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Study of the Bacillus flora of Nigerian spices.

Bacteriological examination of 230 samples of five different unprocessed spices (aligator pepper, red pepper, black pepper, thyme and curry powder) collected randomly from Port Harcourt main markets revealed that the spices were highly contaminated, with bacterial counts ranging from 1.8 x 10(4) to 1.1 x 10(8) per gram. Bacillus cereus was isolated in high numbers in the majority of the 230 samples examined. It was also observed that other Bacillus spp. including B. subtilis, B. polymyxa and B. coagulans occurred in significant numbers.

Bacillus↗

Plants used in phytotherapy, cosmetics and dyeing in the Pramanda district (Epirus, North-West Greece).

Thirty plants used in phytotherapy, cosmetics and dyeing in the Pramanda district (North-West Greece) are reported. For many plants (myrtle, phlomis, daphne, etc.) the uses are localized and not noted for other phytotherapies; some uses coincide with those existing in other zones of the Mediterranean (mint, thyme, red juniper, Hypericum, etc.). The plants used are the most common and most easily found in this area.

Coloring Agents↗

Spectrophotometric analysis of irradiated spices.

Seven different spices (thyme, cinnamon, coriander, caraway, pimento, paprika, black pepper) were treated by gamma radiation at an absorbed dose of 10 kGy, and the effect on chemical quality was determined. The effects of this dose were assessed by spectrophotometric analysis of some water-soluble constituents of spices (carbohydrates; carbonyl compounds) and on the content of water-insoluble steam-volatile oils. The colour of paprika and the content of piperine in pepper held in different packaging materials were measured in unirradiated and irradiated samples as a function of storage time. In all cases irradiation does not bring about any distinct qualitative or quantitative chemical changes based on spectrophotometric analysis of spice extracts.

Condiments↗

Dogs acquire food preferences from interacting with recently fed conspecifics.

Social transmission of food preferences has been documented in many species including humans, rodents, and birds. In the current experiment, 12 pairs of domestic dogs (Canis familiaris) were utilized. Within each pair, one dog (the demonstrator) was fed dry dog food flavored with either basil or thyme. The second dog (the observer) interacted with one demonstrator for 10 min before being given an equal amount of both flavored foods. Observers exhibited a significant preference for the flavored diet consumed by their demonstrators, indicating that dogs, like rats, prefer foods smelled on a conspecific's breath.

Animals↗

Solvent-free microwave extraction of essential oil from aromatic herbs: comparison with conventional hydro-distillation.

Solvent-free microwave extraction (SFME) is a combination of microwave heating and dry distillation, performed at atmospheric pressure without added any solvent or water. Isolation and concentration of volatile compounds are performed by a single stage. SFME has been compared with a conventional technique, hydro-distillation (HD), for the extraction of essential oil from three aromatic herbs: basil (Ocimum basilicum L.), garden mint (Mentha crispa L.), and thyme (Thymus vulgaris L.). The essential oils extracted by SFME for 30min were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained by conventional hydro-distillation for 4.5 h. The SFME method yields an essential oil with higher amounts of more valuable oxygenated compounds, and allows substantial savings of costs, in terms of time, energy and plant material. SFME is a green technology and appears as a good alternative for the extraction of essential oils from aromatic plants.

Costs and Cost Analysis↗

Evaluation of NO-suppressing activity of several Mediterranean culinary spices.

Excess nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is implicated in the development of a number of diseases. Due to the absence of any natural specific enzymatic defense system in vivo, the consumption of certain foods which exhibit selective suppressive ability as regards NO overproduction might boost the host's protective effects against NO-mediated toxicity. Spices, rich in phenolics, are speculated conceivably to act as potential NO-scavengers or iNOS suppressors. The relative NO-suppressing activity of methanol extracts deriving from nine Mediterranean culinary spices was determined by measuring their inhibitory effect upon NO production for lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. In addition, the specifics of the suppressing mechanism were further explored. All of the spices tested, with the exception of clove, displayed a rather linear dose-dependent NO-suppressing effect without there appearing to exist any effect upon cell viability. Furthermore, the NO-suppressing capacity of certain spices was able to be ranked based upon their IC(50) (the concentration of spice extracts is required to cause 50% inhibition of NO production by LPS-activated RAW 264.7 cells), the ranking appearing as: rosemary (0.031%)>tarragon (0.052%)>cinnamon (0.059%)>oregano (0.106%)>basil (0.162%)>marjoram (0.236%)>allspice (0.269%)>and thyme (0.270%). Only cinnamon displayed excellent NO-scavenging ability, whereas all of the other spices demonstrated moderate to poor activities in this regard. Moreover, the inhibitory effect of tested spices upon the iNOS protein level was almost equivalent to their suppressive effect upon NO production. It would appear that inhibition of iNOS expression was the primary mechanism of action of spices as regards their exerting NO-suppressing activity.

