Abstract
   Qi-Jing-Sheng-Bai granule (QJSB) is a newly developed traditional
   Chinese medicine (TCM) formula. Clinically, it has been used for the
   treatment of leucopenia. However, its pharmacological mechanism needs
   more investigation. In this study, we firstly tested the effects of
   QJSB on leucopenia using mice induced by cyclophosphamide. Our results
   suggested that QJSB significantly raised the number of peripheral white
   blood cells, platelets and nucleated bone marrow cells. Additionally,
   it markedly enhanced the cell viability and promoted the colony
   formation of bone marrow mononuclear cells. Furthermore, it reversed
   the serum cytokines IL-6 and G-CSF disorders. Then, using
   transcriptomics datasets and metabonomic datasets, we integrated
   transcriptomics-based network pharmacology and metabolomics
   technologies to investigate the mechanism of action of QJSB. We found
   that QJSB regulated a series of biological processes such as
   hematopoietic cell lineage, homeostasis of number of cells, lymphocyte
   differentiation, metabolic processes (including lipid, amino acid, and
   nucleotide metabolism), B cell receptor signaling pathway, T cell
   activation and NOD-like receptor signaling pathway. In a summary, QJSB
   has protective effects to leucopenia in mice probably through
   accelerating cell proliferation and differentiation, regulating
   metabolism response pathways and modulating immunologic function at a
   system level.
   Keywords: Qi-Jing-Sheng-Bai granule, leucopenia, transcriptomics,
   metabolomics, network pharmacology
Introduction
   Chemotherapy has been widely used for the treatment of cancers.
   However, chemotherapy usually induces many adverse effects, including
   hematologic toxicity and neurotoxicity ([37]Magge and DeAngelis, 2015;
   [38]Ratti and Tomasello, 2015; [39]Zhou et al., 2018). Among them,
   hematologic toxicity, like leucopenia, is a very common adverse
   reaction that can delay the subsequent therapy, induce the risk of
   cancer metastasis, and even lead to life-threatening events ([40]Xu et
   al., 2011; [41]Cui et al., 2015). Hence the hematologic indexes,
   including the white blood cells (WBC), neutrophile granulocytes, blood
   platelets and monocytes, are important objective indexes for cancer
   patients after chemotherapy. Studies have shown that granulocyte
   colony-stimulating factor (G-CSF) and related agents have clinical
   efficacy. They are recommended to prevent leucopenia ([42]Xu et al.,
   2011). However, G-CSF only reduces the neutropenia duration for 1–2
   days while also increases adverse reactions and the cost of treatment
   notably ([43]Dygai et al., 2012; [44]Aarts et al., 2013). Traditional
   Chinese medicine (TCM) formulae have been widely used in China for the
   treatment of leucopenia ([45]Liu et al., 2014). Formulae usually
   consist of several types of Chinese medicines. Among them, one herb is
   the principal component, and the others serve as adjuvant ones to
   assist the function of the principal component. It is believed that
   multiple components contained in the formulae could hit multiple
   targets and exert synergistic effects ([46]Jiang, 2005).
   Qi-Jing-Sheng-Bai granule (QJSB) is a modern TCM formula. It is made
   from extracts of nine Chinese medicines, namely, Astragalus
   membranaceus (Huangqi), Panax quinquefolium (Xiyangshen), Epimedium
   brevicornum (Yinyanghuo), Angelica sinensis (Danggui), Polygonatum
   sibiricum (Huangjing), Eclipta pwstmta (Mohanlian), Lycium barbarum
   (Gouqi), Psoralea corylifolia (Buguzhi), and Spatholobus suberectus
   (Jixueteng), as well as one raw material component of Cervi Cornus
   Colla, at a ratio of 6:2:3:2:2:3:2:2:6:1. Both A. membranaceus and
   Cervi Cornus Colla are principal components. In a clinical study, QJSB
   has been used for the treatment of leucopenia ([47]Wu et al., 2018). In
   our previous study, we identified 143 compounds, including 56
   flavonoids, 51 saponins, and 36 other compounds, from QJSB ([48]Wu et
   al., 2018). It has been accepted that the effective ingredients can be
   detected in serum after medicine administration. After the oral
   administration of QJSB, 42 compounds, including 24 prototype compounds
   and 18 metabolites, have been detected in the serum of rats ([49]Wu et
   al., 2018). Among the 42 compounds, many ingredients have been proven
   to have bioactivities. For example, ferulic acid improves hematopoietic
   cell recovery in whole-body gamma irradiated mice and increases levels
   of granulocyte-colony stimulating factor (G-CSF) ([50]Ma et al., 2011);
   several flavonoids including formononetin, ononin, calycosin, and
   calycosin-7-O-β-D-glucoside, induce the expression of erythropoietin in
   human embryonic kidney fibroblasts via the accumulation of
   hypoxia-inducible factor-1α ([51]Zheng et al., 2011); quercitrin
   protects endothelial progenitor cells from oxidative damage via
   inducing autophagy through extracellular signal-regulated kinase
   ([52]Zhi et al., 2016); icaritin improves the hematopoietic function in
   cyclophosphamide-induced myelosuppression mice ([53]Sun et al., 2018).
   The identification of compounds absorbed into blood revealed the
   effective substance of QJSB to some extent. However, the therapeutic
   mechanism of QJSB in leucopenia remains unclear. Thus, the effect on
   the treatment of leucopenia needs further detailed investigation.
   Systems biology studies the pharmacological mechanism of TCM by
   integrating transcriptomic, proteomic and metabolomic profiles ([54]Su
   et al., 2011; [55]Meierhofer et al., 2014). Network pharmacology is a
   new system biology approach, generally describing the association of
   multiple components with multiple targets and multiple pathways
   ([56]Ning et al., 2017). Recently, the application of integrated
   systems biology and network pharmacology is a promising approach for
   the delineation of effects and mechanisms of TCM formulae.
   In this study, we firstly investigated the effect of QJSB on leucopenia
   using mice induced by cyclophosphamide. We further investigated the
   therapeutic mechanism of QJSB using the transcriptomics datasets
   derived from the bone marrow and metabonomic datasets from plasma.
   Finally, we applied transcriptomics-based network pharmacology and
   metabolomics technologies to study the mechanism of QJSB for the
   treatment of leucopenia.
Materials and Methods
Chemical Reagents
   Cyclophosphamide was purchased from Zaiqi Biotechnology Corporation
   (Shanghai, China). QJSB granules were kindly provided by Zhendong
   Pharmaceutical (Shanxi, China).
