Studies on the Phytochemical Profile of Ocimum basilicum var. minimum (L.) Alef. Essential Oil, Its Larvicidal Activity and In Silico Interaction with Acetylcholinesterase against Aedes aegypti (Diptera: Culicidae).

Aedes aegypti L. (Diptera: Culicidae) is an important transmitter of diseases in tropical countries and controlling the larvae of this mosquito helps to reduce cases of diseases such as dengue, zika and chikungunya. Thus, the present study aimed to evaluate the larvicidal potential of the essential oil (EO) of Ocimum basilicum var. minimum (L.) Alef. The EO was extracted by stem distillation and the chemical composition was characterized by gas chromatography coupled with mass spectrometry (GC/MS and GC-FID). The larvicidal activity of EO was evaluated against third instar Ae. aegypti following World Health Organization (WHO) standard protocol and the interaction of the major compounds with the acetylcholinesterase (AChE) was evaluated by molecular docking. The predominant class was oxygenated monoterpenes with a concentration of 81.69% and the major compounds were limonene (9.5%), 1,8-cineole (14.23%), linalool (24.51%) and methyl chavicol (37.41%). The O. basilicum var. minimum EO showed unprecedented activity against third instar Ae. aegypti larvae at a dose-dependent relationship with LC50 of 69.91 (µg/mL) and LC90 of 200.62 (µg/mL), and the major compounds were able to interact with AChE in the Molecular Docking assay, indicating an ecological alternative for mosquito larvae control.

Biochar mitigates bioavailability and environmental risks of arsenic in gold mining tailings from the eastern Amazon.

Artisanal gold mining has generated tailings highly contaminated by arsenic (As) in Cachoeira do Piriá, eastern Amazon, leading to severe risks to the environment. Such risks should be mitigated considering the bioavailable concentration of the element, since it implies immediate damage to the ecosystem. The objective of this study was to evaluate the potential of biochars in mitigating the environmental risks of bioavailable As concentrations in gold mining tailings from underground and cyanidation exploration. The biochar addition increased mineral components, cation retention, phosphorus in all fractions, and organic and inorganic carbon. The bioavailability of As was reduced after adding the biochars, following the order palm kernel cake biochar > Brazil nut shell biochar > açaí seed biochar, with reductions of up to 13 mg kg-1 in the underground mining tailings and 17 mg kg-1 in the cyanidation mining tailings. These results contributed to the statistically significant reduction of the environmental risks in both mining tailings (6-17% in the underground mining tailings and 9-20% in the cyanidation mining tailings), which was emphasized by Pearson's correlation and multivariate analyzes. The incorporation of the bioavailable fractions of As (from sequential extraction) in the environmental risk assessment was a promising method for evaluating the efficiency of biochars in mitigating the damage caused by this metalloid in gold mining tailings.

Impact of copper mining wastes in the Amazon: Properties and risks to environment and human health.

Improper disposal of copper mining wastes can threaten the ecosystem and human health due to the high levels of potentially toxic elements released into the environment. The objective of this study was to determine the properties of Cu mining wastes generated in the eastern Amazon and their potential risks to environment and human health. Samples of forest soil and artisanal/industrial Cu mining wastes were collected and subjected to characterization of properties and pseudo-total concentrations of Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, and Zn, in addition to chemical fractionation of Cu. The pH ranged from near neutrality to alkaline. Pseudo-total concentrations of Cu were high in all wastes, mainly in the artisanal rock waste, with 19,034 mg kg-1, of which 61% is concentrated in the most reactive fractions. Pollution indices indicated that the wastes are highly contaminated by Cu and moderately contaminated by Cr and Ni. However, only the artisanal rock waste is associated with environmental risk. Non-carcinogenic and carcinogenic human health risks were detected, especially from exposure to Cr in the artisanal rock waste. Prevention actions and monitoring of the artisanal mining area are necessary to avoid impacts to the local population.

Plinia cauliflora (Mart.) Kausel: toxicological assays, biological activities, and elemental analysis of organic compounds.

