Synergism effect of the essential oil from Ocimum basilicum var. Maria Bonita and its major components with fluconazole and its influence on ergosterol biosynthesis

The aim of this study was to evaluate the activity of the EO and its major components of Ocimum basilicum var. Maria Bonita, a genetically improved cultivar, against the fluconazole sensitive and resistant strains of Candida albicans and Cryptococcus neoformans. Geraniol presented better results than the EO, with a low MIC (76 mg/mL against C. neoformans and 152 mg/mL against both Candida strains). The combination of EO, linalool, or geraniol with fluconazole enhanced their antifungal activity, especially against the resistant strain (MIC reduced to 156, 197, and 38 mg/mL, resp.). The ergosterol assay showed that subinhibitory concentrations of the substances were able to reduce the amount of sterol extracted. The substances tested were able to reduce the capsule size which suggests they have an important mechanism of action. Transmission electron microscopy demonstrated cell wall destruction of C. neoformans after treatment with subinhibitory concentrations. In C. albicans ultrastructure alterations such as irregularities in the membrane, presence of vesicles, and cell wall thickening were observed. The biofilm formation was inhibited in both C. albicans strains at MIC and twice MIC. These results provide further support for the use of O. basilicum EO and its major components as a potential source of antifungal agents

Effectiveness of methods for cleaning arch wire: an in vitro study

The aim of this study was to evaluate various methods of removing bacterial and fungus biofilm, to simulate orthodontic arch wires cleaning before reinsertion in the patients appliance. Rectangular Nickel Titanium (NiTi), Stainless Steel (SS) and Titanium Molybdenum (TMA) wires were divided into five groups, then contaminated with strains of Streptococcus mutans and Candida albicas.  Four segments of each group served as control and were not contaminated. Six cleanings methods were used to remove the biofilm: cotton roll and a chemical agent (chlorhexidine, sodium hypochlorite, 70% alcohol), cotton roll and  water, steel woll and immersion on enzymatic detergent. There was a control group not decontaminated Then wires were placed in broth separately, and after an incubation period the optical density (OD) was measured, observing whether there was microbial growth. A wire segment of each subgroup of SS 3M® was taken to the Scanning Electron Microscope (SEM) for visualization of the treatment response. The results were submitted to one-way ANOVA test and Tukey post-test. With the exception of 70% alcohol, the disinfection means behaved similarly regardless the type of wire. Two percent Chlorhexidine and 1% Sodium Hypochlorite totally removed the microorganisms while other agents left a high microbial concentration. Chemical cleaning is necessary to remove biofilm in orthodontic wires; 1% Sodium Hypochlorite and 2% Chlorhexidine are good disinfectants for this purpose

Growth inhibition of sulfate-reducing bacteria in produced water from the petroleum industry using essential oils

Strategies for the control of sulfate-reducing bacteria (SRB) in the oil industry involve the use of high concentrations of biocides, but these may induce bacterial resistance and/or be harmful to public health and the environment. Essential oils (EO) produced by plants inhibit the growth of different microorganisms and are a possible alternative for controlling SRB. We aimed to characterize the bacterial community of produced water obtained from a Brazilian petroleum facility using molecular methods, as well as to evaluate the antimicrobial activity of EO from different plants and their major components against Desulfovibrio alaskensis NCIMB 13491 and against SRB growth directly in the produced water. Denaturing gradient gel electrophoresis revealed the presence of the genera Pelobacter and Marinobacterium, Geotoga petraea, and the SRB Desulfoplanes formicivorans in our produced water samples. Sequencing of dsrA insert-containing clones confirmed the presence of sequences related to D. formicivorans. EO obtained from Citrus aurantifolia, Lippia alba LA44 and Cymbopogon citratus, as well as citral, linalool, eugenol and geraniol, greatly inhibited (minimum inhibitory concentration (MIC) = 78 µg/mL) the growth of D. alaskensis in a liquid medium. The same MIC was obtained directly in the produced water with EO from L. alba LA44 (containing 82% citral) and with pure citral. These findings may help to control detrimental bacteria in the oil industry

Aristolochia trilobata: Identification of the Anti-Inflammatory and Antinociceptive Effects

