Fig. 3
Effect of Salvia fruticosa extract and 0.2 vol% DMSO on U2OS cell viability after 24, 48, and 72 h of incubation using MTT assay. (a) U2OS cell viability after incubation with S. fruticosa extract. The extract decreased viability in a dose and time-dependent manner. The highest decrease in cell viability (by 96%) was achieved after incubation with 150 µg/mL of the extract for 72 h. (b) S. fruticosa extract dose-response curves. The obtained dose-response curves had a negative slope, indicating a decrease in cell viability with increasing extract concentration. The obtained IC50 values were 87.75 ± 4.02 µg/mL (R² = 0.6241), 80.85 ± 10.65 µg/mL (R² = 0.6991), and 77.58 ± 3.47 µg/mL (R² = 0.9581) after 24, 48, and 72 h, respectively. (c) U2OS cell viability after incubation with 0.2 vol% DMSO, which constituted the highest concentration of the extract. No significant change in cell viability was observed over the three time points. All U2OS viability comparisons were made between the treated and untreated cells; data are representative of three experiments and significance analysis was done using two-way ANOVA followed by Tukey’s multiple comparisons test, except for the 0.2 vol% DMSO viability data analysis which was done using one-way ANOVA followed by Dunnett’s multiple comparisons test, at a 95% confidence level on GraphPad Prism 9 (**p < 0.01, ****p < 0.0001, ns = no significance). Data from dose-response curves represent the results of three experiments, and analysis was performed using nonlinear regression analysis in GraphPad Prism 9. IC50 values are shown as mean ± SD.
