سنتز و مشخصه يابي امولسيون هاي پيكرينگ روغن ميخك و منتول پايدارشده با كيتوسان و بررسي اثر زيستي آن ها

Synthesis an‎d characterization of clove oil an‎d menthol Pickering emulsions stabilized with chitosan an‎d investigation of their biological effect

زيست فناوري

Controlling the growth of microorganisms in food an‎d pharmaceutical products is of great importance, particularly in light of the increasing preva‎lence of antimicrobial resistance. Plant essential oils, due to their diverse chemical constituents an‎d multiple mechanisms of action, represent promising natural alternatives for inhibiting bacterial an‎d fungal pathogens while minimizing the likelihood of resistance development. However, their volatility an‎d limited solubility in water necessitate the use of delivery systems capable of protecting the active compounds an‎d enabling controlled release. In this regard, Pickering emulsions, stabilized by solid particles, offer an innovative an‎d efficient solution. In this study, Pickering emulsions of clove essential oil an‎d menthol were formulated using different concentrations of chitosan nanoparticles an‎d eva‎luated for their physicochemical stability. Following synthesis, the emulsions were characterized using DLS, TEM, FTIR, an‎d rheological analysis. The loading efficiency of clove essential oil an‎d menthol in the Pickering system was assessed by HPLC, an‎d the chemical constituents of clove essential oil were identified by GC–MS. Biological eva‎luations included MTT cytotoxicity assays on fibroblast cells, agar well diffusion an‎d minimum inhibitory an‎d bactericidal concentration measurements against Escherichia coli an‎d Staphylococcus aureus, contact toxicity tests on solid media against Aspergillus niger, A. flavus, an‎d A. terreus, an‎d antioxidant analysis using DPPH an‎d ABTS assays. Stability an‎d rheological results demonstrated that the incorporation of menthol enhanced the stability of the Pickering emulsion system. The hydrodynamic diameter of the clove essential oil–menthol Pickering emulsion was determined to be approximately 109.8 nm. The MTT assay confirmed the biocompatibility of the formulated emulsions. Agar diffusion results revealed notable antibacterial activity, with inhibition zones of 15 mm an‎d 14.5 mm against S. aureus an‎d E. coli, respectively. For both microorganisms, the minimum bactericidal concentration was equal to the minimum inhibitory concentration, measured at 968.75 an‎d 1937.5 µg/mL for S. aureus an‎d E. coli, respectively. Antioxidant eva‎luation using ABTS an‎d DPPH demonstrated sustained release of active compounds over time, an‎d after two months, the emulsions exhibited strong free-radical scavenging effects (up to 90%) at concentrations of 50 an‎d 125 µg/mL. Overall, the findings suggest that this novel nanosystem has strong potential for application in various fields, including food preservation an‎d pharmaceutical formulations.

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