EO Concentration Research Articles

The Effect of Nanocomposite Edible Coating Enriched with Foeniculum vulgare Essential Oil on the Shelf Life of Oncorhynchus mykiss Fish Fillets during the Storage

ABSTRACT In this study, the antioxidant and antimicrobial effect of fennel essential oil in different concentrations of 1%, 1.5%, and 2% (W/V) with three types of nanocoating of basil seed gum, Lepidium perfoliatum, and their combination was examined for extending the life of fish meat. The amount of phenolic compounds for fennel was 80.59 mg g−1. The antioxidant activity of EO was assessed by DPPH and beta-carotene in different concentrations and an increasing trend for antioxidant properties was observed with increasing the EO concentration. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The size of the prepared nanocoatings was in the range of 270.80 to 473.21 nm and the zeta potential was negative for all nanocoatings. Fish meat samples were stored at 4°C for 28 days and peroxide value, thiobarbituric acid, S. aureus, E. coli and P. aeruginosa counts, pH, total volatile basic nitrogen (TVN-B), and color changes were measured at 7 day intervals. The use of nanotechnology led to the improvement of antioxidant and antimicrobial properties of coatings. According to the results, the nanocoating of BSG-LPSG containing 2% of fennel EO can be used in meat packaging factories.

Formulation, Characterization and Evaluation of Encapsulated Bioherbicide on Echinochloa cruss galli and Phalaris minor

Weeds management under organic agriculture demands organic herbicides / bioherbicides.to address this issue an experiment was conducted in Centre of Environment Sciences and Technology, Central University of Punjab, Bathinda to study the effects of different concentration and bioassay of encapsulated essential oil extracted (EOs) from Callistemon viminalis on Echinochloa cruss galli and Phalaris minor under lab conditions. Encapsulation efficiency of gum arabic and maltodextrin (GAMD) EOs increased from 26 to 31% for 4 to 8% of EOs concentration. The sizes of all the particles were found in the range of 1-10 μm. The reduced size in case of EOs loaded GAMD-EOs encapsulates may be due to the application of spray drying method used during the preparation. Maximum germination inhibition was observed with P. minor as compared to the E. crus-galli L. The probable reason behind this may be the relatively smooth seed coat, smaller weight to volume ratio of P. minor as compared to the E. crus-galli L. Among all the treatments basal application of encapsulates with 8 % essential oil was found more lethal and result in maximum phyto-toxicity by registering less shoot length and root length and fresh biomass weight. Also, the individual constituents of the EOs can be explored for their use as herbicides and then their encapsulated formulations can be used for scale up in the field conditions.

Antifungal effects of Curcuma longa L. essential oil against pathogenic strains isolated from indoor air

Curcuma longa L. essential oil can be considered a natural product with strong antifungal activity due to the fungicidal and fungistatic effect. It can be used for the aeromycological control of premises where food is prepared. It is important to monitor air quality in food production facilities to achieve safe food. The objective of this work was to evaluate the antifungal activity of C. longa essential oil on potentially pathogenic and biodegradable strains isolated from the indoor of the food industry. A suspension of 106 spores/mL of the strains Aspergillus flavus, Penicillium brevicompactum and Cladosporium cladosporioides was prepared. Two natural biocides (C. longa essential oil and Cuban propolis) and two synthetic ones (antiseptic detergent and Tween 20) at different concentrations (0, 0.001, 0.1 and 1.0% v/v) were evaluated. The superficial growth of the mycelium (cm) and the germination inhibition (%) were the response variables. In addition, the minimum inhibitory concentration (MIC) of EO was determined by radial growth total inhibition (IRG) and partial sporulation inhibition (PIS). A. flavus colony diameter was decrease inversely proportional to the concentrations, and at 1% v/v it reduced more than three times its diameter, being selected as MIC since it caused IRG and PIS. Germination inhibition of the spores of the three strains was observed in relation directly proportional to the concentration of the four biocides. All spores with values similar to antiseptic detergent were inhibited by the essential oil at MIC (1%) between 41 and 55%

