Antimicrobial activity of some Salvia species essential oils from Iran

The aerial parts of Salvia multicaulis, S. sclarea and S. verticillata were collected at full flowering stage. The essential oils were isolated by hydrodistillation and analyzed by combination of capillary GC and GC-MS. The in vitro antimicrobial activity of the essential oils were studied against eight Gram-positive and Gram-negative bacteria (Bacillus subtilis, Bacillus pumulis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and three fungi (Candida albicans, Saccharomyces cerevisiae and Aspergillus niger). The results of antibacterial activity tests of the essential oils according to the disc diffusion method and MIC values indicated that all the samples have moderate to high inhibitory activity against the tested bacteria except for P. aeruginosa which was totally resistant. In contrast to antibacterial activity, the oils exhibited no or slight antifungal property, in which only the oil of S. multicaulis showed weak activity against two tested yeasts, C. albicans and S. cerevisiae.     

Antifungal activity of the essential oils from some species of the genus Pinus

The chemical composition of the essential oils from the needles of Pinus ponderosa (north american pine), P. resinosa (red pine) and P. strobus (eastern white pine) has been determined by GC/MS (FID). The essential oils from P. resinosa and P. ponderosa in comparison to P. strobus have been characterized by the higher content of beta-pinene (42.4%, 45.7% and 7.9% respectively). On the other hand, a-pinene (17.7%) and germacrene D (12.2%) were dominant compounds of P strobus. Moreover the essential oil from P. resinosa was more rich in myrcene-15.9%. Estragole and delta-3-carene, each one in amount ca 8% were identified only in P. ponderosa. The content of essential oils in the needles slightly varied--0.65%--P. resinosa, 0.4%--P strobus, 0.3%--P. ponderosa. The antifungal activity has been investigated towards Fusarium culmorum, F solani and F. poae. The strongest activity was observed for the essential oil from P. ponderosa, which fully inhibited the growth of fungi at the following concentrations--F. culmorum, F. solani at 2% and F. poae at 5%.     

Antimicrobial activity of Amazonian oils against Paenibacillus species

The Gram-positive, spore-forming bacterium Paenibacillus larvae is the primary bacterial pathogen of honeybee brood and the causative agent of American foulbrood disease (AFB). One of the feasible alternative treatments being used for their control of this disease is essential oils. In this study in vitro antimicrobial activity of Andiroba and Copaíba essential oils against Paenibacillus species, including P. larvae was evaluated. Minimal inhibitory concentration (MIC) in Mueller-Hinton broth by the microdilution method was assessed. Andiroba registered MIC values of 1.56-25%, while the MICs values obtained for Copaíba oil were of 1.56-12.5%. In order to determine the time-response effect of essential oils on P. larvae, this microorganism was exposed to the oils for up to 48 h. After 24 h treatment with Andiroba oil and after 48 h treatment with Copaíba oil no viable cells of P. larvae ATCC 9545 were observed. The possible toxic effect of essential oils were assessed by the spraying application method of the same concentrations of MICs. Bee mortality was evident only in treatment with Andiroba oil and the Copaíba oil shows no toxic effects after 10 days of observation. Taking together ours results showed for the first time that these oils presented a high activity against Paenibacillus species showing that Copaíba oil may be a candidate for the treatment or prevention of AFB.     

Antifungal activity of essential oils of Croton species from the Brazilian Caatinga biome

Aims: To find new antifungal agents among essential oils from Brazilian Croton species. Methods and Results: Plant leaves were steam distilled and the obtained essential oils were analyzed by gas chromatography/mass spectroscopy. The main constituents were estragole and anethole for Croton zehntneri, methyl-eugenol and bicyclogermacrene for Croton nepetaefolius and spathulenol and bicyclogermacrene for Croton argyrophylloides. The antifungal activity of essential oils was evaluated against Candida albicans, Candida tropicalis and Microsporum canis by the agar-well diffusion method and the minimum inhibitory concentration (MIC) by the broth microdilution method. Essential oils of Croton species demonstrated better activity against M. canis. Among the three plants C. argyrophylloides showed the best results, with MIC ranging from 9 to 19 μg ml⁻¹. The acute administration of the essential oil up to 3 g kg⁻¹ by the oral route to mice was devoid of overt toxicity. Conclusions: The studied essential oils are active in vitro against the dermatophyte M. canis and present relative lack of acute toxicity in vivo. Significance and Impact of the Study: Because of its antifungal activity and low toxicity, the essential oils of studied Croton species are promising sources for new phytotherapeutic agents to treat dermatophytosis.     

