Chemical characterization, antioxidant properties, anti-inflammatory activity, and enzyme inhibition of Ipomoea batatas L. leaf extracts

Figures & data

Figure 1. (A) Chlorogenic acid docked in the α-glucosidase active site and (B) the relevant interactions found for the best-ranked position.

Table 1. Phenolic compounds of I. batatas leaf extracts (µg/mg extract)*.

		Extraction technique
No	Compounds	Soxhlet	Decoction	MW
1	Gallic acid	nd	nd	nd
2	Catechin	3.26 ± 0.33	1.44 ± 0.15	1.08 ± 0.11
3	Chlorogenic acid	100.82 ± 9.7	97.80 ± 9.8	4.43 ± 0.56
4	p-OH benzoic acid	0.88 ± 0.09	0.43 ± 0.04	0.18 ± 0.03
5	Vanillic acid	0.85 ± 0.08	0.71 ± 0.08	0.41 ± 0.04
6	Epicatechin	2.92 ± 0.29	3.11 ± 0.31	0.32 ± 0.03
7	Syringic acid	nd	nd	nd
8	3-OH benzoic acid	0.33 ± 0.03	nd	nd
9	3-OH-4-MeO benzaldehyde	nd	0.14 ± 0.02	0.07 ± 0.01
10	p-Coumaric acid	0.11 ± 0.01	nd	nd
11	Rutin	nd	0.25 ± 0.04	nd
12	Sinapic acid	0.07 ± 0.01	nd	nd
13	t-Ferulic acid	1.39 ± 0.14	0.93 ± 0.08	0.21 ± 0.04
14	Naringin	0.70 ± 0.09	2.25 ± 0.23	0.45 ± 0.09
15	2,3-diMeO benzoic acid	8.49 ± 0.75	15.18 ± 1.61	0.87 ± 0.11
16	Benzoic acid	nd	0.82 ± 0.19	0.15 ± 0.02
17	o-Coumaric acid	8.50 ± 0.81	5.49 ± 0.74	0.29 ± 0.04
18	Quercetin	0.11 ± 0.01	nd	nd
19	t-Cinnamic acid	nd	nd	0.46 ± 0.11
20	Naringenin	0.14 ± 0.01	nd	nd

nd: not detected; *values expressed are means ± SDs.

Table 2. Antioxidant properties of I. batatas leaf extracts*.

Samples	Total phenolic content (mgGAEs/g extract)	Total flavonoid content (mgREs/g extract)	DPPH (mmolTEs/g extract)	ABTS (mmolTEs/g extract)	CUPRAC (mmolTEs/g extract)	FRAP (mmolTEs/g extract)
Ipomoea (Soxhlet)	77.39 ± 0.99^b	25.33 ± 0.77^a	0.93 ± 0.03^b	0.96 ± 0.02^b	2.19 ± 0.04^c	0.87 ± 0.03^c
Ipomoea (MW)	73.10 ± 3.75^c	7.74 ± 0.25^c	0.69 ± 0.02^c	0.78 ± 0.05^c	2.68 ± 0.03^b	0.91 ± 0.01^b
Ipomoea (decoction)	89.26 ± 1.34^a	17.71 ± 2.31^b	2.84 ± 0.03^a	3.05 ± 0.02^a	5.32 ± 0.36^a	3.97 ± 0.10^a

GAEs: gallic acid equivalents; REs: rutin equivalents; TEs: trolox equivalents. *Data from three repetitions with mean ± SD; means with different superscript letters (a, b and c) in the same column were significantly different (ANOVA, p < 0.05).

Table 3. Enzyme inhibitory effects of I. batatas extracts*.

Samples	AChE Inhibition (mgGALAE/g extract)	BChE Inhibition (mgGALAE/g extract)	α-Amylase Inhibition (mmolACAE/g extract)	α-Glucosidase Inhibition (mmolACAE/g extract)	Tyrosinase Inhibition(mgKAE/g extract)
Ipomoea Soxhlet	0.71 ± 0.03^a	na	0.30 ± 0.01^a	7.12 ± 0.15^a	22.48 ± 0.55
Ipomoea MW	0.70 ± 0.03^a	na	0.22 ± 0.01^c	6.99 ± 0.09^b	na
Ipomoea decoction	0.66 ± 0.02^b	na	0.25 ± 0.01^b	6.74 ± 0.03^c	na

GALAE: galantamine equivalents; ACAE: Acarbose equivalents; KAE: kojic acid equivalents; na: not active. *Data from three repetitions with mean ± SD; means with different superscript letters (a, b and c) in the same column were significantly different (ANOVA, p < 0.05).

Figure 2. ROS level in the decoction (Dec.) extract per dose (ANOVA, p < 0.0001; ***p < 0.001 vs H₂O₂ group).

Figure 3. PGE₂ level in the decoction (Dec.) extract per dose (ANOVA, p < 0.0001; ***p < 0.001 vs H₂O₂ group).

Figure 4. (A) Nitrite level in the decoction (Dec.) extract per dose. (B) iNOS gene expression in the decoction (Dec.) extract per dose (ANOVA, p < 0.0001; *p < 0.5, **p < 0.01, ***p < 0.001 vs LPS group).