Persistence and metabolism of the diamide insecticide cyantraniliprole in tomato plants.

Plant uptake and metabolism of pesticides are complex and dynamic processes, which contribute to the overall toxicity of the pesticides. We investigated the metabolic fate of cyantraniliprole, a new diamide class of insecticide, during various growth stages of tomato. Cyantraniliprole was the major residue in leaves, flowers, and fruits, with the relative metabolite-to-parent ratios maintained at < 10% up to 28 days after treatment (DAT). Mature leaves contained consistently higher residues of cyantraniliprole than young leaves throughout the study. Flowers contained the highest cyantraniliprole residues up to 21 DAT, then gradually decreased. Immature green fruits had the highest cyantraniliprole residues (5.3 ± 0.7 ng/g; 42 DAT), and decreased toward red ripening stages (1.4 ± 0.2 ng/g; 84 DAT). Metabolism of cyantraniliprole primarily occurred in the foliage, where 21 metabolites were tentatively identified. Flowers and fruits contained 14 and four of these metabolites, respectively. Major transformation pathways were characterized by ring closure, followed by N-demethylation, and glycosylation. Additionally, plant metabolism of cyantraniliprole was also associated with several minor phase-I, phase-II, and breakdown metabolites. The occurrence of these metabolites in plants varied as a function of tissue types and their developmental stages. Our study highlights a tissue-specific biotransformation and accumulation of metabolites of cyantraniliprole in tomato.

Quantification of field-incurred residues of cyantraniliprole and IN-J9Z38 in cabbage/soil using QuEChERS/HPLC-PDA and dietary risk assessment.

Cyantraniliprole is an anthranilic diamide insecticide used for the effective management of diamondback moth in cabbage. Dietary risk assessment of pesticides in food is a major concern now. This study developed a QuEChERS/HPLC-PDA-based highly efficient and reliable method, registering 89.80-100.11% recoveries of cyantraniliprole and its metabolite IN-J9Z38 from cabbage and soil with a relative standard deviation of 0.43-5.77%. Field experiment was conducted to study the residue dissipation of cyantraniliprole in cabbage and soil. Two foliar treatments of 10.26% formulation (Benevia) at 60 (T1 ) and 120 (T2 ) gram active ingredient/hectare were applied. The dissipation half-lives of cyantraniliprole in cabbage and soil were determined to be 3.5-4.2 and 3.8-5.3 days at T1 and 3.9-4.8 and 4.1-4.7 days at T2 , respectively. The maximum concentrations of IN-J9Z38 at T1 and T2 were 0.819 and 1.061 mg/kg, respectively, on the fifth day. A risk quotient value of <1 indicates no dietary risk to the consumers. The residues in the harvested cabbage were below the tolerance level of 2.0 mg/kg established by the regulatory body in India.

Dissipation and transformation of the diamide insecticide cyantraniliprole in ornamental snapdragon (Antirrhinum majus).

Dissipation and transformation of cyantraniliprole, a new diamide class of insecticides, were investigated under greenhouse conditions, using snapdragon (Antirrhinum majus) as the model plant. Dissipation of cyantraniliprole in treated leaves was found to be dependent upon application methods (foliar spray versus soil drench) and doses (high versus low dose), with the parent insecticide being the major residue at various sampling points. A high-dose foliar application resulted in pesticide residue of 6.7-23.8 µg/g foliar fresh weight over 8 weeks of treatments, while in soil drench treatment the residue varied from 0.8 to 1.4 µg/g. However, the residue contents were similar between the two application methods at a low application dose. The transformation pathways of cyantraniliprole were primarily intramolecular rearrangements, with IN-J9Z38 being the major metabolite across treatments. Several other metabolites were also identified, some of which were unique to the application methods. Out of total 26 metabolites tentatively identified in this study, 10 metabolites were unique to foliar application, while six metabolites were unique to soil drench. In addition to plant-mediated biotransformation, photodegradation of the parent compound was identified as a potential mechanism in foliar application.

Development and validation of a simultaneous analytical method for non-steroidal therapeutic compounds in cosmetics using liquid chromatography-tandem mass spectrometry.

