Table 2.

Antioxidant and antidiabetic activity of the 70% ethanol and water extracts from onion (mean ± SEM, n = 3)

Samples	IC50 (μg/ml, Mean ± SEM)a
	DPPH	ABTS	PTP1B	α‐Glucosidase	AGEs
70% EtOH extracts
Red onion	10.60 ± 0.18e	7.00 ± 0.20d	0.76 ± 0.17c	5.76 ± 0.03bc	12.79 ± 0.22b
Yellow onion	4.50 ± 0.06c	6.64 ± 0.03c	0.86 ± 0.04c	3.90 ± 0.08b	12.25 ± 1.35b
Water extracts
Red onion	9.86 ± 1.40e	29.04 ± 0.11f	0.33 ± 0.01b	8.99 ± 0.56c	51.91 ± 1.53d
Yellow onion	6.77 ± 1.27d	12.03 ± 0.23e	0.30 ± 0.08b	5.44 ± 0.06bc	25.17 ± 1.75c
Positive controls
Ascorbic acid	1.27 ± 0.01b
Trolox		2.76 ± 0.05b
Ursolic acid			3.40 ± 0.34d
Acarbose				70.17 ± 4.96d
Aminoguanidine					58.47 ± 0.17e

^aThe 50% inhibitory concentration (IC₅₀) values (μg/ml) were calculated from a log dose concentration–inhibition curve and expressed as mean ± SEM of triplicate experiments.

Mean with different superscripts letters (b–f) are significantly different with Duncan's test at p < 0.05.