Ethanol extract of mulberry leaves partially restores the composition of intestinal microbiota and strengthens liver glycogen fragility in type 2 diabetic rats

Positive effects and mechanism of mulberry leaf extract on alleviating fatty liver hemorrhagic syndrome in laying hens

This experiment was conducted to investigate the effects of mulberry leaf extract (MLE) on alleviating fatty liver hemorrhagic syndrome (FLHS) in laying hens. The 576 Jing Fen laying hens of 56 weeks of age with good health and similar weights (1.76 ± 0.17 kg) were randomly divided into 6 groups, with 8 replicates in each group and 12 chickens in each replicate. The experiment lasted 56 d. The control group was fed a corn-soybean meal diet. The FLHS group was fed a high energy-low protein (HELP) diet, and the other four experimental groups were fed HELP diets supplemented with 0.04, 0.40, 0.80, and 1.20% MLE, respectively. The results showed that HELP treatment significantly induced liver injury, which indicated that the FLHS model was successfully established. MLE supplementation could alleviate the FLHS by reducing the liver index, abdominal fat percentage, total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) in the serum (P < 0.05), and subsequently increase the egg production rate (P < 0.05). The laying hens fed 0.8% MLE exhibited the greatest production performance (P < 0.05) and could improve serum lipid levels. In addition, the genes associated with fatty acid synthesis (ACC, HMGR and SREBP-1C) were downregulated (P < 0.05), and genes related to fatty acid oxidation (CPT1A, AMPK, and ATGL) were found to be upregulated (P < 0.05). Supplementation with 1.2% MLE significantly reduced the relative abundance of Firmicutes and Desulfurized Bacillus (P < 0.05) and significantly increased the relative abundance of Fecal Bacillus (P < 0.05). In conclusion, MLE may regulate the mRNA expression of lipid metabolism-related genes through the AMPK signaling pathway and improve cecal microbiota balance and serum lipid levels to alleviate FLHS in laying hens and subsequently improve egg production performance.

From ancient wisdom to modern science: Gut microbiota sheds light on property theory of traditional Chinese medicine

The property theory of traditional Chinese medicine (TCM) has been practiced for thousands of years, playing a pivotal role in the clinical application of TCM. While advancements in energy metabolism, chemical composition analysis, machine learning, ion current modeling, and supercritical fluid technology have provided valuable insight into how aspects of TCM property theory may be measured, these studies only capture specific aspects of TCM property theory in isolation, overlooking the holistic perspective inherent in TCM. To systematically investigate the modern interpretation of the TCM property theory from multidimensional perspectives, we consulted the Chinese Pharmacopoeia (2020 edition) to compile a list of Chinese materia medica (CMM). Then, using the Latin names of each CMM and gut microbiota as keywords, we searched the PubMed database for relevant research on gut microbiota and CMM. The regulatory patterns of different herbs on gut microbiota were then summarized from the perspectives of the four natures, the five flavors and the meridian tropism. In terms of the four natures, we found that warm-natured medicines promoted the colonization of specific beneficial bacteria, while cold-natured medicines boosted populations of some beneficial bacteria while suppressing pathogenic bacteria. Analysis of the five flavors revealed that sweet-flavored and bitter-flavored CMMs positively influenced beneficial bacteria while inhibiting harmful bacteria. CMMs with different meridian tropism exhibited complex modulative patterns on gut microbiota, with Jueyin (Liver) and Taiyin (Lung) meridian CMMs generally exerting a stronger effect. The gut microbiota may be a biological indicator for characterizing the TCM property theory, which not only enhances our understanding of classic TCM theory but also contributes to its scientific advancement and application in healthcare. Please cite this article as: Yang YN, Zhan JG, Cao Y, Wu CM. From ancient wisdom to modern science: Gut microbiota sheds light on property theory of traditional Chinese medicine. J Integr Med 2024; 22(4): 413-445.

gys1 regulates maternal glycogen reserve essential for embryonic development in zebrafish

