title: Effect of aqueous and alcoholic Stevia (Stevia rebaudiana) extracts against Streptococcus mutans and Lactobacillus acidophilus in comparison to chlorhexidine: An in vitro study.
abstract: BACKGROUND
  Stevia (S. rebaudiana) a herb which has medicinal value and was used in ancient times as a remedy for a great diversity of ailments and sweetener. Leaves of Stevia contain a high concentration of Stevioside and Rebaudioside which are supposed to be sweetening agents.
  
  
  OBJECTIVE
  To compare the efficacy of aqueous and alcoholic S. rebaudiana extract against Streptococcus mutans and Lactobacillus acidophilus in comparison to chlorhexidine.
  
  
  METHODS
  In the first part of the study, various concentrations of aqueous and ethanolic Stevia extract were prepared in the laboratory of Pharmacy College. It was then subjected to microbiological assay to determine its zone of inhibition using Agar disk diffusion test and minimum inhibitory concentration (MIC) using serial broth dilution method against Streptococcus mutans and Lactobacillus acidophilus. Chlorhexidine was used as a positive control. One way Analysis of Variance (ANOVA) test was used for multiple group comparisons followed by Tukey post hoc for group wise comparisons.
  
  
  RESULTS
  Minimum inhibitory concentration (MIC) of aqueous and ethnolic Stevia extract against Streptococcus mutans and Lactobacillus acidophilus were 25% and 12.5% respectively. Mean zone of inhibition of the aqueous and alcoholic Stevia extracts against Streptococcus mutans at 48 hours were 22.8 mm and 26.7 mm respectively. Mean zone of inhibition of the aqueous and alcoholic Stevia extracts against Lactobacillus acidophilus at 48 hours were 14.4 mm and 15.1 mm respectively. Mean zone of inhibition of the chlorhexidine against Streptococcus mutans and Lactobacillus acidophilus at 48 hours was 20.5 and 13.2 respectively.
  
  
  CONCLUSIONS
  The inhibitory effect shown by alcoholic Stevia extract against Streptococcus mutans and Lactobacillus acidophilus was superior when compared with that of aqueous form and was inferior when compared with Chlorhexidine.
authors.affiliation: Department of Public Health Dentistry, Kurunji Venkatramana Gowda Dental College and Hospital, Kurunjibhag, Sullia, India.
authors.forename: Sunil Lingaraj
authors.initials: SL
authors.lastname: Ajagannanavar
authors.affiliation: Department of Public Health Dentistry, Coorg Institute of Dental Sciences, Maggula, Virajpet Karnataka, India.
authors.forename: Supreetha
authors.initials: S
authors.lastname: Shamarao
authors.affiliation: Department of Public Health Dentistry, Kurunji Venkatramana Gowda Dental College and Hospital, Kurunjibhag, Sullia, India.
authors.forename: Hemant
authors.initials: H
authors.lastname: Battur
authors.affiliation: Department of Preventive Dental Sciences, Division of Dental Public Health, King Khalid University, College of Dentistry, Abha, Saudi Arabia.
authors.forename: Shreyas
authors.initials: S
authors.lastname: Tikare
authors.affiliation: Department of Dental Health, Dental Biomaterials Research Chair, College of Applied Medical Sciences, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Abdulaziz Abdullah
authors.initials: AA
authors.lastname: Al-Kheraif
authors.affiliation: College of Engineering, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Mohammed Sayed Al Esawy
authors.initials: MS
authors.lastname: Al Sayed
keywords: Chlorhexidine; Stevia; Stevia rebaudiana