Isolation and Characterization of Bioactive Compounds from Hedyotis diffusa Willd. and Evaluation of their Antimicrobial, Antioxidant, Cytotoxic and Nitric Oxide Inhibitory Activities

Hedyotis diffusa Willd. is traditionally used in Vietnamese and Chinese medicine for its therapeutic properties. This study aimed to explore the bioactive components of the ethyl acetate extract of Hedyotis diffusa Willd. and evaluate their potential antimicrobial, antioxidant and anticancer activities. The extract was collected using fractionated column chromatography and five compounds viz. cholestane, campesterol, stigmasterol, diosgenin and digitoxigenin were isolated and characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. The extract exhibited significant antimicrobial activity against bacteria (Bacteroides fragilis, Klebsiella pneumoniae, Staphylococcus aureus and Streptococcus pyogenes at 80 mg/mL) and fungi (Aspergillus flavus and Aspergillus parasiticus at 80 mg/mL) associated with liver diseases. The extract demonstrated inhibitory activity against nitric oxide (NO) production in LPS-stimulated RAW264.7 cells at 20 µg/mL with low cell death rates 37,12% and DPPH scavenging which may be attributed to its high phenolic content. These findings suggest that Hedyotis diffusa Willd. extract holds promise as a therapeutic agent for liver damage and cancer, potentially through mechanisms beyond antioxidant activity.