Table 2  Antiviral activities of essential oil components.
Essential Oil Component  Assay  IC50 (μg/mL)  Reference
(E)−Anethole  Plaque reduction assay (RC-37 cells), HSV-1  20  [59]
Camphor  Plaque reduction assay (Vero cells), HSV-1  2600  [72]
Carvacrol  MTT assay (Mardin−Darby bovine kidney (MDBK) cells, HSV-1  48.6  [63]
β-Caryophyllene  Plaque reduction assay (RC-37 cells), HSV-1  0.25  [59]
Caryophyllene oxide  Plaque reduction assay (RC-37 cells), HSV-1  0.7  [59]
1,8-Cineole  Plaque reduction assay (Vero cells), HSV-1  1800  [72]
1,8-Cineole  Plaque reduction assay (RC-37 cells), HSV-1  1200  [52]
(E)-Cinnamaldehyde  Influenza type A (H1N1) virus  70% at a concentration of 0.53% after 3 h  [95]
(E)-Cinnamaldehyde  H1N1 in-vivo by inhalation in a mouse model  89% inhibition  [95]
Citral (Geranial + Neral)  Yellow fever (YFV), Vero cells  17.6  [62]
Citral (Geranial + Neral)  Plaque reduction assay (RC-37 cells), HSV-1  3.50  [52]
p-Cymene  Influenza, HSV-1, HSV-2, ECHO 9, Cox B1, Polio 1, Adeno 6  >500  [31]
p-Cymene  Plaque reduction assay (RC-37 cells), HSV-1  16  [52]
p-Cymene   Influenza type A (H1N1) virus  Inactive  [25]
Dodecanal   Influenza type A (H1N1) virus  51  [54]
β-Eudesmol  Plaque reduction assay (Vero cells), HSV-1  6  [59]
Eugenol  Plaque reduction assay (RC-37 cells), HSV-1  35  [59]
Eugenol  Plaque reduction assay (RC-37 cells), HSV-1  25.6  [96]
Farnesol  Plaque reduction assay (RC-37 cells), HSV-1  3.5  [59]
Germacrone  Influenza type A (H1N1) virus  1.22–1.55  [97]
Germacrone  Influenza type A (H3N2) virus  0.34  [97]
Germacrone  Influenza type B virus  1.38  [97]
Isoborneol  Plaque reduction assay (Vero cells), HSV-1  <1000  [98]
Nerolidol (natural)  Plaque reduction assay (RC-37 cells), HSV-1  4.2  [99]
Nerolidol (synthetic)  Plaque reduction assay (RC-37 cells), HSV-1  1.5  [99]
Octanal  Influenza type A (H1N1) virus  15  [54]
Patchouli alcohol  Influenza type A (H1N1)  89% inhibition at 10 μg/mL  [100]
Patchouli alcohol  Influenza type A (H2N2)  0.89  [101]
Patchouli alcohol  Influenza type A (H2N2), in-vivo test using a mouse model  70% survival rate at a dose of 5 mg/(kg day)  [101]
α-Pinene  Plaque reduction assay (RC-37 cells), HSV-1  4.5  [52]
Piperitenone oxide  Plaque reduction assay (Vero cells)  1.4  [64]
α-Terpinene  Influenza type A (H1N1) virus  Inactive  [25]
α-Terpinene  Influenza, HSV-1, HSV-2, ECHO 9, Cox B1, Polio 1, Adeno 4  >12  [31]
α-Terpinene  Plaque reduction assay (RC-37 cells), HSV-1  8.5  [52]
γ-Terpinene  Plaque reduction assay (RC-37 cells), HSV-1  7  [52]
γ-Terpinene  Influenza, HSV-1, HSV-2, ECHO 9, Cox B1, Polio 1, Adeno 5  >120  [31]
γ-Terpinene  influenza type A (H1N1) virus  inactive  [25]
Terpinen-4-ol  Influenza, HSV-1, HSV-2, ECHO 9, Cox B1, Polio 1, Adeno 2  25 (influenza)>50 (others)  [31]
Terpinen-4-ol  Plaque reduction assay (Vero cells), HSV-1  60  [52]
α-Terpineol  Plaque reduction assay (RC-37 cells), HSV-1  22  [52]
Terpinolene  Influenza, HSV-1, HSV-2, ECHO 9, Cox B1, Polio 1, Adeno 3  12 (influenza)>12 (others)  [31]
Thujones (α & β)  Plaque reduction assay (RC-37 cells), HSV-1  400  [72]
Thymol  Influenza type A (H1N1) virus  Active  [25]
Thymol  Plaque reduction assay (RC-37 cells), HSV-1  30  [52]
2-Undecanone  influenza type A (H1N1) virus  62  [54]