Komla Sanda

Chemical Composition and in vitro Cytotoxic Activity of Essential Oils from Two Tropical Lamiaceae: Aeollanthus pubescens Benth. and Ocimum gratissimum L

Abstract Essential oils of Aeollanthus pubescens Benth. and Ocimum gratissimum L. (Lamiaceae) from Togo were investigated for their percentage composition and in vitro cytotoxicity. The GC and GC-MS analyses indicated that the major constituents of both essential oils were thymol, p-cymene and γ-terpinene. Testing of these volatile oils and their major constituents from commercial origin in vitro for possible cytotoxicity on the human epidermic cell line HaCat showed that the toxicity of the essential oil of A. pubescens (IC50: 1800µg.ml−1) was higher than that of the essential oil of O. gratissimum (IC50: 2400 µg.ml−1). Pure commercial thymol standard showed a cytotoxicity (IC50: 1800 µg.ml−1) identical to that of the A. pubescens essential oil. Conversely, p-cymene and γ-terpinene standards were found almost non-toxic (IC50 >3000 µg.ml−1). These findings support the assumption that the cytotoxic activities of the tested essential oils were basically due to their high level content in thymol.

Chemical Composition and In Vitro Cytotoxic Activity of Xylopia aethiopica (Dun) A. Rich. (Annonaceae) Fruit Essential Oil from Togo

Abstract Essential oil extracted (4.4% in yield) from air-dried fruits of Xylopia aethiopica harvested in Togo was investigated for percentage composition and in vitro cytotoxicity. The chemical composition of the essential oil was examined by GC and GC/MS. Thirty-five compounds were identified representing 89.9% of total oil. The major constituents were β-pinene (23.6%), α-pinene (11%), sabinene (9.8%), germacrene D (8.3%) and 1,8 cineole (8.2%). The cytotoxicity of the volatile oil was evaluated in vitro on the human epidermal cell line HaCaT. The tested sample did not show any cytotoxicity (IC50 >3000 μg.ml-1) effect at concentrations around 3000 μg.ml-1. Further testing in bioassay would probably help in validating some of medicinal uses of X. aethiopica in topical drugs and/or in cosmetics as natural products.

Chemical Composition and Insecticidal Activity of Ocimum canum Essential Oil Against Coffee Berry Borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae)

Abstract The chemical compositions of the essential oils of Ocimum canum Sims (Lamiaceae) areal part cultivated in Togo were investigated by GC-MS and tested for possible insecticidal activity against the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytinae) under laboratory. Eighteen constituents (98.5 % of the total oil) were identified in the volatile oil of O. canum leaf. The main constituents found in the oil were terpineol-4 (34.7 %), linalool (22.7 %), λ-terpinene (7.3 %), trans-thujan-4-ol (5.9 %), trans-α-bergamotene (4.9 %) and caryophyllene (4.6 %). Other components were also identified by at minor concentrations ranging from 0.12 % (Thymol) to 2.7 % (Limonene). In the insecticidal activity test, crude essential oil of O. canum emulsions of exhibited adulticidal activity against coffee berry borer and response was being dose-related. The LD50 were 320 ppm for O. canum essential oil and 450 ppm for endosulfan and the conventional insecticide used as standard, respectively. The results indicate that the O. canum essential oil has a potential insecticidal activity and can be used as active ingredient in natural and sustainable pesticide within an Integrated Pest Management approach to combat the coffee berry borer.

Chemical Composition and Insecticidal Activity of Aeollanthus pubescens Essential Oil Against Coffee Berry Borer (Hypothenemus hampei Ferrari) (Coleoptera: Scolytidae)

Abstract Essential oil extracted from aerial parts of Aeollanthus pubescens was analysed for its chemical composition and investigated for possible insecticidal activity against Hypothenemus hampei (Ferrari), the major pest of coffee throughout the world. The GC and GC-MS analyses indicated that linalool (56.4 %) and fenchone (28.6 %) were the main components of the tested A. pubescens oil sample. Emulsions of crude essential oil of A. pubescens exhibited adulticidal activity against coffee berry borer and response was being dose-related. The LD50 were respectively 220 ppm for A. pubescens essential oil and 450 ppm for endosulfan, the conventional insecticide used as standard. These preliminary findings indicate that the tested volatile oil have a potential insecticidal activity and can be used as active ingredient in natural and sustainable pesticide within an Integrated Pest Management approach to combat coffee berry borer.

Capacités morphogénétiques in vitro, performance au champ et production d'huiles essentielles chez Ocimum gratissimum L.

Abstract Morphogenetic capacities of Ocimum gratissimum were revealed in vitro from nodal segment—derived shoots cultivated with α-naphtalene acetic acid (NAA, 0.54 or 5.37 μM), or indolebutyric acid (IBA, 2.45 μM), or 6-benzylamino- purine (BAP, 0.44 or 4.44 μM) or kinetin (Kin, 0.46 or 4.65 μM). NAA or IBA decreased caulogenesis and slowed down rooting. Both auxins improve growth of the shoots by elongation of the inter-nodes. BAP (4.44 μM) or Kin (4.65 μM) led to bushing shoots. Four months old plantlets (10%) were successfully acclimatized in greenhouse, before being cultured in field. Essential oils were analyzed by simple gas chromatography and coupled with the mass spectrometry. Essential oil efficiencies (EO %) were found to be superior to these of the mother plant and thymol, p-cymene, γ-terpinene and ß-myrcene could be mainly identified in the harvested plants.