Atopic dermatitis is a typical chronic inflammatory skin disease that affects all age groups and requires basic skin care for treatment. Anti-inflammatory and antiallergy steroids are the most frequently used treatments but they are limited due to their side effects caused by a weakening of the immune system. Many consumers focus on performance as a criterion for selecting cosmetics. However, steroids have been illegally used to improve the performance of cosmetics, and consumers have been adversely affected by the corresponding side effects. In this paper, we propose a simple and rapid method using liquid chromatography-tandem mass spectrometry to simultaneously analyze ten non-permitted atopic therapeutic compounds in cosmetic products: chlorpheniramine maleate, ketotifen fumarate, doxepin hydrochloride, azelastine hydrochloride, bufexamac, clotrimazole, tranilast, fusidic acid, tacrolimus, and pimecrolimus. Additionally, the major characteristic fragment ions for tacrolimus, pimecrolimus, and clotrimazole were identified by time-of-flight mass spectrometry. The specificity, linearity, limit of detection, limit of quantification, recovery, precision, accuracy, and stability of the proposed method were validated. The limit of detection and quantification were in the ranges of 5.05-203.30 pg/mL and 15.15-609.90 pg/mL, respectively. The proposed analysis method could help improve the safety management of cosmetics.

Detection of chlorantraniliprole residues in tomato using field-deployable MIP photonic sensors.

A photonic sensor based on inversed opal molecular imprinted polymer (MIP) film to detect the presence of chlorantraniliprole (CHL) residue in tomatoes was developed. Acrylic acid was polymerized in the presence of CHL inside the structure of a colloidal crystal, followed by etching of the colloids and CHL elution. Colloidal crystals and MIP films were characterized by scanning electron microscopy and FT-IR, confirming the inner structure and chemical structure of the material. MIP films supported on polymethylmethacrylate (PMMA) slides were incubated in aqueous solutions of the pesticide and in blended tomato samples. The MIP sensor displayed shifts of the peak wavelength of the reflection spectra in the visible range when incubated in CHL concentrations between 0.5 and 10 µg L-1, while almost no peak displacement was observed for non-imprinted (NIP) films. Whole tomatoes were blended into a liquid and spiked with CHL; the sensor was able to detect CHL residues down to 0.5 µg kg-1, significantly below the tolerance level established by the US Environmental Protection Agency of 1.4 mg kg-1. Stable values were reached after about 30-min incubation in test samples. Control samples (unspiked processed tomatoes) produced peak shifts both in MIP and NIP films; however, this matrix effect did not affect the detection of CHL in the spiked samples. These promising results support the application of photonic MIP sensors as an economical and field-deployable screening tool for the detection of CHL in crops.

Development of a nanobody-based ELISA for the detection of the insecticides cyantraniliprole and chlorantraniliprole in soil and the vegetable bok choy.

Cyantraniliprole and chlorantraniliprole are anthranilic diamide insecticides acting on ryanodine receptors. In this study, two camel-derived nanobodies (Nbs, named C1 and C2) recognizing cyantraniliprole as well as chlorantraniliprole were generated. C1-based enzyme-linked immunosorbent assays (ELISAs) for the detection of the two insecticides were developed. The half-maximum signal inhibition concentrations (IC50) of cyantraniliprole and chlorantraniliprole by ELISA were 1.2 and 1.5 ng mL-1, respectively. This assay was employed to detect these two insecticides in soil and vegetables. The average recoveries of cyantraniliprole from both bok choy (Brassica chinensis L.) and soil samples were 90-129%, while those of chlorantraniliprole were in a range of 89-120%. The insecticide residues in soil and bok choy, which were collected from plots sprayed with cyantraniliprole and chlorantraniliprole, were simultaneously detected by the resulting ELISA and a high-performance liquid chromatography (HPLC) method, showing a satisfactory correlation. Higher concentrations of chlorantraniliprole than cyantraniliprole were detected in soil and vegetables, which indicates the longer persistence of chlorantraniliprole in the environment.

Detection of ryanodine receptor target-site mutations in diamide insecticide-resistant Spodoptera frugiperda in China.

