Determination of Flunixin and 5-Hydroxy Flunixin Residues in Livestock and Fishery Products Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

Flunixin is a veterinary nonsteroidal anti-inflammatory agent whose residues have been investigated in their original form within tissues such as muscle and liver. However, flunixin remains in milk as a metabolite, and 5-hydroxy flunixin has been used as the primary marker for its surveillance. This study aimed to develop a quantitative method for detecting flunixin and 5-hydroxy flunixin in milk and to strengthen the monitoring system by applying to other livestock and fishery products. Two different methods were compared, and the target compounds were extracted from milk using an organic solvent, purified with C18, concentrated, and reconstituted using a methanol-based solvent. Following filtering, the final sample was analyzed using liquid chromatography- tandem mass spectrometry. Method 1 is environmentally friendly due to the low use of reagents and is based on a multi-residue, multi-class analysis method approved by the Ministry of Food and Drug Safety. The accuracy and precision of both methods were 84.6%-115% and 0.7%-9.3%, respectively. Owing to the low matrix effect in milk and its convenience, Method 1 was evaluated for other matrices (beef, chicken, egg, flatfish, and shrimp) and its recovery and coefficient of variation are sufficient according to the Codex criteria (CAC/GL 71-2009). The limits of detection and quantification were 2-8 and 5-27 µg/kg for flunixin and 2-10 and 6-33 µg/kg for 5-hydroxy flunixin, respectively. This study can be used as a monitoring method for a positive list system that regulates veterinary drug residues for all livestock and fisheries products.

Re-evaluation of a microbiological acceptable daily intake for tylosin based on its impact on human intestinal microflora.

As veterinary drugs available for fish is very restricted, there is growing trials for repurposing livestock drugs as aquatic animal drugs. Tylosin is one of the most effective antibiotics to treat bacterial infections approved for livestock, and would be used in fish. Hence, we investigated the toxicological and microbiological aspects of tylosin to establish health-based guidance value (HBGV) and maximum residue limit (MRL) in fishes, and reevaluated the microbiological acceptable daily intake (mADI) based on updated relevant data and international guildeline. Lastly, exposure assessment was performed to confirm the appropriateness of MRL. By investigating available microbiologcial studies on tylosin, the microbiological point of departure was determined as 0.308 µg/mL, which was mean 50% minimum inhibitory concentration (MIC50), obtained from the Food Safety Committee of Japan (FSCJ) evaluation report. Furthermore, as a factor for the derivation of mADI, the volume of colon content was recently changed to 500 mL in compliance with the International Cooperation on Harmonization of Technical Requirements for Registration of Veterinary Medicinal Products (VICH) guidelines. This was previously defined as the mass of colon content (220 g). We applied correction factor 0.224 to the mean MIC50 for tylosin in the equation of mADI, since the drug is transformed to metabolites with reduced activity prior to entering the colon and bound to fecal materials within the colon of human. The mADI was evaluated as 0.01 mg/kg bw/day. Finally, the hazard index, calculated by dividing the estimated chronic dietary exposure by mADI, did not exceed 100%, suggesting that chronic dietary exposure to tylosin residues from veterinary use was unlikely to be a public health concern. Overall, this study contributes significantly in updating HBGV by application of the concept of mADI for the first time in Korea based on the revised microbiological risk assessment guidelines and in providing scientific rationale for the risk management of veterinary drug residues in food. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-023-00179-z.

Multiclass Method for the Determination of Anthelmintic and Antiprotozoal Drugs in Livestock Products by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

The objective of this study was to establish a multi-residue quantitative method for the analysis of anthelmintic and antiprotozoal drugs in various livestock products (beef, pork, and chicken) using ultra-high-performance liquid chromatography-tandem mass spectrometry. Each compound performed validation at three different levels i.e., 0.5, 1, and 2× the maximum residue limit according to the CODEX guidelines (CAC/GL 71-2009). This study was conducted according to the modified quick, easy, cheap, effective, rugged, and safe procedure. The matrix-matched calibrations gave correlation coefficients >0.98, and the obtained recoveries were in the range of 60.2%-119.9%, with coefficients of variation ≤32.0%. Furthermore, the detection and quantification limits of the method were in the ranges of 0.03-3.2 and 0.1-9.7 µg/kg, respectively. Moreover, a survey of residual anthelmintic and antiprotozoal drugs was also carried out in 30 samples of beef, pork, and chicken collected in Korea. Toltrazuril sulfone was detected in all three samples. Thus, our results indicated that the developed method is suitable for determining the anthelmintic and antiprotozoal drug contents in livestock products.