Animals and Treatments
   All animal studies were performed according to the institutional
   ethical guidelines of animal care and were approved by the Committee on
   the Ethics of Animal Experiments of the Second Military Medical
   University, China. Male ICR mice (18–22 g) were obtained from
   Laboratory Animal Company (Shanghai, China). The mice were acclimated
   for 2–3 days under conditions of controlled temperature (24 ± 2°C),
   relative humidity of 60 ± 5%, 12 h light/dark cycle, and ad libitum
   access to standard laboratory food and water. All the mice were
   randomly allocated into four groups: normal group and 3 leucopenia
   model groups (cyclophosphamide, 80 mg/kg/day). The model groups were
   treated with vehicle, leucogen (20 mg/kg/day) and QJSB (3 g/kg/day),
   respectively. The mice in each group were orally administered with
   respective medicines for 1 week, and an equivalent volume (0.2 ml/10 g)
   of 0.9% saline solution was used for normal group and model group.
   Next, the animals in each group were sacrificed by dislocation of the
   cervical vertebra and were prepared for subsequent experiments. In each
   group, the whole blood of 10 mice was used for routine blood
   examination and bone marrow cells in the femurs were used for the bone
   marrow nuclear cell count, cell viability assay and colony-forming unit
   assay. The sera of another 10 mice were used to detect the levels of
   IL-6 and G-CSF. Bone marrow cells in the femurs of three of these mice
   were collected for RNA isolation, sequencing and real-time quantitative
   PCR (RT-qPCR). The plasma of the mice was collected for metabonomic
   analysis. After 2 weeks of treatment, the mice were sacrificed by
   dislocation of the cervical vertebra and the whole blood was used for
   routine blood examination (n = 10).
Leucopenia Model
   The leucopenia model was established as follows: for 1 week of
   treatment, the mice in the model groups were treated with 80 mg/kg/day
   of cyclophosphamide intraperitoneally for 3 consecutive days (from day
   5 to day 7), and the normal group was treated with an equivalent volume
   (0.1 ml/10 g) of normal saline. For 2 weeks of treatment, the mice were
   treated with cyclophosphamide (80 mg/kg/day) intraperitoneally for 6
   days (3 consecutive days per week), and the normal group was treated
   with an equivalent volume (0.1 ml/10 g) of normal saline.
Cell Viability Assay
   Cell viability was measured using the Cell Counting Kit-8 (CCK8)
   reagent (Dojindo, Japan). The mice were sacrificed by dislocation of
   the cervical vertebra and the femurs were immediately collected. Bone
   marrow was eluted from the shaft by RPMI 1640 medium, and filtered
   through a 70 micron filter. Bone marrow nuclear cells were dispensed in
   96-well culture plates (100 μL/well) at a density of 5 × 10^5 /mL.
   Next, the cells were incubated with 10 μl of CCK8 reagent. Finally, the
   absorbance at 450 nm was measured.
Colony-Forming Units Assay
   The mice were sacrificed by dislocation of the cervical vertebra and
   the femurs were immediately harvested. Next, bone marrow cells were
   eluted from the shaft by RPMI 1640 medium, and filtered through a 70
   micron filter. Thereafter, bone marrow mononuclear cells were obtained
   by centrifugation in a Ficoll density gradient. The cells were diluted
   with M3434 methylcellulose medium (StemCell Technologies, Canada) at a
   density of 3 × 10^4/mL, dispensed into 6-well culture plates (1
   mL/well), and cultured in an atmosphere of 5% CO[2] at 37°C for 12
   days. Colonies consisting of 50 cells or more were counted.
The Detection of IL-6 and G-CSF
   Whole blood was collected from mice by removing the eyeballs. Blood
   samples were placed to clot for 2 h at room temperature before
   centrifuging for 20 min at 2000 ×g. Serum was collected and stored in
   aliquots at -80°C for later use. Commercially available sandwich
   enzyme-linked immunosorbent assay (ELISA) kits (eBiosciences, San
   Diego, CA, United States) were used for the quantitation of IL-6 and
   G-CSF. The optical density of each sample at 450 nm was measured.
   Cytokine levels were quantified using standard curves, and the values
   were expressed in units of pg/ml.
RNA Isolation, Library Preparation, and Sequencing
   The total RNA of bone marrow cells from 12 mice (leucopenia group, n =
   3, QJSB group, n = 3, normal group, n = 3, and leucogen group, n = 3)
   were extracted using TRIzol (Invitrogen, Carlsbad, CA, United States)
   reagent for RNA sequencing and were purified according to the
   manufacturer’s instructions. Strand-specific libraries were prepared
   using the VAHTS Total RNAseq Library PrepKit for Illumina (Vazyme,
   China) following the manufacturer’s instructions. Using Ribo-Zero rRNA
   removal beads, ribosomal RNA was removed from total RNA. Following
   purification, the mRNA was fragmented into small pieces using divalent
   cations under 94°C for 8 min. The cleaved RNA fragments were copied
   into first strand cDNA using reverse transcriptase and random primers.
   This is followed by second strand cDNA synthesis using DNA polymerase I
   and RNase H. These cDNA fragments then went through an end repair
   process, the addition of a single “A” base, and then ligation of the
   adapters. The products were then purified and enriched with PCR to
   create the final cDNA library. Purified libraries were quantified by
   Qubit^® 2.0 Fluorometer (Life Technologies, United States) and
   validated by Agilent 2100 bioanalyzer (Agilent Technologies, United
   States) to confirm the insert size and calculate the mole
   concentration. Cluster was generated by cBot with the library diluted
   to 10 pM, followed by sequencing on the Illumina HiSeq 2500 (Illumina,
   United States).
Data Analysis for Gene Expression
   Sequencing raw reads were preprocessed by filtering out rRNA reads,
   sequencing adapters, short-fragment reads and other low-quality reads
   using Seqtk. Hisat2 (version 2.0.4) was used to map the cleaned reads
   to the mouse GRCm38.p4 (mm10) reference genome with two mismatches.
   Gene expression was evaluated in FPKM (fragments per kilobase per
   million mapped fragments) from RNAseq data. The formula to calculate
   FPKM was as follows: FPKM = (number of mapping fragments) × 10^3 ×
   10^6/[(length of transcript) × (number of total fragments)].
   Differential expression analysis of two groups was performed using the
   “DESeq2” R package at the cutoff of | log2 fold change| > 0.585 and
   P-value < 0.05 ([57]Love et al., 2013). Then, we constructed a
   pre-ranked gene list of all differentially expressed genes ordered by
   the absolute value of log2 fold change and selected the top 300 genes
   for further analysis.
Pathway Enrichment Analysis and GO Analysis
   We firstly used R package “clusterProfiler” to perform pathway
   enrichment analysis to identify KEGG ([58]Kanehisa and Goto, 2000)
   (Kyoto Encyclopedia of Genes and Genomes) pathways enriched with the
   top 300 differentially expressed genes. Significant pathways with
   P-value < 0.05 were selected. Next, GO (Gene Ontology) enrichment
   analysis was also performed to explore the biological processes of the
   top 300 differentially expressed genes. At a cutoff of P < 0.05.
