Figure 1
Structure of N-alkyl quaternary quinuclidines used in this study
Figure 2
Experimental design for testing quinuclidine derivative and fisetin effects on human erythrocytes
Figure 3
Haemolysis (%) of erythrocytes A) after 24 h exposure to selected Q(N)OHs (0.1– 100 μmol/L) and fisetin (100 μmol/L) and B) after 4 h exposure to Q(N)OHs in determined IC25, IC50, or IC75 compared to untreated control (Triton X-100 was used as positive control)
Table 1
IC25, IC50, IC75 values determined from haemolysis curves after 24-hour erythrocyte exposure to Q(N)OHs
| Inhibitory concentrations | QOH-C14 | QOH-C16 | QNOH-C14 | QNOH-C16 |
|---|---|---|---|---|
| IC25 (μmol/L) | 13 | 10 | 13 | 23 |
| IC50 (μmol/L) | 16 | 12 | 23 | 29 |
| IC75 (μmol/L) | 20 | 14.5 | 40 | 37 |
Figure 4
Haemolysis (%) of erythrocytes after 24 h exposure to tested Q(N)OHs-C14 and C16 (in corresponding IC25, IC50, and IC75) in combination with fisetin (Fis; 0, 1, 10 or 100 μmol/L). Untreated control received only culture medium. Triton X-100 (4 %, TX) was used as positive control. Values are presented means ± SD. & – p<0.05; # – p<0.01; $ – p<0.001; * – p<0.0001 compared to untreated control (ANOVA followed by Dunnett's test)
Figure 5
Reactive oxygen species production in erythrocytes exposed to IC25, IC50, or IC75 of Q(N)OH derivatives or their combinations with (1, 10, or 100 μmol/L fisetin over 4 h. Control received only culture medium (white column). Tert-butyl hydrogen peroxide (100 μmol/L, red column) was used as positive control. & – p<0.05; # – p<0.01; $ – p<0.001; * – p<0.0001 compared to untreated control (ANOVA followed by Dunnett's test)
Figure 6
Glutathione (GSH) levels in erythrocytes exposed to IC25, IC50, or IC75 of Q(N)OH derivatives for 4 h. Control received only culture medium (white column). Tert-butyl hydrogen peroxide (100 μmol/L, red column) was used as positive control. * p<0.0001 compared to untreated control (ANOVA followed by Dunnett's test)
Figure 7
Superoxide dismutase (SOD) activity in erythrocytes exposed to IC25, IC50, or IC75 of Q(N)OH derivatives or their combinations with 10 μmol/L fisetin for 4 h. Control received only culture medium (white column). Tert-butyl hydrogen peroxide (100 μmol/L, red column) was used as positive control. & – p<0.05; # – p<0.01; $ – p<0.001; * – p<0.0001 compared to untreated control (ANOVA followed by Dunnett's test)