Inhibitory Effects of Nude Pack Containing Black Tea Water Extract on Skin Wrinkle Formation in Hairless Mice

ABSTRACT The aim of this study was to evaluate the inhibitory effect of nude pack containing black tea water extract (NPBT) onskin wrinkle formation in hairless mice. Skin wrinkles were induced by UVB irradiation to the backs of hairless mice for5 weeks. And at the same time, NPBT was applied topically. Wrinkle formation, histological changes, expression ofmatrix metalloproteinase-3 (MMP-3) and protein activities of MMP-2 and MMP-9 were observed or analyzed. Wrinklesfor the control group were formed as a pattern of deep furrows and thick crests. Whereas wrinkles for the NPBT treatedgroup were formed as a pattern of shallow furrows and thin crests, and their wrinkle areas were significantly(p⁄0.001)lower than the control group. Collagen fibers were arranged irregularly and sparse in density and some elastic fibers weredegenerated in the control group, while they were almost intact in the NPBT treated group. MMP-3 mRNA expression inthe control group was significantly(p⁄0.001) higher than the normal group, and that of NPBT treated group was signifi-cantly (p⁄0.001) lower than the control group. The NPBT treated group showed remarkably lower protein activities ofMMP-2 and MMP-9 than the control group. NPBT could have a considerable inhibitory effect on skin wrinkle formationin hairless mice.Keywords : Black tea extract, Collagen fiber, Hairless mice, MMP, Wrinkles