This study evaluated the chemical composition, antioxidant and anticholinesterase activities, and the toxicity of hydroethanolic extracts of the Parkia platycephala Benth. Hot extraction with 70% hydroethanolic solution was used to obtain crude extracts of the leaf (LE), bark (BE), flower (FE), and seed (SE). Separation and identification of the compounds were performed by liquid chromatography with diode array detection and gas chromatography coupled with mass spectrometry. Antioxidant and anticholinesterase activities were performed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and Ellman methods, respectively, and the preliminary toxicity by the method with Artemia salina. Chromatography analysis indicated naringin, kaempferol, stigmasterol, and β-sitosterol in all extracts. Gallic acid is prominent in the LE and FE, while ferulic acid is abundant in the BE and lupeol and lupeol acetate are prominent in the SE. The BE antioxidant activity (lethal concentration of 50% (IC50) = 14.72 ± 0.13 µg mL-1) is equivalent to the standard rutin (IC50 = 15.85 ± 0.08 µg mL-1). The SE had the best acetylcholinesterase inhibition potential (IC50 = 5.73 ± 0.68 µg mL-1). Aside from the SE, which is not toxic, the other extracts had low (LE, FE) and moderate (BE) toxicity. The extracts of P. platycephala have potential antioxidant and therapeutic uses, especially against Alzheimer’s disease.

Ouratea fieldingiana is a native medicinal plant from Northeastern Brazil and many biological properties are due to the phenolic constituents. The objective of this work was performing the characterization of O. fieldingiana leaf constituents to correlate with antioxidant and anticholinesterase activities by in vitro and in silico studies and thus contribute to find new agents against Alzheimer’s disease. The high-performance liquid chromatography revealed the presence of the flavonoids rutin, isoquercitrin, kaempferol-3-O-rutinoside, quercetin, apigenin and amentoflavone. The antioxidant activities by the (2,2-diphenyl-1-picrylhydrazyl) (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methodologies, showed good results with half maximal inhibitory concentration (IC50) values ranging from 5.63 to 11.47 µg mL-1 and 2.72 to 23.71 µg mL-1, respectively. Acetylcholinesterase inhibition assay pointed out the flavone apigenin with best activity. Computational studies evaluated the interaction of flavonoids with the enzyme acetylcholinesterase co-crystallized with the galantamine, used as standard. All flavonoids exhibited binding energy greater than that of galantamine, but only apigenin showed strong interaction with the active site of the enzyme and other bind probably to different allosteric centers. Then, O. fieldingiana extract and flavonoids with good anti-radical activity and presenting a broad-spectrum action against acetylcholinesterase (AChE) enzyme ought to be tested in clinical studies to discover new neuro-therapeutic candidates.

The genus Cryptostegia comprises two species, C. madagascariensis (Bojer) and C. grandiflora (Roxb. Ex R. Br) that belong to the Apocynaceae family and are widely distributed in the tropics, as in Australia, New Zealand, India and Brazil, where they cause great socioeconomic and environmental damage, as they are invaders causing damage, mainly in the cultivation of carnaúba, a native plant of great importance in the wax and derivatives industry in Northeast Brazil. Both are perennial shrubs, native to the island of Madagascar, have abundant latex and are known as rubber vine. The plants have the potential for pharmacological, biological and industrial applications. This is due to a rich source of chemical compounds (proteins, phenols, flavonoids, steroids, triterpenoids, cardiac glycosides, etc.) resulting from primary and secondary metabolism. The plants of the Cryptostegia genus showed many activities against bacteria, fungi, insects, Ae. aegypti larvae, Shistosoma sp., as well as for human health as analgesic, anti-inflammatory, antioxidant and antitumoral, and for industrial purposes acting as fibrinogenolytic, hydrolytic, anticorrosive, coagulant and depilatory for leather. Nevertheless, the toxicity is a limitation for the plant use then in order to stand out the economic potential a detailed research on toxicity and management of growing conditions is necessary.

