Based on the research method of network pharmacology, this study finally predicted 27 active ingredients, 122 potential targets, 762 Go analysis and 154 KEGG pathways of Astragalus-Scorpion drug pair in the treatment of PCa. The interaction of multi-ingredient, multi-target and multi-pathway further demonstrated the principle of traditional Chinese medicine treatment of PCa from the pharmacological and molecular levels: consolidate the root, eliminate the source of disease, strengthening the body, eliminate pathogen.
Modern pharmacological studies have confirmed that the chemical ingredients of Astragalus-Scorpion drug pair are mainly flavonoids, saponins and polysaccharides , which can improve immunity, promote metabolism, regulate blood glucose, improve the function of the heart, inhibit virus, and have anti-tumor effect .The chemical ingredients of Scorpion are mainly Scorpion venom, steroid derivatives, alkaloids and other small molecular ingredients. The enzymatic hydrolysate of Scorpion venom can inhibit the growth of tumor cells and induce tumor cell apoptosis to achieve anti-tumor effect . In this study, most of the ingredients screened by the Astragalus-Scorpion drug pair were flavonoids, such as quercetin, kaempferol, formononetin, calycosin and so on. Relevant studies have found that quercetin can promote AGS cell apoptosis by increasing the production of reactive oxygen species (ROS), reduce the expression of anti-apoptotic protein and increase the expression of pro-apoptotic protein . In addition, quercetin can reduce the expression of genes associated with the apoptotic pathway, such as VEGFB. Abdur Rauf et al.  also showed that quercetin has inhibitory effect on a variety of cancers, high toxic effect on tumor cells, and less toxic and side effects on normal tissue cells, indicating that quercetin has a high targeting effect on killing tumor cells. Kaempferol has been used for cancer chemotherapy, which has many pharmacological properties, such as anti-bacteria, anti-inflammation, anti-oxidation, anti-tumor, cardiac-protection, neuro-protection and anti-diabete. Its mechanisms of anti-cancer include induction of apoptosis, G2/M-phase cell cycle arrest, down-regulation of markers related to epithelial mesenchymal transformation (EMT), and phosphoinositi-3kinase/protein kinase B signaling pathways . Relevant studies have shown that formononetin can play an anti-tumor effect by regulating signal pathways such as JAK-STAM , and the expression of caspase, 1VI1VIPS, GSK-3P, Axin and other molecules in vivo and in vitro [23-26]. It is reported that Formononetin can inhibit the proliferation of PCa cells mainly through MAPK, PI3K /Akt and IGF-1 / IGF-1R pathways. Calycosin can improve immune function, enhance the effect of anti-oxidation, anti-radiation and anti-cancer, and has the function of lowering blood fat, blood sugar and reducing complications of diabetes. Its anti-tumor effect is mainly to increase the expression level of MMP9 and P-Akt by expressing C-Metu87，and further to prevent the invasion of cancer cells . In conclusion, the main active ingredients of Astragalus-Scorpion drug pair in the treatment of Pca were collected comprehensively in this study.
