Recherche de sens et stratégies de soins chez les Mwalebeng de Pouebo (Nouvelle-Calédonie)

Le rapport à la santé chez les populations kanak (Nouvelle-Calédonie) se comprend dans une complexité de relations entre humains et non-humains. La qualité des relations avec les membres de la famille, les clans, les autres, qu’ils soient humains ou non-humains, est une source de bien-être et de bonne santé. Prendre soin de soi repose sur le maintien de ces liens ainsi que sur divers savoirs thérapeutiques détenus par tous ou par des sachants spécialisés. Cependant, actuellement, le recours aux services de centres médico-sociaux est devenu quasi-systématique, délaissant ainsi les décoctions et les savoirs thérapeutiques traditionnels. Cet article basé sur une enquête de type ethnographique auprès des populations kanak de Mwalebeng (Pouebo) tente de montrer qu’au-delà des changements qui sont perçus et vécus dans le rapport à la santé, s’observe une permanence de schémas de pensée, comme la quête de sens face aux divers problèmes de santé rencontrés.The relationship to health among the Kanak (New Caledonia) must be interpreted in the context of complex relations between humans and non-humans. The quality of relationships with family members, clans, and others, whether human or non-human, are sources of well-being and good health. Taking care of oneself requires to maintain such links, and relies upon various therapeutic knowledge, be they shared by all or in the custody of local experts. However, at present, recourse to “medical-social centres” has become almost systematic, and traditional therapeutic knowledge and remedies are being abandoned. This article, based on an ethnographic survey of the Kanak of Mwalebeng (Pouebo), attempts to show that, beyond the changes that are perceived and experienced in relation to health, certain patterns of thought, such as the search for meaning in response to ill-health, are still present

Acaricidal activity of essential oils from five endemic conifers of New Caledonia on the cattle tick Rhipicephalus (Boophilus) microplus

International audienceThe aim of the present study was to demonstrate acaricidal activity on the cattle tick Rhipicephalus (Boophilus) microplus of essential oils from endemic conifers of New Caledonia in the context of the development of natural alternatives. Acaricidal activity of essential oils extracted from resin and heartwood of five endemic conifers of New Caledonia (Araucaria columnaris, Agathis moorei, Agathis ovata, Callitris sulcata, and Neocallitropsis pancheri) was evaluated on 14- to 21-day-old Rhipicephalus microplus tick larvae using the Larval Packal Test bioassay. A first screening with 5 % dilute solution was carried out and the oils with 100 % of mortality at this rate were diluted until no activity was shown. The heartwood oils of the two Cupressaceae were the most active with LC50 value of 0.65 % for C. sulcata and 0.55 % for N. pancheri while resin oil of A. columnaris (LC50=1.62 %) was the most active of the Araucariaceae family. Negative control (ethanol) was not toxic to the larvae. The chemical composition of essential oil from resin of A. columnaris was analyzed by gas chromatography-mass spectrometry. The essential oil was characterized by high level of sesquiterpene hydrocarbons and oxygenated sesquiterpenes and was composed mainly of aromadendrene (23.1 %) and bicyclogermacrene (16.0 %). In order to compare different plant resources in a sustainable program of natural acaricide, an "essential oil efficiency EOE" can be measured as the ratio between the yield of extraction and LC50 value. This study shows that A. columnaris (EOE=2.36) and N. pancheri (EOE=3.51) could provide valuable and effective natural acaricides for control of the cattle tick R. microplus

Puisque c'est possible. Itinéraires scientifiques en Nouvelle-Calédonie

À la croisée de l’innovation technologique et des savoirs traditionnels, deux jeunes scientifiques racontent leur parcours, leurs motivations et leurs ambitions. Ils sont soutenus par les chercheurs de l’Institut de recherche pour le développement (IRD) en Nouvelle-Calédonie.Emmrick SAULIA, microbiologiste et A-Tena PIDJO, doctorante en anthropologie souhaitent que leurs recherches soient utiles et contribuent à la construction de leur pays, à son rayonnement dans la région Pacifique.Sophie BONNET, océanographe, Catherine SABINOT, anthropologue et Édouard HNAWIA, ethnobotaniste, les accompagnent dans cette démarche

