Phillipson JD. A matter of some sensitivity. Phytochemistry, 1995 Apr
Croton lechleri L. (Euphorbiaceae), a plant from the Upper Amazon Valley of Peru, yielded the alkaloid taspine. The anti-inflammatory activity of taspine hydrochloride was studied using the carrageenan-induced pedal edema method, the cotton pellet-induced granuloma method, and the adjuvant polyarthritis model.
Taspine is the cicatrizant principle in Sangre de Grado extracted from Croton lechleri.
Vaisberg AJ; Milla M; Planas MC; Cordova JL; de Agusti ER; Ferreyra R; Mustiga MC; Carlin L; Hammond GB
Planta Med, 55: 2, 1989 Apr, 140-3
Sangre de Grado extract used by Peruvian natives as a cicatrizant agent, was collected from trees of the species Croton lechleri growing in the Peruvian jungle. The Sangre de Grado was found to contain one alkaloid identified as taspine and which was shown to be the active cicatrizant principle by an in vivo test in mice. This alkaloid exhibited a dose-related cicatrizant effect and an ED50 of 0.375 mg/kg. Experiments with taspine hydrochloride in order to study its mechanism of action in cell culture systems showed that the alkaloid was non-toxic to human foreskin fibroblasts at concentrations below 150 ng/ml and that it had no effect on cell proliferation. On the other hand, taspine hydrochloride was found to increase the migration of human foreskin fibroblasts. This effect on the migration of fibroblasts is probably the mechanism by which Sangre de Grado and taspine hydrochloride accelerate the wound healing process. Using the two-stage mouse skin carcinogenesis system, we have been able to show that neither Sangre de Grado nor taspine hydrochloride had carcinogenic or tumour promoter activity after 17 months of treatment.
Isolation of a dihydrobenzofuran lignan from South American dragon’s blood (Croton spp.) as an inhibitor of cell proliferation.
Pieters L; de Bruyne T; Claeys M; Vlietinck A; Calomme M; vanden Berghe D
University of Antwerp, Belgium.
J Nat Prod, 56: 6, 1993 Jun, 899-906
Dragon’s blood is a red viscous latex extracted from the cortex of various Croton spp. (Euphorbiaceae), most commonly Croton lechleri, Croton draconoides (or Croton palanostigma), and Croton erythrochilus. It is used in South American popular medicine for several purposes, including wound healing. Bioassay-guided fractionation of dragon’s blood, using an in vitro test system for the stimulation of human umbilical vein endothelial cells, has resulted in the isolation of a dihydrobenzofuran lignan, 3′,4-O-dimethylcedrusin or 4-O-methyldihydrodehydrodiconiferyl alcohol [2-(3′,4′-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-methoxybenzo furan-5- propan-1-ol]  as the biologically active principle. A related compound, 4-O-methylcedrusin [2-(3′,4′-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-hydroxybenzo furan-5- propan-1-ol] , and the alkaloid taspine , also isolated from dragon’s blood, were not active in the same assay. A cell proliferation assay, measuring the incorporation of tritiated thymidine in endothelial cells, showed that compound 1 did not stimulate cell proliferation, but rather inhibited thymidine incorporation, while protecting cells against degradation in a starvation medium.
Chen ZP; Cai Y; Phillipson JD
Department of Pharmacognosy, School of Pharmacy, University of London, U.K.
Planta Med, 60: 6, 1994 Dec, 541-5
Three in-vitro assays have been adopted to examine the cytotoxicity and anti-bacterial activity of the blood-red sap of Croton lechleri from Ecuador, and to examine its effect upon the proliferation of endothelial cells. The sap was found not to be cytotoxic. Several simple phenolic compounds and diterpenes showed a potent anti-bacterial activity. The sap has little effect upon the proliferation of endothelial cells, and no single active ingredient was identified. A mechanism for the wound-healing property of the sap has been proposed.
The development of sensitive chromatographic and spectroscopic techniques for the isolation and structure determination of natural products has greatly facilitated phytochemical investigations. Chemical investigations of herbarium material have resulted in the isolation of indole, quinoline and isoquinoline alkaloids from a wide number of plants. Examples of novel natural products from higher plants are given and include alkaloids, terpenoids, phenolics and quinones. Some plants investigated have not yielded the types of constituents which would have been predicted from them. Plant tissue cultures provide alternative sources of biologically active compounds and examples investigated include Cinchona, Ailanthus, Brucea and Artemisia for antiprotozoal compounds and Datura for tropane alkaloids. Biological tests are useful for bioassay-guided fractionation of plant extracts and examples of the isolation of a series of natural products with antiprotozoal and cytotoxic activities are given. Chemical and biological investigations into the traditional medicine Dragon’s blood (Croton lechleri) from S. America and a Chinese prescription for the treatment of atopic eczema are described. The use of radio-ligand binding assays for the detection of a wide range of biological activities is discussed. Sensitivity of chemical and biological techniques has greatly improved prospects for finding new drug entities from plants and for investigating traditional medicines. Basic phytochemical investigations should continue to be encouraged especially in view of the rapid loss of plant species.