Eriodictyol attenuates doxorubicin-induced nephropathy by activating the AMPK/Nrf2 signalling pathway

Doxorubicin (DOX), an anthracycline chemotherapy, plays a prominent role in the treatment of various cancers. Unfortunately, its nephrotoxic effects limit its dosing and expose cancer survivors to increased morbidity and mortality. This study examined the nephroprotective effects of eriodictyol, a natural polyphenolic flavanone, in DOX-treated rats and the molecular pathways involved. Forty adult rats were divided into five groups (8/group): Control; eriodictyol (20 mg/kg/day); DOX (2.5 mg/kg, twice/week); DOX + Eriodictyol; and DOX + Eriodictyol + Compound C (CC), an AMPK inhibitor (0.2 mg/kg/day). Experiments continued for 21 days. Eriodictyol administration in DOX-treated rats reduced their fasting glucose levels and increased food intake, final body weight, and kidney weight, improved kidney function, prevented glomerular and tubular damage, and reduced collagen deposition and renal TGF-β1 mRNA levels. Furthermore, eriodictyol reduced their renal levels of Bax, caspase-3, and cytochrome-c; and enhanced the levels of Bcl2. Noticeably, in the kidneys of both controls and DOX-treated rats, eriodictyol increased levels of phosphorylated-AMPK(Thr172) but not AMPK mRNA nor protein levels. Also, in the same two groups, eriodictyol increased mRNA and nuclear Nrf2 levels, and levels of glutathione, superoxide dismutase, catalase, and hemeoxygenase-1, but reduced the levels of malonaldehyde, TNF-α, and mRNA, total, and nuclear levels of NF-κB. All the detected nephroprotective effects and improvements in the levels of markers of oxidation and inflammation were prevented by coadministration of CC. In conclusion, the coadministration of eriodictyol and DOX alleviates DOX-induced renal damage. In renal tissues, eriodictyol is an AMPK activator and its nephroprotective antioxidant and anti-inflammatory effects are AMPK-dependent.