Periodontal diseases and dental caries are common oral disorders in human population with a multifactorial etiology closely related with the development of dental plaque. The latter is composed of native oral microbiota and it is accumulated on teeth surfaces. Several antiseptic agents are used widely to inhibit bacterial growth [1,2]. However, these substances have adverse effects. In the current study, Melissa officinalis L. and Crocus sativus L. extracts were tested as potential natural antimicrobial agents. The antimicrobial activity of plants extracts was studied towards Gram-positive strains belonging to Streptococcus species related to the oral health. Fourier transform infrared spectroscopy (FT-IR) was applied in order to evaluate the changes in the cellular composition of target bacterial cells after their exposure to extracts of both plants.
