Browsing by Author "Contreras-Porcia, Loretto"

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    Characterization of an Agarophyton chilense Oleoresin Containing PPARγ Natural Ligands with Insulin-Sensitizing Effects in a C57Bl/6J Mouse Model of Diet-Induced Obesity and Antioxidant Activity in Caenorhabditis elegans
    (2021) Pinto, Claudio; Raquel Ibanez, Maria; Loyola, Gloria; Leon, Luisa; Salvatore, Yasmin; Gonzalez, Carla; Barraza, Victor; Castaneda, Francisco; Aldunate, Rebeca; Contreras-Porcia, Loretto; Fuenzalida, Karen; Bronfman, Francisca C.
    The biomedical potential of the edible red seaweed Agarophyton chilense (formerly Gracilaria chilensis) has not been explored. Red seaweeds are enriched in polyunsaturated fatty acids and eicosanoids, which are known natural ligands of the PPAR gamma nuclear receptor. PPAR gamma is the molecular target of thiazolidinediones (TZDs), drugs used as insulin sensitizers to treat type 2 diabetes mellitus. Medical use of TZDs is limited due to undesired side effects, a problem that has triggered the search for selective PPAR gamma modulators (SPPARMs) without the TZD side effects. We produced Agarophyton chilense oleoresin (Gracilex(R)), which induces PPAR gamma activation without inducing adipocyte differentiation, similar to SPPARMs. In a diet-induced obesity model of male mice, we showed that treatment with Gracilex(R) improves insulin sensitivity by normalizing altered glucose and insulin parameters. Gracilex(R) is enriched in palmitic acid, arachidonic acid, oleic acid, and lipophilic antioxidants such as tocopherols and beta-carotene. Accordingly, Gracilex(R) possesses antioxidant activity in vitro and increased antioxidant capacity in vivo in Caenorhabditis elegans. These findings support the idea that Gracilex(R) represents a good source of natural PPAR gamma ligands and antioxidants with the potential to mitigate metabolic disorders. Thus, its nutraceutical value in humans warrants further investigation.
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    Differential gene expression in Pyropia columbina (Bangiales, Rhodophyta) under natural hydration and desiccation conditions
    (2013) Contreras-Porcia, Loretto; Lopez-Cristoffanini, Camilo; Lovazzano, Carlos; Rosa Flores-Molina, Maria; Thomas, Daniela; Nunez, Alejandra; Fierro, Camila; Guajardo, Eduardo; Correa, Juan A.; Kube, Michael; Reinhardt, Richard
    In rocky shores, desiccation is triggered by daily tide changes, and experimental evidence suggests that local distribution of algal species across the intertidal rocky zone is related to their capacity to tolerate desiccation. In this context, the permanence of Pyropia columbina in the high intertidal rocky zone is explained by its exceptional physiological tolerance to desiccation. This study explored the metabolic pathways involved in tolerance to desiccation in the Chilean P. columbina, by characterizing its transcriptome under contrasting conditions of hydration. We obtained 1,410 ESTs from two subtracted cDNA libraries in naturally hydrated and desiccated fronds. Results indicate that transcriptome from both libraries contain transcripts from diverse metabolic pathways related to tolerance. Among the transcripts differentially expressed, 15% appears involved in protein synthesis, processing and degradation, 14.4% are related to photosynthesis and chloroplast, 13.1% to respiration and mitochondrial function (NADH dehydrogenase and cytochrome c oxidase proteins), 10.6% to cell wall metabolism, and 7.5% are involved in antioxidant activity, chaperone and defense factors (catalase, thioredoxin, heat shock proteins, cytochrome P450). Both libraries highlight the presence of genes/ proteins never described before in algae. This information provides the first molecular work regarding desiccation tolerance in P. columbina, and helps, to some extent, explaining the classical patterns of ecological distribution described for algae across the intertidal zone.
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    Expansion of marine pollution along the coast: Negative effects on kelps and contamination transference to benthic herbivores?