Carvacrol (CV) and carvacryl acetate (CVA) are bioactive compounds that have anthelmintic action and the nanoencapsulation may be an alternative to potentialize their efficacy. The aim of this work was to nanoencapsulate CV and CVA using chitosan/gums and evaluate cytotoxicity and the anthelmintic activity. A 24 factorial experimental design was performed to determine the influence of gum type (arabic or chichá), amount of surfactant and the number of layers in the nanoencapsulation degree. CVA and CV presented encapsulation efficiency (EE) optimum values of 90 and 20% (experiments 8 and 9), respectively. The monolayer and bilayer formulations presented maximum size of 479 and 811 nm, respectively. Nanoencapsulated CVA (nCVA) with bilayer coating and higher surfactant levels showed good thermal stability and no toxicity. In vitro kinetics for nCVA with chitosan/chichá gum showed slower release profiles than nCVA with chitosan/gum arabic, with 50% release after 30 and 20 h, respectively. CVA and nCVA at a concentration of 150 µg mL−1 reduced the motility of H. contortus adult nematodes by 100 and 91.7%, respectively. In summary, nCVA chitosan/chichá gum showed high encapsulation efficiency, favorable release rate and anthelmintic activity against H. contortus.

Chemotherapy treatment of leishmaniasis is based on the use of pentavalent antimonials, but these drugs present low efficacy and high toxicity. In the search for new antileishmanial agents, essential oils (EOs) from four Croton species (C. argyrophylloides, C. jacobinensis, C. nepetifolius and C. sincorensis) were evaluated against Leishmania infantum chagasi, L. amazonensis and L. braziliensis. EOs were analyzed by gas chromatography combined with mass spectrometry. Spathulenol, β-caryophyllene, β-caryophyllene oxide, 1,8-cineole and methyl eugenol were the major constituents. The evaluation of antioxidant activity by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) method showed that all EOs have moderate antioxidant activity. All oils were similarly active against L. i. chagasi, and C. nepetifolius EO showed the best result against L. amazonensis, with median inhibitory concentrations (IC50) of 9.87 μg mL-1, similar to amphotericin B (IC50 = 7.38 μg mL-1). The oils presented low cytotoxicity in macrophages. The in silico analysis revealed that spathulenol and 1,8-cineole were active against the enzyme Leishmania infantum trypanothione reductase (LiTR), showing excellent interaction energies, making them promising agents for leishmaniasis control.

RESUMO Este trabalho descreve a composição química e a atividade anti-Candida spp. de óleos essenciais de folhas de diversos cultivares de Mangifera indica. Os óleos essenciais foram obtidos por meio de hidrodestilação e analisados por cromatografia de gás acoplada à espectrometria de massa. A atividade anti-Candida spp. foi avaliada contra cepas isoladas de cães pelo método de difusão em ágar e a concentração inibitória mínima (CIM) pelo método de microdiluição em caldo. O cultivar Tommy Atkins apresentou β-selineno (29.49%), óxido de cariofileno (12.40%) e humuleno II epoxido (8.66%) como seus constituintes principais, enquanto que os principais componentes das variedades Rosa, Moscatel e Jasmim foram óxido de cariofileno (23,62, 48,42 e 30,77%, respectivamente) e humuleno II epoxido (11,56, 23,45 e 16,27%, respectivamente). As médias de zona de inibição foram 11 ± 0,71, 13,5 ± 3,54, 10,5 ± 0,71 e 13,5 ± 0,71mm respectivamente para os cultivares Tommy Atkins, Rosa, Moscatel e Jasmim. Para a variedade Tommy Atkins, a CIM variou de 0,62 a 1,25 mg/mL; para Rosa, 0.31 a 1.25 mg/mL; para Jasmim os valores variaram de 0,31 a 0,62 mg/mL; ao passo que para a variedade Moscatel o valor de CIM foi 1,25 mg/mL para todas as cepas de Candida spp. Os óleos essenciais das quatro variedades de M. indica foram ativos in vitro contra Candida spp., demonstrando boa atividade antifúngica, podendo ser uma fonte útil de compostos antifúngicos para uso na medicina veterinária.

