Yves Pélissier

In vitro antiplasmodial activity of extracts of Alchornea cordifolia and identification of an active constituent: ellagic acid

Extracts of leaves of Alchornea cordifolia were studied for their antiplasmodial activities. Chloroformic and ether extracts were found to be inactive while the ethanolic extract exhibited mild in vitro activity against Plasmodium falciparum. Fractionation of this extract led us to isolate ellagic acid as the active constituent of the extract with IC(50) in the range of 0.2-0.5 microM. Cytotoxicity of ethanolic fraction and ellagic acid was also estimated on human fibroblasts cells (IC(50) on Hela cells = 7.3 microM at 24 h for ellagic acid).

Composition and antimalarial activity in vitro of volatile components of lippia multiflora

The essential oil of Lippia multiflora was prepared by hydrodistillation of leaves and stalks and characterized by GC and mass spectroscopy. The oil was tested for antimalarial activity on in vitro cultures of Plasmodium falciparum (FcB1-Columbia chloroquine-resistant strain and F32-Tanzania chloroquine-sensitive strain). The dilutions inhibiting the in vitro growth of the parasite by 50% 24 and 72 hr after administration of the essential oil to the parasite culture were 1/12,000 and 1/21,000, respectively. When tested on a highly synchronized culture, the essential oil inhibited growth mostly at the trophozoite-schizont step, indicating a potential effect on the first nuclear division of the parasite.

In vitro antimalarial activity of eight essential oils

Abstract Essential oils of eight plants were prepared by hydrodistillation of leaves and twigs (stems) of Artemisia vulgaris, Eucalyptus globulus, Myrtus communis, Juniperus communis, Lavandula angusti/olia, Origanum vulgare, Rosmarinus officinalis and Salvia officinalis. Their oil components were characterized by GC and MS. These oils were then tested for in vitro antimalarial activity on Plasmodium falciparum. Two strains of P. falciparum were tested: FcBl-Columbia (chloroquine-resistant) and a Nigerian chloroquine-sensitive strain. Concentrations inhibiting 50% of the parasite in vitro growth, obtained after 24 and 72 h contact between the oil and the parasite culture, ranged from 150 μg/mL to 1 mg/mL. The best results were obtained with Myrtus communis and Rosmarinus officinalis oils which inhibited P. falciparum at concentrations ranging from 150 to 270 μg/mL.

In vitro antiplasmodial activity of stem and root extracts of Nauclea latifolia S.M. (Rubiaceae).

Aqueous extracts from Nauclea latifolia S.M. (Rubiaceae), a plant commonly used in Ivory Coast by traditional healers for the treatment of malaria, were tested on two strains of Plasmodium faliparum: FcB1-Colombia (chloroquine-resistant) and a Nigerian strain (chloroquine-sensitive). The extracts were obtained from stems and roots of the plant in two forms, infusion and decoction, both methods used by most traditional healers. The in vitro activity of N. latifolia extracts on P. falciparum was assessed both visually and by a radioactive method. The visual analysis allowed determination of the time of extract action on the erythrocytic cycle, as well as the parasitic stage of most inhibitory effect. Similar results were obtained applying fresh, frozen or lyophilized extracts. The IC50 values determined were within the range already reported for other antimalarial plants such as Azadirachta indica A. Juss (Meliaceae) or Artemisia annua L. (Asteraceae). Aqueous extracts of N. latifolia inhibited P. falciparum (FcB1 strain) mainly at the end of the erythrocytic cycle (32nd to 48th hour).

Antiplasmodial activity of plant extracts used in west African traditional medicine

Five plants originating from Ivory Coast were selected after an ethnobotanical survey, Alchornea cordifolia, Mitragyna inermis, Nauclea diderrichii, Pterocarpus santalinoides, and Terminalia glaucescens. Traditional healers for the treatment of malaria commonly used these plants. Extracts of these plants were tested on three strains of Plasmodium falciparum, FcB1-Colombia and FcM29-Cameroon (chloroquine-resistant strains) and a Nigerian chloroquine-sensitive strain. Extracts were obtained by preparing decoction in water of the powdered plant, the technique used by most of the traditional healers. A radioactive micromethod allowed the evaluation of the in vitro activity of the extracts on P. falciparum. Concentrations inhibiting 50% of the parasite growth (IC(50)) ranged from 2.34 to more than 500 microg/ml according to the plant. For the most active plants (A. cordifolia and T. glaucescens) ethanol and pentane extracts were made and tested. The IC(50) values obtained for these extracts ranged from 0.35 to 43.40 microg/ml. The stage specificity of the ethanol extracts of A. cordifolia and T. glaucescens and pentane extract of T. glaucescens on the parasite erythrocytic cycle were determined. The ethanol extract of T. glaucescens showed its highest activity at the transition from the trophozoite to the schizont stages. Cytotoxicity was estimated on human fibroblasts (HeLa) cells and a cytotoxicity/antiplasmodial index was calculated, it ranged between 5 and 21, and the best antiplasmodial extract (T. glaucescens ethanol extract) had the higher index (>20).

