Anti-inflammatory effects of saxagliptin and vildagliptin against doxorubicin-induced nephrotoxicity in rats: attenuation of NLRP3 inflammasome up-regulation and tubulo-interstitial injury

BACKGROUND AND PURPOSE: The clinical use of the chemotherapeutic drug, doxorubicin (DXR), is significantly limited by its extensive multi-organ toxicity. Dipeptidyl peptidase-4 (DPP4) is over-expressed in oxidative stress, inflammation and apoptosis. DPP4 inhibitors have proven pleiotropic effects. The study investigates the protective effects of some DDP4 inhibitors; namely, saxagliptin (SAX) and vildagliptin (VIL) against DXR-induced nephrotoxicity in rats. EXPERIMENTAL APPROACH: Forty rats were divided into 4 groups. Group I served as normal control. Nephrotoxicity was induced in the remaining 3 groups by single-DXR injection (15 mg/kg, i.p.). Groups III and IV administered oral SAX (10 mg/kg) and VIL (10 mg/kg) for 2 weeks. FINDINGS/RESULTS: DXR-control rats showed deteriorated renal functions, elevated renal inflammatory parameters (tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and inducible nitric oxide synthase (iNOS)), up-regulated nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome and significant tubulointerstitial injury manifested by elevated neutrophil gelatinase-associated lipocalin concentration and distorted renal histopathological pictures. Immunohistochemical studies showed increased iNOS and Bax positivity in renal tissues of DXR-control rats. Treatment with SAX and VIL significantly attenuated DXR-induced nephrotoxicity via alleviation of all the above-mentioned parameters when compared to DXR-control rats. CONCLUSION AND IMPLICATIONS: The study elucidated the possible mechanisms beyond DXR-induced nephrotoxicity to be through inflammation plus tubulointerstitial injury. DXR nephrotoxicity has been linked to TNF-α, IL-1β, and NLRP3 inflammasome up-regulation and iNOS expression. The protective role of SAX and VIL in mitigating the tubular injury and inflammatory effects of DXR on renal tissues has been tested and proved.