Hybrid of 1-deoxynojirimycin and polysaccharide from mulberry leaves treat diabetes mellitus by activating PDX-1/insulin-1 signaling pathway and regulating the expression of glucokinase, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase in alloxan-induced diabetic mice

Biosynthesis and Pharmacological Activities of the Bioactive Compounds of White Mulberry (Morus alba): Current Paradigms and Future Challenges

Traditional natural products have been the focus of research to explore their medicinal properties. One such medicinally important plant is the white mulberry, Morus alba, widely distributed in the Asian subcontinent. It is one of the most cultivated species of mulberry tree and has attracted more focus from researchers because of its abundance in phytochemicals as well as multipurpose uses. The leaves, fruits and other parts of the white mulberry plant act as a source of valuable bioactive compounds like flavonoids, phenolic acids, terpenoids and alkaloids. These secondary metabolites have manifold healthy uses as they possess antioxidant, anti-inflammatory, antidiabetic, neutrotrophic, and anticancer properties. Despite the increasing scientific interest in this plant, there are very few reviews that highlight the phytochemistry and biological potential of white mulberry for biomedical research. To this end, this review elaborates the phytochemistry, biosynthetic pathways and pharmacological activities of the glycoside flavonoids of Morus alba. A comprehensive analysis of the available literature indicates that Morus alba could emerge as a promising natural agent to combat diverse conditions including diabetes, cancer, inflammation and infectious diseases. To achieve such important objectives, it is crucial to elucidate the biosynthesis and regulation mechanisms of the bioactive compounds in white mulberry as well as the multifaceted pharmacological effects attributed to this plant resource. The present review paper is intended to present a summary of existing scientific data and a guide for further research in the phytochemistry and pharmacology of white mulberry. Further, a biosynthetic pathway analysis of the glycoside flavonoid in mulberry is also given. Lastly, we discuss the pros and cons of the current research to ensure the prudent and effective therapeutic value of mulberry for promoting human and animal health.

Mining and functional characterization of NADPH-cytochrome P450 reductases of the DNJ biosynthetic pathway in mulberry leaves

BACKGROUND

1-Deoxynojirimycin (DNJ), the main active ingredient in mulberry leaves, with wide applications in the medicine and food industries due to its significant functions in lowering blood sugar, and lipids, and combating viral infections. Cytochrome P450 is a key enzyme for DNJ biosynthesis, its activity depends on the electron supply of NADPH-cytochrome P450 reductases (CPRs). However, the gene for MaCPRs in mulberry leaves remains unknown.

RESULTS

In this study, we successfully cloned and functionally characterized two key genes, MaCPR1 and MaCPR2, based on the transcriptional profile of mulberry leaves. The MaCPR1 gene comprised 2064 bp, with its open reading frame (ORF) encoding 687 amino acids. The MaCPR2 gene comprised 2148 bp, and its ORF encoding 715 amino acids. The phylogenetic tree indicates that MaCPR1 and MaCPR2 belong to Class I and Class II, respectively. In vitro, we found that the recombinant enzymes MaCPR2 protein could reduce cytochrome c and ferricyanide using NADPH as an electron donor, while MaCPR1 did not. In yeast, heterologous co-expression indicates that MaCPR2 delivers electrons to MaC3'H hydroxylase, a key enzyme catalyzing the production of chlorogenic acid from 3-O-p-coumaroylquinic acid.

CONCLUSIONS

These findings highlight the orchestration of hydroxylation process mediated by MaCPR2 during the biosynthesis of secondary metabolite biosynthesis in mulberry leaves. These results provided a foundational understanding for fully elucidating the DNJ biosynthetic pathway within mulberry leaves.

Glucose-lowering effect of Reducose® enriched with 1-deoxynojirimycin and l-leucine: Studies on insulin secretion in INS-1 cells and reduction of blood glucose in diabetic rats

The extract of mulberry leaf and its active ingredients have already been reported to have anti-diabetic effects; however, further studies are required to obtain better quality extracts and higher yields of active ingredients. Reducose® is a commercially available aqueous extract of mulberry leaves with a high content of active ingredients. In this study, the biological activities of Reducose®, 1-deoxynojirimycin, and l-leucine were evaluated using a glucose-stimulated insulin secretion (GSIS) assay. The GSIS assay results were expressed as the glucose-stimulated index (GSI). Considering the pharmacological safety in pancreatic β-cells, the appropriate non-toxic concentrations were selected by screening for cytotoxicity of Reducose®, 1-deoxynojirimycin, and l-leucine before the GSIS assay. The effect of Reducose®, 1-deoxynojirimycin, and l-leucine on glucose-stimulated insulin secretion in INS-1 cells was compared. Reducose®, 1-deoxynojirimycin, and l-leucine increased the GSI values more effectively than gliclazide (positive control). This was associated with an increase in protein expression, such as peroxisome proliferator-activated receptor-γ, insulin receptor substrate-2, activated pancreatic and duodenal homeobox-1, which are related to the regulation of pancreatic β-cell function and survival. In order to elucidate the effect of Reducose® in anti-diabetic effects, blood glucose levels, insulin levels, and liver and lipid concentrations were investigated in a Sprague-Dawley rat model of high-fat diet/streptozotocin-induced diabetes. We observed that administration of Reducose® can decrease fasting blood glucose levels and reduce the production of AST, ALT, TG, and TC to a similar extent as metformin (positive control). These results suggested that Reducose® play a role in promoting GSIS but not enough to show that the content and proportion of 1-deoxynojirimycin and l-leucine play an important role in the GSIS activity of Reducose®.

Hypoglycemic effect of Lactobacillus plantarum-fermented mulberry pomace extract in vitro and in Caenorhabditis elegans

Mulberry pomace is rich in phytochemicals, but there are few studies on its utilization as a by-product. Natural foods containing phytochemicals can alleviate the toxic effects of excessive glucose intake. In this study, we investigated the protective effect of Lactobacillus plantarum-fermented mulberry pomace extract (FMPE) under hyperglycemic conditions. The phenolic compounds and α-glucosidase inhibition of FMPE were determined using UPLC-MS and chemical models. Furthermore, Caenorhabditis elegans was a model system to study the hypoglycemic effects. The results showed that the polyphenolics and α-glucosidase inhibition were improved during fermentation. Three phenolic components (cyanidin, 2,4,6-trihydroxybenzaldehyde, and taxifolin) were important variables for α-glucosidase inhibition. FMPE and the three key compound treatments reduced the glucose content and reactive oxygen species (ROS) level in Caenorhabditis elegans. The protective mechanism occurred by activating DAF-16/FOXO and SKN-1/Nrf2. This study suggests that Lactobacillus plantarum-fermentation was a potential way to utilize mulberry pomace polyphenols as hypoglycemic food ingredients.