Tetradenia riparia (Lamiaceae) essential oil: an alternative to Rhipicephalus sanguineus

In Brazil, Rhipicephalus sanguineus resistance to some pyrethroids have been detected, motivating research on new phyto-insecticides such as essential oil from Tetradenia riparia leaves (EOL) and flower buds (EOFB). The essential oils were obtained by hydrodistillation (3h) and identified by GC/MS. In addition, a multivariate exploratory analysis was done to determine the analysis of the major compounds (PCA). The bioassays on R. sanguineus larvae were done by immersion test at different EO concentrations which ranged from 50,000 to 0.47 mg/mL (v/v). The action mechanism of EOs were determined by bioautographic method evaluating the inhibitory potential on the acetylcholinesterase enzyme. The EO yield in leaves was 0.29±0.22 (%) and in flower buds 0.38±0.17 (%). The class projections showed oxygenated sesquiterpenes (43.62%) and diterpenes (15.60%) in EOFB, and hydrocarbon sesquiterpenes (26.44%) and oxygenated monoterpenes (16.44%) in EOL. Four components presented a greater distancing of mass flow: fenchone (11.57 and 6.01 %), α-cadinol (12.21 and 13.69 %), 14-hidroxy-9-epi-caryophyllene (8.56 and 15.38 %), and caryophyllene oxide (1.32 and 4.50 %) in EOL and EOFB, respectively. The lethal concentrations (LCs) to kill R. sanguineus larvae were (LC50: 2.18±0.24 and LC99.9: 9.98±0.10 mg/mL) for EOL, and (LC50: 5.36±2.50 and LC99.9: 20.12±0.54 mg/mL) for EOFB. The action mechanism of EOs by bioautographic methods indicated an inhibition of 0.70 mg/mL (EOL) and 1.40 mg/mL (EOFB) on the acetylcholinesterase enzyme (AChE). Therefore, this species can be considered promising to be part of the chemical larvicides to control this ectoparasite

High concentration of the ester-linked ω-hydroxy ceramide increases the permeability in skin lipid model membranes

The ester-linked ω-hydroxy acyl chain linked to a sphingosine base referred to as CER EOS is essential for the skin barrier lipid organization. While the majority of the skin lipids form a dense, crystalline structure, associated with low permeability, the unsaturated moiety of CER EOS, (either the linoleate or the oleate chain) exists in a liquid phase at the skin's physiological temperature. Thus, the relationship between CER EOS and barrier function is not entirely comprehended. We studied the permeability and lipid organization in skin lipid models, gradually increasing in CER EOS concentration, mixed with non-hydroxy sphingosine-based ceramide (CER NS) in an equimolar ratio of CERs, cholesterol, and free fatty acids (FFAs) mimicking the ratio in the native skin. A significant increase in the orthorhombic-hexagonal phase transition temperature was recorded when CER EOS concentration was raised to 70 mol% of the total CER content and higher, rendering a higher fraction of lipids in the orthorhombic phase at the expense of the hexagonal phase at physiological temperature. The model's permeability did not differ when CER EOS concentration ranged between 10 and 30% but increased significantly at 70% and higher. Using CER EOS with a perdeuterated oleate chain, it was shown that the fraction of lipids in a liquid phase increased with CER EOS concentration, while the neighboring CERs and FFAs remained in a crystalline state. The increased fraction of the liquid phase therefore, had a stronger effect on permeability than the increased fraction of lipids forming an orthorhombic phase.

Rheological Behavior, Antimicrobial and Quorum Sensig Inhibition Study of an Argentinean Oregano Essential Oil Nanoemulsion.

