June 20, 2012

Monkey-Frog at the Racetrack: Horse dope from the Amazon (Phyllomedusa frog venom)

More than thirty racehorses in Louisiana, Oklahoma, New Mexico and Texas have tested positive for an illegal performance-enhancing drug derived from South American frog venom.  As reported in today’s issue of the New York Times, racing regulators have long suspected that trainers were doping horses with dermorphin, a painkiller forty times more powerful than morphine that is found in skin secretions of the Waxy Monkey Leaf Frog, Phyllomedusa sauvagii, traded internationally as an exotic pet.  Dermorphin belongs to a novel class of compounds first identified in skin secretions of the related frog species Phyllomedusa bicolor, used as a stimulant by indigenous hunters of the Amazon.  Frog venom had so far evaded detection in racehorse drug screening until Denver-based Industrial Laboratories tweaked its tests.

Several Phyllomedusa species have toxic skin secretions

The Spiritain missionary Constantin Tastevin[i] was the first outsider to document the use of frog toxins known locally as kampo by Cashinahua (Kaxinawa) Indians of the upper Juruá River in Brazil.  The Cashinahua collect secretions from the Giant Waxy Monkey Frog (Phyllomedusa bicolor) and administer the substance directly into the bloodstream through small wounds burned with smoldering twigs on the skin.  The treatment produces short-lived bouts of nausea, sweating, vomiting, diarrhea and sometimes unconsciousness, but leaves the user with a lasting sense of strength, well-being and heightened sense perception.  The treatment is especially valued by indigenous hunters for improving their stamina, skill and luck at hunting.  "Hunting magic," as it is sometimes (and perhaps erroneously) called, proves to be an important category of traditional medicine in Amazonia. 

Since Tastevin’s early record, kampo use has been documented by anthropologists among other indigenous groups of the Brazil-Peru border region including the Amahuaca, Yaminahua, Matis, Matses (Mayoruna), Marubo, Katukina and Yawanawa.[ii]  Writer Peter Gorman’s 1993 article in Omni magazine[iii] on Matses "magic" in Peru -- echoing Gordon Wasson's famous 1957 story[iv] on the magic mushrooms of Mexico -- generated  widespread popular interest in the substance.  More recently, indigenous healers from the state of Acre have brought the “frog vaccine” to urban centers throughout Brazil as part of an expansion and popularization of indigenous shamanistic practices.[v]
Indigenous healers administer frog secretions directly into the bloodstream by means of small burns to the skin.

Berkeley anthropologist Katharine Milton first collected scientific samples of Phyllomedusa bicolor secretions among the Mayoruna of Brazil[vi] (the same group known as Matses on the Peruvian side of the border), and ensuing studies have revealed novel chemical compounds with a wide range of physiological and neurological activities.[vii]  Over 20 patents have since been registered on various compounds derived from Phyllomedusa venom, including dermorphin which is now synthesized and sold on-line.

Racehorse trainers have been known to use other exotic substances including cobra venom to improve horse performance and cheat at the tracks.  In addition to its analgesic effects, masking the pains of overexertion by horse or man, dermorphin appears to produce physiological excitement and euphoria.  Two of the horses testing positive for the substance in Louisiana had earned substantial purses.  As Louisiana's Racing Commission director Charles A. Gardiner III told the Times, “A lot of money’s got to be given back.” 

If only such ill-gotten winnings could be returned to the Matses…



[i]  Tastevin, C. Le fleuve Muru. La Geographie 43: 14-35.
[ii] Carneiro, R. 1970. Hunting and Hunting Magic among the Amahuaca of the Peruvian Montaña. Ethnology 9(4): 331-341; 
     Erikson, P. 1996. La griffe des aïeux: Marquage du corps et démarquages ethniques chez les Matis d’Amazonie. Paris: CNRS/Peeters; 
     Lima, E.C. 2005. Kampu, kampo, kambô: O uso do sapo-verde entre os Katukina. Revista do IPHAN 32: 254-267; 
     Carneiro da Cunha, M. Des grenouilles et des hommes. Télérama hors série, Les Indiens du Brésil. March, 2005: 80-83.
[iii] Gorman, P. 1993. Making magic: A Westerner glimpses one of the secrets of a tribe of hunter-gatherers in the Amazon. Omni Magazine 15(9): 64. July, 1993.
[iv] Wasson, G. 1957. Seeking the magic mushroom. Life Magazine, May 13, 1957.
[v] Lima E.C. & B.C. Labate. 2012. Kambo: From the forests of Acre to the urban centers. Erowid.org. May 31, 2012.
[vi] Milton, K. 1994. No pain, no game. Natural History 9: 44-51.
[vii] Daly, J.W., J. Caceres, R.W. Moni, F. Gusovsky, M. Moos, K.B. Seamon, K. Milton, and C.W. Meyers. 1992. Frog secretions and hunting magic in the upper Amazon: Identification of a peptide that interacts with an adenose receptor. Proceedings of the National Academy of Sciences 89(22): 10960-10963.