Quality and Antioxidant Activity of 10 Polygonaceae Plant Seed

Background: This study aimed to explore natural antioxidants of plant origin by evaluating the antioxidant activity of seed extracts from Polygonaceae species. Methods and Results: The seeds used in the experiment had a filled-seed percentage of at least 89% and a germination rate exceeding 50%. The total phenolic content was highest in Rumex crispus (10.8 ㎎ GAEs/g seed), followed by Rumex obtusifolius (8.3 ㎎ GAEs/g seed). The total flavonoid content was highest in Reynoutria sachalinensis (1.7 ㎎ QEs/g seed), followed by Persicaria sagittata (1.5 ㎎ QEs/g seed). The DPPH radical scavenging activity, based on EC₅₀ values, was highest in Rumex crispus (5.5 ㎍/㎖) and Rumex obtusifolius (7.5 ㎍/㎖). The ABTS radical scavenging activity, also based on EC₅₀ values, was highest in Rumex crispus (1.5 ㎍/㎖) and Rumex obtusifolius (2.0 ㎍/㎖). In the FRAP assay, Rumex crispus (9118.0 μM Fe(II)/g extract) and Rumex obtusifolius (7334.4 μM Fe(II)/g extract) exhibited the highest antioxidant capacities. Based on hierarchical clustering analysis of antioxidant activities, the ten species were classified into three groups, ranging from low (Group 1) to high (Group 3) activity. Conclusions: Rumex crispus and Rumex obtusifolius were classified into Group 3, demonstrating the highest antioxidant potential.