Page 64 - Book of Abstracts

th
8 Biannual Conference on Chemistry - CHEM 08

Flavonoid-Rich Extract of Dacryodes Edulis Leaves Improves
the Antidiabetic Activity of Acarbose In vitro

Ononamadu Ch. James
Department of Biochemistry & Forensic Science, Nigeria Police Academy,
Wudil, Kano State, Nigeria.
ABSTRACT
Diabetes mellitus is a complex and multifaceted metabolic disorder. It is
hypothesized that treatment options with multimodal mechanism of action may
prove more effective in management of the disease relative to conventional drugs
with mono-modal mechanism of action. Acarbose is a commercially available
inhibitor of pancreatic α-amylase used in managing postprandial
hyperglycemia. There is a growing evidence that suggests flavonoids and
flavonoid rich extract have great potential of ameliorating complex metabolic
disorders. Thus, this study investigated the combined effect of a flavonoid-rich
extract of Dacryodes edulis leaves and acarbose with respect to inhibition of
carbolytic enzyme activity, uptake of glucose by yeast cell model, radical
scavenging and reducing power activities in vitro. The extract was obtained via
maceration in methanol and subsequent solvent/solvent partition and
fractionation. The phytochemicals were determined by LC-MS and spectroscopic
methods. Aqueous solutions of the extract (500µg/ml) and acarbose (500µg/ml)
were combined in different ratios (100;0, 25:75, 50:50, 75:25 and 0:100) and the
antioxidant activities, effect on carbolytic enzyme activity and glucose uptake
were determined by standard methods. The phytochemical analysis revealed
high content of total phenolics (201mg gallic acid equivalence/g) and flavonoids
(184 mg rutin equivalence/g). The following flavonoids were identified by LC-
MS: Vitexin, Quercetin-3-O-rutinoside, Isovitexin-7-O-glucoside, Fisetin-4-
glucoside, Kaemferol-3-O-β-sophoroside, Acacetin-7-rutinoside, Isovitexin-7-O-
rhamnoside and Tricin. The addition of the extract significantly (p<0.05)
increased the inhibition of α-glucosidase but slightly reduced the inhibition of α-
amylase by Acarbose. The extract in combination with acarbose also significantly
improved the DPPH scavenging activity, reducing power, and glucose uptake in
yeast cell model. The optimal extract-acarbose combination ratio observed was
75:25. In conclusion, the study demonstrated that flavonoid-rich extract have
great potential to improve the action of acarbose with respect to glycemic control
and amelioration of oxidative stress. However, further, work should be devoted
to explore this potential in vivo in diabetic animal models.
Keywords: Flavonoids, Acarbose, Diabetes mellitus, Combination-Therapy.

BOOK OF ABSTRACTS CHEM 08 (2020) Page 63