In this study, Argentinean oregano essential oil (OEO) nanoemulsions (NEs) were developed. Four NEs were prepared: a control (CNE), EONE1 (10.6 mg EO/g NE), EONE2 (106 mg EO/ g NE), and EONE3 (160 mg EO/g NE) and tested for antimicrobial activity against Staphylococcus aureus ATCC 13565, Listeria monocytogenes Scott A, Pseudomonas aeruginosa ATCC 14213, and Escherichia coli O157:H7 using a broth microdilution assay and quorum sensing inhibition in a model using Chromobacterium violaceum ATCC 12472, where the production of violacein was quantified. The chemical composition of the EO was determined by gas chromatography–mass spectrometry. The average particle size (nm) and polydispersity index were monitored over 14 days at two different storage temperatures (4 and 23°C). A rheological behavior study was carried out using a dynamic shear rheometer, and flow curves, as well as viscoelastic properties, were determined. E. coli and L. monocytogenes were the most sensitive microorganisms to EONE (MIC of 2 and 5 mg/ml for EOEN3). Sub-MICs for NE were found at lower concentrations than those for pure EO. A significant reduction in violet pigment intensity and colorless coloration (p < 0.05) were observed at different NE concentrations concerning the control sample. The flow behavior index (n) decreased, and the consistency index (k) increased when the EO concentration was increased. CNE, EONE1, and EONE2 showed liquid-like behavior (G′ < G″) in the low-frequency region, whereas a solid-like behavior (G′ > G″) was observed in the high-frequency region, presenting a viscoelastic behavior, appearing as a wormlike micellar solution. For EONE3, a strong increase in both moduli was observed with increasing OEO concentration. The G′ was about one order of magnitude higher than the G″ over the whole frequency range, indicating the presence of a gel-like structure. The incorporation of EOs into an NE increased their stability, lowering the particle size, leading to a wormlike micelle with higher viscosity. Moreover, this NE had good antimicrobial activity and novel quorum-sensing inhibition activity. The results of this study indicated that Argentinean OEO NE could be used in a food system as a natural and stable antimicrobial agent.

Chemical Composition and Efficacy of Ocimum basilicum L. Essential Oil against Stored Rice (Oryza sativa L.) Molds Sold in Ngaoundere (Cameroon)

The aimed of this study to evaluate the antifungal activity of essential oils of Ocimum basilicum L. on some fungi isolated from commercial rice sold in Cameroon. Fungal isolates were primarily identified based on morphological characteristics, while representative isolates were identified using PCR-based methods. Essential oils were extracted by hydro-distillation, chemical composition was analyzed by gas chromatography coupled with mass spectrometry (GC-MS) and antifungal activity against isolated fungi were assessed using the micro-atmospheric method. The percentage of frequency and abundance varied with the sample analyzed and the fungi detected. A total of 85 fungal isolates of eight genera including Aspergillus, Fusarium, Penicillium, Rhizopus, Cladosporum, Mucor Alternaria and Acremonium in decreasing order of predominance were identified. The most fungal species identified were Aspergillus flavus, A. fumgatis, A. niger, A. carbonarius, Fusarium oxysporum, F. graminarum, F. moniliforme, Penicillium citrinum, P. expansum, Rhizopus oryzea, Cladosporum sp, Mucor hiemalis, Alternaria solani, Acremonium murorum. More than 61% (A. flavus, A. niger, P. citrinum) and 44% (M. hiemalis, A. flavus, A. niger) of analyzed samples contain respectively aflatoxin B1, AFB1 (0 - 17.3 µg/kg) and ochratoxin A, OTA (0 - 5.2 µg/kg). Citrinin was not detected. The main compounds identified in O. basilicum EO are eugenol (30.6), linalool (29.5), cineole (14.4), Terpinen-4-ol (5.6), 2-norpinen (4.1), Cadinen (3.3), Limonen (2.4) and (E)-β-Ocimene (2.2). The O. basilicum EO exhibit antifungal activity with the MIC range from 750-2000 ppm. This activity varies with the strains and the concentration of EO. The increased prevalence of mycotoxigenic fungi in rice, a highly consumed food grain in Africa, poses serious health concerns to the general public. The O. basilicum EO can therefore be used as alternatives to synthetic pesticide in rice storage.

