comparative evaluation of antibacterial effect of three commercially available herbal products against streptococcus mutans: an in vitro study

Background: In recent years, the researches concerning the use of herbal products have been vastly analyzed to decrease the disease burden caused by dental caries. It has been found that certain phytochemicals present in the plants have certain inhibitory effect toward Streptococcus mutans which is currently the main causative organism for dental caries initiation. Hence, in the present study, certain commercial herbal products have been tested for their antibacterial effect. Aim: This study aims to compare the antibacterial action of three commercially available herbal products against S. mutans. Material and Methods: An in vitro study was conducted with commercially available herbal products. They were Aloe Barbadensis Miller (Aloe vera), Ocimum tenuiflorum (Thulasi), and Stevia rebaudiana (Stevia). The antimicrobial effectiveness (zone of inhibition) of herbal products was determined using agar well diffusion method. Pure strains of S. mutans MTCC 890 were procured from culture collection center, Imtech, Chandigarh. The culture was grown in Brain Heart Infusion Agar, and around 20 ml each was poured into sterile petri plates. Chlorhexidine (CHX) was taken as positive control, and distilled water was taken as negative control. Statistical analysis was done using SPSS version 17 software. Results: All herbal products were found to be having variable antimicrobial activity against S. mutans. The mean zone of inhibition after 24 h incubation measured for Stevia, Thulasi, and A. vera was 22.33 mm, 11 mm, and 0 mm, respectively. The mean zone of inhibition of positive control CHX was found to be 13.6 mm. Conclusion: The antibacterial effect shown by Stevia was superior when compared with CHX and Thulasi. The Thulasi have more inhibitory effect than A. vera, and A. vera fails to show any zone of inhibition against S. mutans when compared with other herbal products. Thus, Stevia product can be strongly recommended as a caries preventing agent after sufficient clinical trials by future research.