Combined experimental and molecular docking investigation of a cyclodextrin-myrrh oil inclusion complex: implications for solubility and antibacterial activity.

Poor aqueous solubility limits the use of myrrh oil in antibacterial aqueous formulations. Here, a hexane extract of Commiphora myrrh resin (myrrh hexane extract- MHE), rich in sesquiterpenes, was encapsulated in hydroxypropyl-β-cyclodextrin (HP-β-CD) to form a water-soluble inclusion complex (HP-β-CD/MHE). GC-MS identified eight constituents, with curzerene (31.4%) dominant. Molecular docking showed favourable inclusion, with Glide scores up to - 2.83. The complex exhibited antioxidant activity (62 ± 6% DPPH scavenging at 20% w/v; IC50 ≈10% w/v), comparable to 10 µg/mL ascorbic acid, while HP-β-CD alone was inactive. Antibacterial assays using HP-β-CD/MHE showed concentration-dependent growth inhibition of Staphylococcus aureus and MRSA, but limited effect on Escherichia coli. ≥ 7.5% (w/v) inhibited all strains over 24 h. Furthermore, HP-β-CD/MHE attenuated the growth of gentamicin-resistant Acinetobacter baumannii and Enterococcus faecium by approximately 40% and 30%, respectively, relative to gentamicin-treated cultures, indicating activity against pathogens with reduced susceptibility to gentamicin. Biofilm formation by Staphylococcus aureus was inhibited by up to 100%. In co-culture, 10% HP-β-CD/MHE suppressed bacterial activity and maintained ∼ 92% stem-cell viability. These findings highlight improved dispersibility with retained bioactivity, supporting applications in alcohol-free antibacterial washes.