Background and Objective: Diabetes increasingly represents a
major global concern, especially in developing countries and particularly in
Sub-Saharan Africa. According to WHO, the world-wide prevalence of diabetes has
almost doubled since 1980, from 4.7% to 8.5% in 2014 in the adult population.
The primary objective of this study is to determine the inhibitory activity of
methanolic leaf extract of Piper umbellatum and Persea americana (P. americana)
(traditionally used in Cameroon against diabetes) on 𝛼-glucosidase,
𝛽-glucosidase,
maltase-glucoamylase, aldose reductase and aldehyde reductase activities,
enzymes involved in starch digestion or diabetic complications.
Methods: The methanol extracts from Piper umbellatum and P.
americana were prepared by maceration. To assess the relative efficacy of these
extracts, the determination of concentrations that were needed to inhibit 50%
of enzyme activity was done, whereas, gas chromatography-mass spectrum was used
to identify components from extracts that may be responsible for the
activities. Differences in calculated percent inhibition and IC50 values were
analyzed using unpaired t-tests as well as one-way ANOVA followed by
Tukey-Kramer post-hoc analysis in order to compare data sets.
Results: The tested extracts strongly inhibited 𝛼-glucosidase,
maltase-glucoamylase, aldose reductase and aldehyde reductase activities with
IC50 ranging from (1.07 ± 0.03) to (31.77 ± 1.17) µg/mL. Among the tested
extracts, P. americana was the most active against sensitive enzymes (IC50 of
1.07 ± 0.03 to 15.63 ± 1.23). However, none of the extracts showed an
interesting inhibitory effect against 𝛽-glucosidase as their
percentage inhibitions were less than 16%. From gas chromatography-mass
spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and
P. americana extracts respectively, using NIST library 2014.
Conclusions: The results of this study provide the
scientific credentials for the prospective usage of these plants to treat
diabetes. Further work is still needed for the identification of specific
anti-hyperglycemic constituents in these extracts and the evaluation of their
pharmacological potentials.
Author(s) Details
Guy Sedar Singor
Njateng
Laboratory of Microbiology and Antimicrobial Substances,
Faculty of Science, University of Dschang, P.O. Box 67 Dschang, Cameroon and
Centre for Advanced Drug Research, COMSATS Institute of Information Technology,
Abbottabad-22060, Pakistan.
Jamshed Iqbal
Centre for Advanced Drug Research, COMSATS Institute of
Information Technology, Abbottabad-22060,
Pakistan.
Please see the book here:- https://doi.org/10.9734/bpi/mria/v9/7785E
