Native palm trees fruit from the Amazonian rainforest, Oenocarpus bacaba and Oenocarpus bataua, are very often used in the diet of local communities, but the biological activities of their roots and leaflets remain poorly known. Total phenolic content (TPC) and antioxidant activity of root and leaflet extracts from Oenocarpus bacaba and Oenocarpus bataua were assessed by using different chemical assays, the oxygèn radical absorbance capacity (ORAC), the 2,2-diphenyl-l-picrylhydrazyl (DPPH) free radical-scavenging capacity and the ferric-reducing ability of plasma (FRAP). Cellular antioxidant activity and cytotoxicity were also measured in Normal Human Dermal Fibroblasts. The polyphenolic composition of Oenocarpus extracts was investigated by LC-MSn. Oenocarpus leaflet extracts were more antioxidant than root extracts, being at least as potent as Euterpe oleracea berries known as superfruit. Oenocarpus root extracts were characterized by hydroxycinnamic acids (caffeoylquinic and caffeoylshikimic acids), while leaflet extracts contained mainly caffeoylquinic acids and C-glycosyl flavones. These results suggest that leaflets of both Oenocarpus species could be valorized as a new non-cytotoxic source of antioxidants from Amazonia, containing hydroxycinnamic acids and flavonoids, in the pharmaceutical, cosmetic or agri-food industry.

BackgroundA major requirement for malaria elimination is the development of transmission-blocking interventions. In vitro transmission-blocking bioassays currently mostly rely on the use of very few Plasmodium falciparum reference laboratory strains isolated decades ago. To fill a piece of the gap between laboratory experimental models and natural systems, the purpose of this work was to determine if culture-adapted field isolates of P. falciparum are suitable for in vitro transmission-blocking bioassays targeting functional maturity of male gametocytes: exflagellation.MethodsPlasmodium falciparum isolates were adapted to in vitro culture before being used for in vitro gametocyte production. Maturation was assessed by microscopic observation of gametocyte morphology over time of culture and the functional viability of male gametocytes was assessed by microscopic counting of exflagellating gametocytes. Suitability for in vitro exflagellation-blocking bioassays was determined using dihydroartemisinin and methylene blue.ResultsIn vitro gametocyte production was achieved using two isolates from French Guiana and two isolates from Cambodia. Functional maturity of male gametocytes was assessed by exflagellation observations and all four isolates could be used in exflagellation-blocking bioassays with adequate response to methylene blue and dihydroartemisinin.ConclusionThis work shows that in vitro culture-adapted P. falciparum field isolates of different genetic background, from South America and Southeast Asia, can successfully be used for bioassays targeting the male gametocyte to gamete transition, exflagellation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0752-x) contains supplementary material, which is available to authorized users.

Many stimuli such as hormones and stress factors elicit changes in intracellular calcium content that serve to convey information and activate appropriate responses. 1 These Ca 2+ signals are perceived by different Ca 2+ sensors, and calmodulin (CaM) is one of the best characterized Ca 2+ sensors in eukaryotes. Calmodulinlike (CML) proteins extend the Ca 2+ -toolkit in plants; CMLs share sequence similarity with the ubiquitous and highly conserved CaM, however, except for some of them, their roles at physiological and molecular levels remain largely unknown. 2,3In our group, we reported data on Arabidopsis thaliana CML9 that exhibits 46% amino acid sequence identity with CaM. 4,5 We showed that CML9 transcripts are found in all organs and that CML9 gene is rapidly induced by both abiotic and biotic stress. In a recent publication in Plant Journal, we demonstrated that CML9 expression is also rapidly induced by the phytopathogenic bacteria Pseudomonas syringae pv tomato DC3000 (Pst DC3000) 4 and that this upregulation belongs to salicylic acid (SA) production and to the flagellin perception receptor FLS2. Moreover, exogenous applications of SA or flg22, the biological active peptide of flagellin, are also able to induce rapid and transient CML9 gene expression and using a reverse genetic approach, we established that CML9 participates in plant innate immunity through a flagellin-dependent signaling pathway. 4 In addition to mediate plant innate immunity, flagellin and flg22 are also known to inhibit root elongation and seedling growth.6 Thus, we explored this facet of flagellin effect and we bring here new informations on plant growth behavior of CML9 overexpressing and knockout lines upon flg22 treatments and Plants have evolved complex signaling networks to respond to their fluctuating environment and adapt their growth and development. Calcium-dependent signaling pathways play key role in the onset of these adaptive responses. in plant cells, the intracellular calcium transients are triggered by numerous stimuli and it is supposed that the large repertory of calcium sensors present in higher plants could contribute to integrate these signals in physiological responses. here, we present data on CmL9, a calmodulin-like protein that appears to be involved in plant responses to both biotic and abiotic stress. using a reverse genetic approach based on gain and loss of function mutants, we present here data indicating that this CmL might also be involved in root growth control in response to the flagellin, a pathogen-associated molecular pattern (PamP) also involved in plant immunity. Keywords: Calmodulin-like protein, Arabidopsis thaliana, root growth, flagellin, gibberellins discuss the possible involvement of CML9 in plant growth control through hormonal compounds. CML9, a multifunctional The cml9 Genotypes Exhibit Altered Responses to FlagellinAs previously showed, cml9 mutants or CML9 overexpressors exhibit respectively an enhanced susceptibility and a better resistance against phytopathogenic bacteria. 4 Using...