Because of the existence of various alkaloids in EREPL was confirmed through GC-MS. Plant secondary metabolites are well-classified and acknowledged as bioactive substances for both primary and secondary prevention in the treatment of cancer [12–14]. These substances influence metabolic and signaling pathways, limiting angiogenesis and inhibiting the development of microtubules in cells. The most important groups of secondary metabolites are called flavonoids, terpens, saponins, lignans, steroids, alkaloids, and phenolics. Glucosides are also included in this group. Because these plant-based bioactive substances have the much-needed geno-protective actions, such as protecting healthy cells from DNA damage, they can be used to create customized cancer prevention programs for either individuals or groups. Alkaloids are a promising group of phytochemicals that have anticancer properties [15]. Alkaloids are small organic compounds that often consist of nitrogen in a ring. They are secondary metabolites of plants. Alkaloids make up 20% of plant species. They play a key role in defending plants against diseases and herbivores [16].
For predicting the physicochemical and pharmacokinetic characteristics of piperlonguminine in the current study, Swiss ADME, pkCSM, and ProToxII were employed. For any drug, analysis of ADMET is essential [17, 18]. With regard to the pharmacokinetics and physicochemical characteristics of piperlonguminine found in EREPL, the current study's usage of ADMET revealed a good intestine absorption rate of 94.721%. Additionally, no carcinogenicity, hepatotoxicity, cytotoxicity or mutagenicity were detected by the Protox-II examination. In addition, piperlonguminine complies with the Lipinski's rule, according to ADME characteristics. The rule states that all drugs must meet the five essential physiochemical requirements. The parameters are: HBD should be less than five, HBA should be less than ten, MW should not be above 500 Daltons, lipophilicity (MLOGP) should not be above 5, and TPSA should be under 140 Å [19, 20]. Piperlonguminine met each of the five physiochemical criteria in the current study. The molecular weight is 273.33 g/mol, the number of HBA and HBD were three and one, respectively, the value of MLOGP and TPSA were 2.14 and 47.56 Å respectively.
Any naturally occurring compound must satisfy the druglikeness requirements in order to be classified as a successful drug [17]. Piperlonguminine is a member of benzodioxoles [21]. The benzodioxole ring system is extensively distributed in nature and can be found in a wide range of natural compounds, including safrole, piperonal, and several alkaloids [22].Regarding piperlonguminine's ability to fight cancer, there is no information available. Using network pharmacology-based research, we hypothesised the effect of piperlonguminine in the EREPL on SRC, MTOR, EZH2, and MAPK3 that participate in the colorectal cancer pathway, ErbB, and mTOR pathway, which play an instrumental part in colorectal cancer. Two alkaloids were found in the ethanolic extract according to the GCMS results. We examined the toxicity, ADMET, and ADME characteristics of both alkaloids. Only piperlonguminine, which had neither toxicity nor any breaches of the Lipinski rule was chosen for further investigation. The canonical smile of piperlonguminine was entered in two online databases, the SwissTargetPrediction and TCMSP, in order to determine the possible targets. There were 100 protein targets from SwissTargetPrediction and 11 targets from TCMSP. DisGeNET, GeneCards, and the Open Targets Platform databases were used to screen the targets of colorectal cancer. DisGeNET, GeneCards, and Open Targets Platform yielded 2832, 24607, and 7383 target genes, respectively. The colorectal cancer target genes from DisGeNET, GeneCards, and Open Targets Platform were overlapped using Venny 2.1.0 to determine the intersection between them. There were 1865 common target genes in all. The 1865 target genes of colorectal cancer and the 111 target genes of piperlonguminine were then overlapped similarly. As a result, 51 common genes, SOAT1, NTRK1, PRF1, ESR2, MAPK3, IDO1, SRC, NR3C1, KDR, CDK2, HDAC6, TGFBR1, PIK3CD, AURKA, NAMPT, TERT, CDK1, TTK, HDAC1, RET, ABL1, MTOR, PARP1, PFKFB3, JAK2, IKBKB, KCNH2, CCKBR, PRKDC, PIK3CB, HCK, BRAF, EPHB4, EZH2, CDK4, CTSB, MAPK8, JAK3, HDAC3, ADORA2B, CFTR, DDR2, PDGFRA, CHEK2, CTSD, CSNK2A1, PTGER3, LIMK1, CHEK1, RXRA and SAA1, were obtained by employing Venny 2.1.0. The relationship between the 51 possible target genes were examined using a PPI network built using the STRING database. Selecting Homo sapiens as the organism all 51 targets were submitted to the multiple protein list of STRING. Using CytoNCA application from Cytoscape 3.2.1, the PPI network was provided to Cytoscape 3.2.1 in order to weed out the best four hub genes, SRC, MTOR, EZH2 and MAPK3. Hub genes are characterized by their extensive interconnection with other genes [17]. Topological considerations were used to screen-out hub genes. Supposedly, in light of the outcomes of molecular docking, piperlonguminine showed strong binding affinity with SRC, MTOR, EZH2, and MAPK3, representing that it has good remedial effects in the treatment of colorectal cancer.