Antimicrobial activity of essential oils isolated from Portuguese endemic species of Thymus

AIMS: Thymus species are wild species mostly found in the arid lands of Portugal. Possible antimicrobial properties of Thymus essential oils have been investigated. The chemical composition of the essential oils and the antimicrobial activity of Thymus mastichina (L) L. subsp. mastichina, T. camphoratus and T. lotocephalus from different regions of Portugal were analysed. METHODS AND RESULTS: Hydrodistillation was used to isolate the essential oils and the chemical analyses were performed by gas chromatography (GC) and GC coupled to mass spectrometry. The antimicrobial activity was tested by the disc agar diffusion technique against Candida albicans, Escherichia coli, Listeria monocytogenes, Proteus mirabilis, Salmonella spp. and Staphylococcus aureus. Pure linalool, 1,8-cineole and a mixture (1 : 1) of these compounds were included. Linalool, 1,8-cineole or linalool/1,8-cineole and linalool/1,8-cineole/linalyl acetate were the major components of the essential oils, depending on the species or sampling place. The essential oils isolated from the Thymus species studied demonstrated antimicrobial activity but the micro-organisms tested had significantly different sensitivities. CONCLUSIONS: The antimicrobial activity of essential oils may be related to more than one component. SIGNIFICANCE AND IMPACT OF THE STUDY: Portuguese endemic species of Thymus can be used for essential oil production for food spoilage control, cosmetics and pharmaceutical use. Further studies will be required to elucidate the cell targets of the essential oil components.     

Essential oils of four Myrtaceae species from the Brazilian southeast

The essential oils of the leaves of Eugenia acutata, Eugenia candolleana, Eugenia copacabanensis and Myrcia splendens (Myrtaceae) from Brazil’s southeastern Atlantic Forest were obtained by hydrodistillation and analyzed by GC–MS. Oxygenated sesquiterpenes were predominant in E. copacabanensis (54.3%) and E. candolleana (50.9%) whilst hydrocarbon species predominated in E. acutata (83.4%) and M. splendens (94.5%). trans-Caryophyllene was the most abundant component in E. acutata. Isomers of guaiol and cadinol alcohols, followed by δ-elemene and viridiflorene, were the major components of the essential oil of the leaves of E. candolleana. Hydrocarbons and alcohols of the cadinane-type predominated in E. copacabanensis the most abundant being epi-cubenol (14%). M. splendens had 80% α-bisabolene in the leaf oil along with <5% β-farnesene. Additionally, E. copacabanensis exhibited 13.7% monoterpenes. Whereas the bisabolene-rich M. splendens oil is highly similar to that of other Myrcia species reported elsewhere, the Eugenia species oils corroborated the complex array and differing abundances of terpene classes within this genus. This study generated data which may provide further comprehension of the phylogenetic relationships between Myrtaceae genera and species.     

Biosynthetic activity of cultures of different species of the genus Actinomadura

The ability to synthesize antibiotics and exoproteases was studied in 13 species belonging to the Actinomadura genus. The antibiotic and proteolytic activities were found only in A. fulvescens INA-3321 and A. citrea INA-1849. Glycerol was shown to be the best carbon source for the growth and biosynthetic activity of A. fulvescens. A. citrea had a wider spectrum of carbon sources used for the growth and a higher proteolytic and antibiotic activity. A. citrea exerted the maximal biosynthetic activity and the best growth in a medium with starch and xylose. The effect of different nitrogen sources on the growth and biosynthetic activity of A. citrea was also studied.     

