EVALUATION OF THE EFFECTS OF ASCORBIC ACID ON GLYCATION REACTION OF ALBUMIN ON IN VITRO CONDITION

Advanced glycation end products (AGEs) formation is increased in diabetes
mellitus, leading to microvascular and macrovascular complications. Recently, much attention has been
focused on natural and synthetic inhibitors to delay the onset or progression of diabetes and its
comorbidities. In this study, an in vitro glycation model containing albumin as a model protein together
with glucose as glycating agent was used to study antiglycation activity of AA.
Materials & Methods: Bovine serum albumin was incubated with 0.5 M of glucose with or without AA
in 37°C for 4 weeks. The formation of fluorescent AGEs was determined to indicate protein glycation,
whereas the level of protein carbonyl content and thiol group were examined for protein oxidation.
Glycation is known to induce aggregation and fibrillation of proteins. To determine the inhibitory effect
of AA on aggregation and fibrillation of albumin, amyloid specific dyes such as Thioflavin T was used.
Results: The results found that AA significantly inhibited the formation of fluorescent AGEs (P < 0.05)
and significantly prevented protein oxidation manifested by reducing protein carbonyl and the depletion
of protein thiol groups (P < 0.05). Moreover, our results indicated the inhibitory potential of AA toward
amyloid like aggregation of albumin and protective effect of AA on albumin native conformation.
Conclusion: Thus, these findings indicated that AA has high potential for decreasing protein glycation
and oxidation that may delay or prevent AGEs-related diabetic complications