Magainins are peptide antibiotics with antibacterial and antiparasitic activities, originally extracted from the skin of Xenopus laevis. Magainin 1 and 2 are closely related peptides of 23 amino acids each and differ by two substitutions. These antimicrobial peptides have broad-spectrum, non-specific activity against a wide range of micro-organisms, including viruses, gram-positive and gram-negative bacteria, protozoa, yeasts and fungi, and may also be hemolytic and cytotoxic to cancer cells. Magainin 1 is a bactericide. Both Magainin 1 and 2 exhibit inhibitory action toward Herpes simplex virus type 1(HSV-1) and HSV-2.