Abstract: ?-MSH and other amino acid sequences derived from ?-MSH were determined to have antimicrobial influences, including against two major and representative cutaneous and mucosal pathogens; Staphylococcus aureus and Candida albicans, Pharmaceutical compositions useful as antimicrobial agents, including for use in reducing the viability of microbes, reducing the germination of yeasts, killing microbes without reducing the killing of microbes by human neutrophils, for treating inflammation in which there is microbial infection without reducing microbial killing, and for increasing the accumulation of cAMP in microbes are disclosed. The antimicrobial agent is selected from the group consisting of one or more peptides including the amino acid sequence KPV, one or more peptides including the amino acid sequence MEHFRWG, or a biologically functional equivalent of any of the foregoing. The most effective of the peprides were those bearing the C-terminal amino acid sequence of ?-MSH. i.e.

Abstract: The presence of the ancient anti-inflammatory peptide &agr;-melanocyte stimulating hormone (&agr;-MSH [1-13], SYSMEHFRWGKPV) in barrier organs such as gut and skin suggests a role in the nonspecific (innate) host defense system. &agr;-MSH and other amino acid sequences derived from &agr;-MSH were determined to have antimicrobial influences, including against two major and representative cutaneous and mucosal pathogens: Staphylococcus aureus and Candida albicans. &agr;-MSH peptides had antimicrobial effects against S. aureus and significantly reversed the enhancing effect of urokinase on S. aureus colony formation. &agr;-MSH and other amino acid sequences reduced C. albicans viability and germination. &agr;-MSH peptides also enhanced C. albicans killing by human neutrophils.