Renal toxicity of slimming herbs (Aristolochia fangchi) containing aristolochic acid in rats

Abstract

Introduction Aristolochic acid (AA) is a potent nephrotoxic and carcinogenic in both animals and humans. The present study supported the evidence that AA is nephrotoxic and recovery can be achieved after stopping the intake of slimming pills containing this chemical. Aim The present study aimed to show that natural products are not without risk and prompts nephrologists to investigate this possibility when faced with renal disease of unknown origin. Materials and methods Forty adult female albino rats were divided into four groups: the control group and three experimental groups. The control group received normal saline intraperitoneally, and the three experimental groups (1AA+1AAR, 2AA+2AAR, and 3AA+3AAR (Aristolochic Acid Recovery); each comprising 10 rats) received AA intraperitoneally (0.1 mg/kg) for 7, 14, and 35 days, respectively. At the end of each treatment period, five rats were sacrificed and five other rats represented the recovery groups. At the time of sacrifice the rats were anesthetized, and blood samples were taken for measuring kidney functions. Specimens from the right kidney of each rat were taken for light and electron microscopic examination. Results Light microscopic changes were congestion of glomerular capillaries, degeneration of proximal tubules, and increased deposition of collagen fibers around Bowman’s basement membrane and the basement membranes of proximal and distal tubules. The medulla showed hyalinization of collecting tubules, congestion of vasa recta, and inflammatory cells infiltration. Ultrastructural observations were fusion of podocytes, damaged mitochondria of proximal tubules, and destruction of its basolateral infoldings. Conclusion Our results strongly demonstrate that pure AA, which has been identified in slimming Chinese herb mixtures used in weight-reducing pills, is nephrotoxic.