[Mechanism of Qitu Erzhi Decoction against chemotherapy-induced myelosuppression based on network pharmacology and experimental validation].

To investigate the mechanism of Qitu Erzhi Decoction(QTEZ) in ameliorating chemotherapy-induced myelosuppression and the focus of its decomposed formulae on the effects of hematopoietic cells of the three lineages, respectively. Ultra performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS) was used to identify the components of QTEZ intestinal absorption liquid and obtain the target sites, which were intersected with chemotherapy-induced myelosuppression targets collected from several databases, including OMIM, and an interaction network was established based on network pharmacology for Gene Ontology(GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis. Hematopoietic stem cells of mice were taken after intraperitoneal injection of 5-fluorouracil for myelosuppression modeling and randomly divided into the model group, Qitu Erzhi group, Astragali Radix-Angelicae Sinensis Radix group, Ligustri Lucidi Fructus-Ecliptae Herba group, Psoraleae Fructus-Cuscutae Semen group, and positive drug group, which were given the corresponding traditional Chinese medicine intestinal absorption liquid and the positive drug granulocyte colony-stimulating factor, respectively. The normal hematopoietic stem cells were taken as the control group and were given the intervention of normal saline. The proliferation of hematopoietic progenitor cells of three lineages was observed by flow cytometry, and the cell cycle and colony formation assay were observed. Western blot was used to verify the effect of QTEZ on the pathway proteins including phosphoinositide 3-kinase(PI3K), phosphorylated PI3K(p-PI3K), protein kinase B(AKT), and phosphorylated AKT(p-AKT). RT-qPCR and Western blot were used to detect the effects of QTEZ on cell cycle-related targets such as CDK inhibitor 1(P21), cyclin D1(CCND1), and cyclin-dependent kinase 4(CDK4). The results showed that a total of 158 components were identified by QTEZ, and 375 component and disease intersecting targets were obtained, 21 core components and 40 core targets were obtained after constructing the network, and GO and KEGG enrichment showed signaling pathways such as PI3K/AKT. QTEZ and its decomposed formulae could promote the 5-fluorouracil-blocked cell cycle to resume operation, and all of them had different degrees of restoration effects on the set of colonies, among which QTEZ had the best restoration effect, and the Astragali Radix-Angelicae Sinensis Radix group had a focused effect on colony forming unit-erythrocyte. Western blot results indicated that there was no significant difference in the expression levels of pathway proteins among the groups. RT-qPCR and Western blot results showed that QTEZ could down-regulate P21 and up-regulate the protein and mRNA expression of CDK4 and CCND1. In conclusion, QTEZ and its decomposed formulas can exert a protective effect on hematopoietic stem cells with 5-fluorouracil-induced myelosuppression by promoting the normal operation of the cell cycle and colony formation, and the mechanism may be related to the down-regulation of the cell cycle-related targets of P21 and the up-regulation of CDK4 and CCND1. In addition, Astragali Radix-Angelicae Sinensis Radix can have a targeted protective effect on erythrocytes.