Effects and Mechanistic Role of Mulberry Leaves in Treating Diabetes and its Complications

Diabetes mellitus (DM) has become a surge burden worldwide owing to its high prevalence and range of associated complications such as coronary artery disease, blindness, stroke, and renal failure. Accordingly, the treatment and management of DM have become a research hotspot. Mulberry leaves (Morus alba L.) have been used in Traditional Chinese Medicine for a long time, with the first record of its use published in Shennong Bencao Jing (Shennong's Classic of Materia Medica). Mulberry leaves (MLs) are considered highly valuable medicinal food homologs that contain polysaccharides, flavonoids, alkaloids, and other bioactive substances. Modern pharmacological studies have shown that MLs have multiple bioactive effects, including hypolipidemic, hypoglycemic, antioxidation, and anti-inflammatory properties, with the ability to protect islet [Formula: see text]-cells, alleviate insulin resistance, and regulate intestinal flora. However, the pharmacological mechanisms of MLs in DM have not been fully elucidated. In this review, we summarize the botanical characterization, traditional use, chemical constituents, pharmacokinetics, and toxicology of MLs, and highlight the mechanisms involved in treating DM and its complications. This review can provide a valuable reference for the further development and utilization of MLs in the prevention and treatment of DM.

Clinical potential and mechanistic insights of mulberry (Morus alba L.) leaves in managing type 2 diabetes mellitus: Focusing on gut microbiota, inflammation, and metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Natural herbs are gradually gaining recognition for their efficacy and safety in preventing diabetes and improving quality of life. Morus alba L. is a plant widely grown in Asia and is a traditional Chinese herb with a long history of use. Furthermore, several parts of Morus alba L. have been found to have significant health benefits. In particular, mulberry (Morus alba L.) leaves (ML) have been shown in human and animal studies to be promising hypoglycemic agents that can reduce or prevent glucolipid metabolism disorders caused by imbalances in the gut microbiota, inflammation, and oxidative stress and have demonstrated significant improvements in glucose metabolism-related markers, effectively lowering blood glucose, and reducing hyperglycemia-induced target organ damage.

AIM OF THE STUDY

This review briefly summarizes the methods for obtaining ML's bioactive components, elaborates on the clinical potential of the relevant components in managing type 2 diabetes mellitus (T2DM), and focuses on the therapeutic mechanisms of gut microbiota, inflammation, oxidative stress, and metabolism, to provide more inspiration and directions for future research in the field of traditional natural plants for the management of T2DM and its complications.

MATERIALS AND METHODS

Research on ML and its bioactive components was mainly performed using electronic databases, including PubMed, Google Scholar, and ScienceNet, to ensure the review's quality. In addition, master's and doctoral theses and ancient documents were consulted.

RESULTS

In clinical studies, we found that ML could effectively reduce blood glucose, glycated hemoglobin, and homeostasis model assessment of insulin resistance in T2DM patients. Furthermore, many in vitro and in vivo experiments have found that ML is involved in various pathways that regulate glucolipid metabolism and resist diabetes while alleviating liver and kidney damage.

CONCLUSIONS

As a potential natural anti-diabetic phytomedicine, an in-depth study of ML can provide new ideas and valuable references for applying traditional Chinese medicine to treat T2DM. While continuously exploring its clinical efficacy and therapeutic mechanism, the extraction method should be optimized to improve the efficacy of the bioactive components. in addition, further research on the dose-response relationship of drugs to determine the effective dose range is required.

Managing metabolic diseases: The roles and therapeutic prospects of herb-derived polysaccharides

Metabolic diseases have become a public health problem worldwide. Effective, novel and natural therapies are urgently needed to treat metabolic diseases. As natural bioactive compounds, polysaccharides have many physiological and medicinal properties. Recently, herb-derived polysaccharides have shown beneficial effects in the treatment of metabolic diseases, but the underlying mechanisms remain unclear. This review comprehensively summarizes the pharmacological progress and clinical evidence of herb-derived polysaccharides in the treatment of three metabolic diseases, namely type 2 diabetes mellitus, nonalcoholic fatty liver disease and obesity, and more importantly, discusses the molecular mechanism involved. Existing evidence has proved that herb-derived polysaccharides can maintain glucose homeostasis, promote insulin secretion, improve insulin resistance, reduce weight gain and hepatic steatosis, inhibit lipogenesis, alleviate oxidative stress and inflammation, and improve gut microbiota disorders in rodents with metabolic diseases. Notably, so far, human clinical trials of herb-derived polysaccharides for these three metabolic diseases remain rare. All in all, herb-derived polysaccharides may have good potential as drug candidates for the prevention and management of metabolic diseases. More high-quality clinical trials are needed to further validate its effectiveness and safety in human subjects.

Effects of the timing of acute mulberry leaf extract intake on postprandial glucose metabolism in healthy adults: a randomised, placebo-controlled, double-blind study

BACKGROUND/OBJECTIVES

Glucose tolerance is controlled by the internal clock and is worse in the evening. From a chrononutrition perspective, diabetes prevention requires evaluating the antidiabetic effects of the timing of functional ingredients and nutrient intake. The purpose of this study was to investigate the timing effects of acute mulberry leaf extract (MLE) intake on postprandial glucose levels in young adults.

SUBJECTS/METHODS

Twelve young adults underwent four trials. Blood samples were collected in a fasting state and at 30, 60, 120, and 180 min after eating a mixed meal. The study had a randomised, placebo-controlled, double-blind trial design involving: (1) morning placebo trial (08:00 h; MP trial), (2) evening placebo trial (18:00 h; EP trial), (3) morning MLE trial (08:00 h; MM trial), and (4) evening MLE trial (18:00 h; EM trial).

RESULTS

The incremental area under the blood glucose curve (iAUC) in the EM trials was significantly lower than that in the EP trials (P = 0.010). The postprandial glucose concentrations 120 min after the meal were significantly lower in the EM trials than those in the EP trials (P = 0.006). The postprandial insulin concentrations at 120 min were significantly lower in the MM trials than those in the MP trials (P = 0.034). Moreover, the postprandial insulin concentrations 180 min after the meal were significantly lower in the EM trials than those in the EP trials (P = 0.034).

CONCLUSIONS

MLE intake in the evening, but not in the morning, was effective in improving glucose tolerance.

TRIAL REGISTRATION

Clinical trial reference: UMIN 000045301; website of trial registry: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000051340 .

