Search

Cymbopogon martinii is an aromatic crop cultivated for the production of its essential oil (EO) which has different applications. Bearing in mind that C. martinii EO (CMEO) has already been proved for high antibacterial potential the aim of this study was to formulate stable CMEO nanoemulsions, being capable to combat Enterococcus faecalis biofilm, especially within infected tooth’s root canal. Ten emulsions with variable CMEO content (2.5–10 % v/v) and Tween 80 (T80, 2.5–15 % v/v) were formulated (designated as ECMEO:T80) and screened for volume-weighted mean diameter (D4,3) and stability, using dynamic light scattering measurements. Chemical composition of stable nanoemulsions was monitored by UV–VIS and FTIR, while their antibacterial activity was estimated in microdilution assay. Antibiofilm properties of selected nanoemulsions were tested in vitro (cristal violet assay) and ex vivo (within root canals of the extracted teeth). Results showed that formulations containing 10 % of T80 and CMEO volume ≤ 6 %, as well as those having constant 2.5 % of CMEO and variable T80 volume (≤ 10%), namely E2.5:2.5, E2.5:5, E2.5:7.5, E2.5:10, E4:10, and E6:10, were stable and nanosized (D4,3 <100 nm). FTIR and UV–VIS analyses confirmed successful encapsulation of the CMEO by T80 and showed that nanoemulsification did not affect CMEO composition. Evaluation of antibacterial potential showed that the most efficient were E6:10, E2.5:2.5 and E4:10 (MIC values 0.37–1.97 mg mL−1). Analysis of dependency of determined MICs on mean diameter and CMEO volume showed that antibacterial potential increased with both parameters. E6:10, E2.5:2.5 and E4:10 also reduced in vitro biofilm (inhibitory range 17.6–58.4 %), as well as intracanal biofilm (reduction ~2Log CFU). Presented results suggest E6:10, E4:10 and E2.5:2.5 as the good candidates for further research.

U ovom radu ispitivana su etarska ulja i postdestilacioni ostatak (PDO) Juniperus communis L. GC-MS analiza ulja je pokazala dominantno učešće α-pinena, a LC-MS/MS je identifikovala hinsku kiselinu i rutin kao najzastupljenije u PDO. Bolja antioksidativna aktivnost PDO utvrđena je u TBA i naročito DPPH eseju (IC50 4,4 μg/mL), što potvrđuju i rezultati FRAP testa. Citotoksičnost je bila veća u slučaju ulja: IC50 vrednosti na ćelijskim linijama HT-29, HCT 116, A549 i MRC-5 bile su u opsegu 69-120 μg/mL. Efekat kombinacija oba derivata sa doksorubicinom na kancerskim A549 i normalnim MRC-5 ćelijama bio je sinergistički, naročito u slučaju A549. Citometrijska analiza i alkalni komet test su pokazali da PDO indukuje apoptozu, zaustavlja ćelijski ciklus i ima genotoksični efekat. MIK testom je utvrđeno da su Listeria monocytogenes i Aspergillus versicolor najosetljivije, posebno prema PDO (MIK 0,39 i 0,12 mg/mL). Sinergizam je uočen u slučaju tretmana listerije kombinacijama ulja/PDO i streptomicina/ampicilina/azitromicina, kao i Candida albicans kombinacijom PDO i bifonazola. Adhezija patogena na ćelije kolona u kulturi bila je inhibirana dejstvom PDO ili ulja, u slučaju listerije ili kandide. Etarska ulja kleke i čubra, primenjena u mikrodilucionim testovima odvojeno ili u kombinacijama, pokazala su dobar potencijal i postojanje sinergizma u slučaju primoizolata L. monocytogenes. Time kill test je potvrdio sinergizam i ukazao na veću osetljivost listerije u aerobnim nego hipoksičnim uslovima. Ulja primenjena na mariniranom mesu inhibirala su rast ukupnih aerobnih heterotrofa, enterobakterija, bakterija mlečne kiseline i inokulisane listerije. Uočeni citotoksični i antimikrobni efekat preporučuju derivate kleke za adjuvante koji pojačavaju aktivnost konvencionalnih lekova., In this work essential oils and post-distillation waste (PDW) of Juniperus communis L. were screened. GC-MS analysis pointed at α-pinene as dominant constituent of oils; LC-MS/MS identified quinic acid and rutin as the most prevalent in PDW. Higher antioxidativity of PDW was shown in TBA and especially DPPH assay (IC50 4.4 μg/mL), which is additionally confirmed by FRAP test. Oil induced higher cytotoxicity against HT-29, HCT 116, A549 and MRC-5 cells, with IC50 values ranging 69-120 μg/mL. Combinations of each derivative with doxorubicin, applied on cancer A549 and normal MRC-5 cells induced synergism especially pronounced in A549. Cytometric analysis and alkaline comet test showed that PDW induced apoptosis and cell cycle arrest, and was genotoxic. Microdilution assay pointed at Listeria monocytogenes and Aspergillus versicolor as the most sensitive, especially to PDW (MIC 0.39 and 0.12 mg/mL). Synergism was observed in the case of listeria treated with combinations of oil/PDW and streptomycin/ampicillin/azithromycin, as well as Candida albicans with a combination of PDW and bifonazole. In vitro adhesion of L. monocytogenes/C. albicans to colon cells was inhibited by PDW and oil, respectively. Additionaly, juniper and savory essential oils, applied in microdilution tests separately or in combinations, showed notable potential and synergism in the case of primoisolates of listeria. Time kill assay confirmed synergism and indicated a higher bacterial sensitivity under aerobic than hypoxic conditions. Oils applied to marinated meat inhibited the growth of total aerobic heterotrophs, enterobacteria, lactic acid bacteria and inoculated listeria. Observed cytotoxic and antimicrobial effect recommends juniper derivatives as adjuvants that enhance conventional drugs activity.