Carry-over of pyrrolizidine alkaloids from feed to milk in dairy cows

Dose-response study on the transfer of pyrrolizidine alkaloids from a tansy ragwort extract (Jacobaea vulgaris Gaertn.) to bovine milk

Ragworts like tansy ragwort (J. vulgaris Gaertn., syn. Senecio jacobaea L.) contain hepatotoxic and cancerogenic pyrrolizidine alkaloids (PA) and their corresponding pyrrolizidine alkaloid N-oxides (PANO). Due to increasing spread of ragworts (Jacobaea spp.) PA/PANO may pose a health risk to animals and humans consuming contaminated feed and food. Therefore, the aim of the present study was to investigate the transfer of individual PA/PANO originating from a well-defined PA/PANO extract into the milk of dairy cows. For this objective, 16 German Holstein cows were assigned to four treatment groups (n = 4) in a 28-day dose-response study. Administration into the reticulorumen was performed daily by gavage after the morning milking. Three groups received different amounts of the J. vulgaris extract resulting in a PA/PANO exposure of 0.47, 0.95, or 1.91 mg PA/PANO/kg body weight/day, respectively. Furthermore, a control group received molasses to account for the sugar content of the used PA/PANO extract. While the composition of the PA/PANO extract was more diverse, the PA/PANO pattern in milk was dominated by the PA in their free base form. It was shown that mainly PA considered stable in the rumen environment were transferred into the milk. The main compounds in milk were jacoline (74.3 ± 2.4% of the PA/PANO sum), jaconine (11.2 ± 1.3%), and jacobine (7.2 ± 0.6%) with concentrations up to 29.7, 4.65 µg/l, or in the highest exposed group, 3.44 µg/l. There was no dose-dependent effect on the total PA/PANO transfer rate into the milk. The average transfer rate was 0.064 ± 0.005% of the administered content.

A Comprehensive Review on the Biogenic Amines in Cheeses: Their Origin, Chemical Characteristics, Hazard and Reduction Strategies

Most of the biogenic amines are naturally found in fermented foods as a consequence of amino acid decarboxylation. Their formation is ascribable to microorganisms (starters, contaminants and autochthonous) present in the food matrix. The concentration of these molecules is important for food security reasons, as they are involved in food poisoning illnesses. The most frequent amines found in foods are histamine, putrescine, cadaverine, tyramine, tryptamine, phenylethylamine, spermine and spermidine. One of the most risk-prone foods are cheeses, mostly ripened ones, which could easily accumulate amines due to their peculiar manufacturing process and ripening. Cheeses represent a pivotal food in our diet, providing for nutrients such as amino acids, calcium, vitamins and others; thus, since they are widely consumed, it is important to evaluate the presence of toxic molecules to avoid consumers' poisoning. This review aimed to gather general information on the role of biogenic amines, their formation, the health issues and the microorganisms and processes that produce/reduce them, with a focus on their content in different types of cheese (from soft to hard cheeses) and the biotic and abiotic factors that influence their formation or reduction and concentration. Finally, a multivariate analysis was performed on the biogenic amine content, derived from data available in the literature, to obtain more information about the factors influencing their presence in cheeses.

Pyrrolizidine alkaloids and tropane alkaloids in milk samples from individual dairy farms of the German federal states of Bavaria and Schleswig-Holstein

1,2-Dehydro-pyrrolizidine alkaloids (PA), their corresponding N-oxides (PANO) and tropane alkaloids (TA), are toxic plant metabolites. If plant material, containing these toxins, is present in the feed of dairy cows these toxins can be transferred into milk. Here, milk was sampled directly from dairy farms in the German federal states of Bavaria and Schleswig-Holstein in 2020-2022 in order to investigate a possible contamination of milk at the production stage. In total, 228 milk samples were analysed for 54 PA/PANO and two TA by a sensitive LC-ESI-MS/MS method. In addition, a subset of milk samples (n = 85) was independently analysed for TA by a cooperating laboratory for verification. PA/PANO were found in 26 samples (11%) with a low median sum content of the contaminated samples of 0.024 µg/L. The highest level of contamination was 5.6 µg/L. Senecionine-, lycopsamine- and heliotrine-type PA/PANO were detected. In four samples (1.8%), atropine was determined up to 0.066 µg/L. The toxin levels in the milk samples hardly contributed to the total daily exposure. These data are first-time results on contamination rates and levels occurring in milk from individual dairy farms, based on a large sample number.

Short-term exposure of dairy cows to pyrrolizidine alkaloids from tansy ragwort (Jacobaea vulgaris Gaertn.): effects on organs and indicators of energy metabolism

Preserved feed from meadows contaminated with ragwort (Jacobaea vulgaris, Gaertn.) may expose livestock to pyrrolizidine alkaloids (PA). Dairy cows are considered to be very susceptible animals and a PA ingestion can lead to liver and further organ damages and even death. Due to the lack of data, the present study aimed to evaluate critical PA doses based on organ effects, with a special focus on liver lesions and on indicators of energy metabolism. Therefore, 16 dairy cows (n = 4 per group) were exposed to increasing PA doses (group: CONMolasses: <0.001 mg PA/kg body weight (BW)/day (d); PA1: 0.47 mg PA/kg BW/d; PA2: 0.95 mg PA/kg BW/d; PA3: 1.91 mg PA/kg BW/d) for 28 days. Constant dosing was ensured by a defined PA extract administered orally once daily. Histological examinations of the livers showed infiltration by immune cells, higher proportions of apoptotic cells and enlargement of hepatocyte nuclei in the highest exposed group. In addition, bile volume increased with PA dose, which may indicate a cholestasis. Despite the signs of incipient liver damage, liver lipid content and clinical chemical parameters related to energy metabolism, such as glucose, non-esterified fatty acids and βhydroxybutyrate, remained unaffected. Fat depot masses were also not significantly altered over time, suggesting that PA exposure did not induce a wasting syndrome. The liver showed slight microscopic changes already at a dosage of 0.95 mg PA/kg BW/d. However, the short-term metabolic indicators of energy status, lipolysis and ketogenesis, glucose, NEFA and BHB, as well as changes in fat depot, which serves as a longer-term indicator of lipolysis, remained unaffected in all treatment groups in the chosen scenario. These findings suggest that despite histopathological and clinical-chemical evidence of PA-associated hepatocellular lesions, liver function was not compromised.

