In vitro inhibition of starch digestive enzymes by ultrasound-assisted extracted polyphenols from Ascophyllum nodosum seaweeds
Seaweeds are gaining importance due to their antidiabetic characteristics. This study investigated the inhibitory effects of aqueous Ascophyllum nodosum extracts, obtained by ultrasound-assisted extraction with different sonication powers (70-90 W/cm2 ) and subjected to resin purification, against α-amylase and α-glucosidase enzymes. Different inhibition methodologies were carried out, preincubating the extract either with the enzyme or the substrate. Chemical characterization, in terms of proximate analysis, antioxidant capacity (2,2-diphenyl-1-picryl-hydrazyl-hydrate [DPPH] and FRAP), and polyphenols characteristics (reversed-phase high-performance liquid chromatography [RP-HPLC] and 1 H-NMR) were carried out to explain inhibitory activities of extracts. Sonication power did not influence the proximal composition nor antiradical activity of extracts, but increasing sonication power increased inhibition capacity (>15%) against both starch digestive enzymes. The extract purification largely improved the inhibition efficiency decreasing the IC50 of α-amylase and α-glucosidase by 3.0 and 6.1 times, respectively. Seaweed extracts showed greater inhibition effect when they were preincubated with the enzyme instead of the substrate. RP-HPLC together with 1 H-NMR spectra allowed relating the presence of uronic acids-polyphenols complexes and quinones in the extracts with the different inhibitory capacities of samples. PRACTICAL APPLICATION: The study confirms that ultrasound-assisted extracts from Ascophyllum nodosum can be used to inhibit digestive enzymes. This opens the alternative to be used in foods for modulating glycemic index.
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | artículo biblioteca |
| Language: | English |
| Published: |
John Wiley & Sons
2022-05-19
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| Subjects: | 1H-NMR, HPLC, Gelled starch, Wheat, α-amylase, α-glucosidase, |
| Online Access: | http://hdl.handle.net/10261/271612 http://dx.doi.org/10.13039/501100010801 http://dx.doi.org/10.13039/501100003359 http://dx.doi.org/10.13039/501100004837 |
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