Table 1 In vitro antiviral and cytotoxic activities of twelve essential oils expressed in half-maximal effective concentration (EC50), half-maximal cytotoxic concentration (CC50), and therapeutic index (TI).

From: Essential oils block cellular entry of SARS-CoV-2 delta variant

Essential oils

Concentrations in µg/mL (95% confidence interval )

TI (CC50/EC50)

EC50

CC50

Zingiber officinale

33.7 (20.9–55.3)

38.6 (22.3–70.2)

1.12

Eucalipto globulus

12.9 (6.4–25.3)

23.9 (15.2–37.7)

1.85

Thymus vulgaris

3.1 (1.3–7.4)

2.0 (1.5–2.8)

0.67

Illicium verum”

0.5 (0.3–0.8)

29.5 (17.7–51.7)

60.00

Rosmarinus officinalis

57.1 (35.2–93.3)

81.1 (43.2–169.0)

1.42

Melaleuca alternifolia

29.2 (18.6–46.7)

41.0 (27.9–60.9)

1.41

Syzygium aromaticum

0.09 (0.07–0.13)

0.42 (0.30–0.58)

4.44

Cymbopogon citratus

0.11 (0.07–0.19)

0.20 (0.12–0.22)

2.00

Origanum vulgare

0.36 (0.23–0.57)

0.41 (0.31–0.56)

1.00

Citrus limon

0.15 (0.09–0.22)

1.3 (0.7–2.3)

8.67

Pelargonium graveolens

0.20 (0.14–0.29)

1.7 (1.1–2.6)

8.50

Matricaria recutita

1.1 (0.6–1.9)

1.2 (0.8–1.7)

1.09