Bioactivities of Piper aduncum L. and Piper obliquum Ruiz & Pavon (Piperaceae) essential oils from Eastern Ecuador

Essential oils from aerial parts of Piper aduncum (Matico) and Piper obliquum (Anis del Oriente) of ecuadorian origin were analyzed by GC–FID, GC–MS, 13C NMR and their biological and pharmacological activities were assessed. Chemical composition proved to be unusually different from previous reports for safrole-rich P. obliquum (45.8%), while P. aduncum main constituent was dillapiol (45.9%). No genotoxic activity was found in the Ames/Salmonella typhimurium (TA98 and TA100) assay, either with or without S9 activation. Mutagen-protective properties, evaluated using sodium azide, 2-nitrofluorene and 2-aminoanthracene as mutagens/promutagens, was observed against promutagen 2-aminoanthracene, likely in consequence of microsomial deactivation. Antimicrobial assays have been performed on Gram+/Gram− bacteria, dermatophyte and phytopathogenic fungi and best results were provided by P. aduncum against fungal strains with complete inhibition at 500 μg/ml. Preliminary analgesic and antithrombotic activities evidenced the absence of the former in hot plate and edema assays and a limited antiplatelet action against three different agonists (ADP, AA and U46619). Both oils have a very limited antioxidant capacity.