The flower of Trollius chinensis Bunge (Flos trollii) is used for treating upper respiratory infections, pharyngitis, tonsillitis and bronchitis as a Chinese folk medicine since ancient times. This study aimed to investigate possible antioxidant and anticancer activity of methanolic extract of F. trollii (FTME). The antioxidant activity of FTME was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, hydroxyl radical scavenging assay and metal chelating assay. FTME exhibited a powerful free radical scavenging activity against DPPH and acted as a strong hydroxyl radical scavenger to prevent deoxyribose degradation in Fe³⁺/ascorbate/ethylenediaminetetraacetic acid (EDTA)/H₂O₂ system. In addition, FTME also showed a weak metal chelating activity. Anticancer activity of FTME was determined by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. FTME showed strong anticancer activities in antiproliferative activities against human gastric (AGS), A375SM, MCF-7, and MDA-MB-231 cancer cell lines. The half-inhibitory concentrations (IC₅₀) for these cancer cells were 143.72, 62.23, 244.50 and 279.06 μg/ml, respectively. All results suggest that F. trollii is a powerful natural antioxidant, and also exert stronger anticancer activities for four kinds of human cancer cell lines. It could be a potential source of natural antioxidant and also as a health food.

Key words: Trollius chinensis Bunge, antioxidant, anticancer activity.