RESUMO
Bacterial resistance has become a serious public health problem in recent years, thus encouraging the search for new antimicrobial agents. Here, we report an antimicrobial peptide (AMP), called PEPAD, which was designed based on an encrypted peptide from a Kunitz-type plant peptidase inhibitor. PEPAD was capable of rapidly inhibiting and eliminating numerous bacterial species at micromolar concentrations (from 4µM to 10 µM), with direct membrane activity. It was also observed that the peptide can act synergistically with ciprofloxacin and showed no toxicity in the G. mellonella in vivo assay. Circular dichroism assays revealed that the peptide's secondary structure adopts different scaffolds depending on the environment in which it is inserted. In lipids mimicking bacterial cell membranes, PEPAD adopts a more stable α-helical structure, which is consistent with its membrane-associated mechanism of action. When in contact with lipids mimicking mammalian cells, PEPAD adopts a disordered structure, losing its function and suggesting cellular selectivity. Therefore, these findings make PEPAD a promising candidate for future antimicrobial therapies with low toxicity to the host.
RESUMO
BACKGROUND: Compatibility studies of insecticides and natural enemies usually focus on short-term lethal effects, without considering the long-term sublethal effects (including progeny). Even less-explored are the effects of commercial insecticides formulated with more than one active product. Short- and long-term lethal and sublethal effects were studied for the first time on the progeny of commercial formulations of spirotetramat, imidacloprid and a commercial mixture of these active ingredients on pupae of Diaeretiella rapae (M'ntosh) (Hymenoptera: Braconidae), an endoparasitoid of aphids considered to be a potential biological control agent. Insecticides were exposed topically on aphid mummies in which the parasitoid was in the pupal stage. RESULTS: Imidacloprid reduced adult emergence by more than 30% and prolonged intra-host development time with respect to control from half the maximum recommended field dose (MFRD). Spirotetramat and commercial mixture only showed significant effects on these endpoints at doses above the MFRD. The tested formulations did not affect adult longevity, sex ratio, and percentage of parasitism in the exposed generation. At low concentrations the active ingredients in the commercial mixture behave synergistically, whereas at medium and high concentrations they behave antagonistically. Considering the 10% lethal dose (LD10), imidacloprid showed the highest hazard coefficient, whereas the commercial mixture was more hazardous when considering the LD50 and LD90. The commercial mixture and imidacloprid induced higher adult emergence and altered the sex ratio in the progeny. CONCLUSIONS: The following order of toxicity on D. rapae can be established: imidacloprid > commercial mixture > spirotetramat. Joint use of this species with imidacloprid and commercial mixture should be avoided in integrated pest management programs. © 2024 Society of Chemical Industry.
Assuntos
Compostos Aza , Inseticidas , Neonicotinoides , Nitrocompostos , Pupa , Compostos de Espiro , Vespas , Animais , Compostos de Espiro/toxicidade , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Vespas/efeitos dos fármacos , Vespas/fisiologia , Vespas/crescimento & desenvolvimento , Afídeos/efeitos dos fármacos , Afídeos/parasitologia , Feminino , Imidazóis/toxicidadeRESUMO
Endothelial cells express multiple receptors mediating estrogen responses; including the G protein-coupled estrogen receptor (GPER). Past studies on nitric oxide (NO) production elicited by estrogens raised the question whether 17-ß-estradiol (E2) and natural phytoestrogens activate equivalent mechanisms. We hypothesized that E2 and phytoestrogens elicit NO production via coupling to distinct intracellular pathways signalling. To this aim, perfusion of E2 and phytoestrogens to the precontracted rat mesentery bed examined vasorelaxation, while fluorescence microscopy on primary endothelial cells cultures quantified single cell NO production determined following 4-amino-5-methylamino-2',7'-difluoroescein diacetate (DAF) incubation. Daidzein (DAI) and genistein (GEN) induced rapid vasodilatation associated to NO production. Multiple estrogen receptor activity was inferred based on the reduction of DAF-NO signals; G-36 (GPER antagonist) reduced 75 % of all estrogen responses, while fulvestrant (selective nuclear receptor antagonist) reduced significantly more the phytoestrogens responses than E2. The joint application of both antagonists abolished the E2 response but not the phytoestrogen-induced DAF-NO signals. Wortmannin or LY-294002 (PI3K inhibitors), reduced by 90% the E2-evoked signal while altering significantly less the DAI-induced response. In contrast, H-89 (PKA inhibitor), elicited a 23% reduction of the E2-induced signal while blocking 80% of the DAI-induced response. Desmethylxestospongin-B (IP3 receptor antagonist), decreased to equal extent the E2 or the DAI-induced signal. Epidermal growth factor (EGF) induced NO production, cell treatment with AG-1478, an EGF receptor kinase inhibitor reduced 90% DAI-induced response while only 53% the E2-induced signals; highlighting GPER induced EGF receptor trans-modulation. Receptor functional selectivity may explain distinct signalling pathways mediated by E2 and phytoestrogens.
