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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 12.6mg 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 52.9mg 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 55.1mg kg(-1). Grass pellets from the trial plot contained up to 96.8mg 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.

Pyrrolizidine alkaloids (PAs) are a class of naturally occurring compounds produced by many flowering plants around the World. Their presence as contaminants in food systems has become a significant concern in recent years. For example, PAs are often found as contaminants in honey through pollen transfer. A validated method was developed for the quantification of four pyrrolizidine alkaloids and one pyrrolizidine alkaloid N-oxide in plants and honey grown and produced in British Columbia. The method was optimised for extraction efficiency from the plant materials and then subjected to a single-laboratory validation to assess repeatability, accuracy, selectivity, LOD, LOQ and method linearity. The PA content in plants ranged from1.0 to 307.8 µg/g with repeatability precision between 3.8 and 20.8% RSD. HorRat values were within acceptable limits and ranged from 0.62 to 1.63 for plant material and 0.56-1.82 for honey samples. Method accuracy was determined through spike studies with recoveries ranging from 84.6 to 108.2% from the raw material negative control and from 82.1-106.0 % for the pyrrolizidine alkaloids in corn syrup. Based on the findings in this single-laboratory validation, this method is suitable for the quantitation of lycopsamine, senecionine, senecionine N-oxide, heliosupine and echimidine in common comfrey (Symphytum officinale), tansy ragwort (Senecio jacobaea), blueweed (Echium vulgare) and hound's tongue (Cynoglossum officinale) and for PA quantitation in honey and found that PA contaminants were present at low levels in BC honey.

Senecio inaequidens is a neophyte originating from South Africa that has managed to spread to Europe and colonize large areas. This plant has toxic pyrrolizidine alkaloids (PAs) that represent a health risk to humans and animals. The aim of this work was to measure the content of PAs of these plants in continuous intervals over the entire growing season. The plants were separated into their organs, such as sprouts, stems, leaves and inflorescences. PAs were extracted from the dried plants using an acidic methanol solution, purified and measured by GC/MS. The average PA content of plants over the growing season was 0.33% of dry weight. The highest PA levels were about 1% in the dry weight and were found in the young sprouts and flower heads. There were nine PAs present, of which six could be identified. The main alkaloid was retrorsine followed by senecivernine, senecionine, integerrimine, usaramine and seneciphylline. Due to the high PA content of the inflorescences, the long flowering period and the rapi...

The present investigation is a comparative study which evaluate the antimicrobial activity of the Senecio leucanthemifolius poiret essential oil from a side and the hexanic, dichlormethanic and methanolic extracts from the other side. The GC-MS analysis affirms that the plant contains α-hydroxy-p-cymen (27.3 %), carvacrol (12.2 %), nerol (10.9 %) carveol (9.2 %) and cis-α-bisabolene (7.0 %). Moreover, the analysis showed the presence of two pyrrolizindes alkaloids which are Senecionine, Integerrimine (7.2 %) and two quinonoides which are 1-amino-1-ortho- chlorophenyl-2-(2-quinoxalinyl) ethene (4.1 %) and 6-ethyl-5-hydroxy-2,3,7-trimethoxynaphthoquinone (3.3 %). The antimicrobial effect was evaluated using the diffusion technique on solid media by measuring in (mm) the zones of growth inhibition. The essential oil showed a considerable antimicrobial activity against two Escherichia coli (E.coli) genetically modified strains MG and TG1, Rhizobium RP8 and Bacillus subtilis. However, the hexanic, dich...

Senecio grisebachii Baker is an invasive weed considered to be toxic due to the presence of pyrrolizidine alkaloids (PA) in its tissues. The PA production by S. grisebachii aerial parts was evaluated in samples grown in two Argentinean Rolling Pampa fields with the same kind of soil but differing in the length of their exploitation period by conventional tillage practices and, consequently, in their deterioration level. We found significant differences in the relative concentrations of seven alkaloids between samples taken from the two fields. Seneciphylline was the most abundant alkaloid in inflorescences from less deteriorated soil (LD) while senecionine was the major one in those from highly deteriorated soil (D) being followed by seneciphylline, integerrimine, and minor amounts of spartiodine, jacobine, jacozine and retrorsine. A significant increase in total alkaloid content (TAC) was observed in inflorescences from samples growing in D soil (3.52±0.20 mg/g DW) when comparing with those from...

