RESUMO
Biomedical application of silver nanoparticles (AgNPs) has been rapidly increasing. Owing to their strong antimicrobial activity, AgNPs are used in dermatology in the treatment of wounds and burns. However, recent evidence for their cytotoxicity gives rise to safety concerns. This study was undertaken as a part of an ongoing programme in our laboratory to develop a topical agent for wound healing. Here, we investigated the potential toxicity of AgNPs using normal human dermal fibroblasts (NHDF) and normal human epidermal keratinocytes (NHEK) with the aim of comparing the effects of AgNPs and ionic silver (Ag-I). Besides the effect of AgNPs and Ag-I on cell viability, the inflammatory response and DNA damage in AgNPs and Ag-I-treated cells were examined. The results showed that Ag-I were significantly more toxic than AgNPs both on NHDF and NHEK. Non-cytotoxic concentrations of AgNPs and Ag-I did not induce DNA strand breaks and did not affect inflammatory markers, except for a transient increase in interleukin 6 levels in Ag-I-treated NHDF. The results showed that AgNPs are more suitable for the intended application as a topical agent for wound healing up to the concentration 25 µg/mL.
Assuntos
Anti-Infecciosos/toxicidade , Fibroblastos/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Pele/efeitos dos fármacos , Anti-Infecciosos/química , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Dano ao DNA , Relação Dose-Resposta a Droga , Epiderme/efeitos dos fármacos , Epiderme/patologia , Fibroblastos/patologia , Humanos , Queratinócitos/patologia , Nanopartículas Metálicas/química , Microscopia Eletrônica de Transmissão , Prata/química , Pele/patologia , Propriedades de SuperfícieRESUMO
2,3-Dehydrosilybin exhibits substantial anticancer and antiangiogenic effects, which can be potentially improved by semi-synthetic modification such as esterification with gallic acid. The aim of this study was to examine the potential antiangiogenic effect of 2,3-dehydrosilybin and its galloyl esters (3-O-galloyl-2,3-dehydrosilybin; 7-O-galloyl-2,3-dehydrosilybin; 20-O-galloyl-2,3-dehydrosilybin and 23-O-galloyl-2,3-dehydrosilybin) and to determine which molecular mechanism could be responsible for their activity. The effect on cell proliferation, tube formation, signal transduction pathways (PI3K/Akt and ERK) and the cell cycle was studied in human microvascular endothelial cells (HMEC). The results showed that all compounds decreased the growth of HMEC, but the strongest effect was observed for 20-O-galloyl-2,3-dehydrosilybin at 5 µmol/l. In addition, at 5 and 10 µmol/l, this was the only compound that significantly inhibited HMEC tube formation. Based on an assessment of Akt and ERK1/2 expression, we suggest that 20-O-galloyl-2,3-dehydrosilybin influences the angiogenic process through the Akt pathway.