Animals↗

Antimicrobial and antiplasmid activities of essential oils.

The antimicrobial and antiplasmid activities of essential oils (orange oil, eucalyptus oil, fennel oil, geranium oil, juniper oil, peppermint oil, rosemary oil, purified turpentine oil, thyme oil, Australian tea tree oil) and of menthol, the main component of peppermint oil, were investigated. The antimicrobial activities were determined on the Gram (+) Staphylococcus epidermidis and the Gram (-) Escherichia coli F'lac K12 LE140, and on two yeast Saccharomyces cerevisiae 0425 delta/1 and 0425 52C strains. The antiplasmid activities were investigated on E. coli F'lac bacterial strain. Each of the oils exhibited antimicrobial activity and three of them antiplasmid action. The interaction of peppermint oil and menthol with the antibiotics was studied on the same bacterial strain with the checkerboard method. Peppermint oil and menthol displayed additive synergy with oxytetracycline. A new mechanism of plasmid curing was established for one of the oil components.

Anti-Bacterial Agents↗

Antimicrobial effect of spices and herbs on Vibrio parahaemolyticus.

The antimicrobial effects of spices and herbs from 18 plant species were examined on a foodborne pathogen, Vibrio parahaemolyticus, with the use of combinations of temperatures and nutrient levels. Basil, clove, garlic, horseradish, marjoram, oregano, rosemary, and thyme exhibited antibacterial activities at incubation of 30 degrees C, while with the exception of horseradish, the same spices and additional 7 species exhibited the activities at 5 degrees C. The lowest MIC (minimum inhibitory concentration) was 0.125% observed in clove and marjoram at 30 degrees C in a nutrient rich medium. Lowering of incubation temperature produced little effect on the MICs except for turmeric. The decreasing of the MIC in turmeric appeared to be basically attributed to the sensitivity of the bacterium to coldness. In nutrient poor medium, the lowest was 0.001 and 0.00025% in marjoram at 30 degrees C and at 5 degrees C, respectively. The sensitivity to several spices and herbs was similar among different clinical serotypes including the emerging strain O3:K6. These results suggest that the spices and herbs can be practical for protecting seafood from the risk of contamination by V. parahaemolyticus and used in hurdle technology with low temperature.

Anti-Bacterial Agents↗

Application of sludge from urban wastewater treatment plants in road's embankments.

While different kinds of compost have been tested for highway revegetation, sewage sludge has only been used for agricultural purposes. In this work, its application for helping vegetation establishment on roads embankments is studied. Testing areas measuring 4x5m were constructed on a new highway embankment in an arid location. Several variables are analyzed: side slope (2); sludge dosage (4); vegetative species (4). Results are presented on growth, survival rate and germination of the plants; colonization of other species; cover crop for the plots; estimation of the erosion. The species planted manually showed satisfactory results although any variable was specially significant in this case. However, in relation to the species planted using hydroseeding, 2:1 side slope presented better results than 3:2 side slope. Using hydroseeding, the performance of different species was significantly different, thyme did not grow if sludge was not applied and the cover crop was higher in plots with 3:2 side slope than in plots with 2:1 side slope, essentially due to the presence of colonizing species. Finally, the costs of the proposed treatments are figured out, being concluded that, so much from the technical as the economic point of view, it is a viable proposal for sewage sludge management.

Conservation of Natural Resources↗

Influence of fibre coating in headspace solid-phase microextraction-gas chromatographic analysis of aromatic and medicinal plants.

Solid-phase microextraction (SPME) is a solvent-free technique, which is well established in headspace analysis since it is sensitive, because of the concentration factor achieved by the fibres, and selective, because of different coating materials which can be used. The performance of eight commercially available SPME fibres was compared to evaluate the recoveries of some characteristic components with different polarities and structures present in the headspace of four aromatic and medicinal plants: rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), thyme (Thymus vulgaris L.) and valerian (Valeriana officinalis L.). The relative concentration capacity of each fibre on the same components of each plant was also determined by comparing their abundance with that obtained by classical static-headspace GC. The partition coefficient, K1, between the headspace gaseous phase and SPME polymeric coating, and the relative concentration factors, of some of the characteristic components of the plant investigated dissolved in dibutyl phtalate, were also determined, under rigorously standardised analysis conditions. The results showed that the most effective fibres were those consisting of two components, i.e., a liquid phase (polydimethylsiloxane) and a porous solid (carboxen or divinylbenzene, or both).

Chromatography, Gas↗

The chemotaxonomic significance of two bioactive caffeic acid esters, nepetoidins A and B, in the Lamiaceae.

