Detection of MCPG metabolites in horses with atypical myopathy

Atypical myopathy (AM) in horses is caused by ingestion of seeds of the Acer species (Sapindaceae family). Methylenecyclopropylacetyl-CoA (MCPA-CoA), derived from hypoglycin A (HGA), is currently the only active toxin in Acer pseudoplatanus or Acer negundo seeds related to AM outbreaks. However, seeds or arils of various Sapindaceae (e.g., ackee, lychee, mamoncillo, longan fruit) also contain methylenecyclopropylglycine (MCPG), which is a structural analogue of HGA that can cause hypoglycaemic encephalopathy in humans. The active poison formed from MCPG is methylenecyclopropylformyl-CoA (MCPF-CoA). MCPF-CoA and MCPA-CoA strongly inhibit enzymes that participate in β-oxidation and energy production from fat. The aim of our study was to investigate if MCPG is involved in Acer seed poisoning in horses. MCPG, as well as glycine and carnitine conjugates (MCPF-glycine, MCPF-carnitine), were quantified using high-performance liquid chromatography-tandem mass spectrometry of serum and urine from horses that had ingested Acer pseudoplatanus seeds and developed typical AM symptoms. The results were compared to those of healthy control horses. For comparison, HGA and its glycine and carnitine derivatives were also measured. Additionally, to assess the degree of enzyme inhibition of β-oxidation, several acyl glycines and acyl carnitines were included in the analysis. In addition to HGA and the specific toxic metabolites (MCPA-carnitine and MCPA-glycine), MCPG, MCPF-glycine and MCPF-carnitine were detected in the serum and urine of affected horses. Strong inhibition of β-oxidation was demonstrated by elevated concentrations of all acyl glycines and carnitines, but the highest correlations were observed between MCPF-carnitine and isobutyryl-carnitine (r = 0.93) as well as between MCPA- (and MCPF-) glycine and valeryl-glycine with r = 0.96 (and r = 0.87). As shown here, for biochemical analysis of atypical myopathy of horses, it is necessary to take MCPG and the corresponding metabolites into consideration.

[1]  R. Barouki,et al.  Hypoglycemic Toxins and Enteroviruses as Causes of Outbreaks of Acute Encephalitis-Like Syndrome in Children, Bac Giang Province, Northern Vietnam , 2018, Emerging infectious diseases.

[2]  A. Zeyner,et al.  Predictive value of hypoglycin A and methylencyclopropylacetic acid conjugates in a horse with atypical myopathy in comparison to its cograzing partners , 2018 .

[3]  J. Sander,et al.  Quantification of Methylenecyclopropyl Compounds and Acyl Conjugates by UPLC-MS/MS in the Study of the Biochemical Effects of the Ingestion of Canned Ackee (Blighia sapida) and Lychee (Litchi chinensis). , 2017, Journal of agricultural and food chemistry.

[4]  J. Pirkle,et al.  Quantification of Toxins in Soapberry (Sapindaceae) Arils: Hypoglycin A and Methylenecyclopropylglycine. , 2016, Journal of agricultural and food chemistry.

[5]  R. Klopfleisch,et al.  Equine atypical myopathy caused by hypoglycin A intoxication associated with ingestion of sycamore maple tree seeds. , 2016, Equine veterinary journal.

[6]  M. Peter,et al.  Rapid diagnosis of hypoglycin A intoxication in atypical myopathy of horses , 2016, Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

[7]  J. Ziegler,et al.  Hypoglycin A Content in Blood and Urine Discriminates Horses with Atypical Myopathy from Clinically Normal Horses Grazing on the Same Pasture , 2015, PloS one.

[8]  J. Pirkle,et al.  Quantification of metabolites for assessing human exposure to soapberry toxins hypoglycin A and methylenecyclopropylglycine. , 2015, Chemical research in toxicology.

[9]  J. Sejvar,et al.  Outbreaks of Unexplained Neurologic Illness — Muzaffarpur, India, 2013–2014 , 2015, MMWR. Morbidity and mortality weekly report.

[10]  M. Das,et al.  Acute Encephalitis Syndrome in Children in Muzaffarpur: Hypothesis of Toxic Origin , 2014 .

[11]  A. Mouithys-Mickalad,et al.  Identification of methylenecyclopropyl acetic acid in serum of European horses with atypical myopathy. , 2014, Equine veterinary journal.

[12]  K. Martinson,et al.  Seasonal pasture myopathy/atypical myopathy in North America associated with ingestion of hypoglycin A within seeds of the box elder tree. , 2013, Equine veterinary journal.

[13]  J. Paireau,et al.  Litchi–associated Acute Encephalitis in Children, Northern Vietnam, 2004–2009 , 2012, Emerging infectious diseases.

[14]  G. Shelton,et al.  Equine multiple acyl-CoA dehydrogenase deficiency (MADD) associated with seasonal pasture myopathy in the midwestern United States. , 2012, Journal of veterinary internal medicine.