SUMMARY This work reports the chemical study, and anti-Candida spp. activity of leaf essential oil from Mangifera indica cultivars. The essential oils were obtained by hydro-distillation and analyzed by gas chromatography/mass spectroscopy. The anti-Candida spp. activity was evaluated against strains isolated from dogs by the agar-well diffusion method and the minimum inhibitory concentration (MIC) by the broth microdilution method. Tommy Atkins cultivar presented β–selinene (29.49%), caryophyllene oxide (12.40%) and humulene II epoxide (8.66%) as main constituents, while the main constituents of Rosa, Moscatel and Jasmim varieties were caryophyllene oxide (23.62, 48.42 and 30.77%, respectively) and humulene epoxide II (11.56, 23.45, and16.27%, respectively). The means of inhibition zones were 11 ± 0.71, 13.5 ± 3.54, 10.5 ± 0.71 and 13.5 ± 0.71mm to Tommy Atkins, Rosa, Moscatel and Jasmim varieties, respectively. For Tommy Atkins, the MIC ranged from 0.62 to 1.25 mg/mL; for Rosa, ranged from 0.31 to 1.25 mg/mL; for Jasmim ranged from 0.31 to 0.62 mg/mL; while for the Moscatel variety the MIC value was 1.25 mg/mL for all Candida strains. Essential oils of four M. indica cultivars were active in vitro against Candida spp., demonstrating good antifungal activity and can be a useful source of antifungal compounds for veterinary medicine.

AbstractIn this study, the spray drying technique was used to prepare L-ascorbic acid (AA) microparticles encapsulated with galactomannan-an extract from the seeds of the Delonix regia species. The physico-chemical characteristics, antioxidant activity, and encapsulation efficiency of the AA microparticles were evaluated and characterized using thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The free-radical scavenging activity of the AA microparticles was determined at different environmental conditions using DPPH (1,1-diphenyl-2-picryl-hydrazyl). X-ray diffraction measurements demonstrated a loss of crystallinity in AA after the encapsulation process, and a DSC scan also showed the loss of the compound's melting peak. Thermogravimetric analysis showed small differences in the thermal stability of galactomannan before and after the incorporation of AA. The mean diameters of the obtained spherical microspheres were in the range of 1.39 ± 0.77 µm. The encapsulation efficiency of AA microparticles in different environmental conditions varied from 95.40 to 97.92, and the antioxidant activity showed values ranging from 0.487 to 0.550 mg mL-1.

Malassezia pachydermatisis associated with dermatomycoses and otomycosis in dogs and cats. This study compared the susceptibility of M. pachydermatis isolates from sick (G1) and healthy (G2) animals to azole and polyene antifungals using the M27-A3 protocol. Isolates from G1 animals were less sensitive to amphotericin B, nystatin, fluconazole, clotrimazole and miconazole.

Nos últimos anos, o Ministério da Saúde do Brasil e a Organização Mundial da Saúde tem apoiado a investigação de novas tecnologias que possam contribuir para a vigilância, novos tratamentos e controle da leishmaniose visceral no país. Assim, o objetivo deste trabalho foi isolar compostos de plantas do bioma Caatinga, e investigar a toxicidade destes compostos contra as formas promastigotas e amastigotas de Leishmania infantum chagasi, principal parasita responsável pela leishmaniose visceral na América do Sul, e avaliar a sua capacidade para inibir a enzima acetil-colinesterase (AChE). Após a exposição aos compostos em estudo, foram realizados testes utilizando a forma promastigota que expressa luciferase e ELISA in situ para medir a viabilidade das formas promastigotas e amastigota, respectivamente. O ensaio colorimétrico MTT foi realizado para determinar a toxicidade destas substâncias utilizando células monocíticas murina RAW 264.7. Todos os compostos foram testados in vitro para as sua propriedade anti-colinesterásica. Um cumarina, escoparona, foi isolada a partir de hastes de Platymiscium floribundum, e os flavonóides, rutina e quercetina, foram isolados a partir de grãos de Dimorphandra gardneriana. Estes compostos foram purificados, utilizando cromatografia em coluna gel eluída com solventes orgânicos em misturas de polaridade crescente, e identificados por análise espectral. Nos ensaios leishmanicidas, os compostos fenólicos mostraram eficácia contra as formas extracelulares promastigotas, com EC50 para escoporona de 21.4µg/mL e para quercetina e rutina 26 e 30.3µg/mL, respectivamente. Os flavonóides apresentaram resultados comparáveis à droga controle, a anfotericina B, contra as formas amastigotas com EC50 para quercetina e rutina de 10.6 e 43.3µg/mL, respectivamente. Os compostos inibiram a enzima AChE com halos de inibição variando de 0,8 a 0,6cm, indicando um possível mecanismo de ação para a atividade leishmanicida.

