RESUMO
Rhipicephalus microplus, is one parasites that cause severe productivity losses in the cattle industry of Brazil and shows increasing resistance to conventional pesticides. This research aims to study the chemical composition, and acaricidal activity of the essential oil from Ocotea notata leaves, a brazilian endemic species, against R. microplus. The effect on R. microplus engorged adult females was evaluated using the immersion test. The oil reduced the survival by 90% after incubation for 15 days and there was 100% reduction for posture inhibition and reproductive capacity. These results suggest that the O. notata essential oil has activity on the R. microplus.
Rhipicephalus microplus, es un parásito que causa graves pérdidas de productividad en la industria ganadera de Brasil y muestra una creciente resistencia a los pesticidas convencionales. Esta investigación tiene como objetivo estudiar la composición química y la actividad acaricida del aceite esencial de las hojas de Ocotea notata, una especie endémica brasileña, contra R. microplus. El efecto sobre las hembras adultas engordadas de R. microplus se evaluó mediante la prueba de inmersión. El aceite redujo la supervivencia en 90% después de la incubación durante 15 días y hubo una reducción del 100% para la inhibición de la postura y la capacidad reproductiva. Estos resultados sugieren que el aceite esencial de O. notata tiene actividad contra R. microplus.
Assuntos
Animais , Óleos Voláteis/farmacologia , Ocotea/química , Rhipicephalus/efeitos dos fármacos , Acaricidas/farmacologia , Terpenos/análise , Carrapatos/efeitos dos fármacos , Brasil , Óleos Voláteis/química , Controle de Ácaros e Carrapatos/métodos , Folhas de Planta/química , Lauraceae/química , Acaricidas/química , Cromatografia Gasosa-Espectrometria de MassasRESUMO
Snake venoms are composed of a complex mixture of active proteins that induce toxic effects, such as edema, hemorrhage, and death. Lachesis muta has the highest lethality indices in Brazil. In most cases, antivenom fails to neutralize local effects, leading to disabilities in victims. Thus, alternative treatments are under investigation, and plant extracts are promising candidates. The objective of this work was to investigate the ability of crude extracts, fractions, or isolated products of Erythroxylum ovalifolium and Erythroxylum subsessile to neutralize some toxic effects of L. muta venom. All samples were mixed with L. muta venom, then in vivo (hemorrhage and edema) and in vitro (proteolysis, coagulation, and hemolysis) assays were performed. Overall, crude extracts or fractions of Erythroxylum spp. inhibited (20%-100%) toxic effects of the venom, but products achieved an inhibition of 4%-30%. However, when venom was injected into mice before the plant extracts, hemorrhage and edema were not inhibited by the samples. On the other hand, an inhibition of 5%-40% was obtained when extracts or products were given before venom injection. These results indicate that the extracts or products of Erythroxylum spp. could be a promising source of molecules able to treat local toxic effects of envenomation by L. muta venom, aiding in the development of new strategies for antivenom treatment.
Assuntos
Misturas Complexas/farmacologia , Magnoliopsida/química , Extratos Vegetais/farmacologia , Venenos de Serpentes/antagonistas & inibidores , Viperidae/metabolismo , Animais , Coagulação Sanguínea/efeitos dos fármacos , Misturas Complexas/química , Edema/induzido quimicamente , Edema/tratamento farmacológico , Hemólise/efeitos dos fármacos , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Técnicas In Vitro , Camundongos , Extratos Vegetais/química , Venenos de Serpentes/toxicidadeRESUMO
The worldwide distribution of herpes simplex virus type 1 (HSV-1) allied to the emergence of resistant strains makes necessary and urgent the search and development of new substances capable of preventing and treating HSV-1 infections. Studies demonstrate synergy between genital herpes and human immunodeficiency virus type 1 (HIV-1), which represents a major concern for global public health. Objective: The objective of this study was to evaluate the activity of crude extracts and isolated substances from C. fluminensis in the in vitro replication of the HSV-1 virus and HIV-1-RT activity. Methods: This study evaluated the activity of extracts and isolated compounds from Clusia fluminensis Planch. & Triana against HSV-1 using Vero cells in culture and against HIV-1 using a recombinant reverse transcriptase enzyme (HIV -1 RT). The percentage of inhibition against HSV-1 was determined from viral lysis plaque reduction assay, and the anti-HIV-1-RT test was performed by a fluorimetric assay. It was also evaluated the cytotoxic activity of the samples using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]. Results: The crude extracts showed high percentage of inhibition against HSV-1, reaching 81.4 to 100.0% inhibition in non-cytotoxic concentration (50 µg/mL). The isolated compounds, lanosterol and clusianone, demonstrated 100% inhibition in non-cytotoxic concentration (50 µg/mL). We also examined the effects of the extracts and isolates on the activity of the HIV-1-RT. Among the crude extracts, only the methanolic extract of leaves and methanolic extract of stems showed inhibitory activity against HIV-1-RT. Regarding the isolated compounds, lanosterol showed a moderate activity. Conclusion: Our data demonstrate that extracts and isolates compounds Clusia fluminensis Planch. & Triana have promising antiviral activity inhibiting HSV-1 replication and HIV-1 by inhibiting the anti-RT activity.
A distribuição mundial do vírus herpes simplex tipo 1 (HSV-1) aliada ao surgimento de cepas resistentes torna necessária e urgente a busca e o desenvolvimento de novas substâncias capazes de prevenir e tratar infecções HSV-1. Estudos demonstram sinergia entre herpes genital e vírus da imunodeficiência humana tipo 1 (HIV-1), o que representa uma grande preocupação para a saúde pública global. Objetivo: O objetivo deste estudo foi avaliar a atividade de extratos brutos e substâncias isoladas de Clusia fluminensis Planch. & Triana na replicação in vitro do vírus HSV-1 e na atividade anti HIV-1-RT. Métodos: Este estudo avaliou a atividade de extratos e substâncias isoladas de Clusia fluminensis Planch. & Triana contra o HSV-1 utilizando células Vero em cultura e contra o HIV-1 utilizando a enzima transcriptase reversa recombinante (HIV-1 RT). A porcentagem de inibição contra o HSV-1 foi determinada a partir do ensaio de redução de placas de lise viral, e o ensaio anti-HIV-1 RT foi realizado por um ensaio fluorimétrico. Também foi avaliada a atividade citotóxica das amostras utilizando MTT [brometo de 3- (4,5-dimetiltiazol-2-il) -2,5-difeniltetrazólio]. Resultados: Os extratos demonstraram elevada percentagem de inibição contra o HSV-1, atingindo 81,4 a 100,0% de inibição em concentração não citotóxica (50 µg/mL). Os compostos isolados, lanosterol e clusianona, demonstraram 100% de inibição em concentração não citotóxica (50 µg/mL). Examinamos também os efeitos dos extratos e isolados sobre a atividade anti-HIV-1 RT. Entre os extratos brutos, apenas o extrato metanólico das folhas e caules apresentaram atividade anti-HIV-1 RT. Em relação aos compostos isolados, lanosterol mostrou uma atividade moderada. Conclusão: Nossos dados demonstram que os extratos e compostos isolados de Clusia fluminensis Planch. & Triana possuem atividade antiviral promissora inibindo a replicação do HSV-1 e HIV-1 através da inibição da atividade anti-RT.
