Evaluation of the antimicrobial activity of silver nanoparticles biosynthesized from the aqueous extract of Schinus terebinthifolius Raddi leaves.

Silver nanoparticles (AgNPs) synthesized from green synthesis using medicinal plants are presented as an option for the development of new antimicrobial agents. In this context, this study aims to evaluate the antimicrobial activity of silver nanoparticles synthesized from the aqueous extract of Schinus terebinthifolius Raddi leaves, popularly known as "aroeira." A 23 factorial design was used to assess the statistical significance of the studied factors, and Box-Behnken design was used to define the optimal conditions for the green synthesis of AgNPs. The studied factors were significant for the synthesis of nanoparticles, and the optimal conditions were pH 9.5, reaction time of 180 min, and 10 g of S. terebinthifolius Raddi leaves. The samples were characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and dynamic light scattering. Antimicrobial activity was evaluated using the broth microdilution method and through the minimum microbicidal concentration. AgNPs showed greater antimicrobial efficacy compared to the extract, both for bacteria and fungi: bacteriostatic activity against all tested bacteria and bactericidal against Pseudomonas aeruginosa, besides fungistatic action against Candida albicans and Candida glabrata. Finally, the aqueous extract of "aroeira" leaves was effective in the synthesis of AgNPs, with greater antimicrobial potential than the extract.

An overview of the environmental applicability of vermicompost: from wastewater treatment to the development of sensitive analytical methods.

The use of vermicompost (humified material) for treating wastewaters, remediating polluted soils, improving agricultural productivity, protecting crop production, and developing sensitive analytical methods is reviewed here, covering the past 17 years. The main advantages of vermicompost, considering all applications covered in this paper, comprise (i) easy acquisition, (ii) low costs, (iii) structural, chemical, and biological characteristics responsible for exceptional adsorptive capacities as well as pollutant degradation, and (iv) the promotion of biocontrol. Specifically, for wastewater decontamination, a considerable number of works have verified the adsorption of toxic metals, but the application of vermicompost is still scarce for the retention of organic compounds. Problems related to the final disposal of enriched vermicompost (after treatment steps) are often found, in spite of some successful destinations such as organic fertilizer. For decontaminating soils, the use of vermicompost is quite scarce, mainly for inorganic pollutants. In agricultural productivity and biocontrol, vermicompost imparts remarkable benefits regarding soil aggregation, plant nutrition, and the development of beneficial microorganisms against phytopathogens. Finally, the use of vermicompost in sensitive analytical methods for quantifying toxic metals is the newest application of this adsorbent.

Antileshimania, anti-Trypanosoma cruzi and antimicrobial activities of scandenin and 4'-O-methylderrone from Deguelia costata.

Scandenin and 4'-O-methylderrone were isolated from the ethanol extract of the roots and dichloromethane extract of the leaves of Deguelia costata (Benth.) A.M.G. Azevedo & R.A. Camargo, respectively. These compounds and their extracts had their antiprotozoal, antibacterial, antifungal, and cytotoxic activities tested. All samples were active for amastigotes of the T. cruzi, with EC50 values varying from 34.5 to 9.8 µg mL-1. The 4'-O-methylderrone and scandenin showed better leishmanicidal action against the promastigote of L. amazonensis, with EC50 of 43.3 and 45.9 µg mL-1, respectively, when compared to their extracts. All extracts and scandenin showed activities against Staphylococcus sp, Bacillus sp, and Candida sp. The compounds did not show cytotoxicity on rat macrophages. As confirmed by spectroscopic analyses, the extracts are rich in phenolics, mainly isoflavonoids. The study of D. costata is a promising strategy for discovering isoflavones and 4-hydroxy-3-phenylcoumarins with antiprotozoal, antibacterial, and antifungal activities.