Antimicrobial activity, toxicity and stability of phytol as a novel surface disinfectant

Background: Although various surface disinfectants have been introduced, most of them are toxic. The use of natural antimicrobial agent e.g. phytol, extracted from Leptadenia pyrotechnica is a new strategy. The aim of this study was to evaluate the antimicrobial activity, toxicity, and stability of phytol. Methods: The serial concentrations of phytol were prepared, and separately incubated with four microbial isolates. Then, its Minimum Inhibitory Concentration (MIC) was measured for each microorganism. For toxicity test, serial concentrations (62.5, 125, 250, 500 and 1000 μg/mL) of phytol were incubated with mouse skin cells, and then cell viability was calculated by MTT assay. For stability test, three common surfaces (stone, steel, and MDF) were considered. Then, 100 μL of phytol was separately spread over their surface, and they have been kept at lab panel for 12, 24 and 36 hours. After incubation, two samples were obtained from each surface and inoculated on nutrient agar plates. Finally, colony count was read for each surface. T-test was used to evaluate the significant differences between groups, and P>0.05 considered as level of significant difference. Results: The MIC50 of phytol against E.coli, C.albicans, and A.niger was 62.5 μg/mL, and against S.aureus was >1000 μg/mL. MTT assay showed that the toxicity of phytol was dose and time dependent. The stability test demonstrated that phytol was stable on the stone, MDF, and steel surfaces until 36 hours. Conclusion: It can be concluded that phytol has high antimicrobial activity, high stability, and low toxicity. This substance must be evaluated at actual conditions. Keywords: Antimicrobial activity, Phytol, Toxicity, Stabilit