Evaluation of Drug’s Effects by the Network Scores
   The background protein-protein interaction (PPI) network was downloaded
   from the STRING database v10.5^[59]1 and the organism was chosen as
   “Mus musculus.” All genes were standardized by mapping to the Entrez ID
   for further analysis. In this paper, the top 300 DEGs under the
   treatment of a drug were regarded as the drug’s potential target genes.
   Similarly, the top 300 DEGs between the model and normal groups were
   regarded as disease associated genes. We applied the algorithm random
   walk with restart (RWR) to measure the seed genes’ influence on the
   background network. Specifically, the drug’s potential target genes and
   disease associated genes were used as seed nodes, respectively.
   Additionally, genes in the background network were scored by RWR. Next,
   we calculated the Pearson correlation coefficient between the network
   scores based on each gene set to estimate the relevance of the drug’s
   potential target genes and disease associated genes. The relevance was
   estimated as follows:
   [MATH: Relevance=cor(Scoresdrug
   ,Scoresdisease)
   :MATH]
   where cor represents the Pearson correlation coefficient and Scores
   represents the genes’ network scores. To evaluate the significance of
   the correlation between the drug’s target genes and disease genes, a
   reference distribution was built. Genes with the same number of drug’s
   target genes were randomly selected from the background network and the
   correlation coefficient was calculated between the disease genes and
   random set. We performed 100 repetitions to generate the reference
   perturbation distribution. The mean and standard deviation of the
   random correlation coefficients were denoted by μ[Relevance] and
   σ[Relevance], respectively. The Z-score was finally calculated and the
   absolute value of the Z-score larger than 3 suggests that the drug’s
   effect on the disease was statistically significant.
   [MATH:
   Zscore=|Re
   mi>levance−μRele
   mi>vance
   |σRel
   evance :MATH]
Sample Preparation and LC-MS Conditions for Metabonomic Analysis
   Because the endogenous metabolites play an essential role in the
   physiology of hosts, we explored the host metabolic profiling in the
   plasma of a subset of 27 subjects by liquid chromatography-mass
   spectrometry (LC/MS). The detailed method was as follows. Each plasma
   sample was thawed at 4°C and vortexed for 5 s at room temperature.
   Next, 100 μL of plasma was transferred into another 1.5 mL tube with
   300 μL of methanol and was mixed 45 s in a vortex. Thereafter, the
   sample was centrifuged for 10 min (12000 rpm, 4°C). Finally, the
   supernatant was transferred into auto-sampler vials and stored at -80°C
   for LC-MS analysis. The QC sample was prepared by mixing 10 μL of
   aliquot from the six above prepared samples, respectively. The QC
   samples were injected every six samples.
   Chromatographic separation was performed on a ACQUITY UPLC^® HSS T3
   (2.1 × 100 mm, 1.8 μm, Waters, United States) using an ACQUITY Ultra
   Performance LC system (Waters corp., Milford, MA, United States). The
   column was maintained at 40°C. The flow rate was set at 0.4 mL/min, and
   the sample injection was 1 μL. The optimal mobile phase consisted of a
   linear gradient system of water mixed with 0.1% formic acid (phase A)
   and acetonitrile (phase B): 0–6.0 min, 5–100% B, 6.0–8.0 min, 100% B;
   8.0–9.0 min, 100–90% B; 9.0–14.0 min, 90–80% B; 14.0–14.1 min, 80–5% B;
   14.1–19.0 min, 5% B. MS detection was acquired on a Micromass
   Quadrupole (Q) SYNAPT G2-Si high-resolution mass spectrometer (Waters
   Corp., Milford, MA, United States) equipped with an electrospray ion
   (ESI) source. Both positive and negative modes were utilized in the
   current research. The temperature of the ion source was 120°C. The
   capillary voltage and cone voltage were 2000 V and 49V, respectively.
   The desolvation gas temperature and flow were 350°C and 750 L/h,
   respectively. The cone gas was set at 50 L/h. Data were collected
   between 50 and 1200 m/z with a 0.2 s scan time and a 0.02 s interscan
   delay. All analyses were conducted using the lock spray to ensure the
   accuracy and precision of the mass information for compound
   identification. Leucine encephalin [(M + H)^+ = 556.2771, (M-H)^- =
   554.2615] was used as the lock spray at a concentration of 1 μg/mL, and
   the flow rate was set at 5 μL/min. Additionally, mass spectrometry
   elevated energy (MS^E) collection was applied for compound
   identification. This technique obtains precursor ion information
   through low collision energy and full-scan accurate mass fragment
   information through the ramp of the high collision energy. The
   collision energy of MS^E was set from 15 to 35 V.
Metabonomic Data Processing and Analysis
   The raw plasma LC-MS data were pre-processed using Waters Progenesis QI
   2.0 software (Non-linear Dynamics, Newcastle, United Kingdom).
   Progenesis QI includes the steps of importing data, reviewing
   alignment, experiment design setup, picking peaks, identifying and
   reviewing compounds, and performing compound statistical analysis.
   Then, the data were exported into SICMA 14.1 (Umetric, Umeå, Sweden)
   for multivariable statistical analysis. The multivariate statistical
   analysis (MVA) included principal component analysis (PCA), partial
   least squares discrimination analysis (PLS-DA), and orthogonal partial
   least square-discriminant (OPLS-DA) models, which were used to observe
   the classifications for different groups. Thereafter, based on the
   OPLS-DA plot, the ions were filtered by VIP > 1 (variable importance in
   the projection) to identify the metabolites contributing to the
   classifications. Next, ions with P-values < 0.05 were regarded as the
   differential metabolite ions. Subsequently, the differential
   metabolites ions with the two filters were structurally identified and
   interpreted based on the metabonomic associated databases:
   METLIN^[60]2, HMDB^[61]3, and KEGG^[62]4. Finally, using the
   MetaboAnalyst 4.0, we performed pathway analysis for the metabolites
   contributing to the classifications and identified the most relevant
   pathways.
RNA Extraction and Real-Time Quantitative PCR
   Total RNA was extracted in bone marrow cells from three groups
   (leucopenia, QJSB and normal groups) mice using the Trizol reagent
   (Thermo Fisher Scientific) according to the manufacturer’s
   instructions. And cDNA was generated using the High-Capacity cDNA
   Reverse Transcription Kit (Thermo Fisher Scientific). RT-qPCR was
   performed using the Stratagene Mx3005P RT-PCR System (Applied
   Biosystems) and the PowerUp^TM SYBR^® Green Master Mix (Thermo Fisher
   Scientific), according to the protocol. Melt curves were analyzed at
   the end of each assay to confirm the specificity. Fold change was
   determined using the 2^-ΔΔCT method normalized with endogenous control
   GAPDH. The PCR primers used are listed in [63]Supplementary Table S1.
