Removal and toxicity evaluation of a diverse group of drugs from water by a cyclodextrin polymer/pulsed light system.

The presence of pharmaceutical compounds (PhCs) in the effluents of wastewater treatment plants (WWTPs) is an ecological concern. The issue could be alleviated by trapping those substances by cyclodextrin (CD) polymers or photolyzing them by pulsed light (PL). Consequently, a sequential CD polymer/PL system was tested for the removal of PhCs. Firstly, a survey detected the presence of recurrent PhCs in the effluents of local WWTPs. Then, pure water was spiked with 21 PhCs, 100 µg/L each one. The three-dimensional network provides amphiphilic features to the CD polymer that reduced the pollutant concentration by 77 %. Sorption involves a plead of physical and chemical mechanisms hindering the establishment of a general removal model for all compounds. The performed simulations hint that the retention capacity mainly correlates with the computed binding energies, so that theoretical models are revealed as valuable tools for further improvements. The complementary action of PL rose the elimination to 91 %. The polymer can be reused at least 10 times for ibuprofen (model compound) removal, and was able to eliminate the ecotoxicity of an ibuprofen solution. Therefore, this novel sequential CD polymer/PL process seems to be an efficient alternative to eliminate PhCs from wastewater.

A sustainable approach by using microalgae to minimize the eutrophication process of Mar Menor lagoon.

The present study evaluates the removal capacity of microalgae photobioreactors of environmental pollutants present in wastewater from the dry riverbed El Albujón, as a way to minimize the eutrophication process of the Mar Menor. Particularly, the capacity of four autochthonous microalgae consortia collected from different locations of the salty lagoon to remove emerging contaminants (simazine, atrazine, terbuthylazine, adenosine and ibuprofen), nitrates, and phosphates, was evaluated. Among the four microalgae consortia, consortium 1 was the best in terms of biomass productivity (0.11 g L-1 d-1) and specific growth rate (0.14 d-1), providing 100% removal of emerging contaminants (simazine, atrazine, terbuthylazine, adenosine and ibuprofen), and a maximal reduction and consumption of macronutrients, especially nitrates and phosphates, reaching levels below 28 mg L-1, that is, a decrease of 89.90 and 99.70% of nitrates and phosphates, respectively. Therefore, this consortium (Monoraphidium sp., Desmodesmus subspicatus, Nannochloris sp.) could be selected as a green filter for successful large-scale applications. This study is the first one that combines the successful removal of herbicides, ibuprofen and adenosine as emerging contaminants, and nitrate removal.

Bioavailable phytoprostanes and phytofurans from Gracilaria longissima have anti-inflammatory effects in endothelial cells.

BACKGROUND: An array of bioactive compounds with health-promoting effects has been described in several species of macroalgae. Among them, phytoprostanes (PhytoPs) and phytofurans (PhytoFs), both autoxidation products of α-linolenic acid, have been seen to exert immunomodulatory and antiinflammatory activities in vitro. The purpose of this study was to explore the bioaccesibility, bioavailability, and bioactivity of PhytoPs and PhytoFs obtained from the edible red algae Gracilaria longissima, and to gain insight into the anti-inflammatory activity of their bioavailable fraction in human endothelial cells. METHODS: The PhytoPs and PhytoFs profile and concentration of G. longissima were determined by UHPLC-QqQ-MS/MS. Algal samples were processed following a standardised digestion method including gastric, intestinal, and gastrointestinal digestion. The bioavailability of the PhytoPs and PhytoFs in the characterized fractions was assessed in a Caco-2 cell monolayer model of the intestinal barrier. The inflammation response of these prostaglandin-like compounds in human endothelial cells, after intestinal absorption, was investigated in vitro. RESULTS: Simulated digestions significantly reduced the concentration of PhytoPs and PhytoFs up to 1.17 and 0.42 µg per 100 g, respectively, on average, although permeability through the Caco-2 cell monolayer was high (up to 88.2 and 97.7%, on average, respectively). PhytoP and PhytoF-enriched extracts of raw algae impaired the expression of ICAM-1 and IL-6 inflammation markers. The inflammation markers progressed in contrast to the relative concentrations of bioactive oxylipins, suggesting pro- or anti-inflammatory activity on their part. In this aspect, the cross-reactivity of these compounds with diverse receptors, and their relative concentration could explain the diversity of the effects found in the current study. CONCLUSIONS: The results indicate that PhytoPs and PhytoFs display complex pharmacological profiles probably mediated through their different actions and affinities in the endothelium.

