Systematic review of the renal protective effect of Astragalus membranaceus (root) on diabetic nephropathy in animal models

Goals: Diabetic nephropathy (DN) has long been recognized as the leading cause of end-stage renal disease. Recent experimental studies have shown that Astragalus membranaceus (AM) (root) has an inhibitory effect on the oxidative stress that characterizes early DN. This systematic review assesses the efficacy and safety of AM (root), used as a single herb, in slowing the progression of DN in diabetic rat models. Methods: We conducted both an electronic search and a search by hand of randomized, controlled AM (root) treatment studies (including its effective components) focusing on animal models of DN. Two reviewers independently selected and assessed the studies. Results: Among the 41 articles identified, 13 reports that fulfilled the inclusion criteria were included. Significant beneficial effects were observed in the AM (root) treated groups compared to controls regarding fasting blood glucose levels (standardized mean difference [SMD]: -2.86, 95% confidential interval (CI): -4.26,-1.46, P < 0.001), glomerular filtration rate (SMD: -3.36,95% CI: -4.69,-2.03, P<0.00001), urinary albumin excretion rate (SMD: -2.46, 95% CI: -3.75, -1.16, P=0.0002), and thickness of the glomerular basement membrane (SMD: -3.51, 95% CI: -6.68, -0.34, P=0.03). Conclusions: AM (root) and its effective components are effective in reducing fasting blood glucose and albuminuria levels, in reversing the glomerular hyperfiltration state, and in ameliorating the pathological changes of early DN in rat models. (C) 2009 Elsevier Ireland Ltd. All rights reserved.