In vivo effects of DPTTS on skin fibrosis in HOCl mice ( n = 8 mice per group). (a) Dermal thickness as measured in the injected area. (b) Collagen content in the skin as measured by the Sircol method. (c) Representative tissue sections of dermal fibrosis (H&E staining), α-SMA, and pSmad 2/3 expressions (immunohistochemistry) in the injected areas. Magnification is × 50 (Olympus DP70 Controller). (d) Proliferation of fibroblasts from normal and HOCl mice treated or not with DPTTS. Cellular proliferation (cpm) was measured by thymidine incorporation. Values are expressed as mean ± SEM of data gained from all mice in the experimental or control groups. *P < 0.05; **P < 0.01; ***P < 0.001.