Negative effect of noscapine on human serum albumin glycation

Abstract

Introduction: Glycation, one of the post-translational modifications of proteins, is a
nonenzymatic reaction initiated by the primary addition of sugar to the amino groups
of proteins. In the early stage of glycation, the synthesis of intermediates leads to the
formation of Amadori compounds. In the late stage, advanced glycation end products
(AGE) are irreversibly formed after a complex cascade of reactions. It has recently
become clear that glycation also affects diabetes-related complications and Alzheimer’s
disease. The main aim of this investigation is to provide direct evidence for the effects
of Noscapine on HSA glycation. Materials and Methods: In this study human serum
albumin (HSA)(10 mg / ml) was incubated in phosphate buffered saline (PBS) (50 mM)
with Glucose (40 mM) and different concentrations of Noscapine (25, 100, 250, 500
µM), for 42 days, at 37˚C, as also HSA was incubated alone (control or H), with Glucose
(40mM) (glycated or H + G), respectively, under the same conditions. After incubation
the samples were prepared for circular dichroism (CD) and Fluorescencetechniques.
Statistical Analysis Used: The results were expressed as mean ± SEM and chi square test
was significant at P < 0.05. Results: In glycated sample CD and Fluorescence showed
more change relative to the control sample, but in the presence of different Noscapine
concentrations and Glucose there were no significant changes relative to the glycated
sample. Conclusions: Thus, this study suggests that Noscapine is not responsible for
the antiglycation effect.