Puisque c'est possible. Itinéraires scientifiques en Nouvelle-Calédonie

À la croisée de l’innovation technologique et des savoirs traditionnels, deux jeunes scientifiques racontent leur parcours, leurs motivations et leurs ambitions. Ils sont soutenus par les chercheurs de l’Institut de recherche pour le développement (IRD) en Nouvelle-Calédonie.Emmrick SAULIA, microbiologiste et A-Tena PIDJO, doctorante en anthropologie souhaitent que leurs recherches soient utiles et contribuent à la construction de leur pays, à son rayonnement dans la région Pacifique.Sophie BONNET, océanographe, Catherine SABINOT, anthropologue et Édouard HNAWIA, ethnobotaniste, les accompagnent dans cette démarche

Puisque c'est possible. Itinéraires scientifiques en Nouvelle-Calédonie

À la croisée de l’innovation technologique et des savoirs traditionnels, deux jeunes scientifiques racontent leur parcours, leurs motivations et leurs ambitions. Ils sont soutenus par les chercheurs de l’Institut de recherche pour le développement (IRD) en Nouvelle-Calédonie.Emmrick SAULIA, microbiologiste et A-Tena PIDJO, doctorante en anthropologie souhaitent que leurs recherches soient utiles et contribuent à la construction de leur pays, à son rayonnement dans la région Pacifique.Sophie BONNET, océanographe, Catherine SABINOT, anthropologue et Édouard HNAWIA, ethnobotaniste, les accompagnent dans cette démarche

New Sulfur-Containing Polyarsenicals from the New Caledonian Sponge Echinochalina bargibanti

Arsenicin A (C3H6As4O3) was isolated from the New Caledonian poecilosclerid sponge Echinochalina bargibanti, and described as the first natural organic polyarsenic compound. Further bioguided fractionation of the extracts of this sponge led us to isolate the first sulfur-containing organic polyarsenicals ever found in Nature. These metabolites, called arsenicin B and arsenicin C, are built on a noradamantane-type framework that is characterized by an unusual As-As bonding. Extensive NMR measurements, in combination with mass spectra, enabled the assignment of the structure for arsenicin B (C3H6As4S2) as 2. The scarcity of arsenicin C and its intrinsic chemical instability only allowed the collection of partial spectral data, which prevented the full structural definition. After the extensive computational testing of several putative structures, structure 3 was inferred for arsenicin C (C3H6As4OS) by comparing the experimental and density functional theory (DFT)-calculated H-1 and C-13 NMR spectra. Finally, the absolute configurations of 2 and 3 were determined with a combined use of experimental and time-dependent (TD)-DFT calculated electronic circular dichroism (ECD) spectra and observed specific rotations. These findings pose great challenges for the investigation of the biosynthesis of these metabolites and the cycle of arsenic in Nature. Arsenicins B and C showed strong antimicrobial activities, especially against S. aureus, which is comparable to the reference compound gentamycin

Polyphenols as superoxide dismutase modulators and ligands for estrogen receptors

International audienceThe capacity of estrogen and stilbene derivatives to modulate the activity of superoxide dismutases in relation with their estrogenic properties has been studied. The properties of trans-resveratrol (3,5,4′-trihydroxystilbene) and its analogues, 4-hydroxystilbene, 4,4′-dihydroxystilbene, 3,5-dihydroxystilbene, 3,5,4′-trimethoxystilbene and 4,4′-dihydroxy-3,5,3′,5′-tetramethylstilbene were compared to 17β-estradiol and its analogues (2-methoxyestradiol, estrone, 2-hydroxyestradiol and 2-methoxyestrone). Measurement of estrogen receptor-β (ER-β) binding capacity was carried out by a receptor competitor assay associated with fluorescence polarisation detection. The superoxide dismutase (SOD) modulation activity was followed with a spectrophotometric assay using the sequence xanthine/xanthine oxidase-2,3-bis[2-methoxy-4-nitro-sulfo-phenyl]-2H-tetrazolium-5-carboxanilide (X/XO-XTT). The structure–activity relationship was different for the two series tested. In the estrogenic series, a compound which does not inhibit SOD, is recognized by the ER-β. In contrast for the stilbenic series both properties are parallel each other