Effects of unaltered and bioconverted mulberry leaf extracts on cellular glucose uptake and antidiabetic action in animals

Abstract

Background Mulberry is a Korean medicinal herb that shows effective prevention and treatment of obesity and diabetes. Bioconversion is the process of producing active ingredients from natural products using microorganisms or enzymes. Methods In this study, we prepared bioconverted mulberry leaf extract (BMLE) with Viscozyme L, which we tested in insulin-sensitive cells (i.e., skeletal muscle cells and adipocytes) and insulin-secreting pancreatic β-cells, as well as obese diabetic mice induced by co-administration of streptozotocin (100 mg/kg, IP) and nicotinamide (240 mg/kg, IP) and feeding high-fat diet, as compared to unaltered mulberry leaf extract (MLE). Results BMLE increased the glucose uptake in C2C12 myotubes and 3 T3-L1 adipocytes and increased glucose-stimulated insulin secretion in HIT-T15 pancreatic β-cells. The fasting blood glucose levels in diabetic mice treated with BMLE or MLE (300 and 600 mg/kg, PO, 7 weeks) were significantly lower than those of the vehicle-treated group. At the same concentration, BMLE-treated mice showed better glucose tolerance than MLE-treated mice. Moreover, the blood concentration of glycated hemoglobin (HbA 1C ) in mice treated with BMLE was lower than that in the MLE group at the same concentration. Plasma insulin levels in mice treated with BMLE or MLE tended to increase compared to the vehicle-treated group. Treatment with BMLE yielded significant improvements in insulin resistance and insulin sensitivity. Conclusion These results indicate that in the management of diabetic condition, BMLE is superior to unaltered MLE due to at least, in part, high concentrations of maker compounds (trans-caffeic acid and syringaldehyde) in BMLE. Electronic supplementary material The online version of this article (10.1186/s12906-019-2460-5) contains supplementary material, which is available to authorized users.

Extended Intake of Mulberry Leaf Extract Delayed Metformin Elimination via Inhibiting the Organic Cation Transporter 2

“…In particular, chlorogenic acid suppresses hepatic gluconeogenesis via both the inhibition of glucose-6-phosphatase (G6Pase) activity and the activation of AMP-dependent kinase (AMPK) [11,12]. In addition, it is reported that the trans-caffeic acid has ability to increase glucose uptake in muscle and GLUT-4 expression in skeletal muscles [30]. MLE used in this study includes the trans-caffeic acid, syringaldehyde and chlorogenic acid, thus results in this study were also supported by the previous investigations reported the anti-hyperglycemic effect of trans-caffeic acid, rutin, and chlorogenic acid in DM rats [11,12].…”

“…Also, there is another hypothesis. Met is metabolized by hepatic CYP2C11, 2D1, and 3A1/2, and eliminated via the kidneys in rats [30]. In studies, plant extracts of caffeic acid and chlorogenic acid could inhibit the activities of CYP2C11 and CYP3A1 [45,46].…”

“…The dose of MLE was selected by the preliminary study. According to the literature [30], the dosage of MLE at a single dose of 600 mg/kg/day for 49 days was produced the antidiabetic effect and well-tolerated in animals. Blood samples were collected on 0, 2, 4, 6, 9, 12, 15, 18, 21, 22 days and the fasting glucose levels were measured.…”

A new high-performance liquid chromatographic method for the quality control of bioconverted Mori Folium extracts with appropriate marker compounds related to antidiabetes

“…Numerous studies have attempted to develop a functional food using MF and MF extracts (Liu et al 2009). Especially, our previous study proved enhanced antidiabetic activity of MF by bioconversion (Jung et al 2019).…”

Statistical Design of Sustained-Release Tablet Garcinia cambogia Extract and Bioconverted Mulberry Leaf Extract for Anti-Obesity

“…Bioconversion, such as microbial fermentation and enzyme treatment, has led to the improvement of bioactivity by enhancing the production of active ingredients. According to Jung et al, bioconverted MUL (BMUL) has improved the ability to decrease fasting blood glucose levels, tolerate glucose, decrease blood HbA1C levels, and increase plasma insulin compared with MUL [ 11 ]. Additionally, it has been reported that BMUL has shown antidiabetic effects in diabetic rats [ 12 ].…”