Effect of astaxanthin on apoptosis of rat renal tubular epithelial cells induced by iohexol.

Contrast acute kidney injury refers to acute renal failure due to the application of contrast agents. Astaxanthin, as an antioxidant, can improve early acute kidney injury in severely burned rats. However, the mechanism of astaxanthin for renal protection is still unclear. In this study, the rat renal tubular epithelial cells (NRK-52E) were treated with iohexol, astaxanthin, astaxanthin plus nicotinamide and nicotinamide. Subsequently, the nuclear morphology was observed by fluorescence staining of DAPI DNA, the apoptosis was detected by flow cytometry, the mitochondrial membrane potential was detected by JC-1 and the SIRT1, P53, Bax, Bcl-2 protein expression level was detected by Western blotting. We found that astaxanthin can reduce nuclear pyknosis and nuclear deep staining, decrease the number of apoptotic cells, up-regulate the expression of proapoptotic proteins P53 and Bax and up-regulate the expression of anti-apoptotic protein Bcl-2 by increasing SIRT1 expression level, thereby exerting protective effects on renal tubular epithelial cells. At the same time, nicotinamide has the opposite effect on the NRK-52E compared with astaxanthin. These results indicated that astaxanthin may provide a new option for the prevention of contrast-induced acute kidney injury.