Based on the findings of GLOBOCAN 2018, colorectal cancer (also known as CRC) is the third most deadly and the fourth most widespread kind of cancer in the humankind [23]. CRC risk is increased by a variety of factors. People over 50 are more likely to develop CRC, whereas those under 50 have a chance of 4% [24]. People in developing nations who have begun to follow Western diets tend to consume less fiber and more animal proteins and fat [25], therefore, becoming more prone to CRC. In addition to this people with history of CRC polyps [26], are equally prone. The risk of colon cancer can be increased by genetic disorders that have been passed down through the generations within the family. Type II diabetes [27], and a lack of exercise [28] can all raise the risk of colon cancer. Nevertheless the significant amount of work that has been put in over the past few years to develop diagnostics and therapies options, the prevalence of CRC remains extremely high in both women and men [29]. Depending on the stage of the cancer, radiation and/or neoadjuvant chemotherapy may be administered before or after surgery, even though surgery is the primary therapeutic option for patients with possibly curable CRC [4]. Despite these efforts, recurrent disease can develop in up to 30% of patients in stage I–III and more than 65% of patients in stage IV [30]. Due to acquired drug resistance, these traditional treatments are typically linked to high rates of tumor regrowth and recurrence [31]. Natural substances derived from plants, such as flavonoids [32], terpenoids [33], saponins [34], coumarins [35] andxanthones [36], were described to impede CRC. The compound piperlonguminine was screened in the current investigation because it did not violate Lipinski's rule and did not cause any toxicity. Subsequent research on piperlonguminine's network-based pharmacology has sought to determine how it affects CRC. The hub genes, SRC, MTOR, EZH2, and MAPK3 can communicate themselves at variable degrees in both healthy and colon cancer cells. More than 80% of human colon tumors have elevated SRC expression and activity. It is a non-receptor protein tyrosine kinase [37]. The upregulation of SRC in colon cancer cells increases the adhesion, invasion, and migration of cells [38]. SRC is required for the mTOR-dependent signaling pathway to function [39]. The often activated mTOR signalling pathway regulates synthesis of protein and transcription to regulate differentiation of immune cell and proliferation of cells. It significantly affects metabolism of tumour as well [40]. Downregulation of SRC is therefore important. In CRC, MTOR affects translational processes, cell adhesion, and metabolism. High tumor mutation burden (TMB) and a number of tumor-infiltrating immune cells (TIICs) are associated with high MTOR expression. MTOR acts as the chief regulator of mTOR signaling pathway [41]. This pathway is one of the most improperly regulated signalling pathways because it regulates transcription and synthesis of protein to control proliferation of cells and differentiation of immune cells, and also has a substantial impact on metabolism of tumour [40]. Therefore, downregulation of MTOR gene is crucial. MAPK3, also called as ERK1, is a crucial cell signaling protein in the ERK/MAPK pathway. MAPK3 causes phosphorylation of the downstream cytoplasmic protein of ERK/MAPK pathway, activating a number of nuclear transcription factors, like, c-fos and c-Jun, which in turn promotes cell expansion and death. The initiation, growth, migration of cancer cells, and resistance to drugs in a variety of carcinomas, including liver, thyroid, lung, and stomach malignancies, have all been linked to the overexpression and/or hyperactivity of MAPK3. Consequently, its downregulation is crucial [42]. EZH2 aids in the growth, invasion, apoptosis, angiogenesis, and metastasis of cancer cells. Numerous neoplasias affecting the ovaries, prostate, bladder and breast have been discovered to overexpressed it in their tumor tissues [43]. Increased expression of EZH2 is linked to CRC development. Early in the development of colorectal tumors, EZH2 expression occurs. Its overexpression has a role in early epigenetic changes that happen as adenoma development progresses from normal epithelial cells [44]. Therefore, making its downregulation necessary.
