Fig. 6

Effect of F3 fraction of G. tinctoria extract and crude extract on nitric oxide levels. Nitric oxide (NO) levels were determined with DAF through fluorescence microscopy in HUVECs incubated (37 °C, 24 h) with M199 in absence (Control) (c) or presence of 200 μg/L of G. tinctoria extract (labeled as G. tinctoria) (a), 200 μg/L of ellagic acid-enriched fraction (labeled as F3) (b) or vehicle (d). Positive control were cells incubated (37 °C, 5 min) with 10 μM histamine (labeled histamine) (e). In images, green fluorescence corresponds to DAF probe and blue fluorescence corresponds to 4′,6-diamidino-2-phenylindole, for nuclei staining. The density of DAF fluorescence per cell was quantify using ImageJ software and was expressed as rate of control (f). Values were expressed as mean ± SE, n = 3. *p < 0.05 versus Control; ^Фp < 0.05 versus vehicle. The scale bar represents 50 μm