Biomagnification of cycad neurotoxins in flying foxes

  title={Biomagnification of cycad neurotoxins in flying foxes},
  author={Sandra Anne Banack and Paul Alan Cox},
  pages={387 - 389}
β-Methylamino-l-alanine (BMAA) occurs in higher levels in museum specimens of the Guamanian flying fox than in the cycad seeds the flying foxes feed on, confirming the hypothesis that cycad neurotoxins are biomagnified within the Guam ecosystem. Consumption of a single flying fox may have resulted in an equivalent BMAA dose obtained from eating 174 to 1,014 kg of processed cycad flour. Traditional feasting on flying foxes may be related to the prevalence of neuropathologic disease in Guam. 
Previous studies underestimate BMAA concentrations in cycad flour
  • Ran Cheng, S. Banack
  • Biology, Medicine
    Amyotrophic lateral sclerosis : official publication of the World Federation of Neurology Research Group on Motor Neuron Diseases
  • 2009
Data support a link between ALS/PDC and exposure to BMAA and detected significant levels of protein-associated BMAA in washed cycad flour.
Biomagnification of cyanobacterial neurotoxins and neurodegenerative disease among the Chamorro people of Guam
  • P. Cox, S. Banack, S. Murch
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2003
The biomagnification of BMAA through the Guam ecosystem fits a classic triangle of increasing concentrations of toxic compounds up the food chain, which may explain why the incidence of ALS-PDC among the Chamorro was 50-100 times the occurrence of amyotrophic lateral sclerosis elsewhere.
Distribution of the neurotoxic nonprotein amino acid BMAA in Cycas micronesica
Cycad neurotoxins are concentrated in cycad reproductive organs, with the highest concentrations being found in the immature staminate sporangium and the outmost layer of the sarcotesta, consistent with the putative evolutionary role of BMAA as an antiherbivory compound, as well as the biomagnification of the compound in flying foxes that ingest the seed sarcOTesta.
Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA) in Shark Fins
Consuming shark fins may increase the risk for human exposure to the cyanobacterial neurotoxin BMAA, which has been linked to neurodegenerative diseases and may have important relevance to human health.
The fate of the cyanobacterial toxin β-N-methylamino-L-alanine in freshwater mussels.
Production of the Neurotoxin BMAA by a Marine Cyanobacterium
Diverse species of cyanobacteria have recently been discovered to produce the neurotoxic non-protein amino acid β-methylamino-L-alanine (BMAA). In Guam, BMAA has been studied as a possible
Diatoms: A Novel Source for the Neurotoxin BMAA in Aquatic Environments
It is demonstrated that diatoms – eukaryotic organisms – also produce BMAA, and the use of filter and suspension feeders as livestock fodder dramatically increases the risk of human exposure to BMAA-contaminated food.


Cycad neurotoxins, consumption of flying foxes, and ALS-PDC disease in Guam.
The Chamorro people of Guam have been afflicted with a complex of neurodegenerative diseases with similarities to ALS, AD, and PD at a far higher rate than other populations throughout the world.
Content of the neurotoxins cycasin (methylazoxymethanol β‐D‐glucoside) and BNLAA (β‐N‐methylamino‐L‐alanine) in cycad flour prepared by Guam Chamorros
The cytotoxic properties of cycasin merit consideration in relation to the etiology of western Pacific amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC).
Conservation Implications of Chamorro Consumption of Flying Foxes as a Possible Cause of Amyotrophic Lateral Sclerosis–Parkinsonism Dementia Complex in Guam
Abstract: In the Pacific island of Guam, flying fox (  Pteropus mariannus and P. tokudae ) populations historically persisted for centuries despite subsistence foraging by the indigenous Chamorro
Isolation of various forms of sterol β‐d‐glucoside from the seed of Cycas circinalis: neurotoxicity and implications for ALS‐parkinsonism dementia complex
The hypothesis that cycad consumption may be an important factor in the etiology of ALS‐PDC is supported and the suggestion that some sterol glucosides may be involved in other neurodegenerative disorders is suggested.
Guam amyotrophic lateral sclerosis-parkinsonism-dementia linked to a plant excitant neurotoxin.
The hypothesis that cycad exposure plays an important role in the etiology of the Guam disease is supported, as existing epidemiological and animal data support the hypothesis.
Epidemiologic Investigations of Amyotrophic Lateral Sclerosis
Our observations of the clinical and pathologic characteristics of the neurologic disorder we observed in the Mariana Islands lead us to agree with Arnold and associates’ and with Koerner‘ that this
A cohort study of amyotrophic lateral sclerosis and parkinsonism-dementia on Guam and Rota.
A review of the accumulated epidemiologic data on these neurologic diseases in the Mariana Islands did not support the current hypothesis that a chronic nutritional deficiency of calcium is a cause of both amyotrophic lateral sclerosis and parkinsonism-dementia.
Synthesis of a fluorescent derivatizing reagent, 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, and its application for the analysis of hydrolysate amino acids via high-performance liquid chromatography.
A highly reactive amine derivatizing reagent, 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, has been synthesized in a rapid, one-step procedure to form stable unsymmetric urea derivatives which are readily amenable to analysis by reversed phase HPLC.