The effect of selected plant extracts on the development of single-species dental biofilms.

OBJECTIVE: To determine the effect of a mixture of plant extracts on the adherence and retention of bacteria in dental biofilm. STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Department of Oral Biology, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia, from December 2009 to December 2011. METHODOLOGY: For determination of adhering ability, experimental pellicle was first treated with the Plant Extracts Mixture (PEM) before inoculating it with individual bacterial species (S. mitis / S. sanguinis / S. mutans). For the determination of retention ability, the procedure was repeated with the experimental pellicle being inoculated first with the individual bacterial species and then treating it with the PEM. These two experiments were repeated with deionized distilled water(negative control) and Thymol (0.64%) (positive control). The bacterial populations in biofilms for the two experiments were expressed as Colony Forming Unit (CFU) / mL x 10(4) and the corresponding values were expressed as mean ± SD. RESULTS: The effect of the Plant Extracts Mixture (PEM) for the two experiments was compared with that of Thymol and deionized distilled water. It was shown that there is a reduced adherence of bacteria to PEM-treated and Thymol (0.064%) treated experimental pellicle compared with the negative control (p < 0.001). It was also found that the retention of bacteria in both treated biofilms is also lower than that of negative control (p < 0.001). CONCLUSION: Plant Extracts Mixture (PEM) may influence the development of dental biofilm by affecting the adhering and retention capacities of the bacterial species in the dental biofilms.

Antioxidant and cytoprotective activities of Piper betle, Areca catechu, Uncaria gambir and betel quid with and without calcium hydroxide.

BACKGROUND: Betel quid chewing is a popular habit in Southeast Asia. It is believed that chewing betel quid could reduce stress, strengthen teeth and maintain oral hygiene. The aim of this study was to investigate the antioxidant and cytoprotective activities of each of the ingredients of betel quid and compared with betel quid itself (with and without calcium hydroxide). The correlation of their cytoprotective and antioxidant activities with phenolic content was also determined. METHODS: Five samples (betel leaf, areca nut, gambir, betel quid and betel quid containing calcium hydroxide) were extracted in deionized distilled water for 12 hours at 37°C. Antioxidant activities were evaluated for radical scavenging activity using DPPH assay, ferric reducing activity using FRAP assay and lipid peroxidation inhibition activity using FTC assay. Total phenolic content (TPC) was determined using Folin-Ciocalteu procedure. Phenolic composition was analyzed using LC-MS/MS. Cytoprotective activity towards human gingival fibroblast cells was examined using MTT assay. RESULTS: Among the ingredients of betel quid, gambir demonstrated the highest antioxidant (DPPH - IC50 = 6.4 ± 0.8 µg/mL, FRAP - 5717.8 ± 537.6 µmol Fe(II)/mg), total phenolic content (TPC - 1142.5 ± 106.8 µg TAE/mg) and cytoprotective (100.1 ± 4.6%) activities. Betel quid when compared with betel quid containing calcium hydroxide has higher antioxidant (DPPH - IC50 =59.4 ± 4.4 µg/mL, FRAP - 1022.2 ± 235.7 µmol Fe(II)/mg), total phenolic content (TPC - 140.0 ± 22.3 µg TAE/mg), and cytoprotective (113.5 ± 15.9%) activities. However, all of the five samples showed good lipid peroxidation inhibition compared to vitamin E. LC-MS/MS analysis revealed the presence of quinic acid as the major compound of gambir and betel quid. A positive correlation was observed between TPC and radical scavenging (r = 0.972), reducing power (r = 0.981) and cytoprotective activity (r = 0.682). CONCLUSIONS: The betel quid has higher TPC, and antioxidant and cytoprotective activities than betel quid with calcium hydroxide. The quinic acid in betel quid may play an important role in the oral health protection.

Aberrant proteins in the saliva of patients with oral squamous cell carcinoma.

Confirmation of oral squamous cell cancer (OSCC) currently relies on histological analysis, which does not provide clear indication of cancer development from precancerous lesions. In the present study, whole saliva proteins of patients with OSCC (n = 12) and healthy subjects (n = 12) were separated by 2DE to identify potential candidate biomarkers that are much needed to improve detection of the cancer. The OSCC patients' 2DE saliva protein profiles appeared unique and different from those obtained from the healthy subjects. The patients' saliva α1-antitrypsin (AAT) and haptoglobin (HAP) ß chains were resolved into polypeptide spots with increased microheterogeneity, although these were not apparent in their sera. Their 2DE protein profiles also showed presence of hemopexin and α-1B glycoprotein, which were not detected in the profiles of the control saliva. When subjected to densitometry analysis, significant altered levels of AAT, complement C3, transferrin, transthyretin, and ß chains of fibrinogen and HAP were detected. The increased levels of saliva AAT, HAP, complement C3, hemopexin, and transthyretin in the OSCC patients were validated by ELISA. The strong association of AAT and HAP with OSCC was further supported by immunohistochemical staining of cancer tissues. The differently expressed saliva proteins may be useful complementary biomarkers for the early detection and/or monitoring of OSCC, although this requires validation in clinically representative populations.