The present invention relates to a cosmetic process for caring for human skin, intended to moisturize it and/or to protect it against drying out, comprising the topical application to the skin of a composition containing at least one active agent that stimulates the expression of the matriptase MT/SP1. It also relates to the cosmetic use of such an active agent for moisturizing human skin and/or protecting it against drying out. It further relates to the use of such an active agent to manufacture a pharmaceutical composition intended to prevent and/or alleviate skin tautness, stinging and/or itching and/or lip chapping. The active agents are extracts of Ceratonia siliqua, Cananga odorata hook, Cedrelopsis grevei and Cistus ladaniferus L.