Direct red 83 textile dye degradation using photoperoxidation and photo-fenton: kinetic studies, toxicity and neural networks modeling

Textile dyes have been observed in aquatic matrices that receive effluents from different textile industries. These compounds have the peculiarity of being resistant to the physical, chemical and biological treatments commonly used in wastewater treatment plants. Thus, alternative treatments such as advanced oxidative processes (AOP) have been considered in order to promote the degradation of this type of pollutant, being the photoperoxidation and photo-Fenton processes the most used. Therefore, the present work evaluated the efficiency of these AOP in the degradation of direct red 83 dye. It was found a greater efficiency of the photoperoxidation process, especially in the degradation of functional groups observed at 289 nm. This AOP presented a pseudo first order reaction kinetics, with rapid decay in the first minutes. The MLP (5-21-2) neural network model was able to satisfactorily predict the degradation of the dye under study. Finally, it was found that the proposed process showed no adverse effects when studying the toxicity in bacteria

Esterase activity in homogenates of Helicoverpa armigera (Hubner) (Lepidoptera: noctuidae) exposed to different insecticides and the behavioral effect

The toxicity of some insecticides to Helicoverpa armigera was studied through sublethal effects, evaluating the enzymatic activity of esterase and the behavioral response. The commercial formulation of insecticides selected were chlorpyrifos, spinosad, indoxacarb, chlorantraniliprole, lambda-cyhalothrin and Bacillus thuringiensis, corresponding the most used by farmers to control of H. armigera. To determine the esterase activity, the larvae were fed with soybean leaf discs dipped in insecticide solution using the lethal concentration (LC50). For the behavioral response, filter paper were immersed in three concentrations of insecticides (LC50, LC95 and recommend dose.), then the behavior of the larvae observed in Videomex-One. The results for the enzymatic activity showed an increase in the activity of the esterase, with variation along the treatments and the time of exposure of the insects to the insecticides. With exception of spinosad, other insecticides showed an increase in EST-α activity, 6 and 24 hours after contact of caterpillars with insecticide.Different behavioral patterns of walking (walking distance, walking speed and resting time) were observed for H. armigera exposed to different insecticides. H. armigera exposed to chlorpyrifos, lambda-cyhalothrin and B. thuringiensis insecticides show greater esterase activity. Regarding walking behavior, the results confirms enzymatic activity, where H. armigera have behavioral alteration after exposure to insecticide

Avaliação cinética e ecotoxicológica da degradação do corante têxtil direct orange 26 por processos Fenton e foto-Fenton/solar

The presence of color in textile effluents has been studied because of the need for more effective treatments. Therefore, advanced oxidative processes (AOP) have been used in the degradation of dyes, as well as in the conversion of organic matter. This study evaluated the degradation of the direct orange 26 textile dye by Fenton and photo-Fenton processes (with natural solar radiation). A statistical analysis, based on factorial 23 indicated the best working conditions, being: [H2O2] = 100 mg·L-1 and pH 3-4, for both AOP in that the [Fe] =  1 e 5 mg·L-1, for photo-Fenton and Fenton, respectively. The results of the kinetic studies demonstrated a good fit to the nonlinear kinetic model proposed by Chan and Chu, with values of R2 > 0,996 (photo-fenton) and R2 > 0,939 (Fenton). The tests performed to evaluate the chemical oxygen demand indicated conversions of 62.05% (Fenton) and 66.41% (photo-Fenton). Finally, the ecotoxicity study indicated that the post-treatment samples were non-toxic to the bacteria Escherichia coli and Proteus mirabilis but showed growth inhibition for Lactuca sativa (Fenton and photo-Fenton) seeds and for Brassica juncea and Portulaca grandiflora (Fenton).A presença de cor em efluentes têxteis tem sido alvo de estudo, devido a necessidade de tratamentos mais eficazes. Diante disso, processos oxidativos avançados (POA) têm sido utilizados na degradação de corantes, assim como na conversão da matéria orgânica. Este estudo avaliou a degradação do corante têxtil laranja direto 26 via processos Fenton e foto-Fenton (com radiação solar natural). Uma análise estatística, baseada em planejamentos fatoriais 23 indicaram as melhores condições de trabalho, sendo elas: [H2O2] = 100 mg·L-1 e pH 3-4, para ambos os POA em quanto que a [Fe] =  1 e 5 mg·L-1, para o foto-Fenton e o Fenton, respectivamente. Os resultados dos estudos cinéticos demonstraram um bom ajuste ao modelo cinético não-linear proposto por Chan e Chu apresentando R2 > 0,996 (foto-Fenton) e R2 > 0,939 (Fenton). Os ensaios realizados para avaliação da demanda química de oxigênio indicaram conversões de 62,05% (Fenton) e 66,41% (foto-Fenton). Por fim, o estudo de ecotoxicidade indicou que as amostras pós-tratamento não são tóxicas para as bactérias Escherichia coli e Proteus mirabilis, mas apresentou inibição do crescimento para sementes de Lactuca sativa (Fenton e foto-Fenton) e para Brassica juncea e Portulaca grandiflora (Fenton)