Assuntos
Proteínas Quinases Dependentes de AMP Cíclico , Receptores ErbB , Estradiol , Óxido Nítrico , Fosfatidilinositol 3-Quinases , Fitoestrógenos , Transdução de Sinais , Vasodilatação , Animais , Fitoestrógenos/farmacologia , Estradiol/farmacologia , Óxido Nítrico/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Receptores ErbB/metabolismo , Masculino , Isoflavonas/farmacologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Genisteína/farmacologia , Receptores de Estrogênio/metabolismo , Ratos WistarRESUMO
The aim of this study was to assess the efficacy of herbicides in association to control Rottboellia exaltata and Ipomoea quamoclit during pre-emergence while also to evaluate the potential impact on the sugarcane. The experimental design employed a randomized block with seven treatments and four replications. The treatments were: 1 - no herbicide application; 2 - indaziflam + sulfentrazone; 3 - indaziflam + diclosulam; 4 - indaziflam + tebuthiuron; 5 - flumioxazin + diclosulam, 6 - flumioxazin + pyroxasulfone and 7 - clomazone + sulfentrazone. The evaluated parameters were: percentage of weeds control, green coverage percentage (Canopeo® system), weed biomass (g m-2), itchgrass height, and sugarcane tiller. Several herbicide associations have been proven effective alternatives for managing itchgrass and cypressvine morningglory. The most successful treatments for itchgrass control were indaziflam + tebuthiuron (100%) and indaziflam + diclosulam (97%), whereas for cypressvine morningglory, the betters were indaziflam + sulfentrazone (97%), indaziflam + diclosulam (98%), indaziflam + tebuthiuron (97%), flumioxazin + diclosulam (94%), and clomazone + sulfentrazone (96%). All treatments reduced the weed biomass, with indaziflam + tebuthiuron being the safest option for protecting sugarcane.
Assuntos
Herbicidas , Saccharum , Controle de Plantas Daninhas , Herbicidas/farmacologia , Controle de Plantas Daninhas/métodos , Plantas Daninhas/efeitos dos fármacos , Ipomoea/efeitos dos fármacosRESUMO
Insecticides efficient against the target species while conserving natural enemies in the agroecosystem are required for IPM. With the imminent discontinuation of fipronil, a broad-spectrum insecticide, ethiprole, which belongs to the same group as phenylpyrazole (2B), and isocycloseram, a novel isoxazoline insecticide with distinct mode of action (30), provide options for controlling boll weevil. The susceptibility of the boll weevil, Anthonomus grandis grandis (Boh.), and two natural enemies [Eriopis connexa (Germar) and Bracon vulgaris Ashmead] to these insecticides were studied. Furthermore, the survival and biological traits of the lady beetle, E. connexa, exposed to fipronil, isocycloseram, and ethiprole were assessed. The LC50s values for fipronil, ethiprole, and isocycloseram for A. grandis grandis were 2.71, 0.32, and 0.025 mg a.i./L, respectively; 0.86, > 200, and 3.21 mg a.i./L for E. connexa; and 2.31, 592.94, and 0.18 mg a.i./L for B. vulgaris, respectively. The recommended rates of ethiprole did not cause mortality in adult lady beetles, although fipronil and isocycloseram were highly toxic. Lady beetle larvae and adults survived more than 80% when exposed to dried residues of ethiprole, but less than 10% when exposed to fipronil and isocycloseram. Lady beetle larvae development, reproduction, and predation rates of adults were similar between ethiprole and the control group. Although fipronil and ethiprole belong to the same insecticide group, the difference in toxicity to boll weevils and natural enemies is presented and discussed. Ethiprole was more toxic to boll weevils than to its parasitoid and lady beetle, and isocycloseram was highly toxic to all three species.