Toxins in Botanical Drugs and Plant-derived Food and Feed - from Science to Regulation: A Workshop Review

In September 2022, the 3rd International Workshop on pyrrolizidine alkaloids (PAs) and related phytotoxins was held on-line, entitled 'Toxins in botanical drugs and plant-derived food and feed - from science to regulation'. The workshop focused on new findings about the occurrence, exposure, toxicity, and risk assessment of PAs. In addition, new scientific results related to the risk assessment of alkenylbenzenes, a distinct class of herbal constituents, were presented. The presence of PAs and alkenylbenzenes in plant-derived food, feed, and herbal medicines has raised health concerns with respect to their acute and chronic toxicity but mainly related to the genotoxic and carcinogenic properties of several congeners. The compounds are natural constituents of a variety of plant families and species widely used in medicinal, food, and feed products. Their individual occurrence, levels, and toxic properties, together with the broad range of congeners present in nature, represent a striking challenge to modern toxicology. This review tries to provide an overview of the current knowledge on these compounds and indicates needs and perspectives for future research.

Factors influencing the fate of chemical food safety hazards in the terrestrial circular primary food production system-A comprehensive review

Food safety is recognized as a major hurdle in the transition toward circular food production systems due to the potential reintroduction and accumulation of chemical contaminants in these food systems. Effectively managing these hazardous contaminants in a risk-based manner requires quantitative insights into the factors influencing the presence and fate of contaminants in the entire circular food chain. A systematic literature review was performed to gain an up-to-date overview of the known factors and their influence on the transfer and accumulation of contaminants. This review focused on the terrestrial circular primary food production system, including the pathways between waste- or byproduct-based fertilizers, soil, crops, animal feed, and farmed animals. This review revealed an imbalance in research regarding the different pathways: studies on the soil-to-crop pathway were most abundant. The factors identified can be categorized as compound-related (intrinsic) factors, such as hydrophobicity, molecular weight, and chain length, and extrinsic factors, such as soil organic matter and carbon, pH, milk yield of cows, crop age, and biomass. Quantitative data on the influence of the identified factors were limited. Most studies quantified the influence of individual factors, whereas only a few studies quantified the combined effect of multiple factors. By providing a holistic insight into the influential factors and the quantification of their influence on the fate of contaminants, this review contributes to the improvement of food safety management for chemical hazards when transitioning to a circular food system.

Simultaneous determination of 15 pyrrolizidine alkaloids and their N-oxides in weeds, soil, fresh tea leaves, and tea: Exploring the pollution source of pyrrolizidine alkaloids in tea

Pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs) are novel contaminants in tea. However, the source of PA/PANO contamination in tea remains unclear. In this study, 15 PAs/PANOs were extracted from plant samples (tea, fresh tea leaves, and weeds) with 0.1 M sulfuric acid and from soil with 0.1 M sulfuric acid methanol after adjusting soil acidity with 0.1 M trisodium citrate. Satisfactory recoveries of PAs/PANOs from four different matrices at 0.02, 0.1, and 0.5 mg kg-1 was 72%-114% with relative standard deviations (RSD) of 0.03%-16%. Seven out of 15 PAs/PANOs were detected in tea purchased from the local market ranging from undetected to 96.2 μg kg-1. Thirteen, three, and four PAs/PANOs were detected in weeds, fresh tea leaves, and soil, respectively. Based on the types of PAs/PANOs detected in the three matrices, it was preliminarily speculated that PAs/PANOs in tea originated from weeds in the tea garden.

Levels, Toxic Effects, and Risk Assessment of Pyrrolizidine Alkaloids in Foods: A Review

Pyrrolizidine alkaloids (PAs) are naturally occurring secondary metabolites of plants. To date, more than 660 types of PAs have been identified from an estimated 6000 plants, and approximately 120 of these PAs are hepatotoxic. As a result of PAs being found in spices, herbal teas, honey, and milk, PAs are considered contaminants in foods, posing a potential risk to human health. Here, we summarize the chemical structure, toxic effects, levels, and regulation of PAs in different countries to provide a better understanding of their toxicity and risk assessment. With recent research on the risk assessment of PAs, this review also discusses the challenges facing this field, aiming to provide a scientific basis for PA toxicity research and safety assessment.

Pyrrolizidine alkaloid contamination of food in Africa: A review of current trends and implications

Pyrrolizidine alkaloids (PAs) contamination of foodstuffs has become a topical issue in recent years on account of its potential hepatotoxicity to consumers. This review therefore highlights human exposure to PAs across Africa, focusing on their occurrence, current trends of food contamination, and their associated health implications. A comprehensive search of peer-scientific literature and relevant databases, PubMed, Google Scholar, Science Direct, Web of Science and Scopus, was conducted from 2001 to 2023 focusing mainly on foodstuffs, including grains, herbs, teas, honey, and livestock products. The findings revealed that PA contamination is a prevalent issue in several African countries, with the primary sources of contamination attributed to the consumption of honey and the use of PA plants as herbs in food preparations. Additionally, poor farming practices have been found to influence the presence and levels of PAs in foodstuffs. To mitigate PA contamination in food and safeguarding public health across the continent, several strategies are proposed, including the implementation of stringent regulatory and quality control measures, adoption of Good Agricultural Practices, and public awareness campaigns to educate producers, consumers and beekeepers about the risks associated with PA-contaminated food products.

Exposure to echimidine impairs the heart development and function of zebrafish larvae

Pyrrolizidine alkaloids (PAs) are a class of phytotoxins that are widely distributed and can be consumed by humans through their daily diets. Echimidine is one of the most abundant PAs, but its safety, particularly its effects on development, is not fully understood. In this study, we used a zebrafish model to assess the developmental toxicity of echimidine. Zebrafish embryos were exposed to echimidine at concentrations of 0.02, 0.2, and 2 mg/L for 96 h. Our study revealed that embryonic exposure to echimidine led to developmental toxicity, characterized by delayed hatching and reduced body length. Additionally, echimidine exposure had a notable impact on heart development in larvae, causing tachycardia and reducing stroke volume (SV)and cardiac output (CO). Upon exposing the transgenic zebrafish strain Tg(cmlc2:EGFP) to echimidine, we observed atrial dilation and thinning of the atrial wall in developing embryos. Moreover, our findings indicated abnormal expression of genes associated with cardiac development (including gata4, tbx5, nkx2.5 and myh6) and genes involved in calcium signaling pathways (such as cacna1aa, cacna1sa, ryr2a, ryr2b, atp2a2a, atp2a2b, slc8a1, slc8a3 and slc8a4a). In summary, our findings demonstrate that echimidine may impair cardiac development and function in zebrafish larvae by disrupting calcium transport, leading to developmental toxicity. These findings provide insights regarding the safety of products containing PAs in food and medicine.

