Nanobiopesticides: Are they the future of phytosanitary treatments in modern agriculture?

The world's population is continuously increasing; therefore, food availability will be one of the major concerns of our future. In addition to that, many practices and products used, such as pesticides and fertilizers have been shown harmful to the environment and human health and are assumed as being one of the main factors responsible for the loss of biodiversity. Also, climate change could agravate the problem since it causes unpredictable variation of local and regional climate conditions,which frequently favor the growth of diseases, pathogens and pest growth. The use of natural products, like essential oils, plant extracts, or substances of microbial-origin in combination with nanotechnology is one suitable way to outgrow this problem. The most often employed natural products in research studies to date include pyrethrum extract, neem oil, and various essential oils, which when enclosed shown increased resistance to environmental factors. They also demonstrated insecticidal, antibacterial, and fungicidal properties. However, in order to truly determine if these products, despite being natural, would be hazardous or not, testing in non-target organisms, which are rare, must start to become a common practice. Therefore, this review aims to present the existing literature concerning nanoformulations of biopesticides and a standard definition for nanobiopesticides, their synthesis methods and their possible ecotoxicological impacts, while discussing the regulatory aspects regarding their authorization and commercialization. As a result of this, you will find a critical analysis in this reading. The most obvious findings are that i) there are insufficient reliable ecotoxicological data for risk assessment purposes and to establish safety doses; and ii) the requirements for registration and authorization of these new products are not as straightforward as those for synthetic chemicals and take a lot of time, which is a major challenge/limitation in terms of the goals set by the Farm to Fork initiative.

Toxicity in vitro and in Zebrafish Embryonic Development of Gold Nanoparticles Biosynthesized Using Cystoseira Macroalgae Extracts.

INTRODUCTION: Research on gold nanoparticles (AuNPs) occupies a prominent place in the field of biomedicine nowadays, being their putative toxicity and bioactivity areas of major concern. The green synthesis of metallic nanoparticles using extracts from marine organisms allows the avoidance of hazardous production steps while maintaining features of interest, thus enabling the exploitation of their promising bioactivity. OBJECTIVE: To synthesize and characterize AuNPs using, for the first time, macroalga Cystoseira tamariscifolia aqueous extract (Au@CT). METHODS: Algal aqueous extracts were used for the synthesis of AuNPs, which were characterized using a wide panel of physicochemical techniques and biological assays. RESULTS: The characterization by UV-Vis spectroscopy, transmission electron microscopy, Z-potential and infrared spectroscopy confirmed that Au@CT were stable, spherical and polycrystalline, with a mean diameter of 7.6 ± 2.2 nm. The antioxidant capacity of the extract, prior to and after synthesis, was analyzed in vitro, showing that the high antioxidant potential was not lost during the synthesis. Subsequently, in vitro and in vivo toxicity was screened, by comparing two species of the genus Cystoseira (C. tamariscifolia and C. baccata) and the corresponding biosynthesized gold nanoparticles (Au@CT and Au@CB). Cytotoxicity was tested in mouse (L929) and human (BJ5ta) fibroblast cell lines. In both cases, only the highest (nominal) test concentration of both extracts (31.25 mg/mL) or Au@CB (12.5 mM) significantly affected cell viability, as measured by the MTT assay. These results were corroborated by a Fish Embryo Acute Toxicity (FET) test. Briefly, it was shown that, at the highest (nominal) tested concentration (31.25 mg/mL), CT extract induced significantly higher cytotoxicity and embryotoxicity than CB extract. However, it was demonstrated that Au@CT, but not Au@CB, were generally non-toxic. At sub-lethal (nominal) test concentrations (1.25 and 2.5 mM), Au@CT affected zebrafish embryonic development to a much lesser extent than Au@CB. In vitro wound healing assays also revealed that, while other experimental conditions did not impact cell migration, CT and Au@CT displayed a moderate positive effect. CONCLUSION: Au@CT and Au@CB display promising features, desirable for biomedical applications, as wound healing.

Disfunção erétil, hipertensão arterial e uso de anti-hipertensivos - Pesquisa ativa / Erectile disfunction, arterial hypertension and anti-hypertensives - Active research

Objetivo: Determinar a prevalência da disfunção erétil (DE) em pacientes com hipertensão arterial (HA) primária em tratamento medicamentoso e sua relação e análise do impacto psicossocial. Métodos: O estudo abordou homens hipertensos em tratamento medicamentoso e idade superior a 40 anos que foram avaliados segundo o Índice Internacional de Função Erétil (IIFE- 5), Escala de Ansiedade e Depressão e um questionário sobre sua opinião quanto à relação da DE com as medicações anti-hipertensivas. A dosagem da testosterona sérica foi usada para exclusão de causas orgânicas da DE. Os dados foram analisados visando identificar o coeficiente de correlação entre as varáveis. Resultados: Foi observada prevalência de DE em 74% dos pacientes e, destes, 43% referiram piora do desempenho sexual após uso crônico da medicação anti-hipertensiva. Não foi possível provar uma correlação direta entre o uso de anti-hipertensivos e a DE, entretanto observou-se aumento do coeficiente de correlação em função da progressão da idade dos pacientes. Os betabloqueadores mostraram maior coeficiente de correlação com a DE (25%), seguido dos inibidores da enzima conversora de angiotensina (19%). Dos pacientes, 43% foram classificados com provável diagnóstico de ansiedade ou depressão e 35% com possível diagnóstico. Conclusão: Foi possível inferir, mas não afirmar uma correlação entre DE, HA e o uso de anti-hipertensivos

Objective: To determine the prevalence of erectile dysfunction (ED) in patients with primary arterial hypertension (AH) undergoing drug treatment and its relationship and analysis of psychosocial impact. Methods: The study addressed hypertensive men on drug treatment and over 40 years of age who were evaluated according to the International Index of Erectile Function (IIFE-5), Anxiety and Depression Scale, and a questionnaire about their opinion regarding the relationship between ED and antihypertensive medications. Serum testosterone dosage was used to rule out the organic causes of ED. Data were analyzed to identify the correlation coefficient between variables. Results: Prevalence of ED was observed in 74% of patients and, of these, 43% reported worsened sexual performance after chronic use of antihypertensive medications. It was not possible to prove any direct correlation between the use of antihypertensive drugs and ED, however an increase in the correlation coefficient was observed as a function of patients' age progression. Beta-blockers showed higher correlation coefficient with ED (25%), followed by angiotensin-converting enzyme inhibitors (19%). 43% of patients were classified with probable diagnosis of anxiety or depression and 35% with possible diagnosis. Conclusion: It was possible to infer but not to affirm a correlation between DE, HA and the use of antihypertensive drugs