Antioxidative activity of glycoprotein isolated from Geranium sibiricum Linne.

Glycoprotein from Geranium sibiricum Linne (GSL) with 18 kDa was isolated and it consists of carbohydrate moiety (10.45%) and protein moiety (89.55%). The GSL glycoprotein was characterised by its radical scavenging activity under various experimental conditions. When GSL glycoprotein was treated with deactivation agents (pronase E or NaIO(4)), its scavenging activity decreased in both cases. It has optimal and maximal activity in acidic, neutral pH (up to pH 9), and up to 85 degrees C. Also, its activity reduced in the case of Ca(2+) and Mn(2+), with the exception of the Mg(2+) case. Its activity in the presence of Mn(2+) declined more than in the case of the Ca(2+). Also, GSL glycoprotein (500 microg mL(-1)) has antioxidative effects on hydroxyl and superoxide anion radicals in cell-free systems, and GSL glycoprotein (200 microg mL(-1)) significantly protected from cytotoxicity in the GO (100 mU mL(-1))-treated Chang liver cells for 4 h.