In recent years, the Brazilian Health Ministry and the World Health Organization have supported research into new technologies that may contribute to the surveillance, new treatments, and control of visceral leishmaniasis within the country. In light of this, the aim of this study was to isolate compounds from plants of the Caatinga biome, and to investigate their toxicity against promastigote and amastigote forms of Leishmania infantum chagasi, the main responsible parasite for South American visceral leishmaniasis, and evaluate their ability to inhibit acetylcholinesterase enzyme (AChE). A screen assay using luciferase-expressing promastigote form and an in situ ELISA assay were used to measure the viability of promastigote and amastigote forms, respectively, after exposure to these substances. The MTT colorimetric assay was performed to determine the toxicity of these compounds in murine monocytic RAW 264.7 cell line. All compounds were tested in vitro for their anti-cholinesterase properties. A coumarin, scoparone, was isolated from Platymiscium floribundum stems, and the flavonoids rutin and quercetin were isolated from Dimorphandra gardneriana beans. These compounds were purified using silica gel column chromatography, eluted with organic solvents in mixtures of increasing polarity, and identified by spectral analysis. In the leishmanicidal assays, the compounds showed dose-dependent efficacy against the extracellular promastigote forms, with an EC50 for scoporone of 21.4µg/mL, quercetin and rutin 26 and 30.3µg/mL, respectively. The flavonoids presented comparable results to the positive control drug, amphotericin B, against the amastigote forms with EC50 for quercetin and rutin of 10.6 and 43.3µg/mL, respectively. All compounds inhibited AChE with inhibition zones varying from 0.8 to 0.6, indicating a possible mechanism of action for leishmacicidal activity.

We investigated the in vitro effect of the essential oil of Croton nepetifolius Baill., Euphorbiaceae (EOCN), on spontaneous or induced contractions of circular and longitudinal muscles from the ovine cervix during the luteal phase of the estrous cycle. The relaxant effect of EOCN was expressed as a percentage of the contraction recorded before the addition of the oil and calculated relative to the preparations exposed only to the vehicle. The IC50 (concentration of oil required to produce a 50% maximal reduction in muscle contraction) for relaxation of spontaneous contractions in circular and longitudinal muscles was significantly lower than the IC50 for blockade of K+-induced contraction (27.19 µg mL-1 versus 262.72 µg mL-1 and 40.92 µg mL-1 versus 222.47 µg mL-1, respectively). Interestingly, there was a high degree of selectivity in the action of EOCN on cervix layers concerning the inhibition of acetylcholine-induced contraction in circular (IC50 277.10 µg mL-1) and longitudinal (IC50 52.56 µg mL-1) muscles. In conclusion, EOCN is able to relax ovine cervix during the luteal phase. This work opens the perspective of applying EOCN in ovine embryo transfer.

Folhas de Byrsonima sericea são amplamente utilizadas na medicina popular no Brasil no tratamento de distúrbios gástricos. Este estudo investigou os constituintes químicos do extrato etanólico das folhas de B. sericea (BSLE) e sua atividade gastroprotetora com seus possíveis mecanismos de ação utilizando o modelo de lesão gástrica induzida por etanol em camundongos. A análise fitoquímica foi realizada para identificar os componentes ativos presentes no extrato e análise por HPLC foi realizada para a identificação de flavonóides. A administração de BSLE (v.o.) nas doses de 125, 250, 500 mg/kg, v.o. atenuou significativamente as lesões gástricas induzidas por etanol em 53,2, 84,9 e 87,6% respectivamente. BSLE (250 mg/kg) preveniu a depleção do muco gástrico, de grupamentos sulfidrílicos não-protéicos (GSH), das atividades da SOD e da CAT assim como o aumento de malonaldeído promovido pelo etanol. Além disso, o efeito gastroprotetor do BSLE foi significantemente reduzido pelos pré-tratamentos com capsazepina (i.p.), L-NAME (i.p.) ou glibenclamida (i.p.), respectivamente bloqueadores/inibidores de receptores TRPV1, NO sintase e canais de K+ATP. A investigação fitoquímica revelou a presença de flavonoides como rutina, isoquercitrina, 3-O-rutinosideo-canferol e quercetina que são conhecidas por suas propriedades antioxidantes e gastropotetoras. O estudo demonstrou que BSLE proporciona ação gastroprotetora através de vários mecanismos que podem ser úteis no tratamento de patologias associadas a disfunções gástricas.