Chalcone-1-Deoxynojirimycin Heterozygote Reduced the Blood Glucose Concentration and Alleviated the Adverse Symptoms and Intestinal Flora Disorder of Diabetes Mellitus Rats

Chalcone-1-deoxynojirimycin heterozygote (DC-5), a novel compound which was designed and synthesized in our laboratory for diabetes treatment, showed an extremely strong in vitro inhibitory activity on α-glucosidase in our previous studies. In the current research, its potential in vivo anti-diabetic effects were further investigated by integration detection and the analysis of blood glucose concentration, blood biochemical parameters, tissue section and gut microbiota of the diabetic rats. The results indicated that oral administration of DC-5 significantly reduced the fasting blood glucose and postprandial blood glucose, both in diabetic and normal rats; meanwhile, it alleviated the adverse symptoms of elevated blood lipid level and lipid metabolism disorder in diabetic rats. Furthermore, DC-5 effectively decreased the organ coefficient and alleviated the pathological changes of the liver, kidney and small intestine of the diabetic rats at the same time. Moreover, the results of 16S rDNA gene sequencing analysis suggested that DC-5 significantly increased the ratio of Firmicutes to Bacteroidetes and improved the disorder of gut microbiota in diabetic rats. In conclusion, DC-5 displayed a good therapeutic effect on the diabetic rats, and therefore had a good application prospect in hypoglycemic drugs and foods.

Molecular cloning, expression, and functional analysis of copper amine oxidase gene from mulberry (Morus alba L.)

In this study, we investigated a key enzyme encoded by the gene copper amine oxidase (MaCAO), which is involved in the biosynthetic pathway of 1-deoxynojirimycin (DNJ)¹, an active ingredient in mulberry leaves. The 1680 bp long MaCAO was successfully cloned (GenBank accession no: MH205733). Subsequently, MaCAO was heterologously expressed using a recombinant plasmid, pET-22b (+)/MaCAO in Escherichia coli BL21 (DE3). A protein with a molecular mass of 62.9 kDa was obtained, whose function was validated through enzymatic reaction. Bioinformatics analysis identified that MaCAO contained the same conserved domain as that of copper amine oxidases ("NYDY"). Furthermore, the tertiary structure of the predicted protein using homology modeling revealed 46% similarity with that of copper amine oxidase (Protein Data Bank ID: 1W2Z). Gas chromatography-mass spectrometry analysis of the enzymatic reaction revealed that MaCAO could catalyze 1,5-pentanediamine to produce 5-aminopentanal. Additionally, levels of mulberry leaf DNJ content were significantly positively correlated with expression levels of MaCAO (P < 0.001). Our results conclude that MaCAO is the key enzyme involved in the biosynthetic pathway of DNJ. The function of MaCAO is validated, providing a foundation for the further analysis of biosynthetic pathways of DNJ in mulberry leaves using tools of synthetic biology.

1-Deoxynojirimycin attenuates septic cardiomyopathy by regulating oxidative stress, apoptosis, and inflammation via the JAK2/STAT6 signaling pathway

Cardiac dysfunction caused by sepsis is the predominant reason for death in patients with sepsis. However, the effective drugs for its prevention and the molecular mechanisms remain elusive. 1-Deoxynojirimycin (DNJ), a natural iminopyranose, exhibits various biological properties, such as hypoglycemic, antitumor, antiviral, and anti-inflammatory activities. However, whether DNJ can mediate biological activity resistance in sepsis-induced myocardial injury and the underlying mechanisms are unclear. Janus kinase and signal transducer and activator of transcription (JAK/STAT) signaling is an important pathway for the signal transduction of several key cytokines in the pathogenesis of sepsis, which can transcribe and modulate the host immune response. This study was conducted to confirm whether DNJ mediates oxidative stress, apoptosis, and inflammation in cardiomyocytes, thereby alleviating myocardial injury in sepsis via the JAK2/STAT6 signaling pathway. Septic cardiomyopathy was induced in mice using lipopolysaccharide (LPS), and they were then treated with DNJ. The results showed that DNJ markedly improved sepsis-induced cardiac dysfunction, attenuated reactive oxygen species generation, reduced cardiomyocyte apoptosis, and mitigated inflammation. Mechanistically, increased JAK2/STAT6 phosphorylation was observed in the mouse sepsis models, which decreased significantly after DNJ oral treatment. To further confirm whether DNJ mediates the JAK2/STAT6 pathway, the selective inhibitor fedratinib was used to block the JAK2 signaling pathway in vitro, which enhanced the protective effects of DNJ against the sepsis-induced cardiac damage. Collectively, these findings suggest that DNJ attenuates sepsis-induced myocardial injury by decreasing myocardial oxidative damage, apoptosis, and inflammation via the regulation of the JAK2/STAT6 signaling pathway.

Combination of mulberry leaf active components possessed synergetic effect on SD rats with diabetic nephropathy by mediating metabolism, Wnt/β-catenin and TGF-β/Smads signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Mulberry leaf has attracted much attention due to its excellent curative effect on diabetes and its complications, whether the combination of its effective components have protective and synergistic effect on diabetic nephropathy (DN) in vivo remain unclear.

AIM OF THE STUDY

The aim of this study was to investigate the protective and synergistic effect of the combination (MAF_1:1 and MAF_1:5) of mulberry leaf alkaloids (MA) and flavonoids extract (MF) on DN.

MATERIALS AND METHODS

A step by step method consisted of network pharmacological prediction, animal in vivo validation and metabolic mechanism research was used to construct the multi-component-target-pathway network of mulberry leaf against DN. Firstly, the potential components and mechanism of mulberry leaf against DN was explored by network pharmacology analysis. Secondly, DN animal model was established to validate the anti-DN activity of these potential compounds. Thirdly, the metabolomics of serum and urine samples from animal experiments was analyzed to explore the anti-DN mechanism of these potential compounds.

RESULTS

The results of network pharmacology demonstrated that a total of 7 compounds detected in MA and MF exhibited anti-DN activity, their mechanism were strongly in connection with metabolic pathways, arachidonic acid metabolism, sphingolipid signaling pathway, etc. The results of animal experiment indicated that MAF_1:1 and MAF_1:5 significantly relieved metabolic disorders through regulating Wnt/β-catenin and TGF-β/Smads signaling pathway, just like MF or MA alone. Metabolomics suggested they could regulate 16 serum and 7 urine endogenous metabolites through arachidonic acid metabolism, phenylalanine metabolism and sphingolipid metabolism, thus alleviated DN. Significantly, MAF_1:1 and MAF_1:5 might possess synergistic effect considering their therapeutic effects on DN rats were superior to the single use of MA or MF.

CONCLUSIONS

MAF_1:1 and MAF_1:5 possessed protective and synergistic effect on DN rats through multi-target and multi-pathways. These findings were of great scientific significance and application value to reveal the advantage of mulberry leaf in preventing and treating DN.

