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Publications (4)38.07 Total impact

  • Article: Giving Samoan healers credit for prostratin.
    Paul Alan Cox, Holly E Johnson, Gaugau Tavana
    Science 07/2008; 320(5883):1589. · 31.20 Impact Factor
  • Article: Cyanobacteria (Nostoc commune) used as a dietary item in the Peruvian highlands produce the neurotoxic amino acid BMAA.
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    ABSTRACT: In the mountains of Peru, globular colonies of Nostoc commune (Nostocales) are collected in the highland lakes by the indigenous people, who call them llullucha. They are consumed locally, traded for maize, or sold, eventually entering the folk markets of Cusco and other neighboring cities. Throughout highland Peru, Nostoc commune is highly salient as a seasonal dietary item, being eaten alone, or in picante -- a local stew -- and is said to be highly nutritious. Nostoc commune has been known to produce unusual amino acids, including those of the mycosporine group, which possibly function to prevent UV damage. We analyzed 21 different Nostoc commune spherical colonies from 7 different market collections in the Cusco area for the presence of beta-N-methylamino-L-alanine (BMAA), a neurotoxic amino acid produced by diverse taxa of cyanobacteria, using four different analytical techniques (HPLC-FD, UPLC-UV, UPLC/MS, LC/MS/MS). We found using all four techniques that BMAA was present in the samples purchased in the Peruvian markets. Since BMAA has been putatively linked to neurodegenerative illness, it would be of interest to know if the occurrence of ALS, Alzheimer's, or Parkinson's Disease is greater among individuals who consume llullucha in Peru.
    Journal of Ethnopharmacology 07/2008; 118(1):159-65. · 3.01 Impact Factor
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    Article: Production of the neurotoxin BMAA by a marine cyanobacterium.
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    ABSTRACT: Diverse species of cyanobacteria have recently been discovered to produce the neurotoxic non-protein amino acid beta-methylamino-L-alanine (BMAA). In Guam, BMAA has been studied as a possible environmental toxin in the diets of indigenous Chamorro people known to have high levels of Amyotrophic Lateral Sclerosis/ Parkinsonism Dementia Complex (ALS/PDC). BMAA has been found to accumulate in brain tissues of patients with progressive neurodegenerative illness in North America. In Guam, BMAA was found to be produced by endosymbiotic cyanobacteria of the genus Nostoc which live in specialized cycad roots. We here report detection of BMAA in laboratory cultures of a free-living marine species of Nostoc. We successfully detected BMAA in this marine species of Nostoc with five different methods: HPLC-FD, UPLC-UV, Amino Acid Analyzer, LC/MS, and Triple Quadrupole LC/MS/MS. This consensus of five different analytical methods unequivocally demonstrates the presence of BMAA in this marine cyanobacterium. Since protein-associated BMAA can accumulate in increasing levels within food chains, it is possible that biomagnification of BMAA could occur in marine ecosystems similar to the biomagnification of BMAA in terrestrial ecosystems. Production of BMAA by marine cyanobacteria may represent another route of human exposure to BMAA. Since BMAA at low concentrations causes the death of motor neurons, low levels of BMAA exposure may trigger motor neuron disease in genetically vulnerable individuals.
    Marine Drugs 02/2007; 5(4):180-96. · 3.85 Impact Factor
  • Article: Searching historical herbal texts for potential new drugs.
    BMJ (Clinical research ed.). 01/2007; 333(7582):1314-5.