Assuntos
Inseticidas , Gorgulhos , Animais , Gorgulhos/efeitos dos fármacos , Isoxazóis/toxicidade , Pirazóis/toxicidade , Besouros/efeitos dos fármacosRESUMO
The fungal diglycosidase α-rhamnosyl-ß-glucosidase I (αRßG I) from Acremonium sp. DSM 24697 catalyzes the glycosylation of various OH-acceptors using the citrus flavanone hesperidin. We successfully applied a one-pot biocatalysis process to synthesize 4-methylumbellipheryl rutinoside (4-MUR) and glyceryl rutinoside using a citrus peel residue as sugar donor. This residue, which contained 3.5 % [w/w] hesperidin, is the remaining of citrus processing after producing orange juice, essential oil, and peel-juice. The low-cost compound glycerol was utilized in the synthesis of glyceryl rutinoside. We implemented a simple method for the obtention of glyceryl rutinoside with 99 % yield, and its purification involving activated charcoal, which also facilitated the recovery of the by-product hesperetin through liquid-liquid extraction. This process presents a promising alternative for biorefinery operations, highlighting the valuable role of αRßG I in valorizing glycerol and agricultural by-products. KEYPOINTS: ⢠αRßG I catalyzed the synthesis of rutinosides using a suspension of OPW as sugar donor. ⢠The glycosylation of aliphatic polyalcohols by the αRßG I resulted in products bearing a single rutinose moiety. ⢠αRßG I catalyzed the synthesis of glyceryl rutinoside with high glycosylation/hydrolysis selectivity (99 % yield).
Assuntos
Acremonium , Hesperidina , Hesperidina/química , GlicerolRESUMO
The aim of the present study was to assess the selectivity of herbicides applied in the pre and post-planting of pre-sprouted seedlings (PSS). The experiment was conducted in a greenhouse, using a completely randomized design, with nine treatments and four repetitions. The IACSP95-5000 cultivar was used. The treatments consisted of herbicides applied in five doses as follows: in pre-planting: sulfentrazone, diclosulam, imazapic, and imazapyr, in post-planting: ethoxysulfuron, halosulfuron, 2,4-D and MSMA, and a control treatment without herbicide. Injury symptoms were assessed at 7, 15, 30, 45, 60, 75, and 90 days after application (DAA), height, diameter, number of tillers, chlorophyll A, B, and total chlorophyll at 30, 60, and 90 DAA, leaf area, shoot and root dry mass at 90 DAA. The post-emergent herbicides were considered selective. Pre-planting herbicides reduced the variables assessed at 90 DAA, observed by linear regression for diclosulam and imazapic, and exponential regression for imazapyr. Treatments with sulfentrazone caused few injury symptoms, with subsequent recovery. In addition, all the variables analyzed were equal to control, with the sulfentrazone considered selective for the IACSP95-5000 cultivar.
