Inhibition of α-Glucosidase, Acetylcholinesterase, and Nitric
Oxide Production by Phytochemicals Isolated from Millettia
speciosa—In Vitro and Molecular Docking Studies
Authors: Nguyen Ngoc Tuan , Huong Nguyen Thi, Chau Le Thi My, Tang Xuan Hai, Hieu Tran Trung, Anh Nguyen Thi Kim, Thanh Nguyen Tan , Tan Le Van , Cuong Quoc Nguyen , Quang De Tran, Ping-Chung Kuo , Quang Le Dang, Tran Dinh Thang
plants
: 11 : 388-405
Publishing year: 1/2022
The phytochemical constituents from the roots of Millettia speciosa were investigated by chromatographic isolation, and their chemical structures were characterized using the MS and NMR spectroscopic methods. A total of 10 compounds, including six triterpenoids, two flavonoids, and two phenolic compounds, were identified from the roots of M. speciosa. Out of the isolated compounds, eight showed inhibitory effects on NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, with IC50 values ranging from 43.9 to 449.5 µg/mL. Ursane-type triterpenes significantly
suppressed NO production compared to the remaining compounds. In addition, these compounds
also exhibited remarkable inhibitory effects on α-glucosidase. Among the tested compounds, 4, 5,
and 10 exhibited excellent α-glucosidase inhibition, with IC50 values ranging from 1.1 to 2.2 µg/mL.
Almost all of the test compounds showed little or no acetylcholinesterase inhibition, except for 5,
which showed moderate anti-acetylcholinesterase activity in vitro. The molecular docking study of
α-glucosidase inhibition by 3–5 and 10 was conducted to observe the interactions of these molecules
with the enzyme. Compounds 4, 5, and 10 exhibited a better binding affinity toward the targeted
receptor and the H-bond interactions located at the entrance of the enzyme active site pocket in
comparison to those of 3 and the positive control acarbose. Our findings evidence the pharmacological
potential of this species and suggest that the phytochemicals derived from the roots of M. speciosa ay be promising lead molecules for further studies on the development of anti-inflammatory and anti-diabetes drugs.
Millettia speciosa; molecular docking; NO production; anti-glucosidase; anti-acetylcholinesterase