed the highest antiproliferative activity with an EC50 of 449.6 ± 27.73 ug/mL. (18)
• Comparative Antioxidant Properties / Natural Yellow Dye: Study showed the carotenoids extraction process retained most of the antioxidant capacity from the leaves. It is also a potential source of natural yellow dye with antioxidant property that can be beneficial to human health, as an alternative to the artificial coloring dye currently used in the market. (19)
• Anthocyanins / Antitumor Effect: Study showed Ipomoea batatas Poir Cv anthocyanins could have an inhibitory effect on transplantation tumor of mice, with no toxicity and no mutation. (21)
• Wound Healing / Peels: In an incision wound model, high tensile strength of the wounded skin was noted in animals treated with peel extract gels and the peel bandage when compared to controls. There was also significant wound closure by the 4th day, a significant increase in hydroxyproline and ascorbic acid and decrease in malondialdehyde content. The wound healing activity was attributed to possible underlying antioxidant mechanism. (22)
• Hypoglycemic Effect: Study in STZ-induced hyperglycemic rats fed oral doses of extracts showed significant dose-related reductions in FBG. Phytochemical analysis of the extract showed alkaloids, flavonoids, tannins, saponins, anthraquinones and reducing sugars. (23) In a study on hypoglycemic effects of cooked and uncooked methanol and aqueous extracts of sweet potato tuber, results showed the active principles responsible for the antihyperglycemic effect are concentrated in the methanolic extract and aqueous suspension of the uncooked tuber. (41)
• Thyroid-Gonadal Axis Effect: Study investigated the effect of a leaf extract on the thyroid gonadal axis of male rats. Results showed follicles hypertrophy and hyperplasia and reduction of colloid in the follicular lumen. Testes morphology showed oligospermia, asthenospermia and abnormal sperm morphology. Results suggest a male contraceptive property of the plant extract, the mechanism possibly as both a direct effect on the gonads of indirectly via the hypothalamo-hypophyseal axis. (25)
• Mode of Action in Type 2 Diabetes: Study describes the underlying mechanism responsible for improvement in metabolic control following administration of Caiapo in type 2 diabetic patients. Results suggest that in short term use of Caiapo, improved metabolic control of T2DM was achieved by decreasing insulin resistance without affecting body weight, glucose effectiveness or insulin dynamics. (26)
• Reduction of Food Intake, FBS, and Body Weight: Study evaluated the effect of aqueous extract of Ipomoea batatas on food intake, fasting blood glucose and body weight in male wistar rats. Results showed reduction in food intake probably by increasing satiety and reduction in weight gain by using up the body's reserve of fat as a result of low blood glucose. (27)
• Nutritive and Anti-Nutritive Evaluation: Study evaluated levels of some nutrients and antinutrients of sweet potato leaves. Results showed leaves contain an appreciable amount of proteins, minerals, fat, fibre, carbohydrate, caloric values (energy) and low levels of toxicants except for oxalate whose value is reduced by cooking. Results suggest leaves can contribute significantly to nutrient requirements of man. (See constituents above) (29)
• Antioxidant Activity / Phenolic and Flavonoid Contents / Leaves: Study evaluating six leafy varieties of Ipomoea batatas showed the presence of total flavonoids, total phenolics, reducing activity, and the ability to scavenge free radicals, and suggest leaves can be used as a potential source of natural antioxidants. (30)
• In Vitro Cytotoxic and Antioxidant Activity: An ethanolic extract of Ipomoea batatas showed potent cytotoxic activity in trypan blue dye exclusion method using DLA cell lines and exhibited a dose dependent decrease in cell count. The extract exhibited potent antioxidant activity by DPPH free radical assay. (31)
• Effects on Hematological and Biochemical Parameters: Study of leaf aqueous extract of I. batatas showed no significant changes in hematological parameters. There were not significant changes in activities of serum enzymes. The pentobarbitone sleeping time showed significant ( p < 0.001) increase in the mean sleeping time when the group that received the extract was compared with the control. (32)
• White-Skinned Sweet Potato / Hypoglycemic Effect / Mechanisms: Study investigated the mechanism of white-skinned sweet potato (Ipomoea batatas) on reducing blood glucose in STZ-induced diabetic rats. Results showed hypoglycemic activity by inducing pancreatic beta cells regeneration and increasing insulin expression. (33)
• Anti-Hyperglycemic Effect of Diacylated Anthocyanin: Study evaluated a postprandial glucose suppression effect of diacylated anthocyanin with α-glucosidase (AGH) inhibitory activity in Sprague−Dawley rats. Results showed the anti-hyperglycemic effect of the anthocyanin was achieved by maltase inhibition, not by sucrase or glucose transport inhibition at the intestinal membrane. (34)
