RESUMEN

BACKGROUND: The Nociception Level Index has shown benefits in estimating the nociception/antinociception balance in adults, but there is limited evidence in the pediatric population. Evaluating the index performance in children might provide valuable insights to guide opioid administration. AIMS: To evaluate the Nociception Level Index ability to identify a standardized nociceptive stimulus and the analgesic effect of a fentanyl bolus. Additionally, to characterize the pharmacokinetic/pharmacodynamic relationship of fentanyl with the Nociception Level Index response during sevoflurane anesthesia. METHODS: Nineteen children, 5.3 (4.1-6.7) years, scheduled for lower abdominal or urological surgery, were studied. After sevoflurane anesthesia and caudal block, a tetanic stimulus (50 Hz, 60 mA, 5 s) was performed in the forearm. Following the administration of fentanyl 2 µg/kg intravenous bolus, three similar consecutive tetanic stimuli were performed at 5-, 15-, and 30-min post-fentanyl administration. Changes in the Nociception Level Index, heart rate, mean arterial pressure, and bispectral index were compared in response to the tetanic stimuli. Fentanyl plasma concentrations and the Nociception Level Index data were used to elaborate a pharmacokinetic/pharmacodynamic model using a sequential modeling approach in NONMEM®. RESULTS: After the first tetanic stimulus, both the Nociception Level Index and the heart rate increased compared to baseline (8 ± 7 vs. 19 ± 10; mean difference (CI95) -12(-18--6) and 100 ± 10 vs. 102 ± 10; -2(-4--0.1)) and decrease following fentanyl administration (19 ± 10 vs. 8 ± 8; 12 (5-18) and 102 ± 10 vs. 91 ± 11; 11 (7-16)). In subsequent tetanic stimuli, heart rate remained unchanged, while the Nociception Level Index progressively increased within 15 min to values similar to those before fentanyl. An allometric weight-scaled, 3-compartment model best characterized the pharmacokinetic profile of fentanyl. The pharmacokinetic/pharmacodynamic modeling analysis revealed hysteresis between fentanyl plasma concentrations and the Nociception Level Index response, characterized by plasma effect-site equilibration half-time of 1.69 (0.4-2.9) min. The estimated fentanyl C50 was 1.93 (0.73-4.2) ng/mL. CONCLUSION: The Nociception Level Index showed superior capability compared to traditional hemodynamic variables in discriminating different nociception-antinociception levels during varying fentanyl concentrations in children under sevoflurane anesthesia.

Asunto(s)

Analgésicos Opioides , Anestesia General , Anestésicos por Inhalación , Fentanilo , Nocicepción , Sevoflurano , Humanos , Fentanilo/farmacocinética , Fentanilo/administración & dosificación , Fentanilo/farmacología , Sevoflurano/farmacología , Sevoflurano/farmacocinética , Sevoflurano/administración & dosificación , Masculino , Femenino , Niño , Nocicepción/efectos de los fármacos , Preescolar , Anestésicos por Inhalación/farmacocinética , Anestésicos por Inhalación/farmacología , Anestésicos por Inhalación/administración & dosificación , Anestesia General/métodos , Analgésicos Opioides/farmacocinética , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Anestésicos Intravenosos/farmacocinética , Anestésicos Intravenosos/farmacología , Anestésicos Intravenosos/administración & dosificación , Éteres Metílicos/farmacocinética , Éteres Metílicos/farmacología , Éteres Metílicos/administración & dosificación

RESUMEN

Sticherus squamulosus, Hymenophyllum dentatum, Blechnum microphyllum, Polypodium Feuillei, Blechnum chilense, Lophosoria quadripinnata, and Lissopimpla excelsa are native fern species found in southern Chile and are often used in traditional medicine. However, their bioactive properties have not been confirmed. In this study, ethanolic extracts of ferns exhibited significant antibacterial capacity against human pathogens. H. dentatum and S. squamulosus were selected for further analysis owing to their antimicrobial and antioxidant capacities. The entire H. dentatum extract exhibited fungistatic and fungicidal capacity on Botrytis cinerea and Penicillium digitatum, with minimum inhibitory concentration values of 1.56 mg/mL and 6.25 mg/mL and minimum fungicidal concentration values of 6.25 mg/mL and 12.5 mg/mL, respectively. The S. squamulosus extract presented the highest rutin content (222.5 µg/g fern). In addition, the ethanolic extract of H. dentatum inhibited 91% of DPPH radicals. Therefore, both types of ferns can be used in the food industry.

