RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Casearia sylvestris is a medicinal plant traditionally used to treat snakebites, wounds, inflammation and gastric ulcers and scientific supports for have demonstrated its antitumor, antihyperlipidemic and antiparasitic properties. AIM OF THE STUDY: To assess the effects of a fraction with casearins (FC) on adult mice using classical experimental models of animal behavior and theoretical calculations to verify the interaction of Casearin X (Cas X) with neuron receptors. MATERIALS AND METHODS: Animals divided in 6 groups (n=9/group) were intraperitoneally treated with vehicle (DMSO 4%), FC (2.5, 5, 10 and 25mg/kg/day) and diazepam (2mg/kg) for 7 days. Thirty minutes after the last dose of treatment, acute toxicity and behavioral experiments were performed. RESULTS: The highest dose of FC (25mg/kg/day) caused diarrhea, weight loss and death of one animal. Elevated plus maze test showed that lower doses [2.5mg/kg/day (36.4±5.1s) and 5mg/kg/day (43.9±6.2s)] increased the time spent in open arms (TSOA). Open field test revealed reduction in the number of crossings (54.9%, 51.1%, 48% and 67.7% for 2.5, 5, 10 and 25mg/kg/day, respectively) in all doses of FC studied and decrease of rearings at 25mg/kg/day (p<0.05). Computational calculations showed that the inhibition constant (Ki) for the Cas X-D1 complex is up to 1000-fold more favourable than the Cas X-GABAA complex. All ∆G° values obtained for Cas X-D1 complexes were more negative than those seen with Cas X-GABAA complexes. CONCLUSIONS: Findings indicate a probable anxiolytic action of the FC since it reduces the number of crossings and rearings and prolonged the time spent in open arms, without sedative and myorelaxant effects, probably due to the interaction of Cas X with dopaminergic system.
Assuntos
Comportamento Animal/efeitos dos fármacos , Casearia/química , Diterpenos/farmacologia , Extratos Vegetais/farmacologia , Animais , Ansiolíticos/administração & dosagem , Ansiolíticos/isolamento & purificação , Ansiolíticos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Simulação por Computador , Diazepam/farmacologia , Diterpenos/administração & dosagem , Diterpenos/isolamento & purificação , Dopamina/metabolismo , Relação Dose-Resposta a Droga , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Neurônios/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/toxicidadeRESUMO
Cancer is a public health problem which represents the second cause of death in the world. In this framework, it is necessary to identify novel compounds with antineoplastic potential. Plants are an important source for discovering novel compounds with pharmacological potential. In this study, we aimed to investigate the antiproliferative potential of isolated compounds from Casearia sylvestris on tumor cell lines. Crude extract effectively reduced cell viability of 4 tumor cell lines (HepG2, A549, U251-MG, and HT-144) after 48h treatment. HepG2 and HT-144 were the most responsive cells. Three fractions (aqueous ethanol, n-hexane and ethyl acetate) were tested against HepG2 and HT-144 cells and we observed that compounds with antiproliferative activity were concentrated in n-hexane and ethyl acetate fractions. The casearins A, G and J were isolated from n-hexane fraction, while casearin D was obtained from ethyl acetate fraction. We demonstrated that casearin D significantly inhibited the clonogenic capacity of HepG2 cells after 24h exposure indicating its antiproliferative activity. In addition, G1/S transition cell cycle arrest in HepG2 cells was also observed. These effects are related, at least in part, to ability of the casearin D in reducing ERK phosphorylation and cyclin D1 expression levels.
Assuntos
Antineoplásicos/farmacologia , Ciclina D1/metabolismo , Diterpenos Clerodânicos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Casearia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Diterpenos Clerodânicos/isolamento & purificação , Regulação para Baixo/efeitos dos fármacos , Humanos , Testes para Micronúcleos , Fosforilação/efeitos dos fármacos , Extratos Vegetais/química , Folhas de PlantaRESUMO
Leishmaniasis and Chagas disease are infectious diseases caused by parasite Leishmania sp. and Trypanosoma cruzi, respectively, and are included among the most neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antiparasitic potential of MeOH extract from leaves of Casearia sylvestris Sw. (Salicaceae), a bioguided fractionation was conducted and afforded four active clerodane diterpenes (casearins A, B, G, and J). The obtained results indicated a superior efficacy of tested casearins against trypomastigotes of T. cruzi, with IC50 values ranging from 0.53 to 2.77 µg/ml. Leishmania infantum promastigotes were also susceptible to casearins, with IC50 values in a range between 4.45 and 9.48 µg/ml. These substances were also evaluated for mammalian cytotoxicity against NCTC cells resulting in 50% cytotoxic concentrations (CC50) ranging from 1.46 to 13.76 µg/ml. Additionally, the action of casearins on parasite membranes was investigated using the fluorescent probe SYTOX Green. The obtained results demonstrated a strong interaction of casearins A and B to the plasma membrane of T. cruzi parasites, corroborating their higher efficacy against these parasites. In contrast, the tested casearins induced no alteration in the permeability of plasma membrane of Leishmania parasites, suggesting that biochemical differences between Leishmania and T. cruzi plasma membrane might have contributed to the target effect of casearins on trypomastigotes. Thus, considering the importance of studying novel and selective drug candidates against protozoans, casearins A, B, G, and J could be used as tools to future drug design studies.