37 research outputs found
Evaluation of the genotoxic and antigenotoxic potential of Melissa officinalis in mice
Melissa officinalis (L.) (Lamiaceae), a plant known as the lemon balm, is native to the east Mediterranean region and west Asia. Also found in tropical countries, such as Brazil, where it is popularly known as “erva-cidreira” or “melissa”, it is widely used in aqueous- or alcoholic-extract form in the treatment of various disorders. The aim was to investigate in vivo its antigenotoxicity and antimutagenicity, as well as its genotoxic/mutagenic potential through comet and micronucleus assaying. CF-1 male mice were treated with ethanolic (Mo-EE) (250 or 500 mg/kg) or aqueous (Mo-AE) (100 mg/kg) solutions of an M. officinalis extract for 2 weeks, prior to treatment with saline or Methyl methanesulfonate (MMS) doses by intraperitoneal injection. Irrespective of the doses, no genotoxic or mutagenic effects were observed in blood and bone-marrow samples. Although Mo-EE exerted an antigenotoxic effect on the blood cells of mice treated with the alkylating agent (MMS) in all the doses, this was not so with Mo-AE. Micronucleus testing revealed the protector effect of Mo-EE, but only when administered at the highest dose. The implication that an ethanolic extract of M. officinalis has antigenotoxic/antimutagenic properties is an indication of its medicinal relevance
Analyzing factors that influence the folk use and phytonomy of 18 medicinal plants in Navarra
BACKGROUND: This article analyzes whether the distribution or area of use of 18 medicinal plants is influenced by ecological and cultural factors which might account for their traditional use and/or phytonymy in Navarra. This discussion may be helpful for comparative studies, touching as it does on other ethnopharmacological issues: a) which cultural and ecological factors affect the selection of medicinal plants; b) substitutions of medicinal plants in popular medicine; c) the relation between local nomenclature and uses. To analyze these questions, this paper presents an example of a species used for digestive disorders (tea and camomile: Jasonia glutinosa, J. tuberosa, Sideritis hyssopifolia, Bidens aurea, Chamaemelum nobile, Santolina chamaecyparissus...), high blood pressure (Rhamnus alaternus, Olea europaea...) or skin diseases (Hylotelephium maximum, H. telephium, Anagallis arvensis, A. foemina). METHODS: Fieldwork began on January 2004 and continued until December 2006. During that time we interviewed 505 informants in 218 locations in Navarra. Information was collected using semi-structured ethnobotanical interviews, and we subsequently made maps using Arc-View 8.0 program to determine the area of use of each taxon. Each map was then compared with the bioclimatic and linguistic map of Navarra, using the soil and ethnographic data for the region, and with other ethnobotanical and ethnopharmacological studies carried out in Europe. RESULTS: The results clearly show that ecological and cultural factors influence the selection of medicinal plants in this region. Climate and substrate are the most important ecological factors that influence the distribution and abundance of plants, which are the biological factors that affect medicinal plant selection. CONCLUSION: The study of edaphological and climatological factors, on the one hand, and culture, on the other, can help us to understand why a plant is replaced by another one for the same purposes, either in the same or in a different area. In many cases, the cultural factor means that the use of a species is more widespread than its ecological distribution. This may also explain the presence of synonyms and polysemies which are useful for discussing ethnopharmacological data
Identification of the antimicrobial substances produced by Solanum palinacanthum (Solanaceae)
Chemical composition and antibacterial activity of Aloysia triphylla (L'Hérit) Britton extracts obtained by pressurized CO2 extraction
Investigating the role of the coupling between the ocean, the sea ice and the atmosphere in the biogeochemical cycle of CH4
The contribution of the ocean to the atmospheric methane (CH4) budget is poorly understood. In polar regions, this contribution is further influenced by the sea-ice cover. Sea ice has long been considered as an inert and impermeable barrier, but recent studies have highlighted the existence of gas fluxes at the atmosphere–sea-ice and sea-ice–seawater interfaces. These fluxes are to date poorly characterized and quantified, so that the role of sea ice as a net sink or source of CH4 is still unclear. The PIPERS (Polynyas, Ice Production, and seasonal Evolution in the Ross Sea) expedition on the icebreaker Nathaniel B. Palmer provided a unique opportunity to investigate the complex coupling between the ocean, the sea ice and the atmosphere, at the beginning of winter 2017. As the season was progressing, we could study how sea-ice formation influences the biogeochemical cycle of CH4. We performed continuous measurements of dissolved CH4 in surface waters together with CH4 mixing ratio in the atmosphere. Discrete samples were also collected both to calibrate continuous systems and to carry out subsequent stable isotope analyses. A total of 17 ice cores dedicated to CH4 concentration measurements were drilled in the Ross Sea pack ice and in the vicinity of the Terra Nova Bay polynya. Additional analyses, such as characterization of ice texture and physical properties, were conducted on these cores. This multiparametric dataset will allows us to determine the distribution of CH4 between the ocean, the sea ice and the atmosphere during sea-ice formation and help us to unravel the net role of sea ice in the CH4 budget
Technical Note: On the use of the mushy-layer Rayleigh number for the interpretation of sea-ice-core data
International audienceWe examine some practical aspects of using a mushy-layer Rayleigh number for the interpretation of sea-ice-core data. In principle, such analysis should allow one to determine convectively active regions within the ice core by identifying those regions in which the mush-Rayleigh number is super-critical. In practice, however, a quantitative analysis is complicated by uncertainties regarding the specific formulation of both the mush-Rayleigh number itself and of the sea-ice permeability that is crucial for quantifying the Rayleigh number. Additionally, brine loss from highly permeable sections of the ice core, in particular close to the ice-ocean interface, and typically weekly ice core sampling, limit the practical applicability of the Rayleigh number for ice-core interpretation. We here quantify these uncertainties, suggest a standard method for the computation of the Rayleigh number for sea ice and discuss possibilities and limitations of ice-core interpretation based on the Rayleigh number