Xihuang pills induce apoptosis in hepatocellular carcinoma by suppressing phosphoinositide 3-kinase/protein kinase- B/mechanistic target of rapamycin pathway

BACKGROUND The phosphoinositide 3-kinase/protein kinase-B/mechanistic target of rapamycin(PI3K/Akt/mTOR) signalling pathway is crucial for cell survival, differentiation, apoptosis and metabolism. Xihuang pills(XHP) are a traditional Chinese preparation with antitumour properties. They inhibit the growth of breast cancer, glioma, and other tumours by regulating the PI3K/Akt/mTOR signalling pathway. However, the effects and mechanisms of action of XHP in hepatocellular carcinoma(HCC) remain unclear. Regulation of the PI3K/Akt/mTOR signalling pathway effectively inhibits the progression of HCC. However, no study has focused on the XHPassociated PI3K/Akt/mTOR signalling pathway. Therefore, we hypothesized that XHP might play a role in inhibiting HCC through the PI3K/Akt/mTOR signalling pathway.AIM To confirm the effect of XHP on HCC and the possible mechanisms involved.METHODS The chemical constituents and active components of XHP were analysed using ultra-performance liquid chromatography-quadrupole time of flight mass spectrometry(UPLC-Q-TOF-MS). Cellbased experiments and in vivo xenograft tumour experiments were utilized to evaluate the effect of XHP on HCC tumorigenesis. First, SMMC-7721 cells were incubated with different concentrations of XHP(0, 0.3125, 0.625, 1.25, and 2.5 mg/mL) for 12 h, 24 h and 48 h. Cell viability was assessed using the CCK-8 assay, followed by an assessment of cell migration using a wound healing assay.Second, the effect of XHP on the apoptosis of SMMC-7721 cells was evaluated. SMMC-7721 cells were stained with fluorescein isothiocyanate and annexin V/propidium iodide. The number of apoptotic cells and cell cycle distribution were measured using flow cytometry. The cleaved protein and mRNA expression levels of caspase-3 and caspase-9 were detected using Western blotting and quantitative reverse-transcription polymerase chain reaction(RT-qPCR), respectively.Third, Western blotting and RT–qPCR were performed to confirm the effects of XHP on the protein and mRNA expression of components of the PI3K/Akt/mTOR signalling pathway.Finally, the effects of XHP on the tumorigenesis of subcutaneous hepatocellular tumours in nude mice were assessed.RESULTS The following 12 compounds were identified in XHP using high-resolution mass spectrometry:Valine, 4-gingerol, myrrhone, ricinoleic acid, glycocholic acid, curzerenone, 11-keto-β-boswellic acid, oleic acid, germacrone, 3-acetyl-9,11-dehydro-β-boswellic acid, 5β-androstane-3,17-dione, and 3-acetyl-11-keto-β-boswellic acid. The cell viability assay results showed that treatment with 0.625mg/mL XHP extract decreased HCC cell viability after 12 h, and the effects were dose-and timedependent. The results of the cell scratch assay showed that the migration of HCC cells was significantly inhibited in a time-dependent manner by the administration of XHP extract(0.625mg/mL). Moreover, XHP significantly inhibited cell migration and resulted in cell cycle arrest and apoptosis. Furthermore, XHP downregulated the PI3K/Akt/mTOR signalling pathway, which activated apoptosis executioner proteins(e.g., caspase-9 and caspase-3). The inhibitory effects of XHP on HCC cell growth were determined in vivo by analysing the tumour xenograft volumes and weights.CONCLUSION XHP inhibited HCC cell growth and migration by stimulating apoptosis via the downregulation of the PI3K/Akt/mTOR signalling pathway, followed by the activation of caspase-9 and caspase-3.Our findings clarified that the antitumour effects of XHP on HCC cells are mediated by the PI3K/Akt/mTOR signalling pathway, revealing that XHP may be a potential complementary therapy for HCC.

Network pharmacology analysis combined with experimental verification of the molecular mechanism of Xihuang pill in treating liver cancer

Background:Xihuang pill is a kind of traditional Chinese medicine,which has been widely used in the treatment of kinds of cancer.However,there is still a lack of systematic understanding of the molecular mechanism of Xihuang pill in the treatment of liver cancer.In this work,we aim to explore the molecular mechanism of Xihuang pill in treating liver cancer.Methods:The functional components in Xihuang pill were collected from Traditional Chinese Medicine Database and Analysis Platform.The target genes of these components were also collected using Traditional Chinese Medicine Database and Analysis Platform.The target genes of liver cancer were predicted using GeneCards database.The intersecting genes were then analyzed with Venn diagrams.Kyoto Encyclopedia of Genes and Genomes and Database for Annotation,Visualization,and Integrated Discovery were used to analyze the pathway.Then,cell counting kit-8 was used to measure the half-maximal inhibitory concentration of Xihuang pills.The living dead cell staining method was used to observe the survival of cells.HepG2 cell apoptosis was tested by flow cytometry with fluorescein isothiocyanate/propidium iodide double staining method,and then the mitochondrial damage was also detected by flow cytometry.The expression of target genes was detected by quantitative real-time polymerase chain reaction.Results:A total of 130 compounds and 198 genes were identified as potential active ingredients and putative liver cancer‑related targets.We obtained 1,899 disease targets and 297 transcriptome targets from the database.Six drug-disease intersecting genes,CCNB1,BIRC5,TOP2A,ESR1,IGF2 and IGFBP3 were obtained.They are enrichment in apoptosis,PI3K-AKT signaling pathway,MAPK signaling pathway,pathways in cancer and p53 signaling pathway.Besides,it was found that the apoptosis rate of the HepG2 cells in Xihuang pill treated group was significantly higher than that of the control group.And the apoptosis rate gradually increased in a dose dependent manner of Xihuang pill treatment.Xihuang pill also induced the mitochondrial membrane potential damage.Compared with the control group,the expression level of CCNB1 and BIRC5 was induced,while the expression level of IGF2 was reduced after Xihuang pill treatment.Conclusion:Xihuang pill may act on six proteins(CCNB1,BIRC5,TOP2A,ESR1,IGF2 and IGFBP3)and cover multiple pathways to form a therapeutic network to treat liver cancer.