Enquête sur la survenue d’intoxications après l’utilisation d’huiles essentielles, comparaison avec les données du CAP d’Angers (2017-2018)

National audienceObjectifs : Les médecines non conventionnelles ne sont pas dénuées de toxicité et il est pertinent d’établir un état des lieux des connaissances du grand public vis-à-vis des huiles essentielles. Il s’agit d’identifier le profil des victimes d’une intoxication, les voies d’administration et les symptômes ainsi que les huiles essentielles incriminées.Méthodes : Deux enquêtes, à destination du grand public et des professionnels de santé, ont été diffusées (janvier-mars 2019). En complément, les données du centre antipoison d’Angers sur la période 2017-2018 ont été analysées et comparées avec les données de notre enquête.Résultats : Nos enquêtes rassemblent 623 et 59 réponses. Les données du centre antipoison d’Angers recensent 741 intoxications. Les précautions d’emploi et les contre-indications des huiles essentielles sont peu connues puisque 5% des répondants les identifient correctement. Nos données mettent en évidence qu’une utilisation en mélange augmente le risque d’intoxication (p < 0,02). Les huiles essentielles les plus citées en cas d’intoxication sont l’Eucalyptus, le Tea tree et la Lavande. Les symptômes occasionnés concernent majoritairement une application cutanée (75%) et restent de courte durée et sans gravité. Lors d’une déclaration au centre antipoison d’Angers, ces mêmes huiles essentielles sont impliquées, la voie orale est majoritaire utilisée (70%) et les symptômes répertoriés pour 74% des intoxications concernent des douleurs oropharyngées, oculaires, abdominales et cutanées.Conclusion : La délivrance des huiles essentielles n’est pas anodine et les données obtenues tant à travers l’enquête que le traitement des données du centre antipoison d’Angers montrent qu’elles doivent être utilisées avec prudence

Phytochemical investigation of a lichen from Brittany, Stereocaulon evolutum Graewe

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Myriolecis massei, a new species of Lecanoraceae from the coasts of the Armorican Massif in Western Europe

International audienceA new species of Lecanora s.l. (Lecanoraceae) has been found in several localities on the coasts of the Armorican Massif (Brittany, Normandy, Channel Islands), only on siliceous rocks in the supralittoral zone. It is particularly distinguished by its well-developed thallus reacting C+ orange in the cortex and containing chlorinated xanthones identified by HPLC-DAD-MS. Placed in the new genus Myriolecis, it is described in this study as Myriolecis massei sp. nov. and is compared to similar maritime species containing chloroxanthones. A key is given to European maritime species of Myriolecis reacting C+. Copyright © 2018 by The American Bryological Society, Inc

Stability of oral liquid preparations of methylergometrine

International audienceThe stability of an oral ready to-use form of methylergometrine (0.05 mg/mL), which provides a convenient volume for administration (5 mL), was evaluated over a forty-seven-day period at different temperatures (5 degrees C and room temperature) without light in order to assign a shelf life. Methylergometrine was assayed by a stability-indicating HPLC method with diode array detection. The drug undergoes degradation under basic conditions and dry heat (50 degrees C). All the peaks of the degraded product were resolved from the standard drug with significantly different retention times. Statistical analysis proves that the method is reproducible and accurate for estimation of the intact drug. The pH of samples was monitored periodically for changes. Samples were also visually inspected for any colour change, precipitation or crystallization. At least, 96% of the initial methylergometrine concentration remained throughout the 47-day study period. Over the test period, no significant change was observed in the pH or colour of any of the samples. No degradation products were revealed. This study allowed an oral ready to use solution of methylergometrine (0.05 mg/ml) to be prepared, with a shelf life of more than one month (47 days) when stored at room temperature without light

Comparative studies on two Sumatran lichens: Sterocaulon halei and S. montagneanum

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Lichenic extracts and metabolites as UV filters.

International audienceThree lichen extracts and ten lichenic compounds have been screened for their photoprotective activities. The determination of their Sun Protection Factor (SPF) and Protection Factor-UVA (PF-UVA) values was done in vitro. Among them, a Lasallia pustulata extract and gyrophoric acid exhibited SPF values over 5, which is better than Homosalate (SPF≈4). Their photoprotective properties are only slightly modified after a 2-hours period of irradiation. Salazinic acid and L. pustulata presented characteristics of a UVA booster like the butyl-methoxydibenzoylmethane (Avobenzone) (PF-UVA≈2 vs. 2.8 for Avobenzone). Salazinic acid was a better anion superoxide scavenger than ascorbic acid and none of them exhibited a photosensitizing cytotoxicity by exposing them on HaCaT cells to UVA radiations (photo-irritancy factor PIF<5)

Oxidative stress regulation in lichens and its relevance for survival in coastal habitats

International audienceLichens are symbiotic systems able to survive in harsh conditions like those on coastal rocks with rapid changes in the concentration of salt, immersion, desiccation-rehydratation cycle, wind, waves and herbivorie. These stresses are at the origin of reactive oxygen species (ROS) production in lichens. Physical barriers, enzymatic systems and cellular contents of glutathione, ascorbic acid and tocopherols are involved in lichen defence systems against ROS. But which role have specific lichen compounds, e.g.: the depsides, depsidones, dibenzofuranes, diphenylethers as antioxidants? In order to answer this question, antioxidant studies were recorded and analysed for studies for lichens that occur on coastal rocks. Based on the methods used in the experiments (hydrogen atom transfer (HAT), electron transfer (ET), enzymatic assays, specific ROS scavenging, in vivo assays), lichen compounds seemed to be poor hydrogen acceptors and electron donors but appeared as potent ROS specific scavengers, they might act as antioxidants as proved by the positive results of many lichen extracts in antioxidant assays

Lobarin from the Sumatran lichen, Stereocaulon halei.

International audienceThe diphenyl ether, lobarin (1) (syn. lobariol carboxylic acid) related to lobaric acid was isolated for the first time as a natural product along with five known compounds from Stereocaulon halei, a fruticose lichen collected in Indonesia. The structure of lobarin was elucidated by spectroscopic data analysis and its most stable conformers were determined by molecular mechanic dynamic calculations. A marked superoxide anion scavenging was found for compound 1 while no cytotoxicity on the B16 murine melanoma and HaCaT human keratinocyte cell lines was observed