Statistical Analysis
   GraphPad was used for statistical analysis of the biochemical data. The
   animals were randomly assigned by using the random permutations table.
   The data were expressed as the means ± standard deviation (SD). The
   data were analyzed using by two-tailed Student’s t-test or one-way
   analysis of variance (ANOVA). P < 0.05 was considered statistically
   significant. The transcriptomics data were processed by R package with
   “DESeq2” and “clusterProfiler.” SICMA 14.1 (Umetric, Umeå, Sweden) was
   used for MVA. Cytoscape was used to trace the associated gene–enzyme
   relationship using KEGG database.
Results
QJSB Increased Peripheral WBCs and Platelets in Leucopenia Model Mice
   After treatment with cyclophosphamide, the peripheral WBCs and
   platelets were significantly decreased. After 1 week of treatment, QJSB
   increased peripheral WBCs (P < 0.001) and platelets (P < 0.001)
   significantly (approximately 2.6-fold and 2.4-fold, respectively)
   compared with those in model group ([64]Figure 1A,B). Administration of
   QJSB or cyclophosphamide had no significant effect on the other
   peripheral hemogram parameters such as RBCs and hemoglobin
   concentration ([65]Figure 1C,D). We also got the similar results when
   the leucopenia model animals were treated by QJSB for 2 weeks
   ([66]Figure 1E,F). For WBC differential counts at 1 week of treatment,
   cyclophosphamide decreased the percentage of monocytes and increased
   the percentage of eosinophils. The percentage of eosinophils returned
   to normal after being administrated with QJSB and leucogen. In
   addition, an increase was observed in the percentage of basophils in
   QJSB and leucogen groups ([67]Figure 2).
FIGURE 1.
   [68]FIGURE 1
   [69]Open in a new tab
   The effect of QJSB on the peripheral WBC (A), platelet (B), RBC (C),
   and HGB (D) parameters in leucopenia mice induced by cyclophosphamide.
   After 1 week of treatment, QJSB increased peripheral WBCs (A) and
   platelets (B) compared with model group, but had no significant effect
   on the other peripheral hemogram parameters such as RBCs (C) and
   hemoglobin concentration (D). After 2 week of treatment, QJSB also
   increased peripheral WBCs (E) and platelets (F). Data are presented as
   means ± SD. ^###Represent P < 0.001 vs. normal group and ^∗, ^∗∗, and
   ^∗∗∗ represent P < 0.05, 0.01, and 0.001 vs. model group, respectively.
FIGURE 2.
   [70]FIGURE 2
   [71]Open in a new tab
   The effect of QJSB on WBC differential counts: neutrophil (A),
   lymphocyte (B), monocyte (C), eosinophil (D), and basophil (E) in
   leucopenia mice induced by cyclophosphamide. Cyclophosphamide increased
   the percentage of eosinophils (D), and QJSB returned it to normal. An
   increase was observed in the percentage of basophils (E) in QJSB group.
   Data are presented as means ± SD. ^#Represent P < 0.05 vs. normal group
   and ^∗, ^∗∗, and ^∗∗∗ represent P < 0.05, 0.01, and 0.001 vs. model
   group, respectively.
QJSB Increased Bone Marrow Nuclear Cells and Enhanced Cell Viability in
Leucopenia Model Mice
   The cell number and cell viability of bone marrow nuclear cells were
   significantly decreased in the cyclophosphamide treatment group (P <
   0.05). QJSB significantly increased the number of bone marrow nuclear
   cells, and enhanced the cell viability (P < 0.001) ([72]Figure
   3A–[73]C).
FIGURE 3.
   [74]FIGURE 3
   [75]Open in a new tab
   The effect of QJSB on the cell number and cell viability of bone marrow
   nuclear cells, colony formation of bone marrow mononuclear cells and
   cytokines secretion. QJSB significantly increased the number of bone
   marrow nuclear cells (A,B), enhanced the cell viability (C) and
   promoted colony formation of bone marrow mononuclear cells (D). QJSB
   significantly reversed the increases of G-CSF (E) and IL-6 (F) induced
   by cyclophosphamide. Data are presented as means ± SD. ^###Represent P
   < 0.001 vs. normal group and ^∗ and ^∗∗∗ represent P < 0.05 and 0.001
   vs. model group, respectively.
QJSB Promoted Bone Marrow Mononuclear Cells Colony Formation
   To determine the effect of QJSB on bone marrow hemopoietic
   stem/progenitor cells, we performed the methylcellulose semisolid
   colony-forming units assay. Mononuclear cells were extracted from the
   bone marrow of ICR mice. Colony formation of bone marrow mononuclear
   cells was significantly decreased by cyclophosphamide. After 1 week of
   treatment, the colony number and colony size were both significantly
   increased by QJSB (P < 0.001) ([76]Figure 3D).
QJSB Reversed Cytokines Secretion in Serum of Leucopenia Model Mice
   The hematopoiesis-related cytokines are important factors for the
   regulation of hematopoietic function ([77]Alexander, 1998). Both G-CSF
   and IL-6 in serum were detected. Compared with the normal control
   group, after cyclophosphamide treatment, the levels of G-CSF and IL-6
   in serum were dramatically increased from 100.6 and 5.5 pg/ml to 1143.0
   and 89.0 pg/ml, respectively. QJSB significantly reversed the increases
   of G-CSF (from 1143 to 345 pg/ml, P < 0.001) ([78]Figure 3E) and IL-6
   (from 89.0 to 9.4 pg/ml, P < 0.001) ([79]Figure 3F) induced by
   cyclophosphamide.
Differential Expression Genes Identification and Functional Analysis
   In order to identify potential molecular mechanisms, high-throughput
   sequencing was used to identify the affected gene by QJSB in bone
   tissue. The raw data of fastq format of RNAseq are available through
   the National Center for Biotechnology Information’s Gene Expression
   Omnibus (GEO^[80]5), and the GEO series accession number is
   [81]GSE120707
   . Then, the top 300 differentially expressed genes between QJSB
   treatment and model group were identified, which included 172
   upregulated and 128 downregulated genes. Comparing the leucopenia
   groups with the normal groups, the top 300 differentially expressed
   genes, with 14 upregulated and 286 downregulated genes, were detected.
   Additionally, comparing the leucogen groups with the leucopenia groups,
   the top 300 differentially expressed genes, with 177 upregulated and
   123 downregulated genes, were also identified. The details of the top
   300 differentially expressed genes are listed in [82]Supplementary
   Table S2. To identify potential affected pathways of QJSB, KEGG pathway
   enrichment analysis was performed using the top 300 differentially
   expressed genes between QJSB and model group. We found that
   “hematopoietic cell lineage,” “osteoclast differentiation, “B cell
   receptor signaling pathway, “NOD-like receptor signaling pathway,”
   “arachidonic acid metabolism,” and “Ferroptosis” were significantly
   enriched (P < 0.05) ([83]Figure 4, left). To further identify the
   biological processes, we did GO terms enrichment analysis and found the
   most significantly enriched terms are “homeostasis of number of cells,”
   “cellular response to TGF-β stimulus,” “TGF-β receptor signaling
   pathway,” “response to TGF-β,” “lymphocyte differentiation,”
   “regulation of immune effector process,” and “T cell activation”
   ([84]Figure 4, right). The detail parameters of pathways and GO terms
   are shown in [85]Tables 1, [86]2. These results indicate that QJSB may
   influence these pathways and biological process, thus increasing
   peripheral WBCs and platelets in leucopenia model mice.
