Anti-hyperglycemic Effect of Diacylated Anthocyanin Derived fromIpomoea batatasCultivar Ayamurasaki Can Be Achieved through the α-Glucosidase Inhibitory Action

Abstract

To clarify a postprandial glucose suppression effect of diacylated anthocyanin with alpha-glucosidase (AGH) inhibitory activity, a single oral administration study of it in male 8-week-old Sprague-Dawley rats was performed. The diacylated anthocyanin used in this study was peonidin 3-O-[2-O-(6-O-E-feruloyl-beta-D-glucopyranosyl)-6-O-E-caffeoyl-beta-D-glucopyranoside]-5-O-beta-D-glucopyranoside isolated from storage roots of the purple sweet potato (Ipomoea batatas cv. Ayamurasaki), which showed a potent maltase inhibitory activity with an IC(50) value of 200 microM preferable to sucrase inhibition. When the diacylated anthocyanin (100 mg/kg) was administered following maltose (2 g/kg), a maximal blood glucose level (BGL) at 30 min was significantly decreased by 16.5% (P < 0.01) compared to vehicle. A minimum 10 mg/kg dose of the anthocyanin was necessary for the suppression of glycemic rise, and the ED(20) (69 mg/kg) was estimated to be approximately 30-fold lower than that of the therapeutic drug acarbose (ED(20) = 2.2 mg/kg). A reduction of serum insulin secretion was also observed corresponding to the decrease in BGL. No significant change in BGL was observed when sucrose or glucose was ingested, suggesting that the anti-hyperglycemic effect of the anthocyanin was achieved by maltase inhibition, not by sucrase or glucose transport inhibition at the intestinal membrane.

Anthocyanin-rich Phytochemicals from Aronia Fruits Inhibit Visceral Fat Accumulation and Hyperglycemia in High-fat Diet-induced Dietary Obese Rats

“…Anthocyanin reportedly inhibits α-glucosidase 29,30 and the present data and previous studies suggest that aronia phytochemicals inhibit sucrase. Furthermore, Matsui et al showed that when sweet potato peonidin glucoside was administered following glucose and maltose ingestion, blood glucose levels decreased compared with vehicle, but not sucrose 31 .…”

Differential Effects of Cyanidin and Cyanidin-3-glucoside on Human Cell Lines

“…Anthocyanins and their aglycons, anthocyanidins, have various biological effects, such as antioxidative activity (Cao et al, 1997;Kahkonen and Heinonen, 2003;Rahman et al, 2006;Tsuda et al, 1999a), anti-hyperglycemic activity (Matsui et al, 2002), anti-inflammatory activity (Karlsen et al, 2007;Wang et al, 2008b), cell protective activity (Elisia and Kitts, 2008;Tarozzi et al, 2007) and antitumor activity (Hou, 2003;Lala et al, 2006;Kang et al, 2003). One major anthocyanidin is cyanidin, and the effects of cyanidin and cyanin, its glycoside, have been investigated, but the biological effects of these compounds are not fully understood.…”

On farm and fresh produce management

“…A number of anthocyanins have been reported to show anticarcinogenic activity and in a recent study a black carrot anthocyanin-rich extract was shown to inhibit proliferation of two human cancer cell lines [122]. The acylated anthocyanins are thought to show enhanced bioactivity and sweet potato (Ipomoea batatas) acylated anthocyanins show strong anti-mutagenic, radical scavenging, anti-hypertensive and anti-hyperglycemic effects [101,122].…”