Antimicrobial activity of medicinal plants from South America.

Native people of America have a vast heritage in the knowledge and use of medicinal plants (MPs) that continue to surprise the scientific community. MPs are defined as vegetables that are useful in therapeutics because they possess active compounds. The geographic situation of South America allows the development of one of the most variable and rich medicinal floras. Botanical names, popular use and parts utilized of MPs are well documented in folk medicinal practice in South America. In this work several scientific studies are described that use different fractions obtained from vegetables. Useful antimicrobial phytochemicals can be divided into several categories: phenols and phenolic acids, quinones, flavones and flavonoids, tannins, coumarins, essential oils (EOs), alkaloids, lectins and polypeptides. These studies confirm that many EOs and plant extracts possess antibacterial activity (ABA), antifungal activity (AFA) and antiviral activity (AVA) in vitro. The scientific investigations of antimicrobial activity (AA) of plant products showed a good correlation with the reported traditional medicinal use. The preservation of species in the native flora appears to be crucial for the maintenance of biodiversity. There is a need to preserve the vegetable populations in their natural habitats.