Chemical Composition and Cytotoxic Activity of Essential Oil of Chromolaena odorata L. Growing in Togo

Abstract The leaf essential oil of Chromolaena odorata L. (Asteraceae) harvested in Togo were steam-distilled and investigated for chemical composition (GC and GC-MS) and in vitro potential cytotoxic activity on human epidermic cell line HaCat. The chemical composition showed that the main constituents of essential oil sample were respectively β-caryophyllene (25.2 %), germacrene D (18.8 %), and linalool (7.9 %). The in vitro cytotoxicity bioassays on human cell line HaCaT did not revealed any toxicity of C. odorata essential oil up to 3000 μL.mL−1. Pure commercial β-caryophyllene and germacrene D standards appeared almost non-toxic (IC50 >3000 μL.mL−1), proving the major role played by the major components in the overall cell viability showed by the C. odorata oil sample tested in this work.

Antibacterial Activities of Coleus Aromaticus Benth (Lamiaceae) Essential Oil against Oral Pathogens

Abstract Leaf essential oil of Coleus aromaticus (Lamiaceae) from Cambodia was steam-distilled and investigated for its percentage composition and antibacterial activity against ffteen oral microflora pathogen strains. The volatile oil sample investigated in this work contained mainly thymol (57.4%), carvacrol (13.5%), γ-terpinene (5.6%), and p-cymene (5.2%). The in vitro antibacterial experiments revealed that on tested bacteria the minimum inhibitory concentration (MIC) ranged 40–80 µL/Land the minimum bactericidal concentration (MBC) 80–150 µL/L. These findings support the idea that the C. aromaticus essential oil sample tested here could be suitable for use as a natural active ingredient in natural and low-cost drugs against oral microflora.

Chemical Composition of Hyptis pectinata L., H. lanceolata Poit , H. suaveolens (L) Poit and H. spicigera Lam. Essential Oils from Togo

Abstract Essential oils of Hyptis pectinata L. (leaves and flowers), H. lanceolata Poit,(leaves), H. suaveolens (L) Poit (leaves and flowers) and H. spicigera Lan. (leaves) harvested in Togo were obtained by hydrodistillation and analysed by GC and GC-MS. The main constituents of the essential oils were respectively caryophylene oxide (32.7 %), humulene epoxide (9.3 %) for Hyptis pectinata and germacrene D (27.8 %), β-caryophyllene (12.6 %) and β-elemene (9.5 %) for H. lanceolata oil sample. In the H. spicigera essential oil sample β-caryophyllene (33.8 %), α-bergamotene (11.3 %) and α-caryophyllene (7.4 %) were found as the major constituents. In the H. suaveolens essential oil, sabinene (28.0 %) and β-caryophyllene (25.8 %) were mentioned as major constituents of the essential oil.

Investigation of Insecticidal Activity of Blend of Essential Oil of Cymbopogon schoenanthus and neem oil on Plutella xylostella (Lepidoptera: Plutellidae)

Abstract Plant and plant derived materials appear nowadays as a safe alternative to conventional pesticides to fight against crop pests. For this purpose, activity of blend (1:1 weight/weight) of Cymbopogon schoenanthus essential oil and neem (Azadirachta indica) seed oil on diamondback moth (Plutella xylostella) through contact and feeding methods were investigated and compared to each individual botanical. In the contact method, the combination of Cymbopogon schoenanthus/Azadirachta indica (LC50 = 23.3 mg/ml) oils exhibited medium activity showing higher toxicity than neem oil (58.39 mg/ml) and lower toxicity than Cymbopogon schcoenanthus essential oil (LC50 = 12.08 mg/ml). In feeding method, the toxicity resulted from the blend of Cymbopogon schoenanthus/Azadirachta indica (LC50 = 47.02) was slightly higher than both considered separately (LC50 = 52.39 and 53.63 for Cymbopogon schcoenanthus and neem respectively). Neem oil and the blend of Cymbopogon schoenanthus /neem exhibit strong antifeedance effect and inhibition of adult emergence of Plutella xylostella. The interaction between the mixture of Cymbopogon schoenanthus/ neem was additive resulting in increasing of insecticidal spectrum and could be used as an alternative to chemical pesticide in cabbage protection against Plutella xylostella.

Etude comparée de l’efficacité de la cyperméthrine et deux bioinsecticides, Beauveria bassiana et suneem contre l’altise du gombo, Podagrica spp (Coleoptera: Chrysomelidae)

Parmi les ravageurs du gombo, Abelmoschus Spp L., les altises, Podagrica Spp (Coleoptera: Chrysomelidae), causent d’importants dommages a la culture. Les fortes infestations de l’insecte reduisent les activites photosynthetiques de la plante, entrainant des pertes elevees de rendement. La presente etude vise a comparer l’effet de deux bioinsecticides, Suneem 1% EC, 10 g/l d’azadirachine (20%), Beauveria bassiana (1 x1011 spores/ha) et le cypermethrine 50 EC (1 l / ha), un insecticide de synthese, pour le controle de Podagrica Spp, en conditions de champ. Deux applications des differentes formulations ont ete faites a intervalle de 6 jours sur la partie aerienne des plantes. Les resultats ont montre que la cypermethrine a cause la plus forte reduction de la densite de population des altises (89,56 ± 0,76), suivi de Suneem (81,24 ± 2,40) et du B. bassiana (64,90 ± 3,07). De meme le pourcentage des feuilles attaquees et le pourcentage de surface foliaire endommagee par l’insecte ont ete significativement affectes par les traitements. Il ressort de cette etude que B. Bassiana et le Suneem, peuvent etre utilises pour lutter efficacement contre les populations d’altises de gombo, Podagrica Spp en condition de champ. Mots cles : Bioinsecticide, champignon entomopathogene, altise du gombo, reduction de la densite.