Piper umbellata leaves accumulate the compound, 4-nerolidylcatechol, which is responsible for the antioxidant power of the plant. Surprisingly, in this study we observed a significant increase in the antioxidant activity of P. umbellata leaves after their metabolism on Heraclides brasiliensis larvae. The total phenolic concentrations of the extracts from the leaves and fecal matter (metabolized leaves) measured using the Folin-Ciocalteu reagent, were 14.78 and 27.13 mg GAE/g, respectively. The antioxidant activity, based on 2,2-azinobis 3-ethylbenzothiozoline-6-sulfonic acid (ABTS), was EC₅₀ of 120.10 and 62.50 ug/ml for the leaves and fecal material, respectively. These values were correlated with the total phenolic content.

Key words: Piper umbellata, Heraclides brasiliensis, antioxidant, metabolism.