Application of Response Surface Methodology to Evaluate Photodynamic Inactivation Mediated by Eosin Y and 530 nm LED against Staphylococcus aureus.

Photodynamic antimicrobial chemotherapy (PAC) is an efficient tool for inactivating microorganisms. This technique is a good approach to inactivate the foodborne microorganisms, which are responsible for one of the major public health concerns worldwide—the foodborne diseases. In this work, response surface methodology (RSM) was used to evaluate the interaction of Eosin Y (EOS) concentration and irradiation time on Staphylococcus aureus counts and a sequence of designed experiments to model the combined effect of each factor on the response. A second-order polynomial empirical model was developed to describe the relationship between EOS concentration and irradiation time. The results showed that the derived model could predict the combined influences of these factors on S. aureus counts. The agreement between predictions and experimental observations (R2adj = 0.9159, p = 0.000034) was also observed. The significant terms in the model were the linear negative effect of photosensitizer (PS) concentration, followed by the linear negative effect of irradiation time, and the quadratic negative effect of PS concentration. The highest reductions in S. aureus counts were observed when applying a light dose of 9.98 J/cm2 (498 nM of EOS and 10 min. irradiation). The ability of the evaluated model to predict the photoinactivation of S. aureus was successfully validated. Therefore, the use of RSM combined with PAC is a promising approach to inactivate foodborne pathogens.

Modelling release mechanisms of cinnamon (Cinnamomum zeylanicum) essential oil encapsulated in alginate beads during vapor-phase application

Encapsulation efficiency of Cinnamomum zeylanicum essential oil (EO, at 5% v/v) in sodium alginate beads and its controlled release was determined. Composition of vapors generated by the beads was assessed by solid-phase microextraction. Water and EO released from the beads in the vapor phase were determined at 59% or 88% relative humidity at 4 °C or 25 °C. First and second order dynamic models appropriately described release mechanisms of water and EO, demonstrating Fickian behavior in both cases, in which diffusion mainly depends on EO concentration gradients. Encapsulation efficiency was 85.43% ± 4.97%, volatile components (cinnamaldehyde, caryophyllene, and α-caryophyllene) were detected in the vapor phase. Water and EO release rates were higher at the higher temperature, while a higher relative humidity led to lower water release but greater EO diffusion. Furthermore, enhanced antifungal (against Botrytis cinerea, Penicillium expansum, Alternaria alternata, or Colletotrichum gloeosporioides) activity of encapsulated EO was observed in vapor phase.

Synergistic effect of peppermint and garlic essential oil on fate of Kluyveromyces marxianus in Zucchini Bouranee

AbstractThe purpose of the study was to evaluate the inhibitory effect of garlic (GEO) and peppermint (PEO) essential oils on Kluyveromyces marxianus (K. marxianus) in zucchini bouranee and also to assess the product's functional physicochemical properties during storage. The results showed that the combined use of the GEO and PEO caused a faster decrease in the yeast count. The growth rate of K. marxianus reduced significantly with increasing the EOs concentration (p &lt; .05). No significant difference was found between amounts of the dry matter of the treatments until the 14th day. The syneresis percentages were significantly different between the treatments during storage. Meanwhile, the GEO treatments had a higher syneresis rate compared with the PEO treatments (p &lt; .05). The organoleptic assays showed that the GEO 0.05% treatment obtained the highest score. As a result, the antimicrobial properties of the EOs, especially GEO, could increase the zucchini bouranee shelf life.

What is the preferred concentration of ethanolamine oleate for sclerotherapy of oral vascular anomalies?

