Comparative Evaluation of Antimicrobial Activity of Pomegranate-Containing Mouthwash Against Oral-Biofilm Forming Organisms: An Invitro Microbial Study

Abstract

Introduction: Pomegranate is considered "A pharmacy unto itself". Hydrolysable tannins called punicalagins which have free scavenging properties are the most abundant polyphenols found in pomegranate-containing mouthwash.

Aim: To evaluate antimicrobial effect of pomegranate- containing mouthwash on oral biofilm-forming bacteria.

Materials and methods: The mouthwashes used were divided into three groups- Group A: Chlorhexidine mouthwash (Hexidine); Group B: Herbal Mouthwash (Hiora) and Group C: Pomegranate-containing Mouthwash (Life-extension). Each mouthwash was diluted to five different concentrations. Reference strains of Streptococcus mutans (S.mutans) (ATCC 25175), Streptococcus salivarius (S.salivarius) (ATCC 7073), and Aggregatibacter actinomycetemcomitans (A.a) (NCTC 9710) were selected as being colonizers in dental biofilm formation. On each culture plate, five wells of 5mm were prepared and mouthwashes with different concentrations were added, followed by incubation in a CO2 jar for 24 hours at 37°C. Inhibition zone diameters were measured using a digital caliper.

Results: Chlorhexidine (0.12%) presented a zone of inhibition between 38.46% to 96.15% for all the three organisms, while Hiora presented zone of inhibition ranging from 33.33% to 69.23% but was resistant at <10 ml of dilution. Pomegranate mouthwash presented a zone of inhibition ranging from 38.48 to 57.69%, but was resistant at <10ml for S.mutans, and <25ml for A.a and S.salivarius. ANOVA test was done to compare the dilution of mouthwashes for a particular organism and Tukey's multiple comparison tests were done to find the exact difference. A significant difference was seen between all the three groups at 50ml and 75 ml of dilution. At 75 ml concentration, a statistical difference was found between Groups B & C and Groups A & B; and at 50 ml between Groups A&C.

Conclusion: All the three types of mouthwash exhibit anti-microbial activity against biofilm forming organisms but at varying concentrations. Although Chlorhexidine still continues to be the gold standard, pomegranate-containing or herbal mouthwashes can be easily substituted for long term use, avoiding the side effects of chlorhexidine.

Keywords: Aggregatibacter actinomycetemcomitans; Biofilms; Chlorhexidine; Mouthwashes; Plaque; Streptococcus mutans; Streptococcus salivarius.

[Table/Fig-3]:

Bar diagram showing difference between three mouthwash at different concentration for Streptococcus mutans.

[Table/Fig-4]:

Bar diagram showing difference between three mouthwashes at different concentration for Streptococcus salivarius.

[Table/Fig-5]:

Bar diagram showing difference between three types of mouthwash at different concentration for Aggregatibacter actinomycetemcomitans.