[15]  C. Bowen-Forbes,et al.  Tracking hypoglycins A and B over different maturity stages: implications for detoxification of ackee (Blighia sapida K.D. Koenig) fruits. , 2011, Journal of agricultural and food chemistry.

[16]  D. Barceloux.  Akee fruit and Jamaican vomiting sickness (Blighia sapida Köenig). , 2009, Disease-a-month : DM.

[17]  Ding Li,et al.  Comparative inhibition studies of enoyl-CoA hydratase 1 and enoyl-CoA hydratase 2 in long-chain fatty acid oxidation. , 2008, Organic letters.

[18]  R. Wanders,et al.  Acquired multiple Acyl-CoA dehydrogenase deficiency in 10 horses with atypical myopathy , 2008, Neuromuscular Disorders.

[19]  M. Bennink,et al.  Ackee (Blighia sapida) hypoglycin A toxicity: dose response assessment in laboratory rats. , 2006, Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association.

[20]  L. Backer,et al.  Ackee Fruit Poisoning: An Outbreak Investigation in Haiti 2000–2001, and Review of the Literature , 2006, Clinical toxicology.

[21]  H. Minakata,et al.  Antimutagenic unusual amino acids from plants , 1985, Experientia.

[22]  S. Withers,et al.  A revised mechanism for the inactivation of bovine liver enoyl-CoA hydratase by (methylenecyclopropyl)formyl-CoA based on unexpected results with the C114A mutant. , 2002, Biochemistry.

[23]  S. Dakoji,et al.  Studies on the inactivation of bovine liver enoyl-CoA hydratase by (methylenecyclopropyl)formyl-CoA: elucidation of the inactivation mechanism and identification of cysteine-114 as the entrapped nucleophile. , 2001, Journal of the American Chemical Society.

[24]  Hung‐wen Liu,et al.  The toxicity of methylenecyclopropylglycine: Studies of the inhibitory effects of (methylenecyclopropyl)formyl-CoA on enzymes involved in fatty acid metabolism and the molecular basis of its inactivation of enoyl-CoA hydratases , 1999 .

[25]  J. Cornell,et al.  Influence of fruit maturity on the hypoglycin a level in ackee (Blighia sapida) , 1991 .

[26]  S. Ghisla,et al.  Metabolic consequences of methylenecyclopropylglycine poisoning in rats. , 1991, The Biochemical journal.

[27]  S. Ghisla,et al.  Mechanisms of enzyme inhibition by hypoglycin, methylenecyclopropylglycine and their metabolites. , 1990, Progress in clinical and biological research.

[28]  K. Tanaka,et al.  Hypoglycin and Jamaican vomiting sickness. , 1990, Progress in clinical and biological research.

[29]  S. Ghisla,et al.  Mechanism of hypoglycaemic action of methylenecyclopropylglycine. , 1989, The Biochemical journal.

[30]  H. Sherratt,et al.  The antagonism of the toxicity of hypoglycin by glycine. , 1981, Biochemical pharmacology.

[31]  K. Tanaka,et al.  Jamaican vomiting sickness. Biochemical investigation of two cases. , 1976, The New England journal of medicine.

[32]  L. Fowden,et al.  Cyclopropylamino acids of the genus Acer: Distribution and biosynthesis , 1973 .

[33]  K. Tanaka.  On the mode of action of hypoglycin A. 3. Isolation and identification of cis-4-decene-1,10-dioic, cis, cis-4,7-decadiene-1,10-dioic, cis-4-octene-1,8-dioic, glutaric, and adipic acids, N-(methylenecyclopropyl)acetylglycine, and N-isovalerylglycine from urine of hypoglycin A-treated rats. , 1972, The Journal of biological chemistry.

[34]  von HOLT,et al.  METABOLISM AND METABOLIC EFFECTS OF HYPOGLYCIN. , 1964, Biochimica et biophysica acta.

[35]  L. Fowden,et al.  α-(Methylenecyclopropyl)glycine from Litchi seeds , 1962 .

[36]  L. Fowden,et al.  alpha-(Methylenecyclopropyl)glycine from Litchi seeds. , 1962, The Biochemical journal.

[37]  P. N. Harris,et al.  Pharmacologic action of hypoglycin A and B. , 1957, The Journal of pharmacology and experimental therapeutics.

[38]  C. Hassall,et al.  The toxicity of the ackee (Blighia sapida) and it relationship to the vomiting sickness of Jamaica; a review. , 1955, The West Indian medical journal.

[39]  C. Hassall,et al.  Hypoglycin A,B: Biologically Active Polypeptides from Blighia sapida , 1954, Nature.

[40]  H. Hill.  The Vomiting Sickness of Jamaica. A Review. , 1952 .

[41]  A. Wright.  Vomiting Sickness in Jamaica , 1943, British medical journal.