Antidiabetic (α-amylase and α-glucosidase) and anti-obesity (lipase) inhibitory activities of edible cassava (Manihot esculenta Crantz) as measured by in vitro gastrointestinal digestion: effects of phenolics and harvested time.

Edible cassava leaves (Manihot esculenta) were consumed as vegetables for
their bioactive compounds, however the effect of harvesting time on these
bioactive compounds and their antidiabetic and anti-obesity inhibitory activities
were scarcely reported in the literature. Phenolics from edible leaves
harvested at different times were assessed using HPLC-DAD, and their antidiabetic
and anti-obesity inhibitory activities were investigated before and
after in vitro gastrointestinal digestion. The results showed a significant
(P < .05) effect of harvesting time on phenolic contents. Bound phenolics
showed higher lipase inhibitory activity than their free fractions. However,
phenolic contents decreased after in vitro digestion, while they showed high
antidiabetic and anti-obesity inhibitory activities. The present study demonstrated
that edible leaves harvested at different times are rich in flavonoids,
stilbenes, tannins and saponins. These bioactive compounds are highly
potent against α-amylase, α-glucosidase and lipase before and after in vitro
gastrointestinal digestion. Therefore, we recommend edible cassava leaves
for important biological active compounds for the prevention of obesity and
type 2 diabetes.