RESUMEN
<p><b>OBJECTIVE</b>To observe the effects of Fuzheng Huayu Recipe (FHR) on rat's renal interstitial fibrosis induced by mercuric chloride (HgCl2), and to explore preliminarily its mechanism of action.</p><p><b>METHODS</b>Rats were randomly divided into four groups: the normal group, the model group, the FHR group and the vitamin E group, the latter two were treated respectively by FHR 4.6 g/kg and vitamin E 100 mg/kg. Rats model was established by oral administration of 8 mg/kg HgCl2 for 9 weeks. Serum creatinine (Cr) and urea nitrogen (BUN) content were tested with corresponding test kits; hydroxyproline (Hyp) content in kidney was assayed with hydrochloric acid hydrolysis; renal histologic change was observed with HE, Masson and methenamine silver (PASM) staining; and collagen type I (Col I), as well as protein expressions of fibronectin (FN) and alpha-smooth muscle actin (alpha-SMA) was determined with Western blot.</p><p><b>RESULTS</b>Compared with the model group, the kidney/body weight ratio, serum levels of Cr and BUN, kidney Hyp content, and severity of renal interstitial fibrosis in the two treated groups were significantly lower (P<0.05 or P<0.01), and the improvements were more significant in the FHR group than those in the vitamin E group; Col I and FN protein expression was also weaker in the two treated group (Col, P<0.05; FN, P<0.01); while the expression of alpha-SMA was lower in the FHR group (P<0.01), but it wasn't in the vitamin E group (P>0.05).</p><p><b>CONCLUSION</b>FHR could improve the HgCl2-induced renal function injury in rats, decrease extracellular matrix deposition and restrain renal interstitial fibrosis, the mechanism of action might be related with its inhibitory effect on myofibroblast activation.</p>