Aerva lanata (Polpala): Its effects on the structure and function of the urinary tract

CONTEXT: Aerva lanata is not prescribed for long-term use in Ayurveda as it is believed to produce structural changes in the urinary tract of the patients leading to renal failure. AIM: To investigate the toxic effects of Aerva lanata on the structure and function of urinary tract of a rat model (Sprague-Dawley rats). SETTINGS AND DESIGN: An experimental study. Thirty male and thirty female healthy rats were randomly assigned to three groups (test groups 1, 2 and control) and administered dried infusion of A. lanata 25g/200ml (low dose), 100g/200ml (high dose) and distilled water respectively, for 30 days. MATERIALS AND METHODS: Blood and urine were collected and creatinine was measured. Creatinine clearance (Ccr) and urine flow rate (UFR) of rats were determined to assess renal function. Kidneys, ureters, and bladders of rats were harvested for light microscopic (LM) studies. Electron microscopic (EM) studies were done on kidney tissues. STATISTICAL ANALYSIS USED: Difference in mean values of Ccr and UFR between test groups and the control group were compared statistically using independent T test. LM and EM findings of the two treated groups (T1 and T2) were statistically compared with the control group (C) using standard normal distribution. RESULTS: Ccr and UFR of test groups were not significantly different from that of the control group. LM studies did not show any histological changes suggesting toxicity. EM, however showed significant ultra structural changes in proximal convoluted tubular epithelial cells of rats in the two test groups. CONCLUSION: Administration of dried Aerva lanata for a period of one month did not produce significant effects on renal function of rats. However administration for the same period caused significant ultra structural changes in the proximal convoluted tubular epithelial cells.