Cytotoxicity and genotoxicity assessment of the extract and lectins from Moringa oleifera Lam. Seeds / Avaliação da citotoxicidade e genotoxicidade do extrato e lectinas das sementes de Moringa oleifera Lam

Moringa oleifera seeds are used globally as a treatment for water and contain the lectins cMoL and WSMoL, which display coagulant activity. In this study, we sought to determine the cytotoxicity and genotoxicity of the M. oleifera seed extract (SE), prepared with the same procedure that people use for treating water, as well as cMoL and WSMoL, in human peripheral blood mononuclear cells (PBMCs). Cell viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay, while genotoxicity was evaluated using the comet assay, with cell nucleoids categorized in classes ranging from 0 (without damage) to 4 (maximum damage). The PBMCs treated with SE, cMoL, and WSMoL displayed viability higher than 60% in treatments with concentrations up to 100 µg/mL. In addition, SE and cMoL displayed low genotoxicity owing to the detection of nucleoids in class 1. However, the number of nucleoids in all classes increased when 50 and 100 µg/mL of WSMoL was administered, reaching a damage frequency of 50.0%. Although M. oleifera SE, cMoL, and WSMoL were not cytotoxic to PBMCs after 24 h of exposure, dose-dependent genotoxic effects were observed, especially with WSMoL. These findings indicate that caution must be exercised when selecting a lectin/extract concentration for water treatment

The first serine protease inhibitor from Lasiodora sp. (Araneae: Theraphosidae) hemocytes

AbstractThis work reports, for the first time, the purification, characterization and antibacterial activity of an elastase inhibitor from Lasiodora sp. hemocytes (EILaH). The hemocyte extract inhibited chymotrypsin (22%), trypsin (44%), tissue plasminogen activator (52%), urokinase (58%) and human neutrophil elastase (99%). EILaH was purified by Trypsin-Sepharose column and RP-HPLC. SDS-PAGE of EILaH revealed a molecular mass of 8kDa and MALDI-TOF mass spectrometry revealed a single molecular mass of 8274Da. The amino terminal sequence determined was LPC(PF)PYQQELTC. The dissociation constant (Ki) for human neutrophil elastase was 0.32nM. Hemocyte extract exerted antibacterial effect on Bacillus subtilis and Enterococcus faecalis, while EILaH was only active against E. faecalis. Currently, Lasiodora sp. is undergoing a systematic review and this study contributes to molecular characterization of the genus. In addition, the results suggest that serine protease inhibitors expressed in Lasiodora sp. hemocytes may be involved in the defense against bacterial infection

Schinus terebinthifolius leaf extract causes midgut damage, interfering with survival and development of Aedes aegypti larvae