Ultra-fast PCR method for the distinguishing between Miichthys miiuy and Sciaenops ocellatus.

The mi-iuy croaker Miichthys miiuy has immense commercial value in the Republic of Korea. The red drum Sciaenops ocellatus is widely produced by aquaculture, although its price is approximately 25% that of M. miiuy. S. ocellatus has black spots on its tail, enabling it to be distinguished from M. miiuy based on appearance. However, identifying S. ocellatus after simple processing steps, such as skin removal and dicing, is difficult. Certain traders misrepresent and sell S. ocellatus as M. miiuy or cultured M. miiuy for illegal economical gain. Therefore, an accurate and rapid identification method is required to distinguish between M. miiuy and S. ocellatus in the field. Here, a method for rapid field identification was developed based on species-specific primers using a portable ultra-fast PCR instrument. The ultra-fast real-time PCR method can complete the entire analytical procedure, including DNA isolation, amplification, and detection, within 30 min, thus maintaining the accuracy of identifying M. miiuy and S. ocellatus products on site. Forty-nine commercial products were tested, and all samples were successfully identified. Thus, the developed method is rapid, efficient tool for ensuring consumer protection. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00954-4.

Authentication of tejocote (Crataegus mexicana) dietary supplements based on DNA barcoding and chemical profiling.

Tejocote (Crataegus mexicana, Mexican hawthorn), known as a weight-loss supplement, has been marketed online and is easily available for overseas direct purchase. Alipotec (brand name) is known as one of the most popular products containing tejocote in Mexico and other countries. However, adverse effects have been reported by users of these supplements. Therefore it is necessary to find the reason for the side effect. Dietary supplement samples labelled as containing tejocote were analysed using mass spectrometry and DNA barcoding analysis. Our results demonstrate that Alipotec samples contained ingredients from different species, yellow oleander instead of tejocote. The rpoB barcode region was able to differentiate between tejocote and yellow oleander species. Moreover, it was also observed that three compounds, including thevetin B, neriifolin, and digitoxigenin, clearly distinguish between tejocote and yellow oleander samples. This is the first and preliminary investigation to use an integrated approach of both chemical and genomic profiling for the authentication of dietary supplement containing tejocote.

Multi-Class Determination of 64 Illicit Compounds in Dietary Supplements Using Liquid Chromatography-Tandem Mass Spectrometry.

In this work, liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for screening and confirmation of 64 illicit compounds in dietary supplements. The target compounds were illegally used pharmaceutical drugs, prohibited compounds, and not authorized ingredients for different therapeutics (sexual enhancement, weight loss, muscular strengthening, and relaxing products). The validation procedure was performed to evaluate selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision according to the Association of Official Analytical Chemists guidelines. The linearity was >0.98 in the range of 0.5-200 µg L-1. The LOQs were in the range 1-10 µg kg-1 for all target compounds. The accuracy (expressed as recovery) was 78.5-114%. The precision (expressed as the relative standard deviation) was below 9.15%. The developed method was applied for the determination of illicit compounds in dietary supplements collected from websites. As a result, the total detection rate was 13.5% (27 samples detected in 200 samples). The concentrations of detected samples ranged from 0.51 to 226 mg g-1. The proposed methodology is suitable for monitoring the adulteration of illicit compounds in dietary supplements.

Cuvette-Type LSPR Sensor for Highly Sensitive Detection of Melamine in Infant Formulas.

