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Evidence-Based Complementary and Alternative Medicine
Volume 7, Issue 4, Pages 433-440
http://dx.doi.org/10.1093/ecam/nen021
Original Article

Soybeans Ameliolate Diabetic Nephropathy in Rats

1Department of Family Medicine, Ilsan Medical Insurance Hospital, Republic of Korea
2Department of Anatomy & Brain Research Institute, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
3Department of Anatomy, Konkuk University College of Medicine, Seoul, Republic of Korea
4Department of Family Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea

Received 5 February 2007; Accepted 21 February 2008

Copyright © 2010 Young Eun Choi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Diabetic nephropathy is one of the most frequent and serious complications of diabetes mellitus. Soybeans have been shown to reduce urinary albumin excretion and total cholesterol in non-diabetic patients with nephrotic syndrome. However, reports focusing specifically on diabetic nephropathy are scarce and the available results are inconsistent. It was reported that soybean consumption reduced urinary protein excretion in type 1 diabetic patients with diabetic nephropathy, whereas it was found to elicit an increase in urinary protein excretion when soybeans were consumed by type 2 diabetic patients. This study aims to investigate the effects of soybean in diabetic nephropathy, particularly the effects of consuming soybeans on the histopathology of diabetic nephropathy, using aquaporin (AQP) and osteopontin (OPN) expression as diagnostic markers. Male Sprague-Dawley rats were assigned to one of three groups: control, diabetic with red chow diet and diabetic with soybean diet. For histological examination, the expression of OPN and AQP, renal function and hemoglobin A1c were evaluated at the end of the study. Improvements in glomerular and tubulointerstitial lesions were demonstrated in the diabetic rat group given a soybean diet. OPN and AQP expression were suppressed in the kidney specimens of diabetic rats with the soybean diet. In conclusion, soybeans may prevent the weight loss and morphological disruption of the kidney associated with diabetes mellitus. Soybeans also may improve glycemic control. It seems likely that long-term control of blood glucose levels using a soybean diet could prevent the progression of diabetes mellitus, and therefore, nephropathy could be prevented.