Jaboticaba, Plinia cauliflora (Mart.) Kausel, is a Brazilian berry traditionally used in folk medicine as treatment for some health conditions. Phenolic compounds such as flavonoids and anthocyanins have previously been detected in the fruit. This current study aimed to evaluate the toxicological effects of jaboticaba peel extract (JPE) on Artemia salina, L929, and MDA-MB-231 cell lines. Besides, JPE antioxidant, acetylcholinesterase, and antifungal activities, and elemental analysis CHNS were also tested. JPE had moderate toxicity (LD50 = 360.92 µg mL-1) on A. salina, non-toxic effect on L929 cell line, and decreased the viability of cancer cell line MDA at 1,000 µg mL-1 and 500 µg mL-1 concentrations. The antioxidant activity toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) performed IC50 = 37.45 ± 0.17 µg mL-1, whereas 45.7% of acetylcholinesterase activity was inhibited. By its elemental composition, JPE is an alternative food supplement and dermocosmetic component. Antifungal potential toward Candida strains was not observed.

Phytoremediation potential of Khaya ivorensis and Cedrela fissilis in copper contaminated soil.

Mineral exploration of copper (Cu) in the Amazon has significantly impacted the environment, leading to contamination of large areas that require remediation. Tropical tree species that can immobilize metals and restore plant cover should be selected for phytoremediation programs. The phytoremediation behavior of Khaya ivorensis and Cedrela fissilis was studied in Cu contaminated soil (60, 200, 400, and 600 mg kg-1). K. ivorensis absorbed extremely high amounts of Cu in the roots (329 mg kg-1) and excessive amounts in the shoot (52 mg kg-1), while maintaining similar growth to control plants. C. fissilis seedlings presented a higher Dickson quality index. Bioaccumulation (BCF) and translocation (TF) factors were low in both species, indicating that even with the high amounts of copper absorbed, these contents were lower than the soil concentration (BCF < 1) and that most of Cu was compartmentalized in the roots (TF < 1). The tolerance index of K. ivorensis (>1) and C. fissilis (~1) indicate their ability to grow in Cu contaminated soil. These results suggest that these species could potentially be used as phytoremediators.

Environmental and human health risks of arsenic in gold mining areas in the eastern Amazon.

Knowledge of arsenic (As) levels in gold (Au) mining areas in the Amazon is critical for determining environmental risks and the health of the local population, mainly because this region has the largest mineral potential in Brazil and one of the largest in the world. The objective of this study was to assess the environmental and human health risks of As in tailings from Au exploration in the eastern Amazon. Samples were collected from soils and tailings from different exploration forms from 25 points, and the total concentration, pollution indexes and human health risk were determined. Concentrations of As were very high in all exploration areas, especially in tailings, whose maximum value reached 10,000 mg kg-1, far above the investigation value established by the Brazilian National Council of the Environment, characterizing a polluted area with high environmental risk. Exposure based on the daily intake of As demonstrated a high health risk for children and adults, whose non-carcinogenic risk indexes of 17.8, extremely above the acceptable limit (1.0) established by the United States Environmental Protection Agency. High levels of As in reactive fractions in underground, cyanidation, and colluvium mining areas, as well as extremely high gastric and intestinal bioaccessibility were found, suggesting that high levels may be absorbed by the local population. The results show that the study area is highly polluted through Au mining activities, putting the environment and population health at risk, and that there is an urgent need for intervention by the environmental control agencies for remediation.

Chemical fractionation and bioaccessibility of potentially toxic elements in area of artisanal gold mining in the Amazon.

