The peptides have the general following formula: X-Pro*-Pro*-Xaa-Y in which: —Xaa is selected from
Leucine (Leu, L),
Arginine (Arg, R),
Lysine (Lys, K),
Alanine (Ala, A),
Serine (Ser, S), and
Aspartic acid (Asp, D); —At the N terminal end of the
peptide, X is selected from H, —CO—R1 and —SO2—R1; —At the C terminal end of the
peptide, Y is selected from OH, OR1, NH2, NHR1 and NR1R2; —R1 and R2 are, independently from each other, selected from an alkyle, aryle, aralkyle, alkylaryl, alkoxy and aryloxy group, that can be linear, branched, cyclic, poly-cyclic, non-saturated, hydroxylated, carbonylated, phosphorylated and / or sulfured, and which skeletum can comprise an
heteroatom, in particular an O, S and / or N atom;—Pro* correspond to a
Proline, an analogue or derivative thereof; —if X is H then Y is selected from OR1, NH2, NHR1 and NR1R2, and if Y is OH then X is —CO— or —SO2—R1; and the
peptide hypoxanthine-Pro-Pro-Arg being excluded. The invention provides the use of the peptides of above formula I to stimulate the synthesis of the molecules constituting the dermal
extracellular matrix, including
collagen I and IV and
elastin. A cosmetic treatment according to the invention includes anti-aging, anti-wrinkles, improving mechanical properties of the
skin, firmness / tone / elasticity / suppleness / flexibility, increasing density and volume of the
skin, restructuring effect, fighting
stretch marks, improving
skin barrier and / or
skin hydration.