First Time Isolation Report of Bioactive Flavonoids From Water Hyacinth (Eichhornia crassipes) Flower Associated With...

Eichhornia crassipes (water hyacinth) is an invasive aquatic plant traditionally regarded as an environmental nuisance but increasingly recognized for its phytopharmacological potential.

This study is aimed at isolating, characterizing, and evaluating the pharmacological activities of bioactive compounds from the dichloromethane (DCM) fraction of the methanolic extract of E. crassipes flowers.

Compounds were isolated through chromatographic techniques and structurally elucidated using ¹H NMR. Pharmacological activities were assessed using the brine shrimp lethality bioassay for cytotoxicity, egg white-induced edema and human red blood cell membrane stabilization for anti-inflammatory effects, and oral glucose tolerance tests in mice for hypoglycemic activity. Molecular docking against NF-κB, TNF-α, EGFR, BCL-2, GLUT3, and α-amylase, along with ADMET and radar plot analyses, was performed to predict interactions, pharmacokinetics, and drug-likeness.

Five compounds were isolated: 4 ^',5,7-trihydroxyflavone or apigenin (Compound 1), 3 ^',4 ^',5,7-tetrahydroxyflavone or luteolin (Compound 2), 5,6,7,8,4 ^'-pentahydroxyflavone or nortangeretin (Compound 3), methyl 3,5-dihydroxy-4-methoxybenzoate (Compound 4), and 4-hydroxybenzoic acid (Compound 5). Both the crude methanolic extract (CME) and the DCM-soluble fraction (DSF) exhibited strong cytotoxic activity in the brine shrimp lethality assay (LC₅₀ < 2 μg/mL). The DSF further demonstrated potent membrane stabilization (72% protection at 100 μg/mL) and marked hypoglycemic effects. Also, the CME illustrates dose-dependent anti-inflammatory activity in the egg white-induced paw edema model (up to 38.96% inhibition at 600 mg/kg) and showed notable hypoglycemic effects in the oral glucose tolerance test in mice. Docking revealed strong binding affinities of flavonoids with key inflammatory and metabolic targets, outperforming reference drugs in several cases. ADMET profiling indicated favorable oral bioavailability, whereas the BOILED-Egg model confirmed efficient gastrointestinal absorption but limited blood-brain barrier penetration.

This first report of pure compound isolation from E. crassipes flowers highlights their multitarget pharmacological potential. The findings suggest that E. crassipes, often seen as an ecological burden, represents a sustainable reservoir of bioactive molecules with promising drug discovery applications.