The common targets (JUN, AKT1, IL6, MAPK1 and RELA)are at the core of PPI interaction network, which may play an important role in the treatment of prostate cancer with Astragalus-Scorpion drug pair. JUN is the first found carcinogenic transcription factor. c-JUN is an AR co-activator, which stimulates AR trans-activation by mediating receptor dimerization and subsequent DNA binding, and plays a key role in the proliferative function of fibroblasts and the anti-proliferative activity of finasteride on epithelial cells . IL6, a glycogen composed of 184 amino acids, is a pluripotent cytokine that affects tumor cell activity and plays an important role in immune response and inflammation [29,30]. Studies have shown that IL6 can interfere inflammatory environment, induce tumor occurrence, carry out microenvironment immune regulation and induce apoptosis of cancer cells [31-33]. These effects are performed through a variety of pathways, among which signal transducers and activators of transcription play the most important roles . In addition, studies have shown that IL6 is overexpressed in a variety of cancer cells, and it is significantly increased in advanced cancer [33,35]. MAPK signaling pathway plays a key role in various cancers through hyperactivation and is an important part of cancer pathway. MAPK can transfer extracellular signals into various cellular processes, such as cell proliferation, cell survival, cell death and cell differentiation [36,37]. The current evidence clearly shows that MAPK pathway is a feasible target for cancer treatment . AKT1 is an important gene involved in tumor invasion and angiogenesis. AKT1 is the core target of PI3K/Akt signaling pathway, which plays a role in regulating cell proliferation, cell apoptosis, cell cycle, cell metabolism, protein transcription and angiogenesis. Abnormal activation of Akt can avoid apoptosis and promote cell survival, which is related to the occurrence of tumor [39,40]. According to current research, exogenous AKT1 promotes the migration and invasion of breast cancer cell. The growth and invasion of breast cancer cells can be inhibited by specifically inhibiting the expression of AKT1 . RELA, a kind of NF-KB, can induce the expression of various proteins involved in inflammation and carcinogenesis, such as FAS, cyclin, IL-2, tumor necrosis factor(TNF), CXCL1 and matrix metallopeptidase (MMPs), which can promote the survival and proliferation of tumor cells, inflammatory response, anti-apoptosis, angiogenesis and metastasis [42-44]. Studies have shown that the abnormal activation of NF-KB / RELA and the imbalance of microRNA are related to the cell proliferation of non-small cell lung cancer. MicroRNA affects cell proliferation of non-small cell lung cancer by degrading RELA or inhibiting its expression. For example, mir506 selectively eliminates lung cancer cells by inhibiting the expression of RELA, producing reactive oxygen species and activating p53 .
In this study, by inputting common targets for GO analysis and KEGG analysis, it was found that targets of Astragalus-Scorpion drug pair for PCa mainly concentrated in cancer-related pathways, PI3K-Akt signaling pathway, AGE-RAGE signaling pathway, TNF signaling pathway and so on. GO analysis mainly involves transcription from RNA polymerase II promoter, apoptotic process, DNA transcription and other biological processes. The active ingredients of Astragalus-Scorpion promote the apoptosis of PCa cells by inhibiting the cell proliferation and cell differentiation, and is related to the biological regulation and biological process of tumor cells. PI3K-Akt signaling pathway is one of the most classic tumor survival pathways, which plays an important role in the proliferation and differentiation of tumor cells [46,47]. Fizazi et al.  found that inhibition of PI3K-Akt signaling pathway can effectively prevent the proliferation and differentiation of prostate cancer cells. Yan et al.  believed that activation of PI3K-Akt signaling pathway would inhibit the transcription of FOXO, a subgroup of downstream apoptotic related gene forkhead box transcription factor, and increase the level of FOXO phosphorylation, so as to block the apoptosis of PCa cells. AGE is the product of the Maillard reaction between sugars and proteins in human body. RAGE, a membrane protein belonging to the immunoglobulin superfamily, is named because it acts as the receptor of AGE and interacts with it to produce biological effects [50,51]. AGE-RAGE signaling pathway plays an important role in the occurrence and development of prostate cancer . Elangovan et al.  found that specific blocking RAGE and its downstream targets can induce apoptosis and inhibit proliferation of prostate cancer cells in vivo and in vitro. In addition, relevant studies have shown that the activation of AGE-RAGE signaling pathway can further activate PI3K-Akt signaling pathway to promote the proliferation of prostate cancer cells .
According to the results of molecular docking, the binding energies between the core active ingredient and the core target are all less than 0 kcal/mol, indicating that there is a possibility of binding between the active ingredient and the target. The binding energy less than or equal to -5.0 kcal/mol is considered to have good binding ability . The binding energies of quercetin with AKT1, quercetin with RELA and kaempferol with AKT1 were all less than -5.0 kcal/mol, and the number of hydrogen bonds was more than or equal to 4, indicating that their binding ability was strong and stable. Quercetin and kaempferol, the active ingredients, selectively inhibit the activation of PI3K-Akt signaling pathway by binding to AKT1, a key target in the PI3K-Akt signaling pathway, so as to inhibit the proliferation of prostate cancer cells. This may be one of the important molecular mechanisms of Astragalus-Scorpion drug pair in the treatment of PCa in this study.
Based on the methods of network pharmacology and molecular docking technology, this study explained the effect and mechanism of Astragalus-Scorpion drug pair in the treatment of PCa through multiple ingredients, multiple targets, biological functions, and signaling pathways, providing beneficial reference and scientific basis for the in-depth research, product development and clinical application of this drug pair.