Hypertensive factor: calcium stimulatory activity obtained from different tissues and animal species

It was recently shown that a peptide (hypertensive factor, HF) isolated from erythrocyte hemolysates from spontaneously hypertensive rats induced a prolonged elevation of blood pressure in normotensive rats. In addition, the peptide produced a marked stimulation of the in vitro uptake of lanthanum-resistant calcium by the aortae and enhanced the contractile response of aortic rings to constrictor agents. The present report describes findings of calcium stimulatory activity, enhancement of contractile function, or pressor activity in extracts of homogenates from several tissues of the rat and from erythrocyte hemolysates of several mammalian species. Significant stimulation of calcium uptake in aortic rings was obtained with preparations from rat brain, liver, and kidney. The activity per weight of tissue was similar for brain and kidney (approximately 2 units/g), while liver exhibited somewhat higher concentrations (4 units/g). The diffusate of cardiac tissue did not significantly alter in vitro calcium uptake by aortae. The injection of the cardiac and liver diffusates into normotensive Wistar-Kyoto rats produced slight (10 Torr) (1 Torr = 133.3Pa) and moderate (25 Torr) elevations of blood pressure, respectively. Finally, a peptide purified from homogenates of rat brain by the protocol developed for the purification of HF from erythrocytes was shown to significantly enhance the contractile response of aortic rings to K+ and norepinephrine. Diffusates of erythrocytes from the rat, rabbit, dog, and guinea pig each caused a significant stimulation of calcium uptake and contained approximately the same level of activity (500 units/L of whole blood). Diffusates prepared from outdated human erythrocytes had no significant effect on calcium uptake, whereas those of freshly drawn samples exhibited high levels of activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antimicrobial activity of some Satureja essential oils

The genus Satureja is represented by fifteen species of which five are endemic and Satureja pilosa and S. icarica have recently been found as new records for Turkey. Aerial parts of the Satureja pilosa, S. icarica, S. boissieri and S. coerulea collected from different localities in Turkey were subjected to hydrodistillation to yield essential oils which were subsequently analysed by GC and GC/MS. The main constituents of the oils were identified, and both antibacterial and antifungal bioassays were applied. Carvacrol (59.2%, 44.8%, 42.1%) was the main component in the oils of S. icarica, S. boissieri and S. pilosa, respectively. The oil of S. coerulea contained beta-caryophyllene (10.6%) and caryophyllene oxide (8.0%) as main constituents.     

Antimicrobial agents from plants: antibacterial activity of plant volatile oils

The volatile oils of black pepper [Piper nigrum L. (Piperaceae)], clove [Syzygium aromaticum (L.) Merr. & Perry (Myrtaceae)], geranium [Pelargonium graveolens L'Herit (Geraniaceae)], nutmeg [Myristica fragrans Houtt. (Myristicaceae), oregano [Origanum vulgare ssp. hirtum (Link) Letsw. (Lamiaceae)] and thyme [Thymus vulgaris L. (Lamiaceae)] were assessed for antibacterial activity against 25 different genera of bacteria. These included animal and plant pathogens, food poisoning and spoilage bacteria. The volatile oils exhibited considerable inhibitory effects against all the organisms under test while their major components demonstrated various degrees of growth inhibition.     

Larvicidal activity of essential oils from Brazilian plants against Aedes aegypti L

Aedes aegypti L. is the major vector of dengue fever, an endemic disease in Brazil. In an effort to find effective and affordable ways to control this mosquito, the larvicidal activities of essential oils from nine plants widely found in the Northeast of Brazil were analyzed by measurement of their LC50. The essential oils were extracted by steam distillation and their chemical composition determined by GL-chromatography coupled to mass spectroscopy. The essential oils from Cymbopogon citratus and Lippia sidoides, reported in the literature to have larvicidal properties against A. aegypti, were used for activity comparison. The results show that Ocimum americanum and Ocimum gratissimum have LC50 of 67 ppm and 60 ppm respectively, compared to 63 ppm for L. sidoides and 69 ppm for C. citratus. These results suggest a potential utilization of the essential oil of these two Ocimum species for the control of A. aegypti.     

