Curcumin plays a protective role against septic acute kidney injury by regulating the TLR9 signaling pathway

BACKGROUND: This study aims to evaluate the inhibitory effect of curcumin (Cur) on the progression of septic acute kidney injury (SAKI), in order to improve the survival rate in this patient population. METHODS: Acute kidney injury (AKI) was induced by cecal ligation perforation (CLP) in Sprague-Dawley (SD) rats. Using this AKI animal model, the survival rate of the rats was evaluated at different time points after Cur treatment to explore whether Cur can improve survival in an animal model of AKI. The expression levels of inflammatory factors (NF-κB, TNF-α, and IL-10), organ injury markers [urea nitrogen (UN), creatinine (Cr), alanine aminotransferase (ALT), aspartate aminotransferase (AST), amylase, creatine kinase (CK), and lactate dehydrogenase (LDH)], and disease progression markers [neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and cystatin-C (CysC)] were determined using an enzyme-linked immunosorbent assay (ELISA). RESULTS: The serum levels of UN, Cr, NF-κB, ALT, AST, amylase, CK, LDH, inflammatory factors TNF-α and IL-10, and markers of early diagnosis of SAKI (NGAL, CysC, KIM-1) were significantly lower in the curcumin group than those in the placebo group (P<0.05). In addition, serum levels of TLR9 and its downstream molecules MyD88, IRF5, and IRF7 in the curcumin group were significantly lower than those in the placebo group (P<0.05). The application of TLR9-specific inhibitors to experimental rats led to similar results as those obtained in the curcumin group, whose detection indexes were significantly lower than those in the placebo treatment group (P<0.05). CONCLUSIONS: Given the excellent performance of Cur in anti-tumor, anti-oxidation, anti-inflammatory, and other clinical trials, it is very likely to be further developed as a potential drug for the clinical treatment of AKI.