Dengue is a viral disease that affects about 50 million people per year around the world. The aim of this study was to investigate the larvicidal activity of Agave sisalana crude extract in order to develop a new insecticide against Aedes aegypti. In larvicidal activity assays, fourth-stage Ae. aegypti larvae were exposed to different concentrations of A. sisalana crude extract for 3, 6, 12, and 24 h for determining the LC50. Next, we explored its cytotoxic activity by flow cytometry. Furthermore, histological alterations were confirmed by histopathological analysis, and the nitric oxide (NO) production by hemocytes was checked after different periods of exposure to A. sisalana crude extract. The LC50 was 4.5 ± 0.07 mg/mL. In addition, flow cytometry revealed an increase of cellular necrosis (21 and 16.5 % after 12 and 24 h, respectively) in larvae that were exposed to A. sisalana crude extract. The histological analysis revealed cell lysis and destruction of the peritrophic membrane. Furthermore, there was a reduction in the concentration of NO in the hemolymph from larvae exposed to A. sisalana crude extract after 3, 6, and 24 h (5.3 ± 4.3 vs. 22.7 ± 5.2 μM, 4.3 ± 5.5 vs. 25.4 ± 6.6 μM, and 6 ± 1.7 vs. 37.1 ± 7.8 μM, respectively). Our findings show that A. sisalana crude extract constitutes an effective larvicidal agent against Ae. aegypti larvae due to its necrotizing activity in hemocytes and inhibition of the NO production.

In this study was evaluated the influence of the extraction factors on the extract's properties to improve the recovery of high concentrations of the phytochemicals important for the biological activities from pods of Libidibia ferrea (Mart. ex Tul.) L. P. Queiroz. The extracts were obtained by turbo-extraction and a factorial design 3 2 was used to study the importance of the drug amount (5, 10 or 15 g) and the solvent (Ethanol 40, 60 or 80%, v/v) on the variables of response, and the optimization was performed by Response Surface Methodology (RSM) and Desirability profile. Mathematical models were fitted according to experimental data and the validated equations were used to generate RSM for each dependent variable (dry residue; total polyphenol content; content of gallic acid and ellagic acid; and, efficiency of extraction). The factors studied within the applied experimental field presented different influence profiles for the responses, and significant interactions between linear and quadratic terms. The statistical analysis showed high R 2 > 0.99. The RSM and Desirability (> 0.95) allowed to show that the optimum conditions to produce extractive solutions of Libidibia ferrea with high efficiency for ellagic acid and gallic acid were 15 g and ethanol 40%.

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JOHNSON, Bryce G. et al. Uromodulin p.Cys147Trp mutation drives kidney disease by activating ER stress and apoptosis.