Determination of the in vitro and in vivo antimicrobial activity on salivary Streptococci and Lactobacilli and chemical characterisation of the phenolic content of a Plantago lanceolata infusion.

Introduction. Plant extracts may be suitable alternative treatments for caries. Aims. To investigate the in vitro and in vivo antimicrobial effects of Plantago lanceolata herbal tea (from flowers and leaves) on cariogenic bacteria and to identify the major constituents of P. lanceolata plant. Materials and Methods. The MIC and MBC against cariogenic bacteria were determined for P. lanceolata tea. Subsequently, a controlled random clinical study was conducted. Group A was instructed to rinse with a P. lanceolata mouth rinse, and Group B received a placebo mouth rinse for seven days. The salivary colonisation by streptococci and lactobacilli was investigated prior to treatment and on the fourth and seventh days. Finally, the P. lanceolata tea was analysed for its polyphenolic content, and major phenolics were identified. Results and Discussion. P. lanceolata teas demonstrate good in vitro antimicrobial activity. The in vivo test showed that Group A subjects presented a significant decrease in streptococci compared to Group B. The phytochemical analysis revealed that flavonoids, coumarins, lipids, cinnamic acids, lignans, and phenolic compounds are present in P. lanceolata infusions. Conclusions. P. lanceolata extract could represent a natural anticariogenic agent via an antimicrobial effect and might be useful as an ancillary measure to control the proliferation of cariogenic flora.

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

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 against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, and Actinomyces viscosus. Twenty-two plants showed appreciable activity. The extracts showing the strongest antibacterial power were those from Cotinus coggygria Scop., Equisetum hyemale L., Helichrysum litoreum Guss, Juniperus communis L., and Phyllitis 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 of H. litoreum has been tested in vivo, resulting in reduction of the salivary concentration of S. mutans.

Antimicrobial properties of green tea extract against cariogenic microflora: an in vivo study.

The aim of the present study was to test in vivo the effectiveness of an experimental green tea extract in reducing levels of mutans streptococci and lactobacilli in saliva by means of selective culture medium. Sixty-six healthy patients ranging in age from 12 to 18 years were recruited and randomly divided into two groups: Group A (n=33) and group B (n=33). Group A subjects were asked to rinse their mouths with 40 mL of an experimental green tea extract, for 1 minute, three times a day for a week, whereas Group B subjects were asked to rinse with 40 mL of a placebo mouth rinse. Saliva samples were obtained at baseline, 4 days, and 7 days. The counts of mutans streptococci and lactobacilli were investigated by chair-side kits. Data were statistically processed. A regression binary logistic analysis was done. The statistical significance level was established at P<.05. The experimental group showed a statistically significant reduction in colony counts of mutans streptococci and lactobacilli relative to the control group. These findings showed the efficacy of a green tea extract against cariogenic oral flora, opening a promising avenue of clinical applications in the preparation of specific and natural anticariogenic remedies.