Keishi-bukuryo-gan is a traditional herbal medicine, which is used clinically as a vascular system disorder-eliminating drug. In this study, its effect on the progression of
diabetic nephropathy in experimental rats was investigated. The
diabetic nephropathy model used in this study shows functional and morphological changes of the kidney resembling those seen in patients with
diabetic nephropathy. Increased
proteinuria and serum
urea nitrogen and
creatinine levels and decreased
creatinine clearance, which are important parameters of renal function, were observed in rats with
diabetic nephropathy. Pathological examination of the kidney revealed diffuse, nodular and exudative lesions and arteriolar hyalinosis. The deterioration of renal function was ameliorated in rats treated with
Keishi-bukuryo-gan for 15 weeks and these results agreed with the renal histological findings. In addition, metabolic abnormalities mediated by persistent hyperglycaemia (the glycation reaction, excessive
polyol pathway activity, oxidative stress and
lipid metabolic abnormalities) were also observed. However,
Keishi-bukuryo-gan reduced accumulation of
advanced glycation end products, determined by measuring fluorescence, and serum lipid peroxidation,
triglyceride and total
cholesterol levels dose-dependently. Thus, this study indicates the potential therapeutic usefulness of
Keishi-bukuryo-gan for retarding the progression of renal damage and suggests that its beneficial effects were due to its ability to improve metabolic abnormalities associated with diabetes.