In vivo hypoglycaemic effect and inhibitory mechanism of the branch bark extract of the mulberry on STZ-induced diabetic mice

Anticancer and Neuroprotective Activities of Ethyl Acetate Fractions from Morus macroura Miq. Plant Organs with Ultraperformance Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry Profiling

Column chromatography afforded the isolation of seven secondary metabolites (1-(2,4,6-trihydroxy phenyl)-ethanone-4-O-β-d-glucopyranoside, naringenin-7-O-β-d-glucopyranoside, kaempferol-3-O-α-l-rhamnoside, kaempferol-3-O-β-d-glucopyranoside, quercetin-3-O-β-d-glucopyranoside, quercetin-3-O-β-d-galactopyranoside, rutin) from the ethyl acetate (ET) fractions of Morus macroura Miq. stems (S), leaves (L), and fruits (F). Their identification based on ultraviolet (UV), electron ionization (EI), electrospray ionization-mass spectrometry (ESI-MS), and 1D and 2D NMR data. In addition, profiling of ET fractions using ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) resulted in the identification of 82 compounds belonging to different classes, mainly polyphenolic constituents. Chemical profiling as well as molecular docking directed us to biological evaluation. Interestingly, the ET-L fraction exhibited a robust cytotoxic activity against HepG-2, MCF-7, and HELA cell lines. Also, it displayed a neuromodulatory activity against cisplatin neurotoxicity in rats by ameliorating the neurobehavioral dysfunction visualized in the open field and Y-maze test and modulating the neurochemical parameters such as brain amino acid levels (glutamate, aspartate, serine, and histidine), oxidative stress markers (GSH, MDA, and 8-hydroxy-2'-deoxyguanosine), and purinergic cell energy (adenosine triphosphate (ATP) and adenosine monophosphate (AMP)). In conclusion, the isolated compounds (kaempferol-3-O-β-glucoside and quercetin-3-O-β-glucoside) from the ET-L fraction could serve as potent anticancer agents due to their strong antioxidant, in vitro cytotoxicity, and in vivo neuroprotective activity.

Hydro-alcoholic extract of Morus nigra reduces fasting blood glucose and HbA1c% in diabetic patients, probably via competitive and allosteric interaction with alpha-glucosidase enzyme; a clinical trial and in silico analysis

OBJECTIVES

1-Deoxynojirimycin (1-DNJ), the main active component found in Morus nigra (black mulberry) is reported to be effective in controlling diabetes. We have evaluated the effect of hydro-alcoholic extract of M. nigra leaves on the fasting blood glucose (FBS) and hemoglobin A1c% (HbA1c%) in diabetic patients. Furthermore, we compared the interaction of 1-DNJ and glucose molecules with the alpha-glucosidase enzyme, which has a critical role in the lysis of glucose-based polymers in human cells.

METHODS

4% hydro-alcoholic extract was prepared from black mulberry leaves. Patients in treatment (n=50) and control (n=50) groups received 3 mL extract or placebo in water, respectively, and three times a day. Fasting blood glucose and HbA1c% were evaluated before and after three months of evaluation. Potential binding sites of 1-DNJ or glucose on the enzyme glucosidase found by docking study. Docking scores were obtained using an energy minimization method by Molegro Virtual Docker software. The Mean ± SD of each variable was compared between groups at the 95% significant level.

RESULTS

Age mean ± SD was equal to 54.79 ± 9.203 (38-69) years. There was no significant difference between intervention and placebo groups considering FBS (p=0.633) but was for HbA1c% (p=0.0011), before treatment. After three months, both FBS and HbA1c% were significantly reduced in patients under mulberry leaves extract-treatment. FBS changed was from 182.23 ± 38.65 to 161.23 ± 22.14 mg/dL in treatment group (p<0.001) and from 178.45 ± 39.46 to 166.23 ± 29.64 mg/dL in control group (p<0.001). HbA1c was changed from 7.23 ± 0.25 to 6.13 ± 0.61% in treatment group (p<0.001) and from 7.65 ± 0.85 to 7.12 ± 0.33% in control group (p=0.854). Docking results showed that 1-DNJ binds more efficiently, and with a significant score than glucose, to human alpha-glucosidase.

CONCLUSIONS

This clinical trial and virtual analysis showed that a hydro-alcoholic extract of black mulberry (M. nigra) leaf may be efficient in reducing the blood glucose and HbA1c% in diabetic patients. Furthermore, docking studies propose a competitive and allosteric regulation for herbal ingredients. Drug-development could be based on the presented idea in this report.

