In vitro evaluation of the cytotoxic potential of Brickellia cavanillesi (Asteraceae) using HepG2 cells

Characterization of the potential toxicity and biological mechanisms of alternative herbal medicine offer significant benefits for people using them to treat chronic diseases or symptoms. The Latin American tea "prodigiosa" (Brickellia cavanillesi), a member of the Asteraceae botanical family is traditionally consumed as an herbal remedy to treat diabetes and other chronic diseases in several underdeveloped countries. However, there is limited data on the potential toxicity or mechanism of action for B. cavanillesi.

Consequently, in this study we used an in vitro cell culture approach to evaluate cellular toxicity of an aqueous extract of B. cavanillesi. Hepatocellular carcinoma cells (HepG2) were submitted to both a dose- (IC50) and a time-dependent toxicity evaluation in the presence or absence of Fetal Bovine Serum (FBS). Herbal extracts (1-35%) were used for the IC50 study. In the time course study, cells were exposed to 1-10% extract solutions of B. cavanillesi for 48hrs. Cell viability was determined with the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. No significant differences were observed when cells were cultured with or without FBS. In this study the IC50 ranged from 5-10% in the absence and presence of FBS. At doses exceeding 10%, cellular viability decreased significantly (p