Spodoptera frugiperda (Lepidoptera: Noctuidae) is a widely distributed pest of corn. Since it invaded China in 2018, it has caused serious damage to local corn production. Chlorantraniliprole, an anthranilic diamide insecticide, has been widely used to control lepidopteran pests. Tetrachloropyramid is a new allosteric modulator insecticide developed based on chlorantraniliprole, so it has a similar mechanism and insecticidal effect. In this study, we investigated resistance levels to chlorantraniliprole and tetrachloropyramid in S. frugiperda from 13 populations in China. Among the populations tested, the relative highest resistance to chlorantraniliprole occurred in the Guangzhou population, and the most susceptible to chlorantraniliprole was found in the Wuhan population. The lethal dosage LD50 value of the Guangzhou population against chlorantraniliprole was 27.8-fold higher than that of the Wuhan population. Minimal differences were observed among S. frugiperda populations in terms of sensitivity to tetrachloropyramid. Heterozygous mutations at the I4734 site of the ryanodine receptor (RyR) were found, while no mutations were found in the G4891 site. The mutations were detected in only two of the 786 individuals analyzed, one from the Qinzhou population and other from the Anshun population (frequency below 2% in both cases). There were no significant differences in the expression levels of RyR between Guangzhou and Wuhan populations. In summary, our results indicate that: (i) S. frugiperda has low resistance levels to diamide insecticides in China; and (ii) the differences in relative resistance among the 13 populations analyzed are not caused by the mutations in RyR or the expression of RyR.

Distributions of nutrients and avenanthramides within oat grain and effects on pearled kernel composition.

Hulled Reins and hulless Lamont oats were dehulled and/or sequentially abraded to produce ten pearling fines and corresponding pearled kernels. Contents of nutrients (protein, oil, starch, beta-glucan, ash and other carbohydrates) and avenanthramides (AVA) 2p, 2c, 2f, and 5p in processing fractions and starting grains were measured. Results show that distribution patterns of nutrients varied with individual nutrients, but those of AVAs varied with variety and individual AVAs. In both varieties, from the surface to inner endosperms, protein and oil increased then decreased; ash and other carbohydrates decreased; starch increased; and beta-glucan unchanged except for the surface area. In Lamont oat, the four AVAs decreased, but in Reins oat, AVA 2p decreased while 2c, 2f and 5p increased, then decreased. Compared to whole grain, pearled oats not only contained lower AVAs, protein, oil, ash, and other carbohydrates and higher beta-glucan and starch but also had a different AVA composition.

Characterization and antioxidant activity of avenanthramides from selected oat lines developed by mutagenesis technique.

From a mutagenized oat population, produced by ethyl methanesulfonate mutagenesis, hulled grains from 17 lines with elevated avenanthramide (AVN) content were selected and their AVN structures, concentrations and antioxidant potentials were determined by HPLC-MS2 and HPLC equipped with an on-line ABTS+ antioxidant detection system. The data obtained showed qualitative and quantitative differences in the synthesis of AVNs in the different lines, with a total AVN concentration up to 227.5 µg/g oat seed flour in the highest line, compared with 78.2 µg/g seed in the commercial line, SW Belinda. In total, 25 different AVNs were identified with avenanthramide B structures being among the most abundant, and AVN C structures having the highest antioxidant activity. The findings indicate the potential of oat mutagenesis in combination with a high precision biochemical selection method for the generation of stable mutagenized lines with a high concentration of total and/or individual AVNs in the oat seed grain.

Role of climate change variables (standing water and rainfall) on dissipation of chlorantraniliprole from a simulated rice ecosystem.

Chlorantraniliprole (CAP) is extensively used for rice pest management. Lack of information on the role of standing water and amount and timing of rainfall on CAP dissipation in rice ecosystem could hamper its prospective use. Present study was performed to investigate the effects of different water regimes (saturated, 5 and 10 cm standing water) and simulated rainfall (40 and 100 mm occurred at 4, 8 and 24 h after CAP application) on leaching, surface runoff and dissipation of CAP into components of rice ecosystem. The results showed highest concentration of CAP residues in soil and plant under saturated condition followed by 5 and 10 cm standing water conditions. Whereas, the highest concentration of CAP in leachates was detected under 10 cm standing water (12.19 ng mL-1). The results revealed large amount of leaching (21.99 ng mL-1) and surface runoff (42.25 ng mL-1) losses of CAP when 100 mm rainfall occurred at 4 h after pesticide application. The total quantity of CAP residues in soil and plant was highest when rainfall occurred at 24 h after pesticide application under both the rainfall amounts. Water stagnation and high intensity rainfall occurred shortly after pesticide application will contribute to pesticide loss to non-target sites through surface run-off and leaching. There will be less pesticide available in soil for plant uptake which may not be sufficient to kill the target organisms.

Persistence and degradation of cyantraniliprole in soil under the influence of varying light sources, temperatures, moisture regimes and carbon dioxide levels.

