Wrinkles are an outward sign of cutaneous aging appearing preferentially on ultraviolet B (UVB)-exposed areas. The anti-wrinkle effects of herbal extracts were investigated in an animal model. Female albino hairless mice (HR/ICR) were randomly allocated to the control group (non-irradiated vehicle), positive control group (UVB irradiated-vehicle), and two herbal extract mixture groups (HE-1 and HE-2). HE-1 included Glycyrrhizae radix, Rhei Rhizoma, Cornus officinalis, and Sesami semeni, and HE-2 included Swertia pseudo-chinensis, Sophora flavescens, Scutellaria baicalensis, and Salvia miltiorrhiza. The herbal extract mixtures were pre-treated dorsally with 0.2 ml per individual five times per week for four weeks prior to the start of UVB irradiation. At the fifth week, the animals were exposed to UVB irradiation for a subsequent eight weeks, three times per week. The intensity of irradiation showed a gradual increase, from 30 mJ/cm 2 to 240 mJ/cm2 (1 MED: 60 mJ/cm2 ). Dorsal skin samples were stained with H&E in order to examine the epidermal thickness. In addition, Masson-Trichrome staining was performed for determination of the amount of collagen fiber. Treatments with HE-1&2 resulted in an increase in the amount of collagen fiber, a better appearance, and fewer wrinkles, compared with the positive control. As determined by hydroxyproline assay, treatments with HE-1&2 led to a significant increase in the amount of collagen, compared with the positive control group (p<0.05). Chronic UVB irradiation to skin of hairless mice resulted in an increase in expression of matrix metalloproteinase-1 (MMP-1), however, treatments with HE-1&2 tended to decrease the expression of MMP-1. These results indicate that the herbal extracts used in this study have a preventive effect on UVB-induced wrinkle formation in a hairless mouse model, due in part to inhibition of MMP-1 expression and increment of collagen amount.

Anti-wrinkle effect of herbal extracts was investigated on the skin of in a model of animal irradiated by ultraviolet rey B (UVB). The female albino hairless mice (HR/ICR) were randomly allocated to the normal control group (NC-non irradiated-vechicle), positive control group (PC, UVB irradiated vehicle) and herbal extract (HE) group. The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunbert, Phellinus linteus, and Phaseolus radiatus. The herbal extract was treated dorsally with 0.2 ml per mouse five times a week for 12 weeks. At fifth week of the treatment, the animals were exposed to UVB irradiation for subsequent eight weeks three times a week. The intensity of irradiation was gradually increased from 30 mJ/㎠ to 240 mJ/㎠ (1MED: 60 mJ/㎠). Dorsal skins were obtained and stained with H&E to examine histological changes and epidermal/dermal thckness. The collagen fiber was also observed in Masson-Trichrome staining. Hydroxyproline assay and western blot analysis were also carried out to detect the change of collagen amount and to investigate MMP-1 expression, respectively. The HE group showed a better appearance and weak wrinkling, compared to PC group, The treatment of herbal extract significantly increased the thickness of dermis and the amount of collagen fibers compared to PC group (p＜0.05). The treatment of HE significantly increased the hydroxyproline amount compared to PC group (p＜0.05). The chronic UVB irradiation to hairless mice skin increased expression of MMP-1 but the treatment of HE decreased the expression of MMP-1. These results indicate that the herbal extract used in this study have a preventive effect on the UVB-induced wrinkle in a hairless mice model, partly due to the reduction of MMP-1 expression and increment of collagen amount.