Effect of Ethanol/Water Solvents on Phenolic Profiles and Antioxidant Properties of Beijing Propolis Extracts

Table 4

Antioxidant properties of different propolis extracts.

Samples	DPPH	ABTS	FRAP	ORAC	CAA
	IC50 (μg/mL)	IC50 (μg/mL)	μg Trolox/mg	μmol Trolox/10 g	IC50 (μg/mL)
Trolox	90 ± 2	78 ± 1	1000	400
WEP	13798 ± 641	10310 ± 477	20 ± 3	1385 ± 96	25738 ± 2269
25% EEP	7129 ± 1950	5520 ± 181	16 ± 0	9180 ± 179	9907 ± 904
50% EEP	759 ± 28	613 ± 24	214 ± 9	241893 ± 13908	214 ± 29
75% EEP	633 ± 27	520 ± 13	233 ± 11	275954 ± 11336	171 ± 18
95% EEP	705 ± 21	547 ± 14	192 ± 21	143372 ± 12090	192 ± 21
100% EEP	695 ± 22	556 ± 13	194 ± 21	174593 ± 13340	243 ± 30

Note: dates are mean ± standard deviation (). Values in the same column followed by the same lowercased letter are not significantly different by Duncan’s Multiple-Range Test (). DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2-azobis (2-amidinopropane) dihydrochloride) were both expressed as IC₅₀ (concentration of total phenolics able to scavenger 50% of free radicals); ferric reducing/antioxidant power (FRAP) assay was expressed as microgram of Trolox equivalents per milligram of propolis (mg Trolox/mg); oxygen radical absorbance capacity (ORAC) was expressed as micromoles of Trolox equivalents per 100 g propolis (μmol Trolox/100 g) and cell antioxidant activity (CAA) was expressed as IC₅₀.