ObjectiveTo assess the renal benefits of cicletanine (CIC) in diabetic rats with renal impairment.MethodsHemi-nephrectomized streptozotocin-diabetic Wistar–Kyoto Izmo rats (WKYIzm) (10 weeks old) were randomly assigned to receive vehicle or a low or high dose of CIC (30 or 100 mg/kg per day, orally) for 12 weeks.ResultsThe blood pressure was raised slightly but not significantly in this model. An anti-hypertensive effect of CIC was not significantly observed. However, the subdepressor doses of CIC significantly and dosedependently decreased urinary albumin excretion. These results were confirmed by morphological analysis of kidneys in each group of rats. CIC treatment significantly and effectively protected against an increase in the percentage of focal glomerular sclerosis. CIC did not affect urinary and blood glucose concentrations at either dose.ConclusionsThese results suggest that CIC has a renal-protective action, which is not related to improvement of diabetes or of high blood pressure in this model. The action might be due to the reduction of intraglomerular capillary pressure, although the mechanism remains to be further investigated.