Bioherbicide from Azadirachta indica Seed Waste: Exploitation, Efficient Extraction of Neem Oil and Allelopathic Effect on Senna occidentalis

"Bioherbicides are an alternative to minimize the damage caused to the environment using agrochemicals. This study had the objective of extracting neem oil from ripe waste fruits that Azadirachta indica A. Juss and optimizing the process using solvents (or a mixture of solvents) with different polarities. Then, through a solid-liquid extraction system (Soxhlet), the solvents hexane, methanol/hexane (1:1), ethanol, and hexane/ethanol (1:1) were used to determine the process with the highest yield and most efficiency. The physicochemical parameters of the extracted oil (density, acidity value, iodine value, saponification value, esters value, and molecular weight) and the % of free fatty acids were determined. In addition, the allelopathic properties of the oil (0%, 2%, 3%, and 4% m/v) on septic weed Senna occidentalis seeds were evaluated, analyzing their growth and development parameters (germination, germination speed, hypocotyl, and radicle length). Hexane was the most efficient (4 h) in neem oil extraction, with the highest yield (43%). It also provided a better oleic and linoleic acid content (41.3% and 18.6%), similar to ethanol extraction (41.1% and 20.22%). Moreover, the allelopathic properties were more prominent for the oils extracted with hexane and hexane/ethanol. This optimized process provides an efficient alternative to obtain a natural herbicidal potential for strategically controlling harmful plants

Bioherbicide from Azadirachta indica Seed Waste: Exploitation, Efficient Extraction of Neem Oil and Allelopathic Effect on Senna occidentalis

"Bioherbicides are an alternative to minimize the damage caused to the environment using agrochemicals. This study had the objective of extracting neem oil from ripe waste fruits that Azadirachta indica A. Juss and optimizing the process using solvents (or a mixture of solvents) with different polarities. Then, through a solid-liquid extraction system (Soxhlet), the solvents hexane, methanol/hexane (1:1), ethanol, and hexane/ethanol (1:1) were used to determine the process with the highest yield and most efficiency. The physicochemical parameters of the extracted oil (density, acidity value, iodine value, saponification value, esters value, and molecular weight) and the % of free fatty acids were determined. In addition, the allelopathic properties of the oil (0%, 2%, 3%, and 4% m/v) on septic weed Senna occidentalis seeds were evaluated, analyzing their growth and development parameters (germination, germination speed, hypocotyl, and radicle length). Hexane was the most efficient (4 h) in neem oil extraction, with the highest yield (43%). It also provided a better oleic and linoleic acid content (41.3% and 18.6%), similar to ethanol extraction (41.1% and 20.22%). Moreover, the allelopathic properties were more prominent for the oils extracted with hexane and hexane/ethanol. This optimized process provides an efficient alternative to obtain a natural herbicidal potential for strategically controlling harmful plants

Iron compound of pharmacological interest: evaluation of stability, toxicity against aquatic organisms, transport in cells and capacity to generate labile iron pool

