Towards the Clinical Use of Phytoplankton Carotenoid Pigments to Cure Cancer

International audienceBeyond their major ecolophysiological functions, phytoplankton pigments exert biological and pharmacological activities in human cells that allow considering their clinical use to cure various pathologies. Although much of our knowledge relating to their cell pharmacology and bioactivity has come from in vitro studies in cell culture models, recent in vivo studies have validated the potential of phytoplankton carotenoid pigments to limit inflammation and metabolic disorders, retinal diseases, degenerative diseases, tumor progression, and hepatotoxicity. Aside from these promising results, additional studies are now required to precise their pharmacokinetics, pharmacological targets, and clinical efficacy in humans. The availability of highly purified pigments at rational costs will be a milestone to set up clinical trials and develop new therapies using microalgae pigments. This short paper focuses on the great potential of phytoplankton carotenoid pigments to prevent and cure cancers. Marine and freshwater microalgae have evolved a wide range of pigments that belong to the chlorophylls, carotenoids and phycobiliproteins families. Extensive research has proved that microalgae pigments exert significant biological and pharmacological activities in human cells. Beyond their well-known antioxidant activity, used as a commercial argument to sell algae-based cosmetics and nutraceutics, it is now clearly established that microalgae pigments have a great potential as health nutrients to prevent cancer, as biotechnological probes for cancer diagnosis and as anticancer drugs to trigger cancer cells apoptosis, prevent tumor angiogenesis, reduce the risk of metastasis, sensitize cancer cells to chemotherapy, destroy cancer cells by tumor phototherapy and filter UV to limit cancer cells initiation. Numerous studies aiming to identify antiproliferative molecules from microalgae extracts led to the isolation of carotenoids and to the demonstration of their high antiproliferative, cytostatic, cytotoxic, and/or pro-apoptotic activity in cancer cell cultures [1,2]. As an example, our research team performed the bioguided isolation of pigments from Duniella tertiolecta and found that violaxanthin was the most antiproliferative molecule contained in Dt dichloromethane extract [3]. We also recently reported the strong antiproliferative activity of zeaxanthin and β-cryptoxanthin in human invasive melanoma cells, after their bioguided isolation from Cyanophora paradoxa ethanolic extracts [4]

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

Extraction, identification et caractérisation pharmacologique de pigments de Porphyridium purpureum sur cellules de mélanome humain

20 000 Europeans die from melanoma each year and this number is constantly increasing. Melanoma cells are mainly characterized by the mutation of the RAS, B-RAF and RHO-B kinases. Because of these mutations, the cells are resistant to chemotherapeutic agents. A lot of studies have established that the algae pigments are of major interest to prevent diagnose and treat cancers. The objective of this thesis is to undertake an integrated research work to identify microalgae pigments that may be relevant for the diagnosis or treatment of melanomas and to characterize their pharmacological activity. We selected Porphyridium purpureum, a species which contains phycobiliproteins, carotenoids including zeaxanthin. We developed innovative processes for the extraction and identification of microalgae pigments. This work resulted in the first extraction of phycobiliproteins under microwave-assisted irradiations, and the identification of microalgae pigments by UPLC-MSE within a complex mixture. Moreover, we demonstrated the proapoptotic activity of zeaxanthin and the characterization of its mode of action on A2058 human melanoma cells. The CI50 obtained for this pigment is lower than that of cisplatin (chemotherapeutic drug). These results show the great potential of this pigment for the treatment of melanoma which are resistant to chemotherapy.20 000 Européens meurent chaque année du mélanome et le taux de mortalité ne cesse de s’accroître. Les cellules de mélanome se caractérisent principalement par la mutation des kinases RAS, B-RAF et RHO-B. Ces mutations leur confèrent une résistance aux agents chimiothérapeutiques. Un grand nombre de travaux a établi que les pigments d’algues présentent un intérêt majeur pour prévenir, diagnostiquer et traiter les cancers. L’objectif de ce travail de thèse est de réaliser un travail de recherche intégré pour identifier des pigments de microalgues pouvant présenter un intérêt pour le diagnostic ou le traitement des mélanomes et de caractériser leur activité pharmacologique. Notre choix s’est porté sur Porphyridium purpureum, une espèce qui contient des phycobiliprotéines, des caroténoïdes dont la zéaxanthine. Nous avons développé des procédés innovants pour l’extraction et l’identification des pigments de microalgues. Ce travail a permis de réaliser la première extraction de phycobiliprotéines assistée sous champ microondes ainsi que l’identification des pigments de microalgue par UPLC-MSE au sein d’un mélange complexe. De plus, nous avons montré l’activité pro-apoptotique de la zéaxanthine et la caractérisation de son mode d’action sur les cellules de mélanome humain A2058. L’IC50 obtenue pour ce pigment est inférieure à celle du cisplatine (agent chimiothérapeutique). Ces résultats montrent le fort potentiel de ce pigment pour le traitement du mélanome résistant à la chimiothérapie

Extraction, identification and pharmalogical caracterisation of Porphyridium purpureum pigments in human melanoma cells

