Page 138 - Acrobat J Trad-21-3-2566

J Thai Trad Alt Med Vol. 21 No. 3 Sep-Dec 2023 621

functional food. However, additional in-depth twice. The extracts were combined and dried
in vitro, in vivo and clinical studies on efficacy by using a freeze dryer. All extracts were stored

of Kratom should be conducted to confirm its at -20˚C until used.
potential.
2. Chemicals and reagents

Methodology Donepezil and captopril were purchased

from USP (Rockville, MD, USA). and acarbose
1. Plant materials and preparations were purchased from Sigma (Darmstadt, Ger-

Kratom leaves were collected from Trang many). They were utilized as positive control
province, Thailand, in December 2021 and in their corresponded enzymatic assays. In
authenticated by the Medical Plant Research anti-Alzheimer’s assay, acetylcholinesterase

Institute, Department of Medical Science, enzyme (AChE), butyrylcholinesterase enzyme
Thailand. The plant specimen (voucher num- (BuChE), acetylthiocholine iodide (ACTI),

ber DMSC 5290) was deposited at the her- butyrylthiocholine iodide (BuTI), 5,5′-dithiobis-
barium of Medicinal Plant Research Institute, 2-nitrobenzoic acid (DNTB), bovine serum
Department of Medical Sciences, Ministry of albumin (BSA) and tris-(hydroxymethyl) ami-

Public Health, Nonthaburi, Thailand. nomethane (Tris-base) were purchased from
Kratom leaves were washed and then Sigma (Darmstadt, Germany). For antihyper-

dried in a hot air oven at a temperature of tension, angiotensin-converting enzyme (ACE)
45˚C. The dried Kratom leaves were ground from rabbit lung, Hippuryl-His-Leu (HHL) and
into coarse powder and were extracted Tris–HCl were purchased from Sigma (Darm-

separately by maceration, and decoction stadt, Germany). Purified water was prepared
methods. For maceration, the coarse powder by the Milli Q system from Millipore (Bedford,
®
of Kratom leaves were separately macerated MA, USA). Acetonitrile (HPLC grade) was

with 95%ethanol, 70%ethanol, and 50%ethanol. purchased from Labscan (Bangkok, Thailand).
Each extract was filtered and dried under re- In anti-diabetes assay, alpha-glucosidase
duced pressure at a temperature below 45˚C. and alpha-amylase enzymes, p-nitrophenyl

The residue was re-extracted by a similar alpha-D-glucopyranoside (p-NPG), starch,
process twice. For decoction, Kratom leaves potassium sodium tartrate, tetrahydrate,

were boiled in distilled water for 15 minutes. 3,5-dinitrosalicylic acid were purchased from
The extract was filtered with filter paper. The sigma (Darmstadt, Germany).
residue was re-extracted by a similar process