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The essential oil (EO) of plants of the Poaceae family has diverse chemical constituents with several biological properties. But, data on the chemical constituents and toxicity are still unavailable for some species belonging to this family, such as Euclasta condylotricha Steud (Eu. condylotricha). In this study, the chemical composition of the EOs of Eu. condylotricha flowers was evaluated by gas chromatography coupled with mass spectrometry (GC-MS). The EOs larvicidal property was assessed against third instar larvae of three Anopheles gambiae laboratory strains (Kisumu, Acerkis and Kiskdr) according to the WHO standard protocol. The percentage yields of the EOs obtained from hydro distillation of Eu. condylotricha flowers varied 0.070 to 0.097%. Gas Chromatography-Mass Spectrometry (GC-MS) applied to the EOs revealed fifty-five (55) chemical constituents, representing 94.95% to 97.78% of the total essential oils. Although different chemical profiles of the dominant terpenes were observed for each sample, EOs were generally dominated by sesquiterpenoids with juvenile hormones as the major compounds. The primary compounds were juvenile hormone C16 (JH III) (35.97-48.72%), Methyl farnesoate 10,11-diol (18.56-28.73%), tau-Cadinol (18.54%), and β-Eudesmene (12.75-13.46%). Eu. condylotricha EOs showed a strong larvicidal activity with LC50 values ranging from 35.21 to 52.34 ppm after 24 hours of exposition. This study showed that Eu. Condylotricha flowers essential oils are potent sources of juvenile hormones that could be a promising tool for developing an eco-friendly malaria vector control strategy.

Cette étude porte sur la caractérisation des élevages de ruminants dans la région des plateaux au Togo. Elle a concerné 190 unités d’élevage de huit préfectures de ladite région. Chaque éleveur ciblé a été questionné afin de ressortir les caractéristiques du système d’élevage. Les enquêtes ont été effectuées au niveau des sites ciblés et sur les parcours de pâturages habituels. Les résultats ont montré que ces systèmes d’élevage sont essentiellement semi-divagants où le pâturage naturel est la principale source d’alimentation, avec rareté de complémentation alimentaire. La région dispose de ressources en eau importantes et d’un potentiel fourrager intéressant qui ne profitent pas au cheptel à cause de sa non disponibilité et sa non accessibilité. Les aspects zootechniques, génétiques et sanitaires ne sont pas respectés. Les éleveurs ne trouvent pas d’intérêt à se mettre en organisation; pourtant, à travers diverses structures, l’Etat leur assure un suivi technique permanent et de qualité. Mots clés : caractérisation, élevage, ruminants, système, pâturage.

The aerial parts essential oils of Ocimum basilicum (Lamiaceae) from Togo were steam-distilled and investigated for their percentage composition (GC and GC/MS) and in vitro antimicrobial activities. Five oil chemotypes were identified and classified as follows in line with their principal components: estragole type; linalool/estragole type; methyleugenol type; methyleugenol/t-anethole type; t-anethole type. The in vitro microbiological experiments revealed that only the methyleugenol and methyleugenol/t-anethole chemotypes were active against tested fungi and bacteria. Their minimum inhibitory concentrations (MIC) ranged from 80 to 150 µl.l-1 and from 200 to 500 µl.l-1 respectively. Likewise, on tested bacteria the MIC varied from 200 µl.l-1 to 400 µl.l-1 and from 250 to 500 µl.l-1 respectively. These findings are supportive of the potential of both basil oil chemotypes for use as active ingredients in natural antibiotic drugs.

The leaf essential oils of Cymbopogon citratus L. and Cymbopogon nardus L.(Poaceae) from Togo were steam-distilled, analyzed for percentage composition and investigated in vitro for their potential cytotoxic activity on human epidermic cell line HaCat. The percentage composition showed that the main constituents of essential oils samples were respectively geranial (45.2%), neral(32.4%) and myrcène (10.2%) for C. citratus essential oil and citronellal (35.5%), geraniol (27.9%) and citronellol (10.7%) for that of C. nardus. The in vitro cytotoxicity bioassays on human epidermic cell line HaCaT revealed that the toxicityof the essential oil from C. citratus (IC50: 150 μL.mL-1) was higher than that of the essential oil from C. nardus (IC50: 450 μL.mL-1). Pure commercial neral, geranial, and citronellal standards showed respectively the following IC50 values: 100, 250 and 300 μL.mL-1). Conversely, pure citronellol standard appeared almost non-toxic (IC50>1000 μL.mL-1), proving the major role played in synergyby neral and geranial in the overall toxicity showed by the citratus oil sample tested in this work.

The aerial parts essential oils of Ocimum basilicum (Lamiaceae) from Togo were steam-distilled and investigated for their percentage composition (GC and GC/MS) and in vitro antimicrobial activities. Five oil chemotypes were identified and classified as follows in line with their principal components: estragole type; linalool/estragole type; methyleugenol type; methyleugenol/t-anethole type; t-anethole type. The in vitro microbiological experiments revealed that only the methyleugenol and methyleugenol/t-anethole chemotypes were active against tested fungi and bacteria. Their minimum inhibitory concentrations (MIC) ranged from 80 to 150 µL/L and from 200 to 500 µL/L respectively. Likewise, on tested bacteria the MIC varied from 200 µL/L to 400 µL/L and from 250 to 500 µL/L respectively. These findings are supportive of the potential of both basil oil chemotypes for use as active ingredients in natural antibiotic drugs.

The leaf essential oils of Cymbopogon citratus L. and Cymbopogon nardus L. (Poaceae) from Togo were steam-distilled, analyzed for percentage composition and investigated in vitro for their potential cytotoxic activity on human epidermic cell line HaCat. The percentage composition showed that the main constituents of essential oils samples were respectively geranial (45.2%), neral (32.4%) and myrc¨ne (10.2%) for C. citratus essential oil and citronellal (35.5%), geraniol (27.9%) and citronellol (10.7%) for that of C. nardus. The in vitro cytotoxicity bioassays on human epidermic cell line HaCaT revealed that the toxicity of the essential oil from C.citratus (IC50: 150 µL.mL-1) was higher than that of the essential oil from C.nardus (IC50: 450 µL.mL-1). Pure commercial neral, geranial, and citronellal standards showed respectively the following IC50 values: 100, 250 and 300 µL.mL-1). Conversely, pure citronellol standard appeared almost non-toxic (IC50>1000 µL.mL-1), proving the major role played in synergy by neral and geranial in the overall toxicity showed by the citratus oil sample tested in this work.