Antibacterial and Antiproliferative Properties of Portulaca oleracea Essential Oil and its Targeted Delivery to MCF-7 Cells via Spermine-PLA-PEG-FA Nanocapsules

Abstract

Portulaca oleracea essential oil is plant-derived product with documented antimicrobial and antiproliferative activities. Its clinical use is limited by poor water solubility, chemical instability, and lack of targeting. Encapsulation in polymeric nanocarriers can enhance solubility, stability, and selective delivery. This study investigated the antibacterial activity of P. oleracea essential oil against Staphylococcus aureus and Escherichia coli, and its antiproliferative effects on human breast cancer (MCF-7) cells using folic acid-modified spermine-polylactic acid-polyethylene glycol (Spermine-PLA-PEG-FA) nanocapsules. Gas chromatography-mass spectrometry (GC-MS) identified major components such as -pinene, limonene, and phytol. The essential oil and quercetin were co-encapsulated in the nanocapsules. Characterization was conducted by proton nuclear magnetic resonance spectroscopy ({superscript 1}H-NMR), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential thermogravimetric analysis (DTG), and transmission electron microscopy (TEM). Antibacterial properties were assessed using disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Antioxidant capacity was measured via 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Nanocapsules had spherical shape, size of 115-237 nm, and pH-responsive release. Quercetin-loaded nanocapsules induced apoptosis in MCF-7 cells with an IC of 11.21 mg/{micro}l. This delivery system improved the antibacterial and anticancer efficacy of P. oleracea essential oil. HighlightsO_LIThe presence of medicinal, antibacterial and anti-proliferative compounds in Portulaca oleracea essential oil controls the growth of bacteria (both gram-positive and gram-negative strains), especially Staphylococcus aureus bacteria, which are representative of gram-positive bacteria. C_LIO_LIEncapsulating P. oleracea essential oil in Spermin-PLA-PEG-FA copolymer nanoparticles prevented its oxidation and destruction in free conditions without a polymer coating. C_LIO_LIThe use of folic acid as a cell marker in the copolymer nanoparticle structure led to the identification of MCF-7 cancer cells by the nanoparticle/plant essential oil complex. This action increased the efficiency of the essential oil-targeted transfer system. C_LIO_LIThe presence of compounds such as resveratrol and lycopene in P. oleracea essential oil has increased its antioxidant properties. C_LI