Mechanisms predictive of Tibetan Medicine Sophora moorcroftiana alkaloids for treatment of lung cancer based on the network pharmacology and molecular docking

Lung cancer (LC), as an exceedingly significant public health problem in developing and developed countries, has a high incidence and mortality rate, and it is one of the most common malignant tumors in clinical practice [1]. In recent years, the incidence and mortality rate of LC patients have been showing an upward trend. Currently, although the surgery treatment for LC can be effective, the overall prognosis is poor [2]. With its advantages of low toxicity, and multi-component and multi-target mechanism [3], traditional Chinese medicine can not only provide new and effective candidate drugs for the treatment of cancer diseases, but also has a good application prospect and research value [4]. The combination of traditional Chinese and Western medicine can effectively treat LC and significantly improve the efficiency of treatment [5]. Therefore, screening the effective components of traditional Chinese medicine as effective drugs for treating LC is of great significance.

Leguminous Sophora moorcroftiana (SM) is a genuine medicinal material in Tibet. Its alkaloids have various biological activities, including bacteriostasis, antitumor, and anti-parasite [6]. A continuous in-depth study on the biological activity of SMA found that the inhibitory effect of alkaloid extracts on the proliferation of lung adenocarcinoma cells SPC-A-1 and GLC-82 showed significant dose and time effects. Still, the mechanism of action was unclear [7].

As a new analytical technology, network pharmacology analysis can integrate biological multicomponent and multitarget activities, because it is consistent with the integrity and systematicness of traditional Chinese medicine [8‐10]. This discipline is suitable for the in-depth mining of potential active ingredients in traditional Chinese medicine, especially for screening and exploring the mechanism of the effective components of a single drug [11, 12]. Molecular docking technology can predict the binding mode and binding energy of the receptor and ligand by knowing the structural characteristics of the receptor and ligand and the interaction force between them, and further screen out the optimal binding mode of drug molecular ligands and docking receptors. This technology can not only reveal the molecular mechanism of receptor-ligand binding, but also contribute to the pharmacology of traditional Chinese medicine compounds and single drugs. Therefore, this study aim was to apply network pharmacology, molecular docking and cell Experimental Verification to reveal the underlying mechanism by which SMA effects for LC, and to predict the main active compounds and core targets of SMA for the treatment of LC, as well as provide a scientific basis for the biological activity interpretation of LC.

In this study, we use network pharmacological approach to reveal the potential moleculai mechanisms of SMA in LC. Through Cytoscape software and PPI network 33 core targets were screened out from the SMA component and LC disease regulatory network. Among the intersection targets of SMA components and LC, oxysophocarpine (degree: 20) has the highest number, followed by oxymatrine (degree: 19). Previous research shows that oxymatrine, matrine, oxysophocarpine, sophocarpine, sophoridine and cytisine have different inhibitory effects on LC cell lines [15‐19]. Such as oxymatrine can induce apoptosis of the human LC non-small cell LC cell line A549 [20, 21], and oxysophocarpine has an excellent inhibitory effect on liver cancer, colorectal cancer and other cell lines [22, 23].

By constructing the SMA and LC disease intersection targets gene interaction regulatory network, the targets with degree > 10 were selected as ALB, CCND1, ESR1, Notch1, AR, CDK2, HSP90AA1 and E2F1. CCND1 and CDK2 were both expressed in non-small cell lung cancer, and CCND1 was highly expressed in non-small cell lung cancer tissues (42%). The expression of CDK2 in non-small cell lines and tissue samples was negatively correlated with the expression of microRNA-597 [24]. The rs3213172C/T polymorphism of the E2F1 gene can be used as an effective biomarker for the genetic susceptibility of LC in the Chinese population [25].Therefore, the selected core targets can not only be used as markers of LC but may also become one of the key targets for the treatment of LC.

Based on the GO prediction of the BP pathway, MF pathway, CC pathway and KEGG signaling pathways by DAVID, the biological pathway is involved in the positive regulation of DNA template transcription; the molecular pathway is involved in transcription factor binding, enzyme binding and the same protein binding; and the cellular pathway is involved in protein complexes and exosomes. These results indicated that SMA might affect protein recombination by affecting protein complexes. The protein and exosomes were used to regulate the binding process of enzymes, thus affecting the transcriptional regulation of DNA templates.

