Hydrolysable Tannins Exhibit Acetylcholinesterase Inhibitory and Anti-Glycation Activities In Vitro and Learning and Memory Function Improvements in Scopolamine-Induced Amnesiac Mice

Lih-Geeng Chen; Shyr-Yi Lin; Yi-Shan Lee; Ching-Chiung Wang; Wen-Chi Hou

doi:10.3390/biomedicines9081066

Hydrolysable Tannins Exhibit Acetylcholinesterase Inhibitory and Anti-Glycation Activities In Vitro and Learning and Memory Function Improvements in Scopolamine-Induced Amnesiac Mice

Biomedicines. 2021 Aug 23;9(8):1066. doi: 10.3390/biomedicines9081066.

Authors

Lih-Geeng Chen^{1

2}, Shyr-Yi Lin^{3

4}, Yi-Shan Lee⁵, Ching-Chiung Wang^{2

5

6}, Wen-Chi Hou⁵

Affiliations

¹ Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi 600, Taiwan.
² Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei 110, Taiwan.
³ Department of General Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
⁴ Department of Internal Medicine, Division of Gastroenterology, Wan Fang Hospital, Taipei Medical University, Taipei 116, Taiwan.
⁵ Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei 110, Taiwan.
⁶ School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 110, Taiwan.

Abstract

Agricultural waste from the hulls of water caltrop (Trapa taiwanesis Nakai, TT-hull) was extracted by either steeping them in cold 95% ethanol (C95E), refluxing 95E, refluxing 50E, or refluxing hot water (HW) to obtain C95EE, 95EE, 50EE, and HWE, respectively. These four extracts showed acetylcholinesterase (AChE) inhibitory activities and free radical scavenging activities, as well as anti-non-enzymatic protein glycation in vitro. Eight compounds were isolated from TT-hull-50EE and were used to plot the chromatographic fingerprints of the TT-hull extracts, among which tellimagrandin-I, tellimagrandin-II, and 1,2,3,6-tetra-galloylglucose showed the strongest AChE inhibitory activities, and they also exhibited anti-amyloid β peptide aggregations. The scopolamine-induced amnesiac ICR mice that were fed with TT-hull-50EE or TT-hull-HWE (100 and 200 mg/kg) or tellimagrandin-II (100 and 200 mg/kg) showed improved learning behavior when evaluated using passive avoidance or water maze evaluation, and they showed significant differences (p < 0.05) compared to those in the control group. The enriched hydrolysable tannins of the recycled TT-hull may be developed as functional foods for the treatment of degenerative disorders.

Keywords: acetylcholinesterase; passive avoidance; scopolamine; water caltrop hulls; water maze.