RESUMEN

Intra-amniotic infection with Candida species is an uncommon but severe condition with high fetal morbimortality and no established clinical guidelines for its management. We report a Candida albicans intra-amniotic infection diagnosed in a 25-week pregnant woman, successfully treated with high-dose liposomal amphotericin B. Pregnancy was prolonged until 30 weeks, and despite persistently positive Candida cultures in amniotic fluid, a healthy newborn was delivered without evidence of systemic infection. Amphotericin concentration was determined at birth, revealing levels over 30 times higher in mother's and cord blood than in the amniotic fluid, probably explaining the clinical protection despite failure in obtaining fungal clearance.

RESUMEN

The microencapsulation of bioactive extracts of Chilean papaya waste, including both seeds and skin, was investigated. Papaya waste extract microcapsules utilizing maltodextrin at 10% (MD10), 20% (MD20), and 30% (MD30) (w/v) as the wall material through the freeze-drying process were obtained, and subsequently their physicochemical, antioxidant, and antimicrobial properties were evaluated. The TPC efficiency and yield values achieved were more than 60% for the microencapsulated seed and skin extracts, respectively. The best results for phenolic and antioxidant compounds were found in the microencapsulated seed extract with MD20, with a value of 44.20 ± 3.32 EAG/g DW for total phenols and an antioxidant capacity of 12.0 ± 0.32 mol ET/g DW for the DPPH and 236.3 ± 4.1 mol ET/g DW for the FRAP assay. In addition, the seed and skin samples reduced ROS generation in H2O2-treated Hek293 cells. In terms of antimicrobial activity, values ranging from 7 to 15 mm of inhibitory halos were found, with the maximum value corresponding to the inhibition of S. aureus, for both microencapsulated extracts. Therefore, the successful microencapsulation of the waste bioactive extracts (seed and skin) with the demonstrated antimicrobial and antioxidant properties highlight the bioactivity from Chilean papaya waste resources.

RESUMEN

Pregnancies are a critical window period for environmental influences over the mother and the offspring. There is a growing body of evidence associating indoor and outdoor air pollution exposure to adverse pregnancy outcomes such as preterm birth and hypertensive disorders of pregnancy. Particulate matter (PM) could trigger oxi-inflammation and could also reach the placenta leading to placental damage with fetal consequences. The combination of strategies such as risk assessment, advise about risks of environmental exposures to pregnant women, together with nutritional strategies and digital solutions to monitor air quality can be effective in mitigating the effects of air pollution during pregnancy.

Asunto(s)

Contaminación del Aire Interior , Contaminación del Aire , Nacimiento Prematuro , Recién Nacido , Embarazo , Femenino , Humanos , Placenta , Exposición a Riesgos Ambientales

RESUMEN

Honeybee pollen (HBP) is a mixture of floral pollen collected by honeybees near the hive. It is characterized by a composition rich in phenolic compounds, carotenoids and vitamins that act as free radicals scavengers, conferring antioxidant and antibacterial capacity to the matrix. These bioactive properties are related to the botanical origin of the honeybee pollen. Honeybee pollen samples were collected from different geographical locations in central Chile, and their total carotenoid content, polyphenols profile by HPLC/MS/MS, DPPH radical scavenging capacity, and antimicrobial capacity against S. pyogenes, E. coli, S. aureus, and P. auriginosa strains were evaluated. Our results showed a good carotenoids content and polyphenols composition, while antioxidant capacity presented values between 0-95 % for the scavenging effect related to the botanical origin of the samples. Inhibition diameter for the different strains presented less variability among the samples, Furthermore, binary mixtures representing the two most abundant species in each HBP were prepared to assess the synergy effect of the floral pollen (FP) present in the samples. Data shows an antagonist effect was observed when assessing the carotenoid content, and a synergy effect often presents for antimicrobial and antioxidant capacity for bee pollen samples. The bioactive capacities of the honeybee pollen and their synergy effect could apply to develop new functional ingredients for the food industry.

