Khan Shams Tabrez, Khan Merajuddin, Ahmad Javed, Wahab Rizwan, Abd-Elkader Omar H, Musarrat Javed, Alkhathlan Hamad Z, Al-Kedhairy Abdulaziz A
Zoology Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
DNA Research Chair, Zoology Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
AMB Express. 2017 Dec;7(1):49. doi: 10.1186/s13568-017-0344-y. Epub 2017 Feb 23.
Organic compounds from plants are an attractive alternative to conventional antimicrobial agents. Therefore, two compounds namely M-1 and M-2 were purified from Origanum vulgare L. and were identified as carvacrol and thymol, respectively. Antimicrobial and antibiofilm activities of these compounds along with chlorhexidine digluconate using various assays was determined against dental caries causing bacteria Streptococcus mutans. The IC values of carvacrol (M-1) and thymol (M-2) against S. mutans were 65 and 54 µg/ml, respectively. Live and dead staining and the MTT assays reveal that a concentration of 100 µg/ml of these compounds reduced the viability and the metabolic activity of S. mutans by more than 50%. Biofilm formation on the surface of polystyrene plates was significantly reduced by M-1 and M-2 at 100 µg/ml as observed under scanning electron microscope and by colorimetric assay. These results were in agreement with RT-PCR studies. Wherein exposure to 25 µg/ml of M-1 and M-2 showed a 2.2 and 2.4-fold increase in Autolysin gene (AtlE) expression level, respectively. While an increase of 1.3 and 1.4 fold was observed in the super oxide dismutase gene (sodA) activity with the same concentrations of M-1 and M-2, respectively. An increase in the ymcA gene and a decrease in the gtfB gene expression levels was observed following the treatment with M-1 and M-2. These results strongly suggest that carvacrol and thymol isolated from O. vulgare L. exhibit good bactericidal and antibiofilm activity against S. mutans and can be used as a green alternative to control dental caries.
植物来源的有机化合物是传统抗菌剂的一种有吸引力的替代品。因此，从牛至中纯化出了两种化合物，即M-1和M-2，它们分别被鉴定为香芹酚和百里香酚。使用各种测定方法，测定了这些化合物以及葡萄糖酸氯己定对致龋菌变形链球菌的抗菌和抗生物膜活性。香芹酚（M-1）和百里香酚（M-2）对变形链球菌的IC值分别为65和54μg/ml。活死染色和MTT测定表明，这些化合物浓度为100μg/ml时，可使变形链球菌的活力和代谢活性降低50%以上。扫描电子显微镜观察和比色测定显示，M-1和M-2在100μg/ml时可显著减少聚苯乙烯平板表面的生物膜形成。这些结果与RT-PCR研究结果一致。其中，暴露于25μg/ml的M-1和M-2时，自溶素基因（AtlE）表达水平分别增加了2.2倍和2.4倍。而在相同浓度的M-1和M-2作用下，超氧化物歧化酶基因（sodA）活性分别增加了1.3倍和1.4倍。用M-1和M-2处理后，观察到ymcA基因表达增加，gtfB基因表达水平降低。这些结果有力地表明，从牛至中分离出的香芹酚和百里香酚对变形链球菌具有良好的杀菌和抗生物膜活性，可作为控制龋齿的绿色替代品。
