FIGURE 1.

Capsaicin alleviates the UV-induced reduction of collagen in mouse skin in vivo. Female C57BL/6 mice, 8 weeks old, were shaved at dorsal skin and divided into four groups: Control (vehicle only); UVB (exposed to UVB irradiation at 300 mW/m² for 30 min each day); UVB + Cap (pre-treated with capsaicin at 5 μM and exposed to UVB irradiation at 300 mW/m² for 30 min each day); Cap (treated with capsaicin at 5 μM each day). (A) Mice were sacrificed, and the photos of dorsal skin were taken. (B) The 10-μm skin section was stained with H&E staining to show the nucleic acid (purple), cytoplasm and extracellular matrix (red). (C) IHC staining was performed to show the expression and localization of COL1 (collagen type I; brown) and nucleic acid (blue) in skin. Dotted line marked the epidermis and dermis layers. (D) The protein lysates of dorsal skin were collected for ELISA assay to measure COL1 content. Values are in percentage of change against control, in mean ± SD, n = 5, each with triplicate samples. *, p < 0.05; **, p < 0.01 compared with control (vehicle only).