Byrsonima sericea leaves are extensively used in folk medicine in Brazil against gastric disorders. This study investigated the chemical constituents of B. sericea leaf ethanolic extract (BSLE) and its potential gastroprotective activity, with its possible mechanism of the action using ethanol to induce gastric mucosal damage in mice. The phytochemical analysis was carried out to identify the active constituents present in the extract, and the HPLC analysis was performed for the identification of flavonoids. BSLE at oral doses of 125, 250 and 500 mg/kg markedly attenuated the ethanol-evoked gastric lesions by 53.2, 84.9 and 87.6 %, respectively. The BSLE (250 mg/kg) prevented the depletion of gastric mucus and gastric mucosal nonproteic-sulfhydryl groups, SOD and CAT, as well as the increase in the MDA content promoted by absolute ethanol. Moreover, the effect of BSLE against ethanol damage was found to be significantly reduced in mice pretreated with Capsazepine (i.p.), L-NAME (i.p.) or glibenclamide (i.p.), the respective blockers/inhibitors of TRPV1, NO synthase and K+ATP channel. The phytochemical investigation on BSLE revealed the presence of flavonoids rutin, isoquercitrin, kaempferol 3-O-rutinoside and quercetin, which are compounds well known for their antioxidant and gastroprotective properties. These results suggest that BSLE affords gastroprotection through multiple mechanisms, which may be helpful in the treatment of pathologies associated with gastric dysfunctions.

Plantas taniníferas representam uma promissora alternativa de controle dos nematóides gastrintestinais de pequenos ruminantes. Esse experimento avaliou in vitro os efeitos dos extratos das folhas e caules de Anadenanthera colubrina, Leucaena leucocephala e Mimosa tenuiflora sobre o desembainhamento larvar de Haemonchus contortus e verificou o papel dos taninos nesse processo. Larvas de terceiro estádio de H. contortus foram incubadas com 300 µg.mL-1 de extrato por 3 horas e expostas a uma solução de hipoclorito de sódio. O ensaio foi acompanhado por controles: solução salina tamponada com fosfato (PBS) e polivinilpolipirrolidona (PVPP). O desembainhamento larvar foi avaliado durante 60 minutos e os resultados submetidos ao teste Kruskal-Wallis (p < 0,05). Os seis extratos bloquearam o desembainhamento larvar. Após adição de PVPP, um inibidor de taninos, o percentual de desembainhamento foi similar ao PBS (p > 0,05), exceto nos extratos das folhas de L. leucocephala e M. tenuiflora. Entretanto, a pré-incubação desses dois extratos com PVPP alterou significativamente o desembainhamento quando comparado com extratos não-tratados (p < 0,05). Esses resultados sugerem que A. colubrina, L. leucocephala e M. tenuiflora podem ser úteis no controle de nematóides gastrintestinais e que os taninos são provavelmente os principais compostos envolvidos nos efeitos. Contudo, estudos toxicológicos e in vivo são necessários.

Tanniferous plants represent a promising alternative for controlling gastrointestinal nematodes of small ruminants. This experiment evaluated the effects of extracts from the leaf and stem of Anadenanthera colubrina, Leucaena leucocephala and Mimosa tenuiflora on larval exsheathment of Haemonchus contortus in vitro and verified the role of tannins in this process. Third-stage larvae of H. contortus were incubated with extracts for 3 hours and were exposed to sodium hypochlorite solution. The extracts were tested at 300 µg.mL-1 and accompanied by controls: phosphate buffer solution (PBS) and polyvinyl polypyrrolidone (PVPP). The larval exsheathment was evaluated for 60 minutes, and the results were subjected to the Kruskal-Wallis test (p < 0.05). The six extracts blocked larval exsheathment. After PVPP addition, a tannin inhibitor, the exsheathment percentage was similar to the PBS (p > 0.05), except for L. leucocephala and M. tenuiflora leaf extracts. However, pre-incubation with PVPP of these two extracts significantly changed larval exsheathment when compared to the non-treated extracts (p < 0.05). These results suggest that A. colubrina, L. leucocephala and M. tenuiflora could be useful in gastrointestinal nematode control and that tannins are probably the main compounds involved in the observed effects. However, in vivo and toxicological studies should be conducted.

