*2.2. Proliferation and Cell Viability Assay*

The suppressive effect of EO was assessed in HepG2 liver cancer cell lines and normal fibroblast NIH-3T3 cell lines. Cell viability and proliferation were determined colorimetrically by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. HepG2 and NIH-3T3 cell lines were treated with various concentrations (0, 5, 10, 25, 50, and 100 μg/mL) of EO for 24 h. The results revealed that proliferation was potentially inhibited in HepG2 cancer cells in a dose-dependent manner. The IC50 of EO in the cell lines was 11.3 μg/mL and 52.1 μg/mL for HepG2 and NIH-3T3, respectively. The sub-lethal dose was considered to be 10–25 μg/mL, showing survival rates of 52.2% and 36.2% in HepG2 and NIH-3T3, respectively. These concentrations were used for further experiments (see Figure 2). On the other hand, NIH-3T3 cell lines showed higher cell proliferation and viability, and it was insignificantly inhibited up to 25 μg/mL of EO.


**Table 1.** Volatile constituents of EO from *A. lanatum*.

Values were obtained from three replicates. Mean ± standard deviation (SD) is shown. Rt, retention time; RI (exp), experimental relative retention index; RI (lit), literature relative retention index from MS libraries (Wiley) National Institute of Standards and Technology (NIST); RA, relative abundance; MS, mass spectra values.

Total non-terpene derivatives 0.20 (1) Total identified constituents 94.68 (38)

**Figure 2.** Effect of EO from *A. lanatum* on cell viability. EO inhibited cell growth and cell proliferation in HepG2 liver cancer cells and NIH-3T3 normal murine fibroblast cells: (**A**) HepG2 and NIH-3T3 cell lines were supplemented with EO (0–100 μg/mL) or a vehicle control (0.1% DMSO) for 48 h periods, and cell viability was assessed by MTT assay, and (**B**) HepG2 and NIH-3T3 cells were supplemented with EO (0–100 μg/mL) for 24 h, and cell morphology was examined beneath a phase-contrast microscope. The data are shown as the mean ± SD of triplicate measurements; \* *p* < 0.05 when evaluated with respect to control cells.
