Purpose: To determine the phenolic constituents as well as anti-proliferative, antioxidant and iron-chelating activities of the leaf and rhizome extracts of Phymatopteris triloba.

Methods: Concentrations of selected hydroxybenzoic acids, hydroxycinnamic acids and flavonoids in aqueous extracts were quantified using high performance liquid chromatography (HPLC). Anti-proliferative activity was assessed on human cervix cancer cell line (HeLa) and human chronic myelogenous leukemia cell line (K562). Superoxide and nitric oxide scavenging activities as well as iron-chelating activity were determined colorimetrically.

Results: Protocatechuic acid content of the rhizome extract (154.7 mg/g dry matter (DM)) was 1.9-fold higher than in the leaf extract. p-Hydroxybenzoic acid (34.6 mg/g DM) and gallic acid (18.9 mg/g DM), were only detected in the rhizome extract. Sinapic acid (6.6 mg/g DM) was detected in the leaf extract only. Myricetin content of leaf extract (98.5 mg/g DM) was 3.7-fold higher compared with the rhizome extract. At 500 mg DM/ml, both extracts produced about 40 and 30 % anti-proliferative activity on HeLa cells and K562 cells, respectively. Both extracts had moderate nitric oxide-scavenging and iron-chelating activities. The leaf extract half-maximal effective concentration (EC₅₀) value of 0.85 mg/ml (scavenging of superoxide radicals) was higher than that of ascorbic acid.

Conclusion: P. triloba is a potential source of anti-proliferative, antioxidant and iron-chelating agents. Its bioactivities may be attributed to the presence of phenolic constituents.