A rapid reversed-phase high-performance liquid chromatographic (RP-HPLC) method was established for simultaneous determination of senecionine, senlciphylline, and senecionine N-oxide in a famous traditional Chinese medicine, Gynura segetum, which has been commonly used for hemostasis. The HPLC assay was performed on a Kromasil KR100-5 C18 column (25 cm × 4.6 mm, 5 µm) with mobile phase composed of acetonitrile and 0.2% phosphoric acid–triethylamine within 40 min. The detection wavelength was 220 nm. All the compounds showed good linearity (r2 > 0.9997). The method was reproducible with intra- and interday variation less than 2.82%. The recovery of the assay was in the range of 96.55–103.88%. The method was successfully applied to the quantification of three constituents in 15 Gynura segetum samples collected from different metropolis. The results indicated that the developed assay could be considered as a suitable quality-control method for Gynura segetum.

SUMMARY The toxic pyrrolizidine alkaloids (PAs) senecionine and integerrimine are minor compounds in the rhizomes of the medicinal plant Petasites hybridus. Plants used in phytopharmacy should be as low in PAs as possible. The present work investigates whether the PA content of the rhizomes can be lowered in the progenies obtained from selected plants through experimental crossings. Starting from plants differing in the PA content, two consecutive crossing generations (F1 and F2) were established. The PAs were recorded in the young runners of the rhizome. The results showed that various progenies differed clearly in their PA content and even within a progeny the PA content may vary considerably. Plants poor in alkaloids generally generate offspring lower in PA than parent plants with a high alkaloid level. However plants totally free of alkaloids could not be generated through the crossing experiments.

A method was developed for the determination in honey of the Ragwort (Senecio jacobaea) derived pyrrolizidine alkaloids jacoline, jacozine, jacobine, seneciphylline and senecionine, combining solid-phase extraction with high performance liquid chromatography and atmospheric pressure chemical ionization mass spectrometric detection. The method allowed determination of individual alkaloids and offered a considerable improvement in terms of speed, sensitivity and specificity over previous approaches, but was not suitable for determination of jaconine, a minor alkaloid in Ragwort. Instrument calibrations were linear over the range 0.005 to 100 micrograms/ml, equivalent to approximately 0.001 to 2.0 mg/kg in honey with the extraction method used and allowing for observed recoveries. Detection limits in honey were 0.002 mg/kg. Recoveries for most of the alkaloids were between 57 and 70%. The alkaloids have been determined in a number of samples of honey selected after pollen identification and counting. The alkaloids were not detectable in samples containing two grains or less of Ragwort pollen per gram of honey. Samples collected in late July and August contained Ragwort pollen at 15-21 grains/g and total alkaloid concentrations of 0.011-0.056 mg/kg. Similar contributions to the total were made by jacozine, seneciophylline and senecionine, with jacobine making a larger and jacoline a smaller contribution. Two samples of honey containing Ragwort pollen at 24 and 16 grains/g had total alkaloid concentrations of 0.42 and 1.48 mg/kg respectively (not corrected for recovery). The alkaloid profile in these samples was dominated by seneciphylline and senecionine which together comprised 90-95% of the total. Alkaloids were not detected in retail honeys.