In the present work, persistence and degradation of cyantraniliprole, a leading anthranilic diamide pesticide against sucking insect pests, in inceptisol soil has been studied. Effect of various factors like light source (UV-light, sunlight and dark), temperature (5, 25 and 37 °C), moisture regime (dry, field capacity and submerged) and carbon dioxide level (415 and 625 µL L-1) on dissipation was also evaluated. Formation of IN-J9Z38, a major metabolite of cyantraniliprole, was monitored in different treatments. Samples were processed as per QuEChERS method and analysis was done by HPLC-PDA. Matrix matched calibration curve, prepared in the range 0.001-10 mg L-1, indicated very good linearity (R2 > 0.99) and sensitivity (instrument limit of detection 0.001 mg L-1). Cyantraniliprole residues dissipated with time and 47.7%-98.8% dissipation was recorded on 90th day in different treatments. Minimum half-life of cyantraniliprole, i.e. 8.7 days was recorded at elevated CO2 level (625 ± 5 µL L-1) while its maximum half-life of 86.6 days was recorded at 5 °C. Metabolite IN-J9Z38 started forming from zero-day and reached the maximum on 15th to 60th day. Microbial biomass carbon, as an index of microbial activity of soil, correlated well with the degradation of cyantraniliprole.

Development and validation of a method for the analysis of five diamide insecticides in edible mushrooms using modified QuEChERS and HPLC-MS/MS.

In this study, a new method for simultaneous determination of cyantraniliprole, chlorantraniliprole, tetrachlorantraniliprole, cyclaniliprole and flubendiamide in edible mushrooms by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) combined with a modified QuEChERS procedure. The samples were extracted using acetonitrile and then cleaned up by primary secondary amine (PSA) and octadecylsilane (C18). The determination of these insecticides was achieved in less than 5 min using an electrospray ionization source in positive mode (ESI+) for cyantraniliprole and chlorantraniliprole, while negative mode (ESI-) for tetrachlorantraniliprole, cyclaniliprole and flubendiamide. The linearities of the calibrations for all target compounds were acceptable (R2 ≥ 0.9922). The limits of detection and quantification were 0.05-2 µg kg-1 and 5 µg kg-1, respectively. Acceptable recoveries (73.5-110.2%) were acquired for these insecticides with RSDs less than 12.7%. The results demonstrated that the proposed method was effective and convenient for the determination of these insecticides in edible mushrooms.

Quantum Yield for the Aqueous Photochemical Degradation of Chlorantraniliprole and Simulation of Its Environmental Fate in a Model California Rice Field.

The photochemical degradation of chlorantraniliprole (3-bromo-N-[4-chloro-2-methyl-6-(methylcarbamoyl)phenyl]-1-(3-chloro-2-pyridine-2-yl)-1H-pyrazole-5-carboxamide; CAP) was characterized under simulated solar light with 2-nitrobenzaldehyde (2NB) actinometry. Overall, aqueous CAP degraded quickly via direct photodegradation with no significant difference observed between high-purity water and filtered rice field water. The 24-h average half-life normalized to summer sunlight using 2NB was 34.5 ± 4.0 h (jCAP,env = 0.020 ± 0.0023 h-1 , n = 3), and the calculated apparent quantum yield in simulated sunlight was 0.0099 ± 0.00060. These new values were used-alongside previously characterized data for air/and soil/water partitioning, degradation in soil, and hydrolysis-in the Pesticides in Flooded Applications Model to simulate CAP dissipation in a model California (USA) rice field. The model estimates an environmental half-life of 26 d in the aqueous phase, but the bulk of applied CAP remains in the benthic zone and degrades, with estimated half-lives of 29 and 92 d in flooded and drained fields, respectively. Environ Toxicol Chem 2020;39:1929-1935. © 2020 SETAC.

Residue and toxicity of cyantraniliprole and its main metabolite J9Z38 in soil-earthworm microcosms.

As part of a new generation of diamide insecticides, cyantraniliprole has broad application prospects. In the present study, a QuEChERS-UPLC-MS/MS method was established to determine the residues of cyantraniliprole and its main metabolite J9Z38 in soil and earthworms. Moreover, the accumulation and toxicity of cyantraniliprole and J9Z38 in earthworms were evaluated. The present results show that the detection method of cyantraniliprole and J9Z38 has high sensitivity and accuracy, which could be used for the accurate quantification of cyantraniliprole and J9Z38 residues in soil and earthworms. Additionally, cyantraniliprole degraded faster than its main metabolite J9Z38 in the artificial soil. Moreover, the bioenrichment efficiency of cyantraniliprole was higher than J9Z38. The toxicity test result showed that cyantraniliprole and J9Z38 could induce oxidative stress effect in earthworms from 5.0 mg/kg, finally resulting in cellular damage. Moreover, the oxidative damage degree induced by cyantraniliprole was higher than J9Z38. Combining the results of residue test and toxicity test, although cyantraniliprole degraded faster than its main metabolite J9Z38 in the artificial soil, its risk to earthworms was higher than J9Z38.