Mulberry (Morus alba L.) leaf polysaccharide ameliorates insulin resistance- and adipose deposition-associated gut microbiota and lipid metabolites in high-fat diet-induced obese mice

Dietary supplements are currently being used to ameliorate metabolic alterations via maintaining gut microflora balance. Mulberry leaf is known as medicine homologous food for its glucose- and lipid-modulating properties. However, the effects of mulberry leaf polysaccharide (MP) on metabolic dysbiosis and gut microbiota are still poorly understood. After extraction and characterization, the beneficial effects of water-soluble MP were evaluated in high-fat diet-induced obese mice. MP treatment could reduce adipose tissue, improve insulin resistance, and alleviate the pathological lesions in colon. Investigation of the underlying mechanism showed that MP modulated gut microbial community by 16S rRNA analysis and reversed the elevation of lipid indexes by plasma lipidomics analysis. Correlation analysis indicated that the abundance of seven key bacterial species and six lipids were closely associated with the metabolic traits, respectively. Overall, MP could ameliorate metabolic disorders, and modify the gut microbiota and lipids. This would greatly facilitate the utilization of MP as a functional food.

Mulberry leaves ameliorate diabetes via regulating metabolic profiling and AGEs/RAGE and p38 MAPK/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Mulberry leaves have been used as traditional hypoglycemic medicine-food plant for thousand years in China. According to traditional Chinese medicine theory, type 2 diabetes mellitus (T2DM) belongs to the category of XiaoKe. Presently, the research of mulberry leaf hypoglycemic and lipid-lowering direction is mature, but the curative effects of alkaloids, flavonoids, polysaccharides, and other bioactive ingredients and the related mechanism is still unclear.

AIM OF THE STUDY

This paper aims to study the efficacy and mechanism of alkaloids, flavonoids, polysaccharides, and other bioactive components in mulberry leaves in the treatment of T2DM individually.

MATERIALS AND METHODS

The determination of levels of fasting blood glucose (FBG), triglyceride (TG) and total cholesterol (T-Cho), and pyruvate kinase (PK), hexokinase (HK), and alanine aminotransferase (ALT/GPT) of in plasma of diabetic mice. Urine metabolomics was analyzed by UPLC-QTOF/MS to evaluate differential metabolites from multiple metabolic pathways. The glucose uptake of HepG2 cells and 3T3-L1 cells. Expression of Caspase-3 and caspase-9, inflammatory injury and p38MAPK/NF-κB signaling pathway in GLUTag cells.

RESULTS

Our study revealed alkaloids, flavonoids, and polysaccharides in mulberry leaf could increase the levels of PK, HK, and ALT/GPT, and decrease the levels of TG and T-Cho significantly, and regulate glucose, amino acid, and lipid metabolism. Furthermore, 1-deoxynojirimycin (DNJ) and isoquercitrin (QG) both could increase glucose uptake and promote differentiation of HepG2 cells, increase PPARγ, C/EBPα and SREBP-l expression in 3T3-L1 cells, and inhibit AGEs-induced injury and apoptosis in GLUTag cells, reduce the expression of proteins related to AGEs/RAGE and p38MAPK/NF-κB pathway. Notably, isoquercitrin exhibited more pronounced anti-diabetic efficacy.

CONCLUSIONS

The alkaloids, flavonoids, and polysaccharides from mulberry leaf exhibited hypoglycemic activity through the regulation of glucose, amino acid, and lipid metabolism. 1-DNJ and QG increased glucose uptake and promoted differentiation of HepG2 cells, increased PPARγ, C/EBPα and SREBP-l expression in 3T3-L1 cells, and inhibited AGEs-induced injury and apoptosis in GLUTag cells via the AGEs/RAGE and p38 MAPK/NF-κB pathway.

Hepatoprotective effect of different mulberry leaf extracts against acute liver injury in rats by alleviating oxidative stress and inflammatory response

This study investigated the hepatoprotective effect of various mulberry (Morus alba L.) leaf extracts (MLEs), including mulberry ethanol extract (MEE), aqueous extract (MAE) and combination extract (MCE) against D-galactosamine (D-GalN)...

Aloe vera carbohydrates regulate glucose metabolism through improved glycogen synthesis and downregulation of hepatic gluconeogenesis in diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe vera (L.) Burm.f. is an ancient medicinal plant that belongs to the family Asphodelaceae. It has a rich source of bioactive constituents such as carbohydrates, polyphenols, peptides, sterols and tannins, etc. Aloe vera has multiple biological activities such as anti-inflammatory, antioxidant and antidiabetic activity etc. AIM OF THE STUDY: The present study investigated the antidiabetic mechanism of Aloe vera carbohydrate fraction (AVCF) and aimed to provide insights into the regulation of carbohydrate metabolism enzymes in glucose homeostasis.

MATERIALS AND METHODS

The antidiabetic effect of AVCF was evaluated using α-amylase, α-glucosidase inhibition, glucose diffusion and glucose uptake assay. The in vitro AVCF effect on insulin secretion, cell proliferation and inflammatory markers were determined using streptozotocin-induced oxidative stress on RIN-m5F cells. Streptozotocin-induced male Wistar diabetic rats were treated for 21 days with AVCF (54 mg/kg bw). The in vivo AVCF effect was measured on fasting plasma glucose, insulin, glucagon, hexokinase, glycogen synthase and glucose-6-phosphatase, levels in diabetic rats. Histopathological studies for organ-specific effects in the pancreas, liver and small intestine were also conducted.

RESULTS

AVCF-treated RIN-m5F cells significantly increased BrdU levels, with insulin secretion, and decreased TNF-α, IL-6 and nitric oxide levels. AVCF treated streptozotocin-induced diabetic rats showed significantly decreased fasting plasma glucose, glucagon and glucose-6-phosphatase levels with a concomitant increase in insulin, hexokinase, and glycogen synthase levels and, glycogen content. These findings corroborate with the improved hepatic glycogen content in the PAS stained histological section of the liver of AVCF treated diabetic rats.

CONCLUSION

These results suggest that CF of Aloe vera improved glucose metabolism by activation of glycogenesis and down-regulation of gluconeogenesis thereby, maintaining glucose homeostasis. Hence, AVCF can be used as an alternative medicine in the alleviation of diabetes mellitus symptoms.

Pharmacological Investigations in Traditional Utilization of Alhagi maurorum Medik. in Saharan Algeria: In Vitro Study of Anti-Inflammatory and Antihyperglycemic Activities of Water-Soluble Polysaccharides Extracted from the Seeds

The anti-inflammatory and antihyperglycemic effects of polysaccharides extracted from Alhagi&nbsp;maurorum Medik. seeds, spontaneous shrub collected in Southern of Algerian Sahara were investigated. Their water extraction followed by alcoholic precipitation was conducted to obtain two water-soluble polysaccharides extracts (WSPAM1 and WSPAM2). They were characterized using Fourier transform infrared, ¹H/¹³C Nuclear Magnetic Resonance, Gas Chromatography-Mass Spectrometry and Size Exclusion Chromatography coupled with Multi-Angle Light Scattering. The capacity of those fractions to inhibit α-amylase activity and thermally induced Bovine Serum Albumin denaturation were also investigated. WSPAM1 and WSPAM2 were galactomannans with a mannose/galactose ratio of 2.2 and 2.4, respectively. The SEC-MALLS analysis revealed that WSPAM1 had a molecular weight of 1.4 × 10⁶ Da. The investigations highlighted antinflammatory and antihyperglycemic effects in a dose-dependant manner of WSPAM1 and WSPAM2.