Short-term exposure of dairy cows to pyrrolizidine alkaloids from tansy ragwort (Jacobaea vulgaris Gaertn.): effects on health and performance

The increasing spread of ragworts is observed with concern. Ragworts like tansy ragwort (Jacobaea vulgaris Gaertn.) or marsh ragwort (J. aquatica) contain pyrrolizidine alkaloids (PA) which may induce hepatotoxic effects. Grazing animals usually avoid ragworts if their pasture management is appropriate. Preserved feed prepared from ragworts contaminated meadows may, however, lead to a significant exposure to PA. Previous studies on toxicity of PA for dairy cows revealed inconsistent results due to feeding ragwort plant material which was associated with heterogeneous PA exposure and thus failed to conclusively deduce critical PA doses. Therefore, the aim of the present study was to expose dairy cows (n = 4 per group) in a short-term scenario for 28 days with increasing PA doses (PA1: 0.47 mg PA/kg body weight (BW)/day (d); PA2: 0.95 mg PA/kg BW/d; PA3: 1.91 mg PA/kg BW/d) via oral administration by gavage of a defined PA-extract. While group PA3 was dosed with the PA-extract alone, groups PA2 and PA1 received PA-extracts blended in similar volumes with molasses to provide comparable amounts of sugar. Additionally, two control groups were treated either with water (CONWater) or with molasses (CONMolasses) to assess the effects of sugar without PA interference. While clinical traits including dry matter intake, milking performance, rectal body temperature, ruminal activity and body condition score (BCS) were not influenced by PA exposure, activities of enzymes indicative for liver damages, such as gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH), increased significantly over time at an exposure of 1.91 mg total PA/kg BW/d.

Alkaloids in food: a review of toxicity, analytical methods, occurrence and risk assessments

Alkaloids have been utilized by humans for years. They have diverse applications in pharmaceuticals. They have been proven to be effective in treating a number of diseases. They also form an important part of regular human diets, as they are present in food items, food supplements, diet ingredients and food contaminants. Despite their obvious importance, these alkaloids are toxic to humans. Their toxicity is dependent on a range of factors, such as specific dosage, exposure time and individual properties. Mild toxic effects include nausea, itching and vomiting while chronic effects include paralysis, teratogenicity and death. This review summarizes the published studies on the toxicity, analytical methods, occurrence and risk assessments of six major alkaloid groups that are present in food, namely, ergot, glycoalkaloids, purine, pyrrolizidine, quinolizidine and tropane alkaloids.

[The One Health approach in the context of global commodity chains, crises, and food and feed safety]

The holistic view of food and feed safety, including animal health and environmental conditions, is an important pillar of the One Health approach. The terminology thus clearly goes beyond the prevention of spreading microbiological diseases, in which context it is often understood, and highlights that humans, animals, and the environment as well as their interaction should be considered in a transdisciplinary context.In terms of One Health, this discussion paper focuses less on microbiological risks, but rather on the connection to chemical risks in the food chain. This is illustrated by concrete examples of chemical contaminants (metals, persistent organic contaminants, natural toxins). The mechanisms of input and transfer along the food chain are presented.Minimizing the presence of contaminants and thus exposure requires international and interdisciplinary cooperation in the spirit of the One Health approach. Climate change, pandemics, shortages of raw materials, energy deficiencies, political crises, and environmental disasters can affect the entire food chain from primary production of plant and animal foods to further processing and provision of products to consumers. In addition to changing availability, this can also have an impact on the composition, quality, and safety of food and feed. Based on the effect on global commodity chains, vulnerable and resilient areas along the food chain become visible. In terms of the One Health approach, the aim is to increase safety and resilience along the food chain and to minimize its vulnerability.

Risk assessment of short-term intake of pyrrolizidine alkaloids in food: derivation of an acute reference dose

Pyrrolizidine alkaloids (PA) are phytochemicals that are known to act as human hepatotoxins and are also considered to be genotoxic carcinogens. Several plant-derived foods are frequently contaminated with PA, like teas and herbal infusions, spices and herbs or certain food supplements. With respect to the chronic toxicity of PA, the carcinogenic potential of PA is generally regarded as the critical toxicological effect. The risk assessment of the short-term toxicity of PA, however, is internationally less consistent. The characteristic pathological syndrome of acute PA toxicity is hepatic veno-occlusive disease. High PA exposure levels may lead to liver failure and even death as documented by several case reports. In the present report, we suggest a risk assessment approach for the derivation of an acute reference dose (ARfD) for PA of 1 µg/kg body weight per day based on a sub-acute animal toxicity study in rats after oral PA administration. The derived ARfD value is further supported by several case reports describing acute human poisoning following accidental PA intake. The here derived ARfD value may be used for PA risk assessment in cases where the short-term toxicity of PA is of interest in addition to the assessment of the long-term risks.

Pyrrolizidine Alkaloid Extraction and Analysis: Recent Updates

Pyrrolizidine alkaloids are natural secondary metabolites that are mainly produced in plants, bacteria, and fungi as a part of an organism's defense machinery. These compounds constitute the largest class of alkaloids and are produced in nearly 3% of flowering plants, most of which belong to the Asteraceae and Boraginaceae families. Chemically, pyrrolizidine alkaloids are esters of the amino alcohol necine (which consists of two fused five-membered rings including a nitrogen atom) and one or more units of necic acids. Pyrrolizidine alkaloids are toxic to humans and mammals; thus, the ability to detect these alkaloids in food and nutrients is a matter of food security. The latest advances in the extraction and analysis of this class of alkaloids are summarized in this review, with special emphasis on chromatographic-based analysis and determinations in food.

Seasonal Variability in Pyrrolizidine Alkaloids in Jacobaea alpina from the Trentino-Alto Adige Region (Northern Italy)

In recent years, increased attention has been given to plants containing toxic pyrrolizidine alkaloids (PAs). Jacobaea alpina (syn. Senecio cordatus) is a tall forb growing on mountain pastures and meadows containing such alkaloids and therefore, the plant is considered as a noxious weed in these environments. The repartition of toxic macrocyclic PAs in the plant and their evolution during the vegetation period has been studied in two populations. Eight PAs were found where senciphylline and senecionine accounted in most samples for more than 85 % of total alkaloids. Leaves in April and stems in May started with high PA concentrations (19-22 mg/g dry matter), then alkaloid levels declined. This decrease was more rapid in stems than in leaves. Depending on the population, fully developed inflorescences in June and July PA contents were higher or lower than in the respective leaves. Later, also in the inflorescences PA concentration decreased. Combined with growth data total alkaloid content in the whole plant as mg/plant was highest in midsummer and declined afterwards. Finally, new emerging leaves in September had high PA levels, which declined markedly towards the end of the season in November. In sum, over a large period PA concentration appeared to be high enough to present a health risk for grazing animals.

