Antibiofilm and Antifungal Activities of Laurelia sempervirens (Chilean laurel) Essential Oil

Background: Laurelia sempervirens, better known as Chilean laurel, is endemic to Chile. For many years, the leaves and branches of this plant have been popularly used as medicinal agents. However, its anti-fungal properties and anti-biofilm activity against bacterial strains have not been studied. Objectives: To determine anti-biofilm and anti-microbial properties of Chilean laurel essential oil on human pathogenic strains. Methods: The anti-fungal and anti-bacterial activities of Chilean laurel essential oil were evaluated through the agar diffusion method, and its minimum inhibitory concentration was determined using the standard microdilution method. Antibiofilm activity was examined based on the formation and disruption of bacterial biofilms and evidenced by the crystal violet technique. Results: The results showed important anti-microbial activity against human pathogenic yeast strains, and the minimum inhibitory concentration of Chilean laurel essential oil was 64 µg mL^-1 against Candida albicans. The essential oil also showed an important inhibitory effect against the formation of biofilms produced by Staphylococcus aureus, since it inhibited the formation of biofilms by over 50% at the concentration of 64 µg mL^-1. With increasing the essential oil’s concentration to 128 µg mL^-1, its anti-biofilm activity increased by 60%. Conclusions: These results approve the domestic use of Chilean laurel essential oil as an anti-microbial agent and provide knowledge about the anti-biofilm and anti-fungal properties of L. sempervirens.