Antibacterial activity of Barringtonia racemosa

The antibacterial activity of the ethanol extract of Barringtonia racemosa roots, its chloroform soluble fraction and, a there from an isolated clerodane diterpenoid is reported.     

Antibacterial activity of Syzygium cumini and Syzygium travancoricum leaf essential oils

The leaf essential oils of Syzygium cumini and Syzygium travancoricum were tested for their antibacterial property. The activity of S. cumini essential oil was found to be good, while that of S. travancoricum was moderate.     

Antibacterial activity of Salvia tomentosa essential oil.

The essential oil of Salvia tomentosa aerial parts, consisting of 1,8-cineol (17%), beta-caryophyllene (11%), cyclofenchene (10%) and delta-cadinene (6%), was screened for its antimicrobial activity. The essential oil remarkably inhibited the growth of tested Gram-positive and Gram-negative bacteria except for Pseudomonas aeruginosa.     

Antibacterial properties of Thymus pubescens and Thymus serpyllum essential oils

Antibacterial properties of essential oils of Thymus pubescens and Thymus serpyllum collected at pre and flowering stages were studied. The oils were found to possess bactericidal activities.     

Antibacterial properties of essential oils from Thai medicinal plants

By using disc diffusion assay, the antimicrobial activity of 32 essential oil samples extracted from local plants or plants cultivated in Thailand was evaluated against zoonotic enteropathogens including Salmonella spp., Escherichai coli O157, Campylobacter jejunii and Clostridium perferingens which are important for broiler export. Out of the essential oil tested, only the essential oil of Zingiber cassumuna, Cinnamomum bejolghota, Mentha arvensis var. piperacens, Cymbopogon citratus and Ocimum basilicum var. citratum showed promising antibacterial activity against the bacteria tested.     

First report on Meloidogyne chitwoodi hatching inhibition activity of essential oils and essential oils fractions

The Columbia root-knot nematode (CRKN), Meloidogyne chitwoodi, is an EPPO A2 type quarantine pest since 1998. This nematode causes severe damage in economically important crops such as potato and tomato, making agricultural products unacceptable for the fresh market and food processing. Commonly used nematicidal synthetic chemicals are often environmentally unsafe. Essential oils (EOs) may constitute safer alternatives against RKN. EOs, isolated from 56 plant samples, were tested against CRKN hatching, in direct contact bioassays. Some of the most successful EOs were fractionated and the hydrocarbon molecules (HM) and oxygen-containing molecules (OCM) fractions tested separately. 24 EOs displayed very strong hatching inhibitions (≥90 %) at 2 µL mL^?1 and were further tested at lower concentrations. Dysphaniaambrosioides, Filipendula ulmaria, Ruta graveolens, Satureja montana and Thymbra capitata EOs revealed the lowest EC₅₀ values (<0.15 µL mL^?1). The main compounds of these EOs, namely 2-undecanone, ascaridol, carvacrol, isoascaridol, methyl salicylate, p-cymene and/or γ-terpinene, were putatively considered responsible for CRKN hatching inhibition. S. montana and T. capitata OCM fractions showed hatching inhibitions higher than HM fractions. The comparison of EO and corresponding fractions EC₅₀ values suggests interactions between OCM and HM fractions against CRKN hatching. These species EOs showed to be potential environmentally friendly CRKN hatching inhibitors; nonetheless, bioactivity should be considered globally, since its HM and OCM fractions may contribute, diversely, to the full anti-hatching activity.     

Antibacterial activity of the essential oil of Cymbopogon densiflorus.

The essential oil of Cymbopogon densiflorus showed a wide spectrum of activity against Gram-positive and Gram-negative bacteria.     

Antibacterial activity of Rosa damascena essential oil

The essential oil of Rosa damascena petals was evaluated for its antibacterial effects against three strains of Xanthomonas axonopodis spp. vesicatoria. The essential oil may be a potential control agent in the management of the disease caused by X.a. vesicatoria in tomato and pepper plants.     

Antibacterial activity of the essential oil from Lippia aff. gracillis

The essential oil of fresh leaves of Lippia aff. gracillis was analyzed by GC/MS and evaluated for its antibacterial effects. The results showed a moderate antibacterial activity and confirm the traditional uses of L. aff. gracillis.     

Antibacterial activity of essential oils,their blends and mixtures of their main constituents against some strains supporting livestock mastitis

Ten of the most known and used commercial essential oils (Cinnamomum zeylanicum L., Citrus bergamia Risso, Eucalyptus globulus Labill., Foeniculum vulgare Mill., Origanum majorana L., Origanum vulgare L., Rosmarinus officinalis L., Satureja montana L., Thymus vulgaris L. ct. carvacrol, Thymus vulgaris L. ct. thymol) were tested against six bacteria strains Staphylococcus aureus, Staphylococcus chromogenes, Staphylococcus sciuri, Staphylococcus warneri, Staphylococcus xylosus and Escherichia coli, responsible for mastitis in animals. The best results were achieved by S. montana, T. vulgaris ct. thymol and O. vulgare. Two binary mixtures of essential oils (EOs) were prepared of S. montana and T. vulgaris ct. thymol (ST) and of S. montana and O. vulgare (SO). The ST mixture exhibited the best inhibitory activity against all the tested bacterial strains. Two artificial mixtures of carvacrol/thymol (AB) and carvacrol/thymol/p-cymene (CD) were prepared and tested against all of the bacterial strains used. The results exhibited a general reduction of the inhibitory activity of mixture AB, although not reaching the inhibition of the ST and SO mixtures. However the mixture CD presented an apparent strong inhibition against S. aureus and S. sciuri. The EO mixtures and the mixture CD represent promising phytotherapic approaches against bacteria strains responsible for environmental mastitis.     