Rumen Metabolism of Senecio Pyrrolizidine Alkaloids May Explain Why Cattle Tolerate Higher Doses Than Monogastric Species

Rumen metabolism of Senecio pyrrolizidine alkaloids (PAs) and their N-oxide forms was studied by mass spectrometry in in vitro batch culture incubates and confirmed in in vivo samples. Most N-oxides were found to undergo rapid conversion to their corresponding free bases, followed by biotransformation to metabolites hydrogenated at both the necine base and the necic acid moiety. Therefore, rumen metabolism can be considered a detoxification step, as saturated necine base structures are known as the platyphylline type, which is regarded as less or nontoxic. Individual Senecio PAs, such as jacoline, are metabolized slowly during rumen fermentation. PAs that showed limited biotransformation in the rumen in this study also showed limited transformation and CYP-mediated bioactivation in the liver in other studies. This could not only explain why PAs that are comparatively metabolically stable can pass into milk but also suggest that such PAs might be considered compounds of lesser concern.

MicroRNAs as serum biomarker for Senecio brasiliensis poisoning in cattle

Senecio spp. is one of the most frequent plant-related poisonings in cattle. Its ingestion generates the disease seneciosis, characterized by hepatic damages. Liver biopsies and serum markers dosage are tools used in diagnosis; however, many breeding cattle are undiagnosed. MicroRNAs are non-coding RNA, stable in biological fluids. Their difference in expression levels may indicate the presence of the poisoning. We analyzed the miRNA profiling to identify potential diagnostic biomarkers for Senecio brasiliensis poisoning. The expression of miR-21, miR-885, miR-122, miR-181b, miR-30a, miR-378, and let-7 f were evaluated in the serum of exposed cattle. At least one histological change was found in liver and lower quantity of albumin and high AST and ALP were also detected. MiRNAs miR-30a, miR-378, miR-21, miR-885, and miR-122 presented significantly higher expression in intoxicated animals than in healthy animals. Furthermore, miR-122, miR-885, and, especially, miR-21 signatures demonstrated high sensitivity and specificity, with potential application for detecting poisoning.

Effects of ensiling conditions on pyrrolizidine alkaloid degradation in silages mixed with two different Senecio spp

Pyrrolizidine alkaloid (PA) producing plants like Senecio jacobaea or Senecio vernalis are undesirable in fields for forage production, since PA are toxic to animals and humans. Previous studies have shown that ensiling can decrease the PA content in forages; however, no direct comparison of diverse PA from different Senecio spp. under various ensiling conditions has been made. Therefore, it was hypothesised that individual PA might react differently to ensiling, and silage inoculation with Lactobacillus will affect PA degradation because of a quick drop in pH, contrastingly to poor silage qualities resulting from contamination with soil. Laboratory scale grass silages were prepared in a multifactorial design with two levels of dry matter contents, four ensiling treatments and two storage durations (10 and 90 d). For each combination, four replicates were prepared individually. Ensiling treatments were (1) 10 ml water per kg fresh matter as control (CON), (2) 10 ml heterofermentative Lactobacillus buchneri strain LN4637 at 3 · 10⁵ cfu/kg fresh matter plus 25 g molasses/kg fresh matter (LBHE), (3) 10 ml homofermentative lactobacilli at 3 · 10⁵ cfu/kg fresh matter plus 25 g molasses/kg fresh matter (LBHO) and (4) 10 g soil/kg fresh matter (SOIL). Treatments affected formation of fermentation acids. Acetic acid was highest with treatment LBHE, and butyric acid was highest with treatment SOIL. All ensiling treatments effectively reduced total PA content by degrading the PA N-oxide (PANO) fraction. In parallel, though, the fraction of the tertiary base forms increased by around one-tenth of the original PANO content. Contents of jaconine and senkirkine were higher after ensiling than before, with regards to the sum of PA and PANO for jaconine, indicating higher stability or new formation through degradation of other PA. Overall, ensiling offers opportunities to decrease the PA-PANO content in feed and therefore lowers the risk of intoxication by Senecio in livestock.

S. M. Montenegro MC, Rodríguez-Díaz JM. Contaminants in the cow's milk we consume? Pasteurization and other technologies in the elimination of contaminants

Cow's milk is currently the most consumed product worldwide. However, due to various direct and indirect contamination sources, different chemical and microbiological contaminants have been found in cow's milk. This review details the main contaminants found in cow's milk, referring to the sources of contamination and their impact on human health. A comparative approach highlights the poor efficacy and effects of the pasteurization process with other methods used in the treatment of cow's milk. Despite pasteurization and related techniques being the most widely applied to date, they have not demonstrated efficacy in eliminating contaminants. New technologies have appeared as alternative treatments to pasteurization. However, in addition to causing physicochemical changes in the raw material, their efficacy is not total in eliminating chemical contaminants, suggesting the need for new research to find a solution that contributes to improving food safety.

Effects of the herbal preparation AyuFertin, used for anestrus overcome, on fatty acids composition of milk in Bulgarian Murrah buffaloes

The herbal protocols, used instead of hormones in buffalo breeding for reproduction optimisation, do not provide information of their effect on the milk quality of treated animals. This research analysed whether the herbal preparation AyuFertin (Indian Herbs Specialities Pvt. Ltd, Saharanpur), applied in postpartum period for recovering the ovary cycling, had a side effect on the milk composition. The experiment was conducted with buffaloes of the Bulgarian Murrah breed at average age of 50 months during May-June 2019, divided into control (n=6) and experimental (n=7) groups. The experimental buffaloes received AyuFertin orally for three consecutive days at a dose of 3 g/100 kg live weight since the 21st postpartum day. The animals without signs of estrus were treated again after 10 days. The milk samples were collected at test-days, before and after treatments. The fatty acid composition of the milk and Ayufertin was evaluated by gas chromatography-mass spectrometry analysis. Quantification of the identified fatty acids in milk was made by the area normalisation method. In general, the fatty acids composition did not differ after the treatment with AyuFertin. Deviation in the amounts of some fatty acids was established. The content of medium-chain fatty acids such as lauric and capric was decreased, while the amount of long-chain acids such as 11-hexadecanoic and stearic was increased in the experimental group. The main active components of AyuFertin - trienoic acids were not transferred into the milk of treated animals. In conclusion, due to the ability of AyuFertin to affect the fatty acids amount in the milk of treated buffaloes, farmers should strictly follow the manufacturer’s recommendation for the dose and duration of AyuFertin treatment to avoid negative effects on milk quality.

