EFEITO DA FRAÇÃO HEXANO DAS FOLHAS DE Selaginella sellowii Hieron SOBRE A HEMOSTASIA HUMANA

Abstract

The species Selaginella sellowii Hieron is a lycophyte belonging to the family Selaginellaceae, also found in the Brazilian Midwest, characterized by a high adaptive capacity and a significant presence of secondary metabolites in its extracts, such as biflavonoids and flavonoids, which exhibit antioxidant activity. There are reports of its traditional use as an anti-hemorrhagic agent, among other popular applications, as well as studies involving other Selaginella species regarding their hemostatic activity. Therefore, it becomes relevant to investigate the hexane fraction of the S. sellowii leaf extract on human hemostasis, considering that imbalances in this process may lead to thrombus formation or hemorrhages, resulting in arterial and venous obstruction and potentially fatal complications such as acute myocardial infarction, pulmonary thromboembolism, and cerebrovascular accident. The objective of this study was to evaluate the effect of the hexane fraction of S. sellowii extract on human hemostasis. Human plasma was used, collected from healthy adult volunteers (both sexes) with approval from the ethics committee. Initially, an in vitro toxicity assay using trypan blue was performed, evaluating concentrations ranging from 50 to 1000μg/mL in serial dilution. Subsequently, using only the concentrations of 50, 200, and 800μg/mL, platelet aggregation and blood coagulation assays were conducted by turbidimetry, as well as platelet activation capacity by fluorimetry (measuring the generation of reactive oxygen species – ROS). Data were statistically analyzed by analysis of variance (ANOVA), followed by the Tukey-Kramer test, with a significance level of p < 0.05. The extract demonstrated safety toward human platelets, as platelet viability remained above 80% at all tested concentrations. A reduction in platelet aggregation of 14%, 18%, and 22% was observed at concentrations of 50 μg/mL, 200 μg/mL, and 800 μg/mL, respectively. The extract did not alter coagulation parameters at any of the tested concentrations, nor did it significantly reduce ROS production after 10 minutes of incubation. Therefore, the hexane extract from S. sellowii leaves exhibited potential antiplatelet activity. Based on these findings, further research with the hexane extract is warranted to elucidate its mechanism of action in the human organism.