Microbicidal and antiparasitic compositions

A method for treating a condition caused by a parasitic or anaerobic bacterial infection of skin or mucosa, the method comprising:

• administering to a skin or mucus infected by a parasite or an anaerobic bacteria of a human or an animal a therapeutically effective amount of a composition consisting essentially of:
• a. an active agent consisting essentially of at least one quassinoid selected from the group consisting of Brusatol, Ailanthinon, Simalikalactone D, Quassin, Chaparrinone, 15-desacaetylundulatone, 15β-heptylchaparrinone, Neoquassin, Isoquassin, Parain, Quassimarin, Quassinol, Quassol, 18-hydroxy-quassin, Ailantinol A, Ailantinol B, Ailantinol C, Ailantinol D, Ailantinol E, Ailantinol F, Ailantinol G, Bruceanol A, Bruceanol B, Bruceanol C, Bruceanol D, Bruceanol E, Bruceanol F, Bruceanol G, Bruceanol H, Picrasinol A, Picrasinol B, Picrasinol C, Picrasinol D, Bruceoside A, Bruceoside B, Bruceoside C, Picrasinoside A, Picrasinoside B, Picrasinoside C, Picrasinoside D, Picrasinoside E, Picrasinoside F, Picrasinoside G, Picrasinoside H, Eurycomanone, 2-acetylglaucarubine, 13,18-dehydroglaucarubine, Glaucarubinone, Glaucarubine, Holacanthone, 20-simarolide, Simarubolide, Dehydroquassin, Isoparain, Nigakilactone A, Norneoquassin, and Quassialactol;
• and
• b. an optional dermo-cosmetically or pharmaceutically topically acceptable excipient.