Scavenging and antioxidant activities of immunomodulating polysaccharides isolated from Salvia officinalis L.

Crude polysaccharides, isolated from the aerial parts of sage (Salvia officinalis L.) by sequential extraction with water (A), hot ammonium oxalate (B), dimethyl sulfoxide (C), 1 M (D) and 4 M (E) potassium hydroxide solutions, and six ion-exchange fractions of A were examined for their ability to inhibit peroxidation of liposome lipid by hydroxyl radicals and to reduced DPPH center dot radical content. The highest inhibition of liposome lipid peroxidation was found with crude polysaccharides A, B and D, antioxidant activities reached similar to 37%. The purified fractions A1 and A2 inhibited the liposome peroxidation to similar to 35%. However, the radical scavenging abilities of the most active crude polysaccharides A, B and C on DPPH center dot radicals were found in the range 80-90%, while the most active purified fractions A(3)-A(6) in three or fourfold doses achieved 75-92%. The least effective tested polysaccharides succeeded 20% inhibition using both methods. (C) 2008 Elsevier B.V. All rights reserved.