title: Effect of aqueous and alcoholic licorice (glycyrrhiza glabra) root extract against streptococcus mutans and lactobacillus acidophilus in comparison to chlorhexidine: an in vitro study.
abstract: BACKGROUND
  Glycyrrhiza (licorice) an herb, which has medicinal value and was used in ancient times as a remedy for a great diversity of ailments and sweetener. Roots of Glycyrrhiza contain a high concentration of saponin and glycyrrhizin, which are supposed to be sweetening agents. The aim of the study was to compare the efficacy of aqueous and alcoholic licorice root extract against Streptococcus mutans and Lactobacillus acidophilus in comparison to chlorhexidine (CHX).
  
  
  METHODS
  In the first part of the study, various concentrations of aqueous and ethanolic licorice 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 S. mutans and L. acidophilus. CHX was used as a positive control.
  
  
  RESULTS
  MIC of aqueous and ethnolic licorice root extract against S. mutans and L. acidophilus were 25% and 12.5%, respectively. Mean zone of inhibition of the aqueous and alcoholic licorice extracts against S. mutans at 48 h were 22.8 mm and 26.7 mm, respectively. Mean zone of inhibition of the aqueous and alcoholic licorice extracts against L. acidophilus at 48 h were 14.4 mm and 15.1 mm, respectively. Mean zone of inhibition of the CHX against S. mutans and L. acidophilus at 48 h was 20.5 and 13.2, respectively.
  
  
  CONCLUSIONS
  The inhibitory effect shown by alcoholic licorice root extract against S. mutans and L. acidophilus was superior when compared with that of aqueous form and CHX.
authors.affiliation: Senior Lecturer, Department of Public Health Dentistry, KVG Dental College & Hospital, Sullia, Dakshina Kannada, Karnataka, India.
authors.forename: Sunil Lingaraj
authors.initials: SL
authors.lastname: Ajagannanavar
authors.affiliation: Reader, Department of Public Health Dentistry, KVG Dental College & Hospital, Sullia, Dakshina Kannada, Karnataka, India.
authors.forename: Hemant
authors.initials: H
authors.lastname: Battur
authors.affiliation: Senior Lecturer, Department of Public Health Dentistry, Coorg Institute of Dental Sciences, Virajpet, Kodagu, Karnataka, India.
authors.forename: Supreetha
authors.initials: S
authors.lastname: Shamarao
authors.affiliation: Senior Lecturer, Department of Public Health Dentistry, PMS College of Dental Sciences and Research, Thiruvananthapuram, Kerala, India.
authors.forename: Vivek
authors.initials: V
authors.lastname: Sivakumar
authors.affiliation: Senior Lecturer, Department of Public Health Dentistry, Kamineni Institute of Dental Sciences, Narketpally, Andhra Pradesh, India.
authors.forename: Pavan Uday
authors.initials: PU
authors.lastname: Patil
authors.affiliation: Senior Lecturer, Department of Dentistry, DM Wayanad Institute of Medical Sciences, Kerala, India.
authors.forename: P
authors.initials: P
authors.lastname: Shanavas
keywords: Chlorhexidine; Glycyrrhiza glabra; licorice