1. We have purified three P450s from the liver of the phenobarbital (PB)-treated guinea pig in order to evaluate the role of these enzymes in pyrrolizidine alkaloid (PA) metabolism. 2. PB treatment of guinea pig increased the hepatic microsomal conversion of the PA senecionine (SN) to the pyrrolic metabolite (+/-)6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP), an activation product, and SN N-oxide, a detoxification product by 224 and 70% respectively. 3. Reconstitution of a PB-inducible guinea pig P4502B isoform (M(r) = 57,512 by MALDI-TOF mass spectrometry) in a reconstituted system metabolized SN to DHP and SN N-oxide at rates of 1.98 and 1.45 min-1 respectively. A second purified guinea pig P450, a 2C-type isoform (M(r) = 56,496 by MALDI-TOF mass spectrometry), produced SN N-oxide from SN at the rate of 13.3 min-1 but catalyzed little DHP formation. The third guinea pig P450, an apparent 3A type (M(r) = 54-56,000 by SDS-PAGE), lost its catalytic activity towards SN during the final purification process. 4. Immunoinhibition of microsomal SN metabolism by rabbit antibodies raised against the guinea pig P4502B, 2C and 3A isoforms indicated that the 2B played the most important role (70% of the total metabolism) in bioactivation of SN in both the untreated or PB-treated guinea pig, whereas 2C and 3A seemed to exhibit little (around 13%) PA metabolism. P4502B, along with flavin-containing monooxygenase, also contributed to the detoxification of SN in both the untreated (34%) and PB-treated (40%) guinea pig. 5. This study suggests that the putative P4502B form plays the most important role in SN bioactivation in guinea pig.

A Phytochemical Investigation Of The Overground Parts Of Sencio Glabellus Resulted In Isolation and Identification Of Five Pyrrolizidine Alkaloids: Florosenine (Acetylotosenine), Senecionine, Integerrimine, Otosenine and Senkirkine, By Comparison With Authentic Samples. Separation Of The First Three Of These Alkaloids From Otosenine and Senkirkine Was Realized By A Simple Liquid/Liquid Extraction Procedure Which Is Reported. This Is The First Report Of The Occurrence Of Florosenine, Otosenine and Senkirkine In S. Glabellus.

This paper studies the formation and extraction of ion pairs of some alkaloids derived from pyrrolizidine. The substances studied are Nemorensine, Platyphylline, Senecionine and Seneciphylline, and the ion pairs studied and extracted are formed with Bil4. The method consists of extracting an ion pair between the organic base and the inorganic complex, the metal is measured in the organic phase (1,2 dichloroethane) by Flame AAS. The optimal experimental conditions, pH, concentration of BiI4 −, shaking time, phase ratio, number of extractions, and the range of calibration are studied for these substances. The linear range in organic phase is 0.13–1.91 mg.mL−1. The standard deviation of the method varies between 2.4–3.2%, depending on the substance analyzed. The interferences produced by various substances are studied.

The influences of in vivo pretreatment with phenobarbitone (PB), 3-methylcholanthrene (3-MC), 2,2',4,4',5,5'-hexachlorobiphenyl (HCBP), and 3,3',4,4'-tetrachlorobiphenyl (TCBP) on cytocidal hepatotoxicity of two pyrrolizidine alkaloids, lasiocarpine (LC) and senecionine (SC), were compared in short-term primary cultures of rat hepatocytes. Toxicity was measured by release of lactate dehydrogenase (LDH) into culture medium at 24 h. LC was slightly more toxic to control hepatocytes than SC in the graded response range of 10-160 microM. PB and HCBP (a PB-type polychlorobiphenyl inducer) similarly potentiated toxicity of SC, and each diminished the degree to which cell killing by LC and SC was inhibited by SKF-525-A. By comparison, 3-MC and TCBP (a 3-MC-type PCB inducer) each diminished toxicity of SC but had little effect on toxicity of LC. Alpha-naphthoflavone (ANF) potentiated toxicity of both LC and SC in hepatocytes induced by 3-MC or TCBP but had little effect on responses of hepatocytes induced by either PB or HDBP. These results indicate that xenobiotics that induce similar patterns of cytochrome P-450 isozymes have qualitatively similar modulating influences on cytocidal hepatotoxicity of pyrrolizidine alkaloids in primary cultures. However, the observed modulating effects could not be explained solely on the basis of altered activation rates by the cytochrome P-450 species known to be induced by the various xenobiotics.