A sobrecarga de ferro é uma condição desfavorável tanto para humanos (portadores de disfunções no metabolismo desse metal, ou submetidos a intensos regimes de transfusão) como, possivelmente, para os organismos aquáticos. Metalofármacos de ferro compreendem agentes anti-hipertensivos, anti-microbianos e suplementos minerais; mais recentemente, o uso de nanomateriais magnéticos à base de ferro vem sendo proposto para diversas aplicações clínicas ou farmacológicas. Contudo, os possíveis danos por sobrecarga induzida desses compostos não são totalmente compreendidos tanto para humanos e no ambiente aquático. Neste trabalho se usaram fármacos comerciais com diferentes revestimentos, de uso animal e humano, obtidos de diferentes indústrias brasileiras. Também se sintetizaram derivados de ferroceno (Fc) (TMH-Fc, TMH2-Fc), e nanopartículas magnéticas solúveis em água de três tamanhos (5,8,12 nm) pelo método de decomposição térmica a partir do Fe(acac)3. Em seguida, se avaliou a estabilidade dos metalofármacos de ferro em meios fisiologicamente relevantes, frente a sideróforos e/ou moléculas envolvidas no transporte do metal (CAL, Fl-Tf, Fl-DFO), mostrando disponibilidade de ferro só para os derivados de Fc a pH 7,4. A capacidade de geração de espécies reativas de oxigênio, medida por oxidação da DHR, foi detectada só para os derivados de Fc e nanomaterias. Um teste de toxicidade em Artemia salina de primeiro estágio foi positivo para o TMH-Fc (LC50 76,7 µM). Finalmente se estudou a capacidade de estocagem de ferro em células epiteliais de hepatopâncreas do caranguejo de mangue Ucides cordatus, em diferentes etapas de desenvolvimento (E, R, F e B). Todas mostraram transporte de metalofármacos e nanomaterias, e só os tipos celulares F e B incorporaram os derivados de Fc. Vários dos compostos de ferro estudados, com aplicações principalmente farmacológicas, poderiam ser disponibilizados no meio ambiente, principalmente no aquático. Os nossos resultados mostram que a capacidade de disponibilizar ferro e de gerar EROs podem ser quantificadas eficazmente por métodos de fluorescência. Além disso, sua possível toxicidade pode ser monitorada no meio marinho por bioindicadores de toxicidade e de acúmulo de metais.Iron overload is an unfavorable condition for both humans (patients with disorders in the metabolism of the metal, or subjected to intense transfusion) and possibly to aquatic organisms. Iron metallodrugs include antihypertensive agents, antimicrobial and mineral supplements. More recently, the use of magnetic iron based nanomaterials has been proposed for various clinical or pharmacological applications. However, possible overload damage induced by these compounds is not fully understood for both humans and aquatic organisms. For this work, we used commercial drugs with different coatings, for animal and human use, obtained from different Brazilian industries. Also we synthesized ferrocene (Fc) derivatives (TMH-Fc TMH2-Fc) and water soluble magnetic nanoparticles in three different sizes (5,8,12 nm) by the thermal decomposition method from Fe(acac)3. We evaluated the stability of iron metallodrugs in physiologically relevant medium against siderophores and/or molecules involved in metal transport (CAL, Fl-Tf, Fl-DFO), where we found iron availability only for ferrocene derivatives at pH 7.4. The ability to generate reactive oxygen species was measured by oxidation of DHR, and was present in the ferrocene derivative and nanomaterials. A toxicity assay on first stage Artemia salina was positive for TMH-Fc (LC50 76.7 µM). Finally, we studied the iron storage capacity of hepatopancreatic cells of a mangrove crab, Ucides cordatus, at different stages of development (E, R, F and B). All displayed transport of metallodrugs and nanomaterials, and only the cell types F and B incorporated ferrocene derivatives. Several of the iron compounds studied, particularly of pharmaceutical application, could be made available in the environment, especially in water. Our results show that the ability to supply iron and to generate ROS can be effectively quantified by fluorescence methods. In addition, their possible toxicity can be monitored in the marine environment with biomarkers of toxicity and accumulation of metals

Effect of Diet on Growth Performance of First Crab Stage <i>Callinectes sapidus</i> Rathbun, 1896 (Brachyura: Portunidae): A Comparison of Three Different Regimens

This study aimed to supply three foods to the crab Callinectes sapidus in its juvenile stage and compare their effects on its growth. For that, crab larvae were cultured from oviparous adult female crabs. The larvae (z1–z8) were fed with rotifers, previously cultured with microalgae and megalopae (Meg.) with live Artemia salina larvae, obtained from fresh cysts until they reached juvenile development (c1, first crab). Then, 270 animals (c1) were analyzed in three groups of 90, with different diets: shrimp (Penaeus vannamei; Group 1), squid (Mastigoteuthis flammea; Group 2), and tilapia fish (Oreochromis niloticus; Group 3). After 90 days of feeding regimens, the sizes of juvenile crabs were measured by microscopy, and the following relationship was found (p Group 2 (14.5 ± 0.9) > Group 3 (10.4 ± 0.6). The nutritional factor played an essential role in this size differentiation. This intelligent and differentiated feeding strategy showed us that shrimp could be an essential source for the growth of crabs in the juvenile stage. This new approach to safe and efficient roost feeding can classify crabs by size for further hormonal, molting, and reproductive studies

HSP70 in Gills and Hepatopancreas of Mangrove Crabs <i>Ucides cordatus</i>: Comparison between Contaminated and Pristine Environments

This study analyzed field and acclimatized (7 days) mangrove Ucides cordatus crabs from polluted and unpolluted environments to compare their HSP70 levels. The animals were cryo-anesthetized and dissected. Gills (anterior and posterior) and hepatopancreas were collected to evaluate total proteins and HSP70 levels using ELISA (Enzyme-Linked Immunosorbent Assay) method. The acclimatized animals from polluted environments showed higher HSP70 levels in the hepatopancreas than field animals. Results showed higher HSP70 levels in laboratory animals from the polluted environment than in field animals in the posterior gills. The regulation to decrease the damage caused by the environment and the acclimatization process may not be sufficient to stabilize physiological responses, especially in animals from polluted environments

Workshop como uma metodologia para o ensino-aprendizagem de ciências: um estudo de caso com o grupo Bioinorganic Chemistry Environment and Medicine (BIOMET)

