Biological Activities and Phytochemical Screening of Thuja occidentalis Extracts with In Silico Approaches

The evergreen coniferous tree Thuja occidentalis is a member of the Cupressaceae family. This study included biological, cytotoxic, and in silico docking analyses in addition to a phytochemical composition analysis of the plant leaves and stem ethanolic extracts. The extracts' in vitro cytotoxicity efficacy against various cancer cell lines was examined. Additionally, certain phytochemical compounds were identified by gas chromatographic analysis and subsequently assessed in silico against anticancer molecular targets. Also, their antiviral effect was assessed. Good cytotoxic activity was demonstrated by plant extracts against the lung and colorectal cancer cell lines. With half-maximal inhibitory concentration values of 18.45 μg/mL for the leaf extract and 33.61 μg/mL for the stem extract, apoptosis and S-phase arrest was observed in the lung cancer cell line. In addition, the leaf extract demonstrated effective antiviral activity, with suppression rates of 17.7 and 16.2% for the herpes simplex and influenza viruses, respectively. Gas chromatographic analysis revealed the presence of relevant bioactive components such as Podocarp-7-en-3β-ol, 13β-methyl-13-vinyl, Megastigmatrienone, and Cedrol, which were tested in silico against anticancer molecular targets. Our findings suggest that plant ethanolic extracts may have potential therapeutic uses as anticancer drugs against lung cancer in addition to their antiviral properties, which opens up further avenues for more investigation and applications.