Protective effect of cyclodextrins on the quality parameters of roast preserved pepper.

Total phenolics (TP), vitamin C, antioxidant activity and colour of preserved peppers were evaluated at 4, 25 and 50 ℃ storage during 30-day intervals. Except for 4 ℃, TP decreased during storage at 25 ℃ and 50 ℃, being softer for fortified samples with ß-CDs. The protective effect was evident, since 50 ℃ samples containing ß-CDs exhibited lower TP loss (19%) than control samples (38%) for 5 months storage. A decrease in the vitamin C content was observed for both samples as time and temperature progressed. In samples stored at 50 ℃ the protective effect of ß-CD only was evident at the first month, since fortified samples showed lower vitamin C loss (10%) than control samples. The fortified samples with ß-CDs exhibited lowest antioxidant activity loss (40%) during 90-day storage at 50 ℃, than control samples (64%). The colour changes were in line with those observed for total phenolics and at the end of study, the presence of 1% ß-CDs delayed the darkening of samples at both (25 and 50 ℃) storage conditions.

Fluorimetric determination of sulphathiazole in honey by means the formation of CDs inclusion complexes.

The inclusion complex of sulphathiazole in ß-cyclodextrin has been investigated. A 1:2 stoichiometry of the complex was established and formation constants K2 (42.83 ± 3.27 M(-1)) and K1 (4.98 ± 0.36 M(-1)) were calculated by using the changes produced on the native fluorescence of the drug, when included on the hydrophobic cyclodextrin cavity. An enhancement in the fluorescence emission of sulphathiazole and protection of the drug against photochemical reactions has been attained upon inclusion. In solutions of ß-CD dual emission (458 nm) was noticed in STZ. Formation of the inclusion complex of STZ should result in dual emission, which is due to a twisted intramolecular charge transfer band (TICT). A fluorimetric method for the determination of sulphathiazole has been proposed and applied in honey without sample treatment. The optimized fluorimetric method showed detection and quantitation limits of 9.74 ng/g and 32.48 ng/g, respectively. Selectivity is high, showing no cross-reactivity to other chemically related antibiotics. The results obtained for blind honey samples (mean recovery 97%), were in good agreement with those obtained by liquid chromatography separation and mass spectrometry detection (LC-MS) (mean recovery 102%), showing that the proposed method might be used for the determination of sulphathiazole residues without expensive equipment.

Detection of chemical residues in tangerine juices by a duplex immunoassay.

A rapid duplex ELISA for the simultaneous determination of two of the most widely used organophosphorous insecticides in tangerine juices is described. To accomplish this aim, two individual enzyme-linked immunosorbent assays for chlorpyrifos and fenthion pesticides were integrated into one ELISA test. The strategy uses 96-well plates with specific wells coated with the corresponding haptenized conjugate. The optimized duplex ELISA was accomplished within 40 min achieving a detection limit of 0.20±0.04 µg/L and 0.50±0.06 µg/L, for chlorpyrifos and fenthion, respectively in tangerine juice samples. The determination of residues of both pesticides was carried out by simple sample dilution, without any extra sample clean-up procedure. Results of testing precision, stability, and selectivity demonstrated that the assay provided reliable analytical performances for the simultaneous determination of residues of chlorpyrifos and fenthion in fruit juice samples below the established European maximum residue limits (MRL). In addition, the accuracy and reliability of this duplex bioanalytical method is demonstrated by analyzing blind spiked juice samples and the results, correlated well with those achieved using a well-established GC/MS method (recoveries between 95% and 106%).

Antioxidant activity, color, carotenoids composition, minerals, vitamin C and sensory quality of organic and conventional mandarin juice, cv. Orogrande.

