Premium
Antioxidant Activity of Puha ( Sonchus oleraceus L.) as Assessed by the Cellular Antioxidant Activity (CAA) Assay
Author(s) -
McDowell Arlene,
Thompson Scott,
Stark Mirjam,
Ou ZongQuan,
Gould Kevin S.
Publication year - 2011
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.3648
Subject(s) - antioxidant , dpph , polyphenol , nutraceutical , chemistry , traditional medicine , food science , methylene blue , mtt assay , biochemistry , in vitro , medicine , photocatalysis , catalysis
There is considerable interest in antioxidant dietary components that can be protective against degenerative diseases in humans. Puha ( Sonchus oleraceus L.) is a rich source of polyphenols, and exhibits strong antioxidant activity as measured by the 2,2‐diphenylpicrylhydrazyl (DPPH) assay. However, the potential of puha to protect against degenerative diseases requires that low molecular weight antioxidants (LMWA) are absorbed by, and active in, human cells. The cellular antioxidant activity (CAA) assay was used to investigate the antioxidant activity of puha leaf extracts. Preparation methods of freezing and freeze‐drying reduced the total polyphenolic content compared with fresh puha, but did not affect the LMWA potential as determined by the DPPH assay. The IC 50 values were 0.012 ± 0.003 mg/mL and 0.010 ± 0.005 mg/mL for freeze‐dried and fresh puha leaves, respectively. Using the CAA assay, it was shown that LMWAs from foliar extracts of puha were effectively absorbed into HepG2 cells, and exerted antioxidant activity at levels comparable to those of extracts from blueberry fruits, the much‐touted antioxidant superfood. Methylene blue staining of HepG2 cells indicated that puha extracts were not cytotoxic at concentrations below 100 mg DW/mL. The data indicate the potential of puha as a nutraceutical supplement for human health. Copyright © 2011 John Wiley & Sons, Ltd.