• Effect on Haematological Parameters / Leaves: Study showed sweet potato leaves (Ipomoea batatas) significantly increased PCV, WBC, and platelet count, while the differential white cell count remained the same. The results could be a direct effect on haemopoietic tissues. (35)
• Wound Healing / Antiulcerogenic / Tuber Flour: Study evaluated the wound healing and anti-ulcerogenic potential of tuber flour of Ipomoea batatas in vivo in animal model. Tuber flour potentially prevented ethanol-induced gastric ulceration by suppressing edema formation and partly protecting gastric mucosa wrinkles. Ointment based formulation effectively triggered the healing of cutaneous wound with increased number of cells undergoing metaphase and tissue re-epithelialization. Crude extracts also exhibited potential as free radical scavengers. (36)
• Starch Binder Healing for Meat Products: Study showed sweet potato starch could be used up to 4% inclusion in meat products, to minimized formulation costs and consumer concerns about excessive used of chemical ingredients in meat products. (37)
• Effect on Malondialdehyde and Nitrous Oxide Levels in Smokers: Cigarette smoke is an exogenous source of free radicals containing more than 400 chemical compounds triggering the formation of free radicals associated with disease and the aging process. Study evaluated the effect of I. batatas as a source of antioxidants that decrease malondialdehyde (MDA) and increase nitrous oxide (NO) in plasma of moderate smokers. There was a decrease in MDA and increase in NOx plasma levels in the treatment groups. Study suggests IB syrup contains 8 mg/mL anthocyanins, which probably play a role in reducing free radicals and provide benefits in reducing risk of disease and slowing the aging process. (38)
• Reduced Food Intake: Study investigated the effect of an aqueous extract of sweet potato on food intake in male Wistar rats. Results showed consumption of IB extract caused a reduction in food intake probably by reducing appetite and increasing satiety. (39)
• Antisickling Activity / Leaves: Study evaluated the antisickling activity of Ipomoea batatas leaves through an in vivo bioassay. Results showed an antisickling effect, partly attributed to anthocyanins. (40)
• Attenuation of Amyloid ß Peptide-Induced Neurotoxicity: Study evaluated the protective effects of 17 Korean native plants against amyloid ß peptide (Aß)-induced oxidative stress in ICR mice. Ipomoea batatas showed the highest protective effect against oxidative stress. In ICR mice with Aß-induced neuronal deficits, Ipomoea batatas significantly reversed Aß-induced neurotoxicity, reduced the level of lipid peroxidation, and increased catalase activities in biochemical studies of mice brain tissue. (42)
• Increased Neutrophil Phagocytic Function / Cell-Mediated Immune Effect / Roots: Study of a methanol extract of roots showed stimulation of cell mediated immune system by increasing neutrophil phagocytic action. (43)
• Anti-Neuroinflammatory / Antioxidant: Study evaluated the protective effects of purple sweet potato extract in stimulated BV-2 microglial cells and its anti-oxidant properties. Results showed IBE attenuated neuroinflammatory responses in LPS-activated BV-2 microglia by inhibiting excessive production of pro-inflammatory mediators such as NO, iNOS, COX-2 and TNF-α. The effect can be related to its strong antioxidant properties. (44)
ª No Effect of Leaves Extract on Induced Traumatic Oral Ulcers / Leaves: Study showed Ipomoea batatas leaves extract had no significant effect on percentage healing of tramatic ulcer in oral mucosa of male rat model. (46)
• Anti-Lithiatic Potential / Leaves and Tuberous Roots: Study evaluate the in vitro anti-lithiatic effect of ethanolic extract of Ipomoea batats leaves and tuberous roots. The leaves and roots showed significant (p<0.01) capability to dissolve calcium oxalate The extracts also significantly (p<0.01) inhibited both nucleation and aggregation of calcium oxalate crystals in a concentration-dependent manner. (47)
• Anti-Inflammatory / Anticancer / Purple-Fleshed Sweet Potato: Purple-fleshed sweet potato (PFSP) has been known to possess high amount of anthocyanins which contribute to its antioxidant property. In this study, extracts of PFSP exhibited anti-inflammatory activities by suppressing production of NO and pro-inflammatory cytokines. Anticancer activities were displayed by ability to inhibit the growth of cancer cell lines, such as MCF-7 (breast), SNU-1 (gastric) and WiDr (colon adenocarcinoma) in concentration- and time-dependent manner. The SP extracts could induce apoptosis in MCF-7 and SNU-1 cancer cells through intrinsic and extrinsic pathways. (48)
• Platelet Raising Effects / Leaves: Studies have revealed platelet increasing effect of Sweet Potato leaf extract in experimental animals. Study investigated the effect of an aqueous extract of Ipomoea batatas leaf on platelet count. Results showed a dose dependent platelet raising effect, and may be of benefit in the management of thrombocytopenia. Antioxidant activity of tannins component of the extract mignt protect stem cells and platelets from free radical induced injury. (49)
Availability
- Wild-crafted.
- Common market produce.
- Caiapo, in the cybermarkets, an extract of
white sweet potatoes.
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