The Impairment of Cell Metabolism by Cardiovascular Toxicity of Doxorubicin Is Reversed by Bergamot Polyphenolic Fraction Treatment in Endothelial Cells

Figure 1. Effect of BPF on DOX-induced pAEC cytotoxicity. (A–E) Representative images of pAECs treated with DOX 0.5, 1, 10 µM (B,C,D, respectively) in the absence or presence of 100 µg/mL BPF (E). (F) Cell viability quantification: each bar represents the mean ± SD of three independent experiments. Scale bar (―) 100 µm. Different letters above the bars indicate significant differences (p < 0.05, one-way ANOVA, post hoc Tuckey comparison test) between each DOX treatment with and without BPF and the control (CTR) group.

Figure 2. Effect of 200 µg/mL BPF on the cell metabolism of pAECs treated with 10 µM DOX. The mitochondrial respiration profile was obtained from the oxygen consumption rate (OCR) in control (●, blue), 200 µg/mL BPF (■, orange), 10 µM DOX (▲, gray) and DOX plus BPF (♦, gold) treatment under basal respiration conditions and after the addition of 1.5 μM oligomycin (olig), 1.0 μM FCCP and a mixture of 0.5 μM rotenone plus antimycin A (Rot + AA). Inhibitor injections are shown as dotted lines (A). Mitochondrial parameters (basal respiration, proton leak, maximal respiration, spare respiratory capacity, ATP production) in control (█, blue), 200 µg/mL BPF (█, orange), 10 µM DOX (█, gray) and DOX plus BPF (█, gold) samples (B). Data expressed as points (A) and column charts (B) represent the means ± SD (vertical bars) from three experiments carried out on different cell preparations. Different letters indicate significant differences (p ≤ 0.05) among treatments within the same bioenergetic parameters.

Figure 3. Effect of 200 µg/mL BPF on the cell metabolism of pAECs treated with 1 µM DOX. The action of DOX on mitochondrial respiration without (A,B) and with 24 h of recovery (C,D) in the presence of BPF. The mitochondrial respiration profile was obtained from the oxygen consumption rate (OCR) in control (●, blue), 200 µg/mL BPF (■, orange), 1 µM DOX (▲, gray) and 1 µM DOX plus BPF (♦, gold) treatments under basal respiration conditions and after the addition of 1.5 μM oligomycin (olig), 1.0 μM FCCP and a mixture of 0.5 μM rotenone plus antimycin A (Rot + AA). Inhibitor injections are shown as dotted lines (A,C). Mitochondrial parameters (basal respiration, proton leak, maximal respiration, spare respiratory capacity, ATP production) in control (█, blue), 200 µg/mL BPF (█, orange), 1 µM DOX (█, gray), and 1 µM DOX plus BPF (█, gold) samples (B,D). Data expressed as points (A,C) and column charts (B,D) represent the means ± SD (vertical bars) from three experiments carried out on different cell preparations. Different letters indicate significant differences (p ≤ 0.05) among treatments within the same bioenergetic parameters.

Figure 4. Effect of 100 µg/mL BPF on cell metabolism of pAECs treated with 0.5 µM DOX. The action of DOX on mitochondrial respiration without (A,B) and with 24 h of recovery (C,D) in the presence of BPF. The mitochondrial respiration profile was obtained from the oxygen consumption rate (OCR) in control (●, blue), 100 µg/mL BPF (■, orange), 0.5 µM DOX (▲, gray), and DOX plus BPF (♦, gold) treatments under basal respiration conditions and after the addition of 1.5 μM oligomycin (olig), 1.0 μM FCCP and a mixture of 0.5 μM rotenone plus antimycin A (Rot + AA). Inhibitor injections are shown as dotted lines (A,C). Mitochondrial parameters (basal respiration, proton leak, maximal respiration, spare respiratory capacity, and ATP production) in control (█, blue), 100 µg/mL BPF (█, orange), 0.5 µM DOX (█, gray) and DOX plus BPF (█, gold) samples (B,D). Data expressed as points (A,C) and column charts (B,D) represent the means ± SD (vertical bars) from three experiments carried out on different cell preparations. Different letters indicate significant differences (p ≤ 0.05) among treatments within the same bioenergetic parameters.