Asunto(s)

Antiinfecciosos , Antioxidantes , Abejas , Polen , Animales , Antiinfecciosos/farmacología , Antioxidantes/farmacología , Antioxidantes/análisis , Abejas/química , Abejas/metabolismo , Carotenoides/farmacología , Carotenoides/análisis , Escherichia coli , Polen/química , Polifenoles/farmacología , Polifenoles/análisis , Staphylococcus aureus , Espectrometría de Masas en Tándem

RESUMEN

The extraction of bioactive compounds from fruits, such as lemon, has gained relevance because these compounds have beneficial properties for health, such as antioxidant and anticancer properties; however, the extraction method can significantly affect these properties. High hydrostatic pressure and ultrasound, as emerging extraction methods, constitute an alternative to conventional extraction, improving extractability and obtaining extracts rich in bioactive compounds. Therefore, lemon extracts (LEs) were obtained by conventional (orbital shaking), ultrasound-assisted, and high-hydrostatic-pressure extraction. Extracts were then microencapsulated with maltodextrin at 10% (M10), 20% (M20), and 30% (M30). The impact of microencapsulation on LEs physicochemical properties, phenolics (TPC), flavonoids (TFC) and relative bio-accessibility (RB) was evaluated. M30 promoted a higher microencapsulation efficiency for TPC and TFC, and a longer time required for microcapsules to dissolve in water, as moisture content, water activity and hygroscopicity decreased. The RBs of TPC and TFC were higher in microcapsules with M30, and lower when conventional extraction was used. The data suggest that microencapsulated LE is promising as it protects the bioactivity of phenolic compounds. In addition, this freeze-dried product can be utilized as a functional ingredient for food or supplement formulations.

Asunto(s)

Fenoles , Extractos Vegetales , Antioxidantes/química , Antioxidantes/farmacología , Cápsulas/química , Fenoles/química , Extractos Vegetales/química , Agua

RESUMEN

Alzheimer's disease (AD) is a degenerative neurological disease characterized by gradual loss of cognitive skills and memory. The exact pathogenesis involved still remains unrevealed, but several studies indicate the involvement of an array of different enzymes, underlining the multifactorial character of the disease. Inhibition of these enzymes is therefore a powerful approach in the development of AD treatments, with promising candidates, including acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and monoamine oxidase. Interestingly, AChE is the target of a major pesticide family (organophosphates), with several reports indicating an intersection between the pesticide's activity and AD. In this study, various TADDOL derivatives were synthesized and their in vitro activities as AChE/BuChE inhibitors as well as their antioxidant activities were studied. Molecular modeling studies revealed the capability of TADDOL derivatives to bind to AChE and induce inhibition, especially compounds 2b and 3c furnishing IC50 values of 36.78 ± 8.97 and 59.23 ± 5.31 µM, respectively. Experimental biological activities and molecular modeling studies clearly demonstrate that TADDOL derivatives with specific stereochemistry have an interesting potential for the design of potent AChE inhibitors. The encouraging results for compounds 2b and 3c indicate them as promising scaffolds for selective and potent AChE inhibitors.

Asunto(s)

Enfermedad de Alzheimer , Plaguicidas , Humanos , Butirilcolinesterasa/metabolismo , Acetilcolinesterasa/metabolismo , Simulación del Acoplamiento Molecular , Relación Estructura-Actividad , Inhibidores de la Colinesterasa/farmacología , Inhibidores de la Colinesterasa/química , Plaguicidas/farmacología

