ABSTRACT
<p><b>OBJECTIVE</b>Shen Yan Ling Tablet is an innovative compound of traditional Chinese medicine, scientifically prepared with Tripterygium wilfordii, Radix Astragali, and others, with precise efficacy on renal diseases and reduced adverse effects of Tripterygium wilfordii. Based on the Guiding Principles for New Drug Toxicity Research Before Clinical Application, we investigated the long-term toxicity of Shen Yan Ling Tablet and its effect on the reproductive function in rats.</p><p><b>METHODS</b>According to the clinical therapeutic dose and the results of the acute toxicity test of Shen Yan Ling Tablet, we equally divided 80 rats (males and females half-and-half) into a low-dose (1.25 g/kg body wt), a medium-dose (2.50 g/kg body wt), a high-dose (5.00 g/kg body wt) and a control group. After a 3-month medication, we conducted standardized long-term toxicity tests and observed the effects of Shen Yan Ling on the serum sexual hormones and epididymal sperm count.</p><p><b>RESULTS</b>After 3 months of treatment with Shen Yan Ling, no death occurred, the general status remained unchanged, and the parameters of blood cytology and biochemistry fluctuated within the normal range, without any significant changes (P > 0.05). Some blood parameters, RBC, WBC, HGB, AST and TBIL, showed statistic changes (P < 0.05), but with no clinical significance. There were no significant differences in the mass coefficients of the main organs between the medication and control groups. The high-dose group exhibited slight hepatic and pulmonary pathological changes and significantly reduced sperm counts in the epididymis, but no significant changes in serum sexual hormones (P < 0.05).</p><p><b>CONCLUSION</b>Three-month medication of Shen Yan Ling at 1.25 - 5.00 g/kg produced no significant accumulated toxicity on rats, but it had a negative effect on their reproductive function at a higher dose of > or = 5.00 g/kg.</p>