The effects of organic farming on antioxidant activity, CIE L*a*b* color, carotenoids composition, minerals contents, vitamin C and sensory quality of Orogrande mandarin juices were studied. Independent of the farming type, mandarin juices can be considered as good source of some important nutrients, such as potassium and antioxidant chemicals, for example, ß-cryptoxanthin. Organic farming of mandarin resulted in juices with higher antioxidant activity, total carotenoids concentrations, minerals (Ca, K and Fe) contents, vitamin C content, more appealing and intense orange color and better sensory quality. For instance, organic Orogrande juice contained significantly (p < 0.001) higher total carotenoids content (22.7 ± 0.3 mg/L) than conventional juice (15.7 ± 0.4 mg/L); a similar pattern was observed for the antioxidant activity, with values being 0.076±0.004 and 0.053 ± 0.003 mM Trolox m/L in organic and conventional juices, respectively. A trained panel stated that organic Orogrande juices had higher intensities of orange color, fresh mandarin and floral aromas than conventional juices.

Comparative study of different methods to measure antioxidant activity of resveratrol in the presence of cyclodextrins.

The antioxidant activity of resveratrol in the absence and presence of increasing concentrations of HP-ß-CDs was determined using three different methods: ORAC, ABTS and DPPH. The three methods were validated and compared for their linearity, precision and accuracy in measuring resveratrol antioxidant activity. The results indicated that the most sensitive method is the ORAC assay, which can measure the lowest resveratrol concentration (0.15-2 µM) with the highest precision. In the presence of increasing concentrations of HP-ß-CDs, the antioxidant activity of resveratrol was seen to increase when it was measured by the ORAC and ABTS assays. However, no increase was observed when the DPPH assay was used. With the ORAC assay, the antioxidant activity increased until all the resveratrol had been included in HP-ß-CDs (0.4 mM CDs), whereas in the case of ABTS assay the plateau in antioxidant activity was reached after 2 mM HP-ß-CDs, suggesting that the CDs interferences in the measurement method. When the DPPH assay was used, no effect was observed when increasing concentrations of HP-ß-CDs, indicating that in a methanolic medium resveratrol is free. Therefore, so this method cannot be used to measure the effect of resveratrol complexation with CDs on its antioxidant activity.

Detection of sulphathiazole in honey samples using a lateral flow immunoassay.

A lateral flow immunoassay (LFIA) was developed in the competitive reaction format and applied to test sulphathiazole (STZ) residues in honey samples. To prepare the assay test, a hapten conjugate and goat antirabbit antiserum as capture and control reagent, respectively, were dispensed on nitrocellulose membrane. Polyclonal antiserum against sulphathiazole was conjugated to colloidal gold nanoparticles and used as the detection reagent. The visual limit of detection (cut-off value) of the sulphathiazole LFIA was 15ng/g, reaching qualitative results within 10min. The assay was evaluated with STZ spiked honey samples from different geographical origins (n=25). The results were in good agreement with those obtained from liquid chromatography separation and mass spectroscopy detection (LC-MS), indicating that the LFIA test might be used as a qualitative method for the determination of sulphathiazole residues without expensive equipment. The test was also highly specific, showing no cross-reactivity to other chemically similar antibiotics. To our knowledge, this is the only work where a development of LFIA tests for the detection of sulphathiazole residues is performed.

Rosmarinic acid, a photo-protective agent against UV and other ionizing radiations.

Solar UV and other ionizing radiations cause a generation of reactive oxygen species, induce cellular DNA damage and alter skin homeostasis. The use of exogenous antioxidants is increasingly frequents, we attempt to demonstrate that a rosmarinic acid extract acts as photo-protector; both free radical scavenger as an inducer of the body's own endogenous defence mechanisms by regulating tyrosinase activity and stimulating melanin production. Malonyldialdehyde formation (TBARS) was delayed when RA was used. The protection factor was 3.24 times vs AA. TEAC value for RA was 1.6 times vs AA. The radioprotective-antimutagenic effects of RA were measure using the micronucleus test. The level of micronucleous for treatments before irradiation was: RA [14]

ORAC-fluorescein assay to determine the oxygen radical absorbance capacity of resveratrol complexed in cyclodextrins.