A comprehensive review on the production, pharmacokinetics and health benefits of mulberry leaf iminosugars: Main focus on 1-deoxynojirimycin, d-fagomine, and 2-O-ɑ-d-galactopyranosyl-DNJ

Mulberry leaves are rich in biologically active compounds, including phenolics, polysaccharides, and alkaloids. Mulberry leaf iminosugars (MLIs; a type of polyhydroxylated alkaloids), in particular, have been gaining increasing attention due to their health-promoting effects, including anti-diabetic, anti-obesity, anti-hyperglycemic, anti-hypercholesterolemic, anti-inflammatory, and gut microbiota-modulatory activities. Knowledge regarding the in vivo bioavailability and bioactivity of MLIs are crucial to understand their role and function and human health. Therefore, this review is aimed to comprehensively summarize the existing studies on the oral pharmacokinetics and the physiological significance of selected MLIs (i.e.,1-deoxynojirimycin, d-fagomine, and 2-O-ɑ-d-galactopyranosyl-DNJ). Evidence have suggested that MLIs possess relatively good uptake and safety profiles, which support their prospective use for oral intake; the therapeutic potential of these compounds against metabolic and chronic disorders and the underlying mechanisms behind these effects have also been studied in in vitro and in vivo models. Also discussed are the biosynthetic pathways of MLIs in plants, as well as the agronomic and processing factors that affect their concentration in mulberry leaves-derived products.

Recent advances on bioactive polysaccharides from mulberry

Mulberry (Moraceae family), commonly considered as a folk remedy, has a long history of usage in many regions of the world. Polysaccharides regarded as one of the major components in mulberry plants, and they possess antioxidant, antidiabetic, hepatoprotective, prebiotic, immunomodulatory and antitumor properties, among others. In recent decades, mulberry polysaccharides have been widely studied for their multiple health benefits and potential economic value. However, there are few reviews providing updated information on polysaccharides from mulberry. In this review, recent advances in the study of isolation, purification, structural characterization, biological activity and the structure-activity relationship of mulberry polysaccharides are summarized and discussed. Furthermore, a thorough analysis of the current trends and perspectives on mulberry polysaccharides is also proposed. Hopefully, these findings can provide a useful reference value for the development and application of natural polysaccharides in the field of functional food and medicine in the future.

Nutritional constituents of mulberry and their potential applications in food and pharmaceuticals: A review

Mulberry is a fast growing deciduous plant found in wide variety of climatic, topographical and soil conditions, and is widely distributed from temperate to subtropical regions. Due to presence of valuable phytochemical constituents, mulberry as a whole plant has been utilized as a functional food since long time. Mulberry fruits are difficult to preserve as they have relatively high water content. Therefore for proper utilization, different value-added products like syrups, squashes, teas, pestil sand köme, pekmez (turkuish by-products), yogurts, jams, jellies, wines, vinegar, breads, biscuits, parathas, and many more are made. In overseas, these value-added products are commercially sold and easily available, though in India, this versatile medicinal plant is still missing its identity at commercial and industrial scale. Leaves of mulberry are economically viable due to their important role in the sericulture industry since ancient times. Mulberries or its extracts exhibit excellent anti-microbial, anti-hyperglycaemic, anti-hyperlipidemic, anti-inflammatory, anti-cancer effects and is used to combat different acute and chronic diseases. Different parts of Morus species like fruits, leaves, twigs, and bark exhibit strong anti-tyrosinase inhibition activity that makes it a suitable candidate in cosmetic industries as a whitening agent. The current review provides a comprehensive discussion concerning the phytochemical constituents, functionality and nutraceutical potential of mulberry and as a common ingredient in various cosmetic products.

Plants of the Spontaneous Flora with Beneficial Action in the Management of Diabetes, Hepatic Disorders, and Cardiovascular Disease

The current pharmacological agents advised for the management of diabetes as well as cardiovascular and hepatic diseases are subject to numerous studies for safety and efficacy. Therefore, it is worth looking into alternative therapeutic aids such as natural products of medicinal plants. By a broad review of in vitro and in vivo studies on the various dandelion, chicory, and mulberry extracts, this work highlights their bioactive compounds and therapeutic action when used as a prevention and management aid in public health such as diabetes, cardiovascular disease, and hepatic disorders like non-alcoholic steatohepatitis. Natural products of dandelion leaves and root extracts can suppress the development of liver cancer, decrease insulin resistance, and suppress total triglyceride and cholesterol levels. Recent studies on mulberry leaves extracts indicated that they could decrease palmitic acid-induced lipotoxicity, increase total cholesterol and bile acid excretion, improve superoxide dismutase expression, and improve insulin resistance. Chicory root extracts boost satiety, reverse insulin resistance, and augment lipid metabolism thanks to their contents in chicoric acid, chlorogenic acid, and polysaccharides. Taraxacum officinale L., Morus nigra L., and Cichorium intybus L. present hepatoprotective, anti-inflammatory, antioxidant, hypolipidemic, and hypoglycemic activities and are shown to be advantageous in the management of obesity, dyslipidemia, Type 2 diabetes, and non-alcoholic fatty liver diseases. These plants are commonly available in the European spontaneous flora and more attention could be paid to their natural products.

Glucose transporters in the small intestine in health and disease

Absorption of monosaccharides is mainly mediated by Na+-D-glucose cotransporter SGLT1 and the facititative transporters GLUT2 and GLUT5. SGLT1 and GLUT2 are relevant for absorption of D-glucose and D-galactose while GLUT5 is relevant for D-fructose absorption. SGLT1 and GLUT5 are constantly localized in the brush border membrane (BBM) of enterocytes, whereas GLUT2 is localized in the basolateral membrane (BLM) or the BBM plus BLM at low and high luminal D-glucose concentrations, respectively. At high luminal D-glucose, the abundance SGLT1 in the BBM is increased. Hence, D-glucose absorption at low luminal glucose is mediated via SGLT1 in the BBM and GLUT2 in the BLM whereas high-capacity D-glucose absorption at high luminal glucose is mediated by SGLT1 plus GLUT2 in the BBM and GLUT2 in the BLM. The review describes functions and regulations of SGLT1, GLUT2, and GLUT5 in the small intestine including diurnal variations and carbohydrate-dependent regulations. Also, the roles of SGLT1 and GLUT2 for secretion of enterohormones are discussed. Furthermore, diseases are described that are caused by malfunctions of small intestinal monosaccharide transporters, such as glucose-galactose malabsorption, Fanconi syndrome, and fructose intolerance. Moreover, it is reported how diabetes, small intestinal inflammation, parental nutrition, bariatric surgery, and metformin treatment affect expression of monosaccharide transporters in the small intestine. Finally, food components that decrease D-glucose absorption and drugs in development that inhibit or downregulate SGLT1 in the small intestine are compiled. Models for regulations and combined functions of glucose transporters, and for interplay between D-fructose transport and metabolism, are discussed.

