Bioactive Components from Ampelopsis japonica with Antioxidant, Anti-α-Glucosidase, and Antiacetylcholinesterase Activities

Abstract

The dried root of Ampelopsis japonica (Thunb.) Makino (A. japonica.) is a traditional medicine used to treat fever, pain, and wound healing. It exhibits anti-inflammatory, antitumor, antityrosinase, and antimelanogenic activities. In this paper, we used different solvent extracts from the root of A. japonica to determine their antioxidant activity. Acetone extract showed relatively strong antioxidant properties by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), superoxide radical scavenging activity, and ferric reducing antioxidant power (FRAP) assays. In addition, these extracts also showed significant α-glucosidase and acetylcholinesterase (AChE) inhibitory activities. Acetone extract significantly inhibited α-glucosidase with an IC50 value of 8.30 ± 0.78 μg/mL, and ethanol extract remarkably inhibited AChE with an IC50 value of 37.08 ± 7.67 μg/mL. Using HPLC analysis and comparison with the chemical composition of various solvent extracts, we isolated seven active compounds and assessed their antioxidant, anti-α-glucosidase, and anti-AChE activities. Catechin (1), gallic acid (2), kaempferol (3), quercetin (4), resveratrol (6), and epicatechin (7) were the main antioxidant components in the root of A. japonica. According to the results of DPPH, ABTS, and superoxide radical scavenging assays, these isolates showed stronger antioxidant capacity than butylated hydroxytoluene (BHT). Moreover, 1, 3, 4, euscaphic acid (5), 6, and 7 also expressed stronger anti-α-glucosidase activity than the positive control acarbose, and all the isolated compounds had a good inhibitory effect on AChE. Molecular docking models and hydrophilic interactive modes for AChE assays suggest that 1 and 5 exhibit unique anti-AChE potency. This study indicates that A. japonica and its active extracts and components may be a promising source of natural antioxidants, α-glucosidase, and AChE inhibitors.

Design of Scaffolds Based on Zinc-Modified Marine Collagen and Bilberry Leaves Extract-Loaded Silica Nanoparticles as Wound Dressings

“…The IC 50 obtained for EGCG is the equivalent of 20.13 ± 1.33 µM (9.23 ± 0.61 µg/mL). Similar results were obtained by Xu et al and Li et al 47 , 48 Other studies mentioned slightly higher values of IC 50 for EGCG, 49 , 50 however in all cases EGCG proved a three to five times better inhibition of α-glucosidase compared to acarbose, which is a standard prescribed anti-diabetic drug that inhibits α-glucosidase activity. Even though catechin derivatives are known for their inhibition of α-glucosidase, other polyphenols, like chlorogenic acid or rutin, also show inhibitory activity of α-glucosidase, 51 , 52 so these might contribute to the antidiabetic activity of the prepared WB extract as well.…”

Nomilin from Yuzu Seed Has In Vitro Antioxidant Activity and Downregulates Melanogenesis in B16F10 Melanoma Cells through the PKA/CREB Signaling Pathway

“…The ABTS stock solution was reacted with 7 mM potassium persulfate (final concentration), and the mixture was left at room temperature for 12–16 h before use to generate ABTS radicals. Radical scavenging was measured by mixing 200 µL of each sample and 1000 µL ABTS solution [ 16 ]. Mixtures were left for 15 min in the dark, and absorbance was measured at 730 nm with the SCINCO UV-Vis spectrophotometer S-3100 (Seoul, Korea).…”

Ethyl Gallate Isolated from Castanopsis cuspidata var. sieboldii Branches Inhibits Melanogenesis and Promotes Autophagy in B16F10 Cells

“…Radical scavenging activity (%) = (Abscontrol − Abssample)/Abscontrol × 100 2.4.2. Measurement of ABTS Cation Radical Scavenging Activity ABTS cation radical scavenging ability was measured using Liang et al's method, with slight modifications [17]. The reaction of an equal volume of 7 mM ABTS (2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) solution with 2.45 mM potassium persulfate in the dark for 18 h produced an ABTS cationic radical.…”