Investigation of herbal and chemical properties and biological activities of lemon basil (Ocimum citriodorum) grown in cadmium and lead contaminated soils

Within the scope of this thesis study, Ocimum citriodorum (lemon basil) was grown in Çankırı conditions in 2021-2022 as a pot experiment using contaminated soils at Pb (100, 200, 400 mg kg-1) and Cd (5, 10, 20 mg kg-1) concentrations. The experiment was conducted with 4 replicates. The yield, quality, essential oil and phenolic constituents, phytoremediation and anticancer activities of the leaves dried after harvest were analysed. Accordingly, variations fresh and dry root weight, fresh and dry herb weight, dry matter content in root and herb, plant height, leaf width and length, stem diameter, flowering stem length, dry leaf weight, essential oil and extract yields determined during the years 2021 and 2022 vegetation season. Then, essential oils and phenolics were determined by GC/MS and LC/MS, respectively. The anticancer activities of the methanol extracts and essential oils against HeLa and PC3 cell lines were investigated. Finally, heavy metal accumulation in leaves and roots was determined by ICP/MS and its use in phytoremediation was evaluated. According to these data, the morphological characteristics, essential oil and extract yields of O. citriodorum grown in Pb and Cd contaminated soil were generally decreased compared to the control. The main component of the essential oil was citral and the main phenolic component was trans-ferulic acid in the control and both heavy metal concentrations. At Cd and Pb concentrations, an increase was observed in the accumulation of heavy metals in roots and leaves compared to the control and it was determined that the accumulation was higher in roots than in leaves. Thus, it was determined that it showed hyperaccumulatory properties for Cd and Pb and could be evaluated as phytostabiliser in phytoremediation. The inhibition effect of the methanol extracts against HeLa cell at 100 µg/mL concentrations was determinated as Cd10>Cd20~Cd5>5-FU>Control, ii) Pb200>5-FU>Control>Pb100>Pb400, and the inhibition effect against PC3 cell at 100 µg/mL concentrations was determined as i) Cd20~Cd10>Cd5>Control>5-FU, ii) Pb400~Pb200>Pb100>Control>5-FU. The inhibition effect of the obtained essential oils against HeLa cell at 100 µg/mL concentrations was determined as Cd5>Cd10~Cd20>5-FU>Control and Pb400>Pb200~Pb100>5-FU>Control. and the inhibition effect against PC3 cell at 100 µg/mL concentrations was determined as Cd20~Cd10>Cd5>Control>5-FU and Control>Pb200>Pb100~Pb400>5-FU.