Ligustilide alleviates podocyte injury via suppressing the SIRT1/NF-κB signaling pathways in rats with diabetic nephropathy

Background: Diabetic nephropathy (DN) is one of the common chronic microvascular complications of diabetes, and podocyte injury and dysfunction are strictly related to the pathogenesis of DN. Studies have shown that ligustilide (LIG) has anti-inflammatory, antioxidant, and anti-apoptotic activities. This study was designed to investigate the therapeutic effect of LIG in DN rats and their mechanisms. Methods: DN rat models (n=10) were induced by streptozotocin (STZ) combined with a high-fat diet. Rats in the LIG group were intragastrically administered with LIG daily for eight weeks, and animals in the positive control group were treated with Losartan potassium. The body weight and blood glucose were checked weekly during the treatment. The pathological changes of kidney tissue were observed with hematoxylin and eosin (HE) staining. Blood lipid profiles and renal function-related markers, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), blood urea nitrogen (BUN), and serum creatinine (Scr) were monitored using a biochemical analyzer. The protein expression of nephrin was determined by immunohistochemistry and Western blotting. Finally, Western blot was used to determine the protein expression of Sirtuin 1 (SIRT1) and nuclear factor-kappa B (NF-kappa B). Results: Compared with the healthy control group, rats in the DN group have slower weight gain, increased blood sugar level, renal lesions, and impaired renal function, along with decreased nephrin expression, abnormally activated NF-kappa B, and inhibited SIRT1 protein expression. All the above conditions were improved after intervention with either losartan potassium or LIG. Conclusions: LIG attenuates podocyte injury by regulating the SIRT1/NF-kappa B signaling pathway and thereby exerts its protective effect on renal function in DN rats.