The globalization of food distribution has made necessary to secure safe products to the general consumers through the rapid detection of harmful additives on the field. For this purpose, we developed a cuvette-type localized surface plasmon resonance (LSPR) sensor that can be easily used by consumers with conventional ultraviolet-visible light spectrophotometer for in-situ measurements. Gold nanoparticles were uniformly deposited on a transparent substrate via a self-assembly method to obtain a plasmonically active chip, and the chemical receptor p-nitroaniline (p-NA) was functionalized to stabilize the device sensitivity under external temperature and pH conditions. The fabricated chip was fixed onto a support and combined with a cuvette-type LSPR sensor. To evaluate the applicability of this sensor on the field, sensitivity and quantitative analysis experiments were conducted onto melamine as a model sample from harmful food additives. Under optimal reaction condition (2 mM p-NA for 20 min), we achieved an excellent detection limit (0.01 ppb) and a dynamic range allowing quantitative analysis over a wide concentration range (0.1-1000 ppb) from commercially available milk powder samples.

Veterinary drug, 17ß-trenbolone promotes the proliferation of human prostate cancer cell line through the Akt/AR signaling pathway.

Trenbolone acetate (TBA) is a synthetic anabolic steroidal growth factor that is used for rapid muscle development in cattle. The absorbed TBA is hydrolyzed to the active form, 17ß-trenbolone (17 TB; 17ß-hydroxy-estra-4,9,11-trien-3-one) in meat and milk products, which can cause adverse health effects in humans. Similar to 5α-dihydrotestosterone (DHT), 17 TB was reported to exhibit endocrine disrupting effects on animals and humans due to its androgenic effect via binding to the androgen receptor. The purpose of this study is to investigate the molecular mechanism of cell proliferation in prostate cancer (PCa) cells treated with 17 TB. We found that 17 TB induces AR-dependent cell proliferation in the human prostate cancer cell line, 22Rv1 in a concentration dependent manner. Treatment with 17 TB increased the expression of cell cycle regulatory proteins, cyclin D2/CDK-4 and cyclin E/CDK-2, whereas the expression of p27 was down-regulated. Furthermore, phosphorylation of Rb and activation of E2F were also induced, which suggests the activation of cyclin D2/CDK-4 and cyclin E/CDK-2 in the cells. When 22Rv1 cells were exposed to 30 pM of 17 TB, which is the effective concentration (EC50) value required to observe proliferative effects on 22Rv1 cells, the expression levels of the phosphorylated forms of Akt and GSK3ß were increased. This study demonstrates that 17 TB induces AR-dependent proliferation through the modulation of cell cycle-related proteins in the Akt signaling pathway. The present study provides an effective methodology for identifying cell proliferation signaling of veterinary drugs that exert AR agonistic effects.

Assessment of androgen receptor agonistic/antagonistic effects on 25 chemicals in household applicants by OECD in vitro stably transfected transcriptional activation assays.

The aim of this study is to assess the androgen receptor (AR) agonistic/antagonistic effects on various chemicals, which are used in household products including cleaning agents and wetted tissues by in vitro OECD test guideline No. 458 (using AR-EcoScreen™ cell line) and the me-too test method (using 22Rv1cell line), which was adopted as OECD project No. 4.99. All chemicals were not determined as AR agonists. However α-dodecyl-ω-hydroxypoly (oxyethylene) and 3-iodo-2-propynyl butylcarbamate have shown a weak AR antagonistic effects with IC50 values of 2.18 ±â€¯0.12 and 4.26 ±â€¯0.17 µg/ml via binding affinity to AR in only 22Rv1/mouse mammary tumor virus using AR transcriptional activation assay, because of their different cytotoxicity on each applied cell line. This report firstly provides information about agonistic/antagonistic effects against human AR of various chemicals including surfactants and biocides by OECD in vitro stably transfected transcriptional activation assays. However, further in vivo and human model studies are needed to confirm their adverse effects.

Preconceptional use of folic acid and knowledge about folic acid among low-income pregnant women in Korea.

