New approach to suppressing wrinkles

Skin-thinning in aged skin is considered an important factor in the formation of wrinkles. Due to natural ageing of the epidermal keratinocytes, there is a remarkable production of senescenceassociated secretory phenotype (SASP) factor, which induces matrix metalloproteinase-1 production in dermal fibroblasts, resulting in dermal thinning. Meanwhile, extracellular ATP (eATP) is known to induce the production of SASP factors, but the relationship between eATP and natural ageing is unknown. In this study, we showed the relationship between the increase of eATP in the epidermis and the dermal thinning seen with natural ageing. Peppermint leaf extract (PME) effectively suppressed the rise in eATP concentration due to natural ageing and environmental stress. Furthermore, PME suppressed skin thinning and improved various wrinkles, such as crow’s feet and neck wrinkles. These results suggest that PME is an antiageing material that suppresses eATPmediated dermal thinning and effectively improves wrinkles in many areas.

The formation of wrinkles is a typical ageing phenomenon that is characterised by the acceleration of the decomposition of the extracellular matrix (ECM) in the dermis. In general, wrinkles are formed because of natural ageing, dryness, UV-rays, etc.1,2 As natural ageing and photo-ageing are accompanied by the deformation of collagen and elastic fibres in the dermis, it is believed that wrinkles are formed by the hardening and decrease in number of these fibres.2,3

It is known that the decomposition of ECM components in the dermis is caused by the protein degradation action of matrix metalloproteinases (MMPs), especially MMP-1. The production of MMPs has been reported to be increased by factors secreted from keratinocytes called senescenceassociated secretory phenotypes (SASP).4