Possible curative role of curcumin and silymarin against nephrotoxicity induced by gamma-rays in rats.

Curcumin (CUR) and silymarin (SLM) are powerful antioxidant and anti-inflammatory compounds with beneficial protective effects against renal diseases. The purpose of this study was to evaluate the efficacy of CUR and SLM alone or in combination on radiation (IR) induced kidney injury. The results showed that CUR and SLM alone or in combination attenuated the oxidative stress denoted by a reduction in the level of malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and advanced oxidation protein products (AOPP) along with a marked increase of glutathione GSH content and total antioxidant capacity (TAC). Additionally, a significant decrease in the level of blood urea nitrogen (BUN), creatinine, Cystatin-C (CYT-C), neutrophil gelatinase-associated lipocalin (N-GAL) and Kidney Injury Molecule-1 (Kim-1) was recorded. Moreover, the treatment resulted in a remarkable decline in the serum levels of interleukin-18(IL-18), tumor necrosis factor- alpha (TNF-α), C reactive protein (CRP), BCL2 associated X protein (Bax), Factor-related Apoptosis (FAS) and the activity of Caspase-3 associated by an increase of B-cell CLL/lymphoma 2 (Bcl2) level. The results were confirmed with the histopathological examination. Kidney of irradiated showed glomerular atrophy, massive necrotic changes of expanded tubules with hyaline cast inside some tubules and apoptotic changes were recorded in some renal tubules. While irradiated rats treated with CUR and SLM exhibited marked preservation of the cellular structure of their kidney tissue. In conclusion, the combination of CUR and SLM could be more potent than a single agent on the biochemical and histological changes of the irradiated rat renal tissue.