Anti-Inflammatory and Antimicrobial Activities of Extracts Developed from Symphytum officinale Leaves, Flowers, and Roots: Experimental Evaluation and Molecular Docking Study
Abstract
Symphytum officinale L. is a traditional medicinal plant widely used for wound healing and bone regeneration; however, comparative studies evaluating the biological activities of extracts prepared from different plant organs remain limited. The present study compared the antimicrobial and anti-inflammatory activities of organ-specific S. officinale extracts and investigated their potential molecular mechanisms of bioactivities using molecular docking. Antimicrobial activity was evaluated against six bacterial reference strains by broth serial dilution, whereas anti-inflammatory activity was assessed in a serotonin-induced paw oedema model in rats together with the determination of serum prostaglandin E2 (PGE2), tumour necrosis factor-α (TNF-α), and nitrotyrosine levels. Molecular docking was performed against bacterial peptide deformylases, cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX). The 40% ethanolic leaf extract (S-7) and 70% ethanolic flower extract (S-13) exhibited the broadest antimicrobial spectrum, with pronounced activity against S. aureus, E. faecalis, E. coli, and L. monocytogenes. The 70% ethanolic leaf extract (S-8) demonstrated the strongest early anti-exudative activity (47.50%), whereas the 70% ethanolic flower extract (S-13) most effectively reduced PGE2, TNF-α, and nitrotyrosine levels. Molecular docking suggested that kaempferol-3-O-glucoside may be the principal contributor to antimicrobial activity through interactions with bacterial peptide deformylases, while hyperoside, isoquercitrin, and rosmarinic acid exhibited favourable interactions with COX-2 and 5-LOX, indicating their key role in exerting anti-inflammatory effects. These findings demonstrate pronounced organ-specific pharmacological differences among S. officinale extracts and identify hydroethanolic leaf, flower, and root extracts as promising candidates for further development as multitarget wound-healing phytopharmaceuticals.