Evaluation of the possible potential of essential oils present in emulsion or under vapour against Covid-19
The essential oils (EOs) and their chemical constituents are known to be active against a wide range of viruses like herpes simplex virus type 1 (HSV 1) (Astani et al., 2010). The active compounds in essential oils are normally related to the presence of terpenes, especially monoterpenes and phenolic compounds which are the volatiles part in essential oils. Some reports on natural extracts and essential oils have demonstrated antiviral activity against coronaviruses to some extent in both emulsion phase and vapor phase (Mani et al., 2020). Since the new strain of coronavirus, Covid-19, is still not completely understood, it is not yet possible to find which EOs will offer the best level of protection. However, it is plausible to assume that some of the EOs and related terpenes are likely to offer a measurable level of defense in the same way that they do with other known viruses such as HSV 1. We have demonstrated in several studies that EOs in vapor or in solution can inhibit bacteria and fungus, and even virus i.e. norovirus (flavonoids from citrus extract) (Gobeil et al., 2020). The main objectives of the proposal are: (1) Evaluate the minimum inhibitory concentrations (MIC) and fractional inhibitory concentrations (checkerboard method) of EOs (FIC calculation: evaluation of the synergy between EOs) under emulsion form against Covid-19 using broth microdilution and checkerboard method; (2) Evaluate the MIC and FIC of EOs in vapor form against Covid-19 using a new broth volatilization checkerboard method; (3) Develop EOs formulation that could be applied under solution or vapor form on Covid-19. The results of the study will permit to develop anti Covid-19 formulations under the form of emulsion or for vapor application for diverse applications such as working or food surface or even for air decontamination.