Rubia cordifolia L. Dichloromethane Extract Ameliorates Contrast-Induced Acute Kidney Injury by Activating Autophagy via the LC3B/p62 Axis

Contrast-induced acute kidney injury (CIAKI) has emerged as the third most prevalent etiology of clinically acquired acute kidney injury, with a lack of specific preventive and therapeutic strategies. <i>Rubia Cordifolia</i> L. (madder root), a medicinal herb with a long-standing history and extensive clinical application, exhibits multiple pharmacological activities. This study aimed to clarify the renal protective effect of <i>Rubia cordifolia</i> L. dichloromethane extract (RCDE) on CIAKI modeling rats and investigate potential anti-apoptotic and autophagy-inducing effects molecular mechanisms. In this study, RCDE constituents were identified by UPLC-Q-TOF-MS. A CIAKI rat model was established to evaluate the nephroprotective effect of RCDE. The results showed that RCDE high-dose group significantly decreased serum SCr and BUN levels, attenuated renal histopathological damage, and modulated oxidative stress markers by decreasing MDA and CAT while increasing SOD, compared with the model group. It downregulated the expressions of Bcl-2, caspase-3 and p62, upregulated the expressions of Bax, Beclin1 and reduced the LC3B-II/LC3B-I ratio in renal tissues. Molecular docking indicates that anthraquinone compounds are probably the principal active constituents of RCDE. This study provides experimental evidence for the intervention efficacy of RCDE against CIAKI.