Inhibitory potential of Grifola frondosa bioactive fractions on α‐amylase and α‐glucosidase for management of hyperglycemia

Abstract

This study examined the inhibitory effects of Grifola frondosa (GF), a medicinal mushroom popularly consumed in traditional medicine and health food, on digestive enzymes related to type 2 diabetes; chemical profiles and inhibitory kinetics of its bioactive fractions were also analyzed. Results showed that all GF extracts showed weak anti-α-amylase activity; however, strong anti-α-glucosidase activity was noted on GF n-hexane extract (GF-H). Further fractionation confirmed that compared with acarbose (a commercial α-glucosidase inhibitor), the nonpolar fraction of GF possessed a stronger anti-α-glucosidase activity but a weaker anti-α-amylase activity. These activities were not derived from ergosterol and ergosterol peroxide, two major compounds of this fraction. The inhibitory kinetics of GF-H on α-glucosidase was competitive inhibition. GF-H was as good as acarbose in inhibiting the starch digestion in vitro. Oleic acid and linoleic acid could be the major active constituents that have contributed to the potency of GF in inhibiting α-glucosidase activity.

Effect of Black Tea and Black Tea Pomace Polyphenols on α-Glucosidase and α-Amylase Inhibition, Relevant to Type 2 Diabetes Prevention

“…It is well documented that phenolic phytochemicals are effective antioxidants ( 6 , 15 – 18 ) and our findings indicate that the antioxidant activities are in agreement with the phenolic contents (Figures 1 and 2 ).…”

“…Beside lifestyle change, which can prevent type 2 diabetes there are also food-based active ingredients, such as polyphenols, which have the ability to modulate blood glucose level ( 5 ). Recent research has shown that phenolic compounds have the potential to inhibit carbohydrate hydrolyzing enzymes in our digestive organs and thus have potential to play a role in management of type 2 diabetes ( 6 ).…”

“…The major source of glucose in our body comes from the hydrolysis of dietary carbohydrates, such as starch. The pancreatic alpha-amylase and intestinal alpha-glucosidases are the hydrolyzing enzymes responsible for glucose generation via diet ( 6 ). α-Amylase hydrolyzes alpha-1,4-glycocidic bonds and splits up starch components such as amylose and amylopectin into smaller oligosaccharides and disaccharides, like maltose.…”

“…This could be a good treatment for type 2 diabetes prevention ( 12 ). Specifically for tea, Kwon et al ( 6 ) reported that green tea had the lowest α-glucosidase inhibitory activity, followed by Oolong tea and black tea had the highest inhibitory activity. These findings suggest that the observed α-glucosidase inhibitory activity possibly depends on the catechin polymerization products that are produced during fermentation.…”

Ergosterol and its derivatives from Grifola frondosa inhibit antigen-induced degranulation of RBL-2H3 cells by suppressing the aggregation of high affinity IgE receptors

“…Grifola frondosa (G. frondosa), a basidiomycete fungus belonging to the Polyporaceae family, is a popular edible mushroom in Asia [1], and is consumed as a health food and/or traditional medicine. Previous studies have shown that G. frondosa has pharmacologic effects, such as anti-cancer [2][3][4], anti-inflammation [5] and anti-diabetes activity [6][7][8]. These immunomodulatory properties are noteworthy and several polysaccharides and/or proteins of G. frondosa were identified as its active components [1][2][3]7,9].…”