RedRif’s effect on paraquat-induced cytotoxicity.

<p>The NR uptake assay was performed to assess RedRif’s effect in PQ cytotoxicity in a <b>a</b>) simultaneous exposure to RedRif and PQ for 48 h – study of P-gp activation effect, and <b>b</b>) 24 h, <b>c</b>) 48 h and <b>d</b>) 72 h of exposure to RedRif before exposure to PQ – study of P-gp induction effect. RedRif’s protective effect against PQ-induced cytotoxicity was more significant in the simultaneous exposure assay. Two-way ANOVA was performed to estimate the differences between control (black bars) and RedRif-treated (grey bars) cells for each PQ concentration. Concentration–response curves shown as inserts were fitted using least squares as the fitting method, and the comparisons between the curves obtained in the presence and the absence of RedRif (bottom, top and EC₅₀) were made using the extra sum-of-squares F test. At least 3 independent experiments were performed in triplicate. **p<0.01 and ***p<0.001 and ****p<0.0001 for differences between control and RedRif-treated cells for each PQ concentration and for differences between the curves <i>vs</i>. control; $p<0.05 and $ $p<0.01 for differences in EC₅₀<i>vs</i>. control.