    (2023) Contreras-Porcia, Loretto; Meynard, Andres; Bulboa, Cristian; Vargas, Paulina; Rivas, Jorge; Latorre-Padilla, Nicolas; Navarrete, Sergio A.; Search, Francesca V.; Oyarzo-Miranda, Carolina; Toro-Mellado, Fernanda
    Heavy metals and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants that frequently cooccur in coastal environments. These contaminants can have negative impacts on the health and stability of marine and coastal ecosystems, affecting both the organisms themselves and the humans who consume them. A coastal industrial park in central Chile, housing a coal thermal power plant and other industrial activities, contributes to such pollution of coastal waters; however, neither the spatial alongshore distribution of heavy metals and PAHs, nor an assessment of their ecological effects on the biota have been systematically documented to date. In this paper, we present evidence regarding the direct negative effect of contamination by heavy metals and PAHs on the early life stages of kelps-being extremely harmful to their population persistence near highly polluted sites-as well as the indirect effects of their transference through the food web to higher trophic levels, leading to negative consequences for the feeding intake, growth, fertility, and larval development of marine herbivores that consume the contaminated seaweed. Likewise, the dispersion of contaminants by ocean currents can exacerbate the effects of pollution, having an adverse influence on marine ecosystem health even at sites far from the pollution source. Therefore, it is necessary to investigate the distribution patterns and extent of pollution along the coast to understand the impact of heavy metals and PAHs pollution on seaweed populations and the food web. It is considered critical for the development of effective environmental policies and regulations to protect these ecosystems and the people who depend on them.
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    Morphological and Molecular Identification of Ulva spp. (Ulvophyceae; Chlorophyta) from Algarrobo Bay, Chile: Understanding the Composition of Green Tides
    (2024) Mutizabal-Aros, Javiera; Ramirez, Maria Eliana; Haye, Pilar A.; Meynard, Andres; Pinilla-Rojas, Benjamin; Nunez, Alejandra; Latorre-Padilla, Nicolas; Search, Francesca V.; Tapia, Fabian J.; Saldias, Gonzalo S.; Navarrete, Sergio A.; Contreras-Porcia, Loretto
    Green algae blooms of the genus Ulva are occurring globally and are primarily attributed to anthropogenic factors. At Los Tubos beach in Algarrobo Bay along the central Chilean coast, there have been blooms of these algae that persist almost year-round over the past 20 years, leading to environmental, economic, and social issues that affect the local government and communities. The objective of this study was to characterize the species that form these green tides based on a combination of ecological, morpho-anatomical, and molecular information. For this purpose, seasonal surveys of beached algal fronds were conducted between 2021 and 2022. Subsequently, the sampled algae were analyzed morphologically and phylogenetically using the molecular markers ITS1 and tufA, allowing for the identification of at least five taxa. Of these five taxa, three (U. stenophylloides, U. uncialis, U. australis) have laminar, foliose, and distromatic morphology, while the other two (U. compressa, U. aragoensis) have tubular, filamentous, and monostromatic fronds. Intertidal surveys showed that U. stenophylloides showed the highest relative coverage throughout the seasons and all intertidal levels, followed by U. uncialis. Therefore, we can establish that the green tides on the coast of Algarrobo in Chile are multispecific, with differences in relative abundance during different seasons and across the intertidal zone, opening opportunities for diverse future studies, ranging from ecology to algal biotechnology.
