Tannin extract characterization of young mangrove Rhizophora mucronata leaves as ingredients for diabetic functional food

Young leaves are often used as food and traditional medicines. Likewise the Rhyzophora plant that is widely used as a medicine and food are part of a young plant. The purpose of this study was to characterize the in vitro activity of antidiabetic using a-glucosidase enzymes and antioxidant activity with DPPH of young leaves tannin extract R. mucronata. Tannin extraction methods was carried out using acetone-water 70-30 and sonication at 40Hz amplitude for 30 minutes. Condensed tannins fractionation process is done by separating funnel using a solvent, hexane, chloroform, and ethyl acetate. The results showed that the inhibitory activity of the enzyme α-glucosidase by condensed tannins fraction is higher than the crude extract tannin young leaves R. mucronata and acarbose, as indicated by the IC₅₀ value were 25.08 ± 0.88 μg/mL (crude extract tannins) and 8.07 ± 0.58 μg/mL (fraction of condensed tannins), and 10.60 ± 0.20 μg mL (acarbose), respectively. Condensed tannins fractionation process reduces levels of total phenolic, total tannins and total flavonoids, but increases levels of condensed tannins. Although antidiabetic in vitro activity of the crude extract tannins and condensed tannins fraction is high, but the antioxidant activity were very weak as demonstrated IC₅₀ value were 981494.70 + 255.76 μg/mL (crude extract tannins) and 1725.18 ± 25.97 μg/mL (fraction of condensed tannins).