Acer pseudoplatanus: A Potential Risk of Poisoning for Several Herbivore Species.

Acer pseudoplatanus is a worldwide-distributed tree which contains toxins, among them hypoglycin A (HGA). This toxin is known to be responsible for poisoning in various species, including humans, equids, Père David's deer and two-humped camels. We hypothesized that any herbivore pasturing with A. pseudoplatanus in their vicinity may be at risk for HGA poisoning. To test this hypothesis, we surveyed the HGA exposure from A. pseudoplatanus in species not yet described as being at risk. Animals in zoological parks were the major focus, as they are at high probability to be exposed to A. pseudoplatanus in enclosures. We also searched for a toxic metabolite of HGA (i.e., methylenecyclopropylacetyl-carnitine; MCPA-carnitine) in blood and an alteration of the acylcarnitines profile in HGA-positive animals to document the potential risk of declaring clinical signs. We describe for the first instance cases of HGA poisoning in Bovidae. Two gnus (Connochaetes taurinus taurinus) exposed to A. pseudoplatanus in their enclosure presented severe clinical signs, serum HGA and MCPA-carnitine and a marked modification of the acylcarnitines profile. In this study, even though all herbivores were exposed to A. pseudoplatanus, proximal fermenters species seemed less susceptible to HGA poisoning. Therefore, a ruminal transformation of HGA is hypothesized. Additionally, we suggest a gradual alteration of the fatty acid metabolism in case of HGA poisoning and thus the existence of subclinical cases.

Analytical documentation of an Arabian horse fatality related to Oenanthe crocata poisoning.

Analytical detection of Oenanthe crocata toxins in biological samples is challenging because of their instability, the lack of commercially available standards and the exceptionally low detection of these molecules using mass spectrometry. This work aims to report the used analytical methods that allowed identification of the main plant toxins in biological samples from an equid (an Arabian horse) fatality related to hemlock water dropwort (Oenanthe crocata Linnaeus) intake. Using both LC-DAD and LC-HRMS methods allowed identification (i) of oenanthotoxin in roots found on the site, root fragments found in the stomach, stomach content, kidney, and liver, and (ii) of the hydrogenated metabolite of oenanthotoxin (2,3-dihydro-oenanthotoxin) in roots found on the site, root fragments found in the stomach, stomach content, kidney, liver and spleen. Reported analytical data about Oenanthe crocata toxins can be useful for identification of the ingested plant and for supporting a poisoning diagnosis in such cases.

Variability of ferulenol and ferprenin concentration in French giant fennel (Ferula sp.) leaves.

Few studies have reported quantitative data about the levels of prenylated coumarins in Ferula sp. Yet, the toxicity of Ferula sp. is only due to the presence of prenylated coumarins and to their concentrations and all studies suggest the existence of several chemotypes within the same species or even within the same variety. The aim of this study was to investigate the hypothesis of different chemotypes in french Ferula sp. in relationship with the botanical species. In this objective, the species of giant fennels and their concentrations in prenylated coumarins were explored. Three different species or subspecies of giant fennel were detected in continental France: F. communis communis communis L., F. communis catalaunica microcarpa Cauwet-Marc and F. glauca L. Surprisingly, the three species/subspecies of giant fennels were found to be located in exclusive and well separated geographical areas. In French giant fennels, ferulenol and ferprenin were detected. Distribution of ferulenol and ferprenin were found to be different between botanical varieties, but also according to the season, the soil and the altitude. Our study seems to suggest that among F. communis species, the same plant can be regarded as poisonous at one point and another as non-poisonous.

Comparative inhibitory effect of prenylated coumarins, ferulenol and ferprenin, contained in the 'poisonous chemotype' of Ferula communis on mammal liver microsomal VKORC1 activity.

Two distinguishable chemotypes of Ferula communis have been described: the 'nonpoisonous' chemotype, containing as main constituents the daucane esters; and the 'poisonous' chemotype containing prenylated coumarins, such as ferulenol and ferprenin. Ferulenol and ferprenin are 4-oxygenated molecules such as dicoumarol and warfarin, the first developed antivitamin K molecules. Antivitamin K molecules specifically inhibit VKORC1, an enzyme essential for recycling vitamin K. This latest is involved in the activation of clotting factors II, VII, IX, X. The inhibiting effect of ferulenol on VKORC1 was shown in rat, but not for species exposed to F. communis while in vivo studies suggest differences between animal susceptibility to ferulenol. The inhibiting effect of ferprenin on VKORC1 was never demonstrated. The aim of this study was to compare the inhibiting effect of both compounds on VKORC1 of different species exposed to F. communis. Vitamin K epoxide activity was evaluated for each species from liver microsomes and inhibiting effect of ferulenol and ferprenin was characterized. Ferulenol and ferprenin were shown to be able to inhibit VKORC1 from all analyzed species. Nevertheless, susceptibility to ferulenol and ferprenin presented differences between species, suggesting a different susceptibility to 'poisonous' chemotypes of F. communis.

Quantification of hypoglycin A in serum using aTRAQ(®) assay.

BACKGROUND: Hypoglycin A has been recently identified has the causal agent of atypical myopathy (AM) in horses. Its identification and quantification in equine's biological fluids is thus a major concern to confirm maple poisoning and to provide insight into the poorly understood mechanism of hypoglycin A intoxication. METHODS: Quantification of hypoglycin A has been achieved with the aTRAQ kit for amino acid analysis of physiological fluids (AB Sciex). Acquisition method on mass spectrometer has been updated to record the hypoglycin A specific MRM transition. RESULTS: Outlined accuracy profiles demonstrated very reliable data. A good linearity was observed from 0.09 to 50µmol/L and precision was very good with coefficient of variation below 8%. Fifty-five samples collected from 25 confirmed AM horses revealed significant hypoglycin A concentrations, while toxin was not found in serum of 8 control animals. CONCLUSIONS: The described aTRAQ variant method has been analytically and clinically validated. The reliability of our approach is thus demonstrated into the workup of atypical myopathy.

A validated method for quantifying hypoglycin A in whole blood by UHPLC-HRMS/MS.

Hypoglycin A (HGA) is the toxic principle in ackee (Blighia sapida Koenig), a nutritious and readily available fruit which is a staple of the Jamaican working-class and rural population. The aril of the unripe fruit has high concentrations of HGA, the cause of Jamaican vomiting sickness, which is very often fatal. HGA is also present in the samara of several species of maple (Acer spp.) which are suspected to cause seasonal pasture myopathy in North America and equine atypical myopathy in Europe, often fatal for horses. The aim of this study was to develop a method for quantifying HGA in blood that would be sensitive enough to provide toxicological evidence of ackee or maple poisoning. Analysis was carried out using solid-phase extraction (HILIC cartridges), dansyl derivatization and UHPLC-HRMS/MS detection. The method was validated in whole blood with a detection limit of 0.35 µg/L (range: 0.8-500 µg/L). This is the first method applicable in forensic toxicology for quantifying HGA in whole blood. HGA was quantified in two serum samples from horses suffering from atypical myopathy. The concentrations were 446.9 and 87.8 µg/L. HGA was also quantified in dried arils of unripe ackee fruit (Suriname) and seeds of sycamore maple (Acer pseudoplatanus L.) (France). The concentrations were 7.2 and 0.74 mg/g respectively.