title: [Effect of lemon essential oil on caries factors of Streptococcus sobrinus].
abstract: OBJECTIVE
  To investigate the mechanism of lemon peel essential oil (LPE) on the cariogenicity of Streptococcus sobrinus (Ss).
  
  
  METHODS
  LPE was extracted by the authors, and the minimum inhibition concentration (MIC) was measured by disc diffusion method. The LPE was used as the experimental group with concentrations ranging from 2.250 g/L to 0.281 g/L prepared with trypticase peptone yeast (TPY) culture medium, and TPY culture medium was used as the control group. Ss at the concentration of 10(8) CFU/ml was added to each group, and cultured for 6, 18, 24, 48 hours. Neson-Somogyi method was used to measure the content of reducing sugar, and glucosyltransferase (GTF) activity. The activity of lactate dehydrogenase (LDH) was measured by lactic acid and pyruvic acid continuous monitoring method. The content of water insoluble glucan (WIG) was measured by anthrone method, and the pH value of the culture solution was detected. The value of pH before the experiment and the time difference was alculated as ΔpH.
  
  
  RESULTS
  At the same time point, the activity of GTF and LDH and the concentration of WIG and the value ΔpH decreased gradually with the increase of concentration of LPE. There were significant differences between each experimental group and control group (P < 0.01). The control group had the maximum value, GTF: (6.71 ± 0.61) mIU, LDH: (135.8 ± 1.7) U/L, WIG: (47.15 ± 5.12) mg/L, ΔpH: (2.67 ± 0.01). The highest drug concentration group had the minimum value: GTF: (0.39 ± 0.07) mIU, LDH: (95.0 ± 5.4) U/L, WIG: (2.44 ± 0.38) mg/L, ΔpH: (0.61 ± 0.01).
  
  
  CONCLUSIONS
  The LPE below the MIC could still inhibit the GTF, LDH activity and lead to the decrease of WIG and the acid production.
authors: Department of Preventive Dentistry, Stomatological Hospital, Tianjin Medical University, Tianjin 300070, China.
authors: Yan-fen
authors: YF
authors: Shi
authors: Xiang-yu
authors: XY
authors: Zhang
authors: Hui
authors: H
authors: Han
authors: Shuang-lu
authors: SL
authors: Chen
authors: Wei-xiang
authors: WX
authors: Cheng
mesh_terms: D004305:Dose-Response Relationship, Drug; D005936:Glucans / Q000096:biosynthesis*; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D045022:Lactate Dehydrogenases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000494:pharmacology; D010938:Plant Oils / Q000494:pharmacology*; D016986:Streptococcus sobrinus / Q000187:drug effects* / Q000378:metabolism
chemical_list: D005936:Glucans; D009822:Oils, Volatile; D010938:Plant Oils; D045022:Lactate Dehydrogenases; D005964:Glucosyltransferases; C501365:lemon oil