Pyrrolizidine Alkaloids Concentration Research Articles

Pyrrolizidine Alkaloids in Tea (Camellia sinensis L.) from Weeds through Weed-Soil-Tea Transfer and Risk Assessment of Tea Intake.

Pyrrolizidine alkaloids (PAs) have been detected in tea and can threaten human health. However, the specific source of PAs in tea is still unclear. Here, 88 dried tea products collected from six major tea-producing areas in Anhui Province, China, were analyzed. The detection frequency was 76%. The content of total PAs in dried tea was between 1.1 and 90.5 μg/kg, which was all below the MRL recommended by the European Union (150 μg/kg). In the Shexian tea garden, PAs in the weeds and weed rhizospheric soil around tea plants and the fresh tea leaves were analyzed. Intermedine (Im), intermedine-N-oxide (ImNO), and jacobine-N-oxide (JbNO) were transferred through the weed-to-soil-to-tea route into the fresh tea leaves; only Im and ImNO were detected in dried tea samples. Potential risk of the total PAs in the tea infusion was assessed according to the margin of exposure method, and it might be a low concern for public health.

PSI-17 Use of Sunn Hemp as Forage for Early-Weaned Beef Calves

Abstract Sunn hemp (Crotalaria juncea) has been widely used as cover crop in the USA and due to superior biomass accumulation and nutritive value, there is interest from producers to use sunn hemp as forage for livestock. However, sunn hemp has pyrrolizidine alkaloids, which can affect animal performance. The objective of this study was to evaluate the effects of feeding sunn hemp hay to early-weaned beef calves in a dry lot in Florida. The experiment was conducted at the UF/IFAS Range Cattle Research and Education Center, Ona, FL from April to May 2021 (42 d). Treatments were calves receiving sunn hemp or stargrass (Cynodon nlemfuensis) hay distributed in a randomized complete block design with 12 replicates. Calves were supplemented with concentrate at 1.3% BW daily (18% CP and 78% TDN). Twenty-four Angus crossbred calves were weaned with 90 ± 14 kg BW and grazed annual ryegrass (Lolium multiflorum) with 1% BW concentrate supplementation for approximately 60 d. Subsequently, calves were randomly distributed and assigned to experimental units (pen) on 14 April 2021 with initial BW of 184 ± 10 kg. ‘Ubon’ sunn hemp hay was harvested approximately 49 d after seeding when 75% of the plants were initially flowering. Ground hay was fed daily targeting 10% refusals, and the initial CP and in vitro digestible organic matter concentrations of sunn hemp and stargrass hay were 9 and 48%, and 9 and 47%, respectively. The average concentration of pyrrolizidine alkaloids from sunn hemp hay was 58 μg/g DM. Early-weaned calves receiving stargrass had a tendency to have greater ADG than sunn hemp (0.5 vs. 0.4 kg/d, P = 0.09), and had greater forage DM intake (1.2 vs. 1.0% BW, P < 0.01) and total DM intake (2.5 vs. 2.3% BW, P < 0.01). Conversely, diets with sunn hemp had greater in vivo DM digestibility than stargrass (68 vs. 62%, P = 0.04). There was no difference between treatments on parasite egg count (mean = 45 eggs/3 g feces, P = 0.25) and coccidia egg count (log10 eggs/g feces, P = 0.35). Early-weaned calves receiving sunn hemp consumed 0.25 g pyrrolizidine alkaloids/d; however, there was no detectable amount (< 0.05 μg/g DM) of pyrrolizidine alkaloids in the feces. The presence of pyrrolizidine alkaloids in sunn hemp may be the potential cause of decreased early-weaned calves forage intake and animal performance.

Evaluation of the thermal stability and transfer rate of pyrrolizidine alkaloids during the brewing of herbal infusions contaminated with Echium vulgare and Senecio vulgaris weeds

Pyrrolizidine alkaloids (PAs) are currently in the spotlight of food safety due to the potential health risk that their intake may entail for consumers. Among the wide variety of food products likely to be contaminated with PAs, teas and herbal teas stand out because of their cross-contamination with weeds from PA-producing plants. Accordingly, this work simulates the cross-contamination of chamomile tea samples with weeds of Senecio vulgaris and Echium vulgare to evaluate the effect of brewing on the PA content at different temperature (100 and 75 °C) and time (5 and 10 min) conditions. The results of the thermal degradation study revealed PAs are quite stable compounds under the conditions assayed, being the initial PA concentration the variable that strongly affected the thermal stability of these compounds, rather than the brewing temperature and time. On the other hand, it was confirmed that not all PAs are effectively transferred from the dry material to the infusion during the brewing process, leading to overall transfer rates between 13 ± 1 to 87 ± 10%. Also, it was observed that the extraction efficiency may be influenced by the type of matrix, since transfer rates were lower when the PA migration came from Echium vulgare than from Senecio vulgaris. Moreover, it was confirmed that the real content of PAs in a cup of tea can be overestimated in 2–7 times if their transfer rate is not considered during the brewing process, highlighting the importance of analyzing the infusion samples instead of the dry tea samples to correctly assess the risk exposure of consumers to these contaminants.

