Figure 4

Vitamin C formulations influenced the expression in human skin explants, of the mRNA transcripts of (A) genes encoding collagens type I and type III, (B) genes controlling skin fibrils assembly and (C) genes regulating the extracellular matrix (ECM). Fold changes of each transcript were calculated as 2^−ΔCq from Cq normalized by NORMA-gene algorithm⁵⁶, in whole skin explants treated with 1–3 wt% free or formulated Vit C (in donor 1) or with 3–5 wt% free or squalenized Vit C or with squalene (SQ) alone (in donor 2), relative to the untreated control (set to 1, red dotted line). The data from one of two or three analyzed explants are presented (n = 3 per group). Kruskal–Wallis non-parametric test followed by Dunn’s post-test was used to determine significance between the groups (**p < 0.01, *p < 0.05). Graphs were done with GraphPad Prism version 5.0.0 for Windows (GraphPad Software, San Diego, California USA, www.graphpad.com).