- Etymology: Species name "Thomsoniae" is in honor or Rev. William Cooper Thomson (d: 1878), a missionary, physician, and plant collector in Nigeria and Calabar. (2)
- Clerodendrum derives from Greek and means "chance tree."
- The common name "bleeding heart bower" refers to the species' combination of white and red flowers. (2)
- Clerodendrum is a genus of about 500 species belonging to the Lamiaceae family.
- The Chinese name "Long tu zhu" means "dragon spits a pearl," which refers to the blooming stage when the red "pearl" of a corolla comes out of the calyx.
Clerodendrum thomsoniae is a slightly woody vine, twining attaining 3-7 meters in length. Stems are obtusely quadrangular, puberulent; stipules absent. Leaves are opposite, 5.2 -14 by 2.7 -7 cm. elliptical or lanceolate, chartaceous, the apex acuminate, the base obtuse or rounded, the margins entire or remotely sinuate; upper surface puberulent, dark green, dull; the lower surface puberulent, pale green, with numerous dots, the veins prominent; petioles 1 - 2.8 cm long, sulcate, puberulent. Inflorescences of axillary cymes; bracts minute, subacute. Calyx more or less urceolate, 1.5 m- 2.5 cm long, white, puberulent, the sepals lanceolate or elliptic-lanceolate, connate at the base, acuminate at the apex; corolla red or crimson, hypocrateriform, ca. 2 cm long, the tube quite narrow, the lobes rounded, filaments pink, twice as long as the corolla; style p[ink, as long as the filaments (Acevedo-Rodriguez, 2005). Fruit drupaceous, covered by the calyx, 2.3 cm long, round or depressed-globose, 10-14 mm long and wide, glossy black, 2-bilobed seeds; seeds oblong (Rueda, 1993). (2)
- Cultivated for ornamental purposes.
- Native to Cameroon, Gambia, Ghana, Gulf of Guinea Is., Nigeria, Senegal, Sierra Leone, Zaire.
- Widely cultivated in the tropics and subtropics around the world.
- Usually cultivated as garden ornamental but occurs outside of cultivated areas.
- Known to be naturalized in many introduced places.
- Considered invasive in many countries.
- Listed as an environmental weed in the Global Compendium of Weeds. (2)
- Phytochemical studies have yielded flavonoids, phenolic compounds, terpenoids and steroids with significantly high amounts of flavonoids and phenolic compounds. (see study below) (7)
- Phytochemical studies of various extracts yielded:(chloroform) carbohydrates, flavonoids, phenols; (ethyl acetate) alkaloids, glycosides, terpenoids, amino acids, steroids, flavonoids, phenols (ethanol) alkaloids, carbohydrates, glycosides, amino acids, steroids, flavonoids (water) carbohydrates, glycosides, proteins, amino acids, steroids, saponins. Petroleum ether extract yielded no constituents. (14)
- Studies have suggest antioxidant, anticonvulsant, antidiabetic, hypolipidemic properties.
Leaves, roots, flowers.
- Leaves used to treat obesity.
- In Cameroon, decoction of leaves and roots used for convulsions, headaches, and parasitic diseases. (9) Leaves used for treatment of diabetes and related disorders. (10)
- Poultice of leaves and flowers applied to bruises, cuts, skin rashes and sores, Macerated leaves used as shampoo to prevent scalp scaling and treat dandruff. (DeFilipps et al) (11)
- In Guyana, pounded leaves and flowers applied to bruises and cuts. (12)
• Cytotoxicity / Breast Cancer Cell Line / Aerial Parts: Study evaluated the in vitro cytotoxic effect of different solvent extracts and active fractions of aerial parts of C. thomsoniae by MTT assay of different human cancer cell lines i.e. MCF-7, Hep-G2, A549, HT-29, MOLT-4, and vero cell lines. The ethyl acetate extracts were used for fractionation and repeat MTT assay of MCF-7 cell line found fraction F5 was the most active fraction with IC50 17.33 ± 0.54 µg/mL. Study suggests C. thomsoniae possess significant cytotoxicity especially for breast cancer cell lines. (3)
• Antiproliferative / DMBA- Induced Breast Cancer / Aerial Parts: Study evaluated the anti-cancer activity of ethyl acetate fractions of Clerodendrum thomsoniae in female Sprague-Dawley rats with DMBA induced breast cancer. There were less necrosis and infiltration in breast cancer treated with doxorubicin as well as EACT. The curative effect was dose-dependent in animals treated with EACT. Some of the damaged breast patters were restored to normal. GC-MS study showed 2,4-bis(1-phenylethyl)-phenol (38%) to be the major compound present in EACT. (4)
• Acute and Subacute Toxicity Studies / Aerial Parts: Study evaluated the acute and subacute toxicity of Clerodendrum thomsoniae in male and female rats using OECD guidelines. Results showed a single dose of up to 2000 mg/kg orally caused no toxicity signs or mortality in mice.. In subacute toxicity testing in rats, daily doses of 150, 300, and 600 mg/kg for 28 days did not induce major changes in hematological or biochemical parameters. Histopath exam showed normal architecture without any morphological disturbances. (5)
• Hypolipidemic / Blood Glucose Reduction / Leaves: Study evaluated aqueous extract of leaves for lipid-lowering and antioxidant potential on hyperlipidemic rats induced by a high fat diet. Results showed decreased total cholesterol, triglycerides, LDL and VLDL cholesterol along with an increase in HDL cholesterol in rats. A dose-dependent result was noted with the highest dose of 1250 mg/kg showing highest [percentage change. There was also significant dose dependent reduction in blood glucose and abdominal fat contents There was also significant dose dependent increase in catalase and super oxide dismutase activities. (6)
• Bioactive Potentials: Study evaluated the bioactive potentials of the plant by different in vitro assays. A methanolic extract exhibited potent antioxidant and radical scavenging activities, reducing power, lipid peroxidation inhibition ability, capacity to inhibit RBC hemolysis and along with significant acetylcholinesterase and NADH oxidase inhibitory activities. (7)
• Anti-Breast Cancer / 2,4-bis (1-phenylethyl)-Phenol / Aerial Parts: Study isolated 2,4-bis(1-phenylethyl)-phenol from aerial parts and evaluated its cytotoxicity on human breast cancer cells. Its IC50 was calculated as 12.58 µg/mL. The EtBr assay showed early apoptotic cells, late apoptotic cells, necrotic cells, and dead cells with with characteristic fluorescence. Results suggest that 2,4-bis(1-phenylethyl)-phenol is a candidate for breast cancer therapy via apoptosis activation, (8)
• Antidiabetic / Leaves: Study evaluated the antidiabetic effect of aqueous extract of leaves on diet and dexamethasone induced diabetic rats. The extract significantly reduced blood glucose levels. The reduction in blood sugar was highest with dose of 1250 mg/kg gave the highest reduction rate of 30.86% (73.52±0.71 mg/dL) compared to metformin 38 mg/kg (70.21 ±0.89 mg/dL) as control with no significant difference (p<0.05). The antidiabetic effect was attributed to an insulin stimulating effect. (10)
• Anticonvulsant / Sedative: In a study of medicinal plants used in traditional medicine to treat epilepsy, Clerodendrum thomsoniae showed protective activity against PIC- and PTZ-induced convulsions in mice. Clerodendron thomsoniae was one of the more potent plants to induce sedation. (13)