LC-MS/MS Evaluation of Pyrrolizidine Alkaloids Profile in Relation to Safety of Comfrey Roots and Leaves from Polish Sources.

Comfrey (Symphytum officinale L.) has a long tradition of use in the treatment of musculoskeletal disorders. However, due to hepatotoxic pyrrolizidine alkaloids (PAs), the EMA restricts the use of comfrey root (CR) to external use only and for short periods of time. Recent studies indicate a low permeability of PAs across the skin, calling into question the safety of topical application of products containing comfrey preparations. The aim of our work was to develop and validate an HPLC method enabling the separation of isomeric PAs from comfrey and, on this basis, to assess the potential toxicity of CR and comfrey leaf (CL) obtained from various Polish sources. The qualitative and quantitative analysis of PAs via HPLC-MS/MS was performed in MRM mode. The results obtained confirmed a lower content of PAs in CL than in CR and showed a wide variation in the composition of PAs in CR, with a much more stable profile of PAs in CL. Factor analysis confirmed that CRs and CLs differ in PA content, which is influenced by the growth conditions and geographical origin. The determined concentrations of PAs prove that in some CRs available on the Polish herbal market, the content of PAs may exceed the daily dose considered safe.

Pyrrolizidine Alkaloids in Food on the Italian Market.

Pyrrolizidine alkaloids (PAs) are secondary metabolites produced by over 6000 plant species worldwide. PAs enter the food chain through accidental co-harvesting of PA-containing weeds and through soil transfer from the living plant to surrounding acceptor plants. In animal studies, 1,2-unsaturated PAs have proven to be genotoxic carcinogens. According to the scientific opinion expressed by the 2017 EFSA, the foods with the highest levels of PA contamination were honey, tea, herbal infusions, and food supplements. Following the EFSA's recommendations, data on the presence of PAs in relevant food were monitored and collected. On 1 July 2022, the Commission Regulation (EU) 2020/2040 came into force, repealed by Commission Regulation (EU) 2023/915, setting maximum levels for the sum of pyrrolizidine alkaloids in certain food. A total of 602 food samples were collected from the Italian market between 2019 and 2022 and were classified as honey, pollen, dried tea, dried herbal infusions, dried herbs, and fresh borage leaves. The food samples were analyzed for their PA content via an in-house LC-MS/MS method that can detect PAs according to Regulation 2023/915. Overall, 42% of the analyzed samples were PA-contaminated, 14% exceeded the EU limits, and the items most frequently contaminated included dried herbs and tea. In conclusion, the number of food items containing considerable amounts of PAs may cause concern because they may contribute to human exposure, especially considering vulnerable populations-most importantly, children and pregnant women.

Occurrence and associated health risks of pyrrolizidine alkaloids in supplements marketed in Ghana for improved sexual performance

ABSTRACT Pyrrolizidine alkaloids (PAs) are noted for their hepatotoxic, genotoxic, and carcinogenic effects in animals and humans following metabolic activation in the liver. In this study, herbal supplements sold in Ghana for sexual improvement were analysed for the presence of 64 PAs using LC-MS/MS analysis. Up to 17 different PAs were identified in 19 out of the 37 samples analysed. The sum of PAs in samples ranged from 5 to 3204 μg kg−1. Since the PA content in the herbal medicinal preparations was generally lower than in honey samples, their presence was mainly attributed to cross-contamination. The observed levels would result in estimated daily intakes from 0.01 to 12 μg per day or 0.0002 to 0.2 μg kg−1 bw day−1 for a person weighing 70 kg. The margins of exposure ranged from 1200 to 1,400,000 with eight samples showing values below 10,000, thus indicating a health concern.

Structural annotation, semi-quantification and toxicity prediction of pyrrolizidine alkaloids from functional food: In silico and molecular networking strategy.