Background This study compared three different concentrations of EO (1.25%, 2.5% and 5%) for the treatment of oral vascular anomalies (OVAs). Material and Methods This was a retrospective comparative analysis of patients with OVAs treated with EO. Anomalies smaller than 20 mm were included. The patients were treated with 1.25% (G1), 2.5% (G2), and 5% (G3) and clinical data were obtained. The number of sessions, the final volume and dose of EO were statistically analyzed to verify effectiveness and safety of the treatment. The different concentrations of EO were compared considering the number of sessions, the final volume and total dose of EO. Analysis of covariance (ANCOVA) was used to evaluate the influence of covariates on the outcomes. A p-value < 0.05 was considered significant. Results Nineteen women and 11 men with a median age of 54 years were included. The OVAs were most frequent in the lip (n=14) and cheek (n=9). All lesions exhibited complete clinical healing within 28 days. Patients of G3 required fewer sessions than those of G2 (p=0.017), a lower final volume compared to the other groups (p<0.001), and a lower total dose than G1 (p<0.001). Patients of G1 used a lower total dose than G2 (p=0.003). Conclusions The concentration of 5% EO performed better than 1.25% and 2.5% for sclerotherapy of OVAs measuring up to 20 mm. This preliminary result should be the preferred concentration of EO to provide an effective and safe treatment of OVAs. Key words:Ethanolamine oleate, sclerotherapy, vascular malformations, hemangioma, oral mucosa.

Inclusion of a blend of copaiba, cashew nut shell and castor oil in the protein-energy supplement for grazing beef cattle improves rumen fermentation, nutrient intake and fibre digestibility

Context Essential oils are secondary plant compounds extracted from plants, with potential for the modulation of rumen fermentation. Aims Two experiments, namely one in vivo and another in vitro, were conducted to analyse the effects of a commercial blend of essential oils (EO; copaiba (Copaifera langsdorffii), cashew nut shell (Anacardium occidentale) and castor oil (Ricinus communis) and monensin as dietary feed additives in protein–energy supplements (PES) provided to grazing beef cattle, on ruminal fermentation, intake, total nutrient digestibility and protein dietary efficiency. Methods In the in vivo experiment, four entire Nellore bulls cannulated in the rumen (374 ± 15.66 kg; mean ± s.d.) were used in a 4 × 4 Latin-square design to evaluate the effects of EO concentration and monensin on voluntary intake, digestibility, and rumen and metabolic characteristics of grazing beef cattle provided with supplementation during the rainy season. Treatments were as follows: control (CON; PES without additives); monensin (MON; PES with inclusion of monensin at 20 mg/kg DM consumed); EO150 (PES with inclusion of EO at 150 mg/kg DM consumed); EO300 (PES with inclusion of EO at 300 mg/kg DM consumed). In the in vitro experiment, the effects EO150, EO300 and EO450, MON and CON on DM and neutral detergent-fibre (NDF) digestibility, and total gas production, were evaluated in four consecutive runs using a gas-production (GP) system. Key results In the in vivo experiment, DM intake, forage DM intake, crude protein intake and NDF intake were similar (P &amp;gt; 0.05) between EO150 and MON, but both were greater than those in EO300 and CON (P &amp;lt; 0.05). A lower EO concentration (EO150) increased (P &amp;lt; 0.05) NDF digestibility and improved nitrogen utilisation efficiency. In the in vitro experiment, the addition of MON and EO150 did not modify (P &amp;gt; 0.05) GP, DM and NDF digestibility compared with the control, but EO300 and EO450 decreased GP at 12 and 24 h and decreased DM and NDF digestibility at 48 h compared with the control, MON and EO150. Conclusions In vivo and in vitro results suggested that EO (copaiba oil, cashew nut shell and castor) at low doses (150 mg/kg DM) has the potential to improve ruminal fermentation in grazing beef cattle receiving supplements, but medium and high doses of EO can have adverse effects. Implications EO blends could be an alternative to MON for grazing beef cattle with access to supplements.

Adjuvant Treatment with Xiaoqinglong Formula for Bronchial Asthma in Acute Attack: A Systematic Review of Randomized Controlled Trials.

