&i&In Vitro&/i& Evaluation of the Potential Antioxidant of &i&Bidens segetum&/i& Mart. ex Colla (Asteraceae) in Melanocyte and Melanoma Cells

摘要

Bidens segetum Martius ex Colla known as the “pic ã o do mato”, is an herbaceous plant that occurs in the Cerrado biome of some Brazilian states. Among the species of Bidens , we highlight B. pilosa known as “pic ã o preto”, of which several activities are reported as antioxidant and antibacterial. Ethanolic extract from Bidens segetum (EEBs) showed an-tioxidant potential when analyzed by free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and antifungal activity against Cladosporium cladosporiodes and C. sphareospermum fungi. PFFR3.3 subfraction from EEBs has 81.5% of 5-O caffeoylquinic acid (5-CQA) and potential antioxidant (DPPH). However, PFFR3.3 did not decrease superoxide anion in metastatic melanoma cells by dihydroeth-idium assay (DHE). PP4 subfraction is a mixture of polyacetylenes that has antifungal ( Cladosporium ) and antioxidant activity, since reduced superoxide anion amount in melanoma cells after 5 min of treatment. However, no dose-response and time-response curve were observed, not even with the authentic standard (5-CQA). Complementary chemical studies will be performed to confirm the polyacetylenes and 5-CQA structures present in the EEBs from B. segetum and new methodologies should be performed to confirm the antioxidant activity of these com-pounds and the effects on melanocytes and melanomas.