Melanocyte-stimulating hormone inhibitor and external preparation containing the same

A topical composition to inhibit melanocyte-stimulating hormone comprising an effective amount of a peptide of the following formula [I], [II], or [III] to inhibit melanocyte stimulating hormone:

• -His-Ser-Arg-Trp- [I]
• -Trp-Arg-Ser-His [II]
• -Leu-Ala-Cys-Ala-Arg- [III]
• wherein His, Ser, Arg, Trp, Leu, Ala and Cys represent L- or D-histidine, serine, arginine, tryptophan, leucine, alanine and cysteine residues, respectively, and an inert carrier.

A topical composition to inhibit melanocyte-stimulating hormone comprising an effective amount of an amino acid sequence represented by the following general formula (IV), (V) or (VI) to inhibit melanocyte stimulating hormone:

• X-His-Ser-Arg-Trp-Y (IV)
• P-Trp-Arg-Ser-His-Q (V)
• X.sub.1 -Leu-Ala-Cys-Ala-Arg-Y (VI)
• wherein His, Ser, Arg, Trp, Leu, Ala and Cys represent L- or D-histidine, serine, arginine, tryptophan, leucine, alanine and histidine, serine, arginine, tryptophan, leucine, alanine and cysteine residues, respectively, X and P each represent a hydrogen, an acyl group having 1 to 12 carbon atoms, an amino acid residue, or acylated derivative thereof having 1 to 12 carbon atoms, peptide residue having 2 to 40 amino acid residues or acylated derivative thereof, and Y and Q each represent a hydroxyl group, an amino group, an amino acid residue, or amidated derivative thereof, and or a peptide residue having 2 to 40 amino acid residues or amidated derivative thereof, and X.sub.1 represents a hydrogen, an acyl group having 1 to 12 carbon atoms, an amino acid residue, or acylated derivative thereof having 1 to 12 carbon atoms, or a peptide residue having 2 to 40 amino acid residues or acylated derivative thereof, and Y.sub.1, represents a hydroxyl group, an amino group, an amino acid residue, or amidated derivative thereof, or a peptide residue having 2 to 36 amino acid residue or amidated derivative thereof, wherein the peptide of the formula (IV) or (V) has a molecular weight in the range of 584 to 10,000 and the peptide of the formula (VI) has a molecular weight in the range of 532 to 10,000, and an inert carrier.