Table 4 Ferric reducing antioxidant power (FRAP) of extracts from Stachys sieboldii Miq. (FeSO₄ 7H₂O eq μM)

Extraction solvent	Concentration (μg/mL)
	500	1,000	2,000
	Water	2.70±0.221)a2)A3)	10.82±1.02aB	27.97±0.42aC
Ethanol	44.86±0.62dA	92.97±0.74dB	184.03±0.82dC
Butanol	89.25±0.83eA	188.48±1.48eB	322.90±0.24eC
Chloroform	13.14±0.31bA	31.76±1.07bB	56.00±1.09bC
Hexane	15.00±0.26cA	36.38±0.58cB	63.98±0.69cC

All values are mean SD (n=3).
^a-dMeans with different superscript small letters within the same concentration are significantly different by Duncan’s multiple range test (p<0.05).
^A-CMeans with different superscript capital letters within the same extraction solvent are significantly different by Duncan’s multiple range test (p<0.05).