Background XQLF (Xiaoqinglong formula) is the most commonly used prescription of traditional Chinese medicine in the treatment of asthma. XQLF combined with western medicine has been used to treat bronchial asthma in more and more cases, and good results have been achieved. Therefore, this meta-analysis aimed to evaluate the adjuvant treatment of traditional Chinese medicine classic herbal formula XQLF with bronchial asthma in acute attack. Methods The following electronic databases were systematically searched from inception to April 2019: PubMed, EMBASE database, Cochrane Library, China National Knowledge Infrastructure (CNKI), WanFang, VIP Database for Chinese Technical Periodicals, and China Biology Medicine (CBM). Two reviewers searched these databases and independently evaluated all the eligible articles for inclusion. Stata 14.0 was used for data synthesis and analysis. Results A total of 33 RCTs (randomized controlled trials) including 2176 patients were enrolled. All of the patients in these studies were in the acute attack stage of asthma. We conducted subgroup analysis according to the duration of treatment, which was 14 days, 10 days, and 7 days, respectively. The overall results show that adjuvant treatment with XQLF significantly improve CER (clinical efficacy rate) (RR = 1.17; 95% CI, 1.14 to 1.21; P < 0.0001) and promote pulmonary function including FEV1 (WMD = 0.35; 95% CI, 0.27 to 0.43; P < 0.0001), PEF (SMD = 1.02; 95% CI, 0.49 to 1.55; P < 0.0001), and FVC (WMD = 0.51; 95% CI, 0.35 to 0.66; P < 0.0001). The adjuvant treatment of XQLF can also reduce serum IgE concentration (SMD = −1.39; 95% CI, 1.92 to −0.85; P < 0.0001) and serum EOS concentration at 14 days (WMD = −39.85; 95% CI, −56.20 to −23.49; P < 0.0001). Conclusion This study finally showed that XQLF has the auxiliary effect of improving the efficiency, promoting the lung function, and reducing the serum IgE in the treatment of acute attack asthma. This trial is registered with CRD42019133549.

Sage Essential Oil Improves the Effectiveness of Aloe vera Gel on Postharvest Quality of Tomato Fruit

Edible coating is extensively applied for fresh produce preservation. In the present study, Aloe vera gel (AV) alone or combined with sage essential oil (EO; 0.1% or 0.5%) was used as fruit edible coating in tomatoes. Following treatments, tomatoes were stored at 11 °C and 90% relative humidity (RH) up to 14 days and analyzed for quality maintenance compared with uncoated fruits (control). Results showed that both AV and EO decreased decay symptoms with more pronounced effects on low EO concentration (i.e., 0.1%). The application of 10% of AV coating decreased fruit ethylene emission while EO (0.1% and 0.5%) application increased ethylene emission and respiration rates. AV coating decreased acidity, β-carotene, lycopene content and maintained fruit firmness. High levels of EO (0.5%) increased weight loss but decreased fruits’ redness, chroma, total soluble solids, acidity, β-carotene and lycopene content. Total phenolic content and antioxidants maintained or increased during storage when treated with AV and/or EO. Low levels of EO (0.1%) maintained or improved fruit quality characteristics during storage, and this was mirrored by the sensory evaluation preference (including the AV application) and quality related attributes.

Control of Alternaria alternata Using Melaleuca Essential Oil (Melaleuca alternifolia)

