Fig. 4
Effect of RTA 408 Lotion on the Protein Expression of NQO1 in Human Skin Biopsies from Phase 1 Clinical Trial. Skin biopsies were collected from healthy volunteers one day after the final dose in Parts a, b, and c of the Phase 1 clinical trial. Part a evaluated 3 concentrations of RTA 408 Lotion (0.5, 1, and 3 %) compared to lotion vehicle applied topically to 12 healthy subjects BID for 14 days to a small skin surface area on the lower back (4 cm2 for each concentration). Part b was open-label and assessed the RTA 408 Lotion (3 %) applied topically to 10 healthy subjects BID for 14 days to skin on the lower back (100 cm2). Part c was open-label and assessed the RTA 408 Lotion (3 %) applied topically to 10 healthy subjects BID for 28 days to skin on the lower back (500 cm2). Representative photomicrographs (20X) from each part are presented on the left with corresponding quantified staining intensities presented on the right. Dots represent individual data points for each subject. Bars present data as mean fold vehicle or untreated control ± S.E.M. *p < 0.05 vs. vehicle or untreated control