A Mixture of Essential Oils from Three Cretan Aromatic Plants Inhibits SARS-CoV-2 Proliferation: A Proof-of-Concept Intervention Study in Ambulatory Patients

Christos Lionis; Elena Petelos; Manolis Linardakis; Athanasios Diamantakis; Emmanouil Symvoulakis; Maria-Nefeli Karkana; Marilena Kampa; Stergios A Pirintsos; George Sourvinos; Elias Castanas

doi:10.3390/diseases11030105

A Mixture of Essential Oils from Three Cretan Aromatic Plants Inhibits SARS-CoV-2 Proliferation: A Proof-of-Concept Intervention Study in Ambulatory Patients

Diseases. 2023 Aug 9;11(3):105. doi: 10.3390/diseases11030105.

Authors

Affiliations

¹ Clinic of Social and Family Medicine, School of Medicine, University of Crete, 71003 Heraklion, Greece.
² Department of Health, Medicine and Care, General Practice, Linköping University, SE-581 85 Linköping, Sweden.
³ Department of Health Services Research, CAPHRI-Care and Public Health Research Institute, Maastricht University, 6229 HX Maastricht, The Netherlands.
⁴ Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71003 Heraklion, Greece.
⁵ Department of Biology, School of Sciences and Technology, University of Crete, 71003 Heraklion, Greece.
⁶ Botanical Garden, University of Crete, 71003 Rethymnon, Greece.
⁷ Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece.

Abstract

Introduction: The need for effective therapeutic regimens for non-critically ill patients during the COVID-19 pandemic remained largely unmet. Previous work has shown that a combination of three aromatic plants' essential oils (CAPeo) (Thymbra capitata (L.) Cav., Origanum dictamnus L., Salvia fruticose Mill.) has remarkable in vitro antiviral activity. Given its properties, it was urgent to explore its potential in treating mild COVID-19 patients in primary care settings.

Methods: A total of 69 adult patients were included in a clinical proof-of-concept (PoC) intervention study. Family physicians implemented the observational study in two arms (intervention group and control group) during three study periods (IG_{2020, n=13}, IG_{2021/22, n=25}, and CG_{2021/22, n=31}). The SARS-CoV-2 infection was confirmed by real-time PCR. The CAPeo mixture was administered daily for 14 days per os in the intervention group, while the control group received usual care.

Results: The PoC study found that the number and frequency of general symptoms, including general fatigue, weakness, fever, and myalgia, decreased following CAPeo administration. By Day 7, the average presence (number) of symptoms decreased in comparison with Day 1 in IG (4.7 to 1.4) as well as in CG (4.0 to 3.1), representing a significant decrease in the cumulative presence in IC (-3.3 vs. -0.9, p < 0.001; η² = 0.20) on Day 7 and on Day 14 (-4.2 vs. -2.9, p = 0.027; η² = 0.08).

Discussion/conclusions: Our findings suggest that CAPeo possesses potent antiviral activity against SARS-CoV-2 in addition tο its effect against influenza A and B and human rhinovirus HRV14 strains. The early and effective impact on alleviating key symptoms of COVID-19 may suggest this mixture can act as a complementary natural agent for patients with mild COVID-19.

Keywords: COVID-19; SARS-CoV-2; effectiveness; essential oils; natural products.

Grants and funding

The clinical study, which received approval from the Bioethics Committee of the University of Crete), was exclusively supported by the capacity of the Clinic of Social and Family Medicine at the University of Crete. CAPeo, in the form of soft capsules, was provided by Olvos Science SA.