Ubi-ubihan is a climbing or twining, dioecious, smooth, unarmed vine reaching a length of several meters. Tubers are rounded, not larger than a man's fist. Stems are terete, bearing numerous little tubers. Leaves are simple, ovate, 7 to 14 centimeters long, with a broad and prominently heart-shaped base, broad and rounded sinus, rounded lobes, and 7- to 9-nerved. Spikes are slender, panicled, numerous, 8 to 10 centimeters long, and rather densely many-flowered. Flowers are about 3 millimeters long. Capsules are longer than broad. Seeds are winged at the base only.
- In thickets at low and medium altitudes.
- Sometimes cultivated as an oddity for its tubers.
- Also occurs in India to China and Malaya.
- Tubers reported to contain a poisonous glucoside.
- Tuber extract is rich in flavonoid, phenolics, reducing sugars, starch, diosgenin, ascorbic acid, and citric acid.
- Study for chemical constituents of tubers yielded14 compounds identified as stigmasterol (1), mono-arachidin (2), 1,7-bis-(4-hydroxyphenyl)-1E,4E,6E-heptatrien-3-one (3), behenic acid (4), demethyl batatasin IV (5), 2,3'-di-hydroxy-4',5'-dimethoxybibenzyl (6), diosbulbin B (7), diosbulbin D (8), docosyl ferulate (9), 7-bis-(4-hydroxyphenyl) -4E, 6E-heptadien-3-one (10), 5,3,4-trihydroxy-3,7-dimethoxyflavone (11), tristin(12), protocatechuic acid (13), adenosine (14). (9)
- Study yielded three norclerodane diterpenoids: diosbulbins K-M, and one enoglycoside, diosbulbinoside G, with four norclerodane diterpenoids, disobulbins B, E, F and G from the rhizomes.
- Phytochemical analysis of tubers yielded steroids, flavonoids, cardiac glycosides, saponins, and reducing sugars. (see study below) (22)
- An ethyl acetate soluble fraction of 75% ethanol extract yielded flavonol aglycones, namely kaempferol-3, 5-dimethyl ether, caryatin, and catechin. It also yielded flavonol glycosides, namely quercetin-3-O-galactopyranoside, myricetin-3-O-galactopyranoside, and myrcetin-3-O-glucopyranoside. (Kuroyanagi et al, 2002).
- Fingerprinting of DBT extracts by UHPLC yielded ten common peaks accounting for 80^ of overall peak areas, and identified as: epigallocatechin (1), kaempferol-3-O-β-D-galactoside (2), catechin dimers (3), catechin (4), catechin dimers (5), epicatechin (6), 9,10-dihydro-2,3,5,7-phenanthrenetetraol (7), caryatin (8), diosbulbin B (DIOB) (9), 8-epidiosbulbin E acetate (EEA) (10). (see study below) (27)
- In a comparative analysis of phytochemical and nutritional compositions of four species of Dioscorea, D. bulbifera had the highest levels of alkaloid (0.64 ± 0.01 mg/100g), tannin (0.54 mg/100g), saponin (0.58 mg/100g), oxalate (0.75 ± 0.01 mg/100g), ash (5.49 ± 0.04%), crude fiber (3.45 ± 0.01%), crude protein (5.86%), vitamin B1 (0.042 mg/100g), vitamin B3 (0.037 mg/100g), and vitamin C (0.63 ± 0.02 mg/100g), calcium (378.52 ± 0.10 mg/100g), magnesium (128.73 ± 0.04 mg/100g), sodium (87.80 ± 0.10 mg/100g), iron (3.14 ± 0.02 mg/100g) and zinc (2.79 ± 0.01 mg/100g). (28)
- Study of rhizomes of D. bulbifera isolated one new bibenzyl (7), one new diarylheptanone, diobulbinone A (18), along with 16 known compounds, (1-6 and 8-17) . (see study below) (33)
- Phytochemical studies have yielded alkaloids, flavonoids, glycosides, saponin, tannin, protein, carbohydrates, phytosteroids. (36)
- In the wild, tubers, when fresh, are bitter.
- Cultivated tubers are less or non-bitter.
- Tubers considered tonic, expectorant, aphrodisiac and anthelmintic.
