Fig. 7

Plasma membrane integrity and cell death by apoptosis as induced by a 24 h-exposure of IEC6 cells and HaCaT keratinocytes to 500 μg/mL of specific Rhododendron leaf extracts. Merged micrographs taken with a confocal laser scanning microscope depict IEC6 (a; panels A-E) and HaCaT cells (b; panels F-J). Violet signals in merged images are due to overlapping red, PI-derived signals, in cells with ruptured plasma membranes, and blue, Draq5™ staining of nuclei in all cells. Pictures A and F are control cells treated with 0.5 % DMSO, while cells in all other panels were incubated with extracts from R. cinnabarinum (B and G), R. ferrugineum (C and H), R. minus (D and I) and R. hippophaeoides var. hippophaeoides (E and J). Bars represent 50 μm