[The protective effects of three components isolated from Astragalus membranaceus on shock wave lithotripsy induced kidney injury in rabbit model].

OBJECTIVE

Extracorporeal shock wave lithotripsy (ESWL) is has been shown to reduce renal parenchymal injury subject to application of shock wave lithotripsy in our pervious study. To investigate the protective action of three main components from Astragalus membranaceus, including total saponins of astragalus (TSA), total flavonoids of astragalus (TFA) total polysaccharide of astragalus (TPA) in alleviating shock wave induced kidney damage.

METHODS

Sixty four male rabbits were randomly assigned to a control group or to 3 groups that were premedicated with TSA TFA and TPA respectively prior to application of ESWL. Each group of animals underwent shock wave lithotripsy (18 kV) to the right kidneys and received a total of 1500 shocks. Peripheral blood samples were collected to evaluate the levels of plasma endothelin-1 (ET-1), plasma nitric oxide (NO) and serum malondialdehyde (MDA) before and after shock wave treatment. The concentrations of these markers in the treated kidney tissues were also detected 3 days, 7 days and 14 days after application of ESWL. The changes of histopathology and cells ultrastructure were observed through light microscope and electron microscope. Untreated contralateral kidneys were evaluated as controls.

RESULTS

In control serials the levels of ET-1 and MDA were elevated significantly while the level of NO was significantly decreased after application of shock wave lithotripsy (P < 0.05). The comparison between the controls and premedicated groups demonstrated that all these three components especially TSA and TFA significantly inhibited shock wave induced increasing of ET-1 and MDA (P < 0.05). TSA also significantly suppressed the decrease of NO and made the recovery time earlier compare to the results of controls (P < 0.05). However, TFA and TPA had almost no effects on the change of NO. (P > 0.05). The results in histopathology showed noticeably damage of glomerular and tubular epithelial cells in the treated kidneys in the controls. The histological alterations in the TPA group were similar to those of the controls. These alterations were significantly milder in the TSA and TFA particular the TSA group.

CONCLUSION

TFA and TSA, especially TSA seemed to play the key role in alleviating ESWL induced kidney damage.