Aims: This study aimed to evaluate the fungitoxic potential of melaleuca essential oil on the mycelial growth of Alternaria alternata under in vitro condition and the treatment of cowpea beans.&#x0D; Study Design: The experiments comprised completely randomized designs: Eleven treatments with five replicates on in vitro test; and six treatments with five replicates on in vivo test.&#x0D; Place and Duration of Study: The work was carried out at the Center for Agrifood Science and Technology of the Federal University of Campina Grande, Pombal, Brazil, since February 2018 to February 2019.&#x0D; Methodology: In the in vitro experiment, the essential oil was incorporated into the culture medium and poured into Petri dishes. The treatments consisted of different concentrations of the essential oil (0.0125, 0.025, 0.05, 0.1, 0.2, 0.25, 0.50, 0.75, and 1.0%), a negative control (0.0%), and a positive control (Thiram). Discs of culture medium with fungal mycelia were inoculated in the center of the plates and incubated for seven days at 27±2ºC. The percentage of mycelial growth inhibition (PGI) and the index of mycelial growth speed (IMGS) was calculated to verify the difference between treatments. In the in vivo experiment, the bean seeds were treated with different concentrations of EO (0.0, 0.2, 0.5, 1.0, and 5.0%), a negative control (0.0%), and positive control (Thiram). Seeds were inoculated with colonies of the fungus for 48 hours, and after that, we performed the seed sanity test.&#x0D; Results: Under in vitro conditions, all concentrations of melaleuca essential oil reduced the mycelial growth of A. alternata. The oil reached complete inhibition of fungal growth from 0.2% concentration and above. In the cowpea treatment, the essential oil had no significant control over the percentage of infected seeds.&#x0D; Conclusion: The melaleuca essential oil had a fungitoxic effect on the A. alternata under in vitro conditions. However, using the adopted methodology, on the cowpea bean seed treatment, the essential oil did not reduce the incidence of A. alternata.

Effects of Teucrium polium L. (Lamiaceae) essential oil and α-pinene on the detoxifying- and intermediary engaged enzymes of Ephestia kuehniella Zeller, 1879 (Lep.: Pyralidae)

This study investigated the effect of Teucrium polium L. essential oil (Tp EO) and α-pinene as its major component on the detoxifying- and intermediary-engaged enzymes of Ephestia kuehniella Zeller. Fourth instar larvae were separately fed on the treated artificial diets incorporated with LC50 concentration of Tp EO (4.91 μl ml-1) and α-pinene (10.66 μl ml-1). After three time intervals (24, 48, 72 hours), larval hemolymph was extracted to determine enzymatic activities. Activity of esterase, alanine and aspartate aminotransferases, aldolase, lactate dehydrogenase, and alkaline phosphatase were decreased in the treatments compared with the control. No significant differences were observed between some enzymes in the treated larvae highlighting their ineffectively role to detoxify and to metabolize Tp EO and α-pinene in the hemolyph of E. kuehniella larvae.

Bioinsecticide potential of Curcuma zedoaria rhizome essential oil

In this study the potential bioinseticide of the essential oil (OE) extracted from the rhizomes of the species Curcuma zedoaria (Zingiberaceae) was evaluated. The rhizomes were collected during dormancy (winter) and budding (summer). The EO was obtained by hydrodistillation (2h) and identified by GC/MS. In addition, a multivariate exploratory analysis was done to determine the analysis of the major compounds (PCA). The EO yield in dormancy was 0.61± 0.07 (%) and in budding 0.55 ± 0.08 (%). The bioassays on Aedes aegypti larvae and pupae were done by immersion test at different EO concentrations which ranged from 500.00 to 0.003 mg mL-1 (v/v). The results on the larvae and pupae indicated LC99.9 of (0.01 and 1.38 mg mL-1) for EO in dormancy, and (0.08 and 2.63 mg mL-1) for EO during budding, respectively. The action mechanism of EOs in both periods was determined by autobiographic method evaluating the inhibitory potential on the acetylcholinesterase enzyme, indicating greater inhibition of the EO enzyme during dormancy (0.039 mg mL-1) when compared to the EO during budding (0.156 mg mL-1). The projection representation of the EO chemical classes in both evaluated periods indicated that oxygenated sesquiterpenes are the major compound class (46.99% in dormancy) and (43.59% in budding). The projection of major chemical compounds of EOs presented three compounds with greater mass flow distancing: epicurzerenone (18.20% and 12.10%); 1.8 cineole (15.76% and 12.10%) and β-elemene (4.43 and 0.01%) that are found in greater amounts in the dormancy EO when compared to budding, respectively. These results corroborate with the greater potential on Ae. aegypti larvae and pupae found for the dormancy EO. The results are promising because they show in which vegetative cycle phase C. zedoaria EO presents greater bioinsecticide potential.

