Abstract: To increase a tissue regeneration ability of a living body such as a collagens production ability of fibroblast in the dermis in a skin defect area typified by a large wrinkle or wound, a flavanone derivative such as farrerol is used as an active ingredient of an external preparation for skin. Further, to efficiently screen a substance having an excellent effect on promoting wound healing, the remodeling action of collagen fiber bundle is tested by using skin wound model.

Abstract: It is intended to provide a method whereby the skin conditions (for example, loss in the skin elasticity, wrinkle formation possibility, insufficient tightness in dermal collagen fiber bundles, or the like) can be exactly and conveniently assessed. It is also intended to provide a method whereby the wrinkle-improvement effect of a test substance can be exactly and conveniently evaluated. The skin conditions are assessed by using the expression amount of an adhesion factor in skin cells as an indication. The wrinkle reducing effect of a test substance is evaluated by using the expression amount of an adhesion factor in skin cells in the presence of the test substance as an indication.

Abstract: To increase a tissue regeneration ability of a living body such as a collagens production ability of fibroblast in the dermis in a skin defect area typified by a large wrinkle or wound, a flavanone derivative such as farrerol is used as an active ingredient of an external preparation for skin. Further, to efficiently screen a substance having an excellent effect on promoting wound healing, the remodeling action of collagen fiber bundle is tested by using skin wound model.