Assessment of Cytotoxic and Apoptotic Effects of Salvia syriaca L. in Colorectal Adenocarcinoma Cell Line (Caco-2)

This work is aimed to elucidate cytotoxic and apoptotic effects of Salvia syriaca essential oil and its chemical composition by GC-MS. The human colon cancer cells (Caco-2) were treated with different essential oil concentrations for 24 h. Crystal violet test was used to determine cell viability at 630 nm by using an ELISA reader. Apoptotic processes were measured by Annexin V-FITC Apoptosis Assay Kit. Germacrene D (21.77%), trans-β-ocimene (14.66%), β-pinene (9.07%), α-cadinol (8.19%) and α-pinene (6.50%) were the main components of oil determined by GC-MS. Moreover, we observed that the cytotoxic effect was increased with an increasing dose of essential oil. The EC50 value was calculated as 63.5 µg/mL. An increase in the percentage of apoptotic cells was observed after treatment of Caco-2 cells with S. syriaca essential oil revealed by image-based cytometry. A nearly 6-fold increase was found in annexin-positive cells after treatment. In terms of mRNA levels, RT-PCR analysis indicated that, although Bax and Caspase-3 were increased, Bcl-2 was decreased after oil treatment. According to our results, S. syriaca essential oil has promising phytochemicals that might be useful in cancer treatment due to their relatively cytotoxic and apoptotic activities in Caco-2 cells.