Salidroside attenuates LPS-induced kidney injury through activation of SIRT1/Nrf2 pathway

Background Salidroside (SAL) is an anti-inflammatory, antioxidant, anticancer, neuroprotective, and renal protective active ingredient extracted from the Chinese herb. Rhodiola Rosea. However, the role of SAL in kidney injury has not yet been elucidated. The study investigates SAL's protective effect and mechanism in lipopolysaccharide (LPS)-induced kidney injury. Methods Male C57BL/6 wild-type mice (6-8 weeks old) were intraperitoneally injected with 10 mg/kg LPS for 24 h and SAL (50 mg/kg) 2 h before the LPS injection. Biochemical and TUNNEL staining assay analyses were carried out to assess kidney injury. The Elisa assay analyzed the mRNA expression of NGAL and KIM-1. RT-qPCR and Western blotting measured the mRNA and protein expression of HO-1, NQO1, Beclin1, P62, SIRT1, Nrf2, and PNCA, respectively. Results Our study found that mice co-treated with SAL had significantly reduced blood urea nitrogen (BUN), serum creatinine (Scr), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) levels in serum of LPS-induced mice. SAL cotreatment potentially decreased the apoptosis rate of kidney tissue and podocytes induced by LPS. SAL significantly reduced the content of malondialdehyde (MDA) and increased superoxide dismutase (SOD) in LPS-treated mice. Autophagy-related proteins Beclin-1 increased but decreased P62 protein expression by cotreatment of SAL in LPS-injected mice. SAL enhanced the Sirtuin 1 (SIRT1) and nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression in LPS-induced kidney tissues. Conclusion Our results speculate that SAL protects against LPS-induced kidney injury through activation of the SIRT1/Nrf2 pathway.