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The in vivo efficacy of potential antimalarials is usually evaluated by direct microscopic determination of the parasitaemia of Plasmodium-infected mice on Giemsa-stained blood smears. This process is time-consuming, requires experienced technicians and is not automatable. Therefore, we optimized a SYBR Green I (SYBRG I) fluorescence-based assay to fluorometers commonly available in many research laboratories. This technique was originally developed to assess parasitaemia in humans by cytometry. We defined optimal conditions with Plasmodium berghei-infected mice, standard lysis buffer (Tris, EDTA, saponin and Triton), whole blood cells and 2 h staining incubation with SYBRG I 2X. The fluorescence background generated by uninfected whole blood cells was low (around 4.6%), and the linearity high (r = 0.96), with parasitaemia ranging from 1.4 to 60%. The Bland-Altman plot showed a strong correlation between SYBRG I and Giemsa gold standard method; Z'-factor was>0.5. These findings suggest that our fluorescence-based assay is suitable for in vivo antimalarial drug assessment in a malaria murine model. It can help to overcome the human bias found with microscopic techniques.

Background The chagra is the agroforestry system adapted to the characteristics of the Amazon region. Recently, there has been a reported loss of biodiversity and traditional knowledge associated with the chagras. This paper characterizes the cultivators, exploring knowledge and expressed value perception in the context of the Amazonian chagra of an indigenous community; also, this prioritizes species, under the optics of commercial opportunity. Methods A semi-structured instrument was applied to 14 volunteers, asking about marketing preferences and use values of the species; later, a floristic inventory and prioritization workshop was developed. Results Sixty-two percent of the participants were 50 years or older at the time of the interview. Open conversations showed that traditional knowledge is a matter of practice; and is maintained mainly by the older "grandfathers". Thirty-eight species, belonging to 28 different families, were reported, showing considerable diversity. Seventy-nine percent of the participants consider the Leticia market and sales to tourists as the main marketing scenarios. Conclusions The Ziora-Amena community centralizes the handling of chagras in the community's older adults, who transmit their traditional knowledge to new generations through oral tradition. Indicators of preference, use, and abundance highlight the food species. The perception of the trade stakeholder encourages research and development of endemic species, with health properties or ingredients for industry, which represent an opportunity of high added value for the region.

Background: Malaria, babesiosis, trypanosomosis, and leishmaniasis are among the most life-threating parasites, but the range of drugs to treat them is limited. It is then urgent to have an effective, safe drug with a large spectrum of activity at a low cost.Methods: For this purpose, an aryl amino alcohol derivative called Alsinol was resynthesized, screened in silico and tested against Plasmodium, Babesia, Trypanosoma, and Leishmania.Results: Alsinol was easy to synthesize, following the Lipinski and Ghose rules calculated in silico. It had schizontocidal activity against P. falciparum and was able to inhibit gametocytogenesis, being particularly active against late gametocytes in vitro. On malariainfected mice, it showed a dose-dependent activity similar to chloroquine. It was also as active as reference compounds against B. divergens, and against promastigotes and amastigotes stages of Leishmania in vitro. It also inhibited the in vitro growth of two African animal strains of Trypanosoma but was ineffective in vivo in our experimental conditions. It showed acceptable toxicity in J774A1 and Vero cells models. Conclusion:Alsinol is inexpensive to produce, has a large spectrum of activity with an interesting toxicity index. Nevertheless, crucial challenges remain to be faced: the description of a suitable clinical formulation and the determination of the safety margin in preclinical models.