FIGURE 4.
   [87]FIGURE 4
   [88]Open in a new tab
   Pathway enrichment analysis and GO analysis. KEGG pathway enrichment
   analysis for top 300 differentially expressed genes in QJSB-treated
   mice is shown left. GO analysis for top 300 differentially expressed
   genes in QJSB-treated mice is shown right.
Table 1.
   Pathways enrichment analysis of differently expressed genes in bone
   marrow cells of QJSB-treated mice.
   ID       Description                         GeneRatio P-value
   mmu04380 Osteoclast differentiation           0.0550   0.0035
   mmu04662 B cell receptor signaling pathway    0.0390   0.0049
   mmu04621 NOD-like receptor signaling pathway  0.0550   0.0148
   mmu04640 Hematopoietic cell lineage           0.0390   0.0154
   mmu04216 Ferroptosis                          0.0240   0.0248
   mmu00590 Arachidonic acid metabolism          0.0310   0.0480
   mmu04974 Protein digestion and absorption     0.0310   0.0497
   [89]Open in a new tab
Table 2.
   GO enrichment analysis of differently expressed genes in bone marrow
   cells of QJSB-treated mice.
   ID         Description                           GeneRatio P-value
   GO:0002697 Regulation of immune effector process  0.0540   0.0000
   GO:0030098 Lymphocyte differentiation             0.0540   0.0001
   GO:0042110 T cell activation                      0.0610   0.0001
   GO:0019369 Arachidonic acid metabolic process     0.0220   0.0001
   GO:0048872 Homeostasis of number of cells         0.0430   0.0003
   GO:0071560 Cellular response to TGF-β stimulus    0.0320   0.0003
   GO:0071559 Response to TGF-β                      0.0320   0.0004
   GO:0007179 TGF-β receptor signaling pathway       0.0280   0.0004
   [90]Open in a new tab
RWR-Based Evaluation of QJSB
   As mentioned above, the top 300 differentially expressed genes were
   identified from leucopenia-normal groups, leucogen-leucopenia groups,
   QJSB-leucopenia groups, respectively. We took the top 300 genes of each
   set as seeds to apply the RWR algorithm. In total, 153 genes from
   leucopenia-normal groups were mapped to the background network and set
   as disease associated genes, while 252 genes from QJSB and 233 genes
   from leucogen were mapped and set as drug’s potential target genes. We
   calculated the Z-score as described in Materials and Methods. The
   results are listed in [91]Table 3. As shown in [92]Table 3, the Z-score
   for QJSB is 6.156 (larger than 3), and it is 10.823 for leucogen. These
   results suggest that QJSB and leucogen have significant effects against
   leucopenia in mice from perspective of network analysis.
Table 3.
   The effect scores of QJSB and leucogen on leukopenia.
   Drug       QJSB  Leucogen
   Overlap    252     233
   Revelance 0.1248  0.1590
   Z-score   6.1560 10.8230
   [93]Open in a new tab
Differential Metabolites Identificationand Metabolic Pathway Analysis
   The plasma samples were subjected to LC/MS analysis in both the
   positive ion mode (ESI+) and negative ion mode (ESI-). To discriminate
   the metabolic profiles among normal, model control and QJSB group, we
   performed clustering analysis using PCA, and the supervised PLS-DA and
   OPLS-DA. The plasma sample from different groups tended to separated
   according to the PCA plots either in ESI+ or ESI-mode ([94]Figure 5A).
   Furthermore, the PLS-DA score scatter plots further evidenced the
   significant separation among the normal, model and QJSB groups either
   in ESI+ or ESI-mode ([95]Figure 5B). To further identify the
   significant metabolites contributing to the classifications among these
   three groups, supervised OPLS-DA was adopted between two groups either
   in the ESI+ or ESI- modes together. The permutations plot was used to
   assess the OPLS-DA model and the results showed the model was highly
   significant and non-overfitting ([96]Supplementary Figure S1). The
   quality of the OPLS-DA model was shown in [97]Supplementary Table S3.
   The result suggested that there was the remarkable separation in model
   vs. normal and model vs. QJSB. There were 51 and 47 metabolites
   differently regulated in leucopenia (vs. normal) and QJSB treatment
   (vs. leucopenia model) mice, respectively ([98]Supplementary Table S4).
   Then, in order to identify the key metabolic pathway, we did metabolic
   pathway enrichment analysis using MetaboAnalyst 4.0 ([99]Tables 4,
   [100]5). As shown in [101]Figure 6A, in leucopenia model (vs. normal),
   the differential metabolites primarily participate in
   glycerophospholipid metabolism, primary bile acid biosynthesis
   phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine
   metabolism. These metabolic anomalies were found to be primarily
   involved in lipid metabolism and amino acid metabolism. After QJSB
   treatment (vs. leucopenia model), the differential metabolites also
   were primarily enriched in lipid metabolism (glycerophospholipid
   metabolism, ether lipid metabolism, and linoleic acid metabolism) and
   amino acid metabolism (tryptophan metabolism) ([102]Figure 6B). The
   results indicate that QJSB is likely involved in the modulation of the
   metabolic disorders.
FIGURE 5.
   [103]FIGURE 5
   [104]Open in a new tab
   Analysis of metabolic profiles from normal, model and QJSB groups based
   on UPLC-QTOF-MS. The SIMCA-derived PCA (A) and PLS-DA (B) score plot
   among three groups either in ESI+ or ESI– mode, respectively.
Table 4.
   Pathways enrichment analysis of differential metabolites in bone marrow
   cells of model mice.
   Term Total Expected Hits Raw P-value
   Phenylalanine, tyrosine, and tryptophan biosynthesis 4 0.0565 1 0.0553
   Glycerophospholipid metabolism 30 0.4234 2 0.0650
   D-Glutamine and D-glutamate metabolism 5 0.0706 1 0.0687
   Taurine and hypotaurine metabolism 8 0.1129 1 0.1077
   Limonene and pinene degradation 8 0.1129 1 0.1077
   Phenylalanine metabolism 11 0.1553 1 0.1452
   Glycosylphosphatidylinositol (GPI)-anchor biosynthesis 14 0.1976 1
   0.1812
   Citrate cycle (TCA cycle) 20 0.2823 1 0.2489
   Butanoate metabolism 22 0.3105 1 0.2702
   Alanine, aspartate, and glutamate metabolism 24 0.3387 1 0.2910
   Primary bile acid biosynthesis 46 0.6493 1 0.4855
   Purine metabolism 68 0.9598 1 0.6286
   Aminoacyl-tRNA biosynthesis 69 0.9739 1 0.6341
   Steroid hormone biosynthesis 72 1.0162 1 0.6501
   [105]Open in a new tab
Table 5.
