Antioxidant activity of extracts from leaves and roots of Salvia miltiorrhiza Bunge, S. przewalskii Maxim., and S. verticillata L.

Three Salvia species have been studied for antioxidant activity in methanol extracts from roots and leaves. The presence of the polyphenols and tanshinones was screened by HPLC and spectrophotometric assays and related to the antioxidant potential. The antioxidant capacity of the studied species is high, but differences between species and organs have been also revealed. Salvia przewalskii leaf extract was the strongest one in all tests, followed by Salvia miltiorrhiza root and Salvia verticillata leaf. Among the roots, the most active was S. miltiorrhiza extract, followed by S. verticillata. The antioxidant activity correlates to the total polyphenol and, depending on the assay, to the hydroxycinnamic acids content. The high content of tanshinones in both S. miltiorrhizza and S. przewalskii roots is unlikely to contribute to the antioxidant activity. (C) 2008 Elsevier Ltd. All rights reserved.