Isolation and characterization of Aeromonas sp. TXBc10 capable of high-efficiency degradation of octylphenol polyethoxylate from tannery wastewater

ABSTRACT Octylphenol polyethoxylate (OP n EO) is a potential endocrine-disrupting chemical. Biodegradation of OP n EO was investigated using the bacterium Aeromonas sp. TXBc10 isolated from the influent of tannery waste treatment plant in Hunan Province, China. The bacterium was capable of utilizing OP n EO as the sole source of carbon and energy while OP n EO was degraded under aerobic batch culture conditions. Microbial degradation of OP n EO was studied in batch experiments for optimization of environmental factors. The effect of initial OP n EO concentrations on the degradation was investigated between 100 and 1000 mg·L−1 and the results showed that the biodegradation process conformed to the first-order kinetic model. The optimum pH, temperature, salinity and size of inoculum for OP n EO degradation by Aeromonas sp. TXBc10 was found to be 8.0°C, 30°C, 2.5% and 2.0%, respectively. The major metabolites of OP n EO degradation were identified as short-chain octylphenol polyethoxylate without octylphenol by high-performance liquid chromatography – mass spectrometer, which indicated that sequential cleavage of single ethoxylate units to form OP n- 1EC might be the transformation mechanism of strain TXBc10. Considering that strain TXBc10 exhibits prominent advantage for biodegradation of OP n EO, it might serve as a promising candidate for in situ remediation of OP n EO and compounds with similar structure in tannery wastewater.

Cinnamon and clove essential oils to improve physical, thermal and antimicrobial properties of chitosan-gum arabic polyelectrolyte complexed films

Chitosan-gum arabic-based polyelectrolyte complexed films with cinnamon essential oil (CEO) and clove essential oil (CLO) were developed. The effect of EO concentrations, types and their combinations on the physical, thermal and antimicrobial properties of films were investigated. The results showed that the incorporation of EOs decreased the ζ-potential and viscosity, but increased the particle size of film-forming dispersions. Films incorporated with CEO and combined EOs exhibited better water barrier properties compared to those with CLO and single EO. Films containing CEO showed lower EO loss and higher thermal stability compared to those containing CLO, and the reason was attributed to the stronger interactions between chitosan, gum arabic and CEO. The combination of EOs resulted in higher retention and delayed release rate in food stimulant, resulting in stronger antimicrobial activities. The performance of films with the CEO and the combined EOs brought new formulation ideas in antimicrobial films.

Study of DNA-Binding Activity and Antibacterial Effect of Escitalopram Oxalate, an Extensively Prescribed Antidepressant.

Escitalopram oxalate (EO) is considered as one of the extensively prescribed antidepressant drug in Turkey and some other countries, therefore this research was aimed to study the interaction of the drug with DNA and study of the substance effect on bacterial growth. The absorption value of the drug solution at 238 nm was increased when DNA was added gradually to it and it showed hyperchromism effect. The value obtained for DNA binding constant (Kb) was 0.035 M -1. When we added the CuCl2 2H2O to the mixture, any breakage was not shown in double strand DNA in comparison with control DNA. In addition low concentration of EO couldn't protect DNA (0.5273 µmole bp) against Hydroxyl free radical (0.12 µmole) although it could protect the DNA when it was at the same or higher concentrations (0.5273, 5.273 and 252.73 µmole) than the DNA concentration. In addition, MIC of the drug for E.coli and Bacillus subtilis was almost 0.185 mM and 0.55 mM respectively. The E.coli strain was killed at concentrations 45, 15, 5 mM while the Bacillus subtilis was stable against all of the concentrations.