Does calorie restriction improve cognition?

Calorie restriction (CR) has been considered the most effective non-pharmacological intervention to counteract aging-related diseases and improve longevity. This intervention has shown beneficial effects in the prevention and treatment of several chronic diseases and functional declines related to aging, such as Parkinson's, Alzheimer's, and neuroendocrine disorders. However, the effects of CR on cognition show controversial results since its effects vary according to intensity, duration, and the period of CR. This review focuses on the main studies published in the last ten years regarding the consequences of CR on cognition in different neurological diseases and conditions of experimental animals. Also, possible CR mimetics are discussed. These findings highlight the potential beneficial effects of CR of up to 40 % on cognition when started early in life in non human animals.

Effects of Nigella sativa seed polysaccharides on type 2 diabetic mice and gut microbiota

Effect of Nigella sativa seed polysaccharides (NSSP) on type 2 diabetic mice and its gut microbiota was investigated on the type 2 diabetic mice model feed by high-fat diet. Fasting blood glucose (FBG), biochemical parameters, expression levels of cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and phosphor-AKT (p-AKT) protein, membrane glucose transporter 4 (GLUT4) in skeletal muscles, as well as the change of gut microbiota profile in mice model were measured. Results showed that the high-dose NSSP could significantly lower the levels of FBG, glycosylated serum protein (GSP), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), malondialdehyde (MDA), TNF-α, IL-6 and IL-1β, and significantly increased insulin (INS), high-density lipoprotein cholesterol (HDLC), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT) and the expression levels of p-AKT and GLUT4 in mice. Besides, the high-dose NSSP has significantly increased the abundance of f_Muribaculaceae_Unclassified and Bacteroides, which were significantly suppressed in the mice gut after the treatment of streptozotocin (STZ). These results indicated that NSSP could improve the abnormal state of diabetic mice by regulating the PI3K/AKT signaling pathway with simultaneous changes of the gut microbiota profile.

Enhancement of the Antioxidant, Anti-Tyrosinase, and Anti-Hyaluronidase Activity of Morus alba L. Leaf Extract by Pulsed Electric Field Extraction

In this study we aimed to compare the chemical composition and biological activity between Morus alba L. leaf extract obtained with 95% v/v ethanol using a pulsed electric field (PEF) and the conventional maceration method. Extracts of M. alba leaves collected from Chiang Mai (CM), Sakon Nakon (SK), and Buriram (BR), Thailand, were investigated for 1-deoxynojirimycin content by high-performance liquid chromatography and for total phenolic content by the Folin–Ciocalteu method. Antioxidant activity was investigated by 2,2′-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS), and ferric reducing antioxidant power (FRAP) assay. Anti-tyrosinase and anti-hyaluronidase activity was investigated by in vitro spectrophotometry. The results show that this is the first study to indicate PEF as a novel method for enhancing the phenolic content and antioxidant, anti-tyrosinase, and anti-hyaluronidase activity of M. alba leaf extract (P < 0.05). PEF extract of M. alba leaves collected from BR had comparable ABTS^•+ scavenging activity to l-ascorbic acid and comparable anti-tyrosinase activity to kojic acid (P > 0.05). On the other hand, PEF extract of M. alba leaves collected from SK exhibited significantly high anti-hyaluronidase activity, comparable to that of oleanolic acid (P > 0.05). Therefore, PEF is suggested for further M. alba leaf extraction in the production of natural whitening and anti-aging cosmetic ingredients.

The homogenous polysaccharide SY01-23 purified from leaf of Morus alba L. has bioactivity on human gut Bacteroides ovatus and Bacteroides cellulosilyticus

Function of mulberry leaf (Morus alba L.) polysaccharide has been reported on antitumor, immunostimulatory and anti-inflammatory effects. However, the bioactivity on human gut microbiota is unclear so far. Here, three homogenous polysaccharides named SY01-21, SY01-22, SY01-23 were isolated from mulberry leaf with molecular weight 57 kDa, 25 kDa and 7.2 kDa, respectively. The monosaccharide composition of SY01-21 contained rhamnose, galactose and arabinose in a molar ratio of 7.60:43.52:48.88. SY01-22 contained rhamnose, galacturonic acid, glucose, galactose, xylose and arabinose in a molar ratio of 14.61:9.06:1.35:34.65:2.99:37.34. SY01-23 contained rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose and arabinose in a molar ratio of 23.00:4.12:24.60:5.74:17.28:1.12:24.13. Bioactivity test showed SY01-21 promoted the growth of Bacteroides cellulosilyticus (BC) while SY01-22 benefited the growth of Bacteroides ovatus (BO). Interestingly, SY01-23 boosted the growth of both BO and BC. However, Bacteroides thetaiotamicron (BT) only grew on 5 mg/mL SY01-21. Intriguingly, the growth of co-culture of BT with BO or BC was better than monoculture. This suggested that cross-feeding might exist between them. Besides, we found BO and BC generated acetate and propionate by utilizing SY01-23. The above results suggested that SY01-23 might modify human gut microbiota by driving colonization of Bacteroides in the gut to improve wellness.

Administration of mulberry leaves maintains pancreatic β-cell mass in obese/type 2 diabetes mellitus mouse model

BACKGROUND

Type 2 diabetes mellitus is characterized by insulin resistance and pancreatic β-cell dysfunction. A decrease in β-cell mass, which occurs during the progression of Type 2 diabetes mellitus, contributes to impaired insulin secretion. Mulberry leaves contain various nutritional components that exert anti-diabetic and anti-atherogenic effects. The present study analyzed the effects of mulberry leaf intake on pancreatic β-cells to clarify the mechanisms underlying its anti-diabetic function.

METHODS

Mulberry leaves (Morus alba L.) were dried at 180 °C for 8 s in a hot-air mill and fed to obesity/Type 2 diabetes mellitus db/db mouse models at 5% (w/w) as part of a normal diet from 7 to 10, 15, or 20 weeks of age. An intraperitoneal glucose tolerance test was then performed on the mice. To evaluate the β-cell mass, the pancreas was subjected to immunohistological analysis with an anti-insulin antibody. A TUNEL assay and immunohistological analysis with a proliferation marker was also performed. Expression levels of endoplasmic reticulum stress-responsible genes and proliferation markers were assessed by quantitative RT-PCR.