Artisanal mining may have modified the mobility, bioavailability and bioaccessibility of potentially toxic elements (PTEs) in the Serra Pelada gold mine, eastern Amazon, Brazil, which has not yet been studied. The objectives were to perform chemical fractionation of barium (Ba), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn), and to determine the bioaccessibility of these elements in soils and mining wastes collected in agriculture, forest, mining, and urban areas from the influence zone of the Serra Pelada gold mine. Pseudo total concentrations were obtained by acid digestion, chemical fractionation was performed using the Bureau Community of Reference (BCR) sequential extraction, oral bioaccessibility was obtained by the Simple Bioaccessibility Extraction Test (SBET) and lung bioaccessibility was obtained through Gamble's solution. The pseudo total concentrations indicated contamination by Ba, Cu and Ni. The sequential extraction revealed the predominance of all elements in the residual fraction. However, Ba is in high concentrations in the greater mobility forms, ranging from 166.36 to 1379.58 mg kg-1. Regardless of the area, Cr and Cu are more oral bioaccessible in the intestinal phase, and Zn in the gastric phase. Ba, Cr and Zn are not lung bioaccessible, while Cu, Ni and Pb are bioaccessible via inhalation. The PTEs studied deserve attention not only due to the high pseudo total concentrations found (which indicate potential risk), but also the concentrations in high mobility forms and bioaccessible fractions, especially in the areas of greatest anthropogenic occupation.

Estruturas secretoras da lâmina foliar de amapá amargo (Parahancornia fasciculata, Apocynaceae): histoquímica e doseamento de flavonoides / Secretory structures from the leaf blade of bitter amapá (Parahancornia fasciculata, Apocynaceae): histochemistry and assay of flavonoids

Bitter amapa (Parahancornia fasciculata (Poir.) Benoist) produces a latex, which is presumed to have medicinal properties, as it is used in the treatment of malaria, lung problems, gastritis, and as healing agent. This study aimed to analyze structural and histochemically the sites of production and/or accumulation of biologically active compounds, as well as to determine the kind of flavonoids present in the leaf blade of bitter amapa. For structural and histochemical analysis we used standard protocols in plant anatomy. Whereas to assay flavonoids we used absorption spectrometry in the ultraviolet-visible region. The secretory system of bitter amapa leaves is constituted of both secretory idioblasts and branched laticifers. Histochemical tests revealed different types of chemical substances in the cell protoplast of idioblasts and laticifers. Pharmacological properties of bitter amapa latex can be attributed to two chemical compounds (flavonoids and alkaloids) found in this study, both of them are present in idioblasts and laticifers.

Amapá amargo (Parahancornia fasciculata (Poir.) Benoist) produz um látex, que se presume ter propriedades medicinais, pois é usado no tratamento da malária, problemas pulmonares, gastrite, e como um agente de cura. Este estudo teve como objetivo analisar estrutural e histoquimicamente os locais de produção e/ou acumúlo de compostos biologicamente ativos, bem como realizar o doseamento de flavonóides presentes no limbo do amapá amargo. Para a análise estrutural e histoquímica foram utilizados protocolos padrão em anatomia vegetal. Considerando que, para o doseamento de flavonóides utilizou-se a espectrometria de absorção na região ultravioleta-visível. O sistema secretor das folhas de amapá amargo é constituído de idioblastos secretores e laticíferos ramificados. Os testes histoquímicos revelaram diferentes tipos de substâncias químicas nos protoplastos celulares de idioblastos e laticíferos. Propriedades farmacológicas do látex de amapa amargo podem ser atribuídas à dois compostos químicos (flavonoides e alcaloides) encontrados neste estudo, ambos estão presentes em idioblastos e laticíferos.

Estudo fitoquímico biomonitorado pelos ensaios de toxicidade frente à Artemia salina e de atividade antiplasmódica do caule de aninga (Montrichardia linifera) / Phytochemical study bioassay-guided by tests of toxicity on Artemia salina and antiplasmodial activity from stem of aninga (Montrichardia linifera)

Montrichardia linifera é uma planta aquática de amplo uso na medicina tradicional amazônica. Entretanto, muito pouco se conhece sobre a sua composição química, e sua atividade biológica ainda não foi comprovada. Na busca de substância(s) biologicamente ativa(s), este trabalho realizou um estudo fitoquímico biomonitorado no qual foram testados os extratos hexânico e etanólico obtidos do caule desta espécie, dos quais apenas o extrato etanólico foi selecionado para o fracionamento cromatográfico por ter apresentado toxicidade contra a Artemia salina e atividade contra o Plasmodium falciparum, parasita causador da malária. As atividades biológicas concentraram-se na fração diclorometânica que apresentou alta toxicidade contra A. salina (DL50<31µg mL-1) e alta atividade antiplasmódica (IC50<10 µg mL-1), mostrando promissora atividade antimalárica. Desta fração, o composto aromático p-hidroxibenzaldeído foi isolado pela primeira vez nesta planta.