Determination of pyrrolizidine alkaloids in tea and honey with automated SPE clean-up and ultra-performance liquid chromatography/tandem mass spectrometry

For routine analytical purpose a method based on a combination of automated solid-phase extraction (SPE) clean-up and detection by Ultra-Performance Liquid Chromatography/Tandem Mass Spectrometry (UPLC-MS/MS) was developed for the determination of pyrrolizidine alkaloids (PA) in various food commodities. In this survey, honey, tea and herbal infusion samples from local retailers collected in 2012-2015 were obtained and analysed for their PA content. PA concentrations were found in 30% of the honey samples and in 42% of the tea and herbal infusion samples with levels up to 595 µg/kg. The survey included 17 individual PA, and their sum is also reported for each sample.

Targeted LC-MS/MS combined with multilocus DNA metabarcoding as a combinatory approach to determine the amount and the source of pyrrolizidine alkaloids contamination in popular cooking herbs, seeds, spices and leafy vegetables

Pyrrolizidine alkaloids (PAs) and their corresponding N-oxides (PANOs) are natural protoxins biosynthesised by many plant species and are responsible for occasional fatal intoxication outbreaks due to the consumption of contaminated food. However, only in rare cases has the origin of the contamination been determined. Although their presence has been studied in many matrices, occurrence data on popular widely used cooking herbs, seeds, spices and leafy vegetables is very scarce. Therefore, a systematic study on the occurrence of PA/PANOs contaminations in these popular herbal items, available on the Belgian market, was performed, by means of a validatedtargeted LC-MS/MS analysis, followed by multilocus DNA metabarcoding to track back the origin of the contamination for seven highly to moderately contaminated samples. Our results clearly indicate that 21% of the seed spices and 25% seed-based aromatic mixes contain an amount higher than 400 μg of the 30 summed targeted PAs and PANOs per kg, the value which is currently under discussion by the European member states to be set as a maximum threshold. For both the herbs and the herb-based mixes only 7% of analysed samples exceeded these levels. As a proof of concept, multilocus DNA metabarcoding was performed on six highly contaminated samples, belonging to each subtype matrix, containing high levels of heliotrine type of PA/PANOs. Each time the analysis demonstrated the presence of DNA from a plant species belonging to the plant genus Heliotropium. Moreover, a contaminated leafy vegetable sample, containing solely senecionine type PA/PANOs, contained DNA from Senecio vulgaris. Taken together, it can be stated that the proposed combinatory chemical and molecular techniques could be used to verify if a PA/PANO(s) contamination occurred in these popular cooking items and to pinpoint the origin the contamination, which is pivotal in the case of a detrimental intoxication or intoxication outbreak.

Fluorescent lateral flow immunoassay based on gold nanocluster for detection of pyrrolizidine alkaloids

An ultrasensitive and rapid fluorescent immunoassay based on a broad-spectrum monoclonal antibody (mAb) was developed to detect pyrrolizidine alkaloids (PAs) in honey samples. First, Discovery Studio software was used to analyze and predict the target hapten, and retrorsine (RTS) was selected to react with succinic anhydride (HS) for hapten synthesization. A sensitive and broad-spectrum monoclonal antibody (mAb 13E1) was obtained for nine PAs. Then, fluorescent gold nanoclusters (AuNCs) were conjugated with mAb as a label probe and used in establishing a qualitative and quantitative lateral flow immunoassay (AuNCs-LFIA) for the determination of four PAs (retrorsine, platyphylline, senecionine, integerrimine) in honey within 14 min. The limits of detection (LOD) were 0.083 μg/kg. The recovery in spiked honey samples were 87.98-119.57%, with coefficients of variation of ≤ 11.5%. A total of 45 commercial import honey samples from nine different countries were tested through AuNCs-LFIA and UPLC-MS/MS method, and satisfactory consistency (R2 = 0.995) was obtained. The rates of positive samples were 55.56% (25/45), and the average concentrations of four PAs were 3.24-46.47 μg/kg. This ultrasensitive multi-PA method provides an alternative analytical tool for evaluating the human risk posed by the consumption of PA-contaminated honey.

The invasive butterbur contaminates stream and seepage water in groundwater wells with toxic pyrrolizidine alkaloids

Pyrrolizidine alkaloids (PAs) are persistent mutagenic and carcinogenic compounds produced by many common plant species. Health authorities recommend minimising human exposure via food and medicinal products to ensure consumer health and safety. However, there is little awareness that PAs can contaminate water resources. Therefore, no regulations exist to limit PAs in drinking water. This study measured a PA base concentration of ~ 70 ng/L in stream water adjacent to an invasive PA-producing plant Petasites hybridus (Asteraceae). After intense rain the PA concentration increased tenfold. In addition, PAs measured up to 230 ng/L in seepage water from groundwater wells. The dominant PAs in both water types corresponded to the most abundant PAs in the plants (senkirkine, senecionine, senecionine N-oxide). The study presents the first discovery of persistent plant toxins in well water and their associated risks. In addition, it for the first time reports monocrotaline and monocrotaline N-oxide in Petasites sp.

Transfer of pyrrolizidine alkaloids from ragwort, common groundsel and viper's bugloss to milk from dairy cows

To investigate the transfer of pyrrolizidine alkaloids (PAs) from feed to milk, rumen-cannulated dairy cows were intra-ruminally fed with 200 g/day of dried plant material of either ragwort (mixture of Jacobaea vulgaris and Senecio inaequidens), common groundsel (Senecio vulgaris) or viper's bugloss (Echium vulgare) for a period of 4 days. PA levels in the plant materials were 3767, 2792 and 1674 µg g^-1 respectively. Feed intake, milk yield and several blood parameters indicative for liver function were not influenced by the treatment. When fed ragwort, increased levels of PAs were detected in the milk, in particular jacoline and an unidentified cyclic diester, possibly a hydroxylated metabolite from retrorsine. The latter was the most important PA in milk from cows fed common groundsel. For viper's bugloss, echimidine was the most abundant identified PA but in addition several hydroxylated PA metabolites were detected. For ragwort, the overall PA transfer was estimated at 0.05% and 1.4% for jacoline (N-oxide). Transfer rates were similar for viper's bugloss (0.05%) but lower for common groundsel (0.01%). Only a small portion of the administered PAs was quantified in milk, urine and faeces, with an overall balance of 4.5%, 2.9% and 5.8%, for ragwort, common groundsel and viper's bugloss, respectively. Samples taken from the rumen indicated that the N-oxides were converted into the free bases, which was confirmed by in vitro studies with the same plant species incubated with ruminal fluid. These results confirm that the transfer of PAs to milk is relatively low but may be of concern for human health regarding the genotoxic and carcinogenic properties of these compounds. The transfer rate depends on the type of PAs present in the weeds. The incomplete balance of input vs output stresses the need to further investigate the metabolism and the potential transfer of metabolites into edible products.

