Topical Administration of Manuka Oil Prevents UV-B Irradiation-Induced Cutaneous Photoaging in Mice
Manuka oil inhibits UV-B-induced reduction of collagen fiber content and expression of MMPs. (a) Representative images of collagen fibers (blue color) stained by Masson-trichrome staining protocol in the skin biopsy obtained at the end of the experiment from the no UV-B irradiation control group (no UV-B), vehicle only group (vehicle), and the group that received 10% manuka oil (manuka oil), respectively. Magnification: 200x fold; scale bar: 200 μm. (b) Relative % collagen density from each image was estimated by using Image Pro Plus 6.0 software.24 and normalizing to the density of normal skin control (100%). The values are mean ± SEM ( per each group). ##: significantly different from noUV-B control group (). **: significantly different from vehicle only group (). (c) m-RNA levels of MMP-1 and MMP-3 in the skin tissue for each group were estimated using RT-PCR of total RNA isolated from the pooled biopsies of each group obtained at the end of the experiment. Et-Br stained bands are shown afterphotopicture. RT-PCR of GAPDH m-RNA was used for an internal control.