Toxicological evaluation of aqueous extract of the traditional Chinese formula Qing Hao Gan Cao

(QHGC), a Chinese medicinal formula containing and , has been used to treat sunstroke and as an antiviral agent for more than 800 years. It has not previously been subject to a toxicological safety evaluation in acute and subacute (28 days) studies. Therefore, the acute and subacute toxicity of an aqueous extract of QHGC were evaluated . For the QHGC preparation, the botanical raw materials were crushed into pieces and mixed in the ratio of 10:1 in distilled water for 12 h, then boiling three times for 2 h each time. The three decoctions were mixed and filtered, then spray-dried with hot air at 160°C for 30 min, and stored at room temperature. For the acute toxicity test, 72.0 g/kg of QHGC extract was administered by gavage to male and female mice. Body weight, general observations, and autopsy results were recorded. No mortality or toxicity signs were observed during the studies. For the subacute toxicity test, 4.0, 8.0, or 16.0 g/kg/day of QHGC extract was administered to rats for 28 days. General observations and mortality, body weight, biochemical and hematological parameters, organ weight, and pathological morphology were analyzed. The acute and subacute toxicity studies did not show significant changes in body weight, general observations, hematology and biochemical parameters, organ weight, and liver, spleen, stomach, duodenum, testis, ovary, lung, heart, and kidney histopathological analyses. The consumption of QHGC aqueous extract can be considered safe within the conditions of this study.