Antimicrobial activity of aStreptomyces species isolated from Nsukka soil

An antibiotic-producing actinomycete was isolated from Nigerian soil and assigned to the genusStreptomyces. The antibiotic had antimicrobial activity on solid agar against both Gram-positive and Gram-negative bacteria as well as fungi.

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Résumé On a isolé un actinomycète producteur d'antibiotique d'un sol Nigérian et on lui a assigné le genreStreptomyces. L'antibiotique avait une activité antimicrobienne sur agar solide tant contre les bactéries gram-positives et les bactéries Gram-négatives que les fungi.

     

Antimicrobial activity and chemical investigation of Brazilian Drosera

The antimicrobial activity of three different extracts (hexanic, ethyl acetate, methanol) obtained from Brazilian Drosera species (D. communis, D. montana var. montana, D. brevifolia, D. villosa var. graomogolensis, D. villosa var. villosa, Drosera sp. 1, and Drosera sp. 2 ) were tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecium (ATCC23212), Pseudomonas aeruginosa (ATCC27853), Escherichia coli (ATCC11229), Salmonella choleraesuis (ATCC10708), Klebsiella pneumoniae (ATCC13883), and Candida albicans (a human isolate). Better antimicrobial activity was observed with D. communis and D. montana var. montana ethyl acetate extracts. Phytochemical analyses from D. communis, D. montana var. montana and D. brevifolia yielded 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); long chain aliphatic hydrocarbons were isolated from D. communis and from D. villosa var. villosa, a mixture of long chain aliphatic alcohols and carboxylic acids, was isolated from D. communis and 3b-O-acetylaleuritolic acid from D. villosa var. villosa.     

Antimicrobial activity studies on a trypsin-chymotrypsin protease inhibitor obtained from potato

A 5.6 kDa trypsin-chymotrypsin protease inhibitor was isolated from the tubers of the potato (Solanum tuberosum L cv. Gogu) by extraction of the water-soluble fraction, dialysis, ultrafiltration, and C18 reversed-phase high performance liquid chromatography. This inhibitor, which we named potamin-1 (PT-1), was thermostable and possessed antimicrobial activity but lacked hemolytic activity. PT-1 strongly inhibited pathogenic microbial strains, including Candida albicans, Rhizoctonia solani, and Clavibacter michiganense subsp. michiganinse. Automated Edman degradation showed that the N-terminal sequence of PT-1 was NH2-DICTCCAGTKGCNTTSANGAFICEGQSDPKKPKACPLNCDPHIAYA-. The sequence had 62% homology with a serine protease inhibitor belonging to the Kunitz family, and the peptide inhibited chymotrypsin, trypsin, and papain. This protease inhibitor, PT-1, was composed of polypeptide chains joined by disulfide bridge(s). Reduced PT-1 almost completely lost its activity against fungi and proteases indicating that disulfide bridge is essential for its protease inhibitory and antifungal activity. These results suggest that PT-1 is an excellent candidate as a lead compound for the development of novel oral or other anti-infective agents.     

Antimicrobial activity of essential oils against Helicobacter pylori

Background. Helicobacter pylori is an important pathogen responsible for gastroduodenal diseases in humans. Although the eradication of H. pylori using antibiotics often improves gastroduodenal diseases, resistance to the antibiotics is emerging. Materials and Methods. The antimicrobial effect of essential oils and the development of resistance to the essential oils were evaluated in vitro and in vivo. Results. Thirteen essential oils used in this study completely inhibited the growth of H. pylori in vitro at a concentration of 0.1% (v/v). Cymbopogon citratus (lemongrass) and Lippia citriodora (lemon verbena) were bactericidal against H. pylori at 0.01% at pH 4.0 and 5.0. Resistance to lemongrass did not develop even after 10 sequential passages, whereas resistance to clarithromycin developed under the same conditions. In in vivo studies, the density of H. pylori in the stomach of mice treated with lemongrass was significantly reduced compared with untreated mice. Conclusions. These results demonstrate that the essential oils are bactericidal against H. pylori without the development of acquired resistance, suggesting that essential oils may have potential as new and safe agents for inclusion in anti‐H. pylori regimens.     