Assuntos
Herbicidas , Saccharum , Sulfonamidas , Triazóis , Clorofila , Plântula , Clorofila ARESUMO
OBJECTIVE: To examine clinical correlates and prevalence of food selectivity (FS) - ie, self-restricted diet, reluctance to try new foods - in children with autism spectrum disorder (ASD) ascertained from a general outpatient autism clinic. STUDY DESIGN: A multidisciplinary team (pediatric nurse practitioner, psychologist and dietitian) assessed medical and psychosocial histories and dietary habits in 103 children with ASD (mean age = 5.8 ± 2.2 years; range 2-10). Parents rated child mealtime behavior on the Brief Autism Mealtime Behavior Inventory (BAMBI) and disruptive behavior on the Aberrant Behavior Checklist (ABC). Height and weight measurements were collected. Children were classified as FS or no FS based on parent reported intake and mealtime behavior. A 24-hour dietary recall was used to record intake percentages < 80%. Logistic regression and multivariable modeling were used to evaluate clinical correlates with FS. RESULTS: Of 103 children, 45.6% (n = 47) were classified as FS; 54.4% (n = 56) no FS. After adjusting for potential confounders, the odds of FS increased by 1.91 (95% CI: 1.38, 2.64, P < .001) for every half-SD increase in BAMBI total score and by 1.35 (95% CI: 1.05, 1.74, P = .020) for every half-SD increase in ABC Hyperactivity/Noncompliance. No group differences in anthropometrics or nutritional intake were identified. CONCLUSIONS: Food selectivity (FS) in children with ASD was strongly associated with greater severity of disruptive mealtime and hyperactivity/noncompliance behaviors. FS was not associated with anthropometrics or nutritional intake.
Assuntos
Transtorno do Espectro Autista , Humanos , Transtorno do Espectro Autista/psicologia , Transtorno do Espectro Autista/epidemiologia , Masculino , Feminino , Criança , Pré-Escolar , Prevalência , Comportamento Alimentar , Preferências AlimentaresRESUMO
A feeding therapy developed in Brazil integrates aspects from diverse approaches and has increasingly been acknowledged as an adjunctive approach for addressing childhood feeding difficulties. In children, problems with eating are a common issue that affects their nutritional well-being, health, and overall quality of life, and can greatly hinder their social, emotional, and physical growth. In the realm of pediatrics, feeding therapy uses food and nutritional education, interactive games, and activities tailored to age groups and individualized treatment plans. The primary objective is to transform mealtime experiences and gradually foster children's acceptance of previously rejected foods. However, this treatment approach is new and recent in Brazil and lacks studies that explore and elucidate the topic. Therefore, this report aims to describe the follow-up and effects of feeding therapy in a 3-y and 8-mo-old neurotypical male patient with feeding difficulties who underwent feeding therapy conducted by a dietitian over a period of 19 wk. The feeding therapy consisted of 45-min sessions once a week in which food and nutrition education activities, games, and interactive activities, personalized according to the treatment plan, were carried out. The effects of feeding therapy were evaluated according to the patient's feeding progression throughout the sessions and their stepwise progress in the eating hierarchy. Based on our observations, the findings of this study suggest that feeding therapy practiced in Brazil can be a viable treatment approach for addressing feeding difficulties within this population. The feeding therapy originated in Brazil stands out from traditional nutritional care with its nurturing and compassionate approach that prioritizes respect for the child.
Assuntos
Comportamento Alimentar , Qualidade de Vida , Humanos , Criança , Masculino , Comportamento Alimentar/psicologia , Emoções , Educação em Saúde , AlimentosRESUMO
Reduced-risk insecticides and mirid predators have been used to control Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in tomato crops. However, even when causing low mortality to the beneficial insects, these products might cause side effects. This study investigated the sublethal and transgenerational effects of buprofezin, cyantraniliprole, and spiromesifen on Macrolophus basicornis (Stal) (Hemiptera: Miridae). After 72 h of exposure of third-instar nymphs and adults to residues on tomato leaves, adult couples were formed and kept in cages with residue-free tomato leaves. The leaves were changed every 48 h and the offspring were assessed in 6 different periods. Body size was assessed by measuring the hind-tibia length of adults (F0) from exposed nymphs and in three different offspring groups. None of the insecticide residues caused a reduction on offspring populations or affected the body size of adults in generation F0. Regardless, buprofezin and spiromesifen reduced the tibia length of adults (F1) from exposed nymphs assayed in the third mating period. Cyantraniliprole did not affect any parameter and could be recommended for control of B. tabaci in association with M. basicornis releases. This study may contribute to future field assays of the compatibility of these insecticides with M. basicornis.