Plant material
The bulbs of F. cirrhosa were collected from several sites of Kashmir Himalya. The permissions and licenses were obtained from the concerned authorities for collection of the plant material. The plant material collected was identified and authenticated from Centre for Biodiversity and Taxonomy (CBT), Department of Botany, University of Kashmir, vide no. F(voche/specimen) CBT/KASH/21; specimen voucher number 2952-(KASH); Dated:20/7/20.
Permission and Guidelines: It is stated that all the permissions and licenses were obtained from the concerned authorities for collection of the plant material. Further it is stated that all methods were performed in accordance with the relevant guidelines and regulations during collection, identification, preparation of herbarium and extraction.
Data availability
Te datasets supposing the current study are available in public database from STITCH (http://stitch.embl.de/), Swiss Target Prediction (http://www.swisstargetprediction.ch/), GeneCards (https://www.genecards.org/), MalaCards (https://www.malacards.org/), STRING (http://www.string-db.org/), DrugBank (https://go.drugbank.com/), and PDB (https://www.pdb.org).
Extraction
The air-dried bulbs of the experimental plant was grounded into a fine powder using mixer grinder. Different polarity gradient organic solvents including petroleum ether, ethyl acetate, and methanol were used, to extract the plant material by Soxhlet method. The dried extracts were stored in airtight glass vials at 4℃ for future use.
High resolution-liquid chromatography-mass spectrometry (HR-LC/MS)
The phytochemical profile of crude extracts obtained from F. cirrhosa bulb parts were analyzed using a HR-LC/MS technique. Compounds were identified based on their mass spectra and unique mass fragmentation patterns. Several public databases such as Compound Discoverer 2.1, ChemSpider, and PubChem were used as the primary resources used to identify the phytochemical constituents in F.cirrhosa 32.
Screening for active constituents
The phytocompounds from F. cirrhosa in the scientific literature and their structures in "canonical smile" and "sdf" file format were retrieved using publicly available small molecule databases such as Dr. Dukes DB) (https://phytochem.nal.usda.gov/ phytochem/search) and Phyto-chemical interactions database (PCIDB; https://www.genome.jp/db/pcidb). Using Swiss Target Prediction (http://www.swisstargetprediction.ch/), STITCH: chemical association networks (http://stitch.embl.de/), PubChem (https://pubchem.ncbi.nih.gov/), and Therapeutic Target Database (TTD) (http://bidd.nus.edu.sg/group/cjttd/), the predicted targets of the aforementioned phytocompounds were determined. To acquire complete data, we combined the targets from the aforementioned databases and designated them as phytocompound targets.
Prediction of the potential target gene for the quantitative component and disease
The target genes retrieved from the two databases were merged. Standardization of the gene name and defnition of the species as "human" was performed using the UniProtKB function in the UniProt (https://www.uniprot.org/) database. GeneCards (https://www.genecards.org/ ) and MalaCards (https://www.malacards.org/), the human gene database, were used to retrieve breast cancer-related genes. Te keywords used in the search were limited to "breast cancer" and "mammary carcinoma". The targets obtained were compared to those retrieved earlier and target genes linked to breast cancer were selected.
Protein-protein interaction (PPI) network construction
To study the association between putative phytocompound targets and breast cancer-related hub genes, a protein-protein interaction (PPI) network was constructed using the Search Tool STRING (http://www.string-db.org/) with a threshold of >0.4. (minimum confidence) 33. On a histogram, the statistical distribution of the 30 most frequent target genes was shown. Cytoscape (3.7.1) program was used to display molecular-interaction networks 33,34.
Kyoto Encyclopaedia of Genes and Genomes (KEGG) and Gene Ontology (GO) Enrichment and Network Analyses of the Target Proteins
GO is regarded as an essential bioinformatics technique for identifying genes and analyzing their biological processes 35,36. The Kyoto Encyclopaedia of Genes and Genomes (KEGG) database evaluates the complex functions and biological systems of high-throughput sequencing-generated molecular data. KEGG includes genetic, chemical, and system function data 37. Shiny GO, a web-based platform, was used for KEGG and GO analysis, which was then applied to examine the activities of the target proteins 38.
Compound prescription-active component-disease target gene interaction network analysis
A network of links between prescription-active component-disease-target gene-pathway was constructed using Cytoscape (version 3.8.1). The word "node" refers to the drug, the active component, the disease, the target gene, and the pathways within the framework of the network. The link between the previously stated nodes is referred to as "edge." Following an examination of the quality indicators by degree, screening candidates with degrees above the average were selected from all active network components. When performing network research, the degree of a node's significance is the simplest metric to use.