RESUMEN

Plant biochemistry studies have increased in recent years due to their potential to improve human health. Argylia radiata is an extremophile plant with an interesting polyphenolic profile. However, its biomass is scarce and occasionally available. Argylia in vitro biomass was obtained from tissue culture and compared with in vivo roots regarding its polyphenolic and flavonoid content. Different solvents were used to prepare extracts from the in vitro tissue of callus and aerial plant organs and in vivo roots. UPLC-MS/MS was used to assess the chemical composition of each extract. ORAC-FL and scavenging of free radicals (DPPH and OH) methods were used to determine the antioxidant capacity of extracts. Furthermore, the biological activity of the extracts was established using the cellular antioxidant activity method. The vitroplants were a good source of polyphenols (25-68 mg GAE/100 g tissue FW), and methanol was the most efficient solvent. Eight polyphenolic compounds were identified, and their antioxidant properties were investigated by different chemical methods with EPR demonstrating its specific scavenging activity against free radicals. All extracts showed cellular dose-dependent antioxidant activity. The methanolic extract of vitroplants showed the highest cellular antioxidant activity (44.6% and 51%) at 1 and 10 µg/mL of extract, respectively. Vitroplants of A. radiata are proposed as a biotechnological product as a source of antioxidant compounds with multiple applications.

Asunto(s)

Antioxidantes/farmacología , Begoniaceae/química , Depuradores de Radicales Libres/farmacología , Raíces de Plantas/química , Polifenoles/análisis , Polifenoles/farmacología , Solventes/química

RESUMEN

Myrtaceae fruits (Myrceugenia obtusa, Luma apiculata, and Luma chequen) were used as food and medicine by Chilean indigenous people. This study aimed to evaluate the bioactive properties of these berry-type fruits. The antioxidant capacity determined by the FRAP assay varied between 10.4 and 646.9 mmol Fe+2/g, while the antibacterial activity against Staphylococcus aureus and Salmonella typhi was 0 - 33 mm and 0 - 7.33 mm, respectively. All the extracts were rich in polyphenols and showed low cytotoxicity. Overall, M. obtusa presented dissimilar results compared to those of L. apiculata and L. chequen, encouraging the use of these native fruits as food, nutraceutical, or pharmacological ingredients.

Asunto(s)

Myrtaceae , Antioxidantes/farmacología , Chile , Frutas , Alimentos Funcionales , Humanos , Extractos Vegetales/farmacología , Polifenoles/farmacología

RESUMEN

Eucryphia cordifolia is a native and dominant species from the Temperate Forest in the southern region of Chile. It is a crucial melliferous species producing unifloral honey with outstanding antibacterial properties with great commercial value at international markets. A phytochemical screening was developed by colorimetric and gravimetric methods. Antioxidant activities were assessed by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric ion reducing antioxidant power (FRAP) method. The minimum bactericidal concentration (MBC) was the method used to determine the antibacterial activity. The results revealed the highest antioxidant activity for the methanolic extracts of branches (IC50 35.7 µg/mL for DPPH, IC50 11.0 µg/mL for ABTS, and 4.6 mM FeSO4·7H2O/g in FRAP), attributed to its high content of total phenols (332.8 mg GAE/g). The quantification of the MBC led to values in the range of 0.78-12.5 mg/mL for S. aureus and S. pyogenes, and 6.25-50 mg/mL for E. coli and P. aeruginosa, respectively. The presented work provides valuable first in vitro evidence regarding the potential application of E. cordifolia extracts as antioxidants and antibacterial agents in the nutraceutical and phytopharmaceutical industry.

Asunto(s)

Antioxidantes , Staphylococcus aureus , Antibacterianos/farmacología , Antioxidantes/farmacología , Escherichia coli , Pruebas de Sensibilidad Microbiana , Fitoquímicos/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología

RESUMEN

Honey is a natural product with a sweet flavor. Honey is made by the honeybee (Apis mellifera L.) from the nectar of flowers or other plant secretions that are collected near the hive. These products are mixed with bee saliva and stored. Several studies have demonstrated that honey exhibits antioxidant, antimicrobial, nematicidal, antifungal, anticancer, and anti-inflammatory activities. These properties are influenced by the plants from which the secretions are harvested, from the naturally occurring compounds present in the nectar. Studies of the properties and applications of honey have distinguished honey from other natural products due to the presence of certain compounds and due its bioactive properties. The focus of this review is to discuss the identified and isolated compounds from monofloral honey produced by A. mellifera, with specific emphasis on antioxidant and antimicrobial properties of honey and its therapeutic health benefits.