The reserve of glycogen is essential for embryonic development. In oviparous fish, egg is an isolated system after egg laying with all the required energy deposits by their mothers. However, the key regulated factor mediates the storage of maternal glycogen reserve which support for embryogenesis in the offspring is largely unknown. Glycogen synthase (GYS) is a central enzyme for glycogen synthesis. In our previous study, we generated a gys1 knockout zebrafish line, showed an embryonic developmental defect in F3 generation. In this study, firstly we determined that the gys1 was maternal origin by backcrossing the F2 mutant with wildtype lines. PAS staining and glycogen content measurement showed that glycogen reserve was reduced both in ovaries and embryos in the mutant group compared to wildtypes. Free glucose measurement analysis showed a 50 % of reduction in gys1 mutant embryos compared to wildtype embryos at 24 hpf; showed an approximal 50 % of reduction in gys1 mutant adults compared to wildtypes. Microinjection of 2-NBDG in embryos and comparison of fluorescent signal demonstrated that glucose uptake ability was decreased in the mutant embryos, indicating an impaired glucose metabolism. Untargeted metabolomics analysis then was employed and revealed that key modified metabolites enriched into vitamin B pathway, carbohydrate and unsaturated fatty acid pathways. These results demonstrated that gys1 played a role on glycogen metabolism, involved into the maternal glycogen reserve which essentially contribute to embryonic development.

Potential Role and Mechanism of Mulberry Extract in Immune Modulation: Focus on Chemical Compositions, Mechanistic Insights, and Extraction Techniques

Mulberry is a rapidly growing plant that thrives in diverse climatic, topographical, and soil types, spanning temperature and temperate countries. Mulberry plants are valued as functional foods for their abundant chemical composition, serving as a significant reservoir of bioactive compounds like proteins, polysaccharides, phenolics, and flavonoids. Moreover, these compounds displayed potent antioxidant activity by scavenging free radicals, inhibiting reactive oxygen species generation, and restoring elevated nitric oxide production induced by LPS stimulation through the downregulation of inducible NO synthase expression. Active components like oxyresveratrol found in Morus demonstrated anti-inflammatory effects by inhibiting leukocyte migration through the MEK/ERK signaling pathway. Gallic and chlorogenic acids in mulberry leaves (ML) powder-modulated TNF, IL-6, and IRS1 proteins, improving various inflammatory conditions by immune system modulation. As we delve deeper into understanding its anti-inflammatory potential and how it works therapeutically, it is crucial to refine the extraction process to enhance the effectiveness of its bioactive elements. Recent advancements in extraction techniques, such as solid-liquid extraction, pressurized liquid extraction, superficial fluid extraction, microwave-assisted extraction, and ultrasonic-assisted extraction, are being explored. Among the extraction methods tested, including Soxhlet extraction, maceration, and ultrasound-assisted extraction (UAE), UAE demonstrated superior efficiency in extracting bioactive compounds from mulberry leaves. Overall, this comprehensive review sheds light on the potential of mulberry as a natural immunomodulatory agent and provides insights into its mechanisms of action for future research and therapeutic applications.

Structure-function relationship and biological activity of polysaccharides from mulberry leaves: A review

Mulberry (Latin name "Morus alba L.") is a perennial deciduous tree in the family of Moraceae, widely distributed around the world. In China, mulberry is mainly distributed in the south and the Yangtze River basin. Its leaves can be harvested 3-6 times a year, which has a great resource advantage. Mulberry leaves are regarded as the homology of medicine and food traditional Chinese medicine (TCM). Polysaccharides, as its main active ingredients, have various effects, such as antioxidant, hypoglycemic, hepatoprotective, and immunomodulatory. This review summarizes the research progress in the extraction, purification, structural characterization, and structure-function relationship of polysaccharides from mulberry leaves in the last decade, hoping to provide a reference for the subsequent development and market application of polysaccharides from mulberry leaves.

Mulberry Leaf Dietary Supplementation Can Improve the Lipo-Nutritional Quality of Pork and Regulate Gut Microbiota in Pigs: A Comprehensive Multi-Omics Analysis