Many traditional Chinese herbs contain pyrrolizidine alkaloids (PAs), which have been reported to be toxic to livestock and humans. However, the lack of PAs standards makes it difficult to effectively conduct a risk assessment in the varied components of traditional Chinese medicine. It is necessary to propose a suitable strategy to obtain the representative occurrence data of PAs in complex systems. A comprehensive approach for annotating the structures, concentration, and mutagenicity of PAs in three Chinese herbs has been proposed in this article. First, feature-based molecular networking (FBMN) combined with network annotation propagation (NAP) on the Global Natural Products Social Molecular Networking web platform speeds up the process of annotating PAs found in Chinese herbs. Second, a semi-quantitative prediction model based on the quantitative structure and ionization intensity relationship (QSIIR) is used to forecast the amounts of PAs in complex substrates. Finally, the T.E.S.T. was used to provide predictions regarding the mutagenicity of annotated PAs. The goal of this study was to develop a strategy for combining the results of several computer models for PA screening to conduct a comprehensive analysis of PAs, which is a crucial step in risk assessment of unknown PAs in traditional Chinese herbal preparations.

Pyrrolizidine alkaloids and health risk of three Boraginaceae used in TCM.

Objective: The aim of this study was to systematically explore the pyrrolizidine alkaloids (PAs) type, content and risk assessment in the three Boraginaceae used in TCM, involving Arnebia euchroma (AE), A. guttata (AG), and Lithospermum erythrorhizon (LE). Method: A UHPLC-MS/MS method was established to simultaneously determine eight pyrrolizidine alkaloids (PAs), namely intermedine, lycopsamine, intermedine N-oxide, lycopsamine N-oxide, 7-acetyllycopsamine, 7-acetyllycopsamine N-oxide, echimidine N-oxide, and echimidine in the three herbs. Based on these results, the risk assessment was explored using the routine margin of exposure (MOE) combined with relative potency (REP) for oral and external usage, respectively. Results and Conclusion: Imermedine and imermedine N-oxide were common components in the eight tested PAs. 7-acetyllycopsamine and its N-oxide were not detected in AE; echimidine and its N-oxide were not detected in AG; lycopsamine and its N-oxide, 7-acetyllycopsamine and its N-oxide were not detected in LE. The total contents of 8 PAs in 11 batches of AG was341.56-519.51 μg/g; the content in 15 batches of LE was 71.16-515.73 μg/g, and the content in 11 batches of AE was 23.35-207.13 μg/g. Based on these results, the risk assessment was explored using MOE combined with REP for oral and external usage, respectively. The findings of the risk assessment method of PAs based on MOE combined with the REP factor were consistent with the clinical toxicity results. As an oral herb, AE had low risk or no risk due to its low PA contents, and individual batches of LE were medium risk, while attention should be paid to their clinical use.AG was also low risk. The external use of the three Boraginaceae used in TCM was not associated with any risk. This study systematically explored the PA type and content of the three Boraginaceae used in TCM. Additionally, the refined risk assessment of PAs based on REP provided a more scientific basis for quality evaluation and rational use of the medicinal Boraginaceae used in TCM to improve public health.

Physiologically based kinetic modeling of senecionine N-oxide in rats as a new approach methodology to define the effects of dose and endpoint used on relative potency values of pyrrolizidine alkaloid N-oxides.

Over 1,000 pyrrolizidine alkaloids (PAs) and their N-oxides (PA-N-oxides) occur in 3% of all flowering plants. PA-N-oxides are toxic when reduced to their parent PAs, which are bioactivated into pyrrole intermediates that generate protein- and DNA-adducts resulting in liver toxicity and carcinogenicity. Literature data for senecionine N-oxide in rats indicate that the relative potency (REP) value of this PA-N-oxide compared to its parent PA senecionine varies with the endpoint used. The first endpoint was the ratio between the area under the concentration-time curve (AUC) for senecionine upon dosing senecionine N-oxide or an equimolar dose of senecionine, while the second endpoint was the ratio between the amount for pyrrole-protein adducts formed under these conditions. This study aimed to investigate the mode of action underlying this endpoint dependent REP value for senecionine N-oxide with physiologically based kinetic (PBK) modeling. Results obtained reveal that limitation of 7-GS-DHP adduct formation due to GSH depletion, resulting in increased pyrrole-protein adduct formation, occurs more likely upon high dose oral PA administration than upon an equimolar dose of PA-N-oxide. At high dose levels, this results in a lower REP value when based on pyrrole-protein adduct levels than when based on PA concentrations. At low dose levels, the difference no longer exists. Altogether, the results of the study show how the REP value for senecionine N-oxide depends on dose and endpoint used, and that PBK modeling provides a way to characterize REP values for PA-N-oxides at realistic low dietary exposure levels, thus reducing the need for animal experiments.