Comprehensive analysis of oat avenanthramides using hybrid quadrupole-Orbitrap mass spectrometry: Possible detection of new compounds.

RATIONALE: Avenanthramides (AVNs) are constituents unique to oats and have many outstanding health benefits. AVNs are antioxidants and possess anti-inflammatory, antifungal and antibacterial activity. The number of known AVNs increased recently because of the latest developments in high-resolution tandem mass spectrometry (HRMS/MS) techniques. METHODS: Oat seed extract from 10 oat cultivars was analysed using ultra-high-performance liquid chromatography (UHPLC) and Q Exactive hybrid quadrupole-Orbitrap mass spectrometry (HRMS/MS) with positive heated electrospray ionization. RESULTS: Thirty-five AVNs were identified and characterized in seed extracts, and the structures of 10 novel AVNs were tentatively elucidated, among which were AVNs bearing a cinamoyl or sinapoyl moiety. These AVNs are reported in oats for the first time. The method was validated using AVN standards (AVNs 2c, 2f and 2p), with limits of detection and quantitation at low picomole levels. Recovery of AVN standards varied from 83% to 106%, and relative standard deviations ranged from 2% to 9%. The total AVNs in the selected oat varieties ranged from 36.0 to 302.5 µg/g (dry weight), with AVN 2c, AVN 2f and AVN 2p representing approximately 65%-70% of that total. CONCLUSIONS: Our comprehensive method for detecting the full avenanthramide spectrum can contribute to better understanding the chemical and biological properties of individual AVNs for utilization in developing new oat cultivars and novel functional foods.

Unexpected drug residuals in human milk in Ankara, capital of Turkey.

BACKGROUND: Breast milk is a natural and unique nutrient for optimum growth and development of the newborn. The aim of this study was to investigate the presence of unpredictable drug residues in mothers' milk and the relationship between drug residues and maternal-infant characteristics. METHODS: In a descriptive study, breastfed infants under 3 months of age and their mothers who applied for child health monitoring were enrolled for the study. Information forms were completed for maternal-infant characteristics, breastfeeding problems, crying and sleep characteristics of infants. Maternal and infant anthropometric measurements and maternal milk sample were taken. Edinburgh Postpartum Depression Scale was applied to mothers. RANDOX Infiniplex kit for milk was used for residual analysis. RESULTS: Overall, 90 volunteer mothers and their breastfed infants were taken into the study and the mean age of the mothers and their infants was 31.5 ± 4.2 years and 57.8 ± 18.1 days, respectively. Anti-inflammatory drug residues in breast milk were detected in 30.0% of mothers and all had tolfenamic acid. Overall, 94.4% had quinolone, 93.3% beta-lactam, 31.1% aminoglycoside and 13.3% polymycin residues. Drugs used during pregnancy or lactation period were not affected by the presence of residues. Edinburgh postpartum depression scores of mothers and crying and sleeping problems of infants were similar in cases with and without drug residues in breast milk. When controlling confounding factors, maternal body mass index alterations were detected to be significantly lower in mothers with anti-inflammatory drug residues in breast milk than in their counterparts (p = 0.017). CONCLUSIONS: Our study suggests that there are unpredictable drug residues in the milk of many mothers. Anti-inflammatory drug exposure might affect maternal weight change during the postpartum period. Further studies are required to evaluate the impact of drug residues on maternal and infant health.

Dissipation of the Insecticide Cyantraniliprole and Its Metabolite IN-J9Z38 in Proso Millet during Cultivation.

The dissipation patterns of cyantraniliprole and its metabolite IN-J9Z38 were investigated using proso millet (Panicum miliaceum) under open-field conditions to establish a pre-harvest interval. A simple and sensitive analytical method was developed for analyzing residues using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) for multiple reaction monitoring of target compounds. The analytical method was validated in terms of the instrumental limit of quantitation, method limit of quantitation, linearity, accuracy, and precision. The method was successfully applied to the analysis of cyantraniliprole and IN-J9Z38 residues in the field samples of four plots, which were treated twice with an oil dispersion formulation, according to the date of pesticide treatment before harvest. In the case of cyantraniliprole in grain and straw, there was a 91.1 and 89.1% decrease, respectively, from the initial residues (14-7 days) to the final plot (40-30 days before harvest). However, IN-J9Z38 gradually increased over time, indicating that cyantraniliprole transformed into IN-J9Z38 during cultivation. The biological half-lives of total cyantraniliprole were 11.3 and 9.4 days for grain and straw, respectively. The results obtained in this study will inform regulation and management of pesticide use for the minor crop proso millet.

