Inhibitors of
advanced glycation end products (AGEs) have potential as preventive agents against
diabetic complications. In-vitro AGE inhibitory activity, transition
metal chelating, and
free radical scavenging activity tests have been used to screen for and identify effective AGE inhibitors. In an ongoing project to elucidate AGE inhibiting active components of heat-processed ginseng,
maltol was selected for more detailed investigation. Although there are several lines of evidence concerning the
antioxidant activity of
maltol, the in-vitro and in-vivo inhibitory effects of
maltol on AGE generation have not been evaluated. In the present study, the in-vitro AGE inhibitory effects and
free radical scavenging activity of
maltol were investigated. In addition, the in-vivo therapeutic potential of
maltol against diabetic renal damage was tested using
streptozotocin (STZ)-diabetic rats.
Maltol showed a stronger AGE inhibitory effect than
aminoguanidine, a well known AGE inhibitor. In addition, the
hydroxyl radical scavenging activity of
maltol on electron spin resonance (ESR) spectrometry was slightly stronger than that of
aminoguanidine. Therefore,
maltol was found to have stronger in-vitro AGE inhibiting activity compared with
aminoguanidine. The administration of 50 mgkg(-1) per day of
maltol suppressed the elevated serum levels of
glycosylated protein, renal fluorescent AGEs,
carboxymethyllysine, receptors for AGEs, and
nuclear factor-kappaB p65 in diabetic control rats. These beneficial effects of
maltol against STZ-diabetic renal damage were thought to result from its
free radical scavenging and AGE inhibitory effects.