Do Fungicides Affect Alkaloid Production in Catharanthus roseus (L.) G. Don. Seedlings?

The presence of endophytes in plants is undeniable, but how significant their involvement is in the host plant biosynthetic pathways is still unclear. The results reported from fungicide treatments in plants varied. Fungicide treatment in Taxus was found to decrease the taxol content. In Ipomoea asarifolia, Pronto Plus and Folicur treatments coincided with the disappearance of ergot alkaloids from the plant. In Narcissus pseudonarcissus cv. Carlton, a mixture of fungicide applications decreased the alkaloids concentration and altered the carbohydrate metabolism. Jacobaea plants treated with Folicur reduced the pyrrolizidine alkaloids content. There have not been any studies into the involvement of endophytic fungi on alkaloids production of Catharanthus roseus until now. Though there is a report on the isolation of the endophytic fungi, Fusarium oxysporum from C. roseus, which was reported to produce vinblastine and vincristine in vitro. To detect possible collaborations between these two different organisms, fungicides were applied to suppress the endophytic fungi in seedlings and then measure the metabolomes by 1HNMR and HPLC analysis. The results indicate that endophytic fungi were not directly involved in alkaloids biosynthesis. Treatment with fungicides influenced both the primary and secondary metabolism of C. roseus. The systemic fungicides Pronto Plus and Folicur caused an increase in loganin and secologanin levels. In contrast, control samples had higher level of catharanthine and vindoline. This means that fungicide treatments cause changes in plant secondary metabolism.

Hemolytic crisis in 8-year-old known case of glucose 6 phosphate dehydrogenase deficiency secondary to Heliotropium curassavicum ingestion: a case report

Background: The genus Heliotropium encompasses plants that exhibit a variety of pharmacological properties. Even though this plant has many therapeutic uses, some portions of salt heliotrope contain high concentrations of pyrrolizidine alkaloids (PA), which have been extremely hazardous substances that can seriously impair the liver of both humans and animals. Human poisoning cases are extremely uncommon. Symptoms of poisoning, which often include hemolytic jaundice, photosensitization, and eventually death. Case Presentation: An 8-year-old boy, with a known case of autism and glucose-6-phosphate dehydrogenase (G6PD) deficiency, presented to our institute complaining of vomiting and diarrhea after ingestion of a part of a leaf in the farm (Heliotropium Curassavicum); blood workup was ordered and it showed hemolytic anemia crisis and was managed by hydration and blood transfusion. Conclusion: This case adds to the literature by documenting an acute hemolytic anemia crisis due to the ingestion of H. curassavicum in an 8-year-old child who has been diagnosed with G6PD deficiency.

Profiling of pyrrolizidine alkaloids using a retronecine-based untargeted metabolomics approach coupled to the quantitation of the retronecine-core in medicinal plants using UHPLC-QTOF

Pyrrolizidine alkaloids (PA) are secondary metabolites of high toxicological relevance. Several PA quantitative methodologies were developed based on a limited number of certified standards, including time consuming solid phase extraction (SPE) purification steps. Herein, we shed light on the variability of PA in herbal extracts and propose a quantification methodology based on ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS) for the evaluation of the total PA content as retronecine-equivalents (RE) directly from crude matrices. Particularly in the focus of the investigation were Alkanna spp. (Boraginaceae), which possess a wide range of pharmaceutical properties. In addition, a comparative PA screening of crude and SPE enriched extracts was performed and PA-containing plants from Fabaceae and Compositae families were included to demonstrate universal applicability. In total, 105 PA were identified using HRMSe experiments, specific MS/MS fragmentation PA patterns, a customized in-house library and literature data. Among them, 18 glycosidic PA derivatives were reported for the first time in literature. Using a hierarchical clustering approach, PA distribution in herbal extracts was shown to be family-dependent and significantly different among species. This was further supported by the results of the total PA concentrations, obtained using a retronecine/heliotridine/internal standard-based targeted UHPLC-HRMS quantification method, which varied from 8.64 ± 0.08–3096.28 ± 273.72 μg RE/g extract dry weight in shoots extracts of Alkanna spp. and leaves extracts of Crotalaria retusa L. respectively. Worth mentioning is that the procedure allowed to quantify PA in Alkanna spp. If the procedure based on 35 specific PA recommended by European regulations had been used, results would have been equal to zero for the four species since none were observed in Alkanna spp. Finally, by combining the RE results with the corresponding dereplication results, a customized correction factor for each extract (ranging from 2.12 to 2.48) was assessed leading to a more accurate estimate of the PA content regardless of the molecular weight of each PA. The present methodology will facilitate PA quantification directly from crude extracts and avoid the underestimation the real PA content due to limited availabilty of authentic reference compounds in botanical extracts used in phytomedicines or food supplements/cosmetics.

