Toxicological safety evaluation of zengye granule through acute and 30-day toxicity studies in rats

Ethnopharmacological relevance: Zengye granule (ZYG), a traditional Chinese medicine formula composed of Radix Scrophulariae, Radix Ophiopogonis, and Radix Rehmanniae in the ratio of 1.0:0.8:0.8, is listed in the Chinese Pharmacopoeia for treating diseases associated with yin deficiency, such as inner heat, dry mouth and pharynx, and dry bound stool. However, little information is available on its toxicological safety.Aim of the study: To evaluate the acute and subacute toxicity of ZYG after oral administration in rats. Materials and methods: In the acute toxicity study, ZYG was orally administered to rats at a single dose of 10 g/kg/ day. In the subacute toxicity study, ZYG was administered orally to rats at repeated daily doses of 2.5, 5.0, or 10 g/kg/day for 30 days. The toxicological effects were evaluated by assessing the rats' general behavior, body weight, food intake, water consumption, blood biochemical and hematological parameters, organ coefficients, and organ histopathology.Results: No obvious adverse reactions were found in the rats in the acute toxicity study, indicating that ZYG was non-toxic. In the subacute toxicity study, ZYG had no toxic effect on the rats at a dose of 2.5 g/kg/day but showed slight toxicity in the kidneys, and spleens of the rats at doses of 5 and 10 g/kg/day. Significant drug toxicity was observed in male and female rats at 5 and 10/kg/day; however, elevated WBCs counts, ALT, and LYMs levels were found in female rats.Conclusions: The oral administration of ZYG at a dose of less than 10 g/kg/day for 1 day or 2.5 g/kg/day for 30 consecutive days can be considered safe, as these doses showed no distinct toxicity or side effects in the rats in this study. Therefore, the dosage should be set according to the clinically recommended dosage to ensure its safety.