BACKGROUND/OBJECTIVES: Folic acid supplementation before pregnancy is known to significantly reduce the risk of having a baby with neural tube defects (NTDs). Therefore, it is important for women to be aware of the effects of folic acid supplementation before pregnancy. The purpose of this study was to investigate the awareness and preconceptional use of folic acid and to assess the current knowledge about folic acid among low-income pregnant women in Korea. SUBJECTS/METHODS: A questionnaire survey was conducted in 2012. Five hundred pregnant women were selected from the waiting list for the Nutriplus program implemented in public health centers using a multistage clustered probability sampling design. Data from 439 women were analyzed after excluding ones with incomplete answers. RESULTS: Among women who responded to the questionnaire, 65.6% had heard of folic acid before pregnancy, and 26.4% reported on the preconceptional use of folic acid. Women with a university degree or higher education were more likely to be aware of folic acid and to take folic acid in the preconception period. In a multivariate logistic regression, when age, education level, household income, employment status, gravidity, parity, and folic acid awareness were included in the model, folic acid awareness was a strong predictor of preconceptional folic acid use. As of interview, 85.4% and 77.7% of women were aware of the NTD-preventive role of folic acid and the appropriate time to take folic acid, respectively. The main sources of information on folic acid were healthcare professionals (41.2%), friends and family members (31.2%), and the media (26.5%). CONCLUSIONS: Our results suggest that public health strategies are needed to increase the preconceptional use of folic acid among Korean women.

Event-specific qualitative and quantitative detection of five genetically modified rice events using a single standard reference molecule.

One novel standard reference plasmid, namely pUC-RICE5, was constructed as a positive control and calibrator for event-specific qualitative and quantitative detection of genetically modified (GM) rice (Bt63, Kemingdao1, Kefeng6, Kefeng8, and LLRice62). pUC-RICE5 contained fragments of a rice-specific endogenous reference gene (sucrose phosphate synthase) as well as the five GM rice events. An existing qualitative PCR assay approach was modified using pUC-RICE5 to create a quantitative method with limits of detection correlating to approximately 1-10 copies of rice haploid genomes. In this quantitative PCR assay, the square regression coefficients ranged from 0.993 to 1.000. The standard deviation and relative standard deviation values for repeatability ranged from 0.02 to 0.22 and 0.10% to 0.67%, respectively. The Ministry of Food and Drug Safety (Korea) validated the method and the results suggest it could be used routinely to identify five GM rice events.

In vitro OECD test methods applied to screen the estrogenic effect of chemicals, used in Korea.

In this study, 27 chemicals found in household products, which became an issue in Korea were screened for the agonistoc and antagonistic effects against human estrogen receptor using official Organization for Economic Cooperation and Development (OECD) in vitro assays, STTA assay using ERα-HeLa-9903 cell line and BG1Luc ER TA assay. In the case of human ER agonist screening by two assays, all tested chemicals did not show agonist effect against ER. In ER antagonist test by BG1Luc ER TA assay, five surfactants α-dodecyl-ω-hydroxypoly(oxyethylene), alcohols C16-18 ethoxylated, nonylphenol, ethoxylated, 3,6,9,12,15,18,21-heptaoxatritriacontan-1-ol, and α-dodecyl-ω-hydroxypoly(oxy-1,2-ethanediyl)) were found to exhibit weak antagonistic activities. The agonist/antagonist effects against human estrogen receptor of various chemicals, used in Korea by OECD test guideline are reported in this study. These results indicated that two OECD in vitro assays will can be applied in Korea by screening of agonistic/antagonistic effects against human ER of various chemicals.

Risk assessment based on urinary bisphenol A levels in the general Korean population.