Significantly hypoglycemic effect of a novel functional bread rich in mulberry bark and improving the related functions of liver, pancreas, and kidney, on T2D mice

To develop a novel functional food with lowering blood glucose for diabetics, the mixed bread containing mulberry branch bark powder (MBBP) was used for the oral administration of the type 2 diabetic (T2D) mice induced by streptozocin (STZ), high-fat and high-sugar diet for 7 weeks. 5%, 10%, and 15% MBBP bread diets had a significatively positive influence on the biochemical indicators, histological examination, and immunohistochemistry observations in T2D mice. The 15% MBBP-rich bread diet evidently retarded loss weight of T2D mice, and decreased in FBG by about 55% and in glycosylated hemoglobin (HbA1c) levels by about 30%. Its glucose tolerance and serum insulin levels were very close to normal level. The abnormal lipid metabolism and insulin-related index of T2D mice in both the 10% and 15% MBBP bread diet groups were partly reversed. The Western blotting results showed that the expression levels of key proteins in PI3K/AKT signaling pathway were decreased and expression levels of immunoproteins PPARγ, TNF-α, P65, and IL6 were increased. In general, oral MBBP bread diets effectively restored some functions and repaired damage to the pancreas, liver, and kidney in T2D mice. Therefore, MBBP is potential to develop into a novel functional food additive with significantly hypoglycemic effect.

Mulberry Bark Alleviates Effect of STZ Inducing Diabetic Mice through Negatively Regulating FoxO1

Dysfunction of insulin secretion and hyperglycaemia were commonly found due to damaged β cells of pancreas. In our previous research, it was found that mulberry branch bark powder (MBBP) was effective in treating diabetes in mice which were induced by STZ and high fat diet. The present study was designed to evaluate the protective effect of MBBP on STZ-induced β cells injury and investigate underlying mechanisms. By preventive administration of branch bark powder, the damage caused by STZ injection was found to be alleviated. In MBBP feed groups, pathological weight loss was inhibited, fasting blood glucose was controlled, the incidence of diabetes decreased, and blood lipid level and antioxidant capacities were restored. The PI3K/AKT/FoxO1 signal pathway was found to be activated by key proteins expression and gene testing. In liver, the increased PI3K and phosphorylated AKT, the phosphorylated, and inactivated FoxO1, which regulates the expression of gluconeogenic gene and explains the effect of relieving insulin resistance of MBBP. Therefore, the MBBP improves the tolerance of pancreas to the toxicity of STZ involving the PI3K/AKT/FoxO1 signalling pathway.

Metabolic effects of mulberry branch bark powder on diabetic mice based on GC-MS metabolomics approach

BACKGROUND

Mulberry (Morus multicaulis) branch bark powder have showed effective hypoglycemic activity in our previous research. This study aims to explore the mechanism of protect effect on diabetes mice of mulberry branch bark as food supplement based on non-targeted GC-MS metabolomics' platform.

METHODS

Animal model of double diabetes was established with high fat diet and Streptozotocin injection. Mice were fed with mulberry branch bark powder (MBBP) for five weeks to study its therapeutic effect. The metabolite feature of diabetes model and treatment group mice were characterized using a gas chromatography-mass spectrometry-based metabolomics, complemented with the biochemical evaluation, histological inspection, immunohistochemistry observations and enzyme protein detection.

RESULTS

A panel of endogenous metabolites were revealed that are relevant to disturbed metabolic processes among groups. The serum metabolic profiles were significantly different between the model group and treatment group. The manner of MBBP treatment showed to be significantly dose dependent and 20% MBBP treatment gain a relatively greater benefit than others. The metabolic disorders in model group include enhanced activation of the sorbitol pathway and galactose metabolite, increased activities of gluconeogenesis, fatty acid oxidation, proteins catabolism and attenuated activities of pentose phosphate pathway, glycolysis and aerobic oxidation pathways, internal synthesis of cholesterol, inositol production. MBBP treatment ameliorate these abnormal metabolize as revealed by differential metabolites comparing with that of model mice, such as decreasing the accumulation of ketone body, enhancing NADPH biosynthesis, partially reversing oxidative stress and energy metabolism disturbance.

CONCLUSIONS

Mulberry branch bark had a re-balancing effect on the disturbed metabolic pathways in the diabetic mice. Based on the metabolic pathways network, oral administration of MBBP could ameliorate the hyperglycemia and hyperlipidemia symptoms in a global scale and restore the abnormal metabolic state to a near normal level in a dose dependent pattern.

