In vitro comparison of the antimicrobial activity of five herbal extracts, and selected mouthwashes marketed in Egypt against cariogenic streptococcus mutans

ABSTRACT

Dental caries is a multifactorial human disease that has widely affected many populations all over the world. Streptococcus mutans plays a major role in dental caries development. Few of mouthwashes, however, have undergone rigorous testing and lack the quality of an ideal agent as evidenced by the limited amount of information on their safety and efficacy in the literature. Thus presently the antibacterial activity of herbal agents is being extensively studied. The present study aims to compare the antimicrobial effects of 70% aqueous ethanol extract obtained from traditional Egyptian plants with the most common Egyptian mouthwashes brands against S.mutans. S.mutans isolated on Mitis Salivarius Agar [MSA] and confirmed by API 20 Strep C. 70% aqueous ethanol extracts of Achillea fragrantissima Sch.Bip [No 5], Euphorbia hirta L. [No 2], Nymphaea alba L. [No 1], Thymus vulgaris L.[No 4] and Plectranthus amboinicus L [No 3] were prepared.The susceptibility pattern of 25 S. mutans bacterial isolates obtained from 82 dental plaque samples of patients having dental caries to the selected mouthwashes and plant extracts was determined using the agar well diffusion method. The zones of inhibition produced by the mouthwashes and herbal extracts against the bacterial isolates were measured compared with chlorhexidine positive control. Chlorhexidine formulations listermix and jase were the most effective mouthwash preparations, while chlorhexidine free formulation betadine was the least effective preparation against S.mutans. Extracts No 1 and 2 exhibited the highest antimicrobial effect, while extract No 4 showed the least one. Chlorhexidine formulations Jase and listermix are considered to be the most effective mouthwash anticaris. N. alba, E. hirta plant extracts have the greatest antibacterial activity against S.mutans. If similar results are confirmed in clinical trials, these plant extracts can be used alone or in combination to produce new, useful and economic antimicrobial mouthwashes alternative to commonly known mouthwashes with less side effects