Articles

Strophanthus gratus (Wall. & Hook.) Baill.

Last updated: 15 Aug 2016

Scientific Name

Strophanthus gratus (Wall. & Hook.) Baill.

Synonyms

Nerium guineense Brongn. ex Perrot & Vogt, Roupalia grata (Wall. & Hook.) T.Moore & Ayres, Roupellia grata Wall. & Hook., Strophanthus chopraie M.R.Almeida, Strophanthus glaber Cornu ex Holmes, Strophanthus gratus Franch. [Illegitimate], Strophanthus ouaboio Holmes [Invalid], Strophanthus perrotii A.Chev. [Invalid], Strophanthus stanleyanus Hook. [1]

Vernacular Name

English Climbing oleander, smooth strophanthus [2], spider tresses, poison arrow vine [3]
China Xuan hau yang jiao niu [4]
Thailand Baan thon, hom peenang, yan peenang [4]
Cameroon Ine, onaye (Gabon) [5]
Ghana Omaatwa [5]
Sierra Leone Sawai, tsa-wa, gondui [5]
France Strophanthus Glabre du Gabon [3]
Portugal Estrofanto [3].

Geographical Distributions

No documentation.

Botanical Description

Strophanthus gratus is a member of the Apocyanaceae family. It is a liana that could reach up to 25 m long with the stem reaching a diameter of 10 cm. It has clear or white exudates. Older plants often have corky ridges and branches with many lenticels, dark brown or purplish brown. [3]

The leaves decussate oppositely. They are simple and entire without stipules. The petioles are 5-17 mm long and blades 5-18 cm x 2-9 cm. The leaf blade is ovate to elliptical to obovate, base rounded or cuneate and apex acuminate with margins entire. They are thinly coriaceous and glabrous. [3]

The inflorescence is terminal dichasial cyme, on long or short branches or in the forks. The peduncle is 0-6 mm. The flowers are bisexual, regular, 5-merous, and fragrant. [3]

The fruit consists of 2 ellipsoid follicles 23-41 cm x 2-4.5 cm, tapering to a narrow and obtuse apex and ending in a large knob. [3]

The seeds are spindle in shape, measure 12-20 mm x 2.5-4.5 mm, glabrous, slightly rough, at apex is a long beak and in the upper 2.5-4.5 cm are long hairs. [3]

Cultivation

No documentation.

Chemical Constituent

S. gratus has been reported to contain 8-hydroypinoresinol; acolongifloroside K, dambonitol, ouabain, olivil, pinoresinol, sarnovide, strogogenin, strogoside. [3][6][7]

Plant Part Used

Roots, stems, leaves, seeds. [3][8]

Traditional Use

S. gratus in its native land (areas in West Africa and western Central Africa) is used in preparation of arrow poison. The poison is the most rapidly acting one and is said to occur within minutes of penetration. The source of the poison is mainly in the seeds but other parts of the plant is used when seeds are not available. The toxic element had been identified as strophanthin (ouabain). This compound had been adopted by modern pharmaceutical companies and had been used successfully in treating heart failure. [3]

The leaves and stems have been recommended for use in the treatment of inflammatory conditions by many communities in Africa. For gonorrhoea the people of Sierra Leone and Cote d’Ivoire prescribe a decoction of the leaf and stem. The leaf paste is applied on snakebites by the people of Ghana while in Cote d’Ivoire and in Nigeria, this is applied on sores including guinea worm sores. The leaf juice could also be used over these sores. [3][8]

Infusion of the leaves is given for constipation, and when rubbed over the body it helps to cure fever. Crushed leaves could also be used to treat fever. For general weaknesses, fatigue and extreme debility, a decoction of the bark is given by the Ghanaians or by rubbing crushed stems over the body. The root decoction is believed to be an aphrodisiac. [3][8]

Preclinical Data

Pharmacology

Ouabain had been the subject of scrutiny by researchers following the discovery that there is endogenous production of ouabain in humans. It is a cardiac glycoside which specifically inhibits Na+,K+-ATPase and forms the basis of many other activities attributed to it. [9][10][11][12][13][14][15]

Antidiabetic activity

Ouabain was found to have the ability to increase glycogen synthesis in human skeletal muscle cells. An effect mediated by the activation of a Src-, ERK1/2-, p90rsk-, and GSK3-dependent signalling pathway. This effect was found to be additive to insulin’s effect. [9][10]

Neuromuscular junction activity

The inhibition of sodium-potassium ATPase pump by ouabain lead to sodium accumulation in the nerve terminals. Ouabain also causes the increase of acetylcholine release and rapid depletion of synaptic vesicles. This vesicular depletion is due to exocytosis induced by ouabain, and this in turn is dependent on endogenous calcium released from the endoplasmic reticulum and mitochondrial stores. [11]