Aristolochia trilobata, popularly known as “mil-homens,” is widely used for treatment of stomach aches, colic, asthma, pulmonary diseases, diabetes, and skin affection. We evaluated the antinociceptive and anti-inflammatory activities of the essential oil (EO) and the main constituent, 6-methyl-5-hepten-2-yl acetate (sulcatyl acetate, SA). EO and SA (1, 10, and 100 mg/kg, p.o.) were evaluated using chemical (formalin-induced licking) and thermal (hot-plate) models of nociception or inflammation (carrageenan-induced cell migration into the subcutaneous air pouch, SAP). The mechanism of antinociceptive activity was evaluated using opioid, cholinergic receptor antagonists (naloxone and atropine), or nitric oxide synthase inhibitor (L-NAME). EO and SA presented a central antinociceptive effect (the hot-plate model). In formalin-induced licking response, higher doses of EO and SA also reduced 1st and 2nd phases. None of the antagonists and enzyme inhibitor reversed antinociceptive effects. EO and SA reduced the leukocyte migration into the SAP, and the cytokines tumor necrosis factor and interleukin-1 (TNF-α and IL-1β, respectively) produced in the exudate. Our results are indicative that EO and SA present peripheral and central antinociceptive and anti-inflammatory effects

Anti-Inflammatory Properties and Chemical Characterization of the Essential Oils of Four Citrus Species.

Citrus fruits have potential health-promoting properties and their essential oils have long been used in several applications. Due to biological effects described to some citrus species in this study our objectives were to analyze and compare the phytochemical composition and evaluate the anti-inflammatory effect of essential oils (EO) obtained from four different Citrus species. Mice were treated with EO obtained from C. limon, C. latifolia, C. aurantifolia or C. limonia (10 to 100 mg/kg, p.o.) and their anti-inflammatory effects were evaluated in chemical induced inflammation (formalin-induced licking response) and carrageenan-induced inflammation in the subcutaneous air pouch model. A possible antinociceptive effect was evaluated in the hot plate model. Phytochemical analyses indicated the presence of geranial, limonene, γ-terpinene and others. EOs from C. limon, C. aurantifolia and C. limonia exhibited anti-inflammatory effects by reducing cell migration, cytokine production and protein extravasation induced by carrageenan. These effects were also obtained with similar amounts of pure limonene. It was also observed that C. aurantifolia induced myelotoxicity in mice. Anti-inflammatory effect of C. limon and C. limonia is probably due to their large quantities of limonene, while the myelotoxicity observed with C. aurantifolia is most likely due to the high concentration of citral. Our results indicate that these EOs from C. limon, C. aurantifolia and C. limonia have a significant anti-inflammatory effect; however, care should be taken with C. aurantifolia

Effects of <i>C</i>. <i>limon</i>, <i>C</i>. <i>limonia</i> and <i>C</i>. <i>aurantifolia</i> essential oils on leukocyte migration into the subcutaneous air pouch (SAP).

<p>Animals were pretreated with different doses of the essential oils, dexamethasone (Dexa, 5 mg/kg, i.p.) or vehicle 1 h prior to carrageenan (1%) injection into the SAP. The results are presented as the mean ± S.D. (n = 10 per group) of cells (x 10⁶/mL) in the SAP. Statistical significance was calculated by ANOVA followed by Bonferroni's test. ^#P < 0.05 when comparing vehicle treated group that received carrageenan in the SAP with vehicle-treated animals that received PBS in SAP; *P < 0.05 when comparing essential oils-treated animals with that received carrageenan in the SAP with the group that only received carrageenan in the SAP.</p

Effects of <i>C</i>. <i>limon</i>, <i>C</i>. <i>limonia</i> and <i>C</i>. <i>aurantifolia</i> essential oils on the formalin-induced licking response in mice.

<p>Animals were pre-treated with oral doses (10, 30 or 100 mg/kg) of each essential oil, acetylsalicylic acid (ASA, 100 mg/kg) or vehicle. The results are presented as the mean ± S.D. (n = 7 per group) of the time that the animal spent licking the formalin-injected paw. Statistical significance was calculated by ANOVA followed by Bonferroni's test. *P < 0.05 when compared to vehicle-treated mice.</p

Effects of <i>C</i>. <i>limon</i>, <i>C</i>. <i>latifolia</i>, <i>C</i>. <i>limonia</i> and <i>C</i>. <i>aurantifolia</i> essential oils on the formalin-induced licking response in mice.

<p>Animals were pre-treated with oral doses of 100 mg/kg dose of each essential oil or vehicle. The results are presented as the mean ± S.D. (n = 6 per group) of the time that the animal spent licking the formalin-injected paw. Statistical significance was calculated by ANOVA followed by Bonferroni's test. *P < 0.05 when compared to vehicle-treated mice.</p

Effect of limonene on formalin-induced licking and SAP models.

<p>Animals were pretreated with various doses of limonene (5.5, 16.5 or 55 mg/kg) or vehicle 1 h prior to formalin (1%) or carrageenan (1%) injection. The results are presented as the mean ± S.D. (n = 6 per group). Statistical significance was calculated by ANOVA followed by Bonferroni's test. *P < 0.05 when comparing essential oils-treated animals with carrageenan injected in the SAP with the group that received carrageenan in the SAP.</p