Mad Honey Poisoning
Anastacia Griego
May 4, 2007
Overview
 We will look at the source of mad honey
poisoning as well as the involved toxin’s
mechanism of action and the signs and
symptoms of this condition
Source
 Mad Honey Poisoning, also known as
“Honey Intoxication” is caused by
consuming honey containing the
neurotoxic substance called grayanotoxin
Source
 Grayanotoxin is found in some species of
the Rhododendron, most notably
Rhododendron ponticum, which is native
to Turkey
Sources
 In the United States, there are several
plants related to the rhododendron which
also produce grayanotoxins. These
plants include2:
 Rhododendron occidentale (western azalea)
 Rhododendron macrophyllum (California
rosebay)
 Rhododendron albiflorum
Origin
 Bees gather the
grayanotoxin containing
pollen and nectar from
the rhododendron
 Toxin is retained in the
honey produced from
the poisonous flower
products
Toxin
 There are three main types of
grayanotoxin, the least toxic of these is
grayanotoxin I with an LD50 of 4 mg/kg.
Toxin
 The LD50 for grayanotoxin II is 1.3 mg/kg
in mice
Note to self:
Those
 Most toxic honeys
injections
are not for
my benefit…
only contain 0.1
to 0.5 mg/mL
Toxin
 There are only a few cases of mad honey
poisoning reported each year. Usually
from eating tainted honey from Turkey
 Mad honey has been used as an
alternative therapy for some conditions
including gastrointestinal diseases and
some poisonings have been linked to this
usage1
Toxin
 Although the incidence of grayanotoxin
poisoning is rare, there is concern that
the number of cases per year will rise
with the increasing demand for organic
products
Mechanism
 Grayanotoxin targets the
nervous system, specifically
the gated sodium ion
channels which are involved
in the initiation and
propagation of action
potentials across the plasma
membrane of the nerve cell.
Mechanism
 Grayanotoxins bind Na+
channels in nerve cells. Gated
Na+ channels bound to
grayanotoxin can be stimulated
to open at membrane
potentials lower than those that
trigger opening of normal Na+
channels2
Mechanism
 Grayanotoxin is also able to inhibit
closing of the Na+ channel once it is
open3
 The end result is hyper-stimulation of the
nerve cell
Signs and Symptoms
 Signs and symptoms of grayanotoxin
poisoning rarely last more than 24 hours
and are usually not fatal2
 Most symptoms are mild and resolve
themselves without medical intervention
Signs and Symptoms
 Some signs of mad honey poisoning include1:








Bradycardia
Cardiac arrhythmia
Hypotension
Nausea and Vomiting
Sweating
Chills
Salivation
Dizziness
Signs and Symptoms
 Signs of mad honey poisoning (cont)1:






Weakness
Loss of consciousness
Fainting
Blurred vision
Paresthesia
Cyanosis
Grayanotoxin in History
 The Anabasis recounts the adventures of
the Greek army that was sent to aid the
Persian army under Cyrus. In 401 B.C.
the Greeks sent to aid the Persians
became ill after eating some mad honey,
but all recovered within 24 hours of
consumption7
Grayanotoxin in History
 Hundreds of years later, a troop of
soldiers from Pompey was poisoned with
mad honey and ambushed while
overcome by the symptoms of the
poisoning5
References
1.
Dilber, Embiya, et al. A Case of Mad Honey
Poisoning Presenting with Convulsion: Intoxication
Instead of Alternative Therapy. Turk J Med Sci 32
(2002) 361-362
2.
Grayanotoxin. accessed April 29, 2007, from
http://www.cfsan.fda.gov/~mow/chap44.html
3.
Kimura, Takahiro, et al., Novel Site on Sodium
Channel α-Subunit Responsible for the Differential
Sensitivity of Grayanotoxin in Skeletal and Cardiac
Muscle. Molecular Pharmacology. 60 (2001) 865-872
References
4.
Lee, S.W., et al. Grayanotoxin Poisoning From Flower of
Rhododendron mucronulatum in Humans. Bull Environ Contam
Toxicol. 2007
5.
Sheir, Thomas. Handbook of Toxinology. accessed May 3, 2007 from
http://books.google.com/books?id=6oUdkb1hUCYC&pg=PA513&lpg=P
A513&dq=ld50+for+grayanotoxin&source=web&ots=eWV9bqNokk&sig
=0ujk-ViIP-AB1LDxAlmrMNlVKdM
6.
Sulivan, Ron. “Behold the lovely rhododendron -- and beware its
maddening toxins” San Francisco Chronicle February 9, 2005 pg. HO-5
7.
Xenophon, Anabasis translation by H. G. Dakyns online, courtesy of
Project Gutenberg, accessed May 3, 2007 from
www.fordham.edu/halsall/ancient/xenophonanabasis.html#Project%20Gutenberg