RESULTS

Intake of mulberry leaves maintained the β-cell function of db/db mice. Moreover, oral administration of mulberry leaves significantly decreased cell death by reducing endoplasmic reticulum stress in the pancreas. Mulberry leaves significantly increased proliferation of β-cells and the expression of pancreatic duodenal homeobox1 mRNA in the pancreas.

CONCLUSION

Considered together, these results indicate that dietary mulberry leaf administration can maintain insulin levels and pancreatic β-cell mass, at least in part, by suppressing endoplasmic reticulum stress in Type 2 diabetes mellitus mouse models.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Isolation and hypoglycemic effects of water extracts from mulberry leaves in Northeast China

Diabetes is the main chronic disease that greatly affects human life.

Urinary Metabolomics Study of the Intervention Effect of Hypoglycemic Decoction on Type 2 Diabetes Mellitus Rats Model

The hypoglycemic decoction (HD) is a traditional Chinese medicine (TCM) preparation for the treatment of diabetes mellitus (DM), with a remarkable therapeutic effect. However, its mechanism of action is still unclear at the metabolic level. In this study, the biochemical markers from type 2 DM (T2DM) rats, induced by a high-sugar and high-fat diet combined with streptozotocin (STZ), were detected. The metabolomics-based analysis using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was conducted to evaluate urine samples from control, model, metformin, and HD groups. After oral administration of HD for 28 days, the general state, weight, fasting blood glucose (FBG), blood lipid level, oral glucose tolerance test (OGTT), fasting insulin (FINS), insulin sensitivity index (ISI), and homeostasis model assessment of insulin resistance (HOMA-IR) were significantly improved (P < 0.01). The western blotting showed that HD can enhance the protein expression of glucose transporter 4 (GLUT4) and adenosine monophosphate-activated protein kinase (AMPK). The metabolomics results revealed that after treatment with HD, the levels of L-carnitine, 1-methyladenosine, 1-methylhistamine, and 3-indoleacrylic acid were upregulated and the levels of riboflavin, phenylalanine, atrolactic acid, 2-oxoglutarate, citrate, isocitrate, cortisol, and glucose were downregulated. The main mechanism may be closely related to the regulation of the tricarboxylic acid (TCA) cycle, phenylalanine metabolism, glyoxylate metabolism, and dicarboxylate metabolism. Additionally, it was also found that HD can regulate the protein expression of GLUT4 and AMPK to interfere with TCA cycle and carbohydrate metabolism to treat T2DM.

The mechanism of mulberry leaves against renal tubular interstitial fibrosis through ERK1/2 signaling pathway was predicted by network pharmacology and validated in human tubular epithelial cells

Mulberry leaf was reported that it has antidiabetic activity, although the mechanisms underlying the function have not been fully elucidated. In the present study, the results of network pharmacology suggested that mulberry leaves could regulate key biological process in development of diabetes, and the process implicates multiple signaling pathways, such as JAK-STAT, MAPK, VEGF, PPAR, and Wnt. Then, the research in vitro indicated that mulberry leaves remarkably ameliorated high glucose-induced epithelial to mesenchymal transition, which was characterized with significant reduction of intracellular reactive oxygen species (ROS) levels as well as downregulation of NADPH oxidase subunits NOX1, NOX2, and NOX4, and it was found to be connected with the ERK1/2 signaling pathway in human tubular epithelial cells (HK-2). Moreover, the results of bioinformatics and the dual luciferase report showed that ZEB1 might be a target gene of miR-302a; decreased miR-302a and increased ZEB1 expressions could significantly promote epithelial to mesenchymal transition. However, mulberry leaves could reverse these modulations. Our results demonstrated that network pharmacology could provide a guidance role for traditional Chinese medicine research, and mulberry leaves could be of benefit in preventing high glucose-induced EMT in HK-2 cells, which proved that it was related to the upregulation of miR-302a by targeting ZEB1 and the inhibition of NADPH oxidase/ROS/ERK1/2 pathway.

Purification, characterization and in vitro and in vivo immune enhancement of polysaccharides from mulberry leaves

Mulberry leaf polysaccharide (MLP) was extracted and purified by DEAE-52 cellulose and Sephadex G-100 column chromatography to afford two major purified polysaccharides (MLP-1 and MLP-2). The purified polysaccharides were characterized, and their immune-enhancing properties were investigated. MLP-1 had a molecular weight of 9.31×104 Da and was composed of mannose, rhamnose, glucose, galactose, xylose, and arabinose in a molar ratio of 0.71:1.00:2.76:1.13:3.70:2.81. The molecular weight of MLP-2 was 2.22×106 Da, and its monosaccharide constituents were mannose, rhamnose, glucose, galactose, and arabinose in a molar ratio of 1.31:8.45:6.94:1.00:11.96. Infrared spectroscopy showed that each MLP had a typical absorption peak characteristic of sugars, and ultraviolet (UV) spectroscopy showed that neither MLP contained nucleic acid or protein components. Then, the abilities of these polysaccharides to stimulate spleen lymphocyte proliferation in mice in vitro were compared by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. MLP-2 was more effective than MLP-1; therefore, MLP-2 was chosen for the study of its immune-enhancing effects in vivo. For the in vivo experiments, 14-day-old chickens immunized with Newcastle disease (ND) vaccine were orally administered MLP-2, and Astragalus polysaccharide (APS) was used as the control. Each chicken was orally administered 4 mg or 8 mg of MLP-2 for seven consecutive days starting three days before ND vaccine immunization. MLP-2 significantly improved the ND serum antibody titer and interleukin-2 (IL-2), interferon-γ (IFN-γ) and immunoglobulin A (sIgA) concentrations in tracheal and jejunal wash fluids, and increasing numbers of immune globulin A-positive (IgA+) cells in cecal tonsils and increased body weight. These results indicated that MLP-2 could significantly enhance immune activity and could therefore be utilized as an immunopotentiator drug candidate.

A Systematic Review of the Medicinal Potential of Mulberry in Treating Diabetes Mellitus

Diabetes mellitus (DM) is a serious metabolic disorder which has reached epidemic proportions all over the world. Despite tremendous developments in medicinal chemistry, traditional medicine is still commonly used for the prevention and treatment of DM. Traditional herbal medicines have played a major role in the management of DM in Asian countries. In particular, mulberry has commonly been utilized in China for the treatment of DM for thousands of years. In the last decade, numerous preclinical findings have suggested that mulberry is a promising therapeutic agent for the treatment of DM, and the polyhydroxylated alkaloids, flavonoids and polysaccharides from mulberry may be the potential active components. The present review systematically summarizes the chemical composition of mulberry and the pharmacological effects of different medicinal parts on DM; these effects include influences on glucose absorption, insulin (INS) production/secretion, anti-oxidation and anti-inflammation processes. After summarizing our research findings, we will discuss the challenges and opportunities and explore the direction of future research and the potential for developing mulberry into pharmaceuticals for the widespread treatment of DM.