Asunto(s)

Antibacterianos/química , Antibacterianos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Apiterapia , Miel/análisis , Miel/clasificación , Animales , Abejas/clasificación , Geografía

RESUMEN

The Mayten tree (Maytenus boaria Mol.), a native plant of Chile that grows under environmentally limiting conditions, was historically harvested to extract an edible oil, and may represent an opportunity to expand current vegetable oil production. Seeds were collected from Mayten trees in north-central Chile, and seed oil was extracted by solvent extraction. The seed oil showed a reddish coloration, with quality parameters similar to those of other vegetable oils. The fatty acid composition revealed high levels of monounsaturated and polyunsaturated fatty acids. Oleic and linoleic acids, which are relevant to the human diet, were well represented in the extracted Mayten tree seed oil. The oil displayed an antioxidant capacity due to the high contents of antioxidant compounds (polyphenols and carotenoids) and may have potential health benefits for diseases associated with oxidative stress.

RESUMEN

Extracts rich in bioactive compounds added to edible films have allowed the development of active packaging that increases the shelf life of food. However, it is necessary to search for solvents that are nontoxic and not harmful to the environment, with natural deep eutectic solvents (NADES) being an attractive and easily synthesized alternative. This research aimed to design NADES by lyophilization to be used in the extraction of anthocyanins from the Chilean Luma chequen (Molina) A. Gray berry, and subsequently adding them to the matrix of edible ƙ-carrageenan films. For this purpose, ultrasound-assisted extraction (UAE) was used and the anthocyanin content was evaluated with the pH differential method. The antioxidant capacity of extracts was determined by DPPH assay and the antibacterial capacity by diffusion agar tests. The results obtained indicate that the designed NADES are efficient at extracting anthocyanins, reaching concentrations between 81.1 and 327.6 mg eq cyanidin 3-glucoside/100 g dw of L. chequen (Molina) A. Gray. The extracts reached inhibition diameters between 5 and 34 mm against Escherichia coli, Staphylococcus aureus, and Salmonella typhi strains. Once the extracts were incorporated into ƙ-carrageenan films, active edible films with antioxidant and antibacterial capacities were obtained.

Asunto(s)

Antocianinas/aislamiento & purificación , Antioxidantes/química , Películas Comestibles , Embalaje de Alimentos , Antocianinas/química , Antioxidantes/aislamiento & purificación , Antioxidantes/farmacología , Carragenina/química , Carragenina/farmacología , Frutas/química , Humanos , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Solventes/química , Ultrasonido

RESUMEN

The polyphenolic distribution on different organs of Argylia radiata, an extremophile plant from the Atacama "Flowering Desert", is presented herein for the first time. For this purpose, the total phenolic content and antioxidant capacity of ethanolic extracts from leaves, tuberous root and flowers of different colors were evaluated. Orange and red flowers showed the highest polyphenolic and flavonoid content. The maximum anthocyanin concentration was found in red flowers and the antioxidant activity (FRAP) of extracts changed according to the organ. The UPLC-MS/MS analysis of the extracts allowed to identify 10 new polyphenols belonging to different families. Rutin was identified as the most abundant polyphenol in all plant organs, followed by quercetin and coumaric acid. Their role in plant response to abiotic and biotic stress, as well as their potential biotechnological application are discussed.

Asunto(s)

Antioxidantes/farmacología , Bignoniaceae/química , Extractos Vegetales/farmacología , Polifenoles , Chile , Cromatografía Liquida , Clima Desértico , Extremófilos , Flavonoides/análisis , Flavonoides/farmacología , Hojas de la Planta/química , Polifenoles/análisis , Polifenoles/farmacología , Espectrometría de Masas en Tándem

RESUMEN

Nalca is an edible rhubarb-type plant from the southern of Chile; with studies focussing on petiole chemical and biological properties. This work evaluated for the first time the antibacterial capacities of three organs of nalca against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Petiole (P), root (R) and flower (F) ethanolic extracts at three different concentrations (25, 50, 100 mg/mL) were evaluated by means of agar diffusion assay and MIC. The result showed that antibacterial activities are bacteria and concentration dependent, with root having the highest antimicrobial activity of the organs plant studied. Compared to commercial antibiotics, nalca extracts show promising control over Ps. aeruginosa. The main polyphenolics of the extracts were identified by UPLC-MS/MS, observing for the first time caffeic, coumaric and gallic acids presence in all samples, with quercetin and rutin determined in petiole and flower extracts only. Our results contribute to better understanding of nalca attributes as potential source of antibacterial compounds to be used in nutraceutical, cosmetic and food industry.