Volatile Components of Annona muricata L.

ABSTRACT GC/MS analysis of the leaf, peel and fruit pulp oils of Annona muricata L. showed the presence of 68 compounds of which 59 were identified. The main components of the leaf oil were β-caryophyllene (31.4%) and other sesquiterpenes, while the fruit oil contained essentially aliphatic acids and esters, in particular, methyl (E)-2-hexenoate (39.8%).

A Chemical, Bacteriological, Toxicological and Clinical Study of the Essential Oil of Lippia multiflora Mold. (Verbenaceae)

ABSTRACT The leaf oil of Lippia multiflora was examined by GC and GC/MS and found to contain (Z)-tagetone (11.3%) and (E)-tagetone (30.2%) as major constituents. It was found to be highly active against isolated microorangisms of the buccal flora. A mouthwash prepared at a dilution of 1/500 of the essential oil showed the same activity as the oil. Tests for toxicity proved negative. The results obtained thus far reveal a particularly promising potential for the large scale use of L. multiflora.

Volatile Composition of Fourteen Species of Fresh Wild Mushrooms (Boletales)

Abstract Fourty-five volatile substances of fourteen species of fresh wild mushrooms (Boletus aereus, Boletus calopus, Chroogomphus rutilus, Gomphidius glutinosus, Leccinum aurantiacum, Leccinum lepidum, Leccinum pulchrum, Leccinum querci-num, Leccinum versipelle, Paxillus atrotomentosus, Suillus bovinus, Suillus collinitus, Suillus granulatus, Suillus variegatus) have been identified by GC/MS. The main components of the fruit bodies were 1-octen-3-ol, (E)-2-octenol, 1-octen-3-one, octanol, 3-octanone, 3-octanol, N(2-phenylethyl)acetamide, benzaldehyde, limonene, geranyl acetone, farnesyl acetone and (E,E)-farnesol. Camphene and germacrene D were identified for the first time in mushrooms.

In vitro Cytotoxic Activity of Three Essential Oils from Salvia Species

Abstract Essential oils of Salvia officinalis L., S. sclarea L. and S. lavandulifolia Vahl. (Lamiaceae) prepared by hydrodistillation were characterized by GC/MS. The oils were found to possess the following major components: S. officinalis: 1,8-cineole (11.7%), α-thujone (65.5%) and β-thujone (15.4%); S. sclarea: linalool (10.7%) and linalyl acetate (81.1%) and S. lavandulifolia: 1,8-cineole (25.5%), camphor (39.0%) and linalyl acetate (10.2%). These oils were tested for cytotoxic activities on cultures of different human tumor cell lines. Cytotoxic activity was compared to that of the anticancer agent doxorubicin. The oils of S. officinalis and S. lavandulifolia were 100 to 1000 times less active than doxorubicin on all the cell lines. S. sclarea oil showed a strong in vitro activity against cell suspensions in the same range as doxorubicin and was 100 times less active on attached cell cultures.

The anise-like odor of Clitocybe odora, Lentinellus cochleatus and Agaricus essettei

The fruiting bodies of fresh and wild Clitocybe odora, Lentinellus cochleatus and Agaricus essettei were investigated for volatile compounds by gas chromatography-mass spectrometry analysis using hydro-distillation and solvent extraction techniques. The three mushroom species are well known to possess anise odors. The main volatile compounds of the three species were aromatic derivatives. Anise fragrance was due either to a single impact aroma compound, or to mixtures of volatile constituents. p-Anisaldehyde was identified as the key odorous component responsible for the pure anise fragrance of C. odora. p-Anisaldehyde, methyl p-anisate, methyl (Z)-p-methoxycinnamate and methyl (E)-p-methoxycinnamate were responsible for the aniseed smell of L. cochleatus. Benzaldehyde and benzyl alcohol may contribute to the anise-like odor of A. essettei.