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.

Development and Validation of an UHPLC-MS/MS Method for the Determination of 32 Pyrrolizidine Alkaloids in Chinese Wild Honey.

Studies on pyrrolizidine alkaloid (PA) contamination in honey produced in China are scarce. Previously reported HPLC-MS/MS methods for the determination of PAs in honey often suffer from insufficient separation and uncertainties in PA isomers. To develop and validate an Ultra-HPLC (UHPLC)-MS/MS method for baseline separation of PA isomers towards precise determination of 32 PAs in Chinese wild honey. PAs were extracted from honey samples and separated on an ACQUITY BEH C18 (2.1 mm × 100 mm, 1.7 µm) column with (A) 0.1% formic acid aqueous solution containing 5 mM ammonium acetate and (B) methanol as mobile phase. The column temperature was maintained at 30°C, and flow rate was 0.3 mL/min. Detection was performed by tandem mass spectrometry. The total run time was reduced to 18 min. Thirty-one of 32 PAs were baseline separated efficiently within 18 min. The LOD and LOQ were 0.06-0.25 µg/kg and 0.22-0.82 µg/kg, respectively, except for that of clivorine, for which LOD and LOQ were 2.03 and 6.78 µg/kg, respectively. The average recoveries ranged between 66.3 and 95.1% and the average RSDs were 3.2 to 8%. The established method was used to analyze PAs in 22 types of Chinese wild honey, and the predominant PAs found in these honey samples were intermedine and lycopsamine. A high-throughput method for the determination of isomeric PAs in honey was developed and validated. Five of the 22 types of Chinese wild honey were contaminated with PAs concentrations of 2.2-207.0 µg/kg. A new method capable of monitoring more PAs and providing better separation than previously reported protocols for the determination of multiclass PAs in honey is established.

Effect of Adulteration on Quality and Preliminary Risk Assessment of the Decoction Pieces of Farfarae Flos Based on the Determination of Hepatotoxic Pyrrolizidine Alkaloids by UHPLC-MS/MS.

Farfarae Flos (FF) is a frequently used traditional herbal medicine with outstanding antitussive actions. The adulteration of FF decoction pieces is common. This study aimed to study the effect of adulteration on the safety and quality of FF decoction pieces. The proportion of impurities was conducted by cone quartering method. A simple and accurate ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was established to simultaneous determinate three pyrrolizidine alkaloids (PAs) as endogenous toxic compounds in FF. The traditional medicinal parts (flower bud), impurities (pedicel and rhizome) and unselected samples were determined respectively. The values of estimated daily intake (EDI) and margin of exposure (MOE) were used for risk assessment. Twenty batches of samples were collected from different habitats, and the proportion of impurities ranged from 17.51% to 41.27%. Pedicel and rhizome were the main impurities, accounting for more than 87.40% of the total impurities. The content of PAs in impurities was significantly higher. The EDI value range was 5.34 to 16.59 μg/kg bw/day, which was much higher than the standard safety value of 7.00 × 10-3 μg/kg bw/day. The MOE values ranges for life long time and shorter exposure were 14.29 to 44.37 and 371.53 to 1153.63, respectively, indicating that at least 80% of the samples had safety risks. Correlation analysis showed that the proportion of adulterated impurities had significant correlation with the values of EDI and MOE. Adulteration of non medicinal parts may significantly increase the risk of medications of FF decoction pieces. This study provides an efficient methodology reference for the control of PAs and a basis for adulteration to affect the safety and quality of FF decoction pieces.

Discrimination of Zicao Samples Based on DNA Barcoding and HPTLC Fingerprints, and Identification of (22E)-Ergosta-4,6,8(14),22-tetraen-3-one As a Marker Compound.

