Figure 6.

Effect of increasing the concentration of naturally occurring cyclotides on cell viability in U-87 MG cells. IC₅₀ values for cyclotides were determined using the MTT assay after incubating U-87 MG cell cultures with increasing concentrations (0.1, 1.0, 5.0, and 10 μM) or with a control of DMSO only. Panel (A): CyO3, panel (B): CyO19, panel (C): Kalata B1, panel (D): Kalata B7, and panel (E), Vitri E. U-87 cells (6000 cells per well in a 96-well plate) were treated with cyclotides, as indicated, for 72 h, then MTT measured. Cell viability was calculated as a percentage of control cultures. IC₅₀ values were calculated using the Best Fit method (See Table 1). Incubations were conducted in 96-well plates in triplicate wells (technical replicates) and as three independent incubations (biological replicates, n = 3). Data are expressed as mean ± standard error of the mean (SEM). Results are graphed in GraphPad Prism version 9 for iOS.