Phenol profiles and antioxidant capacities of Bistort Rhizoma (Polygonum bistorta L.) extracts

Abstract

Bistort Rhizoma (BR) is consumed as a traditional medicinal herb in China, but there reports on its bioactive components are scarce. In the present study, a fingerprinting analysis was built in 35 batches of BR from various sources, and five major compounds, the content of total phenols (TP) as well as total extractable tannins (TET) were measured. The antioxidant properties were examined by three methods, and then the correlation coefficients between antioxidant activity and content of BR properties were evaluated. The results showed that the content of TP was significantly correlated with the herbal antioxidant activity (R² = 0.5501 in the DPPH assay; R² = 0.6387 in the ABTS assay and R² = 0.6722 in the FRAP assay) but the five major components are not, TET also partly influenced the herbal efficiency. In conclusion, the properties responsible for the antioxidant activity of BR are phenols, and the active constituents may be some trace phenols in BR, which need further study to unravel the truly active compounds.