A survey of leaf surface constituents in the family Lamiaceae using HPLC with diode array detection revealed the presence of two characteristic phenolic compounds in many species. The distribution of these phenolics in the Lamiaceae was found to be of taxonomic significance, as they were present in the great majority of species investigated for the subfamily Nepetoideae, including representatives of the well-known genera of culinary herbs, mint, rosemary, sage, thyme and basil. In contrast, they were absent from species of the other subfamilies of Lamiaceae studied and from the related families Verbenaceae, Scrophulariaceae, Acanthaceae and Buddlejaceae. The compounds were isolated from Plectranthus crassus and identified by NMR spectroscopy as the known caffeic acid esters (Z,E)-[2-(3,5-dihydroxyphenyl)ethenyl] 3-(3,4-dihydroxyphenyl)-2-propenoate and (Z,E)-[2-(3,4-dihydroxyphenyl)ethenyl] 3-(3,4-dihydroxyphenyl)-2-propenoate, for which the trivial names nepetoidins A and B are proposed. The presence of this pair of caffeic acid esters adds another character to the chemical, palynological and embryological features distinguishing the Nepetoideae from the other subfamilies of Lamiaceae and related families, and supports the view that the Nepetoideae are a specialised and monophyletic group within the family. Nepetoidin B was shown to have a greater antioxidant activity than gallic, rosmarinic and caffeic acids, and showed activity as an insect phagostimulant. Both compounds were antifungal.

Animals↗

Effects of industrially produced flavours with pro- and antioxidative properties on the formation of the heterocyclic amine PhIP in a model system.

PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) is a heterocyclic aromatic amine belonging to a class of mutagens found in food. This project studied the effects of commercially available flavours of spices on the formation of PhIP, one of the most common heterocyclic aromatic amines in heated meat and fish products. The model reactions were carried out in diethylene glycol. Highest amounts of PhIP were obtained at 200 degrees C, a heating time of 60 min and an equivalent molar ratio of phenylalanine and creatinine. With this model system, the influence of Monascus red and flavours extracted from thyme, marjoram and rosemary on the formation of PhIP was tested. The flavours were added to the model system in different amounts. The oxidative properties were determined with the rancimat method. It was shown that all tested products, independent of their pro- or antioxidative properties, increased PhIP in the model system.

Antioxidants↗

Antibacterial activity of 11 essential oils against Bacillus cereus in tyndallized carrot broth.

The antibacterial activity of 11 essential oils from aromatic plants against the strain INRA L2104 of the foodborne pathogen Bacillus cereus grown in carrot broth at 16 degrees C was studied. The quantity needed by the essential oils of nutmeg, mint, clove, oregano, cinnamon, sassafras, sage, thyme or rosemary to produce 14-1110% relative extension of the lag phase was determined. Total growth inhibition of bacterial spores was observed for some of the antimicrobial agents assayed. The addition of 5 microl cinnamon essential oil per 100 ml of broth in combination with refrigeration temperatures of <or=8 degrees C produced the conditions necessary to inhibit the growth of B. cereus for at least 60 days in a model, refrigerated minimally processed food product, made with carrots and tyndallized. This is especially important considering that the psychrotrophic enterotoxigenic strain of B. cereus INRA TZ415 was able to grow in this substrate at low temperatures in the absence of any essential oil. Furthermore, the study of the sensory characteristics of the final product suggests that the use of cinnamon essential oil can be considered as an alternative to "traditional food preservatives".

Bacillus cereus↗

A preliminary study of the effect of essential oils on skeletal and smooth muscle in vitro.

The pharmacological activity of nine commercial essential oils was studied on the rat isolated phrenic nerve diaphragm preparation and compared with activity on field-stimulated guinea-pig ileum preparations. The essential oils at final bath concentrations of 2 x 10(-5) and 2 x 10(-4) g/ml produced four different effects on skeletal muscle, whilst only a contracture with or without a decrease in response to field stimulation in smooth muscle. The first type of effect on skeletal muscle involved a contracture and inhibition of the twitch response to nerve stimulation shown by a sample of clary sage, dill, fennel, frankincense and nutmeg; a second, shown by thyme produced a contracture without a change in the twitch response; a third, shown by lavender reduced the twitch response alone and the fourth, shown by camphor, increased the size of the twitch response. Angelica root oil at the highest concentration studied showed no response on skeletal muscle.

Animals↗

The potential effectiveness of essential oils as a treatment for headlice, Pediculus humanus capitis.

Essential oils of aniseed, cinnamon leaf, red thyme, tea tree, peppermint, nutmeg, rosemary, and pine were tested in vitro against lice, Pediculus humanus. All the oils except for rosemary and pine were found to be effective in the laboratory when applied in an alcoholic solution and followed by a rinse the following morning in an essential oil/vinegar/water mixture. Peppermint and nutmeg were only used as a blend rather than as individual oils. Problems of solubility and toxicity are discussed, as are possible mechanisms of action. Phenols, phenolic ethers, ketones, and oxides (1,8-cineole) appear to be the major toxic components of these essential oils when used on lice. Aldehydes and sesquiterpenes may also play a role.