Mulberry leaves, a common traditional Chinese medicine, represent a potential nutritional strategy to improve the fat profile, also known as the lipo-nutrition, of pork. However, the effects of mulberry leaves on pork lipo-nutrition and the microorganisms and metabolites in the porcine gut remain unclear. In this study, multi-omics analysis was employed in a Yuxi black pig animal model to explore the possible regulatory mechanism of mulberry leaves on pork quality. Sixty Yuxi black pigs were divided into two groups: the control group (n = 15) was fed a standard diet, and the experimental group (n = 45) was fed a diet supplemented with 8% mulberry leaves. Experiments were performed in three replicates (n = 15 per replicate); the two diets were ensured to be nutritionally balanced, and the feeding period was 120 days. The results showed that pigs receiving the diet supplemented with mulberry leaves had significantly reduced backfat thickness (p < 0.05) and increased intramuscular fat (IMF) content (p < 0.05) compared with pigs receiving the standard diet. Lipidomics analysis showed that mulberry leaves improved the lipid profile composition and increased the proportion of triglycerides (TGs). Interestingly, the IMF content was positively correlated with acyl C18:2 and negatively correlated with C18:1 of differential TGs. In addition, the cecal microbiological analysis showed that mulberry leaves could increase the abundance of bacteria such as UCG-005, Muribaculaceae_norank, Prevotellaceae_NK3B31_group, and Limosilactobacillus. Simultaneously, the relative levels of L-tyrosine-ethyl ester, oleic acid methyl ester, 21-deoxycortisol, N-acetyldihydrosphingosine, and mulberrin were increased. Furthermore, we found that mulberry leaf supplementation significantly increased the mRNA expression of lipoprotein lipase, fatty acid-binding protein 4, and peroxisome proliferators-activated receptor γ in muscle (p < 0.01). Mulberry leaf supplementation significantly increased the mRNA expression of diacylglycerol acyltransferase 1 (p < 0.05) while significantly decreasing the expression of acetyl CoA carboxylase in backfat (p < 0.05). Furthermore, mulberry leaf supplementation significantly upregulated the mRNA expression of hormone-sensitive triglyceride lipase and peroxisome proliferator-activated receptor α (p < 0.05) in backfat. In addition, mulberry leaf supplementation led to increased serum leptin and adiponectin (p < 0.01). Collectively, this omic profile is consistent with an increased ratio of IMF to backfat in the pig model.

Role of the gut microbiota in the pathogenesis of endometriosis: a review

Endometriosis is classically defined as a chronic inflammatory heterogeneous disorder occurring in any part of the body, characterized by estrogen-driven periodic bleeding, proliferation, and fibrosis of ectopic endometrial glands and stroma outside the uterus. Endometriosis can take overwhelmingly serious damage to the structure and function of multi-organ, even impair whole-body systems, resulting in severe dysmenorrhea, chronic pelvic pain, infertility, fatigue and depression in 5-10% women of reproductive age. Precisely because of a huge deficiency of cognition about underlying etiology and complex pathogenesis of the debilitating disease, early diagnosis and treatment modalities with relatively minor side effects become bottlenecks in endometriosis. Thus, endometriosis warrants deeper exploration and expanded investigation in pathogenesis. The gut microbiota plays a significant role in chronic diseases in humans by acting as an important participant and regulator in the metabolism and immunity of the body. Increasingly, studies have shown that the gut microbiota is closely related to inflammation, estrogen metabolism, and immunity resulting in the development and progression of endometriosis. In this review, we discuss the diverse mechanisms of endometriosis closely related to the gut microbiota in order to provide new approaches for deeper exploration and expanded investigation for endometriosis on prevention, early diagnosis and treatment.

Dietary Morus alba L. leaf supplementation improves hepatic lipid accumulation of laying hens via downregulating CircACACA

Fatty liver hemorrhagic syndrome (FLHS) is the most common metabolic disease in laying hens. Morus alba L. (mulberry) leaf has the effect of regulating lipid metabolism. We evaluated the effects of dietary 3% mulberry leaf (MUL) supplementation in production performance, egg quality, and liver lipid deposition in laying hens. Differentially expressed genes and circRNAs in the liver were identified using whole-transcriptome sequencing. We also evaluated the effects of the MUL extract using an in vitro model of primary hepatocytes induced by free fatty acids and explored the role of key circRNAs in this process. Dietary supplementation with 3% MUL alleviated liver steatosis in laying hens, as shown by decreased fatty liver color score, relative liver weight (P < 0.01), and triglyceride levels (P < 0.05), and showed a tendency to reduce the mortality rate of laying hens (P = 0.09). In addition, mulberry leaf supplementation significantly reduced cholesterol content in egg yolk (P < 0.01). Dietary mulberry leaf supplementation downregulated the expression of genes involved in fatty acid and cholesterol biosynthesis, and upregulated the expression of fatty acid oxidation-related genes in the liver. CircACACA, which is derived from exons 2 and 3 of the acetyl-CoA carboxylase alpha (ACACA) pre-mRNA, was significantly reduced in the MUL group (P < 0.01). Upregulation of circACACA expression reversed the lipid-lowering effect of mulberry leaf extract by upregulating sterol regulatory element-binding proteins 1 c (SREBP-1c) and fatty acid synthase (FASN) (P < 0.05). Overall, mulberry leaf is an effective therapeutic strategy for FLHS in hens and can improve liver lipid metabolism by downregulating circACACA.

