The anti MRSA biofilm activity of Thymus vulgaris essential oil in nanovesicles.
Phytomedicine
; 57: 339-351, 2019 Apr.
Article
em En
| MEDLINE
| ID: mdl-30826631
ABSTRACT
BACKGROUND:
Thymus vulgaris essential oil (T) could be an alternative to classical antibiotics against bacterial biofilms, which show increased tolerance to antibiotics and host defence systems and contribute to the persistence of chronic bacterial infections.HYPOTHESIS:
A nanovesicular formulation of T may chemically protect the structure and relative composition of its multiple components, potentially improving its antibacterial and antibiofilm activity. STUDYDESIGN:
We prepared and structurally characterized T in two types of nanovesicles nanoliposomes (L80-T) made of Soybean phosphatidylcholine (SPC) and Polysorbate 80 (P80) [SPCP80T 10.750.3 ww], and nanoarchaeosomes (A80-T) made of SPC, P80 and total polar archaeolipids (TPA) extracted from archaebacteria Halorubrum tebenquichense [SPCTPAP80T 0.50.50.750.7 ww]. We determined the macrophage cytotoxicity and the antibacterial activity against Staphylococcus aureus ATCC 25,923 and four MRSA clinical strains.RESULTS:
L80-T (Z potential -4.1⯱â¯0.6â¯mV, â¼ 115â¯nm, â¼ 22â¯mg/ml T) and A80-T (Z potential -6.6⯱â¯1.5â¯mV, â¼ 130â¯nm, â¼ 42â¯mg/ml T) were colloidally and chemically stable, maintaining size, PDI, Z potential and T concentration for at least 90 days. While MIC90 of L80-T wasâ¯>â¯4â¯mg/ml T, MIC90 of A80-T was 2â¯mg/ml T for all S. aureus strains. The antibiofilm formation activity was maximal for A80-T, while L80-T did not inhibit biofilm formation compared to untreated control. A80-T significantly decreased the biomass of preformed biofilms of S. aureus ATCC 25,923 strain and of 3 of the 4 clinical MRSA isolates at 4â¯mg/ml T. It was found that the viability of J774A.1 macrophages was decreased significantly upon 24â¯h incubation with A80-T, L80-T and T emulsion at 0.4â¯mg/ml T. These results show that from 0.4â¯mg/ml T, a value lower than MIC90 and the one displaying antibiofilm activity, with independence of its formulation, T significantly decreased the macrophages viability.CONCLUSION:
Overall, because of its lower MIC90 against planktonic bacteria, higher antibiofilm formation capacity and stability during storage, A80-T resulted better antibacterial agent than T emulsion and L80-T. These results open new avenues to explode the A80-T antimicrobial intracellular activity.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Óleos Voláteis
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Thymus (Planta)
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Staphylococcus aureus Resistente à Meticilina
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Antibacterianos
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article