Este trabalho objetivou avaliar a toxicidade dos extratos aquosos de sementes de 15 espécies de leguminosas contra larvas de Aedes aegypti. Foi realizada uma caracterização química e bioquímica parcial dos extratos aquosos e a avaliação da toxicidade aguda em camundongos. Os extratos de Amburana cearensis, Anadenanthera macrocarpa, Dioclea megacarpa, Enterolobium contortisiliquum e Piptadenia moniliformis causaram 100% de mortalidade depois de 1 a 3 h de exposição e mostraram valores de CL50 e CL90 entre 0,43 = 0,01 e 9,06 ± 0,12 e entre 0,71 = 0,02 e 13,03 = 0,15 mg/mL, respectivamente. Dentre os constituintes do metabolismo secundário, os extratos das sementes apresentaram taninos, fenóis, flavonas, flavonóis, xantonas, saponinas e alcalóides. Os extratos apresentaram alto teor de proteínas solúveis (0,98 to 7,71 mg/mL), lectina (32 to 256 UH/mL) e inibidor de tripsina (3,64 ± 0,43 to 26,19 = 0,05 gIT/kg de farinha). O perfil eletroforéticomostrou uma grande diversidade de proteínas, muitas dasquais já descritas como inseticidas. Os extratos mostraram baixa toxicidade ao camundongo (DL50 > 0,15 = 0,01 g/kg peso corporal), porém apesar desses resultados promissores, estudos posteriores são necessários para compreender a toxicidade desses extratos e de seus constituintes do metabolismo primário e secundário sobre Ae. aegypti.

This study assessed the toxicity of seed water extracts of 15 leguminous species upon Aedes aegypti larvae. A partial chemical and biochemical characterization of water extracts, as well as the assessment of their acute toxicity in mice, were performed. The extracts of Amburana cearensis, Anadenanthera macrocarpa, Dioclea megacarpa, Enterolobium contortisiliquum and Piptadenia moniliformis caused 100% of mortalit y after 1 to 3 h of exposure. They showed LC50 and LC90 values ranging from 0.43 ± 0.01 to 9.06 ± 0.12 mg/mL and from 0.71 ± 0.02 to 13.03 ± 0.15 mg/mL, respectively. Among the secondary metabolite constituents, the seed water extracts showed tannins, phenols, flavones, favonols, xanthones, saponins and alkaloids. The extracts also showed high soluble proteins content (0.98 to 7.71 mg/mL), lectin (32 to 256 HU/mL) and trypsin inhibitory activity (3.64 = 0.43 to 26.19 = 0.05 gIT/kg of flour) The electrophoretic profiles showed a great diversity of protein bands, many of which already described as insecticide proteins. The extracts showed low toxicity to mice (LD50 > 0.15 = 0.01 g/kg body weight), but despite these promising results, further studies are necessary to understand the toxicity of these extracts and their constituentsfrom primary and secondary metabolism upon Ae. aegypti.

Esferas de alginato (ALG) reticuladas com cálcio e revestidas com goma do cajueiro (GC) foram preparadas e dopadas com óleo essencial de Croton zehntneri Pax et Hoffm (Cz), visando a seu emprego como larvicida para combate ao vetor da dengue. As esferas foram caracterizadas estruturalmente por espectroscopia de infravermelho, análise térmica, microscopia eletrônica de varredura e em relação aos seus parâmetros de transporte líquido, dopagem, embebição (Q) e cinética de liberação in vitro e in vivo. Os resultados revelaram que as esferas possuem morfologia com uma alta regularidade esférica, com superfície porosa. A matriz ALG:Cz =1:1 apresentou maior dopagem e eficiência de encapsulamento e valores de Q entre 10 e 12. O perfil de liberação do óleo encapsulado apresentou-se mais prolongado nas esferas contendo goma do cajueiro, ALG-GC:Cz =1:1. A taxa de mortalidade de larvas de Stegomyia aegypti para teores de 1,81 a 4,25 mg de óleo nas esferas resultou em valores na faixa de 72 a 100%, após 24 h. A matriz polimérica mostrou-se efetiva para proteção do principio ativo até cerca de 70 dias, com perdas da ordem de 35%. A análise térmica revelou que a incorporação de Cz e GC resulta em uma matriz polimérica termicamente mais estável.

