Evaluation of the acute and sub-chronic oral toxicity of the herbal formula Xiaoer Chaigui Tuire Oral Liquid

Abstract

Ethnopharmacological relevanceXiaoer Chaigui Tuire Oral Liquid (XCTOL) is a popular Chinese herbal formula. It is used to treat exogenous fever in children by inducing diaphoresis and clearing interior heat. Aim of the studyTo evaluate the acute and sub-chronic toxicity of XCTOL in mice and rats, respectively. Materials and methodsIn the acute toxicity study, mice were orally administered 100g/kg body weight XCTOL three times a day. General behavior, adverse effects and mortality were recorded for 14 days after treatment. In the sub-chronic toxicity study, rats were orally administered 0, 20 or 80g/kg XCTOL for 30 days. The rats were observed daily for clinical signs and mortality. Body weight changes were measured every three days, and relative organ weights, hematological parameters, urinalysis results, biochemical parameters and pathology were monitored at the end of treatment. After treatment, a 30-day withdrawal study was conducted. ResultsIn the acute toxicity study, after the mice were administered with 300g/kg (3×100g/kg) XCTOL in the first day, no adverse effects or death were observed in the following 14 days. In the 30-day sub-chronic toxicity study, daily oral administration of 80g/kg XCTOL resulted in significant body weight loss in both male and female rats. In the male rats, the red blood cell distribution width standard deviation (RDW-SD) and red blood cell distribution width coefficient of variability (RDW-CV) in the hematological test and total bilirubin (T-Bil) in the blood biochemistry test were significantly increased (RDW-SD, p<0.01; RDW-CV and T-Bil, p<0.05 vs. the control group). In the female rats, the specific gravity of the urinalysis was significantly increased (p<0.05 vs. the control group). Pathological damage was not observed in the main organs in the 80g/kg group. In the 20g/kg group, the lymphocyte % (LYM%) was significantly increased (p<0.05 the control group) in the female rats. ConclusionsThe maximum-tolerated dose of XCTOL was greater than 300g/kg in mice. The no-observed-adverse-effect-level was between 20 and 80g/kg body weight for 30 days in rats, which is 2.2–8.8 times higher, respectively, than the dose that has already been used in the clinical practice. Therefore, XCTOL at a dose less than 300g/kg in one day or 20g/kg per day for 30 days is considered safe.