Cosmetic or pharmaceutical composition comprises at least a polypeptide derived from aconitase enzyme or its derivative, comprising 3-50 amino acid residues, preferably 3-8 amino acid residues, as active ingredient in a medium. Cosmetic or pharmaceutical composition comprises at least a polypeptide derived from aconitase enzyme or its derivative, comprising 3-50 amino acid residues, preferably 3-8 amino acid residues, and of which the sequence is of formula (R 1-(AA) n-X 1-X 2-X 3-(AA) p-R 2) (I), as active ingredient in a medium. X 1threonine, leucine or isoleucine； X 2glutamine, asparagine or any amino acid； X 3threonine, serine or any amino acid； AA : any amino acid or its derivatives or absence of aconitase sequence； R 1primary amine function of N-terminal amino acid, free or substituted by a protective group optionally selected from a acetyl, benzoyl, tosyl or benzyloxycarbonyl group； R 2hydroxyl group of carboxy function of the C-terminal amino acid, free or substituted by a protective group optionally 1-20C alkyl, NH 2, NHY 1or NY 1Y 1； Y 11-4C alkyl chain； and n, p : 0-4. ACTIVITY : Dermatological； Cardiant； Muscular-Gen； Neuroprotective； Antidiabetic； Nootropic. MECHANISM OF ACTION : None given.
