Non-therapeutic cosmetic use of at least one compound capable of modulating the interaction between a first and a second associated protein, homologues, or fragments of said proteins, said first and said second protein being the Skin Aspartic Protease, or SASPase, and phylagrin -2, or FLG2, as an active agent to treat and / or prevent an aesthetic defect of the skin and / or its annexes associated with an imbalance of differentiation and / or proliferation of the cells of an epidermis, said compound being represented by the following general formulas (Ia) or (Ib): ** Formula ** in which: - R1 represents H, a C1-C4 alkyl, linear or branched, saturated or unsaturated, or -C (O) R8 , in which R8 represents a C1-C4 alkyl, linear or branched, saturated or unsaturated, where R1 preferably represents H, a methyl, an ethyl, a propyl, or -C (O) R8 in which R8 represents a methyl , an ethyl or a propyl； - R2 represents>； = O, -OR9 or -OC (O) R9, in which R9 represents H or a C1-C2 saturated alkyl, where R2 preferably represents>； = O or -OR9, preferably>； = O； - R3, R4, R5, R6, R7 represent, independently of each other, H； -NO2； -OH； a fluorine； -CF3； a C1-C4 alkyl, linear or branched, saturated or unsaturated； a phenyl； -OC (O) -CH (Ph) 2； -O-Ph-X where X represents H, -OH, -NO2, a fluorine, an alkyl or a C1-C4 alkoxy, linear or branched, saturated or unsaturated； -O-S (O2) -Ph-Z where Z represents a C1-C4 alkyl, linear or branched, saturated or unsaturated； -R8OH； -OR9； -OC (O) R9 where R8 and R9 are as previously defined； -R10Ph where R10 is a C1-C4 alkylene, linear or branched, saturated or unsaturated； or -OC (O) -Yn-Ar1- (X) m where - n represents 0 or 1 and m represents an integer that varies from 0 to 4, provided that n and m do not simultaneously represent 0, where Y represents an alkylene in C1-C4 , linear or branched, saturated or unsaturated, X is as previously defined, and Ar1 represents ** Formula ** where * represents a union with Y and @ represents a uni