Coating rice with mulberry leaves rich in deoxynojirimycin ameliorates hyperglycemia and dyslipidemia in C57BL/KsJ db/db mice

BACKGROUND/OBJECTIVES

Mulberry leaf (ML) has been shown to have an inhibitory effect on α-glucosidase, and suppresses postprandial hyperglycemia, which may be related to its deoxynojirimycin (DNJ) content. This study was conducted to investigate the hypoglycemic and dyslipidemic effects of rice coated with ML rich in DNJ in a type 2 diabetes mouse model.

MATERIALS/METHODS

The mice were divided into four groups (n = 8 each): non-diabetic normal control (NC); diabetic control (DM-C), fed with 10% polished rice powder (DM-R); and fed with 10% polished rice powder coated with DNJ-rich ML (DM-DNJR).

RESULTS

Supplementation with DNJR for six weeks decreased levels of fasting blood glucose, plasma insulin, triglyceride, total cholesterol, and blood glycosylated hemoglobin; conversely, levels of glucagon-like peptide-1 and high-density lipoprotein-cholesterol showed an increase in the same treatment. In addition, weights of mesenteric, epididymal, and total adipose tissues decreased with DNJR supplementation, when compared with diabetic control db/db mice, while maltase, lactase, and sucrase activity in the small intestine were inhibited. The anti-diabetic effects were marginally greater in the DM-DNJR group than in the DM-R group.

CONCLUSIONS

These results suggest that rice coated with ML rich in DNJ can reduce hyperglycemia and hyperlipidemia in db/db mice, and may prove useful for individuals with diabetes.

Transcriptome analysis and identification of key genes involved in 1-deoxynojirimycin biosynthesis of mulberry (Morus alba L.)

Mulberry (Morus alba L.) represents one of the most commonly utilized plants in traditional medicine and as a nutritional plant used worldwide. The polyhydroxylated alkaloid 1-deoxynojirimycin (DNJ) is the major bioactive compounds of mulberry in treating diabetes. However, the DNJ content in mulberry is very low. Therefore, identification of key genes involved in DNJ alkaloid biosynthesis will provide a basis for the further analysis of its biosynthetic pathway and ultimately for the realization of synthetic biological production. Here, two cDNA libraries of mulberry leaf samples with different DNJ contents were constructed. Approximately 16 Gb raw RNA-Seq data was generated and de novo assembled into 112,481 transcripts, with an average length of 766 bp and an N50 value of 1,392. Subsequently, all unigenes were annotated based on nine public databases; 11,318 transcripts were found to be significantly differentially regulated. A total of 38 unique candidate genes were identified as being involved in DNJ alkaloid biosynthesis in mulberry, and nine unique genes had significantly different expression. Three key transcripts of DNJ biosynthesis were identified and further characterized using RT-PCR; they were assigned to lysine decarboxylase and primary-amine oxidase genes. Five CYP450 transcripts and two methyltransferase transcripts were significantly associated with DNJ content. Overall, the biosynthetic pathway of DNJ alkaloid was preliminarily speculated.

Mulberry Leaf Regulates Differentially Expressed Genes in Diabetic Mice Liver Based on RNA-Seq Analysis

The pathogenesis of diabetes mellitus is a complicated process involving much gene regulation. The molecular mechanism of mulberry (Morus alba L.) leaf in the treatment of diabetes is not fully understood. In this study, we used the Illumina HiSeq™ 2,500 platform to explore the liver transcriptome of normal mice, STZ-induced diabetic mice, and mulberry leaf-treated diabetic mice, and we obtained 52,542,956, 52,626,414, and 52,780,196 clean reads, respectively. We identified differentially expressed genes (DEGs) during the pathogenesis of diabetes in mice. The functional properties of DEGs were characterized by comparison with the GO and KEGG databases, and the results show that DEGs are mainly involved in the metabolic pathway. qRT-PCR was used to analyse 27 differential genes involved in liver expression in different groups of diabetic mice. Among the DEGs, the expression of Scube1, Spns3, Ly6a, Igf2, and other genes between the control (C) and diabetic control (DC) groups was significantly upregulated; the expression of Grb10, Mup2, and Fasn was significantly downregulated; the expression of the Sqle, Lss, and Irs2 genes between the C group and diabetic group treated with mulberry (DD) was significantly upregulated; the expression of Fabp2, Ly6a, and Grb10 was significantly downregulated; and the expression of Sqle and Lss was significantly upregulated in the DC and DD groups, but Tap1, Igf2, and Spns3 were significantly downregulated. The results of Western blot validation showed that dynamic changes in proteins, such as IGF2, Ly6a, Grb10, and UBD, occurred to regulate the incidence of diabetes by influencing the insulin receptor substrate (IRS) signaling pathway.

Mulberry Leaf Regulates Differentially Expressed Genes in Diabetic Mice Liver Based on RNA-Seq Analysis

The pathogenesis of diabetes mellitus is a complicated process involving much gene regulation. The molecular mechanism of mulberry (Morus alba L.) leaf in the treatment of diabetes is not fully understood. In this study, we used the Illumina HiSeq™ 2,500 platform to explore the liver transcriptome of normal mice, STZ-induced diabetic mice, and mulberry leaf-treated diabetic mice, and we obtained 52,542,956, 52,626,414, and 52,780,196 clean reads, respectively. We identified differentially expressed genes (DEGs) during the pathogenesis of diabetes in mice. The functional properties of DEGs were characterized by comparison with the GO and KEGG databases, and the results show that DEGs are mainly involved in the metabolic pathway. qRT-PCR was used to analyse 27 differential genes involved in liver expression in different groups of diabetic mice. Among the DEGs, the expression of Scube1, Spns3, Ly6a, Igf2, and other genes between the control (C) and diabetic control (DC) groups was significantly upregulated; the expression of Grb10, Mup2, and Fasn was significantly downregulated; the expression of the Sqle, Lss, and Irs2 genes between the C group and diabetic group treated with mulberry (DD) was significantly upregulated; the expression of Fabp2, Ly6a, and Grb10 was significantly downregulated; and the expression of Sqle and Lss was significantly upregulated in the DC and DD groups, but Tap1, Igf2, and Spns3 were significantly downregulated. The results of Western blot validation showed that dynamic changes in proteins, such as IGF2, Ly6a, Grb10, and UBD, occurred to regulate the incidence of diabetes by influencing the insulin receptor substrate (IRS) signaling pathway.