Effect of Shenkang granules on the progression of chronic renal failure in 5/6 nephrectomized rats

Shenkang granules (SKGs) are a Chinese herbal medicinal formula, consisting of rhubarb (Rheum palmatum L.), Salvia miltiorrhiza, milkvetch root [Astragalus membranaceus (Fisch.) Bunge] and safflower (Carthamus tinctorius L.). The aim of the present study was to investigate the effect of SKG on chronic renal failure (CRF) in 5/6 nephrectomized (5/6 Nx) rats. The rats were randomly divided into seven groups (n=10 per group) as follows: (i) 5/6 Nx (model group; 2.25 ml/kg/day normal saline); (ii) SKGL (low dose; 5/6 Nx treated with 2 g crude drug/kg/day SKG); (iii) SKGM (moderate dose; 5/6 Nx treated with 4 g crude drug/kg/day SKG); (iv) SKGH (high dose; 5/6 Nx treated with 8 g crude drug/kg/day SKG); (v) benazepril treatment group (5/6 Nx treated with 5 mg/kg/day benazepril); (vi) Shenkang injection (SKI) group (5/6 Nx with 13.3 ml/kg/day SKI); and (vii) sham-operated group (2.25 ml/kg/day normal saline). After 30 days, the levels of microalbumin, total protein, serum creatinine, blood urea nitrogen and serum lipid were found to be significantly decreased in the SKGL and SKGM rats, showing histological improvement compared with the untreated 5/6 Nx rats, as determined by hematoxylin and eosin, and Masson's trichrome staining. In addition, SKG was found to significantly improve the levels of glutathione peroxidase and reduce the damage caused by free radicals to the kidney tissues. Furthermore, SKG prevented the accumulation of extracellular matrix by decreasing the expression of collagen I and III and inhibiting the expression of matrix metalloproteinases-2 and -9 in the renal tissue, as determined by western blot analysis. SKG was also shown to decrease the concentrations of serum transforming growth factor-β₁, as determined by ELISA, and kidney angiotensin II, as determined using a radioimmunoassay kit. In conclusion, SKG was demonstrated to ameliorate renal injury in a 5/6 Nx rat model of CRF. Thus, SKG may exert a good therapeutic effect on CRF.