Antitumor activity of Lamiaceae plants frequently used in Serbian folk medicine and cuisine.

Abstract

Recently, cancer research has focused on searching for new and more effective antitumor agents of natural origin that can activate multiple defence mechanisms and selectively damage transformed cells. The goal of this research was to assess different antitumor mechanisms of ethanolic extracts of 18 Lamiaceae species traditionally used in Serbian folk medicine and cuisine, as well as their genotoxic potential towards HCT-116 (colorectal cancer) cells. The viability of treated HCT-116 cells was assessed by MTT assay; the production of reactive oxygen species (ROS) by treated HCT- 116 cells was determined using NBT assay, while their production of nitric oxide (NO) was evaluated using Griess assay. The genotoxic activity of the extracts on HCT-116 cells was tested in Comet assay, using etoposide as a positive control. The results indicated that lavender, basil, and rosemary inhibited the proliferation of these cells, significantly lowering their viability. Moreover, lavender and thyme extracts displayed a significant increase in ROS production, whereas ground- ivy, hyssop, lemon balm, peppermint, basil, rosemary, sage, and winter savory have significantly lowered their production. The results of the Griess assay suggested that lavender, motherwort, peppermint, basil, rosemary, sage, winter savory, ironwort, and thyme have significantly increased the production of NO. Furthermore, Comet assay results pointed out that motherwort, peppermint, basil, oregano, marjoram, winter savory, ironwort, wild thyme, thyme, and mountain germander possess genotoxic potential towards HCT-116 cells, while only basil had genotoxic activity statistically similar to etoposide. The obtained results are in accordance with our previous findings, which indicated that these extracts have antigenotoxic and genoprotective activities towards normal cells. Finally, it can be concluded that these traditionally valued plants might act as potent antitumor agents by modulating the proliferation and production of ROS and NO by cancer cells, as well as by expressing significant genotoxic properties towards cancer cells.