Chromatographic profiles and antimicrobial activity of the essential oils obtained from some species and cultivars of the Mentheae tribe (Lamiaceae)

The present study was focused on the chemical composition and antimicrobial activity of the essential oils (EsO) obtained from five Lamiaceae representatives grown in the south of Ukraine. Among them are Salvia sclarea L., Monarda didyma (cultivar ‘Cambridge Scarlet’), Thymus pulegioides (cultivar ‘2/6-07’), Thymus vulgaris (cultivar ‘Jalos’), and Thymus serpyllum L. The component analysis of the EsO was carried out by gas chromatography method coupled with mass spectrometry (GC–MS). The antimicrobial properties of the EsO were determined using the agar diffusion test against widespread pathogenic bacterial strains (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Streptococcus pyogenes) and opportunistic yeast Candida albicans. The EsO of Thymus serpyllum and Thymus vulgaris (cultivar ‘Jalos’) displayed noteworthy antibacterial properties against a wide spectrum of the microorganisms. These antimicrobial properties could be attributed to the high content of aromatic monoterpenoid thymol (52.56% and 47.33%, respectively). The EsO of Salvia sclarea with the dominance of linalyl acetate (45.51%) and linalool (38.98%) as well as Thymus pulegioides (cultivar ‘2/6-07’) containing α-citral (27.10%) and β-citral (17.11%) demonstrated the strongest antimicrobial effects on typical and clinical strains of Staphylococcus aureus with the inhibition zones in the range of 24.0–31.0 mm. The Salvia sclarea EsO demonstrated the most significant effect against clinical strains of Candida albicans. In conclusion, the present study revealed the chemical composition of five Lamiaceae species and cultivars grown in the south of Ukraine and considerable antimicrobial activity of the tested EsO, especially against the typical and clinical strains of Staphylococcus aureus and Candida albicans. The obtained results could be perspective for applying in the pharmaceutical industry and for the conservation of food and cosmetic products.     

A new species of the Brazilian genus Chresta (Asteraceae, Vernonieae) from Bahia

A new species of the genus Chresta Vell. ex DC. (Vernonieae, Asteraceae) from the Brazilian state of Bahia is described and illustrated. The new species resembles Chresta pinnatifida (Philipson) H.Rob. but differs in having solitary glomerules, leaf bases clasping the stem and 35–40 capitula per glomerule. It can be distinguished from Chresta harleyii and Chresta martii , the other two species of the genus with pinnately lobed leaves, by the type of pubescence, leaf blade bases and florets number. In addition, a key to distinguish all the species of the genus is presented. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 587–590.     

Antimicrobial activity in vitro of plumbagin isolated from Plumbago species

Plumbagin is a naturally occurring naphthoquinone isolated from roots of Plumbago scandens. The plant was collected at the Campus of Funda??o Oswaldo Cruz, Rio de Janeiro, Brazil. P. scandens is used as a traditional medicine for the treatment of several diseases. The antimicrobial activity of plumbagin was evaluated using the macrodilution method. The compound exhibited relatively specific activity against bacteria and yeast. The minimum inhibitory concentration test showed the growth inhibiton of Staphylococcus aureus at a concentration of 1.56 g/ml and of Candida albicans at a concentration of 0.78 g/ml. These results suggest the naphthoquinone plumbagin as a promising antimicrobial agent.     

A new species of the spider genus Baalzebub (Araneae,Theridiosomatidae) from Brazilian caves

A new species of the spider genus Baalzebub Coddington from Brazil, B. acutum sp. nov., is described and illustrated based on 95 specimens collected from caves around the Iron Quadrangle in the state of Minas Gerais. This species is recognized by male palpal bulb with strong and large conductor covering almost entire embolus, and epigyne of females with long and tapered scape, which extends towards the spinners. Baalzebub acutum sp. nov. is the second species recorded from Brazil, the first for Brazilian caves, bringing the total number of species in the genus to seven in the world.