Asunto(s)

Extractos Vegetales , Espectrometría de Masas en Tándem , Antibacterianos/farmacología , Cromatografía Liquida , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología

RESUMEN

The present study investigated the antioxidant potential and the ability to inhibit lipid and protein oxidation in bovine meat of four native Chilean species: canelo (Drimys winteri), nalca (Gunnera tinctoria), tiaca (Caldcluvia paniculata), and ulmo (Eucryphia cordifolia). Phenolic acids (gallic, chlorogenic, caffeic, and coumaric) and flavonoids (catechin, epicatechin, and rutin) were identified and quantified by HPLC-MS/MS. Drimys winteri extract exhibited the highest antioxidant capacity evaluated by oxygen radical absorption capacity-red pyrogallol method (ORAC-PGR) and ferric ion reducing antioxidant power (FRAP) assays. All extracts decreased lipid oxidation induced by 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH) derived peroxyl radicals by anywhere between 30% and 50% the. In addition, canelo and nalca extracts decreased spontaneous oxidation by around 57% and 37% in relation to the control group, being even more efficient than butylated hydroxyanisole (BHT) a synthetic antioxidant. Protein oxidation in the myofibrillar proteins was evaluated by the formation of protein carbonyls and loss of protein thiols. The canelo, ulmo, and nalca extracts decreased the formation of carbonyls by around 30%. Plant extracts and BHT did not show an antioxidant effect on protein thiol loss. However, tiaca and ulmo extracts exerted a pro-oxidant effect, favoring the oxidation of sulfhydryl groups. The oxidizing system induced structural changes in myofibrillar protein (SDS-PAGE). A protective effect on protein structure from the canelo extract can be observed during the incubation when compared to samples incubated with AAPH.

Asunto(s)

Antioxidantes/farmacología , Peroxidación de Lípido/efectos de los fármacos , Magnoliopsida/química , Proteínas Musculares/química , Animales , Antioxidantes/química , Bovinos , Flavonoides/química , Flavonoides/farmacología , Hidroxibenzoatos/química , Hidroxibenzoatos/farmacología , Componentes Aéreos de las Plantas/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/química

RESUMEN

ABSTRACT Neonicotinoids are a relatively new generation of insecticides that have been used for control of pests such as aphids, leafhoppers and whiteflies. This paper presents for the first time a determination of residues of four neonicotinoid insecticides (acetamiprid, thiamethoxam, thiacloprid and imidacloprid) in Chilean honey using QuEChERS extraction and UHPLC-MS/MS analysis. The limits of detection and quantification found for all analytes ranging from 0.34 to 1.43 μg kg-1 and from 0.30 to 4.76 μg kg-1, respectively. The extraction using QuEChERS method provided recoveries over 79% and the precision showed coefficient of variation lower than 20%. These data are in agreement with the international criteria that recommend general recovery limits of 70 - 120%. Of the 16 samples analyzed, in three honey samples neonicotinoids pesticides were detected. These three samples were collected from the same geographical area (Rengo). Fruit and grain production characterize the province of Rengo. The analysis of the botanical origin of these honeys showed the absence of pollen grains of crops and the majority presence of pollen grains of weeds such as Medicago sativa, Galega officinalis and Brassica rapa, which could be associated with crops. Although the residue levels found were low, the results also confirm the actual occurrence of a transfer of neonicotinoid insecticides from exposed honeybees into honey.

