Thymol nanospheres as an effective anti-bacterial agent

Program of Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
International Journal of Pharmaceutics (Impact Factor: 3.65). 06/2012; 434(1-2):360-5. DOI: 10.1016/j.ijpharm.2012.06.017
Source: PubMed


Among thymol, carvacrol, citronellal, eugenol and terpinen-4-ol, thymol showed the highest antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Thymol was then encapsulated into water dispersible submicron sized ethylcellulose/methylcellulose spheres, attaining the relatively high thymol loading level of 43.53% (weight of encapsulated thymol to weight of the thymol-loaded spheres). When tested against the same three bacterial strains, the encapsulated thymol gave comparable minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC) values to the unencapsulated compound while mostly showing lower MIC and MBC values than the conventionally used preservative, methyl-p-hydroxybenzoate (methylparaben). The use of encapsulated thymol at 0.078, 0.156 and 0.625 mg ml(-1) (0.52, 1.04 and 4.16 mmol(-1), respectively) in cosmetic lotion formulations provided total suppression of viable E. coli, S. aureus and P. aeruginosa growth (all initially seeded at 10(5) cfu ml(-1)), respectively, over the three month test period, whereas unencapsulated thymol showed effective suppression for only 2-4 weeks. Effective bacterial suppression by encapsulated thymol was also observed when used in cream and aqueous gel cosmetic formulations.

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    • "Accordingly, lots of attention has been focused on development of new materials and technologies for scaffolds fabrication [5] [6]. Semi-crystalline poly(-caprolactone) (PCL) has been attractive for fabrication of long term degradable implants with tailorable degradation natural antimicrobial [48] [49] [50] and antioxidant agent [51] [52] with high efficiency in the treatment of inflammatory processes and wound healing [53]. It was proven that thymol efficiently inhibit growth of oral pathogens in the mouth and may reduce dental caries [54] [55], whereby thymol based varnishes has been proven to delay bacterial colonization and the development of biofilm [56]. "
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    ABSTRACT: The potential of supercritical carbon dioxide (scCO2) processing of polycaprolactone (PCL) and polycaprolactone-hydroxyapatite (PCL-HA) composites for obtaining functional porous scaffolds at moderate temperatures (35–40 °C) was analyzed and quantified. The effect of scCO2 sorption kinetics on the swelling, foam morphology and thermal behavior of the PCL and PCL-HA composites was studied. Sorption isotherms were determined using magnetic suspension balance at 10–30 MPa and 35–40 °C. Influence of the pressure, HA amount (10–20%) and procedure for HA powder preparation on the sorption kinetics was discussed. Supercritical solvent impregnation (SSI) of PCL and PCL-HA with thymol was investigated as environmentally friendly way to produce functional scaffolds with controlled microstructure. Moderately high pressures (13–17 MPa) and 10% of HA were proven to be favorable for creation of the PCL scaffolds with satisfying foam microstructure (mean pore size ∼200–300 μm), filler distribution and thymol impregnation yields (12–18%). This was due to the satisfactory high scCO2 solubility (0.25–0.30 g/g) and mass transfer rate (∼10−10 m2/s) in the polymer phase as well as its great plasticizing effect (−ΔTm = 26.4–27.4 °C). Higher saturation of the polymer phase with scCO2 (0.30–0.55 g/g), filler amount (20%) and thymol solubility in scCO2 (>5.5 g/kg) at pressures above 20 MPa resulted in decreased mass transfer rate and SSI efficiency.
    Journal of Supercritical Fluids The 07/2015; DOI:10.1016/j.supflu.2015.07.001 · 2.37 Impact Factor
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    • "Thymol (THY) and carvacrol (CARV), are plant monoterpene phenols that show significant biological activities including anticancer [1], antibacterial [2] [3], antiviral [4], antifungal [5], antioxidant [6] and anti inflammatory [7] activities. THY and CARV are consequently widely studied [1] [8]. Although the infections caused by non-albicans Candida species are on the rise, Candida albicans is still the most common fungal pathogen. "
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    ABSTRACT: Thymol and carvacrol from the class of monoterpene phenols are one of the most potent plant essential oil components possessing antimicrobial effects. Known for their wide bioactive spectrum, these positional isomers of isopropyl cresol deplete ergosterol content, compromise membrane permeability, block efflux pumps and restore antifungal susceptibility to fluconazole in resistant Candida strains. Exposure to these natural compounds induces a cascade of stress responses, which are important to comprehend their microbicidal mechanisms. This study evaluates the antioxidant defense response to lower concentrations of thymol and carvacrol in Candida albicans. The antioxidant defense responses in C. albicans are important for developmental mechanisms pertaining to resistance against the immune system, infection establishment and drug resistance. In this view, primary and secondary antioxidant defense enzymes, and oxidative stress markers including glutathione and lipid peroxidation were determined in C. albicans cells exposed to lower concentrations of thymol and carvacrol. These compounds were found to induce oxidative stress and compromised the antioxidant defense system in C. albicans at lower concentrations. This study helps in understanding the ‘in cell’ antifungal mechanisms of natural monoterpene phenols originating from oxidative stress. Thymol and carvacrol induced membrane deterioration reported earlier, is further explained as a result of toxic radical cascade mediated by lipid peroxidation. Findings reinforce the observed toxic oxidizing effects of these compounds as a consequence of direct damage to antioxidant components and not to their genetic manipulations.
    Microbial Pathogenesis 02/2015; 80. DOI:10.1016/j.micpath.2015.02.004 · 1.79 Impact Factor
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    • "Both carvacol and thymol are commonly used as germicides and antiseptics in oral disinfectants and anesthetics as well as in cosmetics (Botelho et al., 2007). However, both compounds show bactericidal activities against other pathogenic bacteria (Nostro et al., 2012; Wattanasatcha et al., 2012). S. annua was found to contain alkaloid (1.25%) and saponin (1.30%), where the saponin at extract concentration of 5 mg/kg resulted in maintaining normal bloodglucose levels when orally administered to diabetic mice. "
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    ABSTRACT: Halophyte species of United Arab Emirates are a source of unique active phytochemicals, potentially due to the extreme environmental conditions under which the plants grow in the UAE. These phytochemicals make the native halophytes possibly interesting crops for biorefining, where biofuel production is combined with the production of value added chemicals, improving the economic feasibility of both process. Phytochemicals found in these species are widely recognized and researched as potential pharmaceutical and nutraceutical products. We reviewed the literature for secondary metabolites from species from the following halophyte families: Aizoaceae, Amaranthaceae (incl. Chenopodiaceae), Avicenniaceae, Zygophyllaceae. The review revealed that plant species belonging to these families contain valuable phytochemicals, such as fatty acids, terpenoids, flavonoids, alkaloids, steroids, tannins, saponins, quinones and coumarins, many of which have been reported to have therapeutic effects in humans.
    Emirates Journal of Food and Agriculture 12/2014; 26. DOI:10.9755/ejfa.v26i12.19104 · 0.31 Impact Factor
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