In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4), as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3–1.35%, w/v) for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae) and 1.03% (fed larvae). Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae), 61.7% of individuals emerged as adults. The extract (1.0%) promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates that caution should be used when employing this extract as a larvicidal agent

Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications

Lectins are proteins extensively used in biomedical applications with property to recognize carbohydrates through carbohydrate-binding sites, which identify glycans attached to cell surfaces, glycoconjugates, or free sugars, detecting abnormal cells and biomarkers related to diseases. These lectin abilities promoted interesting results in experimental treatments of immunological diseases, wounds, and cancer. Lectins obtained from virus, microorganisms, algae, animals, and plants were reported as modulators and tool markers in vivo and in vitro; these molecules also play a role in the induction of mitosis and immune responses, contributing for resolution of infections and inflammations. Lectins revealed healing effect through induction of reepithelialization and cicatrization of wounds. Some lectins have been efficient agents against virus, fungi, bacteria, and helminths at low concentrations. Lectin-mediated bioadhesion has been an interesting characteristic for development of drug delivery systems. Lectin histochemistry and lectin-based biosensors are useful to detect transformed tissues and biomarkers related to disease occurrence; antitumor lectins reported are promising for cancer therapy. Here, we address lectins from distinct sources with some biological effect and biotechnological potential in the diagnosis and therapeutic of diseases, highlighting many advances in this growing field

Antioxidant, antimicrobial and immunostimulant properties of saline extract from Caesalpinia pulcherrima (L.) Swartz (Fabaceae) leaves

281-289Caesalpinia pulcherrima (L.) Swartz is a species that originates in India and Central America and is widely distributed in the world. This plant presents important biological properties, due to the presence of some secondary medicinal metabolites, such as tannins, glycosides, flavonoids and diterpenes. In folk medicine, C. pulcherrima is used in different diseases as bronchitis, asthma, infections, wounds and eye irritations. The aim of this study was to perform a phytochemical screening and evaluate which biological properties the saline extract of leaves from C. pulcherrima have against microorganisms and animal cells. Results showed that 15 majority compounds could be found in saline extract distributed among phenol, coumarin and quercetin groups.Saline extract of leaves from C. pulcherrima also showed good results in antioxidant test and showed significant antifungal property against Candida strains. Moreover, the saline extract did not showed cytotoxicity against mice splenocytes and promoted proliferation in these cells. These results may be predictive for future studies using the saline extract from C. pulcherrima leaves as cell stimulant agent in a pharmaceutical phytotherapic formulation used in cicatricial and in vitro immunostimulant assays

Evaluation of the insecticidal potential of leaf extracts of Anadenanthera colubrina var. cebil (Griseb) Altschul against Tetranychus urticae Koch and Sitophilus zeamais Mots

The deterioration and degradation of crops by insects causes economic losses of several billion dollars and affects food security. Sitophilus zeamais and Tetranychus urticae are two economically important species of agricultural crops around the world. The high toxicity of synthetic insecticides and the development of insect resistance to currently used chemicals stimulate the investigation of plant-derived insecticides as new alternatives for pest control. The insecticidal properties of secondary metabolites have been recognized, and have been confirmed scientifically in the last decades. The extract in cyclohexane (Ch) and ethyl acetate (Ea) of the leaves of Anadenanthera colubrina var. cebil collected in the dry and rainy seasons were evaluated for the survival and nutritional physiology of S. zeamais (maize weevil) and for the acaricidal effect front T. urticae (two-spotted spider). All extracts induced mortality of S. zeamais; however, only cyclohexane dry season (Chd) and ethyl acetate in the rainy season (Ear) caused significant mortality (p <0.05), more than 50%, promoting physiological damage to insects in all concentrations tested. In the mortality tests with the spider mite, extracts Chd and Ear showed an LC50 of 52.75 and 156.42 mg.mL-1. Still, in the same test, it can be observed that oviposition was also susceptible to extracts. Therefore, the extracts of A. colubrina are a source of compounds capable of interfering with and impairing the metabolism of the two studied pests