FIGURE 4.

The primary human fibroblasts viability determined using PrestoBlue assay (A) and LDH assay (B) after 24 h of treatment with: 0.01, 0.1, 0.2, 0.5, 1.0, 2.5, and 5.0% of the tested hydrogels corresponding to 5, 50, 100, 250, 500, 1250, and 2,500 μg/ml of E. angustifolium extracts. The results are expressed as the mean and SD from three independent experiments; a = p < 0.05 vs. H-CON; b = p < 0.05 vs. ctrl; c = p < 0.05 vs. HEa-WA. Optical microscopy images of primary human fibroblasts after 24 h incubation with the standard medium (negative control), 5.0% of hydrogel without HEas (as vehicle control, H-CON), Lysis Solution (positive control in LDH assay) and 0.01, 0.1, 0.2, 0.5, 1.0, 2.5, and 5.0% of the tested hydrogels (HEa-WA, HEa-EtOH and HEa-iPrOH) corresponding to 5, 50, 100, 250, 500, 1250, and 2,500 μg/ml of E. angustifolium extracts. Cells with the medium were used as a negative control, and cells treated with the hydrogel (5%) without HEas were used as a vehicle control (H-CON) (C).