The search for educational methodologies, such as workshops, is constant to improve the teaching-learning process. Thus, the objective of the study was to analyze the BIOMET 2017 workshop as a scientific dissemination event and methodological tool for the participants' significant learning. The event took place in 3 days, with the first theoretical day (lectures on marine bioindicators), the second practical (mini-course) and the third day of data analysis and discussion. At the end of the third day, a satisfaction form was given to each participant to evaluate the event. In general, the event featured a large male participation of undergraduate students, from the areas of Chemistry and Biology, with little experience in the laboratory, and classified as “good or very good” by the participants. The mini-course statistically evaluated the death of fairy shrimp, over time, in increasing concentrations of cadmium chloride. The death of fairy shrimp occurred after 10 mmol L-1, after 1 h of the experiment, which contrasted with the literature, possibly due to the difficulties related to the execution of the experiment. To that end, events as BIOMET 2017 are important tools for improvement, bringing theoretical content closer to laboratory practice, developing more critical and reflective professionalsA busca por metodologias educacionais, como os workshops, é constante para a melhoria do processo de ensino-aprendizagem. Dessa maneira, o objetivo do estudo foi analisar o workshop BIOMET 2017 como um evento de difusão científica e ferramenta metodológica para o aprendizado significativo dos participantes. O evento ocorreu em 3 dias, sendo o primeiro dia teórico (palestras sobre bioindicadores marinhos), o segundo prático (minicurso) e o terceiro dia de análise e discussão de dados. Ao final do terceiro dia, um formulário de satisfação foi dado para cada participante para avaliação do evento. De maneira geral, o evento apresentou grande participação masculina de estudantes de graduação, das áreas de Química e Biologia, com pouca experiência em laboratório, e classificado como “bom ou muito bom” pelos participantes. O minicurso avaliou estatisticamente a morte de artêmias, ao longo do tempo, em crescentes concentrações de cloreto de cádmio. A morte de artêmias ocorreu a partir de 10 mmol L-1, após 1 hora de experimento, os quais contrastaram com a literatura, possivelmente devido às dificuldades relacionadas a execução do experimento. Com esse intuito, eventos como BIOMET 2017 são importantes ferramentas de aprimoração, aproximando o conteúdo teórico da prática laboratorial, desenvolvendo profissionais mais críticos e reflexivos.Palavras chave: Educação, minicurso, artêmias, contaminantes

Iron metallodrugs: stability, redox activity and toxicity against Artemia salina.

Iron metallodrugs comprise mineral supplements, anti-hypertensive agents and, more recently, magnetic nanomaterials, with both therapeutic and diagnostic roles. As biologically-active metal compounds, concern has been raised regarding the impact of these compounds when emitted to the environment and associated ecotoxicological effects for the fauna. In this work we assessed the relative stability of several iron compounds (supplements based on glucoheptonate, dextran or glycinate, as well as 3,5,5-trimethylhexanoyl (TMH) derivatives of ferrocene) against high affinity models of biological binding, calcein and aprotransferrin, via a fluorimetric method. Also, the redox-activity of each compound was determined in a physiologically relevant medium. Toxicity toward Artemia salina at different developmental stages was measured, as well as the amount of lipid peroxidation. Our results show that polymer-coated iron metallodrugs are stable, non-redox-active and non-toxic at the concentrations studied (up to 300 µM). However, TMH derivatives of ferrocene were less stable and more redox-active than the parent compound, and TMH-ferrocene displayed toxicity and lipid peroxidation to A. salina, unlike the other compounds. Our results indicate that iron metallodrugs based on polymer coating do not present direct toxicity at low levels of emission; however other iron species (eg. metallocenes), may be deleterious for aquatic organisms. We suggest that ecotoxicity depends more on metal speciation than on the total amount of metal present in the metallodrugs. Future studies with discarded metallodrugs should consider the chemical speciation of the metal present in the composition of the drug

Concentrations (μM) and percentage of redox-active iron (%) in samples of Fc derivatives (average ± s.d. of 8 measurements).

<p>Total iron concentration = 40 μM.</p><p>^a (p < 0.05)</p><p>^b (p < 0.05)</p><p>^c (p < 0.05)</p><p>Concentrations (μM) and percentage of redox-active iron (%) in samples of Fc derivatives (average ± s.d. of 8 measurements).</p

Dose-response curves for adult or stage 1 <i>Artemia</i> treated with ferrocene and its derivatives.

<p>Effects of Fc (in adults) and TMH-Fc (in stage 1 animals) were statistically different (*, P < 0.05).</p

Quenching of 2 μM calcein in (A) HBS or (B) artificial seawater, and of 2 μM Fl-Tf in (C) HBS or (D) artificial seawater, caused by Fc derivatives.

<p>(E) Percentage of iron available to these probes (chelatable iron), calculated at the highest Fe concentration (2 μM). Rel. un. = relative fluorescence units.</p