Effect of flavonoids on antimicrobial activity of microorganisms present in dental plaque.

Dental caries is a multi-factorial oral disease, requiring a susceptible host, cariogenic microorganisms and suitable substrate. Caries is extended worldwide in spite of the availability of countless prophylactic means, including fluoride toothpaste and dental sealers. Many efforts have been made to achieve isolation of pure natural products for medicinal use. Flavonoids are bioactive polyphenol compounds possessing multidimensional effects such as antibacterial action.

The present study targeted the characterization of antibacterial and antifungal activity of various flavonoids (apigenin, catechin, luteolin, morin, myricetin, naringin, quercetin and rutin). Nine strains present in dental plaque were used: Agreggatibacter actinomycetemcomitans, Actinomyces naeslundii, Actinomyces viscosus, Enterococcus faecalis, Escherichia coli, Lactobacillus casei, Staphylococcus aureus, Streptococcus oralis and Streptococcus sanguinis as well as Candida albicans fungal strain.

Results revealed that luteolin, morin, naringin, quercetin and rutin effectively inhibited bacterial and fungal growth. However, morin was the most effective flavonoid.It might then be concluded that flavonoids show bacteriostatic effect on all of tested bacteria and fungus.