Studies on the antimicrobial activity of juglans regia

Juglans regia L. bark is used in some countries as a toothbrush and as a dye for coloring the lips for cosmetic purposes. Its extract showed a broad spectrum antimicrobial activity in a dose dependent manner. It inhibited the growth of several species of pathogenic micro-organisms representing Gram-positive bacteria (Staphylococcus aureus and Streptococcus mutans), Gram-negative bacteria (Esherichia coli and Pseudomonas aeruginosa) and a pathogenic yeast (Candida albicans). The extract has either synergistic or additive action when tested with a wide range of antibacterial drugs. It also increased the pH of saliva. Thus, brushing the teeth with this bark may improve oral hygiene, prevent plaque and caries formation, and reduce the incidence of gingival and periodontal infections.