Rapid identification and determination of pyrrolizidine alkaloids in herbal and food samples via direct analysis in real-time mass spectrometry

Pyrrolizidine alkaloids (PAs) are naturally occurring plant toxins associated with severe liver damage if excessive ingestion. Herein, a novel analytical strategy on utilizing direct analysis in real-time mass spectrometry (DART-MS) was developed, and applied in analysis of six representative PAs. The calibration curves in the range of 10-1000 ng·mL^-1 were established, and relative standard deviations (RSDs) were less than 10%. The limits of detection (LODs) and limits of quantitation (LOQs) were 0.55-0.85 ng·mL^-1 and 1.83-2.82 ng·mL^-1, respectively. The feasibility of method was indicated by analysing real samples including Gynura japonica, drug tablets, granules, and fresh cow's milk. Moreover, the results of DART-MS were in good agreement with those observed by high performance liquid chromatography mass spectrometry (HPLC-MS), but consumed less time without chromatographic separation. This research provides a facile fashion for safety assessment of herbal and food products containing PAs and presents promising applications in food, pharmaceutical and clinical analysis.

Stability of pyrrolizidine alkaloids from Senecio vernalis in grass silage under different ensilage conditions

BACKGROUND

This study evaluated the degradation of pyrrolizidine alkaloids (PAs) from eastern groundsel (Senecio vernalis) in grass silage prepared with different inoculants. Silages were produced from ryegrass with 230 g kg^-1 dry matter (DM) content and mixed with eastern groundsel (9:1; w/w fresh matter basis) containing 5.5 g kg^-1 DM PA. Treatments were: CON (untreated control), LP (3.0 × 10⁵  cfu g^-1 Lactobacillus plantarum DSMZ 8862/8866) or LBLC (7.3 × 10⁴  cfu g^-1 Lactobacillus buchneri LN40177 / Lactobacillus casei LC32909), and each of the treatments in combination with 30 g kg^-1 molasses. Silages were prepared in glass jars and opened after 3, 10, and 90 days. Fermentation characteristics were determined and the PAs analyzed.

RESULTS

Although the levels of fermentation acids differed between treatments, results indicated good quality of all silages during 90 days. Significant time (P < 0.001) and treatment (P < 0.001) effects were observed for PAs. Concentrations of senecionine and seneciphylline decreased with molasses, declined over time, and were negatively correlated with lactic, propionic, and butyric acid, or with lactic and butyric acid in case of seneciphylline. In all silages, seneciphylline and senecionine N-oxides were undetectable after 3 days, whereas senkirkine, the most abundant PA, remained stable.

CONCLUSIONS

Silage prepared from grass contaminated with eastern groundsel still contained high PA levels, and was hence a potential health hazard. Molasses supplementation reduced concentrations of senecionine and seneciphylline, while the bacterial inoculants had no effect. Other potentially toxic PA metabolites were not analyzed in the present study and further research is needed. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evaluation of Cytotoxicity and Mould Contamination of Selected Plants from Meadows Covered by the Agri-Environmental Program

The aim of the study was the evaluation of selected species of meadow plants obtained from the first cut from the area covered by the agri-environmental program 'Natura 2000' in terms of the presence of cytotoxic compounds detected by the MTT test and the level of fungal contamination. The research was carried out on plant species that were evaluated differently in previously used methods for quality assessment of pasture feeds according to Klapp and Filipek. Twenty-six plant species were harvested in 2014 from meadows located in the valley of the Bydgoszcz Canal. Mycological examination of meadow plant samples was carried out according to PN-ISO 7954:1999. Cytotoxicity evaluation was performed using the MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test. Selected samples were also subjected to evaluation of the endophytes occurrence in grasses using PCR. Natural meadow positions included in the study were dominated by moulds belonging to Humicola spp., Alternaria spp., Cladosporium spp., Torula spp., Fusarium spp. and Mucor spp. The highest level of fungal contamination was observed for Carex acutiformis Ehrh. The most infested grasses were Deschampsia caespitosa (L.) P.Beauv., Festuca arundinacea Schreb. and Lolium perenne L. The MTT test showed that the most cytotoxic species were Arrhenatherum elatius (L.) P.Beauv. (IC50 1.563 mg/mL) and Ranunculus repens L. (IC50 3.125 mg/mL). Epichloë endophytes were detected in one of 13 examined grass samples. Our own research suggests that previously used feed quality assessments should be verified by introducing modern methods of molecular biology and instrumental analysis. Results of this study may broaden the knowledge of the causes of problems resulting from feeding of roughage, mainly from natural meadows, and help in creating new rankings of the feed value of meadow sward components.

New glutathione conjugate of pyrrolizidine alkaloids produced by human cytosolic enzyme-dependent reactions in vitro

RATIONALE

The toxic metabolites of pyrrolizidine alkaloids (PAs) are initially formed by cytochrome P450-mediated oxidation reactions and primarily eliminated as glutathione (GSH) conjugates. Although the reaction between the reactive metabolites and GSH can occur spontaneously, the role of the cytosolic enzymes in the process has not been studied.

METHODS

The toxic metabolites of selected PAs (retrorsine, monocrotaline, senecionine, lasiocarpine, heliotrine or senkirkine) were generated by incubating them in 100 mM phosphate buffer (pH 7.4) containing liver microsomes of human, pig, rat or sheep, NADPH and reduced GSH in the absence or presence of human, pig, rat or sheep liver cytosolic fraction. The supernatants were analyzed using liquid chromatography connected to Finnigan LTQ ion-trap, Agilent QTOF or Thermo Scientific Q Exactive Focus quadrupole-orbitrap mass spectrometers.

RESULTS

Retrorsine, senecionine and lasiocarpine yielded three GSH conjugates producing [M - H]^- ions at m/z 439 (7-GSH-DHP (CHO)), m/z 441 (7-GSH-DHP (OH)) and m/z 730 (7,9-diGSH-DHP) in the presence of human liver cytosolic fraction. 7-GSH-DHP (CHO) was a novel metabolite. Monocrotaline, heliotrine and senkirkine did not produce this novel 7-GSH-DHP (CHO) conjugate. 7-GSH-DHP (CHO) disappeared when incubated with hydroxylamine, and a new oxime derivative was formed. This metabolite was formed only by the human liver cytosolic enzymes but not in the presence of rat or sheep liver cytosolic fractions under otherwise identical reaction conditions.

CONCLUSIONS

7-GSH-DHP (CHO) has not been reported before, and thus it was considered as a novel metabolite of PAs. This may clarify the mechanisms involved in PA detoxification and widely observed but less understood species differences in response to PA exposure.

