Oral safety and tolerability of Eucalypt and Corymbia sap resins in healthy adults – A randomised controlled study

This study aims to determine safety and gastrointestinal tolerance of a novel ingredient for internal use up to a period of 14 days. This project is testing the safety of a traditional Australian Indigenous ingredient in a modern context. The sap resin produced by several species of eucalypts (gum trees) has an extensive history of oral use, however, the safety aspects have never been investigated. The purpose of this study is to demonstrate safety of a selection of sap resins taken from a range of different Eucalypt species (both Eucalyptus and Corymbia), in a modern context, at a standardised dose. The dosage form (in capsules) is not in accordance with traditional use (dissolved in water) and the ingredient has not been tested in this form before. The evidence of therapeutic internal use of this ingredient details a primary use of sap resin for digestive complaints. The potent astringent properties and ability to stem the secretion of body fluids have been detailed as the primary action for its effectiveness as a remedy for upset stomachs, diarrhoea and dysentery. The duration of use in the historical literature is not described, and it is expected, due to the primary use of this ingredient, to have been limited to short-term use, perhaps a few days to a week. Given the potential modern-day use of a mucilaginous astringent may extend to conditions such as diarrhoea predominant irritable bowel syndrome, the safe use of the ingredient for a period up to two weeks was chosen to be evaluated. The potential benefit of this research is to demonstrate the safe use of this ingredient internally at a standardised dose over a two-week period.