The Effect of Bioactive Polyphenols from <i>Anacardium occidentale</i> Linn. Leaves on α-Amylase and Dipeptidyl Peptidase IV Activities

Abstract

Anacardium occidentale Linn. (A. occidentale L.) leaves possess bioactive polyphenols which are associated with antidiabetic potency for the management of type 2 diabetes mellitus (T2DM). In this study, free, soluble ester, and insoluble-bound phenolic fractions from young and mature leaves of A. occidentale L. were extracted. Subsequently, all fractions were investigated for their inhibitory effect on α-amylase and dipeptidyl peptidase IV (DPPIV) activities. Both free (72.45 ± 3.6%) and soluble ester (83.40 ± 4.7%) phenolic fractions in the mature leaves extracts had significantly demonstrated greater α-amylase inhibitors than the young leaves. Likewise, soluble ester (4.09 ± 0.34 µg/mL) and insoluble-bound (4.87 ± 0.32 µg/mL) phenolic fractions in the mature leaves extracts were significantly more effective in inhibiting DPPIV than the young leaves. As for fractions comparison, insoluble-bound derived from the young leaves extract was a more potent α-amylase inhibitor than free and soluble ester phenolic fractions (p &lt; 0.0001). Besides, soluble ester and insoluble-bound phenolic fractions showed a stronger inhibitor of DPPIV than the free phenolic (p &lt; 0.001), irrespective of the maturity of the leaves. In conclusion, this study showed that A. occidentale L. extracts possessed antidiabetic properties, which may potentially be used as an alternative treatment for T2DM management.

Fractionation, identification of chemical constituents, and biological properties of cashew (Anacardium occidentale L.) leaf extracts

“…The α‐amylase inhibition assay was adapted from Thaidi et al ( 2020 ), with minor modifications. Briefly, the samples (crude extract and fractions) were serially diluted in DMSO to obtain different concentrations (25–400 μg/mL).…”

“…All experiments were established in triplicate and performed until MICs were constant.The minimum microbicidal concentration (MMC) value was estimated by plating 10 μL of the test material from the wells where no indicator color change was observed onto the MHB medium. The MMC value was then determined as the lowest concentration without growth (no colony) at the end of the incubation period.2.7 | Determination of antidiabetic activity2.7.1 | In vitro α-amylase inhibitionThe α-amylase inhibition assay was adapted fromThaidi et al (2020), with minor modifications. Briefly, the samples (crude extract and fractions) were serially diluted in DMSO to obtain different concentrations (25-400 μg/mL).…”

Extraction of flavonoids from durian (Durio zibethinus) fruit rinds and evaluation of their antioxidant, antidiabetic and anticancer properties

“…The α-amylase inhibition assay was conducted according to the method of Thaidi et al (2020) with minor changes. The extracts were prepared in DMSO at different concentrations (100-1000 μg mL À1 ) while αamylase (2 U mL À1 ) was prepared in a phosphate buffer solution (pH 6.9).…”