Gen info
• Strophantus is a genus of 35-40 species of flowering plants in the Apocynaceae family
• Strophos anthos, "twisted cord flower," derives from the long twisted threadlike segments of the corolla. (4)

Botany
Sarasara is an erect, somewhat climbing shrub about 3 meters high. Leaves are oblong-elliptic, 8 to 13 centimeters long, 3 to 5 centimeters broad, and pointed at both ends. Flowers are white. Sepals are lanceolate, about 4 millimeters long. Corolla tube is 10 to 12 millimeters long; the corolla lobes are continued into a slender, tail-like projection, about 10 millimeters long. Fruit consists of a double follicle, each about 15 to 17 centimeters long and 4 centimeters wide, with a pointed tip. Follicle is somewhat woody and contains numerous seeds, each of which terminate in a long, slender projection with numerous, long hairs.

Quisumbing's compilation publishes S. letei as closely allied to S. cumingii, differing only in its smaller flowers and smooth filaments. The Plant List lists both S. letei and S. cumingii as synonyms of S. caudatus. (see: Abuhad-baging / Strophanthus cumingii)

Distribution
- Found in La Union Province, growing in thickets at low altitude.
- S. caudatus is reported in E. Asia- Philippines, southern China, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia, New Guinea.

Constituents
- Bark of roots and stems yield saponin, 2.1% in roots, 0.9% in bark. It is somewhat similar to pseudostrophanthin. In animal studies, the saponin, in the form of an amorphous powder, increases the tone and augment heart contraction and increases blood pressure. By mouth, the drug produces emesis.
- In biological assay, the powder was found to possess one-twentieth the strength of ouabain.
- Phytochemical screening of 80% ethanol extract of cortex yielded alkaloid, terpenoid, tannin, glycoside, and saponin. (6)

Properties
- Bark of roots.
- Studies have shown positive inotropic and negative chronotropic cardiac effects and a-glucosidase inhibitory property.

Parts used
Bark.

Uses
Folkloric
- The Ayta in Dinalupihan, Bataan, apply stem sap on bleeding wounds. (5)
- In Vietnam, whole plant used for treatment of hypertension. (7)
Others
- In the Philippines, bark is employed as an effective arrow-poison.
- In Vietnam, used as fish poison.

Studies
• Glycosides: The glycosides of Strophanthus cumingii A. DC. were compared with cardiogenic glycosides (digitoxin, ouabain, and strophanthin) by paper chromatography. (2)
• Cardioactivity / Bark: Study evaluated the cardioactivity of bark extract of S. cumingii and its sub-fractions on isolated frog hearts. The hexane fraction was the most cardioactive with maximum 30.58% increase in force of contraction and 38.24% increase in frequency of contraction. The non-polar fraction of the crude extract from bark elicited a positive inotropic and negative chronotropic effect. (3)
• α-Glucosidase Inhibitory Activity: In a study screening 45 samples for in-vitro α-glucosidase activity, 37 samples, including Strophanthus caudatus (Blume.f.) Kurz cortex (IC50 13.93 µg/ml), showed IC50 values between 2.33 µg/ml and 112.02 µg/ml, which were lower than acarbose at 117.20 µg/mL. (6)

Availability
- Wild-crafted.
- Ornamental cultivation.

Additional Sources and Suggested Readings
(1)
Strophanthus caudatus / Synonyms / The Plant List
(2)
Studies on Philippine medicinal plants. I. Paper chormatography and spectrophotometric determination. / Manalo GD, Lleander GC / Philippine Journal of Science, 1961
(3)
THE CARDIOACTIVE SCREENING OF THE EXTRACT FROM THE BARK OF STROPHANTHUS CUMINGII A.DC. (APOCYNACEAE) USING ISOLATED FROG HEART / Maribeth R. Laurente*, Mafel C. Ysrael / Int J Pharm 2015; 5(4): 1048-1050
(4)
Strophanthus / The Full Wiki
(5)
Ethnobotanical Survey of Medicinal Plants used by Ayta Communities in Dinalupihan, Bataan, Philippines / Ourlad Alzeus G. Tantengco, Marlon Lian C. Condes, Hanna Hasmini T. Estadilla, Elena M. Ragragio / Pharmacogn J., 2018; 10(5): pp 859-870
(6)
Screening of α-Glucosidase Inhibitory Activity from Some Plants of Apocynaceae, Clusiaceae, Euphorbiaceae, and Rubiaceae / Berna Elya, Katrin Basah, Abdul Mun’im, Wulan Yuliastuti, Anastasia Bangun, and Eva Kurnia Septiana / Journal of Biomedicine and Biotechnology, 2012; Article ID 281078 / doi:10.1155/2012/281078
(7)
INDIGENOUS KNOWLEDGE OF MUONG AND DAO ETHNIC MINORITY GROUPS IN BA VI NATIONAL PARK, VIETNAM / Dr. Hoang Van Sam / Hanoi, 2010 / The Rufford Small Grants Foundation