Diabetes Care, Vol 20, Issue 6 995-998, Copyright © 1997 by American Diabetes Association
Epalrestat, an aldose reductase inhibitor, improves an impaired generation of oxygen-derived free radicals by neutrophils from poorly controlled NIDDM patients
N Sato, K Kashima, Y Uehara, K Ohtani, H Shimizu and M Mori
First Department of Internal Medicine, Gunma University School of Medicine, Japan.
OBJECTIVE: To study the in vivo effect of epalrestat (Epa), an aldose
reductase inhibitor, on the generation of oxygen-derived free radicals by
neutrophils from poorly controlled NIDDM patients (HbA1c > 10%).
RESEARCH DESIGN AND METHODS: A total of 31 diabetic patients were randomly
divided into two groups: an Epa(+) group of 16 patients treated with 150
mg/day epalrestat and an Epa(-) group of 15 patients treated without
epalrestat. A control group of 20 age- and sex-matched normal healthy
subjects also participated. HbA1c, postprandial plasma glucose (PPG), and
neutrophil bactericidal function were measured before and at the end of the
drug treatment period (4 weeks). Neutrophil bactericidal function was
measured as chemilu-minescence amplified by a Cypridina luciferin analog
(CLA), which is dependent on O2- generation, and by luminol (L), which is
highly dependent on OCl- generation, in response to
formyl-methonyl-leucyl-phenylalanine (fMLP). RESULTS: At the start of the
experiment, both CLA-dependent chemiluminescence (CLA-DCL) and L-dependent
chemiluminescence (L-DCL) were clearly decreased in diabetic subjects (64
and 54%, respectively; P < 0.05) compared with control subjects (2,182
+/- 144 and 3,221 +/- 173 kc.min-1.10(-6) cells, respectively). At the end
of the experiment, CLA-DCL and L-DCL in the Epa(+) group were significantly
improved by 44 and 46%, respectively; however, these values were still
lower than the corresponding results in the control group. HbA1c and PPG in
both the Epa(+) and Epa (-) groups were significantly higher than in the
control group, and treatment had no effect on either HbA1c or PPG.
CONCLUSIONS: These data suggest that epalrestat may be a useful drug to
prevent infection by improving the impaired O2- and OCl- generation by
neutrophils from poorly controlled NIDDM patients.