Humans↗

Common herbs, essential oils, and monoterpenes potently modulate bone metabolism.

During our survey of herbs looking for activity on bone metabolism, we found that the dried leaves of sage strongly inhibit bone resorption. Therefore, we investigated several common herbs rich in essential oils (sage, rosemary, and thyme) and essential oils extracted from these herbs and other plants (oils of sage, rosemary, juniper, pine, dwarf pine, turpentine, and eucalyptus) as well as their monoterpene components (thujone, eucalyptol, camphor, borneol, thymol, alpha-pinene, beta-pinene, bornylacetate as well as menthol) and found that they inhibit bone resorption when added to the food of rats. Pine oil, used as a representative essential oil, protects an osteoporosis model, the aged ovariectomized rat, from bone loss. The monoterpenes borneol, thymol, and camphor are directly inhibitory in the osteoclast resorption pit assay. Nonpolar monoterpenes may require metabolism to be active in vitro, for example, cis-verbenol, a metabolite of alpha-pinene occurring in human urine, inhibits osteoclast activity in contrast to the parent compound. Within 30 min borneol inhibits the formation of actin rings, a characteristic of resorbing osteoclasts indicating cell polarization. Both the in vitro and the in vivo effects of borneol are reversible. Our study demonstrates for the first time that essential oils and monoterpenes are efficient inhibitors of bone resorption in the rat.

Animals↗

Acute, sublethal, antifeedant, and synergistic effects of monoterpenoid essential oil compounds on the tobacco cutworm, Spodoptera litura (Lep., Noctuidae).

Monoterpenoids (terpenes and biogenically related phenols) commonly found in plant essential oils were tested for acute toxicity via topical application to tobacco cutworms (Spodoptera litura Fab.). The most toxic among 10 such compounds was thymol (LD(50) = 25.4 microg/larva) from garden thyme, Thymus vulgaris. The compounds were then tested for sublethal effects, specifically inhibition of larval growth after topical application of low doses. Among 6 compounds tested, an LD(10) dose reduced growth by 20% on average 3 days after administration. Feeding deterrence was determined using a cabbage leaf disk choice test. The most deterrent compound was thymol, with a DC(50) of 85.6 microg/cm(2) leaf disk area. Because minor constituents in complex essential oils have been suggested to act as synergists, binary mixtures of the compounds were tested for synergy vis à vis acute toxicity and feeding deterrence. trans-Anethole acted synergistically with thymol, citronellal, and alpha-terpineol, in terms of both acute toxicity and feeding deterrence. On the basis of these findings, several complex mixtures were developed and tested as leads for effective control agents. Candidate mixtures demonstrated good synergistic effects. The observed LD(50) of mixture 3 was 40.6 microg/larvae compared to an expected value of 74.6 microg/larvae. The result of this research is a proprietary product suitable for commercial production.

Animals↗

Bacterial susceptibility to and chemical composition of essential oils from Thymus kotschyanus and Thymus persicus.

Susceptibility of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia, and Pseudomonas aeroginosa to the essential oils extracted from two varieties of Thyme, i.e., Thymus kotschyanus Boiss. and Hohen. and Thymus persicus L. at preflowering and flowering stages were studied. The disk diffusion method was used to evaluate the zone of microbial growth inhibition at various concentrations of the oils. Minimal inhibitory concentration and minimal bactericidal concentration of the oils were determined and compared with each other. The oils from the above plants were found to be strongly bactericidal with that of T. kotschyanus being more effective. T. kotschyanusand T. persicus oils analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) lead to identification of 33 and 26 components, respectively. The profile of the oil components from T. persicuswas similar to that of T. kotschyanus in almost all of the compounds but at different concentrations. The major components of T. kotschyanus oil before and at the flowering stages were carvacrol (35.06, 22.75%), thymol (26.60, 16.52%), gamma-terpinene (7.81, 0.34%), gamma-terpinene (4.34, 0%), borneol (2.29, 4.52%), myrcene (0.26, 12.65%), thymolquinone (0, 11.39%), nerol (0, 6.10%), and beta-caryophyllene (0, 5.54%), respectively, and those of T. persicus at the same stages were carvacrol (38.96, 27.07%), thymol (6.48, 11.86%), P-cymene (7.51, 10.16%), gamma-terpineol (0, 9.51%), nerol (15.66, 9.41%), gamma-terpinene (6.11, 6.51%), and thymol acetate (5.29, 5.30%), respectively. The contribution of oil components to its antibacterial property is discussed. High aromatic compound content of the phenol-rich oils seems to account for strong antibacterial activity.

Anti-Bacterial Agents↗