Presence of a tumor-promoting factor in honey.

Honey samples collected from the Saidabad area of Azarbaijan province of Iran were found to be moderately irritant, and this activity was associated with the presence of tri-acylates of the diterpene ingenol, which are transferred from the nectar of Euphorbia seguieriana Neck by honey bees to the honey. The acylates of ingenol are known promoters of carcinogenesis.