Evaluation of antimicrobial and cytotoxic effects of Echinacea and Arctium extracts and Zataria essential oil

Abstract

AbstractDental caries and oral infections have become a widespread issue in the modern world. This study aimed to investigate the antibacterial, antifungal, and cytotoxicity characteristics of the extracts ofEchinacea purpura,Arctium lappa, and the essential oil ofZataria multifloraas a potential herbal mouthwash. The essential oil ofZ. multifloraleaves and the extracts ofE. purpurea and A. lapparoots were prepared. The characterization was carried out by GC-MS and also, total phenol and flavonoid were assed for all three samples. The antimicrobial and anti-biofilm effects were evaluated againstStreptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Lactobacillus acidophilus, Escherichia coli, Staphylococcus aureus,andCandida albicans.The cytotoxic effect of the samples was evaluated on HEK 293 and HDFa cells by MTT test. Thymol and carvacrol contents in EO ofZ. multiflorawere measured at 31% and 42.2%, respectively.A. lappahad the lowest total phenolic and flavonoid value among the samples. On the other hand, the total phenolic content ofZ. multifloraand the total flavonoid content ofE. purpureawere the highest. The MIC values ofZataria,Arctium, andEchinaceaagainstS. mutanswere 0.011% v/v, 187.5 mg/ml, and 93.75 mg/ml, while MBC were 0.011% v/v, 375 mg/ml, and 187.5 mg/ml, respectively. The formulation showed bactericidal activity againstS. mutansin the concentration of 5.86 mg/ml for Echinacea and Burdock extracts and 0.08 µl/ml for EO ofZataria.The formulation significantly affected microbial biofilm formation and induced biofilm degradation. The cell viability percentages were higher than 50% during 24 and 48 h. The formulation had a significant antimicrobial effect on cariogenic bacteria andC. albicans, with the lowest cytotoxic effects. Therefore, this formulation can be an appropriate candidate for mouthwash.