A class of cationic, polyphemusin-like peptides having antimicrobial activity is provided. Examples of such peptides include FRWCFRVCYKGRCRYKCR (SEQ ID NO: 3), RRWCFRVCYKGFCRYKCR (SEQ ID NO: 4), and RRWCFRVCYRGRFCYRKCR (SEQ ID NO: 11). Also provided are methods for inhibiting the growth of microbes such as bacteria, yeast and viruses utilizing the peptides of the invention. The peptides are particularly useful for inhibiting endotoxemia in a subject.