Unveiling the bactericidal effects of extracts and phytocompounds from Eichhornia crassipes (Mart.) Solms against methicillin-resistant Staphylococcus aureus (MRSA): An in vitro and in silico approach.

Abstract

Eichhornia crassipes (Mart.) Solms is used as a vegetable by the tribal communities of the Chittagong Hill Tracts in Bangladesh, where it has traditionally been employed to treat diarrhea, intestinal worms, digestive disorders, and hepatic conditions. However, its effects against methicillin-resistant Staphylococcus aureus (MRSA) remain unexplored. To assess the in vitro antibacterial potential of methanol, ethanol, and ethyl acetate extracts from the flowers and leaves of E. crassipes (MEECF, EEECF, EAEECF, MEECL, EEECL, and EAEECL) and to identify multi-target antibacterial phytocompounds in silico against MRSA. Preliminary phytochemical screening (PPS), Fourier-transform infrared spectroscopy (FT-IR), and gas chromatography-mass spectrometry (GC-MS) were used for phytochemical profiling of MEECF, EEECF, EAEECF, MEECL, EEECL, and EAEECL. The antimicrobial activity of the extracts was evaluated using in vitro agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Computational approaches were applied to identify multi-targeting agents from GC-MS-annotated phytocompounds. In phytochemical profiling, PPS revealed the diverse nature of the plant's compounds, while FT-IR identified various functional groups. GC-MS analysis metabolically annotated a total of 383 phytocompounds across all extracts. Molecular docking identified two key compounds: CID 4970 in MEECF and EEECF, and CID 615944 in MEECL. These hit phytocompounds exhibited strong multi-modal binding affinity toward β-lactamase and PBP2a. Further analysis demonstrated that CID 4970 and CID 615944 possessed favorable pharmacokinetic (PK) and drug-like properties without toxicity, making them promising candidates. Molecular dynamics simulation confirmed the binding stability and multi-modal inhibitory activity of CID 4970 and CID 615944 within the active sites of β-lactamase and PBP2a, reinforcing their potential as lead compounds for developing inhibitors against these proteins. All extracts demonstrated dose-dependent antibacterial activity in agar well diffusion, MIC, and MBC assays, supporting the in silico results. This study provides scientific validation for the traditional use of E. crassipes in treating bacterial infections and suggests that CID 4970 and CID 615944 could serve as promising candidates for developing novel anti-MRSA agents.