- Studies have suggest antioxidant, anticancer, wound healing, antihyperglycemic, antidyslipidemic, cardioprotective, anthelmintic, analgesic, anti-inflammatory properties.
Tubers, roots, twigs, shoots.
- Tubers are reported edible, with a flavor similar to potato.
- Considered inedible by some because of bitterness and fibrous coarseness.
- Wild fresh tubers are bitter; cultivated tubers are less or non-bitter.
- Some report the tubers are poisonous when raw.
- In India, raw tuber is eaten to enhance appetite. (21)
- Tubers taken internally as remedy for dysentery and syphilis.
- Tubers used as resolvent for boils and as diuretic.
- Powdered tubers used as application for sores, piles and to stop diarrhea.
- In India, a folk remedy used to cure wounds, leucoderma and boils. Also, used as tonic, expectorant in asthma, as aphrodisiac and anthelmintic.
- In Chinese medicine, used to treat diseases of the lungs, kidney, spleen and many types of diarrhea.
- In Bangladesh, used for treatment of leprosy and tumors. In Zimbabwe, infusions applied to cuts and sores. In Cameroon and Madagascar, used for treatment of abscesses and wound infection. In Brazil and Java, used as remedy for diarrhea and dysentery. In China, used for dog bites, snake bits and food poisoning; also used for sore throat and goiter. (20)
- Local people of Similipal Biosphere Reserve in India use tubers to relieve intestinal colic, dysmenorrhea, spasmodic asthma, inflammation, menopausal problem, labor pain, and prevention of early miscarriage. Paste used for skin infections. Bulbils used to relieve sore throat. Tubers used to for boils and dysentery; powdered tuber mixed with butter used for diarrhea. Tender shoots and twigs, crushed and rubbed on wet hair to remove dandruff. Root paste with cow milk used to treat cough and asthma. Tuber powder used to kill hair lice. Tuber powder taken for 5-6 days once daily after menses as contraceptive. ( 21)
- Phytochemical screening of ethanol and aqueous extracts of leaves yielded
alkaloids, glycosides, saponins, tannins, flavonoids, reducing compounds, and polyphenols, with absence of phlobatannins, anthraquinones, and hydroxymethyl anthraquinones. (40)
• Anticancer: Anticancer screen carried out in vivo with HepA in mice showed active anticancer compounds from the hydrophobic constituents of D. bulbifera. The anticancer effects were related to direct toxicity on tumor cells. (2)
• Liver Toxicity Studies: Study to evaluate the liver-toxic fraction in Rhigoma of Dioscorea bulbifera is rats showed significant liver toxicity. The chloroform extract was the liver toxic fraction. (3)
• Antioxidant: Study evaluated the antioxidant activity of D. bulbifera. showed impressive levels of enzymatic (GPx, CAT, SOD, G6PD, GST) and commendable stores of non-enzymatic antioxidants (reduced GSH, vitamins C and E). (3)
• Antitumor Promoting / Constituents: Study of rhizome extracts yielded 28 compounds. some showed different inhibitory activities against tumor promotion of JB6 (CI22 and CI41) cells. The EtOAc and n-BuOH fractions were found to be potent anti-tumor promoters. (4)
• Hepatotoxicity: Study in mice showed the EtOAc fraction contains the main toxic ingredients of D. bulbifera rhizome, and the mechanism of hepatotoxicity may be due to liver oxidative stress injury in mice. (5)
• Wound Healing: Study of tuber extract revealed significant wound healing activity, high rate of wound contraction and decrease in the period for epithelization. (6)
• Antihyperglycemic / Antidyslipidemic: Study of aqueous extract of tubers in glucose-primed and STZ-treated Wistar rats showed significant antihyperglycemic and antidyslipidemic effects. (8) Study evaluated the biochemical effects of hydromethanolic extract of Dioscorea bulbifera on biochemical parameters (serum glucose, proteins, lipid profile and liver enzymes) sing Wistar rats. Results showed reduction in serum glucose, lipid profile, and weight of animals. Findings suggest potent hypoglycemic and hypolipidemic activity. (25)
• Myocardial Protective Effect: Study of hydroalcoholic extract showed D. bulbifera could ameliorate myocardial ischemia and reperfusion injury by improving ventricular function and inhibition of cardiomyocyte necrosis and apoptosis. (11)
