In vitro antibacterial effect of Pimpinella anisum essential oil on Enterococcus faecalis, Lactobacillus casei, Actinomyces naeslundii, and Aggregatibacter actinomycetemcomitans

Abstract

Introduction: Pimpinella anisum is a medicinal plant with antimicrobial, antifungal, and anti-oxidative properties. Limited studies have assessed the antibacterial properties of Pimpinella anisum on oral and dental pathogens. Aim: This in vitro study aimed to assess the antibacterial effect of Pimpinella anisum essential oil on Enterococcus faecalis, Lactobacillus casei, Actinomyces naeslundii, and Aggregatibacter actinomycetemcomitans. Materials and methods: After obtaining the essential oil of Pimpinella anisum, its antimicrobial activity was evaluated using the agar disc diffusion test. The minimum inhibitory concentration and minimum bactericidal concentration of the essential oil were also determined; 0.2% chlorhexidine was used as the positive control. Results: The mean diameter of growth inhibition zone was 39 mm for Enterococcus faecalis, 40 mm for Lactobacillus casei, 42 mm for Actinomyces naeslundii, and 18.5 mm for Aggregatibacter actinomycetemcomitans. The mean diameter of the growth inhibition zones for Enterococcus faecalis, Lactobacillus casei, and Actinomyces naeslundii was significantly greater than that of Aggregatibacter actinomycetemcomitans (p=0.001). Also, the mean diameter of the growth inhibition zone of Actinomyces naeslundii was significantly larger than that of Enterococcus faecalis (p=0.05). The minimum inhibitory concentration and minimum bactericidal concentration of the essential oil for Enterococcus faecalis were 4.88% and 4.88%, respectively. These values were 9.76% and 9.76% for Lactobacillus casei, 9.76% and 4.88% for Actinomyces naeslundii, and 9.76% and 9.76% for Aggregatibacter actinomycetemcomitans, respectively. Conclusions: Pimpinella anisum essential oil was effective against all four microorganisms evaluated in this study. Since the lowest minimum inhibitory concentration and minimum bactericidal concentration were recorded for Enterococcus faecalis, this essential oil has maximum effects on Enterococcus faecalis. Future clinical studies are required to assess the antimicrobial efficacy of Pimpinella anisum essential oil in clinical samples.