Protective effect of astaxanthin against contrast-induced acute kidney injury via SIRT1-p53 pathway in rats.

PURPOSE

The present study was designed to further investigate the protective effect of astaxanthin (AST) on contrast-induced acute kidney injury (CI-AKI) in rats and the relationship between SIRT1-p53 pathway and astaxanthin.

METHODS

40 adult male Sprague Dawley (SD) rats were randomly divided into five groups (n = 8/group): control (CON), normal rats treated with AST (AST), CM-treated (CM), CM rats treated with isoform of nitric oxide synthase (iNOS) inhibitor (iNOS + CM), and CM rats treated with AST (AST + CM). Serum creatinine (Scr) and blood urea nitrogen (BUN) values were measured at 72 h following the procedure. Hematoxylin and eosin (H-E) staining was used to observe the pathologic changes of kidney. Tunel staining was used to test apoptosis of kidney tubules. Oxidative stress, SIRT1 activity, nitric oxide (NO), and 3-nitrotyrosine (3-NT) content were individually measured with the commercial available kits.

RESULTS

Compared with the CON group, Scr and BUN levels significantly increased in the CM group (P < 0.05), and the values in two pre-treatment groups (iNOS + CM and AST + CM) had significantly decreased (P < 0.05). H-E and Tunel staining had shown that renal tubular injury was severe in CM group. The renal injury score and apoptosis index in the two pre-treatment groups also decreased (P < 0.05). The present study showed that in CM group the levels of oxidative stress indicators significantly increased, and the activities of antioxidant stress indicators significantly decreased. These indicators in two pre-treatment groups significantly improved (P < 0.05). In the CM group the expression levels of SITR1 significantly increased, and the ac-p53/p53 significantly increased (P < 0.05). Compared with the CM group, in AST + CM group the expression levels of SIRT1 increased, the expression levels of p53 and ac-p53/p53 decreased (P < 0.05).The levels of NO and 3-NT in CM group significantly increased (P < 0.05). Compared the CM group, the levels in the two pre-treatment groups significantly decreased (P < 0.05).

CONCLUSIONS

Astaxanthin has a protective effect on CI-AKI, the mechanism may be related to the SIRT1-p53 pathway. Astaxanthin can reduce the content of NO and 3-NT in renal tissue of CI-AKI, and alleviate the renal injury induced by contrast agents.