• Anthelmintic: Study of D. bulbifera extract showed significant anthelmintic activity, especially against Eicinia fetida, Ascardia galli and Raillietina spiralis. Results provide a rationale for its traditional use as an anthelmintic. (12)
• Analgesic / Anti-Inflammatory: Study of aqueous and methanol extracts from the dry bulbils of D. bulbifera L. var sativa showed a dose-dependent inhibition of pain and inflammation. The exhibited potent analgesic and anti-inflammatory effects may result from inhibition of inflammatory mediators such as histamine, serotonin and prostaglandins. (13)
• Hepatotoxicity: Study investigated the hepatotoxicity induced by D. bulbifera in mice. Results showed the EtOAc fraction (EF) contains the main toxic ingredients of D. bulbifera rhizome, and the mechanism of hepatotoxicity induced by it may be due to liver oxidative stress injury in mice. (16)
• Antidiabetic Activity: A preliminary study has shown antihyperglycemic and antihyperlipidemic activity of D. bulbifera on Wistar rats. Study explored D. bulbifera as potential glycosidase inhibitors. D bulbifera showed significant inhibition with porcine pancreatic amylase and crude murine glucosidase as well as pure a-glucosidase. It suggests a potential as an effective herbal formulation in combinational therapy. (17) Study evaluated the antidiabetic effect of an ethanolic extract of D. bulbifera tuber on alloxan induced diabetic rats. The extract significantly reduced blood glucose and compared favorably with standard drug metformin. (38)
• Nanoparticles using D. bulbifera / Synergism with Antimicrobial Agents: Study is the first report on the synthesis of silver nanoparticles using D. bulbifera tuber extract, with an estimation of its synergistic potential for enhancement of the antibacterial activity of broad spectrum antimicrobial agents. (18)
/ Tubers: Study evaluated extracts of D. bulbifera for antimicrobial efficiency against MDR (multidrug resistant) clinical isolates. Results showed excelled activity against MDR microbial cultures tested. Aqueous and chloroforms extracts showed potent inhibitory activities against majority of isolates such as E. coli, Acinetobacter sp., S. paratyphi, K. pneumonia and Candida albicans. (see constituents above) (22)
• Antioxidant / Tuber: Study evaluated the antioxidant activity of D. bulifera. Ethanolic extracts of tuber were screening for enzymation and nonenzymatic antioxidant activity. Results showed impressive level of enzymatic antioxidants i.e., GPx, CAT, SOD. It also contained a commendable store of non enzymatic antioxidants i.e., reduced GSH, vitamin C and vitamin E. Dioscora bulbifera can provide antioxidant needs in the diet. (24)
• Bioactivity / Toxicity / Detoxification / Review: While studies have verified D. bulbifera's efficacy in treating a wide rang of diseases (goiter, pyogenic skin infections, orchitis, cancer, pharyngitis), more studies have also reported liver and renal damage. Possible reasons for toxicity include toxic effects of diosbulbin B and D on hepatocytes, inhibition of antioxidant enzymes in liver mitochondria, and inhibition of enzymes that metabolize the herb's components. Synergistic compatibility detoxification may help reduce toxic effects. (26)
Hepatotoxic Equivalent Combinatorial Markers / Tubers: Study proposed a screening strategy "hepatotoxic equivalent combinatorial markers (HECMs)" for a hepatotoxic herbal medicine. A total of 40 compounds were detected and characterized. Two diterpenoid lactones, 8-epidiosbulbin E acetate (EEA) and diosbulbin B (DIOB), were discovered as the most hepatotoxicity-related markers. (27)
• Neuropharmacological Activity
/ CNS Depressant / Sedative / Anxiolytic / Tubers: Study evaluated the neuropharmacologicl activity of tubers of D. bulbifera using various experimental models. Phytochemical screening yielded terpenoids, saponins, glycosides, flavanoids, alkaloids, carbohydrates and proteins. The DBE exhibited central nervous depressant action in general behavioral tests. There was significant (p<0.05) reduction of spontaneous motor activity and prolonged phenobarbitone induced hypnosis in mice. Anxiolytic activity using elevated plus maze test showed significantly increase number of entries and time spent in open arms. CNS depressant action was indicated by significant reduction of rectal temperature in mice. Results suggest central nervous depressant/sedative and anxiolytic potential which may be attributed to combined effects of psychoactive principles. (29)
