Antiparasitic activities of two sesquiterpenic lactones isolated from Acanthospermum hispidum D.C

in Journal of Ethnopharmacology (2012), 141(0), 411-417

Ethnopharmacological relevance : Aerial parts of Acanthospermum hispidum D.C. are often used by traditional healers in Benin for various diseases and especially for malaria Aim of the study : Identify ... [more ▼]

Ethnopharmacological relevance : Aerial parts of Acanthospermum hispidum D.C. are often used by traditional healers in Benin for various diseases and especially for malaria Aim of the study : Identify active compounds from extracts of Acanthospermum hispidum D.CV. leaves previously shown to possess antimalarial properties and analyse in vivo activity and toxicity of crude extracts. Materials and methods : Compounds were isolated from aerial part of A. hispidum D.C. and structurally elucidated using extensive spectroscopic analysis. Antiplasmodial activity was evaluated in vitro against a chloroquinosensitive strain of Plasmodium falciparum (3D7) using the measurement of the plasmodial lactate dehydrogenase activity and in vivo against P. berghei berghei by the 4-days suppressive test. Selectivity of extract and purified compounds on Plasmodium parasites were evaluated by using MTT test on J774 macrophage like murine cells and WI38 human normal fibroblasts and also against two other parasites: Trypanosoma brucei brucei and Leishmania mexicana mexicana. Acute and sub-acute toxicities of a crude extract were evaluated on mice. Results : Two known sesquiterpenic lactones were isolated: 1 (15-acetoxy-8β-[(2-methylbutyryloxy)]-14-oxo-4, 5-cis-acanthospermolide) and 2 (9α-acetoxy-15-hydroxy-8β-(2-methylbutyryloxy) -14-oxo-4, 5-trans-acanthospermolide). 1 and 2 showed in vitro antiplasmodial activity against the chloroquino-sensitive strain (3D7) with IC50 of 2.9 ± 0.5 and 2.23 ± 0.09 μM respectively. Only 2 showed a high selectivity index (SI: 18.4) on Plasmodium compared to cytotoxicity against human fibroblasts cell line (WI38). 1 and 2 also showed interesting antiparasitic activities in vitro against Trypanosoma brucei brucei (IC50 of 2.45 ± 0.49 and 6.36 ± 1.42 μM respectively) and Leishmania mexicana mexicana (IC50 of 0.94 ± 0.05 and 2.54 ± 0.19 μM respectively). Furthermore, crude acidic water extract and fractions containing one of the two isolated compounds displayed a weak in vivo antimalarial activity against P. berghei berghei with a long half-life causing a delayed effect. In vivo acute (2000 mg/kg) and sub-acute (1000 mg/kg) toxicity tests on the crude acidic water extract did not show toxicity. Conclusion : Crude acidic water extract, fractions and pure isolated compounds from A.hispidum showed promising in vitro antiplasmodial activity. Despite our study did not show in vivo acute and subacute toxicities of the crude acidic water extract, its weak in vivo antimalarial activity and the in vitro cytoxicity of pure compounds and enriched extracts containing 1 and 2 indicate that the aerial parts of A. hispidum should be used with caution for malaria treatments. [less ▲]

Application of experimental design for the HPLC-UV-MS separation of aporphine alkaloids from leaves of Spirospermum Penduliflorum thouars

Poster (2010, September)

Simultaneous quantification os asiaticoside, asiatic acid, madecassoside and madecassic acid in leaves of Centella asiatica (L.) urb.

Poster (2010)

Antimalarial compounds isolated from plants used in traditional medicine.

in Journal of Pharmacy & Pharmacology (2009), 61(11), 1401-33

OBJECTIVES: This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are given ... [more ▼]

OBJECTIVES: This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are given for substances with IC50 values < or = 11 microm. KEY FINDINGS: Malaria is a major parasitic disease in many tropical and subtropical regions and is responsible for more than 1 million deaths each year in Africa. The rapid spread of resistance encourages the search for new active compounds. Nature and particularly plants used in traditional medicine are a potential source of new antimalarial drugs as they contain molecules with a great variety of structures and pharmacological activities. SUMMARY: A large number of antimalarial compounds with a wide variety of structures have been isolated from plants and can play a role in the development of new antimalarial drugs. Ethnopharmacological approaches appear to be a promising way to find plant metabolites that could be used as templates for designing new derivatives with improved properties. [less ▲]

