Eucalyptus oil as adjuvant therapy for coronavirus disease 19 (covid-19): a randomized clinical trial

Introduction: The coronavirus disease 19 (COVID-19) vaccination scheme is still being implemented worldwide, but problems with stock availability and other factors are still impeding this endeavor, especially in developing nations like Indonesia. Ethnopharmacology is known to provide a good source of a cheap candidate for anti-inflammation drugs. This study was conducted to determine the effectiveness of affordable adjuvant therapy, Eucalyptus oil, which has been used as a household remedy for respiratory tract infections in Indonesia.Methods: 52 mild-moderate COVID-19 patients were randomly assigned for a prospective clinical trial. A group of 26 patients was given standard COVID-19 treatment as a control group, while another 26 patients as the treated group were given standard therapy and use Eucalyptus oil as an adjuvant. The clinical sign and symptoms, cytokines interleukin (IL) 6, IL-10, and transforming growth factor-beta (TGF-13) profiles were recorded during the study period.Result: There was a trend of better improvement of clinical symptoms among patients who received adjuvant treatment than the control group. Altered smell (p = 0.003) and cough (p = 0.641) recovered faster in the treated group. While there was no marked difference in IL-10 and TGF-13 levels among both groups, IL-6 level in the treated group was significantly lower and the neutrophil-to-lymphocyte ratio (NLR) was significantly decreased (p < .05) than the control.Conclusion: Using Eucalyptus oil as an adjuvant of COVID-19 treatment promotes faster recovery of mild-moderate COVID-19 patients, probably via inhibition of the IL-6-mediated inflammation process.