Inhibitory effect of vitamin B3 against glycation and reactive oxygen species production in HSA: An in vitro approach.

Hyperglycaemia is a key factor for the formation of advanced glycated endproducts (AGEs). Inhibition of glycation may play key role in minimizing the diabetes related complications. We have tried to explore the glucose and methyl glyoxal mediated glycation and antiglycation activity of niacin using human serum albumin as model protein. Protein was incubated with glucose for 28 days at physiological temperature to achieve glycation. Antiglycation activity was evaluated by assessing free lysine, carbonyl content, AGE specific fluorescence. Molecular docking and isothermal titration calorimetry was deployed to study the interaction of niacin with HSA and get a detailed insight of binding site and thermodynamics of interaction. Niacin reduced the glycation significantly which was evident from the estimation of free lysine and carbonyl content. Niacin binds with HSA in a spontaneous manner with the binding constant in the range of 104 M-1. Niacin also prevented the loss in secondary structure induced by glycation. Reactive oxygen species were also effectively quenched by niacin leading to protection from DNA damage. Niacin was found to be located at Sudlow's site I with binding energy of 5.3 kcal/mol. These results clearly highlight the antiglycation activity of niacin and its potential in preventing disease progression in diabetes.