In vitro glycation induced cross-linking inhibition of selected plants of Sri Lanka

Abstract

Advanced glycation end products (AGEs) are stable irreversible compounds formed by non-enzymatic reaction of amino groups of proteins with reducing sugars. Accumulation of AGE leads to protein cross-linking which enhances the complications of diabetes. Glycation inhibition can slow down the production of AGEs and protein cross-linking with reduction in the pathogenesis of diabetic complications. The objective of the study was to evaluate glycation induced protein cross-linking inhibitory potential of five selected plant extracts. Fruits of Bunchosia armeniaca (Malpighiaceae), Garcinia zeylanica (Clusiaceae), leaves of Coleus hadiensis (Lamiaceae) (Synonym: Plectranthus zatarhendi), roots of Hibiscus furcatus (Malvaceae) and seeds of Gossipium sp. (Malvaceae) were selected and dried under shade. Dried plant parts were sonicated and extracted to methanol or methanol:dichlormethane 1:1 mixture. Solvents were evaporated using rotary evaporation at 40◦C to obtain extracts of each plant part. Inhibition of glycation induced protein cross-linking was evaluated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Results of in vitro assays showed that except B. armeniaca, all plant extracts inhibited the glycation induced protein cross-linking. G. zeylanica showed the highest inhibitory potential among the five selected plants. With G. zeylanica complete inhibition of glycation induced protein cross-linking was observed at 0.2 mg/ml even after 26 days and with concentration as low as 50 μg/ml after 11 days. Based on the results it can be concluded that the fruits G. zeylanica, leaves of C. hadiensis, roots of H. furcatus and seeds of Gossipium sp. have the potential to reduce diabetes associated complications caused by AGEs.