Plants provide excellent sources of medicinal compounds. Over 5000 flavonoids have
been isolated and identified from plant sources. Flavonoids are polyphenolic compounds
mainly recognized as pigments which produce the colors found in flowers, fruit and leaves.
Dietary polyphenols are commonly found in plants and are abundant in fruit, vegetables,
chocolate, and nuts. These polyphenols also found in beverages including tea, coffee,
wine, and soy milk. Flavonoids are known to lower glucose levels, decrease cholesterol
and triglycerides, and increase liver enzyme levels most likely by stimulating pancreatic
insulin release. By activating cell-signaling pathways involved in controlling blood glucose
levels, flavonoids aid in carbohydrate digestion, and adipose deposition. Flavonoids
containing isoflavones, flavanols, flavanones, flavonols, flavones, and anthocyanins
have been studied from clinic study until pre clinic study. However, not all of the studies
conducted had adequate results. Isoflavone is one of the potential flavonoids that still can
be explored for future research. Research on isoflavone supplementation in animals and
humans in reducing blood glucose levels is still limited. Short-term supplementation did
not improve blood glucose levels in postmenopausal women, while other studies suggest
that the long-term isoflavone supplementation can reduce postmenopausal blood glucose
levels. These findings found that isoflavone is a component of flavonoids that have potency
in reducing blood glucose levels.