Hypoglycin A in Cow’s Milk—A Pilot Study

Abstract

Hypoglycin A (HGA) originating from soapberry fruits (litchi, and ackee) seeds or seedlings from the sycamore maple (SM) tree (related to Sapindaceae) may cause Jamaican vomiting sickness in humans and atypical myopathy in horses and ruminants. A possible transfer into dairy cow’s milk cannot be ruled out since the literature has revealed HGA in the milk of mares and in the offal of captured deer following HGA intoxication. From a study, carried out for another purpose, bulk raw milk samples from four randomly selected dairy farms were available. The cows were pastured in the daytime. A sycamore maple tree was found on the pasture of farm No. 1 only. Bulk milk from the individual tank or milk filling station was sampled in parallels and analyzed for HGA by LC-ESI-MS/MS. Measurable concentrations of HGA occurred only in milk from farm No. 1 and amounted to 120 and 489 nmol/L. Despite low and very variable HGA concentrations, the results indicate that the ingested toxin, once eaten, is transferred into the milk. However, it is unknown how much HGA the individual cow ingested during grazing and what amount was transferred into the bulk milk samples. As a prerequisite for a possible future safety assessment, carry-over studies are needed. Furthermore, the toxins’ stability during milk processing should also be investigated as well.

A sensitive LC–MS/MS method for the quantification of the plant toxins hypoglycin A and methylenecyclopropylglycine and their metabolites in cow’s milk and urine and application to farm milk samples from Germany

“…The LOD and LOQ for HGA, MCPrG, MCPA-glycine, MCPF-glycine, and MCPA-carnitine in milk and urine are summarized in Table 2 and Table 3 , respectively. The LOQ presented here for HGA in milk (1.12 µg/L) is noticeably lower than the limit of detection reported by Bochnia et al (9 µg/L) [ 29 ]. In urine, the LOQ for MCPA-glycine and MCPF-glycine of the proposed method were 78.9 and 41.6 µg/L, respectively, which are lower than the lowest limit reported in human urine by Isenberg et al (100 µg/L) [ 36 ].…”

“…Maple trees are especially abundant in central Europe and the USA, which may pose a risk of animal intoxication following ingestion of maple seeds and seedlings. Previous reports have indicated that these toxins could pass into the milk of mare [ 27 , 28 ] and cows [ 29 ], consequently predisposing humans to a health risk if contaminated milk is ingested.…”

“…In addition, HGA, MCPA-glycine, MCPA-carnitine, MCPF-glycine, and MCPF-carnitine have been detected in some commercial horse milk samples [ 28 ]. HGA excretion in milk of other species has been also demonstrated by the detection of HGA in nursing lambs’ [ 34 ] and cow’s milk [ 29 ]. The evaluation of possible health risks to humans calls for reliable data on the presence and levels of HGA and MCPrG in milk.…”

“…Several LC–MS/MS methods for the quantification of HGA, MCPrG and their glycine and carnitine metabolites in urine and milk have been reported. The majority of these methods involved pre-column derivatization with butanol (3N HCl in n -butanol) [ 22 , 28 , 35 ] or fluorenylmethoxycarbonyl (Fmoc) [ 29 ]. Few methods have demonstrated the LC–MS quantification without derivatization [ 36 ].…”

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

“…The rumen chyme is less liquid and the ventral groove less developed which both limit the rumen bypass [ 30 , 48 ]. It has to be noted that HGA has been detected in cow’s milk [ 49 ]. In those cows, some HGA must have gotten through the rumen, which leads to the hypothesis that, under a high toxic pressure, even these grazers might be at risk of HGA poisoning.…”