In Vitro and In Vivo Effects of Norathyriol and Mangiferin on α-Glucosidase

Abstract

Norathyriol is a metabolite of mangiferin. Mangiferin has been reported to inhibit α-glucosidase. To the best of our knowledge, no study has been conducted to determine or compare those two compounds on inhibiting α-glucosidase in vitro and in vivo by far. In this study, we determined the inhibitory activity of norathyriol and mangiferin on α-glucosidase in vitro and evaluated their antidiabetic effect in diabetic mice. The results showed that norathyriol inhibited α-glucosidase in a noncompetitive manner with an IC50 value of 3.12 μM, which is more potent than mangiferin (IC50 = 358.54 μM) and positive drug acarbose (IC50 = 479.2 μM) in the zymological experiment. Both of norathyriol and mangiferin caused significant (p < 0.05) reduction in fasting blood glucose and the blood glucose levels at two hours after carbohydrate loading and it was interesting that mangiferin and norathyriol can make the decline of the blood glucose earlier than other groups ever including normal group in the starch tolerance test. However, norathyriol and mangiferin did not significantly influence carbohydrate absorption in the glucose tolerance test. Therefore, the antidiabetic effects of norathyriol and mangiferin might be associated with α-glucosidase, and norathyriol was more potent than mangiferin.

Comparison of Antioxidant and α-Glucosidase Inhibitory Activities in Different Cultivars of Five Mango (Mangifera Indica L.) Leaf Extracts

“…'Apple' exhibits the considerable potential to possibly delay the absorption of glucose via the inhibition of α-glucosidase enzyme. All mango cultivars exhibited inhibition type of non-completive inhibition which is accordance with that of the major active compound, mangiferin (Shi et al, 2017).…”

“…Gallic acid can increase GLUT-4 translocation concomitant with enhance glucose uptake activity (Prasad et al, 2010). Mangiferin and its metabolite, norathyriol, have been determined for anti-diabetic effects by various mechanisms such as lowering blood glucose level, improvement the glucose utilization and insulin sensitivity by upregulation of the phosphorylation of AMPK (Aderibigbe et al, 1999, Imran et al, 2017, Shi et al, 2017.…”

Bridelia speciosa Müll.Arg. Stem bark Extracts as a Potential Biomedicine: From Tropical Western Africa to the Pharmacy Shelf

“…On the other hand, it was also reported that corilagin (IC 50 = 1.231 mM) was active against tyrosinase [48]. Mangiferin was reported to exert a non-competitive inhibition of α-glucosidase [49]. The methanol and water extracts were selected for further biological assays based on the results of colorimetric analyses indicating a more promising phytochemical profile in terms of total phenols and antiradical activity.…”

Synthesis, In Vitro Evaluation and Molecular Docking of the 5-Acetyl-2-aryl-6-hydroxybenzo[b]furans against Multiple Targets Linked to Type 2 Diabetes

“…The following compounds were prepared in this fashion. The α-glucosidase inhibitory activity of compounds 2a-h was evaluated in triplicates in a 96 well microplate following a protocol by Shi et al [24]. In a 96-well plate, α-glucosidase (20 µL of enzyme solution of 0.48 U/mL in 100 mM phosphate buffer of pH 6.8) was incubated with different concentrations (0-100 µM) of the test compounds (2a-h and acarbose as positive control) in DMSO at 37 • C, for 10 min.…”