Antimicrobial activity of indigowoad (Isatis indigotica fort) and plains wild indigo (Baptisia bracteata) roots

Abstract

Indigowoad Roots (IR) (Isatis indigotica Fort) and Plains Wild Indigo Roots (PWIR) (Baptisia bracteata) have been shown to be high in phenolic compounds and plants high in phenolic compounds often have beneficial health effects including antimicrobial activity. Indigowoad is a well-known medicinal plant as well as an edible plant root similar to daikon, sweet potatoes, yam, ginseng and carrots. Plains wild indigo roots, leaves and seeds have traditionally been used by native Americans for medicinal purposes and its extracts are consumed to enhance health. The in vitro antimicrobial activity of IR and PWIR was determined on five microbes (Escherichia coii, Pseudomonas aeruginosa, Legionella pneumophila sub sp., Pneumophila, Staphylococcus aureus and Streptococcus mutant, as well as general oral cavity bacteria. The IR2 inhibited cell growth of 5. aureus, £ coli, S. mutans and P. aeruginosa. The PWIR inhibited cell growth of S. aureus and P. aeruginosa, which are normal skin flora, E. coll is a normal intestinal parasite and S. mutansis causes tooth decay and periodontal disease. The best treatment for oral cavity bacteria was IR2 which reduced bacterial counts by 2.63±0.26 log relative to water treatment. The PWIR reduced them by 0.66±0.21 log.