Table 2. Comparison of hydroxyl radical scavenging activities of fingerroot

Samples	Scavenging activity1) (%)					IC50(μg/mL)
	200 μg/mL	100 μg/mL	50 μg/mL	25 μg/mL	12.5 μg/mL
80% MeOH ext.	73.2±0.8a	59.0±0.7b	38.5±1.3c	13.7±1.4e	5.6±1.3f	82.3±2.8c
80% EtOH ext.	53.9±1.1b	31.2±1.3c	7.8±2.4e	5.1±1.1f	1.1±0.8f	179.0±1.2b
80% Acetone ext.	63.9±2.1a	48.0±0.9b	20.1±0.4d	5.8±1.4f	1.0±1.7f	123.4±1.3b
Hot water ext.	22.8±1.7d	11.7±1.8e	5.5±0.9e	1.4±1.9f	0.7±0.1f	>400a
(+)-Catechin2)	88.1±2.1a	72.3±1.1a	62.3±1.9b	40.5±1.5c	31.1±1.3d	33.1±1.1c

Scavenging activities are expressed as the means±SD of triplicate experiments. Different letters (a-f) within the same column indicate significant differences (p<0.05).
(+)-Catechin was used as a positive control.