Measurement of α-dicarbonyl compounds in human saliva by pre-column derivatization HPLC

Background: a-Dicarbonyl compounds (alpha-DCs) have been detected in body fluids including plasma and urine and elevation of this sort of compounds in vivo has been associated with the development of many kinds of chronic diseases. However whether alpha-DCs are present in human saliva, and if their presence/absence can be related with various chronic diseases is yet to be determined. Methods: In this study, a pre-column derivatization HPLC-UV method was developed to measure 3-deoxyglucosone (3-DG), glyoxal (GO), methylglyoxal (MGO), diacetyl (DA), and pentane-2,3-dione (PD) in human saliva employing 4-(2,3-dimethyl-6-quinoxalinyl)-1,2-benzenediamine (DQB) as a derivatizing reagent. The derivatization of the alpha-DCs is fast and the conditions are facile. The method was evaluated and the results show that it is suitable for the quantification of alpha-DCs in human saliva. Results: In the measurements of these alpha-DCs in the saliva of 15 healthy subjects and 23 type 2 diabetes mellitus (T2DM) patients, we found that the concentrations of GO and MGO in the saliva of the diabetic patients were significantly higher than those in healthy subjects. As far as we know, this is the first time that salivary alpha-DC concentrations have been determined and associated with T2DM. Conclusions: The developed method would be useful for the measurement of the salivary alpha-DC levels and the data acquired could be informative in the early screening for diabetes.