20 000 Européens meurent chaque année du mélanome et le taux de mortalité ne cesse de s’accroître. Les cellules de mélanome se caractérisent principalement par la mutation des kinases RAS, B-RAF et RHO-B. Ces mutations leur confèrent une résistance aux agents chimiothérapeutiques. Un grand nombre de travaux a établi que les pigments d’algues présentent un intérêt majeur pour prévenir, diagnostiquer et traiter les cancers. L’objectif de ce travail de thèse est de réaliser un travail de recherche intégré pour identifier des pigments de microalgues pouvant présenter un intérêt pour le diagnostic ou le traitement des mélanomes et de caractériser leur activité pharmacologique. Notre choix s’est porté sur Porphyridium purpureum, une espèce qui contient des phycobiliprotéines, des caroténoïdes dont la zéaxanthine. Nous avons développé des procédés innovants pour l’extraction et l’identification des pigments de microalgues. Ce travail a permis de réaliser la première extraction de phycobiliprotéines assistée sous champ microondes ainsi que l’identification des pigments de microalgue par UPLC-MSE au sein d’un mélange complexe. De plus, nous avons montré l’activité pro-apoptotique de la zéaxanthine et la caractérisation de son mode d’action sur les cellules de mélanome humain A2058. L’IC50 obtenue pour ce pigment est inférieure à celle du cisplatine (agent chimiothérapeutique). Ces résultats montrent le fort potentiel de ce pigment pour le traitement du mélanome résistant à la chimiothérapie.20 000 Europeans die from melanoma each year and this number is constantly increasing. Melanoma cells are mainly characterized by the mutation of the RAS, B-RAF and RHO-B kinases. Because of these mutations, the cells are resistant to chemotherapeutic agents. A lot of studies have established that the algae pigments are of major interest to prevent diagnose and treat cancers. The objective of this thesis is to undertake an integrated research work to identify microalgae pigments that may be relevant for the diagnosis or treatment of melanomas and to characterize their pharmacological activity. We selected Porphyridium purpureum, a species which contains phycobiliproteins, carotenoids including zeaxanthin. We developed innovative processes for the extraction and identification of microalgae pigments. This work resulted in the first extraction of phycobiliproteins under microwave-assisted irradiations, and the identification of microalgae pigments by UPLC-MSE within a complex mixture. Moreover, we demonstrated the proapoptotic activity of zeaxanthin and the characterization of its mode of action on A2058 human melanoma cells. The CI50 obtained for this pigment is lower than that of cisplatin (chemotherapeutic drug). These results show the great potential of this pigment for the treatment of melanoma which are resistant to chemotherapy

Do raspberry extracts and fractions have antifungal or anti-adherent potential against Candida spp.?

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Débuter en japonais

Lorsque l’on sort du lycée et qu’on entre dans une nouvelle structure scolaire telle qu’une université, le changement s’avère difficile. Mal orienté, un nouvel élève peut vite se retrouver dépassé par la situation, et échouer sa première année d’étude. Le film réalisé est une sorte de guide pour conseiller les nouveaux étudiants en L1, ou les lycéens souhaitant intégrer l’INALCO, pour les aider à s’adapter à leur nouvelle vie estudiantine. « Débuter en Japonais » présente donc le département japonais de l'INALCO (Institut National des Langues et Civilisations Orientales) tout en évoquant les questionnements et doutes des débutants de première année de licence, auxquels répondent les étudiants de deuxième année. Un enseignant, Emmanuel Lozerand, présente à son tour le département d'un point de vue professoral, en évoquant certains des doutes des étudiants, et en citant les nombreux avantages que présente cette filière aux ressources multiples

UPLC-MSE Profiling of Phytoplankton Metabolites: Application to the Identification of Pigments and Structural Analysis of Metabolites in Porphyridium purpureum

A fast and high-resolution UPLC-MSE analysis was used to identify phytoplankton pigments in an ethanol extract of Porphyridium purpureum (Pp) devoid of phycobiliproteins. In a first step, 22 standard pigments were analyzed by UPLC-MSE to build a database including retention time and accurate masses of parent and fragment ions. Using this database, seven pigments or derivatives previously reported in Pp were unequivocally identified: beta,beta-carotene, chlorophyll a, zeaxanthin, chlorophyllide a, pheophorbide a, pheophytin a, and cryptoxanthin. Minor amounts of Divinyl chlorophyll a, a chemotaxonomic pigment marker for prochlorophytes, were also unequivocally identified using the database. Additional analysis of ionization and fragmentation patterns indicated the presence of ions that could correspond to hydroxylated derivatives of chlorophyll a and pheophytin a, produced during the ethanolic extraction, as well as previously described galactosyldiacylglycerols, the thylakoid coenzyme plastoquinone, and gracilamide B, a molecule previously reported in the red seaweed Gracillaria asiatica. These data point to UPLC-MSE as an efficient technique to identify phytoplankton pigments for which standards are available, and demonstrate its major interest as a complementary method for the structural elucidation of ionizable marine molecules