Bioactive compounds in Bidens pilosa L. populations: a key step in the standardization of phytopharmaceutical preparations

The total flavonoid content (TFC), total polyphenols content (TPC), and in vitro antioxidant activity (AA) of six Bidens pilosa L., Asteraceae, populations harvested from different localities were evaluated in this work. The plants were separated in roots, stems, and leaves/flowers, and the influence of extraction methods was investigated. A reversed-phase high-performance liquid chromatography method (HPLC) was developed and employed to obtain characteristic HPLC fingerprints of the bioactive compounds present in the extractive solutions, which were correlated with the TFC, TPC, and AA. Extractive solutions of leaves/flowers presented a higher AA when compared with those obtained from other parts of the plant (IC50 of 35.35 +/- 0.10 mu g/mL). The stem extracts presented the lowest AA (IC50 117.2 +/- 1.96 mu g/mL). A direct correlation of AA with TFC and TPC was evidenced. The highest AA was obtained by dynamic maceration and was statistically different from the AA presented by the extractive solutions obtained by other extraction methods. The results of this work evidenced differences that can be found at different stages of development of phytopharmaceutical preparations from B. pilosa and highlighted the importance of using the concentration of marker compounds as well as HPLC fingerprints as quality control parameters.