Objective: Rhizoma Coptidis (Coptis chinensis, Hunaglian) is most widely used Traditional Chinese Medicine (TCM) in daily life to treat inflammatory diseases and other various clinical conditions in Malaysia and China. Our aim was to evaluate in vitro cytotoxicity and in vivo acute oral toxicity of aqueous extract of Coptidis Rhizoma (AECR).

Materials and Methods: The toxicology profile includes in vivo acute oral toxicity study and in vitro cytotoxicity against non-cancerous human embryonic hepatic cell lines (WRL68 cells). The in vivo study aims to test the acute toxicity in Wistar rats with a fixed oral dose of 2,000 mg/kg for 14 days. Signs of acute oral toxicity in terms of behavior changes and mortality were noted for few hours till 14 days. Concurrently, the in vitro cytotoxicity, cell cycle arrest and apoptosis induction assays were performed against WRL68 cells using, MTS cell viability and flow cytometry assays, respectively.

Results: In acute oral toxicity study, there was no lethality and acute toxic signs were observed up to 2,000 mg/kg b.w. for the 14 days of observed duration. However, AECR demonstrated low level of in vitro cytotoxicity (IC₅₀= 7.167 ± 2.57 µg/ml) and moderate apoptosis inducing effect (p<0.05) against WRL68 cell lines. AECR was found to be nontoxic when acute oral toxicity study was performed. Nevertheless, in vitro biological activities suggested that the AECR has potential apoptosis inducing properties

Conclusions: The results of the present study suggest that the C. chinensis’s aqueous extract may possess the efficacy to develop new drugs for cancer chemotherapy. However, additional molecular studies to understand the genes associated with AECR induced apoptosis and cell cycle arrest are warranted. Furthermore, long-term in vivo toxicological evaluations should be undertaken to assess a safe dosage from the plant's potentially toxic effects.