Protective mechanisms of Leontopodium leontopodioides extracts on lipopolysaccharide-induced acute kidney injury via the NF-κB/NLRP3 pathway

Sepsis-induced uncontrolled systemic inflammatory response syndrome(SIRS)is a critical cause of multiple organ failure.Acute kidney injury(AKI)is one of the most serious complications associated with an extremely high mortality rate in SIRS,and it lacked simple,safe,and effective treatment strategies.Leontopodium leontopodioides(Willd.)Beauv(LLB)is commonly used in traditional Chinese medicine for the treatment of acute and chronic nephritis.However,it remains unclear whether lipopolysaccharide(LPS)affects LPS-induced AKI.To identify the molecular mechanisms of LLB in LPS-induced HK-2 cells and mice,LLB was prepared by extraction with 70%methanol,while a lipopolysaccharide(LPS)-induced HK-2 cell model and an AKI model were established in this study.Renal histopathology staining was performed to observe the morphology changes.The cell supernatant and kidney tissues were collected for determining the levels of inflammatory factors and protein expression by ELISA,immunofluorescence,and Western blot.The results indicated that LLB significantly reduced the expression of IL-6 and TNF-αin LPS-induced HK-2 cells,as well as the secretion of IL-6,TNF-α,and IL-1βin the supernatant.The same results were observed in LPS-induced AKI serum.Further studies revealed that LLB remarkably improved oxidative stress and apoptosis based on the content of MDA,SOD,and CAT in serum and TUNEL staining results.Notably,LLB significantly reduced the mortality due to LPS infection.Renal histopathology staining results supported these results.Furthermore,immunofluorescence and Western blot results confirmed that LLB significantly reduced the expression of the protein related to the NF-κB signaling pathway and NLRP3,ASC,and Caspase-1 which were significantly increased through LPS stimulation.These findings clearly demonstrated the potential use of LLB in the treatment of AKI and the crucial role of the NF-κB/NLRP3 pathway in the process through which LLB attenuates AKI induced by LPS.

Antagonistic effects of extracts from Artemisia rupetris L. and Leontopodium leontopodioides to CC chemokine receptor 2b(CCR2b)

The present study was designed to establish a suitable assay to explore CCR2 b receptor antagonists from the natural products of Artemisia rupetris and Leontopodium leontopodioides. An aequorin assay was developed as a cell-based assay suitable for 384-well microplate and used for screening CCR2 b receptor antagonists from natural products. Through establishing suitable conditions, the assay was shown to be suitable for screening of CCR2 b receptor antagonists. Seven compounds were identified in preliminary screening. Five of them showed evident dose-response relationship in secondary screening. The structure–activity relationship study suggested that 7-position hydroxyl group of flavonoids was necessary, a polar group should be introduced on the 3-position, and the substituents on 2-position benzene ring of flavonoids have little influence on the potentency of the inhibition activity on CCR2 b receptor. The ortho-position dihydroxyl structure in quinic acid compounds may be important. In conclusion, Compounds HR-1, 5, 7, and AR-20, 35 showed activity as antagonist of CCR2 b receptor, which shed lights on the development of novel drugs as CCR2 b receptor antagonists for preventing inflammation related diseases.