Phytochemical, antioxidant, and antimicrobial properties of Bellardia trixago methanol and ethanol extracts: insights from ADMET and molecular docking approaches

This study investigates the antioxidant, antimicrobial, and phytochemical properties of ethanol and methanol extracts derived from Bellardia trixago flowers alongside molecular docking and pharmacokinetic assessments of stigmasterol, a key bioactive compound. The antioxidant activities of the ethanol and methanol extracts were determined, with the methanol extract demonstrating higher activity, 0.370 +/- 0.002 mg/mL, compared to the ethanol extract, 0.95 +/- 0.09 mg/mL. The total phenolic content of the ethanol extract was 79.14 +/- 2.30 mg GAE/g extract DW, and its flavonoid content was 244.31 +/- 12.51 mg QE/g extract DW. The methanol extract contained a lower phenolic content of 51.50 +/- 1.43 mg GAE/g extract DW but a higher flavonoid content of 251.67 +/- 6.68 mg QE/g extract DW. The ethanol extract exhibited a superior iron chelation capacity of 8.21 +/- 0.09 mg/mL relative to the methanol extract of 6.68 +/- 0.28 mg/mL. Antimicrobial assays demonstrated that both extracts exhibited strong bactericidal and bacteriostatic effects, with MIC values ranging from < 0.39 mg/mL to > 125 mg/mL. The highest antimicrobial activity was observed against Bacillus cereus NRRL B-3711. Phytochemical analysis identified 25 compounds in the methanol extract and 20 in the ethanol extract. Stigmasterol was the major constituent in both extracts, accounting for 26.51% in ethanol and 12.65% in methanol. Molecular docking studies of stigmasterol revealed strong binding affinities with several protein targets, including Candida albicans Complex III2 (-8.7 kcal/mol), Escherichia coli HipBST (-7.2 kcal/mol), and the ribosomal subunit of Staphylococcus aureus (-7.0 kcal/mol). These interactions highlight stigmasterol's potential role in modulating bacterial and fungal protein functions, emphasising the potential therapeutic applications of B. trixago, particularly in antimicrobial and antioxidant contexts.