## 3 Results
\({}^{\mathrm{a}}\) statistically significant differences vs. V1 phase, \(p\) < 0.05. HPLC analysis revealed that the highest amounts of identified compounds and their anti-radical activity are determined in the methanolic extracts of collected raw material at the F2 phase. Presented HPLC chromatogram (Figure 4) shows that rutin (peak number 4) and rosmarinic acid (peak number 5) are the predominant compounds. Although the quantities of identified compounds are similar, post-column DPPH radical scavenging profile shows that radical scavenging activity of rosmarinic acid is three times higher than that of rutin. Post-column DPPH assay revealed that radical scavenging activity of _trans_-synaptic acid, _trans_-p-coumaric acid and hesperetin is significantly lower. The strong correlation (\(r^{2}\) = 0.9759) between content of rosmarinic acid and total radical scavenging activity of the extract was determined earlier [34]. Rosmarinic acid is the strongest antioxidant in a mixture, and its contribution to the total radical scavenging activity is the highest. Correlation coefficients calculated for other compounds were lower, but they are also considered to be strong, as for example _trans_-synaptic acid--\(r^{2}\) = 0.772, _trans_-p-coumaric acid \(r^{2}\) = 0.832, hesperetin \(r^{2}\) = 0.787. The cytotoxicity of alcoholic extracts from _S. hotensis_ L. was tested against human melanocytes and human malignant melanoma cells. Cells viability was assessed by their ability to reduce MTT to formazan dye after 24-h exposure of cells to _S. hotensis_ L. extract at various concentrations ranging from 12.5 to 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL. A concentration-dependent inhibitory effect of the extracts on the viability of melanocytes and melanoma cancer cells was observed. Cytotoxicity was considered whenever the percentage of cell survival was less than 70%. The IC50 for each of extracts were estimated as IC50V1 = 1.250 mg/mL, IC50V2 = 8.535 mg/mL, IC50F1 = 325 \(\mathrm{\SIUnitSymbolMicro g}\)/mL, IC50F2 = 160 \(\mathrm{\SIUnitSymbolMicro g}\)/mL, IC50F3 = 25 \(\mathrm{\SIUnitSymbolMicro g}\)/mL in the case of melanocytes and IC50V1 = 285 \(\mathrm{\SIUnitSymbolMicro g}\)/mL, IC50V2 = 270 \(\mathrm{\SIUnitSymbolMicro g}\)/mL, IC50F1 = 195 \(\mathrm{\SIUnitSymbolMicro g}\)/mL, IC50F2 = 45 \(\mathrm{\SIUnitSymbolMicro g}\)/mL, IC50F3 = 140 \(\mathrm{\SIUnitSymbolMicro g}\)/mL for melanoma cells. Extracts V1, V2, and F1 at the concentrations used practically did not affect melanocytes survival, while extract F2 gradually reduced melanocytes survival to about 70% (for a concentration of 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL). In contrast, extract F3 already at a concentration of 12.5 \(\mathrm{\SIUnitSymbolMicro g}\)/mL reduced the survival of melanocytes to 60%, and at higher concentrations reduced it to about 50%. In contrast, V1, V2, and F1 extracts were also not toxic to melanoma cells, while F2 extract showed cytotoxicity from 50 \(\mathrm{\SIUnitSymbolMicro g}\)/mL, and F3 from 12.5 \(\mathrm{\SIUnitSymbolMicro g}\)/mL (Figure 5). Figure 4: Chromatographic profile of _Satureja hotensis_ L. raw material methanolic extract during the F2 phase. 1—_trans_-sinapic acid 19.44 min., 2—_trans_-p-coumaric acid 23.27 min., 3—hesperetin 23.83 min., 4—rutin 24.73 min., 5—rosmarinic acid 25.84 min. None of the _S. hotensis_ L. extracts up to a concentration of 50 ug/mL increased lipid peroxidation, estimated by MDA, in both melanocytes and melanoma cells (Figure 6). Only at a concentration of 100 ug/mL extracts of phases F2 and F3 increased peroxidation in melanocytes and extracts of F1-F3 in melanoma cells. Whereas UVB radiation increased lipid peroxidation in both melanocytes and melanoma cells, additionally causing greater vulnerability of cells to extracts, which was especially manifested in the case of melanoma cells.