Acetyl- and butyryl-cholinesterase inhibitory activities of the edible brown alga Eisenia bicyclis

• Published in: Archives of pharmacal research Vol. 38; no. 8; pp. 1477 - 1487
• Main Authors: Choi, Jae Sue, Haulader, Shourav, Karki, Subash, Jung, Hee Jin, Kim, Hyeung Rak, Jung, Hyun Ah
• Format: Journal Article
• Language: English
• Published: Seoul Pharmaceutical Society of Korea 01.08.2015; 대한약학회
• Subjects: 2,2-diphenyl-1-picrylhydrazyl; acetylcholinesterase; Acetylcholinesterase - metabolism; Alzheimer disease; Animals; antioxidant activity; Antioxidants - chemistry; Antioxidants - isolation & purification; Antioxidants - pharmacology; Butyrylcholinesterase - metabolism; cholinesterase; Cholinesterase Inhibitors - chemistry; Cholinesterase Inhibitors - isolation & purification; Cholinesterase Inhibitors - pharmacology; chromatography; Electrophorus; ethyl acetate; Free Radical Scavengers - chemistry; Free Radical Scavengers - isolation & purification; Free Radical Scavengers - pharmacology; Horses; inhibitory concentration 50; macroalgae; Medicine; nuclear magnetic resonance spectroscopy; Phaeophyceae; Phaeophycophyta; Pharmacology/Toxicology; Pharmacy; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; reactive oxygen species; Research Article; Seaweed; silica gel; spectral analysis; 약학; Alzheimer’s disease; Antioxidant; Acetylcholinesterase; Butyrylcholinesterase; 974-B
• ISSN: 0253-6269; 1976-3786; 1976-3786
• DOI: 10.1007/s12272-014-0515-1

As part of our ongoing isolation of cholinesterase (ChE) inhibitors from natural marine sources, the bioactivity of the ethanolic extracts from 12 Korean seaweeds were screened for their inhibitory activities against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and total reactive oxygen species (ROS) generation. Eisenia bicyclis exhibited promising inhibitory properties against AChE, BChE and total ROS with inhibition percentages (%) of 68.01 ± 1.37, 95.72 ± 3.80, and 73.20 ± 1.82 at concentrations of 25 µg/mL, respectively. Among the different solvent–soluble fractions obtained from the ethanolic extract, the ethyl acetate (EtOAc) fraction was found to cause the most potent scavenging, or inhibitory activities, against 2,2-diphenyl-1-picrylhydrazyl (DPPH), peroxynitrite (ONOO⁻) and total ROS with the respective IC₅₀ values of 2.48 ± 0.01, 8.70 ± 0.06, and 0.81 ± 0.03 µg/mL. Likewise, the EtOAc fraction also exhibited potent inhibitory activities against AChE and BChE with IC₅₀ values of 2.78 ± 0.07 and 3.48 ± 0.32 µg/mL, respectively. Silica gel column chromatography of the EtOAc fraction yielded a phlorotannin, 974-B, based on the comparison with reported ¹H- and ¹³C-NMR spectroscopic data. 974-B showed strong scavenging/or inhibitory potential against DPPH, ONOO⁻, total ROS, AChE, and BChE with the respective IC₅₀ values of 0.86 ± 0.02, 1.80 ± 0.01, 6.45 ± 0.04, 1.95 ± 0.01, and 3.26 ± 0.08 µM, respectively. These results indicate that the potential of E. bicyclis and its phlorotannin for use in the development of therapeutic or preventive agents of Alzheimer’s disease mainly through ChE inhibition and additional antioxidant capacities.