Antibacterial effects of commercial essential oils over locally prevalent pathogenic strains in Mexico

Locally prevalent pathogenic bacteria 189 Gram (-) and 135 Gram (+) strains, all isolated from pediatric patients severely infected, were tested in vitro against 11 essential oils from commercial origin. All the strains showed resistance to selected antibiotics. Cinnamomum verum, Origanum vulgare and Thymus vulgaris exhibited the highest and broadest antibacterial activity. Emphasis is made in the potential implications of these resources, uncommon at the clinical setting of the study, employed against non-commercial, locally pathogenic strains, being a step to submit in the ensuing period essential oils from plants used in Mexican traditional medicine.     

Two new epimeric isopavine N-oxides from Meconopsis horridula var. racemosa

Two new epimeric isopavine N-oxides, amuresinine N-oxide A (1) and B (2), were isolated from Meconopsis horridula var. racemosa. Their structures were elucidated by spectroscopic methods.     

Repellent activity of selected essential oils against Aedes aegypti

Essential oils extracted from ten plant species were screened for repellency against Aedes aegypti mosquitoes. Three oils; Zanthoxylum piperitum, Anethum graveolens and Kaempferia galanga, exerted protection against A. aegypti, with median complete-protection times of 1, 0.5 and 0.25 h, respectively. The protection times were increased significantly by incorporating 10% vanillin. The highest potential was established from Z. piperitum oil +10% vanillin (2.5 h, range=1-2.5 h). Mixtures from pairs of the effective oils possessed slight repellency that ranged from 0-0.5 h. None of the oil combinations repelled A. aegypti for longer than their constituent oil alone. With vanillin added, however, each oil mixture provided improved protection, which was approximately equal to oil on its own. GC/MS analysis revealed that the main component of Z. piperitum fruit oil was limonene (37.99%), with minor amounts of sabinene (13.30%) and beta-myrcene (7.17%). Repellent testing of stored samples of Z. piperitum fruit oil against A. aegypti demonstrated that repellent activity of those kept at -20 degrees C or 4 degrees C was present for a period of at least 3 months. Therefore, the essential oil of Z. piperitum fruit may prove useful in the development of mosquito repellents as an effective personal protection measure against mosquito bites.     

Repellent activity of five essential oils against Culex pipiens

Essential oils extracted from the seeds of anise (Pimpinella anisum), dried fruits of eucalyptus (Eucalyptus camaldulensis), dried foliage of mint (Mentha piperita) and basil (Ocimum basilicum) and fresh foliage of laurel (Laurus nobilis) were tested for their repellency against the adult females of Culex pipiens. All essential oils showed repellency in varying degrees, eucalyptus, basil and anise being the most active.     

Antibacterial activity of the essential oil from Aristolochia indica

The essential oil of Aristolochia indica, containing beta-caryophyllene and alpha-humulene as major constituents, was found to show a moderate antibacterial activity.     

Antibacterial activity of the essential oil from Ferula gummosa seed

Antibacterial activity of Ferula gummosa essential oil was studied against bacterial laboratory ATCC standards using the disk diffusion method. The results showed activity against Gram(+) bacteria and Escherichia coli. Little antibacterial activity was found against Pseudomonas aeruginosa.     

Antibacterial activity of the essential oil from Cymbopogon nervatus inflorescence

Antibacterial activity of essential oil of dried inflorescence of Cymbopogon nervatus was investigated. The essential oil remarkably inhibited the growth of tested bacteria except for Salmonella typhi. The maximum activity was against Shigella dysenteriae and Klebsiella pneumoniae.     

Insecticidal activity of some essential oils against larvae of Spodoptera littoralis

Thirty-four essential oils were tested for insecticidal activity (fumigation or topical application) against larvae Spodoptera littoralis. Twenty essential oils applied by fumigation were highly toxic to the third instar of S. littoralis larvae. Two essential oils Nepeta cataria and Thuja occidentalis were highly toxic, with LC50< or =10.0 ml/m3. Five essential oils Salvia sclarea, Thymus mastichina, Origanum majorana, Pogostemon cablin and Mentha pulegium were toxic with LC50 between 10.1 and 20.0 l ml/m3. Twenty-three essential oils were highly toxic to the third instar of S. littoralis larvae after topical application. Eight essential oils Mentha citrata, N. cataria, S. sclarea, O. vulgare, O. compactum, Melissa officinalis, T. mastichina, and Lavandula angustifolia were highly toxic with LD50 < or =0.05 microl/larvae.     

Antibacterial activity of Achillea clavennae essential oil against respiratory tract pathogens

The essential oil of Achillea clavennae was investigated for its antibacterial activity against some respiratory tract pathogens. Maximum activity was observed against Klebsiella pneumoniae and penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae. The oil also exhibited strong activity against Gram (-) Haemophilus influenzae and Pseudomonas aeruginosa. Gram (+) Streptococcus pyogenes was the most resistant to the oil.