Among the 21 pathways, the most significantly enriched pathways include Pathways in cancer, Thyroid hormone signaling pathway, PI3K/Akt signaling pathway, P53 signaling pathway, FoxO signaling pathway and AMPK signaling pathway. The PI3K/Akt pathway is involved in important processes, such as cell proliferation, cell cycle progression, metastasis, survival and apoptosis. It is also one of the most important oncogenic targets in almost all types of cancer. The PI3K/Akt signaling pathway plays a crucial role in the occurrence and metastasis of lung cancer, not only showing high expression in non-small cell lung cancer [26], but also playing a key role in the cell survival and being abnormally activated in the development of cancer. Such as ILTPs inhibit the growth and proliferation of lung cancer A549 cells by regulating the PI3K/Akt signaling pathway, suppressing the PI3K/Akt pathway activated by oxidative stress, and inhibiting the expression of PI3K and Akt [27, 28]. Camellia Leave Saponins can significantly inhibit the proliferation of NCI-H1975, A549 and HCC827 cells, inducing cell autophagy and suppressing tumor growth through the PI3K and MAPK signaling pathways [29]. Isoliquiritigenin, a compound found in licorice, induces growth inhibition and cell apoptosis in A549 lung cancer cells by inhibiting the activation of the PI3K/AKT/mTOR signaling pathway [30]. Docosahexaenoic acid, a 22-carbon omega-3 fatty acid, induces cell death in human non-small cell lung cancer cells by inhibiting mTOR through the PI3K/AKT pathway [31]. White peony extract induces cell apoptosis and autophagic cell death in human lung cancer cells by inhibiting the PI3K/Akt/mTOR pathway [32]. The nuclear translocation of nuclear factor κB (NF-κB) promotes the expression of p65 protein and the transcription of CCND1. The overexpression of CCND1 further promotes the development of lung cancer A549, leading to cell proliferation and inducing cell cycle arrest at the S phase. After CCND1 expression, the activity of the PI3K/Akt signaling pathway significantly increases [33]. Polygalacin D reduces the expression level of CDK2 protein, further slowing down the progression and metastatic risk of lung cancer A549 [34]. P53, as the most commonly mutated gene in cancer cells, is frequently involved in regulating the expression of genes related to cell proliferation and nuclear growth. P53 negatively regulates the expression of transcriptional activator 3 (STAT3), thereby exerting a significant inhibitory effect on cell proliferation, migration and invasion [35]. Increasing evidence suggests that mutated p53 plays an important role in the occurrence, invasion and migration of lung cancer [36, 37]. Such as Calvatia gigantea extract can reduce the expression of CCND1 and increase the expression of p53 in lung cancer A549 cells, further inducing cell cycle arrest and apoptosis [38, 39]. Sesamin can inhibit the expression of CDK2 and induce cell cycle arrest at the G1 phase and apoptosis in lung cancer A549 cells by regulating the Akt/p53 pathway. This further reduces the growth and metastasis of lung cancer [40]. AMPK is a downstream effector of SIRT1 and a key regulator of autophagy. Through the SIRT1/AMPK signaling pathway, it activates the formation of autophagosomes and increases the number of autophagolysosomes in lung cancer A549 cells, thereby promoting cell apoptosis [41]. FOXO proteins are involved in various cellular processes, including cell differentiation, cell apoptosis, cell proliferation, DNA damage, repair and functioning as mediators of oxidative stress [42]. Activation of the PI3K/AKT pathway leads to the phosphorylation and inactivation of FOXO transcription factors. This results in the downregulation of FOXO target genes involved in cell cycle arrest, apoptosis and cellular metabolism [43]. Such as miR-411 in lung cancer downregulates FOXO1, further influencing cell proliferation and cell survival in lung cancer [44]. The overexpression of lncFOXO1 suppresses the viability, colony formation and invasion of A549 cells, while increasing CCND1 expression, further activating the PI3K/AKT signaling pathway to exert anti-proliferative effects [45]. The findings from the aforementioned study are consistent with the results of our research, suggesting that the target proteins CDK2, CCND1, and E2F1 may serve as potential biomarkers and crucial therapeutic targets in lung cancer. The PI3K-Akt signaling pathway, p53 signaling pathway, FoxO signaling pathway and AMPK signaling pathway collectively regulate and influence the proliferation and survival of lung cancer cells.

To further validate the therapeutic effect of SMA on LC, molecular docking was performed to verify the interaction between the six alkaloid monomers of SMA and the target proteins 2W96, 2CCH, and 1O96. The results of molecular docking demonstrated that the six active components exhibited favorable binding affinity with the selected target proteins, forming the best complexes. In addition, the rationality of the results of network pharmacological screening was to further confirmed by cell experiments in vitro. This finding provides supporting evidence for the rationality of the network pharmacological screening results, suggesting the potential therapeutic efficacy of SMA in LC. The study provided a preliminary elucidation of the mechanism of SMA in treating lung cancer.

Although our study has identified potential biomarkers and key target proteins and signaling pathways for the treatment of lung cancer, there are still some limitations. Therefore, further cell-based experiments are necessary to elucidate the mechanisms of these targets and signaling pathways. For instance, we will further evaluate the impact of SMA on the proliferation of lung cancer cell lines H1299, H1975, PC9 and A549, and assess their therapeutic potential. Additionally, we will employ techniques such as Western blotting and molecular biology to validate key proteins and signaling pathways, and further explore the interactions between these pathways. Our subsequent experimental research will address these gaps and provide more evidence for the treatment of SMA on the LC.

In this study, network pharmacology combined with molecular docking was used to elucidate the mechanism by which SMA regulate LC through multiple targets and channels. The results showed that oxymatrine, matrine, oxysophocarpine, sophocarpine, sophoridine and cytisine of SMA could form the best complex with 2W96, 2CCH and 1O96 target proteins, and to further verify the therapeutic effect of SMA in LC A549 cell, which also can provide a reliable reference basis that SMA were potential candidates in treating LC.