Improvement of Glycemic Control by a Functional Food Mixture Containing Maltodextrin, White Kidney Bean Extract, Mulberry Leaf Extract, and Niacin-Bound Chromium Complex in Obese Diabetic db/db Mice

Abstract

Steady-fiber granule (SFG) is a mixture containing maltodextrin, white kidney bean extract, mulberry leaf extract, and niacin-bound chromium complex. These active ingredients have been shown to be associated with improving either hyperglycemia or hyperlipidemia. This study was undertaken to evaluate the potential of SFG in the regulation of blood glucose homeostasis under obese diabetic conditions. Accordingly, db/db mice (8 weeks old) were administered with SFG at doses of 1.025, 2.05, or 5.125 g/kg BW daily via oral gavage for 4 weeks. No body weight loss was observed after SFG supplementation at all three doses during the experimental period. Supplementation of SFG at 2.05 g/kg BW decreased fasting blood glucose, blood fructosamine, and HbA1c levels in db/db mice. Insulin sensitivity was also improved, as indicated by HOMA-IR assessment and oral glucose tolerance test, although the fasting insulin levels were no different in db/db mice with or without SFG supplementation. Meanwhile, the plasma levels of triglyceride were reduced by SFG at all three doses. These findings suggest that SFG improves glycemic control and insulin sensitivity in db/db mice and can be available as an option for functional foods to aid in management of type 2 diabetes mellitus in daily life.

Keywords: functional foods; hyperglycemia; insulin resistance; steady-fiber granule; type 2 diabetes mellitus.

Figure 1

A flowchart of the study showing experimental timeline.

Figure 2

Effects of SFG supplementation on fasting blood glucose, fasting insulin, and insulin sensitivity in db/db mice. C57BL/6J mice received the vehicle (distilled water) as a control, while db/db mice received the vehicle and SFG (1.025, 2.05, and 5.125 g/kg BW) for 4 weeks; groups are denoted as db/db, SFG 1.025, SFG 2.05, and SFG 5.125, respectively. Fasting blood glucose (A), fasting plasma insulin levels (B), and HOMA-IR (C) were then measured after 12 h fasting. Results are expressed as the mean ± SD, n = 8. A significant difference is indicated by superscript letters according to one-way with ANOVA post hoc Duncan’s multiple range test. Different superscript letters indicate statistical significance (p < 0.05).

Figure 3

Effects of SFG supplementation on blood fructosamine and HbA1c levels. C57BL/6J mice received the vehicle (distilled water) as a control, while db/db mice received the vehicle and SFG (1.025, 2.05, and 5.125 g/kg BW) for 4 weeks; groups are denoted as db/db, SFG 1.025, SFG 2.05, and SFG 5.125, respectively. After fasting for 12 h, a blood sample was collected for the detection of HbA1c (A) and fructosamine (B) levels. Results are expressed as the mean ± SD, n = 8. A significant difference is indicated by superscript letters according to one-way ANOVA with Tukey post hoc test. Different superscript letters indicate statistical significance (p < 0.05).

Figure 4

Effects of SFG supplementation on blood glucose levels and area under curve (AUC) during OGTT. C57BL/6J mice received the vehicle (distilled water) as a control, while db/db mice received the vehicle and SFG (1.025, 2.05, and 5.125 g/kg BW) for 4 weeks; groups are denoted as db/db, SFG 1.025, SFG 2.05, and SFG 5.125, respectively. After fasting for 12 h, mice were subjected to the oral glucose tolerance test (OGTT). Blood was sampled and examined at 0 (baseline), 30, 60, 90, and 120 min for glucose levels. Results are expressed as the mean ± SD, n = 8. * p < 0.05 as compared to the control mice; ^# p < 0.05 as compared to the db/db mice (A). AUC was calculated, and the statistical significance was indicated by superscript letters according to one-way ANOVA with post hoc Duncan’s multiple range test (B). Different superscript letters indicate statistical significance (p < 0.05).