Strong Protein Glycation Inhibitory Potential of Clove and Coriander

Aims: Protein glycation mediates almost all chronic diabetic complications associated with hyperglycaemia. In view of searching for safe antiglycating agents from nature, the protein glycation inhibitory potential of three spices was determined using a novel, electrophoresis based method.
Study Design: Dry plant parts, standard inhibitor, extraction, in vitro glycation model, gel electrophoresis.
Place and Duration of Study: Department of Biochemistry, Faculty of medicine, University of Peradeniya, Sri Lanka, between June 2012 and December 2013.
Methodology: Methanolic extracts of dried Coriandrum sativum (Coriander) seeds, Cinnamomum zeylanicum (Cinnamon) bark and Syzygium aromaticum (Clove) flower buds were used. Bovine serum albumin (BSA) was incubated with fructose in phosphate buffer (pH 7.4) at 37ºC for 30 days in the presence or absence of the extracts. Corresponding blanks, controls and the standard glycation inhibitor aminoguanidine were included. Aliquots were collected at intervals and analyzed using polyacrylamide gel electrophoresis under non denaturing conditions (PAGE). Antiglycating effects of the extracts were assessed based on the decrease in migration of BSA.
Results: Previously, we have demonstrated using PAGE, that the increase in BSA migration, in comparison to the blank is proportionate to the degree of glycation. In presence of C. sativum and S. aromaticum,migration of BSA was reduced with extract concentrations as low as 10 µg/ ml, compared to its migration in absence of the extract (positive control), indicating strong glycation inhibitory effects of the extracts. C. zeylanicum showed antiglycating effects at 5 mg/ ml but not at 0.5 mg/ ml.
Conclusion: This study revealed strong protein glycation inhibitory effects in C. sativum and S. aromaticum. C. zeylanicum showed a comparatively lower inhibition.