Use of a New LC-MS Method for The Determination of Pyrrolizidine Alkaloids in Feeds

INTRODUCTION

Pyrrolizidine alkaloids (PAs) are secondary metabolites produced by many plant species. Due to their toxicity PAs can pose a risk to human and animal health. To detect the toxic compounds in feed materials a sensitive method based on liquid chromatography coupled with mass spectrometry has been developed.

MATERIAL AND METHODS

PAs were extracted with sulphuric acid and purified with cation exchange cartridges. A newly developed solvent mixture consisting of ethyl acetate, methanol, acetonitrile, ammonia, and triethylamine was used to wash alkaloids from the cartridges. After evaporation the residues were reconstituted in water and methanol mixture and subjected to LC-MS analysis.

RESULTS

The developed method was validated according to SANTE/11945/2015 guidelines. The recovery was from 84.1% to 112.9%, the repeatability ranged from 3.0% to 13.6%, and the reproducibility was from 4.8% to 18.9%.

CONCLUSIONS

A sensitive and selective method for determination of PAs in feed materials has been developed and validated. All evaluated validation parameters were in accordance with EU Reference Laboratories document no. SANTE/11945/2015. Almost 41% of the analysed feed samples were positive for the presence of at least one PA.

Influence of Storage on the Stability of Toxic Pyrrolizidine Alkaloids and Their N-Oxides in Peppermint Tea, Hay, and Honey

1,2-Dehydropyrrolizidine alkaloids (PA) and PA- N-oxides (PANO) are phytotoxins, which presumably occur in more than 6,000 plant species worldwide. Plants containing PA/PANO are responsible for various food and feed poisonings recorded for decades. Main reasons of exposition of consumers and livestock are contaminations of food and animal feed with parts, seeds, pollen, or nectar of PA-containing plants. Concerning stability, effects of processing on PA were mainly investigated in the past. The current study examined the behavior of PA/PANO in unprocessed matrices peppermint tea, hay, and honey during storage. Blank samples were fortified with PA/PANO or contaminated with blueweed ( Echium vulgare) and ragwort ( Senecio jacobaea) and stored for 182 d. The time-series analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) confirmed that all 25 analyzed PA/PANO compounds remained stable in herbal samples. However, the results showed a very fast decrease of PANO in honey samples within hours. These results were discussed with respect to potential consequences for health risk assessment.

Development of an Analytical Method for Analyzing Pyrrolizidine Alkaloids in Different Groups of Food by UPLC-MS/MS

Suspected nontargeted pyrrolizidine alkaloids (PAs), without analytical reference standard, were observed and interfered with the determination of targeted PAs in complex food matrices, especially for spices samples. Selectivity and applicability of multiple reaction monitoring (MRM) transitions, multistage fragmentation (MS3), and MRM with differential ion mobility spectrometry (DMS) for eliminating false positive identifications were evaluated. Afterward, a selective and sensitive LC-MS/MS method for the determination of 15 PAs and 13 PA N-oxides in foodstuffs was developed. The sample preparation and cleanup are applicable to a wide range of foodstuffs, including cereal products, dairy products, meat, eggs, honey, tea infusion, and spices. Freezing-out of the raw extract and the water/acetonitrile washing steps in a solid phase extraction was found to efficiently remove complex matrices. The method was validated at 0.05 μg kg^-1 for general food and 0.5 μg kg^-1 for spices, with reference to the Eurachem Guide. The estimated limit of quantifications of different PAs was in the range of 0.010-0.087 μg kg^-1 for general food and 0.04-0.76 μg kg^-1 for spices. Isotopically labeled PAs were used as internal standards to correct the variation of PAs/PANs performance in different food commodities. Matrix effects observed in complex food matrices could be reduced by solvent dilution. Recoveries of PAs and PA N-oxides were all seen within 50-120%.

Influence of grass pellet production on pyrrolizidine alkaloids occurring in Senecio aquaticus-infested grassland

1,2-Dehydro-pyrrolizidine alkaloids (PA) and their N-oxides (PANO) exhibit acute and chronic toxic effects on the liver and other organs and therefore are a hazard for animal and human health. In certain regions of Germany, an increasing spread of Senecio spp. (ragwort) on grassland and farmland areas has been observed during the last years leading to a PA/PANO-contamination of feed and food of animal and plant origin. This project was carried out to elucidate whether the process of grass pellet production applying hot air drying influences the content of PA and PANO. Samples of hay (n = 22) and grass pellets (n = 28) originated from naturally infested grassland (around 10% and 30% dominance of Senecio aquaticus) and from a trial plot with around 50% dominance. Grass pellets were prepared from grass originating from exactly the same plots as the hay samples. The samples were analysed by liquid chromatography-tandem mass spectrometry for PA/PANO typically produced by this weed. The results of the study revealed that PA/PANO levels (predominantly sum of senecionine, seneciphylline, erucifoline and their N-oxides) in hay ranged between 2.1 and 12.6 mg kg^-1 dry matter in samples with 10% and 30% dominance of S. aquaticus, respectively. Samples from the trial plot (50% dominance) had levels of up to 52.9 mg kg^-1. Notably, the hot air drying process during the production of grass pellets did not lead to a reduction of PA/PANO levels. Instead, the levels in grass pellets with 10% and 30% S. aquaticus ranged from 3.1 to 55.1 mg kg^-1. Grass pellets from the trial plot contained up to 96.8 mg kg^-1. In conclusion, hot air drying and grass pellet production did not affect PA/PANO contents in plant material and therefore, heat-dried products cannot be regarded as safe in view of the toxic potential of 1,2-dehydro-pyrrolizidine alkaloids.

Occurrence of pyrrolizidine alkaloids in animal- and plant-derived food: results of a survey across Europe

Pyrrolizidine alkaloids (PAs) are secondary metabolites of plant families such as Asteraceae or Boraginaceae and are suspected to be genotoxic carcinogens. Recent investigations revealed their frequent occurrence in honey and particularly in tea. To obtain a comprehensive overview of the PA content in animal- and plant-derived food from the European market, and to provide a basis for future risk analysis, a total of 1105 samples were collected in 2014 and 2015. These comprised milk and milk products, eggs, meat and meat products, (herbal) teas, and (herbal) food supplements collected in supermarkets, retail shops, and via the internet. PAs were detected in a large proportion of plant-derived foods: 91% of the (herbal) teas and 60% of the food supplements contained at least one individual PA. All types of (herbal) teas investigated were found to contain PAs, with a mean concentration of 460 µg kg^-1 dry tea (corresponding to 6.13 µg L^-1 in [herbal] tea infusion). The highest mean concentrations were found in rooibos tea (599 µg kg^-1 dry tea, 7.99 µg L^-1 tea infusion) and the lowest in camomile tea (274 µg kg^-1 dry tea, 3.65 µg L^-1 tea infusion). Occurrence of PAs in food supplements was found to be highly variable, but in comparable ranges as for (herbal) tea. The highest concentrations were present in supplements containing plant material from known PA-producing plants. In contrast, only 2% of the animal-derived products, in particular 6% of milk samples and 1% of egg samples, contained PAs. Determined levels in milk were relatively low, ranged between 0.05 and 0.17 µg L^-1 and only trace amounts of 0.10-0.12 µg kg^-1 were found in eggs. No PAs were detected in the other animal-derived products.