   Pathways enrichment analysis of differential metabolites in bone marrow
   cells of QJSB-treated mice.
   Term Total Expected Hits Raw P-value
   Glycerophospholipid metabolism 30 0.3387 3 0.0040
   Synthesis and degradation of ketone bodies 5 0.0565 1 0.0553
   Linoleic acid metabolism 6 0.0677 1 0.0660
   Alpha-Linolenic acid metabolism 9 0.1016 1 0.0974
   Ether lipid metabolism 13 0.1468 1 0.1378
   Glycosylphosphatidylinositol (GPI)-anchor biosynthesis 14 0.1581 1
   0.1476
   Butanoate metabolism 22 0.2484 1 0.2225
   Steroid biosynthesis 35 0.3952 1 0.3312
   Arachidonic acid metabolism 36 0.4065 1 0.3390
   Tryptophan metabolism 40 0.4517 1 0.3691
   Purine metabolism 68 0.7678 1 0.5467
   [106]Open in a new tab
FIGURE 6.
   [107]FIGURE 6
   [108]Open in a new tab
   Metabolic pathway analysis of the differential metabolites using the
   MetaboAnalyst 4.0. (A) Representative pathway analysis of the
   metabolites in leucopenia mice. (B) Representative pathway analysis of
   the metabolites in QJSB-treated mice. All the matched pathways are
   displayed as circles. The color and size of each circle was based on
   the P-value and pathway impact value, respectively. The smaller P-value
   means the pathway with higher levels of significance.
Correlation Networks Construction of Differential Genes and Metabolites
   In order to obtain a comprehensive view of the complex mechanisms of
   QJSB, we combined the transcriptomics-based network pharmacology and
   metabolomics data to obtain a system-wide view of the therapeutic
   mechanism of QJSB. Using the Metscape plugin of Cytoscape, we
   constructed the correlation network between the differential genes and
   differential metabolites regulated in QJSB-treated mice to analyze
   their potential relationships. The results suggested that a lot of
   metabolites and genes were in the same metabolic pathways, including
   glycerophospholipid metabolism, linoleate metabolism, squalene and
   cholesterol biosynthesis, glycine, serine, alanine and threonine
   metabolism, histidine metabolism, tryptophan metabolism, purine and
   pyrimidine metabolism, etc. As shown in [109]Figure 7, these metabolic
   pathways mainly were mainly grouped into three classes: lipid
   metabolism, amino acid metabolism and nucleotide metabolism.
FIGURE 7.
   FIGURE 7
   [110]Open in a new tab
   Correlation networks construction, including lipid metabolism (A),
   amino acid metabolism (B), and nucleotide metabolism (C), between the
   differential metabolites and differentially expressed genes. The dark
   red hexagonal represents detected metabolites, the shallow red
   hexagonal represents in-direct metabolites. The green square represents
   protein (enzyme). The blue circle represents genes that code for
   corresponding proteins.
   In the lipid metabolic pathways, the levels of metabolites such as
   phosphatidylcholine (lecithin) and 2-lysolecithin were elevated, and
   the expression of some genes encoding important metabolic enzymes like
   Pcyt1a, Phospho1, Cyp4f18, Alox5, and Ggt5 were also augmented by QJSB
   treatment. Amino acids and nucleotides are essential components of
   proteins and nucleic acids, respectively, and amino acid metabolism and
   nucleotide metabolism play an important role in biological synthesis
   and metabolism of amino acids and nucleotides ([111]Gutteridge and
   Coombs, 1977; [112]Ballantyne, 2001; [113]Bender, 2012). In these
   metabolic pathways, the level of the metabolite tryptamine and the
   expression of GGTLA1, HDC, NDST1, and ATP6V1C2 were increased, while
   the level of the metabolite deoxyadenosine and the expression of
   ATP6V1G2, ATP2B2, and POLR3H were decreased. These results suggested
   that QJSB might affect biological synthesis and metabolism of amino
   acids and nucleotides by regulating amino acid metabolism and
   nucleotide metabolic pathways.
QJSB Increased the Gene Expression of Ggt5, Cyp4f18, Pcyt1a, Alox5, and
Phospho1 in Leucopenia Model Mice
   To further investigate the effects of QJSB on the regulation of
   metabolic pathways, we measured the expression of five genes, Ggt5,
   Cyp4f18, Pcyt1a, Alox5, and Phospho1, according to our previous data.
   They are key genes encoding important metabolic enzymes. RT-qPCR was
   performed in bone marrow cells from leucopenia model mice induced by
   cyclophosphamide. Compared to the normal control, the expressions of
   Ggt5, Cyp4f18, Pcyt1a, Alox5, and Phospho1 were significantly decreased
   in leucopenia model groups. QJSB significantly increased the mRNA
   levels of these genes ([114]Figure 8, P < 0.01). These results are
   consistent with our data from transcriptomics analysis.
FIGURE 8.
   [115]FIGURE 8
   [116]Open in a new tab
   The effects of QJSB on the expression of five lipid metabolism related
   genes (Ggt5, Cyp4f18, Phospho1, Alox5, and Pcyt1a) in bone marrow cells
   from leucopenia model mice. Data are presented as means ± SD. ##
   represents P < 0.01 vs. normal group and ^∗∗ represents P < 0.01 vs.
   model group.
Discussion
   Leucopenia is a very common adverse reaction induced by chemotherapy
   ([117]Xu et al., 2011; [118]Cui et al., 2015). In China, TCM formulae
   have been widely used to treat leucopenia. Among them, QJSB is a newly
   developed TCM formula and has been used clinically. In this study, our
   experiments conclude that QJSB has protective effects against
   leucopenia. As the theory of pharmachemistry of TCM, more scientists
   accept the viewpoint that the effective constituents may be detected in
   serum ([119]Wang, 2006). We have identified 24 prototype compounds in
   the serum of rats after the oral administration of QJSB ([120]Wu et
   al., 2018), which revealed the potential active substances of the
   formula to some extent ([121]Supplementary Table S5). The network
   pharmacology technology is a powerful tool to investigate the
   therapeutic effects and molecular mechanisms ([122]Zhao et al., 2009;
   [123]Zhang et al., 2017). We also employed a transcriptomics-based
   network pharmacology approach to determine that the mechanism was
   involved in the cell proliferation and differentiation, metabolism
   response and immunologic function. Functional enrichment analysis was
   performed to explore the biological processes of the top 300
   differentially expressed genes. Usually, the top 300 differentially
   expressed genes under the treatment of a drug are regarded as the
   drug’s potential target genes, and the top 300 differentially expressed
   genes between the model and control groups are regarded as disease
   associated genes. The relevant parameters between the drug’s potential
   target genes and disease associated genes and the Z-score were
   calculated to evaluate the effect of drugs. A Z-score value greater
   than 3 often indicates a statistically significant deviation between
   the actual value and the random ones ([124]Fang et al., 2017). In this
   study, the Z-score was 6.156. Thus, QJSB might have significant effects
   against leucopenia disease. Using the transcriptomics-based network
   pharmacology and metabonomics technology, we propose a model for QJSB
   multi-pathways treatment mechanism ([125]Figure 9). We concluded that
   QJSB mainly participates in the metabolism response, cell proliferation
   and differentiation, and the immune response, etc.
