Acute and a 28-day repeated-dose toxicity study of total flavonoids from Clinopodium chinense (Benth.) O. Ktze in mice and rats.

Clinopodium chinense (Benth.) O. Ktze (Labiatae), known as 'Duanxueliu' in the Chinese Pharmacopoeia, has been widely used as a traditional Chinese medicine for the treatment of hemorrhagic disease. Total flavonoids from Clinopodium chinense (Benth.) O. Ktze (TFCC), the most active ingredient, possess a variety of properties, such as antioxygenation. Until now, evidence-based toxicity data on TFCC has been limited. This study evaluated the acute (in mice and rat) and the 28-day repeated-dose (in rat) toxicity study of TFCC, respectively. In acute study, oral administration of TFCC to rats and mice did not induce toxicity or mortality up to the maximum doses of 4000 and 5000 mg/kg, respectively. In subacute toxicity study, we administered TFCC at daily doses of 70, 210, and 630 mg/kg for 4 consecutive weeks to rats via gavage. We observed no changes in food consumption, water intake, body weight, chemistry and hematological parameters, organ weight, gross pathology or histopathology. No animals from any group died. These findings indicate that TFCC is relatively nontoxic, and provide practical guidance for selecting a safe dose for further investigation of TFCC in animal studies or clinical trials.