Traditional Medicine, Ceramic Vessels, and Organic Residues: Chemical Evidence for Euphorbiaceae Processing in Samoa 2000 years ago

 Unexpected, complex FTIR (Fourier Transform Infrared Spectroscopy) signatures obtained on Samoan ceramic sherds containing organic residues and dating approximately 2000 years ago suggest medicinal plant processing.  Although originally intended as a study of food residues, signatures obtained from these ceramic sherds matched with signatures for the milky, white sap common in plants in the Euphorbiaceae, taking the study in the direction of prehistoric medicine.  Homalanthus (mamala) and Aleurites (kukui nut) both grow in Samoa and are the most likely sources of the signatures obtained.  Homalanthus was used as a traditional medicinal treatment for hepatitis in Samoa.  Processing Homalanthus yields the anti-viral drug prostratin, which also has been studied as a potential cure for HIV.   Matches for some of the peaks with Pandanus bark suggests the use of hala keys as brushes or scoops and indicates that the signature obtained from these sherds represents the presence of more than one plant.