The effect of the complexation of resveratrol with hydroxypropyl-beta-cyclodextrins (HP-beta-CDs) on the antioxidant capacity of the polyphenol is studied for the first time by means of the oxygen radical absorbance capacity (ORAC) method, using fluorescein (FL) as the fluorescent probe. The method is validated through its linearity, precision, and accuracy for measuring the ORAC of resveratrol in the absence or presence of cyclodextrins (CDs). The complexation of resveratrol in CDs increased the net area under the FL decay curve (net AUC) of resveratrol up to its saturation level, at which the polyphenol showed almost double the antioxidant activity it shows in the absence of CDs. The complexation constant ( K c) between resveratrol and HP-beta-CDs was calculated by linear regression of the phase solubility diagram ( K c = 18048 M (-1)). The antioxidant activity of resveratrol was dependent on the complexed resveratrol because CDs acts as a controlled dosage reservoir that protects resveratrol against rapid oxidation by free radicals. In this way, its antioxidant activity is prolonged and only reaches its maximum when all the resveratrol is complexed.

Development of a simple extraction procedure for chlorpyrifos determination in food samples by immunoassay.

The suitability of immunoassay methodology for rapid and accurate determination of chlorpyrifos in vegetables was tested. The optimised ELISA detection limit was 0.32ng/ml, with a working range from 0.69 to 6.21ng/ml and an immunoassay test-mid point (IC(50)) of 2.08ng/ml. A rapid sample preparation procedure considering different parameters such as the amount of sample, volume of extractant, extraction time and dilution factor was optimised. The developed direct extraction (DE) and multiresidue (ME) standard procedures were performed in different fortified fresh and processed vegetable samples (tomato, bonnet pepper, bean, pea, asparagus, broccoli, watermelon, melon, lettuce, cucumber, celery and red pepper). Recoveries were in all cases in the whole range 85.2-108.9% for both DE and ME extracts. Also, the comparison of the results obtained by both immunochemical and chromatographic methods for spiked fruits and vegetables were good with a correlation coefficient (r) of 0.97.

Determination of atrazine and carbaryl pesticide residues in vegetable samples using a multianalyte dipstick immunoassay format.

A dipstick assay for the simultaneous determination of atrazine and carbaryl in vegetable samples was developed. The analytical method involved a fast extraction procedure followed by a multi-strip membrane test. The assay took 10 min, with a detection limit (naked eye) of 10 and 200 micro g l(-1) for atrazine and carbaryl, respectively. The cross-reactivities to related compounds tested were negligible except for propazine. Quantification of the pesticides was carried out by measuring the dot colour with a spectrophotometer. IC(50) values (inhibition constant at 50% of the maximum binding) of 2.04 microg l(-1) for atrazine and 92.8 microg l(-1) for carbaryl were achieved by this approach. Vegetable samples were extracted with MeOH. The proposed methodology was used to analyse atrazine and carbaryl and check for compliance with European Union maximum residue levels for vegetables. Recoveries (75-105%) were in agreement with those obtained by GC/MS or HPLC. Standard curves using 25% methanol/75% TBS were used for food sample assays using a multi-analyte dipstick. IC(50) values were 9.2 microg kg(-1) for atrazine and 179.2 microg kg(-1) for cabaryl.

Current trends in immunoassay-based kits for pesticide analysis.

Detection of pesticides and their metabolites in food and environmental samples in real time is the goal of many industries. Immunoassay technology has several attributes that make it a useful tool for screening purposes (e.g., selectivity, sensitivity, portability, and rapid turnaround time). Approximately 90% of the developed immunoassays for the pesticide residue analysis use the ELISA technique. Commercial kits are tailored to target different analytes, thus eliminating in some cases the need for clean-up steps. The manageability of the immunoassay test kit, together with its accuracy and speed of analysis, allows the rapid determination in situ of many samples simultaneously. This article gives an overview on the applications of the immunokits for pesticide analysis in drinking water and foods, as well as examples of different immunoassay formats commonly used. Special attention is given to sample extraction and clean-up procedures. Application to the determination of common pesticides and their detection limit are summarized. Immunoassay kits offer many practical advantages, and the acceptance of these methods depends on several factors, including the demonstration of quality and validity compared with reference methods. Although the advantages of the technique and their applications to food industry quality control are scarcely referred to in the literature.