Mechanism of Action of Qingrekasen Granules in Alleviating Nephrotic Syndrome Evaluated by a Multi-Omics Approach

Objectives In this study, the efficacy of and mechanism of Qingrekasen Granules (QRKSG) is evaluated by metabolomics and transcriptomics using adriamycin (ADR)-induced nephrotic syndrome (NS) in rat model.Methods The model, benazepril, and QRKSG group received a single injection of 6.5 mg/kg ADR via the tail vein of the rats. The untreated group received an equal saline injection. The administration of drugs by gavage began after completing the modeling for one week. Benazepril was given at 0.9 mg/kg/d to the benazepril group and QRKSG was given at 1.62 g/kg/d to the QRKSG group. During gavage, 24 h urine was collected weekly. After four weeks of gavage, rats were anesthetized, and we collected the serum, feces, and kidney samples. The protective effect of QRKSG on NS was assessed by the detection of proteins in the urine at 24 h and serum biochemical indexes, as well as histopathological observation, TUNEL assay, and Western Blot of kidney samples. Moreover, gas chromatography-mass spectrometry (GC-MS) metabolomics sequencing of kidney metabolites helped investigate the significant differential metabolites produced by QRKSG that are implicated in ameliorating the pathological damage to the kidneys of NS rats. Subsequently, the significant targets of QRKSG that had an impact on the action of drugs were investigated by a transcriptome sequencing analysis. The correlation between both sets was also investigated. In addition, the effect of QRKSG on the gut microbiota of NS rats was investigated. Finally, the core targets were validated by molecular docking.Results The results indicated that QRKSG possess significant renoprotective effects in NS rats by reversing the abnormal urinary protein content and serum biochemical disorders, as well as improving renal pathological damage. Multiple genes and metabolites were shown to be back-regulated after QRKSG delivery, based on further multi-omics studies. The integrated metabolomics and transcriptomics analysis showed that QRKSG alleviated NS mainly by regulating amino acid metabolic pathways. Gut microbiota analysis demonstrated that QRKSG could alleviate NS by improving gut microbiota. The molecular docking results showed good binding ability of the QRKSG active ingredient to the core target, and among them, the ingredients with the best docking effect were mainly flavonoids and phenolic acid ingredients. The combined metabolomics and transcriptomics study findings were validated through a TUNEL assay and a Western Blot analysis.Conclusion We have concluded that ADR-induced NS in rats can be treated with QRKSG. The mechanisms used by QRKSG to reduce the symptoms of NS are through the multi-component, multi-target, and multi-pathway therapeutic modulation of inflammation, oxidative stress, energy homeostasis, and apoptosis. Additionally, QRKSG could alleviate NS by regulating gut microbiota.