Correlation analysis and evaluation of antioxidant activity of ethanol extracts of Leonurus japonicus Houtt.

This study evaluated the antioxidant activity of ethanol extracts from Leonurus japonicus Houtt. and its correlation with antioxidant compounds. The 80% ethanol extract exhibited the highest total phenolic content (4.36±0.12 mg GAE/g) and phosphomolybdenum activity (5.69±1.55 mg AAE/g). Conversely, the 100% extract showed the maximum total flavonoid content (1.84±0.02 mg CE/g), while the highest ferric-reducing power was observed in the 40% extract (202.13±0.12 mg TE/g). Radical scavenging activities, measured by DPPH, ABTS, and oxygen radical absorbance capacity assays, varied significantly depending on the ethanol concentration. Correlation analysis confirmed that phenolic contents are highly associated with antioxidant activities, indicating their role as major functional contributors. These findings highlight L. japonicus as a promising natural antioxidant source and provide foundational data for optimizing extraction conditions in the food and cosmetic industries.