A traditional method of Cinnamomum carolinense preparation eliminates safrole from a therapeutic Pohnpean tea

Cinnamomum carolinense, locally known as madeu, is a tree endemic to the volcanic mountains of the Island of Pohnpei in the Eastern Carolines of the South Pacific. The bark is harvested from trees and brewed to make a medicinal tea and hot beverage that is regularly consumed. Many species of Cinnamomum contain the known hepatocarcinogen safrole, sparking concern regarding habitual consumption of this beverage. HPLC-PDA analysis confirmed the presence of the carcinogen in alcoholic extracts of Cinnamomum carolinense bark shavings (0.435%, w/w), but safrole was not detected in the tea. The limit of detection and limit of quantitation of safrole were determined to be 1.25 and 3.75 μg/mL, respectively. The traditional preparation method, which boils the bark shavings, degrades the safrole.