Alginate beads (ALG) crosslinked with calcium and coated with cashew gum (GC) were prepared and loaded with an essential oil from Croton zehntneri Pax et Hoffm (Cz). The beads were characterized by FTIR, thermal properties, with respect to their size, shape, larvicide loading, swelling, and in vitro and in vivo release kinetics. Results showed that beads with ALG:Cz =1:1 relative ratio showed higher loading and encapsulation efficiency, although presenting a faster release kinetics. On the other hand, ALG beads coated with GC showed Q values from 10 to 12, representing a significant increase in the hydrophilic character of the matrix. Infrared spectroscopy and thermal analysis confirmed the presence of essential oil encapsulated in beads. Morphologic investigation by SEM revealed a highly spherical and porous surface. The in vitro profile showed that the Cz oil encapsulated had a prolonged release in ALG-GC beads, probably due to the crosslinking. In vivo tests showed that the mortality degree was related to the mass of the beads, where beads having oil content from 1.81 to 4.25 mg caused larvae mortalities from 72 to 100% after 24 h. The control release system was found to be effective up to 70 days. These results showed that ALG-GC beads loaded with Cz are promising candidate for the control of Stegomyia aegypti larvae.

Lutzomyia longipalpis é o principal vetor da Leishmaniose visceral no Brasil. O objetivo deste trabalho foi avaliar o efeito do óleo de sementes de nim (Azadirachta indica) sobre ovos, larvas e adultos do vetor. Os insetos foram capturados no campo e mantidos no laboratório a ± 27 °C e 80% de umidade relativa. Cinco tratamentos com diferentes concentrações foram realizados, usando-se dois controles negativos, um com água destilada e outro com Tween 80 (3%) e um controle positivo com cipermetrina. Os ovos foram borrifados com o óleo em diferentes concentrações e avaliou-se o número de larvas eclodidas por 10 dias consecutivos. A mortalidade das larvas foi observada até a pupação, e a mortalidade dos adultos foi observada após 24, 48, e 72 horas. A análise estatística foi feita pelo teste de Tukey a 5% de probabilidade. No teste com ovos, a maior concentração obteve 65,16 ± 3,24% de eficácia. O teste com larvas apresentou 67,75 ± 2,21% de eficácia na concentração de 100 mg.mL-1. Com adultos, a eficácia na concentração de 100 mg.mL-1 foi de 96,64 ± 4,11%, após 24 horas. A análise fitoquímica revelou a presença de triterpenos. Esses resultados demonstram o potencial uso desse óleo no controle deste vetor.

Lutzomyia longipalpis is the main vector of visceral leishmaniasis in Brazil. The objective was to evaluate the effect of oil from (Azadirachta indica) neem seeds on eggs, larvae and adults of the vector. The insects were captured in the field and kept in the laboratory at ± 27 °C and 80% relative humidity. Five treatments with different concentrations were performed using two negative controls (distilled water and Tween 80) and a positive control. The eggs were sprayed with the oil at different concentrations and the number of hatched larvae evaluated for 10 days. Mortality of larvae was observed to pupation and adult mortality was observed after 24, 48, and 72 hours. Statistical analysis was performed by Tukey test at 5% probability. The highest oil concentration of eggs obtained 65.16 ± 3.24% efficacy for reducing egg hatching. The test with larvae showed 67.75 ± 2.21% efficacy at a concentration of 100 mg.mL-1. In adults, the efficacy of the 100 mg.mL-1 concentration was 96.64 ± 4.11% after 24 hours. The phytochemical analysis revealed the presence of triterpenes. These results demonstrate the potential use of this oil in the control of this vector.