Evaluation of Aldose Reductase, Protein Glycation, and Antioxidant Inhibitory Activities of Bioactive Flavonoids in Matricaria recutita L. and Their Structure-Activity Relationship

Table 2

Inhibitory activities of compounds isolated from Matricaria recutita L. on rat lens aldose reductase (RLAR), DPPH radical scavenging, and advanced glycation end products (AGEs).

Compounds	IC50 (μM)^1)
	RLAR	DPPH	AGEs
Agipenin-7-O-β-D-glucoside (1)	4.25 ± 0.07^d	>25.0	NI
Luteolin-7-O-β-D-glucoside (2)	1.12 ± 0.02^b	7.24 ± 0.38^b	NI
Penduletin (3)	NI^2)	NI	NI
Jaceidin (4)	NI	NI	NI
Agipenin-7-O-β-D-glucuronide (5)	1.16 ± 0.04^b	10.58 ± 0.47^bc	NI
Luteolin-7-O-β-D-glucuronide (6)	0.85 ± 0.02^a	8.92 ± 0.21^b	3.39 ± 0.17^a
3,5-O-di-caffeoylquinic acid (7)	0.72 ± 0.02^a	12.34 ± 0.63^bc	NI
6-Hydroxyapigenin (8)	NI	NI	NI
Apigenin (9)	1.72 ± 0.04^c	15.63 ± 0.34^c	NI
Luteolin (10)	1.42 ± 0.03^bc	11.53 ± 0.38^bc	6.01 ± 0.38^b
Quercetin^3)	1.21 ± 0.04^b	—	—
L-Ascorbic acid^4)	—	3.75 ± 0.17^a	—
Aminoguanidine^5)	—	—	98.69 ± 5.31^c

¹⁾The IC₅₀ values are defined as standard derivation (RSD) of half-maximal inhibitory concentrations obtained from three independent experiments performed in duplicate and the range of the inhibitor concentrations adopted to evaluate IC₅₀ was prepared as follows: (1) RLAR: 1, 5, and 10 μg/mL; (2) DPPH: 15, 30, and 75 μg/mL; and (3) AGEs: 10, 25, and 50 μg/mL. ²⁾NI: no inhibition. ^3)–5)Quercetin, L-ascorbic acid, and aminoguanidine are the positive control for RLAR inhibition, DPPH scavenging, and AGEs inhibition. Values within a column marked with different letters are significantly different from each other ().