FIGURE 9.
   FIGURE 9
   [126]Open in a new tab
   Multi-pathways treatment mechanism of QJSB on leucopenia in mice. The
   orange rectangle represents the key gene and the black rectangle
   represents the key metabolite. Red arrow represents up-regulated.
   The hematopoietic cell lineage is mainly involved in blood cells
   development progresses from a rare population of hematopoietic stem
   cells (HSCs). HSCs can undergo either self-renewal or differentiation
   into multilineage committed progenitor cells: common lymphoid
   progenitors (CLPs) or common myeloid progenitors (CMPs), and
   successively become more restricted in their differentiation capacity.
   They finally generate functionally mature cells such as lymphocytes,
   granulocytes, monocytes, and erythrocytes, et al. Among them,
   lymphocytes, including B and T cells, constitute a major proportion
   (more than 80%) of leukocytes ([127]Dintzis and Treuting, 2011;
   [128]O’Connell et al., 2015). B and T cells are the primary effector
   cells during the adaptive immune response ([129]Medzhitov and Janeway,
   1997; [130]Iwasaki and Medzhitov, 2015). B cell receptor signaling
   pathway is involved in B lymphocyte proliferation, differentiation,
   survival and activation ([131]Jacob et al., 2002; [132]Schweighoffer et
   al., 2013; [133]Reth and Nielsen, 2014). T cell activation is a vital
   event for immune system, and only the activated T cell can exert an
   efficient immune response. Cd3d and Tnfsf13b are key genes in these
   pathways. The protein encoded by Cd3d is part of the T-cell
   receptor/CD3 complex and is involved in T-cell activation and signal
   transduction. Cd3d-deficient patients show a complete block in T cell
   development. Deficiency of Cd3d also impairs T cell-dependent functions
   of B cells and causes severe immunodeficiency ([134]de Saint Basile et
   al., 2004; [135]Gil et al., 2011; [136]Munoz-Ruiz et al., 2016). The
   protein encoded by Tnfsf13b plays roles in the survival and maturation
   of both of B and T cells ([137]Pfister et al., 2011; [138]Liu et al.,
   2016). Besides lymphocytes, both eosinophils and basophils are also
   involved in the immune response ([139]Jacobsen et al., 2011;
   [140]Voehringer, 2011). The imbalance of eosinophils and basophils
   might also affect the hematopoiesis ([141]Tebbi et al., 1980;
   [142]Enokihara et al., 1996; [143]Schneider et al., 2010). In this
   study, the expression levels of Cd3d and Tnfsf13b were both
   up-regulated in QJSB group and recovered the abnormity of eosinophils
   and basophils induced by cyclophosphamide. These data indicate that
   QJSB might participate in the regulation of the immune effector
   process.
   Although most HSCs normally exist in a quiescent or dormant state
   ([144]Wilson et al., 2008), some of them divide and support the
   production of all mature blood cell types through multiple intermediate
   progenitor stages, during the steady state, and in response to
   urgencies to maintain blood cell number homeostasis ([145]Busch et al.,
   2015; [146]Sawai et al., 2016; [147]Grinenko et al., 2018). Itgam is
   mainly involved in adhesion and migration of leukocytes. It is
   necessary for HSCs expansion in vitro and engraftment in vivo
   ([148]Prashad et al., 2015). Patients with Itgam variants have reduced
   switched memory B-cell counts ([149]Maggadottir et al., 2015). Ets1 is
   a key transcription factor required for CD8 T cell differentiation
   ([150]Zamisch et al., 2009). It is a critical regulator of group 2
   innate lymphoid cells expansion and cytokines production ([151]Zook et
   al., 2016). In this study, the different expression genes of Itgam and
   Ets1 are simultaneously enriched in QJSB group (vs. leucopenia group).
   These data indicate that HSCs expansion, lymphocyte differentiation and
   cytokines production may also be involved in the protective mechanism
   of QJSB.
   Hematopoiesis-related cytokines are important factors for the
   regulation of hematopoietic function ([152]Alexander, 1998). For
   example, IL-6 was first identified and characterized as a
   lymphocyte-stimulating factor according to its ability to promote the
   activation and population expansion of T cells, the differentiation and
   survival of B cells, and the regulation of the acute-phase response
   ([153]Hunter and Jones, 2015). G-CSF, also known as colony-stimulating
   factor 3 (Csf3), is the major hematopoietic growth factor involved in
   the control of neutrophil development. G-CSF supports the
   proliferation, survival, and differentiation of neutrophilic progenitor
   cells in vitro and provides non-redundant signals for the maintenance
   of steady-state neutrophil levels in vivo ([154]van de Geijn et al.,
   2003). G-CSF also participates in the development of other myeloid
   lineages, the mobilization of HSCs and myeloid cell migration
   ([155]Liongue et al., 2009). To determine how G-CSF was regulated by
   QJSB, we constructed a subnetwork by extracting the links between G-CSF
   and differentially expressed genes under the treatment of QJSB from our
   background PPI network, i.e., the STRING network ([156]Supplementary
   Figure S2). This network shows that G-CSF interacts with a group of
   differentially expressed genes, including Itgam, Il7r, Il18, Ccr2,
   Dpp4, Jun, and Ltf. Among these genes, Itgam and G-CSF receptor (CSF3R)
   are two markers of granulocyte differentiation and it was found that
   G-CSF could decrease Itgam expression ([157]Lantow et al., 2013;
   [158]Lin et al., 2015). IL-18 (interleukin-18) is involved in the
   hematopoietic progenitor cell growth and stimulates the secretion of
   IL-6 and the expression of G-CSF mRNA in splenic adherent cells
   ([159]Ogura et al., 2001). Additionally, IL-18 treatment increases the
   serum G-CSF level in C57BL/6 mice ([160]Kinoshita et al., 2011). It was
   reported that when immortalized bone marrow progenitors are induced by
   G-CSF to differentiate into mature neutrophils, the CCR2 gene is
   strongly activated and CCR2 play a critical role in monocyte
   recruitment ([161]Iida et al., 2005). G-CSF also increases CCR2 protein
   expression of THP-1 monocytes ([162]Chen et al., 2008). As our data
   shows, Itgam was up-regulated while Il18 and Ccr2 were down-regulated
   by QJSB, a finding that was consistent with the decrease in the serum
   G-CSF level. Excessive activation and release of cytokines impair the
   hematopoietic function, and exhaust the production of hematopoietic
   factor ([163]Hara et al., 2004). QJSB reversed the excessive exhaustion
   of certain cytokines induced by cyclophosphamide, which might be
   beneficial for the recovery of leucopenia.
