Screening and Scoring of Antimicrobial and Biological Activities of Italian Vulnerary Plants against Major Oral Pathogenic Bacteria

Abstract

This study aims to evaluate the activity of Italian vulnerary plants against the most important oral pathogenic bacteria. This estimate was accomplished through a fivefold process: (a) a review of ethnobotanical and microbiological data concerning the Italian vulnerary plants; (b) the development of a scoring system to rank the plants; (c) the comparative assessment of microbiological properties; (d) the assessment of potential cytotoxic effects on keratinocyte-like cells and gingival fibroblasts in culture by XTT cell viability assay; (e) clinical evaluation of the most suitable plant extract as antibacterial agent in a home-made mouthwash. The study assays hexane (H), ethanol (E), and water (W) extracts from 72 plants. The agar diffusion method was used to evaluate the activity againstStreptococcus mutans, Streptococcus sobrinus,Lactobacillus casei,andActinomyces viscosus. Twenty-two plants showed appreciable activity. The extracts showing the strongest antibacterial power were those fromCotinus coggygriaScop.,Equisetum hyemaleL.,Helichrysum litoreumGuss,Juniperus communisL., andPhyllitis scolopendrium(L.) Newman subsp.scolopendrium. The potential cytotoxic effect of these extracts was assessed. On the basis of these observations, a mouth-rinse containing the ethanolic extract ofH. litoreumhas been testedin vivo, resulting in reduction of the salivary concentration ofS. mutans.