Figure 4.

Effect of corn silk (CS) extract on collagen fiber content in UVB-photoaged mouse skin. Collagen fibers were stained with Masson’s trichrome (MT) (A) and Verhoeffe Van Gieson (VVG) (B). Representative histological images of collagen in mouse skin tissue are presented at an original magnification of ×200. Collagen staining by MT and VVG appears blue and red, respectively. Staining density of MT (C) and VVG (D) are shown, respectively. Western blotting detected MMP-9 (E), TIMP-1 (F), TGF-β (G), p-SMAD2/SMAD2 (H), and α-tubulin expression levels in the UVB-irradiated dorsal skin protein extract of hairless mouse by using specific antibodies for each protein. Blot image is a representation of three individual experiments. The blots were quantified using ImageJ software and the signal intensities were normalized to the value of α-tubulin, except for p-SMAD2, which was normalized to the expression of SMAD2. The mRNA expression of procollagen type 1 was assessed by q-PCR analysis and was normalized to the intensity value of GAPDH, quantified using ImageJ (I). Values are mean ± SE. Mean values not assigned with the same letter (a, b, c, d) are significantly different, analyzed by ANOVA (p < 0.05). Group abbreviations: Normal group (NOR), UVB-irradiated group (UVB), UVB-irradiated and low (2 g/kg/day) CS-treated group (CSL), UVB-irradiated and high (4 g/kg/day) CS-treated group (CSH).