Hydrangea paniculata coumarins alleviate adriamycin-induced renal lipotoxicity through activating AMPK and inhibiting C/EBPß.

ETHNOPHARMACOLOGICAL RELEVANCE: Throughout Chinese history, Hydrangea paniculata Siebold has been utilized as a traditional medicinal herb to treat a variety of ailments associated to inflammation. In a number of immune-mediated kidney disorders, total coumarins extracted from Hydrangea paniculata (HP) have demonstrated a renal protective effect. AIM OF THE STUDY: To investigate renal beneficial effect of HP on experimental Adriamycin nephropathy (AN), and further clarify whether reversing lipid metabolism abnormalities by HP contributes to its renoprotective effect and find out the underlying critical pathways. MATERIALS AND METHODS: After establishment of rat AN model, HP was orally administrated for 6 weeks. Biochemical indicators related to kidney injury were determined. mRNAs sequencing using kidney tissues were performed to clarify the underlying mechanism. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis, western blot, molecular docking, and drug affinity responsive target stability (DARTS) assay was carried out to further explore and confirm pivotal molecular pathways and possible target by which HP and 7-hydroxylcoumarin (7-HC) played their renal protection effect via modulating lipid metabolism. RESULTS: HP could significantly improve renal function, and restore renal tubular abnormal lipid metabolism and interstitial fibrosis in AN. In vitro study demonstrated that HP and its main metabolite 7-HC could reduce ADR-induced intracellular lipid deposition and fibrosis characteristics in renal tubular cells. Mechanically, HP and 7-HC can activate AMP-activated protein kinase (AMPK) via direct interaction, which contributes to its lipid metabolism modulation effect. Moreover, HP and 7-HC can inhibit fibrosis by inhibiting CCAAT/enhancer binding protein beta (C/EBPß) expression in renal tubular cells. Normalization of lipid metabolism by HP and 7-HC further provided protection of mitochondrial structure integrity and inhibited the nuclear factor kappa-B (NF-κB) pathway. Long-term toxicity using beagle dogs proved the safety of HP after one-month administration. CONCLUSION: Coumarin derivates from HP alleviate adriamycin-induced lipotoxicity and fibrosis in kidney through activating AMPK and inhibiting C/EBPß.

Esculetin alleviates murine lupus nephritis by inhibiting complement activation and enhancing Nrf2 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Esculetin is a bioactive compound of medicinal herb Hydrangea paniculata, and has showed anti-oxidation and anti-inflammation bioactivities. Renal local oxidative stress and inflammation are import contributors for progression of lupus nephritis (LN). AIM OF THE STUDY: In the present study, the renal protective effect of esculetin against LN was evaluated using MRL/lpr mice. MATERIALS AND METHODS: MRL/lpr mice were orally administrated with esculetin (20 mg/kg and 40 mg/kg) from 10 to 20 weeks and then renal function and kidney pathology were analyzed. RESULTS: Esculetin significantly attenuated renal impairment in MRL/lpr mice by reducing blood urea nitrogen (BUN), serum creatinine (Scr) and albuminuria, and ameliorated the glomerular hypertrophy, tubular interstitial fibrosis and mononuclear cell infiltration into interstitium. mRNA microarray suggested that esculetin could significantly down-regulate complement cascade, inflammation and fibrosis pathway, and up-regulate Nrf2-related anti-oxidation genes. Most surprising finding in the current study was that esculetin could inhibit the complement activation both in classical and alternative pathway using in vitro hemolysis assay, further enzyme assay suggested that esculetin blocked the C3 convertase (C4b2a) to exert this inhibitory capability. Molecular docking predicted that esculetin had four conventional hydrogen bonds interacting with C4b2a, and CDOCKER energy is relatively lower. Luciferase reporter gene demonstrated that esculetin could activate Nrf2 signaling pathway, and further flow cytometry confirmed that anti-oxidation bioactivity of esculetin was dependent on Nrf2 activation. On the other hand, esculetin could inhibit NFκB nuclear translocation and TGFß-smad3 profibrosis pathway. CONCLUSION: Esculetin shows beneficial effect on LN progression, and it may be a good natural leading compound for design of chemical compounds to treat LN.

Total coumarin derivates from Hydrangea paniculata attenuate renal injuries in cationized-BSA induced membranous nephropathy by inhibiting complement activation and interleukin 10-mediated interstitial fibrosis.

BACKGROUND: Total coumarins extracted from Hydrangea. Paniculata, Sieb (HP) have showed renal protective effect in several experimental acute and chronic kidney diseases. PURPOSE: The aim of current study is to evaluate renal protective effect of HP against cationized-BSA (c-BSA) induced experimental membranous nephritis (MN), and further investigate its underlying mechanisms. METHODS: Rat MN model was established by intravenous injection of 5 mg c-BSA for consecutive 14 days, and after albuminuria confirmed, HP was orally administrated with 7.5, 15, 30 mg/kg for nine weeks. The renal function was measured and histopathological injuries were observed. RNA sequencing was used to analyze the altered signaling pathways in kidneys. Pharmacokinetics was performed to investigate the pharmacodynamics of major ingredients in HP and possible metabolites. Discover X platform helped to clarify the possible molecular mechanisms of major compound in HP. RESULTS: HP administration could significantly improve the renal function, and ameliorate the dyslipidemia and histopathological injuries. mRNA sequencing demonstrated that HP had anti-inflammation and anti-fibrosis effects possible through down-regulating the complement activation and PI3K-AKT pathways. Pharmacokinetics demonstrated that skimmin and 7-hydoxycoumarin (7-HC) were major compound or metabolite in plasma after oral administration. Based on Discover X platform, we confirmed that skimmin and 7-HC inhibited the   IL10 production by inflammatory macrophages through blocking PI3K-AKT and NFκB signaling pathways. Finally, we demonstrated that HP protected tubulointerstitium from complement attack by reducing the C3 self-production and auto-cleavage in tubular cells. CONCLUSIONS: HP has a renal protective effect, and its drug development may provide one alternative strategy to treat immune-mediated nephropathy.