Figure 6.

Honey extracts modulate the UVB-induced mRNA expression of MMPs in a 3D reconstituted human skin model (Epiderm^TM EPI-200). Tissues were pre-treated with 20 μg/mL of honey extracts ME16.1 (a) or ME20.3 (b) for 2 h, UVB irradiated (55 mJ/cm²) and then treated with honey extracts for 2 h. After 24 h, the tissues were harvested and total RNA was extracted. For the quantification of MMPs-1, -3, -7 and -9 mRNA levels quantitative real-time PCR was performed. The expression levels of all MMPs were normalized to those of β-actin. Untreated cells served as reference sample. For the relative quantification, the formula RQ = 2^−ΔΔCt was used. Representative graphs of three independent experiments. Each reaction was performed in triplicate. ** p ≤ 0.01, *** p ≤ 0.001, significant differences compared to the UVB-irradiated cells.