Natural products, an important resource for discovery of multitarget drugs and functional food for regulation of hepatic glucose metabolism

Imbalanced hepatic glucose homeostasis is one of the critical pathologic events in the development of metabolic syndromes (MSs). Therefore, regulation of imbalanced hepatic glucose homeostasis is important in drug development for MS treatment. In this review, we discuss the major targets that regulate hepatic glucose homeostasis in human physiologic and pathophysiologic processes, involving hepatic glucose uptake, glycolysis and glycogen synthesis, and summarize their changes in MSs. Recent literature suggests the necessity of multitarget drugs in the management of MS disorder for regulation of imbalanced glucose homeostasis in both experimental models and MS patients. Here, we highlight the potential bioactive compounds from natural products with medicinal or health care values, and focus on polypharmacologic and multitarget natural products with effects on various signaling pathways in hepatic glucose metabolism. This review shows the advantage and feasibility of discovering multicompound-multitarget drugs from natural products, and providing a new perspective of ways on drug and functional food development for MSs.

Mulberry branch bark powder significantly improves hyperglycemia and regulates insulin secretion in type II diabetic mice

This experiment, based on the previous study on R. mori, introduces whole mulberry branch powder into the diet to treat diabetic mice. Mulberry branch bark powder (MBBP) was administered orally to streptozotocin (STZ)-induced type II diabetic (T2D) mice to investigate hypoglycemic effects. After a 4-week period of diet consumption containing 5%, 10% and 20% MBBP, the fasting blood glucose, body weight and the related western blotting were measured, pathologic and immunohistochemical were observed. The 20% MBBP group showed a significant reduction in hyperglycemia and hyperinsulinemia; fasting blood glucose and insulin decreased from 25.0 to 14.8 mmol/L and 26.5 to 16.0 mU/L, respectively. Pathologic and immunohistochemical observation showed that MBBP administration lead to the repair of pancreas cells and restoration of insulin secretion. Dietary MBBP was associated with the decrease in the contents of 3, 4-methylenedioxeamphetamine, 8-OHdG, aspartate aminotransferase, and alanine aminotransferase, and the increase in antioxidative ability and glucose tolerance. Western blotting (WB) analysis suggested that MBBP decreased the TNF-α levels, thus relieving inflammation and improving liver function. It also led to the downregulation of apoptosis factor expression. WB also confirmed that MBBP enhanced the gene expression of the key enzymes: insulin receptor, insulin receptor substrate, p-AKT, GSK3β, glycogen synthase, G6Pase and phosphoenolpyruvate carboxykinase, which are related to glucose metabolism in the liver, and increase the expression of the genes PDX-1, GLUT2, MafA, and glucokinase, related to insulin secretion. Thus, oral administration of MBBP regulated insulin secretion and effectively maintained normal levels of glucose metabolism in mice, which may be done by improving the antioxidant capacity and activating insulin signaling with T2D..

Mulberry leaf extract decreases digestion and absorption of starch in healthy subjects-A randomized, placebo-controlled, crossover study

PURPOSE

Mulberry (Morus alba L.) leaf tea has recently received much attention as a dietary supplement due to the wide range of putative health benefits, such as antidiabetic effects. Nevertheless, data evaluating its influence on carbohydrate metabolism in humans are scarce. The present study aims to investigate the effect of mulberry leaf extract supplementation on starch digestion and absorption in humans.

MATERIALS AND METHODS

The study comprised of 25 healthy subjects, aged 19-27 years. In all subjects, a starch ¹³C breath test was performed twice in a crossover and single blind design. Subjects were initially randomized to ingest naturally ¹³C-abundant cornflakes (50g cornflakes+100ml low fat milk) either with the mulberry leaf extract (36mg of active component-1-deoxynojirimycin) or the placebo and each subject received the opposite preparation one week later.

RESULTS

The cumulative percentage dose recovery was lower for the mulberry leaf extract test than for the placebo test (median [quartile distribution]: 13.9% [9.9-17.4] vs. 17.2% [13.3-20.6]; p=0.015). A significant decrease was detectable from minute 120 after the ingestion.

CONCLUSIONS

A single dose of mulberry leaf extract taken with a test meal decreases starch digestion and absorption. These findings could possibly be translated into everyday practice for improvement of postprandial glycemic control.

Evaluation of the Antidiabetic Properties of S-1708 Mulberry Variety

Background:

Diabetes is a metabolic disease prevalent worldwide in all age group of people. The source of diabetes is due to an oxidation process that can produce free radicals. An increase in oxidative free radicals in the body is reported to be one of the several causes of diabetes. The best remedy to combat oxidative stress is the use of antioxidants, which inhibit and scavenge free radicals.

Aim:

This study has been undertaken to evaluate the antioxidant activity and antidiabetic effect of mulberry leaf extract in diabetic mice.

Materials and Methods:

Antioxidant activity of mulberry leaves was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assay. Antidiabetic assay of mulberry leaf extract was analyzed by oral administration of leaf extract up to 3 weeks in diabetic mice induced by streptozotocin.

