In this study, we investigated whether Keishi-bukuryo-gan can retard the occurrence and progression of diabetic nephropathy in spontaneously diabetic WBN/Kob rats. Administration of Keishi-bukuryo-gan did not affect body weight loss or blood glucose levels but effectively lowered urinary protein excretion and serum creatinine levels, and ameliorated glomerular, vascular and tubulointerstitial lesions. In addition, treatment of the diabetic rats with Keishi-bukuryo-gan reduced renal levels of thiobarbituric acid reactive substances and advanced glycation end products significantly and elevated renal superoxide dismutase activity significantly. These results suggest that Keishi-bukuryo-gan exerts antioxidant effects in the kidneys of diabetics and may prove that the herbal medicine is useful for inhibiting the progression of diabetic kidney disease. 本研究では,自然発症糖尿病WBN/Kobラットを用い,桂枝茯苓丸が糖尿病性腎症の発症・進展を遅延するか否かについて検討した。その結果,体重と血糖値に対しては,桂枝茯苓丸投与による変化は見られなかったが,尿蛋白排泄量と血清クレアチニンレベルが有意に低下し,病理組織所見(糸球体硬化,血管病変,間質・尿細管障害)も改善していた。一方,腎組織中の過酸化脂質とadvanced glycation end productsレベルは,桂枝茯苓丸投与群で有意に低下し,スーパーオキシドジスムターゼ活性は有意に上昇していた。これらの結果より,桂枝茯苓丸は糖尿病ラットの腎臓において抗酸化作用を発揮し,腎症の進展抑制に有用であることが示唆された