---

RESUMO Os neonicotinóides são uma geração relativamente nova de inseticidas que tem sido utilizado para o controle de pragas, como pulgões, cigarrinhas e moscas brancas. Este artigo apresenta pela primeira vez a determinação de resíduos de quatro inseticidas neonicotinóides (acetamiprida, tiametoxam, tiaclopride e imidaclopride) em méis chilenos empregando para extração o método QuEChERS seguido de UHPLC-MS/MS. Foram encontrados limites de detecção e quantificação aceitáveis para todos os analitos variando de 0,34 a 1,43 μg kg-1 e de 0,30 a 4,76 μg kg-1, respectivamente. A extração usando o método QuEChERS proporcionou uma recuperação maior que 79% e a precisão do método não excedeu um coeficiente de variação de 20%. Esses dados estão de acordo com os critérios internacionais que recomendam limites gerais de recuperação de 70 - 120%. Das 16 amostras de mel analisadas foram detectados pesticidas neonicotinoides em três delas. Essas três amostras foram coletadas na mesma área geográfica (Rengo), a qual se caracteriza pela produção de grãos e frutas. A análise da origem botânica desses méis mostrou a ausência de grãos de pólen de espécies cultivadas nesta zona, porém mostrou uma presença majoritária de grãos de pólen de ervas daninhas, como Medicago sativa, Galega officinalis e Brassica rapa, as quais podem estar associadas a estes cultivos. Embora os níveis de resíduos neonicotinoides encontrados neste estudo são baixos, os resultados confirmam a ocorrência atual de uma transferência destes inseticidas ao mel das de abelhas expostas.

RESUMEN

Propolis has been proposed as a polyphenolic-rich natural product potentially able to be used for human consumption or even for medicinal proposes. To guarantee a minimum phenolic and flavonoid content and as consequence of their related-biological activities, international requirements of propolis quality are commonly applied. In this work we assessed phenolic and flavonoid contents of propolis; the antioxidant capacity (toward peroxyl radicals and hypochlorous acid); the ability to generate nitric oxide (NO); and, finally the antimicrobial activity of 6 propolis samples from the VI region of Chile. Our results show that the total phenolic and flavonoid content of propolis samples are not always in agreement with their polyphenolic-associated in vitro activities. For example, P03 and P06 samples showed the lowest (25 ± 4 GAE/g propolis) and the highest (105 ± 3 GAE/g propolis) total phenolic content, respectively. This was in agreement with flavonoid content and their Oxygen Radical Absorbance Capacity (ORAC) activity. However, this dependence was not observed toward HOCl, NO release and antimicrobial activity. Based on our results, we consider that, in order to guarantee the antioxidant or antimicrobial in vitro effects, the international regulations of propolis quality should contemplate the convenience of incorporating other simple analytical test such as ORAC or antimicrobial tests.

Asunto(s)

Antiinfecciosos/farmacología , Antioxidantes/farmacología , Flavonoides/análisis , Fenoles/análisis , Extractos Vegetales/farmacología , Própolis/química , Antiinfecciosos/análisis , Antioxidantes/análisis , Chile , Humanos , Cooperación Internacional , Óxido Nítrico , Extractos Vegetales/análisis , Polifenoles/análisis , Polifenoles/farmacología , Própolis/normas , Especies Reactivas de Oxígeno

RESUMEN

The rotating disk sorptive extraction (RDSE) technique was applied to the determination of pesticides in aqueous samples. Pesticides of different polarities were considered in this study: chlorpyrifos, diazinon, fenvalarate, cyhalothrin, cypermethrin, lindane and malathion. The sorptive/desorptive behavior of the pesticides was studied using a rotating disk containing a polydimethylsiloxane (PDMS) phase on one of its surfaces. The analyte polarity was a significant factor in the extraction time; shorter extraction times were required for the more apolar pesticides. The optimum variables for the extraction of all analytes were: extraction time of 3h, sample volume of 25 mL, rotational velocity of the disk 1250 rpm, desorption time of 30 min using methanol. For pesticides with values of Log K(ow)>4, the extraction time can be reduced to 30 min for a quantitative extraction. Under these conditions, recoveries between 76% and 101% were obtained for the target pesticides, and the repeatability of the methodology, expressed as relative standard deviation, was determined to be between 10% and 20%. Additionally, the limits of detection of the analytes were lower than 3.1 µg L(-1). The extraction method developed using the RDSE was compared to a stir bar sorptive extraction (SBSE) under the same conditions. It can be observed that the extraction using the rotating disk offers higher recoveries because of its higher PDMS volume and its higher surface area to volume ratio that allows for improved mass transfer.