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1.
Int J Biol Macromol ; 274(Pt 1): 133283, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38909731

RESUMO

Metastatic melanoma is highly aggressive and challenging, often leading to a grim prognosis. Its progression is swift, especially when mutations like BRAFV600E continuously activate pathways vital for cell growth and survival. Although several treatments target this mutation, resistance typically emerges over time. In recent decades, research has underscored the potential of snake venoms and peptides as bioactive substances for innovative drugs, including anti-coagulants, anti-microbial, and anti-cancer agents. Leveraging this knowledge, we propose employing a bioinformatics simulation approach to: a) Predict how well a peptide (DisBa01) from Bothrops alternatus snake venom binds to the melanoma receptor BRAFV600E via Molecular Docking. b) Identify the specific peptide binding sites on receptors and analyze their proximity to active receptor sites. c) Evaluate the behavior of resulting complexes through molecular dynamics simulations. d) Assess whether this peptide qualifies as a candidate for anti-melanoma therapy. Our findings reveal that DisBa01 enhances stability in the BRAFV600E melanoma receptor structure by binding to its RGD motif, an interaction absent in the BRAF WT model. Consequently, both docking and molecular dynamics simulations suggest that DisBa01 shows promise as a BRAFV600E inhibitor.


Assuntos
Bothrops , Melanoma , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Proteínas Proto-Oncogênicas B-raf , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/química , Proteínas Proto-Oncogênicas B-raf/metabolismo , Animais , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Melanoma/patologia , Humanos , Ligação Proteica , Peptídeos/química , Peptídeos/farmacologia , Sítios de Ligação , Serpentes Peçonhentas
2.
Int J Biol Macromol ; 231: 123367, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36690229

RESUMO

Despite advances in treating patients with melanoma, there are still many treatment challenges to overcome. Studies with snake venom-derived proteins/peptides describe their binding potential, and inhibition of some proliferative mechanisms in melanoma. The combined use of these compounds with current therapies could be the strategic gap that will help us discover more effective treatments for melanoma. The present study aimed to carry out a systematic review identifying snake venom proteins and peptides described in the literature with antitumor, antimetastatic, or antiangiogenic effects on melanoma and determine the mechanisms of action that lead to these anti-tumor effects. Snake venoms contain proteins and peptides which are antiaggregant, antimetastatic, and antiangiogenic. The in vivo results are encouraging, considering the reduction of metastases and tumor size after treatment. In addition to these results, it was reported that these venom compounds could act in combination with chemotherapeutics (Acurhagin-C; Macrovipecetin), sensitizing and preparing tumor cells for treatment. There is a consensus that snake venom is a promising strategy for the improvement of antimelanoma therapies, but it has been little explored in the current context, combined with inhibitors, immunotherapy or tumor microenvironment, for example. We suggest Lebein as a candidate for combination therapy with BRAF inhibitors.


Assuntos
Melanoma , Venenos de Serpentes , Humanos , Venenos de Serpentes/química , Melanoma/patologia , Peptídeos , Inibidores da Angiogênese , Microambiente Tumoral
3.
Artigo em Inglês | MEDLINE | ID: mdl-33220513

RESUMO

Sea anemones of the genus Bunodosoma possess along their body column, longitudinally arranged brown-colored vesicles. We have shown that in B. cangicum, these warty structures contain a mixture of potent toxins. This work highlights the neuro-inhibitory effects exhibited by two decapod crustacean species exposed to the extracts from these vesicles. For this, we use the unrefined toxin in doses, exposure times, and different exposure pathways. The findings show that at least one neuro-inhibitory compound is present and remains active regardless of the exposure method or dose tested. This toxin affects neuro-motor pathways but not neuro-sensory pathways. Shrimp exposed to toxin could continue to perceive and track food pellets but could not secure and consume their ration. Of six anatomical reflexes tested under the toxin's influence, voluntary movements of the mouthparts were impacted most commonly. Interestingly, all subject animals recovered from the toxin exposure within 2 h. Finally, we propose Reflexive Action Analysis (RAMP) as a tool to evaluate the potency of other neurotoxic or neuro-inhibitory compounds in crustacea. This work is the first to show the neuro-inhibitory activity of extracts from these sea anemone columnar vesicle structures and the first to evaluate these effects using RAMP reflex analysis.


Assuntos
Comportamento Animal/efeitos dos fármacos , Braquiúros/efeitos dos fármacos , Venenos de Cnidários/toxicidade , Palaemonidae/efeitos dos fármacos , Anêmonas-do-Mar/química , Animais , Braquiúros/fisiologia , Água Doce/química , Monitorização Neurofisiológica/métodos , Palaemonidae/fisiologia , Anêmonas-do-Mar/metabolismo , Alimentos Marinhos
4.
Ciênc. rural (Online) ; 48(7): e20170921, 2018. tab
Artigo em Inglês | LILACS | ID: biblio-1045174

RESUMO

ABSTRACT: The aim of this study was to estimate neosporosis seroprevalence and its associated risk factors in milk herds (Bos taurus taurus) located in the northwestern region of Rio Grande do Sul State, Brazil. Three hundred twenty-two blood samples were collected from dairy cows on 18 farms in 17 cities of this region. An epidemiologic questionnaire was completed for each farm. It consisted of questions about the general characteristics of the herd, reproduction, and animal management. Serum samples were tested for Neospora caninum using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Results indicated a seroprevalence of Neospora in 88.9% (16/18) of herds and 31.1% (100/322) of individuals. Risk factor analyses demonstrated that culling by reproductive disorder (OR = 0.6), flooding (OR = 0.5), and commercial sale (OR = 0.4) were associated with seroprevalence. Nevertheless, the purchase of replacement animals in the herd played an important role in disease occurrence (OR = 2.2). Results of this study suggested that Neospora caninum was present in the studied herds under investigation and that there are risk factors associated with its seroprevalence on the farms of the northwestern of Rio Grande do Sul.


RESUMO: O objetivo desse estudo foi estimar a soroprevalência da neosporose e os possíveis fatores de risco em rebanhos (Bos taurus taurus) localizados na mesorregião Noroeste do Rio Grande do Sul, Brasil. Foram coletadas 322 amostras de sangue de bovinos leiteiros, em 18 propriedades localizadas em 17 munícipios desta mesorregião. Um questionário epidemiológico foi aplicado em cada propriedade, contendo questões relacionadas às características gerais dos rebanhos, dados reprodutivos e manejo animal. As amostras de soro foram testadas através do teste de imunoensaio enzimático (ELISA) para Neospora caninum. Os resultados demonstraram uma soroprevalência de Neospora de 88,9% (16/18) entre os rebanhos e 31,1% (100/322) entre os indivíduos. Entre os fatores de risco analisados foi observado que descarte por problemas reprodutivos (OR=0,6), presença de áreas alagadiças (OR=0,5) e venda comercial (OR=0,4) estavam associados a soroprevalência. No entanto, a compra de animais substituídos no rebanho desempenhou um papel significativo na ocorrência da doença (OR=2,2). Os resultados desse estudo sugerem que o Neospora caninum esteve presente nos rebanhos estudados, bem como, existem fatores associados com a soroprevalência nas propriedades da mesorregião do Noroeste do Rio Grande do Sul.

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