Results:

In vitro antioxidant activity in both DPPH and FRAP assays showed significantly (P < 0.05) higher inhibition of free radicals than that with ascorbic acid. Diabetic mice fed with mulberry leaf extract showed increment (+25.88%) in body weight and a significant reduction in blood glucose concentration (−71.58%). Further, glucose-6-phosphate dehydrogenase enzyme activity was significantly (P < 0.05) increased, whereas activities of other enzymes particularly catalase, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase were decreased in diabetic mice after oral administration of mulberry leaf extracts. Histology of liver revealed regeneration of hepatocytes, central vein, and nucleus.

Conclusion:

This study demonstrated that S-1708 mulberry variety has a potential therapeutic value in diabetes and related complications.

SUMMARY

Diabetes mellitus is a grave metabolic deviations and responsible for many complications affecting various organs in the human body. In spite of the known antidiabetic medicine available in the market, diabetes and the associated impediments sustained to be a major medical crisis. Medicinal plants have been proven to be useful in diabetes due to their rich therapeutic value. In the current study, S-1708 mulberry variety not only authenticated the earlier results obtained from other medicinal plants but also turn out to be known as a potential source for treating diabetes by demonstrating tremendous ant- diabetic properties.

Abbreviations used: S-1708, DPPH, FRAP.

Interference effect of oral administration of mulberry branch bark powder on the incidence of type II diabetes in mice induced by streptozotocin

Background

Diabetes is a group of metabolic diseases that has become a global health problem worldwide. Many researchers have found that mulberry branches have a hypoglycemic effect, but there have been few studies or investigations regarding the use of mulberry branches to prevent the incidence of diabetes.

Objective

This study aimed to investigate the potential preventive effect of mulberry branch bark powder (MBBP) from Morus multicaulis L against type II diabetes in mice induced by streptozotocin (STZ).

Design

The normal mice were fed a diet containing 2.5, 5.0, and 10.0%, MBBP, respectively, for 2 weeks. After that, STZ (100 mg/kg) was injected into the caudal vein of these mice. These mice continued to be fed the same diet, and the fasting blood glucose (FBG) levels were monitored on the 17th and 21st days.

Results

Oral administration of MBBP could effectively inhibit weight loss and maintain the FBG level. The incidence of diabetes in mice was almost inhibited by treatment with 10% MBBP. MBBP could also maintain the original antioxidant capacity and regulate the lipid metabolism in mice. An immunohistochemical assay showed that MBBP could prevent the injury of the insulin-secreting islet beta cells induced by STZ. RT-PCR also confirmed that the mRNA expression of the genes PI3K, Pdk1, Akt, and FoxO1, which were involved in the PI3K/Akt signaling pathway, hardly suffered from STZ in the 10% MBBP-dose group.

Conclusions

Our results indicate that powdered mulberry branch bark has a powerful anti-diabetic effect. These results clearly illustrated that MBBP has a potential use as a health food additive in the prevention of diabetes.

1-Deoxynojirimycin Alleviates Liver Injury and Improves Hepatic Glucose Metabolism in db/db Mice

The present study investigated the effect of 1-Deoxynojirimycin (DNJ) on liver injury and hepatic glucose metabolism in db/db mice. Mice were divided into five groups: normal control, db/db control, DNJ-20 (DNJ 20 mg·kg⁻¹·day⁻¹), DNJ-40 (DNJ 40 mg·kg⁻¹·day⁻¹) and DNJ-80 (DNJ 80 mg·kg⁻¹·day⁻¹). All doses were treated intravenously by tail vein for four weeks. DNJ was observed to significantly reduce the levels of serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and liver TG, as well as activities of serum alanine aminotransferase (ALT), and aspartate transaminase (AST); DNJ also alleviated macrovesicular steatosis and decreased tumor necrosis factor α (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6) levels in liver tissue. Furthermore, DNJ treatment significantly increased hepatic glycogen content, the activities of hexokinase (HK), pyruvate kinase (PK) in liver tissue, and decreased the activities of glucose-6-phosphatase (G6Pase), glycogen phosphorylase (GP), and phosphoenolpyruvate carboxykinase (PEPCK). Moreover, DNJ increased the phosphorylation of phosphatidylinositol 3 kinase (PI3K) on p85, protein kinase B (PKB) on Ser473, glycogen synthase kinase 3β (GSK-3β) on Ser9, and inhibited phosphorylation of glycogen synthase (GS) on Ser645 in liver tissue of db/db mice. These results demonstrate that DNJ can increase hepatic insulin sensitivity via strengthening of the insulin-stimulated PKB/GSK-3β signal pathway and by modulating glucose metabolic enzymes in db/db mice. Moreover, DNJ also can improve lipid homeostasis and attenuate hepatic steatosis in db/db mice.