Objective:To validate scientifically the traditional use of Salacia leptoclada Tul. (Celastraceae) (S. leptoclada) and to isolate and elucidate the structure of the biologically active compound.
Methods:Bioassay-guided fractionation of the acetonic extract of the stem barks of S. leptoclada was carried out by a combination of chromatography technique and biological experiments in viro using Plasmodium falciparum and P388 leukemia cell lines as models. The structure of the biologically active pure compound was elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.
Results:Biological screening of S. leptoclada extracts resulted in the isolation of a pentacyclic triterpenic quinone methide. The pure compound exhibited both in vitro a cytotoxic effect on murine P388 leukemia cells with IC50 value of (0.041±0.020) μg/mL and an antiplasmodial activity against the chloroquine-resistant strain FC29 of Plasmodium falciparum with an IC50 value of (0.052±0.030) μg/mL. Despite this interesting anti-malarial property of the lead compound, the therapeutic index was weak (0.788). In the best of our knowledge, the quinone methide pentacyclic triterpenoid derivative compound is reported for the first time in S. leptoclada.
Conclusions:The results suggest that furthers studies involving antineoplastic activity is needed for the development of this lead compound as anticancer drug.

Objective:To isolate and characterize the cytotoxic compounds from Diospyros quercina (Baill.) G.E. Schatz&Lowry (Ebenaceae).
Methods: An ethno-botanical survey was conducted in the south of Madagascar from July to August 2010. Bio-guided fractionation assay was carried out on the root bark of Diospyros quercina, using cytotoxicity bioassay on murine P388 leukemia cell lines as model. The structures of the cytotoxic compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.
Results: Biological experiments resulted in the isolation of three bioactive pure compounds (named TR-21, TR-22, and TR-23) which exhibited very good in vitro cytotoxic activities with the IC50 values of (0.017 5±0.0060) μg/mL, (0.089±0.005) μg/mL and (1.027±0.070) μg/mL respectively. Thus, they support the claims of traditional healers and suggest the possible correlation between the chemical composition of this plant and its wide use in Malagasy folk medicine to treat cancer.
Conclusions:The ability of isolated compounds in this study to inhibit cell growth may represent a rational explanation for the use of Diospyros quercina root bark in treating cancer by Malagasy traditional healers. Further studies are, therefore, necessary to evaluate the in vivo anti-neoplastic activity of these cytotoxic compounds as effective anticancer drugs.

Objective: To evaluate the anticonvulsant effect of the essential oil of Myrothamnus moschatus (M. moschatus) in convulsion induced by pentylenetetrazole and picrotoxin in rodent models. Methods: The essential oil of the aerial parts of M. moschatus was extracted by steam distillation. Thereafter, it was injected subcutaneously to rats and mice at escalating doses (0.1-0.8 mL/kg). Ten minutes after drug injection, pentylenetetrazole was injected intraperitoneally to rats and picrotoxin was administered to mice by the same route. Diazepam served as the positive control. Every single animal was placed into transparent cage and observed for convulsive behavior for 30 min by using ordinary security cameras connected to a video recorder. Death occurring for a period of 24 h was also recorded. Results: The essential oil at 0.8 mL/kg completely arrested the pentylenetetrazole-induced convulsion without any sedative effect and delayed its appearance at lower doses, but showed moderate activities on picrotoxin-induced convulsion. For the rats treated with pentylenetetrazole alone, the mortality was 100% within 1 h, but for the rats pre-treated with the essential oil, the mortality was 0%. For the mice treated with picrotoxin, the mortality rate was also 100%, while 20%-100% died in those that had been pre-treated with the oil. Conclusions: The results confirmed at least partly the traditional uses of the smoke of M. moschatus for the management of convulsion, and implied that the essential oil may inhibit the convulsion by GABAergic neuromodulation.

OBJECTIVETo isolate and characterize the cytotoxic compounds from Diospyros quercina (Baill.) G.E. Schatz & Lowry (Ebenaceae).

METHODSAn ethno-botanical survey was conducted in the south of Madagascar from July to August 2010. Bio-guided fractionation assay was carried out on the root bark of Diospyros quercina, using cytotoxicity bioassay on murine P388 leukemia cell lines as model. The structures of the cytotoxic compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.

RESULTSBiological experiments resulted in the isolation of three bioactive pure compounds (named TR-21, TR-22, and TR-23) which exhibited very good in vitro cytotoxic activities with the IC50 values of (0.017 5±0.0060) µg/mL, (0.089±0.005) µg/mL and (1.027±0.070) µg/mL respectively. Thus, they support the claims of traditional healers and suggest the possible correlation between the chemical composition of this plant and its wide use in Malagasy folk medicine to treat cancer.

CONCLUSIONSThe ability of isolated compounds in this study to inhibit cell growth may represent a rational explanation for the use of Diospyros quercina root bark in treating cancer by Malagasy traditional healers. Further studies are, therefore, necessary to evaluate the in vivo anti-neoplastic activity of these cytotoxic compounds as effective anticancer drugs.