Potentially toxic chemicals, andromedo-toxins, are present in substantial amounts in Rhododendron ponticum. These chemicals include 'free' phenols and diterpenes. The diterpenes, also known as grayanotoxins, are mainly found in the leaves, flowers, and nectar. The phenols are typically found in new tissues. The toxins affect the sodium channels by blocking them and preventing voltage-dependent inactivation in the cell membrane, leaving cells depolarized.

     Animals, such as sheep and cattle, can become poisoned after ingesting the toxic chemicals from Rhododendron ponticum. However, it typically requires the organism to intake a substantial amount of the chemicals. Since the leaves are unpalatable to these animals, the animal is typically starved and therefore desperate for food.

    When humans are poisoned by the toxins in Rhododendron ponticum, it is typically because they consumed honey products from Rhododendron ponticum flowers.  This is known as Honey-intoxication or Mad Honey Disease.
    Symptoms include intestinal and cardiac problems, and rarely death. The level of severity is dependent upon the amount of chemicals consumed. To treat most cases, replenishing fluids and taking a low dose atropine is typically adequate.

©Waugsberg 2007


Nutrition of Rhododendron ponticum