Inhibitory effect of some herbal extracts on adherence of Streptococcus mutans

The objective of this study was to investigate the inhibitory effect of the crude extracts from some herbs on adherence of Streptococcus mutans (S. mutans) ATCC 25175 and TPF-1 in vitro. Six herbs, Andrographis paniculata; Cassia alata; Chinese black tea (Camellia sinensis); guava (Psidium guajava); Harrisonia perforata and Streblus asper, were extracted with 50 or 95% ethanol and dried. Herbal extracted solution at 0.5% concentration (w/v) was initially tested for bacterial adherence on glass surfaces. In order to identify type and effective concentration of the extracts, the extracts that showed the inhibition on glass surfaces were then tested on saliva-coated hydroxyapatite by the use of radiolabeled bacteria. To study the mechanism of action, the effect of the extracts at such concentration on glucosyltransferase and glucan-binding lectin activities were examined. It was found that all extracts, but Streblus asper, showed significant inhibitory effect on bacterial adherence to glass surfaces. For the saliva-coated hydroxyapatite adherence assay, Andrographis paniculata, Cassia alata, Chinese black tea and Harrisonia perforata could inhibit adherence of S. mutans ATCC 25175. Chinese black tea was the strongest inhibitor followed by Andrographis paniculata, Cassia alata and Harrisonia perforata, respectively. For S. mutans TPF-1, adherence inhibition was observed from Andrographis paniculata and Cassia alata at similar levels. The lowest concentrations of the extracts that inhibited the adherence at least 50% were 0.5% of Andrographis paniculata, 0.5% of Cassia alata, 0.3% of Chinese black tea and 0.5% of Harrisonia perforata for S. mutans ATCC 25175. For S. mutans TPF-1, the effective concentrations were 0.5% of Andrographis paniculata and 0.4% of Cassia alata. All extracts at such concentrations decreased the activity of glucosyltransferase from both strains. Only Andrographis paniculata and Cassia alata eliminated or decreased the activity of glucan-binding lectin from both strains. These findings suggested that Andrographis paniculata, Cassia alata, Chinese black tea and Harrisonia perforata could inhibit adherence of S. mutans ATCC 25175, while Andrographis paniculata and Cassia alata had an effect on S. mutans TPF-1 in vitro at the concentrations employed in this study.     

The effect of topical metronidazole therapy on experimentally-induced periodontitis in the beagle dog

Abstract. The present study was performed to assess the effect of topical metronidazole therapy on ligature-induced periodontitis in beagle dogs. 6 beagle dogs with experimentally-induced periodontitis on the mandibular 2nd, 3rd and 4th premolars were treated with metronidazole 10% dental paste 2 × daily for 4 weeks in an open placebo-controlled study using a split-mouth design. Recordings of probing pocket depth, bleeding on probing and gingival index were performed before commencement of treatment and repeated weekly during the 4-weeks treatment period. Concurrently, samples for microbiological analysis were collected from 2 of the dogs. The results demonstrated that probing pocket depth, bleeding on probing and gingival index had improved significantly in the metronidazoletreated side compared with the placebo-treated side. Black pigmented Bacteroides spp. and Spirochetes, present in all samples before treatment, were eliminated from the metronidazole-treated side after the 1st week of treatment and throughout the treatment period, whereas they were present in all samples from the placebo-treated side. The result of the present study demonstrates that topical application of metronidazole in a dental paste, improves the clinical features of the experimentally-induced periodontitis and eliminates some of the micro-organisms associated with the disease.     

Candida in oral lichen planus patients undergoing topical steroid therapy.

OBJECTIVES: To determine the incidence, intensity, and species of Candida in the oral cavity of oral lichen planus (OLP) patients who were being treated with a topical steroid. STUDY DESIGN: The incidence and intensity of oral Candida carriage were assessed by salivary and imprint cultures. Cytological smears were used to investigate the presence of Candida spores and hyphae in the OLP lesions. Candida species were identified by a chlamydospore formation test and the API 20C system. RESULTS: The salivary cultures were positive in 76.7% of the OLP patients and 43.3% of the controls (P = .008), whereas the imprint cultures were positive in 76.7% of the OLP patients and 40% of the controls (P = .004). A high-level Candida count in saliva was more frequently found in the OLP patients than in the controls (73.9% vs. 38.5%; P = .004). The mean scores of Candida growth from imprint cultures were higher in OLP patients than in the controls (P = .002). The mean scores of Candida growth were also higher in OLP patients who were taking xerogenic or immunosuppressive drugs (P = .038) and in OLP denture wearers (P = .022). Spores and hyphae were detected in 83.3% of the OLP lesions. Candida albicans, the most frequently isolated yeast, was found in 76.7% OLP patients and 40% of the controls. CONCLUSIONS: The results of this study indicate that topical steroids induce Candida growth and the associated risk factors are age, medication use, and the wearing of dentures.