Evaluation of antibacterial potential of Aloe vera extracts against Streptococcus mutans and Lactobacillus acidophilus - An in vitro study

Background: Use of antimicrobial agents is one of the important strategies to prevent dental caries. Many synthetic formulations are currently prescribed to reduce the oral microbial load but they suffer from certain disadvantages. Herbal products can be potential alternative sources of antimicrobial agents against cariogenic microorganisms. Objectives: To assess the invitro antibacterial property of Aloe vera extracts against Streptococcus mutans and Lactobacillus acidophilus Materials and Methods: Whole leaf and gel extracts of Aloe vera were prepared using ethanol as the solvent by cold extraction method. The antimicrobial activity of Aloe vera leaf and gel extracts against S.mutans and L.acidophilus was assessed by cup plate method. It was followed by assessment of its minimum inhibitory concentration (MIC) by two fold serial dilution method. Chlorhexidine (0.2%) and dimethlysulphoxide served as positive and negative control in the study respectively. Results: Leaf and gel extracts of Aloe vera did not produce any zone of inhibition against S.mutans. The inhibition zones observed against L.acidophilus were 18 mm and 20 mm respectively for 50,il and 75,il of 50% leaf extract of Aloe vera. The MIC of Aloe vera leaf extract against S.mutans was 300^g/ml and for L.acidophilus it was 780^g/ml. Conclusions: Ethanolic extracts of Aloe vera were found to have antibacterial property against S.mutans andL.acidophilusAloe vera leaf extract has better antibacterial potential than its gel extract against the selected microorganisms.