(i). Rabbit skin epidermis ATR-FTIR: (a) untreated, (b) treated with F1, (c) treated with F5, (d) treated with F9, (ii). Representation of rabbit skin dermis FTIR: (e) untreated, (f) treated with F1, (g) treated with F5, (h) treated with F9, data are expressed as mean ± SD; n = 3.