Protein glycation inhibitory and antioxidative activities of some plant extracts in vitro.

The protein glycation inhibitory activity of aqueous ethanolic extracts from 25 plant tissues was evaluated in vitro using the model system of bovine serum albumin and fructose. The most bioactive plant tissue was Allium cepa (skin), followed by Illicium religiosum (bark and wood), Fagopyrum esculentum (hull), Origanum officinalis (leaf), Rosmarinus officinalis (leaf), Pyrus pyrifolia (bark),Acanthopanax senticosus (bark), Eugenia caryophllata (leaf), and Erigeron annuus (whole). The extracts with glycation inhibitory activity also showed antioxidative activity when a micellar linoleic acid peroxidation system was applied followed by 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assays. The glycation inhibitory activity was significantly correlated with the antioxidative potency of the extracts. The positive glycation inhibitory and antioxidative activities of these plants might suggest a possible role in targeting aging and diabetic complications.