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    Reporte legislativo No. 4 Legislatura 372 / 11 de Marzo 2024-10 de Marzo 2025. Observatorio de Políticas Públicas. Legislación relevante en pesca artesanal, acuicultura y desarrollo costero
    (Instituto Milenio en Socio-Ecología Costera SECO, 2025) Reyes Mendy, Francisca; Muñoz Godoy, Nicolás; Gelcich, Stefan; Haye, Pilar; Barra, Ricardo; Broitman, Bernardo; Contreras-Porcia, Loretto; Estévez, Rodrigo; Farías, Laura; Martínez, Carolina; Oyarzún, Fernanda; Reyes, Francisca; Vargas, Cristian; Vásquez, Felipe; Reyes Mendy, Francisca; Muñoz Godoy, Nicolás; Instituto Milenio en Socio-Ecología Costera SECO
    Este reporte del Observatorio de Políticas Públicas de SECOS analiza el trabajo legislativo relevante para la pesca artesanal, acuicultura y desarrollo costero en la legislatura 372. Se ingresaron 19 proyectos de ley, destacando la reforma a la Ley de Pesca (boletín 17095-21), normativas sobre buceo y transferencia tecnológica. Se votaron 11 proyectos y se promulgaron 3 leyes, incluyendo avances en equidad de género. Con más de 75 sesiones y 774 invitados en la Comisión de Pesca, se confirma la magnitud del debate sobre la nueva Ley de Pesca. La diversidad de temas tratados en los proyectos aprobados resalta la importancia del seguimiento legislativo y la participación informada en estos procesos.
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    Response to oxidative stress induced by high light and carbon dioxide (CO2) in the biodiesel producer model Nannochloropsis salina (Ochrophyta, Eustigmatales)
    (2015) Yangueez, Karen; Lovazzano, Carlos; Contreras-Porcia, Loretto; Ehrenfeld, Nicole
    Due to overconsumption of fossil fuels, microalgae have arrived as an alternative source of biofuel. Looking forward to generate a sustainable process, it is proposed to couple the cultures to CO2 emission sources, reaching in this way higher biomass performance and helping in the way with the capture of carbon released by the combustion processes. Nannochloropsis salina is a microalgae from the Monodopsidaceae family, which is easy to grow and produces high value compounds like essential pigments, polyunsaturated fatty acids and high amounts of lipids. Previous studies showed that adding CO2 to cultures (until 2%) generated an increment in biomass and in the production of fatty acids. However, these conditions also induce acidification of the media, a condition that may promote the generation of oxygen reactive species. In this work, the antioxidant performance of N. salina was studied under different culture conditions involving CO2 through 3 different approaches: analysis of antioxidant enzymatic activities (catalase, ascorbate peroxidase and peroxiredoxine), analysis of gene expression and the quantification of H2O2, phenolic compounds and lipoperoxides (e.g., cell damage marker). The results obtained suggest that an increase in the CO 2 concentration in the cultures (15,000 ppm), together with high light (1,000 mu mol m(-1) s(-1)) induces an oxidative stress condition in N. salina cells. However, the antioxidant response observed in the microalgae manages to soften this stress, adapting themselves to these conditions without affecting their global performance.
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    Seaweeds early development: detrimental effects of desiccation and attenuation by algal extracts
    (2012) Contreras-Porcia, Loretto; Callejas, Sebastian; Thomas, Daniela; Sordet, Camille; Pohnert, Georg; Contreras, Anibal; Lafuente, Ana; Flores-Molina, Maria R.; Correa, Juan A.
    The effects of desiccation on the early development stages of Mazzaella laminarioides, Scytosiphon lomentaria and Lessonia nigrescens, algal species with different patterns of distribution across the intertidal zone, were examined in the laboratory. In addition, the protective effect against desiccation was evaluated using algal extracts, including those from Porphyra columbina, a macroalga tolerant to desiccation that lives in the uppermost part of the intertidal zone. Our results showed that M. laminarioides displayed the highest resistance to daily desiccation, followed by S. lomentaria, whereas L. nigrescens was the most susceptible. Spores from L. nigrescens exposed to desiccation, although being able to germinate, ceased further post-germination development. In addition, our results showed that all species exposed to extracts from desiccated P. columbina successfully completed their development and strongly suggest the occurrence of compounds with protective properties that help in attenuating the stress caused by desiccation. Finally, our results indicate that the magnitude of the effects generated by desiccation on the early algal development is related to the position of the species in the intertidal zone, and that the protective effects of P. columbina extracts reveal an exceptional metabolism of this species under desiccation stress.