Table 1.
EC50 (half-maximum-effect concentrations), TOP (maximal effect), BOTTOM (baseline), and Hill Slope values of the paraquat (PQ) concentration—response curves, with (PQ + OXs) or without (PQ) simultaneous exposure to the six tested oxygenated xanthones, OX 1–6 (20.0 µM).
| PQ | PQ + OX1 | PQ + OX2 | PQ + OX3 | PQ + OX4 | PQ + OX5 | PQ + OX6 | |
|---|---|---|---|---|---|---|---|
| EC50 [half-maximum-effect concentrations, µM (95% CI)] |
982.4 (912.4–1058) |
1124 (900.8–1402) |
1153 * (1013–1313) |
1291 ** (1050–1587) |
1188 * (1027–1375) |
1217 ** (1046–1417) |
943.0 (757.2–1174) |
| Top (maximal cell death, % control) |
96.65 | ~100.0 | 88.76 | 96.80 | 96.48 | 94.89 | 94.51 |
| Bottom (baseline, % control) |
2.008 | 0.9805 | 1.236 | 0.01597 | 0.2445 | −1.129 | −0.2018 |
| Hill slope | 1.694 | 1.524 | 2.178 | 1.674 | 1.955 | 2.088 | 1.618 |
| Curve p value (Comparison between the fitted curves) |
- | 0.2139 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | 0.6121 |
Concentration—response curves were fitted using least squares as the fitting method and the comparisons between PQ and PQ + OX 1-6 curves were made using the extra sum-of-squares F test. In all cases, p values < 0.05 were considered significant (* p < 0.05; ** p < 0.01 for PQ vs. PQ + OXs). 95% CI–95% Confidence Intervals. Bold is used when significant exists.