Phytochemical analysis, antioxidant, antibacterial and cytotoxic activity of different plant organs of Eryngium serbicum L.

Plants from genus Eryngium are widely used in traditional medicine for treatment of various disorders. In this study, in vitro antioxidant, antibacterial and cytotoxic activity, as well as composition of bioactive constituents of the methanol extracts (flowers, leaves, stems and roots) of Eryngium serbicum are reported for the first time. By using LC-ESI-MS/MS, 22 bioactive compounds present in extracts were quantified. The most abundant compound observed in flower and stem extracts was chlorogenic acid (2704.23 mu g/g and 1813.13 mu g/g, respectively), while the most dominant compound in leaf and root extracts was rosmarinic acid (869.65 mu g/g and 6467.69 mu g/g, respectively). All examined extracts showed high contents of total phenolic compounds (expressed as mg GAE/g), flavonoids (expressed as mg RUE/g), flavonols (expressed as mg RUE/g) and total phenolic acids (expressed as mg CAE/g). Also, a notable antioxidant power of extracts was observed from the results of DPPH free-radical scavenging activity (as IC50, mu g/mL), ARTS radical-cation scavenging activity (as IC50, mu g/mL), reducing power activity (as RP50, mu g/mL), as well as results of inhibitory activity toward lipid peroxidation (as IC50, mu g/mL). With the exceptions of low activity of stem extract toward Enterococcus faecalis and Staphylococcus epidermidis, as well as leaf and stem extracts against Escherichia coli, all other examined extracts showed a notable activity toward test bacteria (MIC range: 15.6 mu g/mL to 125 mu g/mL). Crude E. serbicum extracts from flowers, leaves and stems showed selective cytotoxic activity towards tested cell lines, without effects on normal MRC-5 cells. After 72 h of exposure, all examined extracts were exerting a strong effect against colon (HCT-116, SW-480) and breast (MDA-MB-231) cancer cell lines. Flow cytometric analysis showed that examined extracts induced primary apoptotic type of cell death and cell cycle arrest. Due to strong activity, further in vivo studies and exact mechanism of action could be useful in designing new antibacterial and anticancer therapeutic agents.