Applicability of Licorice Extracts for Treatment of Oral Diseases, Evaluated by Simplified In Vitro Assay Systems with Oral Cells

Licorice extracts contain various useful substances for oral health. Alkaline extract showed potent anti‐HIV activity, whereas flavonoid‐rich water extracts showed potent anti‐HSV activity, closely correlated with polarizability, ionization potential, a number of ring systems, atomic number and mass. Licorice flavonoids showed higher tumor‐specificity against human oral squamous cell carcinoma as compared with human normal oral mesenchymal cells. Glycyrrhiza, at noncytotoxic concentrations, potently inhibited the IL‐1β‐induced inflammation in cultured human gingival and periodontal ligament fibroblasts. Glycyrrhizin, a major component of Glycyrrhiza, showed the highest UV‐protected activity. The results suggest the possible applicability of licorice extracts for several oral diseases and cosmetic products

Antimicrobial Susceptibilities of Oral Isolates of <i>Abiotrophia</i> and <i>Granulicatella</i> According to the Consensus Guidelines for Fastidious Bacteria

Background: The genera Abiotrophia and Granulicatella, previously known as nutritionally variant streptococci (NVS), are fastidious bacteria requiring vitamin B6 analogs for growth. They are members of human normal oral microbiota, and are supposed to be one of the important pathogens for so-called &#8220;culture-negative&#8222; endocarditis. Methods: The type strains and oral isolates identified, by using both phenotypic profiles and the DNA&#8315;DNA hybridization method, were examined for susceptibilities to 15 antimicrobial agents including penicillin (benzylpenicillin, ampicillin, amoxicillin, and piperacillin), cephem (cefazolin, ceftazidime, ceftriaxone, and cefaclor), carbapenem (imipenem), aminoglycoside (gentamicin), macrolide (erythromycin), quinolone (ciprofloxacin), tetracycline (minocycline), glycopeptide (vancomycin), and trimethoprim-sulfamethoxazole complex. The minimum inhibitory concentration and susceptibility criterion were determined, according to the consensus guideline from the Clinical and Laboratory Standards Institute. Results: Isolates of Abiotrophia defectiva were susceptible to ampicillin, amoxicillin ceftriaxone, cefaclor, imipenem, ciprofloxacin, and vancomycin. Isolates of Granulicatella adiacens were mostly susceptible to benzylpenicillin, ampicillin, amoxicillin, cefazolin, ceftriaxone, imipenem, minocycline, and vancomycin. The susceptibility profile of Granulicatella elegans was similar to that of G. adiacens, and the susceptibility rate was higher than that of G. adiacens. Conclusions: Although Abiotrophia and Granulicatella strains are hardly distinguishable by their phenotypic characteristics, their susceptibility profiles to the antimicrobial agents were different among the species. Species-related differences in susceptibility of antibiotics should be considered in the clinical treatment for NVS related infections