Asian medicine’s black ridge oak has bioactive constituents that demonstrate a-glucosidase inhibitor activity

Researchers from Ehime University in Japan evaluated the antidiabetic and antioxidant potentials of constituents isolated from the leaves of black ridge oak (Quercus phillyraeoides). They published their results in the journal Food Science and Human Wellness.

• Black ridge oak is an evergreen tree found in East Asia.
• The leaves of the black ridge oak are used in Korean folk medicine for ailments, such as diarrhea.
• They assessed the extract’s antidiabetic properties in terms of its ability to inhibit an intestinal carbohydrate-digesting enzyme called alpha-glucosidase.
• Alpha-glucosidase is an enzyme that plays a key role in the absorption of glucose in the gastrointestinal tract.
• The researchers identified six compounds from the black ridge oak leaf extract: beta-sitosterol d-constituents (1) and condensed tannin fractions (2, 3, 4, 5, and 6).
• They tested the inhibitory activities of these compounds against alpha-glucosidase from baker’s yeast (Saccharomyces cerevisiae).
• They also examined the inhibitory activity of quercetin against baker’s yeast for comparison, as it exhibited potent inhibitory effects on alpha-glucosidase in a previous study.
• The researchers also evaluated the antioxidant activities of the compounds using different antioxidant assays.
• Results revealed that compound 1 showed moderate activity as an ?-glucosidase inhibitor, while fractions 2 to 6 exhibited higher inhibitory activities.
• The isolated constituents also exhibited potent antioxidant activities.

These findings suggested black ridge oak leaf could be used as a rich source of natural antioxidant and antidiabetic medicine.

Read the full text of the study at this link.

Read more studies on natural antidiabetes medicines like black ridge oak at PreventDiabetes.news.

Journal Reference:

Indrianingsih AW, Tachibana S. BIOACTIVE CONSTITUENTS FROM THE LEAVES OF QUERCUS PHILLYRAEOIDES A. GRAY FOR ?-GLUCOSIDASE INHIBITOR ACTIVITY WITH CONCURRENT ANTIOXIDANT ACTIVITY. Food Science and Human Wellness. June 2016; 5(2): 85-94. DOI: 10.1016/j.fshw.2016.02.004