Topical and intravaginal microbicidal and antiparasitic compositions comprising quassinoids or quassinoid-containing plant extracts

A method for treating vaginitis caused by Gardenerell vaginalis, the method comprising:

• administering topically or intravaginally to a human or an animal in need of treatment of vaginitis a therapeutically effective amount of a composition consisting essentially of:
• an active agent consisting essentially of at least one quassinoid selected from the group consisting of Brusatol, Ailanthinon, Simalikalactone D, Quassin, 15-desacaetylundulatone, Chaparrinone, 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
• an optional dermo-cosmetically or pharmaceutically topically acceptable excipient.