A Basic Study of the Effects of Mulberry Leaf Administration to Healthy C57BL/6 Mice on Gut Microbiota and Metabolites

Mulberry leaves contain α-glucosidase inhibitors, which have hypoglycemic effects and are considered functional foods. However, few reports have covered the effects of mulberry leaf components on normal gut microbiota and gut metabolites. Herein, gut microbiota analysis and NMR-based metabolomics were performed on the feces of mulberry leaf powder (MLP)-treated mice to determine the effects of long-term MLP consumption. Gut microbiota in the mouse were analyzed using 16S-rRNA gene sequencing, and no significant differences were revealed in the diversity and community structure of the gut microbiota in the C57BL/6 mice with or without MLP supplementation. Thirty-nine metabolites were identified via 1H-NMR analysis, and carbohydrates and amino acids were significantly (p < 0.01-0.05) altered upon MLP treatment. In the MLP-treated group, there was a marked increase and decrease in maltose and glucose concentrations, respectively, possibly due to the degradation inhibitory activity of oligosaccharides. After 5 weeks, all amino acid concentrations decreased. Furthermore, despite clear fluctuations in fecal saccharide concentrations, short-chain fatty acid production via intestinal bacterial metabolism was not strongly affected. This study provides the knowledge that MLP administration can alter the gut metabolites without affecting the normal gut microbiota, which is useful for considering MLP as a healthy food source.

Identifying potential therapeutic targets of mulberry leaf extract for the treatment of type 2 diabetes: a TMT-based quantitative proteomic analysis

BACKGROUND

Mulberry (Morus alba L.) leaf, as a medicinal and food homologous traditional Chinese medicine, has a clear therapeutic effect on type 2 diabetes mellitus (T2DM), yet its underlying mechanisms have not been totally clarified. The study aimed to explore the mechanism of mulberry leaf in the treatment of T2DM through tandem mass tag (TMT)-based quantitative proteomics analysis of skeletal muscle.

METHODS

The anti-diabetic activity of mulberry leaf extract (MLE) was evaluated by using streptozotocin-induced diabetic rats at a dose of 4.0 g crude drug /kg p.o. daily for 8 weeks. Fasting blood glucose, body weight, food and water intake were monitored at specific intervals, and oral glucose tolerance test and insulin tolerance test were conducted at the 7th and 8th week respectively. At the end of the experiment, levels of glycated hemoglobin A1c, insulin, free fat acid, leptin, adiponectin, total cholesterol, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were assessed and the pathological changes of rat skeletal muscle were observed by HE staining. TMT-based quantitative proteomic analysis of skeletal muscle and bioinformatics analysis were performed and differentially expressed proteins (DEPs) were validated by western blot. The interactions between the components of MLE and DEPs were further assessed using molecular docking.

RESULTS

After 8 weeks of MLE intervention, the clinical indications of T2DM such as body weight, food and water intake of rats were improved to a certain extent, while insulin sensitivity was increased and glycemic control was improved. Serum lipid profiles were significantly reduced, and the skeletal muscle fiber gap and atrophy were alleviated. Proteomic analysis of skeletal muscle showed that MLE treatment reversed 19 DEPs in T2DM rats, regulated cholesterol metabolism, fat digestion and absorption, vitamin digestion and absorption and ferroptosis signaling pathways. Key differential proteins Apolipoprotein A-1 (ApoA1) and ApoA4 were successfully validated by western blot and exhibited strong binding activity to the MLE's ingredients.

CONCLUSIONS

This study first provided skeletal muscle proteomic changes in T2DM rats before and after MLE treatment, which may help us understand the molecular mechanisms, and provide a foundation for developing potential therapeutic targets of anti-T2DM of MLE.

The linkage of gut microbiota and the property theory of traditional Chinese medicine (TCM): Cold-natured and sweet-flavored TCMs as an example

ETHNOPHARMACOLOGICAL RELEVANCE

The property theory of traditional Chinese medicine (TCM) is a unique medical theory based on an extensive clinical practice for thousands of years, which guides TCM doctors choosing proper medicines to treat specific diseases. The nature and flavor of TCM are a high generalization of drug's characteristics according to the property theory. Despite intensive investigations, the modern interpretation of TCM property theory still confronts several challenges, which greatly hampers the elucidation of TCM's mechanisms as well as its application. Compelling evidence has proved that gut microbiota may be a potential indicator for TCM's efficacy and mechanism. Nevertheless, at present, the relationship between the gut microbiota and the nature and flavor of TCM has not been fully elucidated.