The ShinyGo 0.76 and DAVID databases were used to show the relationship between GO and KEGG. The target hub genes SRC, MTOR, EZH2 and MAPK3 are involved in a variety of cellular structure, cellular activity, and molecular roles in human development, according to the GO analysis. Using the DAVID web tool, the function of genes was displayed in the KEGG pathway maps. With the aid of the KEGG database, it is simpler to comprehend the fundamental properties and workings of living organisms, including organisms, cells and the environment. KEGG is a computational model of the biological system composed of genes, molecules, proteins, and chemical substances [45]. Results from the target-pathway network showed that 56 KEGG pathways were involved. The colorectal cancer pathway is the most important of the 56 KEGG pathways because, within it, nine other pathways, including cell cycle, apoptosis, Wnt, PI3K-Akt, MAPK, TGF-β, and mTOR signalling pathways, participate and serve an instrumental part in colorectal cancer (Fig. 6) [45]. The colorectal cancer pathway involves the two hub genes MTOR and MAPK3. ErbB and mTOR signalling pathways are two of the nine pathways that have been identified in the DAVID database. With SRC, MTOR, and MAPK3 in the ErbB signalling pathway and MTOR and MAPK3 in the mTOR signalling pathway, which can affect colorectal cancer, the colorectal cancer pathway is noteworthy due to the involvement of two or more of these hub genes in each of the two pathways. The EZH2 hub gene, on the other hand, is not found in any of the pathways that the DAVID database returned. The current study provides fresh insight into the effect of piperlonguminine on EZH2 in addition to its effects on SRC, MTOR, and MAPK3.
The top four hub genes, MTOR, SRC, MAPK3, as well as EZH2, were individually docked with piperlonguminine using Autodock 4 for disease-target network analysis. When docked with piperlonguminine, SRC protein displayed the highest binding energy (-7.22 kcal/mol), followed by MAPK3 (− 6.42 kcal/mol), EZH2 (− 6.3 kcal/mol), and MTOR (− 6.14 kcal/mol) (Table 6). The 3D and 2D pictures of the protein-ligand complex (Table 6) produced from docking were then visualized using Discovery Studio. The resultant amino acids of SRC, GLU A:162, TYR B:152, LYS A:198, interact with the piperlonguminine through H-bond with a bond length of 2.89Å, 2.06 Å and 1.85 Å, respectively. Similar to this, H-bond interactions occur between the following amino acids of MAPK3: [ILE B:190 (3.39 Å)], EZH2: [ASN A: 119 (2.1 Å)], and MTOR: [GLN A: 2194 (3.24 Å ), ASP A: 2191 (2.78 Å ), TYR A: 2225 (2.96 Å ), and ASP A: 2357 (2.47 Å )] (Fig. 7).