Phytochemical composition and biological activities of selected essential oils and their discrimination through principal component analysis

The present study aimed to determine the phytochemical characterization, anticancer and antioxidant activities of essential oils (EOs) obtained from nine commonly used medicinal and aromatic plants (MAPs) including Cymbopogon citratus (DC) Stapf (Poaceae), Cistus creticus L. (Cistaceae), Foeniculum vulgare Mill. (Apiaceae), Laurus nobilis L. (Lauraceae), Myrtus communis L. (Myrtaceae), Pinus cembra L. (Pinaceae), Echinacea purpurea (L.) Moench, Helichrysum arenarium (L.) Moench, and Inula viscosa (L.) Aiton (Asteraceae) taxa from Türkiye. The chemical composition of the EOs was identified using gas chromatography-mass spectrometry (GC-MS), and their antioxidant activities were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radical scavenging methods. In addition, the anticancer potential of the EOs were assessed using MTT assay against human cell lines, including hepatocellular carcinoma (HepG2), gastric carcinoma (NCI-N87), breast adenocarcinoma (MCF-7), and human prostate carcinoma (LNCaP clone FGC-Luc2) cancer cells, as well as non-cancerous human umbilical vein endothelial cells (HUVECs). The antioxidant activities of the EOs varied from 35.21 to 79.12%. Consistent with their antioxidant activities, the anticancer activities of the EOs of C. citratus, L. nobilis and, C. creticus exhibited significantly higher anticancer activities compared to the others. However, almost all EOs were found to inhibit cell viability and induce apoptosis in cancer cells. Among the tested concentrations, the highest anticancer activity was observed against against MCF-7 cells, followed by NCI-N87, LNCaP, and HepG2 cancer cells, with the IC₅₀ values ranging from 15.10 ± 1.00 to 78.12 ± 0.32 µg/mL, respectively. The major components of the EOs distilled from studied MAPs were found as anethole, borneol, carvacrol, citral, α-pinene, eucalyptol and β-citral at different concentrations in the EOs. Overall, it can be clearly concluded that the EO samples distilled from studied MAPs contain valuable bioactive compounds and accordingly exhibit remarkable biological activities.