AIM OF THE STUDY

To fill the gap in this field, we developed a comprehensive study to investigate the relationship between gut microbial community and TCM's property.

MATERIALS AND METHODS

We searched "PubMed" and "China National Knowledge Infrastructure (CNKI)" with the key word "gut microbiota", and screened the published articles related to TCM. In this review, we mainly applied cold-natured and sweet-flavored TCMs as an example to explore the modulation of cold-natured and sweet-flavored TCMs on gut microbiota, and identify the potential relationship between the alterations of gut microbiota and TCM's efficacy.

RESULTS

We found cold-natured and sweet-flavored TCMs possess several pharmacological activities and generally enrich beneficial bacteria like Akkermansia, Bacteroides, Lactobacillus and Bifidobacterium, which is in good accordance with their pharmacological effects. Simultaneously, these TCMs reduce the relative abundance of some harmful bacteria belonging to Firmicutes (Streptpcoccus, Enterococcus, Turicibacter, Anaerostipes and Oscillibacter) and Proteobacteria (Helicobacter, Enterobacter, Sutterella, Klebsiella, Desulfovibrio, Escherichia coli and Campylobacter jejuni). These results indicate that there are some intrinsic correlations between gut microbiota and the property of TCM, and gut microbiota may serve as a potential indicator to reflect the property of TCM.

CONCLUSIONS

This pilot but comprehensive review provides an interesting proposal that the ancient theory of TCM property may be interpreted by the modern biological findings in gut microbiome.

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.

Evaluation of mulberry leaves’ hypoglycemic properties and hypoglycemic mechanisms

The effectiveness of herbal medicine in treating diabetes has grown in recent years, but the precise mechanism by which it does so is still unclear to both medical professionals and diabetics. In traditional Chinese medicine, mulberry leaf is used to treat inflammation, colds, and antiviral illnesses. Mulberry leaves are one of the herbs with many medicinal applications, and as mulberry leaf study grows, there is mounting evidence that these leaves also have potent anti-diabetic properties. The direct role of mulberry leaf as a natural remedy in the treatment of diabetes has been proven in several studies and clinical trials. However, because mulberry leaf is a more potent remedy for diabetes, a deeper understanding of how it works is required. The bioactive compounds flavonoids, alkaloids, polysaccharides, polyphenols, volatile oils, sterols, amino acids, and a variety of inorganic trace elements and vitamins, among others, have been found to be abundant in mulberry leaves. Among these compounds, flavonoids, alkaloids, polysaccharides, and polyphenols have a stronger link to diabetes. Of course, trace minerals and vitamins also contribute to blood sugar regulation. Inhibiting alpha glucosidase activity in the intestine, regulating lipid metabolism in the body, protecting pancreatic -cells, lowering insulin resistance, accelerating glucose uptake by target tissues, and improving oxidative stress levels in the body are some of the main therapeutic properties mentioned above. These mechanisms can effectively regulate blood glucose levels. The therapeutic effects of the bioactive compounds found in mulberry leaves on diabetes mellitus and their associated molecular mechanisms are the main topics of this paper’s overview of the state of the art in mulberry leaf research for the treatment of diabetes mellitus.

The gut microbiota pathway mechanisms of diabetes

The contribution of dysbiotic gut microbiota configuration is essential when making reference to the metabolic disorders by increasing energy. It is important to understand that the gut microbiota induced metabolic disease mechanisms and inflammations. Thus it is imperative to have an insight into the state of all chronic subclinical inflammations influencing disease outcomes. However, from the emerging studies, there still exist inconsistencies in the findings of such studies. While making the best out of the reasons for inconsistencies of the findings, this review is designed to make a clear spell out as to the inconsistence of gut microbiota with respect to diabetes. It considered gut-virome alterations and diabetes and gut-bacteriome-gut-virome-alterations and diabetes as confounding factors. The review further explained some study design strategies that will spontaneously eliminate any potential confounding factors to lead to a more evidence based diabetic-gut microbiota medicine. Lipopolysaccharide (LPS) pro-inflammatory, metabolic endotoxemia and diet/gut microbiota insulin-resistance and low-grade systemic inflammation induced by gut microbiota can trigger pro-inflammatory cytokines in insulin-resistance, consequently, leading to the diabetic condition. While diet influences the gut microbiota, the consequences are mainly the constant high levels of pro-inflammatory cytokines in the circulatory system. Of recent, dietary natural products have been shown to be anti-diabetic. The effects of resveratrol on the gut showed an improved lipid profile, anti-inflammatory properties and ameliorated the endotoxemia, tight junction and glucose intolerance.

