Philippine Journal of Science
151 (S1): 25-60, Marine Botany
ISSN 0031 – 7683
Date Received: 19 Apr 2021

α-Glucosidase Inhibitors from the Bark Extract
of Ethno-Antidiabetic Ceriops tagal (Perr.) C.B. Rob

Bernard S. Canusa¹, Ivan L. Lawag^2,7, Oliver B. Villaflores^1,3,4,
Vitthal D. Wagh⁵, Michal Korinek^5,8,9, Yi-Hong Tsai⁵, Fang-Rong Chang^5,10,11,12,
and Ma. Alicia M. Aguinaldo^1,3,6*

¹The Graduate School
University of Santo Tomas, España Blvd. 1015 Manila, Philippines
²Chemistry Department, College of Science, Adamson University
900 San Marcelino Street, Ermita, Manila 1000 Philippines
³Research Center for the Natural and Applied Sciences
Thomas Aquinas Research Complex
University of Santo Tomas, España Blvd. 1015 Manila, Philippines
⁴Department of Biochemistry, Faculty of Pharmacy
University of Santo Tomas, España Blvd. 1015 Manila, Philippines
⁵Graduate Institute of Natural Products, College of Pharmacy
Kaohsiung Medical University, Kaohsiung 807 Taiwan
⁶Department of Chemistry, College of Science
University of Santo Tomas, España Blvd. 1015 Manila, Philippines
⁷Division of Pharmacy, School of Allied Health
Faculty of Health and Medical Sciences
University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 Australia
⁸Graduate Institute of Natural Products, College of Medicine
Chang Gung University, Taoyuan 33302 Taiwan
⁹Research Center for Chinese Herbal Medicine
Research Center for Food and Cosmetic Safety, and
Graduate Institute of Health Industry Technology, College of Human Ecology
Chang Gung University of Science and Technology, Taoyuan 33302 Taiwan
¹⁰Drug Development and Value Creation Research Center
Kaohsiung Medical University, Kaohsiung 807 Taiwan
¹¹Department of Medical Research, Kaohsiung Medical University Hospital
Kaohsiung Medical University, Kaohsiung 807 Taiwan
¹²Department of Marine Biotechnology and Resources
National Sun Yat-sen University, Kaohsiung 804 Taiwan

*Corresponding author: amaguinaldo@ust.edu.ph

 

[Download]
Canusa B et al. 2022. α-Glucosidase Inhibitors from the Bark Extract of Ethno-Antidiabetic
Ceriops tagal (Perr.) C.B. Rob. Philipp J Sci 151(S1): 25–60. https://doi.org/10.56899/151.S1.03

 

ABSTRACT

The bark of Ceriops tagal has been used in the Philippines for folk treatment of diabetes mellitus (DM). Through an α-glucosidase inhibition assay guided isolation, constituents from the detannified methanolic bark extract were isolated and identified to be methyl 2,4-dihydroxy-3,6- dimethyl benzoate (1), isopimar-7-ene-15S,16-diol (2), betulinic acid (3), lupeol (4), and methyl 2,4-dihydroxy-6-methyl benzoate (5). Compounds 3 (IC50 = 5.31 µM) and 4 (IC50 = 55.84 µM) showed a more potent activity against α-glucosidase than the positive control, 1-deoxynojirimycin (IC50 = 79.16 µM). This is the first report on the presence of the weakly active compounds (1, 2, and 5) (IC50 > 75 µM) in the genus Ceriops and the first report on the biological activity of Compound 2. Enzyme kinetic studies suggested that betulinic acid is an uncompetitive type of inhibitor, with lupeol as a non-competitive type. This study provides evidence on the possible mechanism of the antidiabetic property of C. tagal associated with its traditional use. It supports the possible utilization of the bark for development to prevent or treat diabetes.