RESUMO
Abstract The use of Echinacea purpurea (EP), a plant native from North America, is widely diffused throughout the world, presenting many pharmacological applications, mainly for the treatment of infections of respiratory and urinary tracts. Due to the widespread commercialization of EP-based products, an effective evaluation of their pharmacological properties is essential to assure efficacy during clinical use. In this study, in vitro tests were performed to evaluate the antimicrobial activity of dried extracts of EP by the microdilution method. In addition, a phagocytosis model was employed to assess the immunomodulatory potential of the extracts. The increase in reactive oxygen species production, as well as the intracellular proliferation rate of Cryptococcus gatti after phagocytosis by macrophages in the presence of EP dried extracts were also evaluated. The analyzed samples showed no significant antibacterial activity; however, a slight antifungal activity was verified. Positive effects of EP extracts on the modulation of cellular immune response were observed in different experiments, indicating that this mechanism may contribute to the control and treatment of infections.
RESUMO
ABSTRACT Major health challenges as the increasing number of cases of infections by antibiotic multiresistant microorganisms and cases of Alzheimer's disease have led to searching new control drugs. The present study aims to verify a new way of obtaining bioactive extracts from filamentous fungi with potential antimicrobial and acetylcholinesterase inhibitory activities, using epigenetic modulation to promote the expression of genes commonly silenced. For such finality, five filamentous fungal species (Talaromyces funiculosus, Talaromyces islandicus, Talaromyces minioluteus, Talaromyces pinophilus, Penicillium janthinellum) were grown or not with DNA methyltransferases inhibitors (procainamide or hydralazine) and/or a histone deacetylase inhibitor (suberohydroxamic acid). Extracts from T. islandicus cultured or not with hydralazine inhibited Listeria monocytogenes growth in 57.66 ± 5.98% and 15.38 ± 1.99%, respectively. Increment in inhibition of acetylcholinesterase activity was observed for the extract from P. janthinellum grown with procainamide (100%), when compared to the control extract (39.62 ± 3.76%). Similarly, inhibition of acetylcholinesterase activity increased from 20.91 ± 3.90% (control) to 92.20 ± 3.72% when the tested extract was obtained from T. pinophilus under a combination of suberohydroxamic acid and procainamide. Concluding, increases in antimicrobial activity and acetylcholinesterase inhibition were observed when fungal extracts in the presence of DNA methyltransferases and/or histone deacetylase modulators were tested.