Mulberry (Morus alba L.) Leaf Extract and 1-Deoxynojirimycin Improve Skeletal Muscle Insulin Resistance via the Activation of IRS-1/PI3K/Akt Pathway in db/db Mice

Mulberry (Morus alba L.) leaves have been used to lower blood glucose in patients with diabetes. We evaluated the effects of mulberry leaves extract (MLE) and 1-deoxynojirimycin (1-DNJ) in improving insulin resistance through the activation of the IRS-1/PI3K/Akt pathway in the skeletal muscle of db/db mice. Histological analysis revealed an amelioration of muscle deformation and increased muscle fiber size. MLE and 1-DNJ positively raised the protein expression of related glucose uptake and increased the translocation of glucose transporter type 4 (GLUT4) to the membrane. Furthermore, MLE and 1-DNJ activated the IRS-1/PI3K/Akt pathway in the skeletal muscle and, subsequently, modulated the protein levels of glycogen synthase kinase-3beta (GSK-3β) and glycogen synthase (GS), leading to elevated muscle glycogen content. These findings suggest that MLE and 1-DNJ supplementation improves insulin resistance by modulating the insulin signaling pathway in the skeletal muscle of db/db mice.

Lipid metabolism disorders and lipid mediator changes of mice in response to long-term exposure to high-fat and high sucrose diets and ameliorative effects of mulberry leaves

Mulberry leaves exhibit anti-lipogenic and lipid-lowering effects. However, the lipid biomarkers and underlying mechanisms for the improvement of the action of mulberry leaves on obesity and lipid metabolism disorders have not been sufficiently investigated yet. Herein, biochemical analysis combined with metabolomics targeting serum lipid mediators (oxylipins) were used to explore the efficacy and underlying mechanisms of mulberry leaf water extract (MLWE) in high-fat and high-sucrose diet (HFHSD)-fed mice. Our results showed that MLWE supplementation not only decreased body weight gain, serum total triglycerides, low-density lipoprotein cholesterol, alanine transaminase and aspartate transaminase levels, but also increased the serum level of high-density lipoprotein cholesterol. In addition, MLWE supplementation also ameliorated hepatic steatosis and lipid accumulation. These beneficial effects were associated with down-regulating genes involved in oxidative stress, inflammation, and lipogenesis such as acetyl-CoA carboxylase and fatty acid synthase, and up-regulating genes related to lipolysis that encoded peroxisome proliferator-activated receptor α, adiponectin (ADPN), adiponectin receptor (AdipoR) 1, AdipoR2, adenosine monophosphate-activated protein kinase (AMPK) and hormone-sensitive lipase. Moreover, a total of 54 serum lipid mediators were differentially changed in HFHSD-fed mice, among which 11 lipid mediators from n-3 polyunsaturated fatty acids (PUFAs) were apparently reversed by MLWE. These findings indicated that the ADPN/AMPK pathway, anti-inflammation, anti-oxidation, and n-3 PUFA metabolism played important roles in anti-obesity and improvement of lipid metabolism disorders modulated by MLWE supplementation.

Anti-Inflammatory and Anti-Bacterial Potential of Mulberry Leaf Extract on Oral Microorganisms

Mulberry leaves extract (Morus alba extracts; MAE) is known to have therapeutic potentials for numerous human diseases, including diabetes, neurological disorders, cardiovascular diseases, and cancers. However, there has not been sufficient research proving therapeutic effects on oral disease and its related oral risk factors. Thus, we investigated whether MAE has any anti-inflammatory and anti-bacterial effects on risk factors causing oral infectious diseases. To examine the anti-inflammatory response and bacterial inhibition of MAE, we measured intracellular reactive oxygen species (ROS) generation, production of pro-inflammatory cytokines, and the bacterial growth rate. Our study showed that MAE has anti-inflammatory activities, which inhibit the ROS generation and suppressed the production of pro-inflammatory cytokines (TNF-α and IL-6) in human monocyte THP-1 cells by stimulating lipopolysaccharide (LPS) and/or F. nucleatum, which are the virulent factors in periodontal diseases. Furthermore, MAE inhibited the bacterial growth on oral microorganisms (F. nucleatum and S. mutans) infected THP-1 cells. These findings suggested that MAE could be a potential natural source for therapeutic drugs in oral infectious disease.