Cytotoxic activity

Cardiac glycosides ouabain, oleandrin and digoxin have been found to have the ability to induce apoptosis in androgen-independent human prostate cancer and the oestrogen-independent breast cancer (MDA-MB-231). The cell death was associated with early release of cytochrome c from the mitochondria, followed by proteolytic processing of caspases 8 and 3. The proapoptotic effects of the cardiac glycosides were linked to their abilities to induce sustained Ca2+ increases in the cells. Ouabain induces two modes of cytotoxic effect in human hormone-independent prostate cancer. In low concentrations it induces an increase of Par-4 expression and sensitize the cytotoxicity. On the other hand, in high concentrations, it induce a loss of the mitochondrial membrane potential, a sustained ROS production and a severe apoptosis. [12][13][14]

Fibroblast proliferation activity

In low concentrations ouabain was found to induce proliferation of human fibroblasts. Na+-K+ ATPase most probably acts as a transducing receptor. The antiapoptotic action is induced by an increase in the level of phosphorylated extracellular signal-regulated kinases (P-ERK 1/2). At high concentrations it increases intracellular Ca2+ concentration, activate caspase-3 and induce apoptosis in human fibroblast. [15]

Toxicity

The seeds of S. gratus are considered very toxic. Natives of Africa utilize the seeds in their preparation of arrow or blow pipe dart poison. The seeds contain the highest concentration of glycosides i.e. between 4-8% of glycoside mixture comprising of 90-95% ouabain followed by acolongifloroside K and strogoside. Minor components with different aglycones are sarnovide and several sarmentosides. The toxic compounds working together renders the seed ideal for its use as an arrow poison. They have extremely high toxicity, fast in action and very effective. [3]

Clinical Data

No documentation.

Dosage

No documentation.

Poisonous Management

No documentation.

Line drawing

No documentation.

References

  1. The Plant List. Ver1.1. Strophanthus gratus (Wall. & Hook.) Baill. [homepage on the Internet]. c2013 [updated 2012 Mar 23; cited 2016 Aug 10]. Available from: http://www.theplantlist.org/tpl1.1/record/kew-198229
  2. Herbal Medicine Research Centre, Institute for Medical Research. Compendium of medicinal plants used in Malaysia. Volume 2. Kuala Lumpur: HMRC IMR, 2002; p. 364.
  3. Schmelzer GH, Gurib-Fakim A, editors. Plant Resources of Tropical Africa 11(1): Medicinal plants 1. Wageningen, Netherlands: PROTA Foundation/Backhuys Publishers/CTA, 2008; p. 546-549.
  4. Quattrocchi U. CRC world dictionary of medicinal and poisonous plants: Common names, scientific names, eponyms, synonyms, and etymology. Volume V R-Z. Boca Raton, Florida: CRC Press, 2012; p. 425-426.
  5. Hanelt P, editor. Mansfeld's encyclopedia of agricultural and horticultural crops: (except ornamentals). Berlin: Springer-Verlag, 2001; p. 1749.
  6. Cowan S, Stewart M, Abbiw DK, Latif Z, Sarker SD, Nash RJ. Lignans from Strophanthus gratus. Fitoterapia. 2001;72(1):80-82.
  7. Nishibe S, Hisada S, Inagaki I. The cyclitols of Ochrosia nakaiana, Plumeria acutifolia and Strophanthus gratus. Phytochemistry. 1971;10(10):2543.
  8. Vardhana R. Direct uses of medicinal plants and their identification. New Delhi: Sarup & Sons, 2008; p. 330.
  9. Kotova O, Al-Khalili L, Talia S, et al. Cardiotonic steroids stimulate glycogen synthesis in human skeletal muscle cells via a Src- and ERK1/2-dependent mechanism. J Biol Chem. 2006;281(29):20085-20094.
  10. Kotova O, Galuska D, Essén-Gustavsson B, Chibalin AV. Metabolic and signaling events mediated by cardiotonic steroid ouabain in rat skeletal muscle. Cell Mol Biol. 2006;52(8):48-57
  11. Amaral E, Leite LF, Gomez MV, Prado MAM, Guatimosim C. Ouabain evokes exocytosis dependent on ryanodine and mitochondrial calcium stores that is not followed by compensatory endocytosis at the neuromuscular junction. Neurochem Int. 2009;55(6):406-413.
  12. McConkey DJ, Lin Y, Nutt LK, Ozel HZ, Newman RA. Cardiac glycosides stimulates Ca2+ increases and apoptosis in androgen-independent, metastatic human prostate adenocarcinoma cells. Cancer Res. 2000;60(14):3807-3812
  13. Huang YT, Chueh SC, Teng CM, Guh JH. Investigation of ouabain-induced anticancer effect in human androgen-independent prostate cancer PC-3 cells. Biochem Pharmacol. 2004;67(4):727-733.
  14. Winnicka K, Bielawski K, Bielawska A, Miltyk W. Apoptosis-mediated cytotoxicity of ouabain, digoxin and proscillaridin A in the estrogen independent MDA-MB-231 breast cancer cells. Arch Pharm Res. 2007;30(10):1216-1224.
  15. Winnicka K, Bielawski K, Bielawska A, Miltyk W. Dual effects of ouabain, digoxin and proscillaridin A on the regulation of apoptosis in human fibroblasts. Nat Prod Res: Formerly Nat Prod Lett. 2010;24(3):274-285.