Hydrophobic NADES-Derived Pumpkin Carotenoid Extract Attenuates Oxidative Stress and Mitochondrial Dysfunction in a Rat Model of Doxorubicin-Induced Cardiotoxicity

Abstract

Background/Objectives: Doxorubicin-induced cardiotoxicity (DIC) is driven by oxidative stress and impaired oxidative phosphorylation (OXPHOS). Antioxidant properties of carotenoids in vivo depend on extraction, while their direct role in mitigating DIC remains undetermined. This study evaluated the cardioprotective potential of natural deep eutectic solvents (NADES)-derived pumpkin carotenoid extract in a rat model of DIC. Methods: NADES-derived pumpkin pulp extract was characterized by spectrophotometry and HPLC-DAD. Wistar rats (n = 30) were assigned to six groups: C (control), N (NADES, 1 mL, p.o.), P (extract, 900 µg/kg body weight/day of total carotenoids, p.o.), D (doxorubicin, four i.p. doses, 2 mg/kg), ND (NADES/doxorubicin) and PD (900 µg/kg body weight/day of total carotenoids/doxorubicin). The activity of antioxidant enzymes and mitochondrial respiration in saponin-permeabilized left ventricular fibers using a Clark-type oxygen electrode) was measured. Results: Compared to control, cardiac antioxidant enzyme activities, mitochondrial respiration in complex I–linked respiration, ADP-supported OXPHOS, maximal respiratory capacity, and complex II and IV-linked respiration were significantly impaired by doxorubicin and unaltered by NADES. Co-administration of the extract significantly improved antioxidant enzyme activities (GSH-Px: D group 45 vs. PD group 95 nmol/mg proteins; GR: D group 95 vs. PD group 145 nmol/mg proteins; GST: D group 15 vs. PD group 22 nmol/mg proteins; SOD: D group 9 vs. PD group 17 U/mg proteins) and attenuated mitochondrial respiratory dysfunction compared with doxorubicin-treated group, indicating partial preservation of electron transport system capacity. Conclusions: Despite limitations of the study (single sex, single dose), results suggest NADES-based carotenoid extracts have cardioprotective properties in DIC by enhancing antioxidant defenses and supporting mitochondrial respiration.