Royal jelly attenuates cadmium-induced nephrotoxicity in male mice

Cadmium exposure induces nephrotoxicity by mediating oxidative stress, inflammation, and apoptosis. The purpose of this study was to examine the protective effect of royal jelly on Cd-induced nephrotoxicity. Adult male mice were distributed randomly into 4 clusters: untreated, royal jelly-treated (85 mg/kg, oral), CdCl₂-treated (6.5 mg/kg, intraperitoneal), and pretreated with royal jelly (85 mg/kg) 2 h before CdCl₂ injection (6.5 mg/kg, intraperitoneal) for seven consecutive days. Cd concentration in the renal tissue and absolute kidney weight of the Cd-treated mice were significantly higher than those of control group. The levels of kidney function markers, kidney injury molecules-1 (KIM-1), metallothionein, lipid peroxidation, nitric oxide, tumor necrosis factor-α, interleukin-1β, and the apoptosis regulators Bax and caspases-3 also increased significantly in the renal tissue of Cd-treated mice, whereas the levels of glutathione, antioxidant enzyme activities, and the apoptosis inhibitor Bcl-2 were significantly reduced in the renal tissue of Cd-treated group. Histopathological studies showed vacuolation and congested glomeruli in the kidney tissue of Cd-treated mice. However, all aforementioned Cd-induced changes were attenuated by pretreatment with royal jelly. We therefore concluded that royal jelly attenuated Cd-induced nephrotoxicity and it is suggested that this nephroprotective effect could be linked to its ability to promote the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant responsive element (ARE) pathway.