Chemical composition, In vitro anti-inflammatory, antimicrobial, and molecular docking studies of Landolphia dulcis essential oils

The ethnomedicinal relevance of Landolphia dulcis suggests the presence of bioactive phytochemicals with pharmacological potential. This study investigated the anti-inflammatory and antimicrobial activities of essential oils extracted from the leaves and stems of Landolphia dulcis, integrating In vitro bioassays with molecular docking simulations to validate therapeutic potential. Essential oils were obtained by hydrodistillation and characterized using gas chromatography–mass spectrometry (GC–MS). Anti-inflammatory activity was evaluated via the egg albumin denaturation assay, while antimicrobial effects were assessed using the agar well microdilution method. Molecular docking was performed with PyRx software against protein targets. GC–MS profiling of leaf oil revealed major constituents such as n-hexadecanoic acid (15.39%), phytol (10.76%), eucalyptol (6.52%), and caryophyllene oxide (4.87%). Stem oil showed 2-methyl-5-(1-methylethyl)-phenol (34.79%), caryophyllene oxide (33.38%), eucalyptol (7.04%), and thymol (2.50%). Stem oil demonstrated stronger anti-inflammatory activity (72.85% inhibition of albumin denaturation at 2% concentration) compared to leaf oil (63.48%), approaching the efficacy of drug controls. Antimicrobial assays confirmed significant inhibition of pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, Bacillus subtilis, Klebsiella pneumoniae) and fungi (Candida albicans, Aspergillus niger, Penicillium notatum, Rhizopus stolonifer). Docking analysis showed that caryophyllene oxide and phytol bound strongly to COX-2 (binding affinities –6.4 and –6.3 kcal/mol), supporting their anti-inflammatory potential, while thymol and n-hexadecanoic acid interacted with DNA gyrase B (binding affinities –5.7 and –5.1 kcal/mol), indicating antimicrobial potential. In conclusion, Landolphia dulcis essential oils possess promising anti-inflammatory and antimicrobial properties, providing a foundation for the development of novel therapeutic agents.