Figure 6.

Effect of RIPS (a), digoxin (b), and RIPS fractions (c) on cell viability in chick brain slices. For the assays, brain slices were incubated with RIPS (5, 10, 20, and 40 µg/mL) and fractions RI18, RI19, RI23, and RI24 (all tested at a fixed concentration of 5 µg/mL) for 60 min prior to evaluating cell viability in the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) reduction assay. Digoxin (5, 10, 20, and 40 µg/mL), a Na⁺/K⁺-ATPase inhibitor, was included for comparison. The negative and positive controls were HEPES–saline buffer and 44 mM H₂O₂, respectively. The columns represent the mean ± S.E.M. (n = 6). * p <0.05, ** p < 0.01 and **** p < 0.0001 compared to the HEPES control.