Avaliação do extrato de Physalis angulata sobre larvas do carrapato Rhipicephalus (Boophilus) Microplus

The tick Rhipicephalus (Boophilus) microplus is responsible for large losses in livestock worldwide, causing a drop in meat and milk production, leather depreciation, annoyance to animals and transmission of hemoparasitosis that can lead to death. The control of this ectoparasite is currently carried out by synthetic chemical compounds, however, most with reported cases of resistance, makes it necessary to study new natural alternatives necessary. The present study aimed to evaluate the Physalis angulata extract between concentrations 100 - 12.5 mg mL-1 on R. (B.) microplus larvae by the impregnated paper patch test (IPPT). The results were promising and the concentrations of 100 and 50 mg mL-1 were the most effective, presenting 92.24% and 58.47% of larval mortality, respectively.La garrapata Rhipicephalus (Boophilus) microplus es responsable de grandes pérdidas en el ganado a nivel mundial, provocando caída en la producción de carne y leche, depreciación del cuero, molestias a los animales y transmisión de hemoparasitosis que puede llegar a causar la muerte. El control de este ectoparásito actualmente se realiza mediante compuestos químicos de síntesis, sin embargo, la mayoría con casos reportados de resistencia, hace necesario el estudio de nuevas alternativas naturales. El presente estudio tuvo como objetivo evaluar el extracto de Physalis angulata entre concentraciones de 100 - 12,5 mg mL-1 sobre larvas de R. (B.) microplus mediante la prueba del parche de papel impregnado (TCPI). Los resultados fueron promisorios y las concentraciones de 100 y 50 mg mL-1 fueron las más efectivas, presentando 92,24% y 58,47% de mortalidad larvaria, respectivamente.O carrapato Rhipicephalus (Boophilus) microplus é responsável por grandes perdas na pecuária mundial, causando queda na produção de carne e leite, depreciação do couro, incômodo aos animais e transmissão de hemoparasitoses que podem levar os animais a óbito. O controle desse ectoparasita atualmente é realizado por compostos químicos sintéticos, porém, a maioria com casos de resistência relatados, torna necessário o estudo de novas alternativas naturais necessárias. O presente trabalho teve como objetivo avaliar o extrato de Physalis angulata entre as concentrações 100 - 12,5 mg mL-1 sobre larvas de R. (B.) microplus pelo teste de contato em papel impregnado (TCPI). Os resultados se mostraram promissores sendo as concentrações 100 e 50 mg mL-1 as mais efetivas apresentando 92,24% e 58,47% de mortalidade das larvas respectivamente

Coating of surgical masks with quaternized chitosan aiming at inactivating coronavirus and antibacterial activity

SARS-CoV-2 caused a global pandemic with high transmission rates, even with widespread vaccination. In addition to isolation and prevention measures, it is important to find new solutions to inactivate the virus and prevent its viability on surfaces, such as clothing and face masks. Chitosan derivatives, with their antibacterial activity, biocompatibility, and non-toxicity, are a promising option for coating these components with virucidal materials. N-(2-hydroxypropryl)-3-trimethylammonium chloride, a quaternized chitosan derivative with degrees of substitution ranging from 59 to 93%, was synthesized. This derivative was used to coat cotton and polypropylene fabrics, such as face masks, without visibly affecting their morphology or filtering capacity. In vitro tests demonstrated that the coatings produced had high antiviral activity against coronavirus, with efficacy up to 99.99%, and were also bactericidal against E. coli and S. aureus. These results show that quaternized chitosan derivatives have great potential to be used as virucidal coatings, helping to prevent the spread of SARS-Cov-2 and other pathogens on surfaces, which can even be useful for the quick development of solutions for future pandemics

Evaluating the microbicidal, antiparasitic and antitumor effects of CR-LAAO from Calloselasma rhodostoma venom

CR-LAAO is an l-amino acid oxidase from Calloselasma rhodostoma snake venom that has been broadly studied regarding its structural and biochemical characteristics, however, few studies have investigated its pharmacological effects. The present study aimed at the evaluation of the biotechnological potential of CR-LAAO by determining its bactericidal, antifungal, leishmanicidal and trypanocidal activity, as well as its cytotoxicity on human tumor and non-tumor cell lines. After 24h of preincubation, CR-LAAO showed bactericidal effects against both Staphylococcus aureus (MIC 0.78μg/mL) and Escherichia coli (MIC 31.25μg/mL) strains, inducing dismantle of bacterial cell walls. After 6h of preincubation with Candida albicans, CR-LAAO was able to inhibit 80% of the yeast growth, and it also showed cytotoxic activity on Leishmania species and Trypanosoma cruzi. Additionally, CR-LAAO showed high cytotoxicity on HepG2 and HL-60 tumor cells (IC50 10.78 and 1.7μg/mL), with lower effects on human mononuclear cells (PBMC). The cytotoxic effects of CR-LAAO were significantly inhibited in the presence of catalase, which suggests the involvement of hydrogen peroxide in its mechanisms of toxicity. Therefore, CR-LAAO showed promising pharmacological effects, and these results provide important information for the development of therapeutic strategies with directed action, such as more effective antimicrobial agents

Poly-ε-caprolactone Nanoparticles Loaded with 4-Nerolidylcatechol (4-NC) for Growth Inhibition of Microsporum canis

Dermatophyte fungal infections are difficult to treat because they need long-term treatments. 4-Nerolidylcatechol (4-NC) is a compound found in Piper umbellatum that has been reported to demonstrate significant antifungal activity, but is easily oxidizable. Due to this characteristic, the incorporation in nanostructured systems represents a strategy to guarantee the compound’s stability compared to the isolated form and the possibility of improving antifungal activity. The objective of this study was to incorporate 4-NC into polymeric nanoparticles to evaluate, in vitro and in vivo, the growth inhibition of Microsporum canis. 4-NC was isolated from fresh leaves of P. umbellatum, and polymer nanoparticles of polycaprolactone were developed by nanoprecipitation using a 1:5 weight ratio (drug:polymer). Nanoparticles exhibited excellent encapsulation efficiency, and the antifungal activity was observed in nanoparticles with 4-NC incorporated. Polymeric nanoparticles can be a strategy employed for decreased cytotoxicity, increasing the stability and solubility of substances, as well as improving the efficacy of 4-NC