Article ID: b14-00034
Advanced glycation end-products (AGEs) have been implicated in the development of diabetic complications. We report the antiglycating activity of chebulic acid (CA), isolated from Terminalia chebula on breaking the cross-links of proteins induced by AGEs and inhibiting the formation of AGEs. Aminoguanidine (AG) reduced 50% of glycated BSA with glycolaldehyde (glycol-BSA)-induced cross-links of collagen at a concentration of 67.8 ± 2.5 mM, the level of CA required for exerting a similar antiglycating activity was 38.8 ± 0.5 mM. Also, the breaking activity on collagen cross-links induced by glycol-BSA was potent with CA (IC50 = 1.46 ± 0.05 mM), exhibiting 50-fold stronger breaking activity than with ALT-711, a well-known cross-link breaker (IC50 = 72.2 ± 2.4 mM). IC50 values of DPPH• scavenging activity for CA and ascorbic acid (AA) were 39.2 ±4.9 and 19.0 ±1.2 mg dry matter (DM) mL-1 , respectively, and ferric reducing and antioxidant power (FRAP) activities for CA and AA were 4.70 ±0.06 and 11.4 ±0.1 mmol/FeSO4•7H2O/g DM, respectively. The chelating activities of CA, AG and ALT711 on copper-catalyzed oxidation of AA were compared, and in increasing order, ALT-711(IC50 of 1.92 ±0.20 mM) <CA (IC50 of 0.96 ± 0.07 mM ) <AG (0.47 ±0.05 mM). Thus, CA could be a breaker as well as an inhibitor of AGE cross-linking, the activity of which may be explained in large part by its chelating and antioxidant activities, suggesting that CA may constitute a promising antiglycating candidate in intervening AGE-mediated diabetic complications.