In vitro evaluation of antiplasmodial activity of plant samples used in traditional medicine in Benin

in Planta Medica (2008), 74(9), 1140-1140

Validation of a method for the determination of sterols and triterpenes in the aerial part of Justicia anselliana (Nees) T. Anders by capillary gas chromatography.

in Journal of Pharmaceutical & Biomedical Analysis (2008), 48(4), 1127-35

An accurate and sensitive method, combining soxhlet extraction, solid phase-extraction and capillary gas chromatography is described for the quantitative determination of one triterpene (lupeol) and three ... [more ▼]

An accurate and sensitive method, combining soxhlet extraction, solid phase-extraction and capillary gas chromatography is described for the quantitative determination of one triterpene (lupeol) and three sterols (stigmasterol, campesterol and beta-sitosterol) and the detection of another triterpene (alpha-amyrin) from the aerial part of Justicia anselliana. This is the first method allowing the quantification of sterols and triterpenes in this plant. It has been fully validated in order to be able to compare the sterol and triterpene composition of different samples of J. anselliana and therefore help to explain the allelopathic activity due to these compounds. This method showed that the aerial part of J. anselliana contained (292+/-2)mg/kg of lupeol, (206+/-1)mg/kg of stigmasterol, (266+/-2)mg/kg of campesterol and (184+/-9)mg/kg of beta-sitosterol. [less ▲]

Induction of Apoptosis in Human Promyelocytic Leukemia Cells by a Natural Trachylobane Diterpene

in Anticancer Research (2005), 25(1A), 363-368

Background: Trachylobane diterpenes are secondary metabolites quite rare in nature and their bioactivities are poorly known. Recently we have described the cytotoxic activity of ent- trachyloban-3‚-ol ... [more ▼]

Background: Trachylobane diterpenes are secondary metabolites quite rare in nature and their bioactivities are poorly known. Recently we have described the cytotoxic activity of ent- trachyloban-3‚-ol isolated from the leaves of Croton zambesicus, a plant used in African folk medicine. Materials and Methods: Cell viability on several cell lines, cell morphology, DNA laddering, annexin V and caspase-3 activation experiments were undertaken in order to analyse the cytotoxicty of trachylobane diterpene and to determine if this compound is able to induce apoptosis. Results: ent-trachyloban-3‚-ol exerts a dose-dependent cytotoxic effect and which varies between cell lines. Induction of apoptosis in HL-60 cells could be detected at a concentration of 50 ÌM after 24-h treatment. Conclusion: We show here, for the first time, that a trachylobane diterpene is able to induce apoptosis in human promyelocytic leukemia cells via caspase-3 activation in a concentration-dependent manner. [less ▲]

Development and validation of a high-performance liquid chromatographic method for quantitative determination of aporphine alkaloids from different samples of Cassytha filiformis L

Conference (2004)

Ent-Trachyloban-3beta-ol, a new cytotoxic diterpene frm Croton zambesicus

in Planta Medica (2002), 68

The dichloromethane extract of leaves of Croton Zambesicus (Euphorbiaceae) showing in vitro cytotoxicity against huma cervix carcinoma cells was investigated in order to identify its active compounds. A ... [more ▼]

The dichloromethane extract of leaves of Croton Zambesicus (Euphorbiaceae) showing in vitro cytotoxicity against huma cervix carcinoma cells was investigated in order to identify its active compounds. A bio-guided fractionation by HSCCC followed by MPLC led us to isolate a trachylobane diterpene, ent-trachyloban-3beta-ol, with cytotoxic properties (IC50 on HeLa cells = 7.3 ùg/ml). This is the first report on the cytotoxicity of a trachylobane diterpene. [less ▲]

Evaluation of the antitrypanosomal activity of several plants traditionally used in Benin to treat sleeping sickness

Poster (2001)