ABSTRACT
<p><b>OBJECTIVE</b>The decoction of Astragali Radix and Angelicae Sinensis Radix (A&A) has shown antifibrotic effects in rats with unilateral ureteral obstruction (UUO). The aim of this study was to track the effective parts of A&A for its renoprotective effects, according to the improvement of renal function and renal tubulointerstitial damage.</p><p><b>METHOD</b>A&A was sequentially extracted by using different solvents for three times and eleven different parts were gained. Wistar rats were randomly divided into Sham, UUO and the treatment groups with A&A or each part of A&A. After administration of A&A or its parts for 10 days, the levels of serum creatinin (Scr) and urea were measured. The morphological changes of kidneys were also semi-quantitatively analyzed by HE, Masson stained tissue sections, which including interstitial cell infiltration, tubular atrophy and interstitial fibrosis.</p><p><b>RESULT</b>The levels of Scr, urea were significantly increased, accompanied with severe renal damage in rats with UUO. As same as A&A, the part I in the first extraction and part IC in the second extraction were all shown to decrease the levels of Scr and urea and the index of renal interstitial damage. However, the following 4 parts extracted from IC in the third extraction were shown no effect on the above indexes.</p><p><b>CONCLUSION</b>The extract part I and part IC could be considered as the predominant parts of A&A for its renoprotective effects, due to their improvement of renal damage in interstitial nephropathy.</p>