In-silico drug-likeness and toxicity predictions
In silico drug likeness and toxicity of top hit compounds in the database based on was carried out using SwissADME web browser (http://www.swissdme.com) 39. Drug-likeness and toxicity filtering was based on Lipinski's rule of five 40. For example, constituents with predicted oral bioavailability (OB) ≥ 30 were considered active. Constituents that satisfied less than three criteria were considered inactive.
Molecular docking studies
The 3D structure of nine phytocompounds were retrieved from the PubChem data base and performed the docking with breast cancer hub genes such as (AKT-1, TNF, SRC and EGFR) identified by PPI network map. using AutoDock vina programme 41. The crystal structure of breast cancer targets obtained from the RCSB Protein Data Bank (https://www.pdb.org). To modify the target proteins by removing water molecules adding and kollman charges and polar hydrogen atoms using PyMol (version 1.7.2.1) programme. After that both target and receptor molecules were saved in pdbqt format. Molecular docking was performed within a grid box of particular dimensions and spacing. Docking studies of the protein–ligand complex were carried out following the Lamarckian Genetic Algorithm (LGA).
Molecular dynamics simulation (MD) studies
Molecular dynamic (MD) simulations investigations were carried out on dock complex with minimum energy using Desmond 2020.1 tool from Schrödinger, LLC programme 42. This programme employed the SPC water molecules and the OPLS-2005 force field 43-45. In MD simulations, Sodium ions were supplied to the system in order to neutralize the charge, and 0.15M of NaCl solutions were added to replicate the physiological environment. To retrain the system over the peiminine with CDK2 complex, the system was initially equilibrated using NVT ensemble for 100 picoseconds (ps). This was followed by a 12-ps NPT ensemble short run equilibration and minimization. The Nose Hoover chain approach 46 was used to build up the NPT ensemble, which was maintained throughout simulations at a constant temperature of 27 ºC, pressure of 1 bar and relaxation time of 1.0 ps. In the simulation experiment, a 2-fs time step was used. A 12-ns NPT ensemble run was employed to perform a rapid equilibration and reduction following the previous phase. The NPT ensemble was assembled using the Nose–Hoover chain coupling method 47 and operated at 27 °C for 1.0 ps under a pressure of 1 bar for the duration of the investigation. For pressure regulation, the Martyna–Tuckerman–Klein barostat method with a 2 ps relaxation time was adopted. Long-range electrostatic interactions were calculated using Ewald's particle mesh method, with the radius for coulomb interactions fixed at 9 nm. Each trajectory's bonded forces were computed using the RESPA integrator with a 2-fs time step. Using metrics such as the root mean square deviation (RMSD), gyroradius, root mean square fluctuation (RMSF), number of hydrogen atoms (H-bonds), and solvent accessible surface area (SASA), calculations were performed to track the stability of MD simulations 48.
In vitro cytotoxicity assay
Cell lines and culture conditions
Multiple breast cancer cell lines were used to test the in vitro anticancer properties of Fritillaria cirrhosa extracts (MCF-7, MDA-MB-231, MDA-MB-468, and 4T1). The National Centre for Cell Science (NCCS) Pune, India supplied the cells. For purposes of identification, the morphology of these cells was systematically assessed. To culture cells, Dulbecco's Modified Eagle's Medium was employed (DMEM; Thermo Fisher Scientific, Waltham, MA, United States). The medium was supplemented with 10% fetal bovine serum (Thermo Fisher Scientific, Waltham, MA, United States) and 1% penicillin-streptomycin (Thermo Fisher Scientific, Waltham, MA, United States). The cells were cultivated in a 37 °C CO2 incubator.
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) Assay
The MTT assay for determining the cytotoxic activity of extracts was done according to Keepers et al technique (1991). Cancer cells were extracted from culture flasks using trypsin, and trypan blue dye was used to determine their viability. The required number of wells in a 96-well plate were seeded with these cancer cells at a density of 3 x 103 cells per well in 100 ul of growth medium each well. The plate was incubated for 24 hours in a CO2 incubator at 5% CO2 and 37 °C. After 24 hours of incubation, the growth media was carefully removed and varied amounts of plant extracts generated in the growth medium were put to the plate (100µl per well; triplicate) and incubated. After a 4-hour incubation, the medium was discarded and fresh dye (4 mg MTT dye/10 ml growth media without FBS) was added to each well (100 µl/well). The plate was then incubated for another 4 hours. The formazan crystals in the wells were dissolved with 100 µl/well DMSO, and the optical density was measured at 540 nm using a Biotek Synergy HT, USA microplate reader.
Statistical analysis
Network interaction was evaluated via edge count. Docking data are presented as energy in kcal/mol. Interaction stability and fluctuations through MD simulation were analyzed by RMSD and RMSF. All experimental data were presented in mean ± SD. The IC50 was calculated using a linear regression curve by GraphPad ver 5 programme.