The unambiguous identification of plant material is a prerequisite of rational phytotherapy. Misidentification can even cause serious health problems, as in the case of the Chinese medicinal herb Zicao. Commercial material labelled "Zicao" may be derived from the roots of Arnebia euchroma (ruan zicao), Lithospermum erythrorhizon (ying zicao), or Onosma paniculata (dian zicao). All of these roots contain shikonin derivatives as main bioactive constituents, but ying zicao and dian zicao contain also hepatotoxic pyrrolizidine alkaloids in high amounts. Therefore, the use of A.euchroma with a very low pyrrolizidine alkaloid content is desirable. Confusions of the species occur quite often, indicating an urgent need for an unambiguous identification method. Discrimination of 23zicao samples has been achieved by analyses of the nuclear internal transcribed spacer ITS2 and trnL-F intergenic spacer of the chloroplast DNA. Data were analyzed using Bioedit, ClustalX, Mega 11 and BLAST. Results indicate that ITS2 barcoding can accurately distinguish Arnebia euchroma from their adulterants. Subsequently, an HPTLC method has been developed allowing a chemical discrimination of the most widely used species. (22E)-Ergosta-4,6,8(14),22-tetraen-3-one has been identified as characteristic marker compound, allowing an unambiguous discrimination of A.euchroma and L.erythrorhizon.

Variety and Seeding Time Influence on Flowering Characteristics and Trichodesmine Content in Sunn Hemp (Crotalaria juncea L.)

Background: Sunn hemp (Crotalaria juncea L.) is an important annual legume used as green manure. It contains pyrrolizidine alkaloids, which are apparently effective in suppressing nematodes. It is pertinent to know the growth stage during which pyrrolizidine alkaloid concentrations become higher. Methods: The period of days necessary for flowering, pod growth and the concentrations of one pyrrolizidine alkaloid in pods at different stages in five sunn hemp cultivars with May and July seeding were investigated. Result: Findings indicated that flowering of the two cultivars occurred later than the others, especially for May seeding. The pods grew to 20 mm length in 6-11 days from flowering. Then the pods grew to maximum size (40 mm length) in only few days. A main pyrrolizidine alkaloid in sunn hemp seed, trichodesmine, increases as pod size grow; then it increases considerably as pod mature. However, it in matured pod hull contains similar values of whole immature pod. These results demonstrate that both day-neutral and short-day cultivars with July seeding shorten the days to first flower and indicate that cutting after 10 days from first flowering is effective for increasing pyrrolizidine alkaloid concentration.

Utilization of Biomasses from Landscape Conservation Growths Dominated by Common Ragwort (Jacobaea vulgaris Gaertn.) for Biomethanization.

The highly toxic species common ragwort (Jacobaea vulgaris Gaertn.) prefers to migrate into protected dry grassland biotopes and limits the use of the resulting biomass as animal feed. There is an urgent need for a safe alternative use of the contaminated biomass apart from landfill disposal. We investigated the optional utilization of biomethanization of fresh and ensiled common ragwort biomasses and evaluated their energetic potentials by estimation models based on biochemical characteristics and by standardized batch experiments. The fresh and ensiled substrates yielded 174 LN∙kg−1 oDM methane and 185 LN∙kg−1 oDM, respectively. Ensiling reduced the toxic pyrrolizidine alkaloid content by 76.6%; a subsequent wet fermentation for an additional reduction is recommended. In comparison with other biomasses from landscape cultivation, ragwort biomass can be ensiled readily but has a limited energy potential if harvested at its peak flowering stage. Considering these properties and limitations, the energetic utilization is a promising option for a sustainable handling of Senecio-contaminated biomasses in landscape conservation practice and represents a safe alternative for reducing pyrrolizidine alkaloid entry into the agri-food sector.

High abundance of pyrrolizidine alkaloids in bee pollen collected in July 2019 from Southern Germany

Pyrrolizidine alkaloids (PA) are secondary plant defense compounds and known pre-toxins when containing a 1,2-double bond. They are commonly produced by various plants and may thus be present in bee pollen which may be consumed by humans as food supplements. In this study, PA were determined in bee pollen samples from 57 locations in Southern Germany sampled by means of pollen traps in July 2019. Samples were analyzed by using palynological methodology and solid-phase extraction (SPE) followed by LC–MS/MS. In total, 52 pollen samples featured total pyrrolizidine alkaloids (ΣPA) with concentrations up to 48,000 ng/g bee pollen, while the N-oxides (NO) echinatine-NO and rinderine-NO clearly dominated. In contrast, the palynological analysis only detected 33 samples with pollen from PA-producing plants. Accordingly, the results showed that palynological analysis is not sufficient to determine PA in pollen. In addition, a risk assessment was followed to estimate the risk of the detected PA concentrations to humans.

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

ABSTRACT 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.