A simple method to discriminate Guangchenpi and Chenpi by high-performance thin-layer chromatography and high-performance liquid chromatography based on analysis of dimethyl anthranilate.

Citri Reticulatae Pericarpium (CRP), the dried pericarp of Citrus reticulata Blanco, can be divided into "Guangchenpi" (GCP, the dried pericarps derived from Citrus reticulata 'Chachi') and "Chenpi" (CP, the dried pericarps derived from other cultivars of Citrus reticulata Blanco). To discriminate between GCP and CP, a simple and reliable high-performance thin-layer chromatography (HPTLC) method was firstly developed to analyze the volatile compound dimethyl anthranilate, and a high-performance liquid chromatography (HPLC) method was established to simultaneously quantify dimethyl anthranilate and three predominant flavonoids (hesperidin, nobiletin and tangeretin) in CRP samples. Both the HPTLC analysis and HPLC-orthogonal partial least squares discrimination analysis (OPLS-DA) indicated that GCP can be effectively distinguished from CP based on analysis of dimethyl anthranilate. Our results indicated that dimethyl anthranilate can be used as a marker compound for discrimination of GCP and CP. This work provided a convenient approach which might be applied for quality evaluation of CRP.

Dissipation Kinetics and the Pre-Harvest Residue Limits of Acetamiprid and Chlorantraniliprole in Kimchi Cabbage Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

The dissipation behaviors of acetamiprid and chlorantraniliprole in kimchi cabbages were studied under open-field conditions. A simple and rapid analytical method was developed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The multiple reaction monitoring (MRM) conditions of two pesticides were optimized to quantify and identify the pesticide residues. Sample preparation was performed by the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. Average recovery rates at the different spiked levels (0.05 and 0.25 mg/kg) were in the range of 103.6-113.9% (acetamiprid) and 80.8-91.2% (chlorantraniliprole), and the relative standard deviations were ≤4.3% for all. The dissipation kinetics were assessed using first-order equations after spraying acetamiprid and chlorantraniliprole individually on kimchi cabbages. The biological half-lives in field 1 and 2 were 5.2 and 6.3 days (acetamiprid) and 10.0 and 15.2 days (chlorantraniliprole), respectively. Based on the dissipation equations, the pre-harvest residue limits (PHRLs) corresponding to each day before harvest were suggested as the guidelines to meet the MRL on harvest day. It was also predicted that the terminal residues observed after multiple sprayings (three and seven days) would be below the MRL when harvested, in compliance with the established pre-harvest intervals.

Oat germination and ultrafiltration process improves the polyphenol and avenanthramide contents with protective effect in oxidative-damaged HepG2 cells.

Oat is the nutritious crop containing various compounds with antioxidant properties, such as polyphenols. In this study, we investigated the effect of germination and ultrafiltration process on polyphenol and avenanthramide contents in oat as well as their cytoprotective effect. Germination of oat for 48 hr significantly increased avenanthramide (5.5 to 11.3 mg/g) and polyphenol (115 to 155 mg GAE/g) contents. The compounds were more concentrated after ultrafiltration using 10 kDa membranes (polyphenol, 206 GAE/g; avenanthramide, 18 mg/g). In addition, oat extracts significantly reduced the cellular ROS level against tert-butyl hydroperoxide (t-BHP) stimulation in HepG2 cells. In the mechanistic study, oat extracts induced Nrf2 translocation to the nucleus by inhibition of Keap1 expression, resulting into upregulation of γ-GCS and NQO1. In conclusion, oat germination and ultrafiltration processes increased the polyphenol content, including that of avenanthramide. These extracts protected cells from t-BHP by radical scavenging activities and induced Nrf2 pathway activation. PRACTICAL APPLICATIONS: This study presents the method for avenanthramide-concentrated extract which is unique bioactive compounds in oat. In addition, antioxidant activity and their mechanisms of the avenanthramide-enriched extracts were evaluated. The polyphenol compounds including avenanthramide were found to increase after germination and ultrafiltration, thereby improving the radical scavenging ability. These results can be utilized as data for the development of health-promoting materials using oats.