• Anticancer Activity / Diosbulbin B: Study evaluated various extract fractions and compound biosbulbin B isolated from D. bulbifera for antitumor activity. Fractions B and C decreased tumor weight in S180 and H22 tumor bearing mice. Study showed compound disobulbin B demonstrated antitumor effect in a dose dependent manner at dose of 2 to 16 mg/kg without significant toxicity in vivo. The compound biosbulbin B was the major antitumor compound of D. bulbifera. (30)
• Anti-Hypernociceptive / Bulbils: Study evaluated the antinociceptive effects from extracts of bulbils of Dioscorea bulbifera in one model of chronic inflammatory and neuropathic models of pain in mice. Results showed significant dose dependent inhibition of the different models of pain used. Findings suggest the analgesic effect of the extract could be from activation of NO/GMPc/AT dependent potassium channel. (31)
• Immunomodulatory Potential: Study evaluated the comparative immunomodulatory potential of Amarkand species. Findings showed a significant effect on the modulation of immune reactivity in the bulbils of D. bulbifera and tubers of Eulophia orcreata. D. bulbifera showed greater neutrophil adhesion and a significant increase in delayed type hypersensitivity response. Results suggest both have immunomodulatory potential and provides basis for use in traditional remedies. (32)
• Phenolic Compounds / Antioxidant / Rhizomes: Study of rhizomes of D. bulbifera isolated one new bibenzyl (7), one new diarylheptanone, diobulbinone A (18), along with 16 known compounds, (1-6 and 8-17). Compound 7 showed high antioxidant capacity in FRAP assay and DPPH radical scavenging activity. (33)
• HPLC Determination of Diosbulbin B: Study reports on a simple, quick. acccurate and suitable method for the determination of Disobulbin B in Dioscorea bulbifera. The method showed a linear relationship for salicylic acid. Average recovery was 99.80 with RSD of 0.57%. (34)
• Effect of Steam Blanching and Sulphiting on Antidiabetic Potential of Aerial Yam: Study evaluated the effect of processing (sulphiting and steam blanching) of aerial yam (D. bulbifera) amala flour on hypoglycemic and hypolipidemic effect on alloxan induced diabetic rats. Results showed steam blanched and sulphited D. bulbifera showed significant hypoglycemic effects while the sulphited sample showed adverse effect on the liver and kidney. Possible mechanism of action of D. bulbifera hypoglycemmic action may be via promotion of regeneration of ß-cells or protection of these cells from destruction. (35)
Cardioprotective / Steroidal Saponin Diosgenin / Protection of Cardiac Cells from Hypoxia- Reoxygenation Injury: Study evaluated the cardioprotective role of diosgenin, a steroidal saponin, on hypoxia-reoxygenation (HR) in H9c2 cardiomyoblast cells. Results showed cardioprotection by mitigation of HR injury through diosgenin supplementation. (37)
• Antibacterial / Bulbils: Study evaluated the methanol extract, fractions (DBB1 and DBB2) and six compounds isolated from bulbils of D. bulbifera for antimicrobial activities against Mycobacteria and MDR phenotypes expressing active efflux pumps. Results showed that when tested alone, the crude extract, fractions, and compounds 2-5 prevented growth of all 15 studied microorganisms. Study suggests the crude extract and compound 3 have potential as antimicrobials against MDR bacteria. (39)
• Metabolism of Diterpenoid Lactones / Tubers: Diterpenoid lactones have been reported to be the main hepatotoxic constituents in D. bulbifera tubers. Study evaluated the main diosbulbin metabolites DIOA, DIOC, DIOG, DIOM, and DIOF in adult zebrafish. Results suggest that hepatocyte metabolism may be the major route of clearance for DLs. Findings provide important information for the understanding of the metabolism of DLs in DBT. (41)
• Anthelmintic / Earthworms and Liverflukes / Bulbils: Study evaluated the in vitro anthelmintic activity of methanolic extracts of flesh and peel of bulbils of D. bulbifera on Fasciola gigantica and Pheretima posthuma. Results suggest D. bulbifera possesses in vitro anthelmintic compounds. The peel was more potent at 100 mg/ml, in measures of time of paralysis and death. Albendazole was used as standard reference. (42)