Montrichardia linifera is an aquatic plant widely use in Amazon folkmedicine. However, very little is known about the chemical composition and biological activity. In search of biologically active (s) substance (s) phytochemical bioassay-guided study was conducted evaluating hexane extract and ethanol extract obtained from stems of this species. Since only the ethanol extract presented toxicity against Artemia salina and activity against Plasmodium falciparum, this extract was selected for chromatographic fractionation. The biological activities were concentred in dichloromethane fraction which showed high toxicity against A. saline (LD50< µg mL-1) and high antiplasmodial activity (IC50 <10 µg mL-1), showing promising antimalarial activity. Of this fraction, the aromatic compound p-hydroxybenzaldehyde was isolated for the first time in this plant.

Composição química e valor nutricional para grandes herbívoros das folhas e frutos de aninga (Montrichardia linifera, Araceae) / Chemical composition and nutritional value of leaves and fruits of aninga (Montrichardia linifera, Araceae) for large herbivores

Montrichardia linifera (Araceae), conhecida popularmente como 'aninga', faz parte dos ecossistemas de várzea da Amazônia e da dieta natural de animais como peixe-boi, tartarugas, peixes, búfalo e gado. Com o objetivo de contribuir para o conhecimento químico e valor nutricional da mesma, folhas e frutos de M. linifera foram coletados às margens dos rios Guamá e Maratauíra, no Estado do Pará, Brasil. Em folhas e frutos foram realizadas análises de umidade, resíduo mineral fixo (cinzas), lipídios, proteínas, fibra bruta, concentração de carboidratos e valor calórico. A composição mineral (Ca, Mg, Cu, Fe, Zn e Mn) foi obtida por espectrometria de absorção atômica de chama. Observou-se que tanto as folhas quanto os frutos da aninga, apesar de calóricos (289,75 kcal e 355,12 kcal, respectivamente), possuem baixo valor protéico (0,44% e 0,24 %, respectivamente). As concentrações de manganês obtidas (folha = 3279,46 mg kg-1e fruto = 18151,53 mg kg-1) foram consideradas tóxicas, extrapolando o limite máximo tolerável para ruminantes (1000 mg kg-1). A M. linifera, tem capacidade de absorver e bioacumular grandes quantidades de Ca, Mg e Mn presentes no solo, o que torna inadequada a sua utilização exclusiva na alimentação de quelônios, bovinos e bubalinos, havendo necessidade de mais estudos para sua aplicação como parte da ração.

The aninga (Montrichardia linifera, Araceae) is often found in the floodplain ecosystems of the Amazon and is the natural diet of animals such as manatees, turtles, fish, buffalo and cattle. Aiming to contribute to the chemical knowledge and nutritional value of this plant, leaves and fruits of M. linifera were collected on the banks of the Guama and Maratauira rivers, Para State, Brazil. We determined the moisture content, ash mineral composition, lipids, protein, fiber, carbohydrate and caloric value of the fruits and leaves. The mineral composition (Ca, Mg, Cu, Fe, Zn and Mn) was obtained by flame atomic absorption spectrometry. The leaves and the fruits of M. linifera had caloric values of 289.75 kcal and 355.12 kcal, respectively; and a low protein concentration, 0.44% for leaves and 0.24% for fruits. Manganese concentrations were 3279.46 mg kg-1 for leaves and 18151.53 mg kg-1 for fruits. These Mn concentrations are considered toxic, as they exceed the maximum tolerable for the ruminants (1000 mg kg-1). The M. linifera has the capacity to absorb and bioaccumulate large amounts of Ca, Mg and Mn in the soil, which makes it inappropriate for exclusive use as food for turtles, cattle and buffaloes, requiring more studies for its application as part of the diet.