Table 2. Antioxidant activity of bitter melon extracts obtained by various extraction methods

Extraction method	IC₅₀ value (mg/mL)
	ABTS radical scavenging activity	Hydroxyl radical scavenging activity	Reducing power	Fe²⁺ chelating ability
PUE-E³⁾	0.52±0.02^1)a2)	1.94±0.02^a	1.23±0.03^a	1.35±0.02^a
PUE-W	0.75±0.05^bc	2.51±0.07^b	1.61±0.06^b	2.71±0.25^c
BUE-E	0.64±0.04^ab	2.51±0.09^b	1.33±0.03^a	2.26±0.15^b
AE-W	0.82±0.05^c	2.90±0.19^c	2.22±0.04^d	4.81±0.16^d
EE	0.54±0.02^a	2.21±0.07^ab	1.96±0.04^c	1.53±0.18^a
HWE	1.85±0.13^d	3.16±0.08^c	3.17±0.31^e	5.85±0.24^e

Results are mean and standard deviation (n=3).
Values with different letters in the same column are significantly different at p<0.05 by Duncan’s multiple range test.
PUE-E, probe type-ultrasonic assisted extraction with 60% ethanol; PUE-W, probe type-ultrasonic assisted extraction with water; BUE-E, bath type-ultrasonic assisted extraction with 60% ethanol; AW-E, autoclave extraction with water; EE, 60% ethanol extraction; HWE, hot water extraction.