Strobilanthes sarcorrhiza root phenolic extract prevent diabetic nephropathy in mice by regulating NF-κB/IL-1β signaling and glycerophospholipid metabolism

Strobilanthes sarcorrhiza, a folk medicine from China, is known to treat kidney deficiency and lumbago. However, its protective effects and mechanisms against diabetic nephropathy (DN) remain unclear. This study aimed to investigate the effects and mechanisms of Strobilanthes sarcorrhiza root phenolic extract (CTS) on streptozotocin (STZ)-induced DN in mice. Firstly, the constituents in CTS were characterized by UPLC-QTOF-MS. Thirty-three constituents were identified, including 12 phenylethanoid glycosides and their derivatives, 14 phenylpropanoid glycosides derivatives, 6 polyphenols derivatives, and 1 other constituent. Then, utilizing the identified constituents of CTS, network pharmacology was used to anticipate potential pathways against DN. Thirty-two out of thirty-three constituents showed anti-DN activity; their mechanism of action was significantly linked to tumor-, glycosylation-, metabolism-related pathways, etc. Furthermore, the effectiveness of CTS against DN and its in vivo mechanism was assessed by combining immunohistochemistry, untargeted metabolomics, biochemical evaluation, and histopathological examination. The findings showed that CTS improved blood glucose and lipid levels in diabetic mice, reduced serum levels of ALT, CREA, UREA, IL-1β, and IL-17, decreased pathological damage and fibrosis in kidney tissue, and lowered the protein expression of VEGF, Laminin, TNF-α, and NF-κB in kidney tissue. Metabolomics results indicated that CTS alleviated DN mainly by regulating glycerophospholipid metabolism. To the best of our knowledge, this study is the first to report that Strobilanthes sarcorrhiza attenuates DN, potentially through the inhibition of the NF-κB pathway, leading to a reduction in the inflammatory response and fibrosis of renal tissue. These findings suggest that Strobilanthes sarcorrhiza could be a promising therapeutic agent for DN.