   Qi-Jing-Sheng-Bai granule also modulates the metabolism response,
   including lipid metabolism, amino acid metabolism and nucleotide
   metabolism. In lipid metabolism, the levels of metabolites such as
   phosphatidylcholine (lecithin) and 2-lysolecithin are elevated, and the
   expression of some genes encoding important metabolic enzymes like
   Pcyt1a, Phospho1, Cyp4f18, Alox5, and Ggt5 are also augmented by QJSB
   treatment. Additionally, RT-qPCR was performed to verify that QJSB
   upregulated their mRNA levels. Phosphatidylcholine participates in a
   series of biological activities such as biological membranes synthesis,
   cell proliferation and platelet activation ([164]Ridgway, 2013; [165]Li
   et al., 2014; [166]O’Donnell et al., 2014). Metabolic enzymes encoded
   by Pcyt1a regulate the biological synthesis of phosphatidylcholine
   ([167]Haider et al., 2018). The high expression of Pcyt1a causes
   elevated levels of phosphatidylcholine, which may result in accelerated
   biological membranes synthesis and cell proliferation of WBCs and
   platelets. Additionally, Cyp4f18, Alox5, and Ggt5 are involved in the
   processes of generation, transformation and degradation of leukotriene
   ([168]Christmas et al., 2006; [169]Rådmark et al., 2015). Thus, QJSB
   may promote lipid production by regulating lipid metabolism, and
   regulate immune and inflammatory responses by affecting the generation,
   transformation and degradation of leukotriene.
   Amino acids and nucleotides are essential components of proteins and
   nucleic acids, respectively. They are indispensable for cell
   proliferation, survival and development. Leucogen and vitamin B4 are
   very commonly used for the treatment of leucopenia. Leucogen is an
   analog of cysteine while vitamin B4 is a precursor of adenine
   ([170]Lecoq, 1957; [171]Whelan, 2005; [172]Zheng et al., 2006;
   [173]Langhammer et al., 2011). Therefore, regulating amino acid
   metabolism and nucleotide metabolism have been confirmed to cure
   leucopenia. Our data indicate that QJSB participate in the biological
   synthesis and metabolism of energy, nutrition and genetic materials,
   which are essential for cell proliferation, development and maturation.
Conclusion
   In summary, our data reveal the therapeutic mechanism of QJSB by
   integrative application of transcriptomics-based network pharmacology
   and metabolomics technologies. QJSB exerts protective effect against
   leucopenia in mice through participating in multi-pathways, mainly
   including accelerating cell proliferation and differentiation,
   regulating metabolism response pathways and modulating immunologic
   function.
Ethics Statement
   All animal studies were performed according to the institutional
   ethical guidelines of animal care and were approved by the Committee on
   the Ethics of Animal Experiments of the Second Military Medical
   University, China.
Author Contributions
   ST, PH, and YG collected and analyzed the data, and drafted and revised
   the manuscript. JY, RW, and JZ collected and revised the manuscript. WZ
   and A-JL designed the study, collected the data, and revised the
   manuscript. All authors read and approved the final manuscript.
Conflict of Interest Statement
   The authors declare that the research was conducted in the absence of
   any commercial or financial relationships that could be construed as a
   potential conflict of interest. The handling Editor declared a shared
   affiliation, though no other collaboration, with several of the authors
   at the time of review.
   Funding. The work was supported by Professor of Chang Jiang Scholars
   Program, NSFC (81520108030 and 21472238), Shanghai Engineering Research
   Center for the Preparation of Bioactive Natural Products (16DZ2280200),
   the Scientific Foundation of Shanghai China (13401900103 and
   13401900101), and the National Key Research and Development Program of
   China (2017YFC1700200).
   ^1
   [174]https://string-db.org/
   ^2
   [175]https://metlin.scripps.edu/
   ^3
   [176]www.hmdb.ca
   ^4
   [177]https://www.genome.jp/kegg/
   ^5
   [178]http://www.ncbi.nlm.nih.gov/geo/
Supplementary Material
   The Supplementary Material for this article can be found online at:
   [179]https://www.frontiersin.org/articles/10.3389/fphar.2019.00408/full
   #supplementary-material
   FIGURE S1
   Distinct discrimination by comparison between Normal vs. Model (A,C),
   Model vs. QJSB (B,D) either in ESI+ and ESI-. OPLS-DA was used to
   distinguish the cluster and its permutations plot was used to assess
   the current OPLS-DA model.
   [180]Click here for additional data file.^ (1.2MB, zip)
   FIGURE S2
   The protein-protein network of Csf3 (G-CSF) with differentially
   expressed genes between QJSB and model group. Csf3 (G-CSF) was
   surrounded by differentially expressed genes based on the STRING
   database.
   [181]Click here for additional data file.^ (1.2MB, zip)
   TABLE S1
   The primers of the key genes encoding important metabolic enzymes.
   [182]Click here for additional data file.^ (1.2MB, zip)
   TABLE S2
   The top 300 differentially expressed genes were identified in Model vs.
   Normal, QJSB vs. Model and Leucogen vs. Model groups.
   [183]Click here for additional data file.^ (1.2MB, zip)
   TABLE S3
   Summary of the LC-MS data sets used in OPLS-DA modeling. R2X (cum)
   represents the cumulative X-variation modeled after components, R2Y
   means the fraction of Y-variation modeled in the component, and Q2
   expresses overall cross-validated R2Y for the component and is used to
   an estimate the model prediction. Cumulative values of R2X, R2Y, and Q2
   close to 1 indicate an excellent model.
   [184]Click here for additional data file.^ (1.2MB, zip)
   TABLE S4
   Differential metabolites of plasma in Model vs. Normal and QJSB vs.
   Model were identified by OPLS-DA on SIMCA software. RT is retention
   time on gas chromatograph. MZ is the ratio of protons and charge
   number. Fold change is the ratio of relative abundance of differential
   metabolites. The data were calculated by t test.
   [185]Click here for additional data file.^ (1.2MB, zip)
   TABLE S5
   The active substances of absorbed prototype compounds in QJSB and
   theirs evidence.
   [186]Click here for additional data file.^ (1.2MB, zip)
References