CMIP5 and CMIP6 Model Projection Comparison for Hydrological Impacts Over North America

International audienceA warmer climate impacts streamflows and these changes need to be quantified to assess future risk, vulnerability, and to implement efficient adaptation measures. The climate simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), which have been the basis of most such assessments over the past decade, are being gradually superseded by the more recent Coupled Model Intercomparison Project Phase 6 (CMIP6). Our study portrays the added value of the CMIP6 ensemble over CMIP5 in a first North America wide comparison using 3,107 catchments. Results show a reduced spread of the CMIP6 ensemble compared to the CMIP5 ensemble for temperature and precipitation projections. In terms of flow indicators, the CMIP6 driven hydrological projections result in a smaller spread of future mean and high flow values, except for mountainous areas. Overall, we assess that the CMIP6 ensemble provides a narrower band of uncertainty of future climate projections, bringing more confidence for hydrological impact studies

Comparison of the anti-inflammatory and immunomodulatory mechanisms of two medicinal herbs: meadowsweet (Filipendula ulmaria) and harpagophytum (Harpagophytum procumbens).

International audienceBackground: Meadowsweet (Filipendula ulmaria) and Harpagophytum (H. procumbens) are two medicinal herbs traditionally used for their anti-inflammatory effect. Nonetheless, if the effects of the single compounds isolated from these plants have been well described, little is known about the molecular mechanisms behind whole extracts.Methods: We studied and compared the effects of methanolic extracts from the aerial parts of F. ulmaria (FUE) and from the roots of H. procumbens (HPE) on different markers of inflammation such as antioxidant capacity, leukocyte ROS production, COX-2/PGE2 pathway or cytokine secretions.Results: FUE proved to be better than HPE in terms of antioxidant capabilities. Even if their effect on COX-2/PGE2 were similar, we found that their immune-modulatory activities were quite different. In the basal state, the FUE favored cytokines associated with Th1 lymphocytes whereas the HPE decreased the secretion of IL-21 and IL-23, associated with Th17 cells. In PHA-stimulated cells, the HPE increased the characteristic cytokines of Th1 cells, whereas the effects of the FUE were more nuanced.Conclusion: Though both plants are known as anti-inflammatory herbs, these results suggested that, apart from their similar anti-inflammatory effect on COX-2/PGE2, both could improve neutrophil and monocyte recruitment, as well as monocytes/macrophages and Th1, and presumably Th17, activation. Therefore, their impact on immune response was more likely immunostimulant

In Vitro Anti-Inflammatory and Immunomodulatory Activities of an Extract from the Roots of Bupleurum rotundifolium

This article belongs to the Special Issue Biological Potential and Medical Use of Natural ExtractsInternational audienceBackground: Some Bupleurum species, such as the Bupleurum chinense DC. or the Bupleurum scorzonerifolium Willd have been extensively studied (especially their roots) for the treatment of inflammation. In contrast, only compounds extracted from the aerial parts of Bupleurum rotundifolium have been studied and showed anti-inflammatory or antiproliferative activities. This study was conducted to investigate the antioxidant, anti-inflammatory, and immunomodulatory effects of Bupleurum rotundifolium roots. Methods: To tackle the various aspects of inflammation, we studied in vitro a methanolic extract from the roots of Bupleurum rotundifolium on peripheral blood mononuclear cells (PBMCs), polymorphonuclear neutrophils (PMNs), and the monocytic cells THP-1. Its antioxidant capacities and iron-chelating activity were assessed. The extract was tested on THP-1 differentiation, reactive oxygen species (ROS) production by leukocytes, neutrophils chemotaxis, cytokines, PGE2 production, and NF-κB activation in PBMCs. Results: The extract showed a decreased ROS production in stimulated cells. It increased PBMC chemokine secretion and up-regulated the differentiation of THP-1 monocytes into macrophage-like cells, indicating a potential interest of the extract in the resolution of acute inflammation. In addition, the analysis of cytokine production suggests that Bupleurum rotundifolium has immunomodulatory properties. Conclusions: Cytokines secretion, especially IL-1β and IL-12p70, provided us with a set of indicators suggesting that the extract might be able to drive the polarization of macrophages and lymphocytes toward a Th2 anti-inflammatory profile in excessive inflammation