ABSTRACT The prevention of chronic and degenerative
diseases, is a
health concern deeply associated with
oxidative stress. Such progressive phenomena can be avoided through exogenous
antioxidant intake, which set up a
reductant cascade, mopping up damaging
free radicals.
Medicinal herbs are commonly associated with high
antioxidant potential, and hence their
health benefits. The
commerce of dried
herbal extracts
movements a big portion of
developing countries economy. The
determination of
medicinal herbs the
antioxidant activity capacity is of utmost importance. The assessment of
antioxidant activity in phytotherapics is mostly achieved by spectrophotometric assays, however colored substances can produce interferences that do not occur in electroanalytical
methods. Therefore, the aim of this
paper is to compare spectrophotometric and voltammetric
techniques to evaluate
antioxidant activity in
herbal drugs such as
Ginkgo biloba L.,
Camellia sinensis (L.) Kuntze,
Theaceae;
Hypericum perforatum L.,
Hypericaceae;
Aesculus hippocastanum L.,
Sapindaceae;
Rosmarinus officinalis L.,
Lamiaceae;
Morinda citrifolia L.,
Rubiaceae;
Centella asiatica (L.) Urb.,
Apiaceae;
Trifolium pratense L.,
Fabaceae;
Crataegus oxyacantha L.,
Rosaceae; and
Vaccinium macrocarpon Aiton,
Ericaceae. The spectrophotometric
methods employed were DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-
sulfonic acid) and the Folin-Ciocalteu assays. The electroanalytical
method used was voltammetry and it was developed a
phenoloxidase based
biosensor. The
redox behavior observed for each
herbal sample resulted in distinguishable voltammetric profiles. The highest electrochemical indexes were found to G. biloba and H. perforatum, corroborating to traditional spectrophotometric
methods. Thus, the electroanalysis of
herbal drugs, may be a promising tool for
antioxidant potential assessment.