Bisphenol A (BPA) is a high-volume industrial chemical used in the global production of polycarbonate plastics and epoxy resins, which are used in food and drink containers, such as tableware (plates and mugs). Due to its broad applications, BPA has been detected in human blood, urine and breast milk as well as environmental substances, including water, indoor and outdoor air, and dust. Indeed, exposure to high concentrations of BPA can result in a variety of harmful effects, including reproductive toxicity, through a mechanism of endocrine disruption. Our comparison of reported BPA urinary concentrations among different countries revealed that exposures in Korea may be higher than those in other Asian countries and North America, but lower than or similar to those in European countries. The current study included a total of 2044 eligible subjects of all ages. The subjects were evenly divided between males and females (48.58% and 51.42%, respectively). The geometric mean (GM) of pre-adjusted (adjusted) urinary BPA concentrations was 1.83µg/L (2.01µg/g creatinine) for subjects of all ages, and there was no statistically difference in BPA concentrations between males (1.90µg/L, 1.87µg/g creatinine) and females (1.76µg/L, 2.16µg/g creatinine). Multiple regression analysis revealed only one positive association between creatinine pre-adjusted urinary BPA concentration and age (ß=-0.0868, p<0.001). The 95th percentile levels of 24-hour recall (HR), food frequency questionnaires (FFQ) and estimated daily intake (EDI) through urinary BPA concentrations were 0.14, 0.13, and 0.22µg/kg bw/day, respectively. According to the Ministry of Food and Drug Safety (MFDS), a tolerable daily intake (tDI) of 20µg/kg bw/day was established for BPA from the available toxicological data. Recently, the European Food Safety Authority (EFSA) established a temporary TDI of 4µg/kg bw/day based on current toxicological data. By comparing these TDIs with subjects' exposure, we conclude that there are no health concerns for any age group as a result of current levels of dietary exposure to BPA.

Bisphenol A exerts estrogenic effects by modulating CDK1/2 and p38 MAP kinase activity.

Bisphenol A (BPA) is considered to be an endocrine disruptor, but the mechanisms by which it disrupts endocrine functions are poorly understood. Here, we have shown that BPA binds both estrogen receptor (ER)-α and ER-beta (ER-ß) using a fluorescence polarization competitive binding assay. In addition, we found that BPA induced cell proliferation by modulating cell cycle-related genes in the MCF-7 human mammary cancer cell line. Moreover, using a BG1 luciferase ER transactivation assay, we found that BPA has estrogenic activity. Modulating the MAPK pathway by using an ERK inhibitor (PD98059) or a JNK inhibitor (SP600125) had no effect on the ability of BPA to induce estrogenic activity. However, the antiestrogen, ICI 182,780, and the p38 inhibitor, PD 169316 successfully blocked BPA-induced estrogenic activity. Our findings suggest that BPA mimics ER-dependent estrogenic activity by targeting proteins that regulate the cell cycle and p38 MAPK.

Comparison of dietary food and nutrient intakes by supplement use in pregnant and lactating women in Seoul.

This study was performed to compare the dietary food and nutrient intakes according to supplement use in pregnant and lactating women in Seoul. The subjects were composed of 201 pregnant and 104 lactating women, and their dietary food intake was assessed using the 24-h recall method. General information on demographic and socioeconomic factors, as well as health-related behaviors, including the use of dietary supplements, were collected. About 88% and 60% of the pregnant and lactating women took dietary supplements, respectively. The proportion of dietary supplements used was higher in pregnant women with a higher level of education. After adjusting for potential confounders, among the pregnant women, supplement users were found to consume 45% more vegetables, and those among the lactating women were found to consume 96% more beans and 58% more vegetables. The intakes of dietary fiber and ß-carotene among supplement users were higher than those of non-users, by 23% and 39%, respectively. Among pregnant women, the proportion of women with an intake of vitamin C (from diet alone) below the estimated average requirements (EAR) was lower among supplement users [users (44%) vs. non-users (68%)], and the proportion of lactating women with intakes of iron (from diet alone) below the EAR was lower among supplement users [usesr (17%) vs. non-users (38%)]. These results suggest that among pregnant and lactating women, those who do not use dietary supplements tend to have a lower intake of healthy foods, such as beans and vegetables, as well as a lower intake of dietary fiber and ß-carotene, which are abundant in these foods, and non-users are more likely than users to have inadequate intake of micro-nutrient such as vitamin C and iron.