Fate of pyrrolizidine alkaloids during processing of milk of cows treated with ragwort

To investigate the fate of pyrrolizidine alkaloids (PAs) during milk processing, milk of cows treated via rumen fistula with a mixture of 84% (w/w) ragwort (Jacobaea vulgaris, syn. Senecio jacobaea) and 16% narrow-leaved ragwort (Senecio inaequidens) was processed using laboratory scale heating systems with industrial settings. Pasteurised and sterilised (UHT) milk were produced, as well as set-type yoghurt and cheese. Samples were analysed for 29 PAs using LC-MS/MS, of which 11 PAs were detected above LOQ in the samples (0.1 µg l^-1). Alterations in the PA concentration and composition between the standardised milk and the corresponding end-product(s) were evaluated. The heat treatments applied for pasteurisation and UHT sterilisation to prepare semi-skimmed consumption milk did not affect the PA levels in the end-products. In yoghurt, after fermentation of standardised milk (6 h, pH 4.4), 73% of total PAs were recovered. The PA concentration, specifically dehydrojacoline, was decreased, although not quantifiable, during cheese production. A further decrease of 38% during 6 weeks of ripening was observed. The results show that the PA concentration of natural contaminated cow's milk is not affected by heat treatment applied for pasteurised and sterilised milk, but that microbial fermentation of the milk leads to a lowered PA concentration in yoghurt and cheese. This is probably due to microbiological degradation, since PAs are fairly stable under acidic conditions.

Multiple heart-cutting two dimensional liquid chromatography quadrupole time-of-flight mass spectrometry of pyrrolizidine alkaloids

Pyrrolizidine alkaloids (PAs) and their and the corresponding N-oxides (PAs-ox) are genotoxic plant metabolites which can be present as unwanted contaminants in food products of herbal origin like tea and food supplements. PAs and PAs-ox come in a wide variety of molecular structures including many structural isomers. For toxicity assessment it is important to determine the composition of a sample and to resolve all isomeric PAs and PAs-ox, which is currently not possible in one liquid or gas chromatographic (LC or GC) run. In this study an online two dimensional liquid chromatography quadrupole time-of-flight mass spectrometry (2D-LC QToF-MS) method was developed to resolve isomeric PAs and PAs-ox. After comprehensive column and mobile phase selection a polar endcapped C₁₈ column was used at pH 3 in the first dimension, and a cross-linked C₁₈ column at pH 10 in the second dimension. Injection solvents, column IDs, flow rates and temperatures were carefully optimized. The method with column selection valve switching described in this study was able to resolve and visualize 20 individual PAs/PAs-ox (6 sets of isomers) in one 2D-LC QToF-MS run. Moreover, it was shown that all isomeric PAs/PAs-ox could be unambiguously annotated. The method was shown to be applicable for the determination and quantification of isomeric PAs/PAs-ox in plant extracts and could be easily extended to include other PAs and PAs-ox.

Determination of pyrrolizidine alkaloids in selected feed materials with gas chromatography-mass spectrometry

1,2-Dehydropyrrolizidine alkaloids are known to be toxic to many animals and humans. To provide safety of feeds a method based on gas chromatography-mass spectrometry enabling the determination of a content of 1,2-unsaturated PAs in feed materials was developed. After extraction with aqueous solution of HCl and purification of the extract, 1,2-unsaturated alkaloids are reduced to their common backbone structures and subsequently derivatised with heptafluorobutyric anhydride (HFBA). The method was validated according to SANTE/11945/2015. All received parameters are consistent with the document requirements as recovery of a final compound retronecine derivative was from 81.8% to 94.4% when retrosine was used for spiking and from 72.7% to 85.5% when retrorsine N-oxide was spiked. The repeatability was calculated as relative standards deviation and ranged from 7.5% to 14.4%, for N-oxide was from 7.9% to 15.4%. The reproducibility was in the range from 14.2% to 16.3% and from 17.0% to 18.1% for free base and N-oxide respectively. The limit of quantification was determined as 10 µg kg^-1. Good linearity of the method was obtained with coefficient of determination R² > 0.99. The method was applied to 35 silage and two hay samples analysis.

Hepatic Lipodystrophy in Galloway Calves

Hepatic lipodystrophy in Galloway calves is a fatal liver disease affecting a small proportion of the Galloway breed described in different parts of Europe and North America during the past decades. The clinical findings include a diversity of neurological signs. Clinical pathology findings frequently indicate hepatobiliary disease. Postmortem examination reveals an enlarged, pale yellow, and firm liver. Histologic lesions include hepatic fibrosis, hepatic lipidosis, and bile duct hyperplasia. To date, the etiopathogenesis remains obscure. Infectious causes, intoxications, and a hereditary origin have been considered. We describe hepatic lipodystrophy in Galloway calves from an extensively farmed cow-calf operation in southern Germany. Main clinical findings in 6 calves were consistent with hepatic encephalopathy. Clinical pathology findings in 5 of 6 tested animals revealed increased concentration of total bilirubin (maximum value [MV], 54 μmol/l; reference range [RR], <8.5 μmol/l), direct bilirubin (MV, 20 μmol/l; RR, <3.4 μmol/l), increased activity of gamma glutamyl transferase (MV, 162 U/l; RR, <36 U/l) and glutamate dehydrogenase (MV, 420 U/l; RR, <16 U/l). In addition, activity of glutathione peroxidase was decreased in all tested ( n = 5) animals (MV, 61 U/g hemoglobin [Hb]; RR, >250 U/g Hb). Postmortem examination in 6 calves revealed a firm, diffusely enlarged yellow liver with a finely nodular surface. Histologic lesions included hepatic fibrosis, hepatic lipidosis, and bile duct hyperplasia. Our findings add to the existing data on hepatic lipodystrophy in the Galloway breed and outline a protocol to aid in the diagnosis of this disorder.