Oligomeric Proanthocyanidin Complex from Avocado Seed as A Promising α-glucosidase Inhibitor: Characteristics and Mechanisms

Abstract

Although considered an abundant source of agricultural by-products, avocado (Persea americana Mill.) seed, with several biological activities and bioactive components, might become a promising resource for phytopharmaceutical development. In this study, through bioassay-guided isolation of the main α-glucosidase inhibitors in avocado seed, we discovered the major α-glucosidase inhibitor to be avocado seed oligomeric proanthocyanidin complex (ASOPC). Thiolysis and UPLC-DAD-HRESIMS showed the presence of A- and B-type procyanidins, and B-type propelargonidin with (epi)afzelechin as extension unit. Mean degree of polymerization (mDP) of ASOPC was calculated as 7.3 ± 1. Furthermore, ASOPC appeared to be a strong, reversible, competitive inhibitor of α-glucosidase, with IC₅₀ value of 0.1 µg/mL, which was significantly lower than Acarbose (IC₅₀ = 75.6 µg/mL), indicated that ASOPC is a potential natural α-glucosidase inhibitor. These findings would contribute to the direction of utilizing avocado seed bioactive components with the possibility to be used as natural anti-diabetic agents.

Key words

Avocado seed - Persea americana - Lauraceae - diabetes mellitus - α-glucosidase inhibitory activity - proanthocyanidins

Publication History

Received: 15 February 2022

Accepted after revision: 17 June 2022

Accepted Manuscript online:
17 June 2022

Article published online:
28 September 2022

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