Berberine Modulates Gut Microbiota and Reduces Insulin Resistance via the TLR4 Signaling Pathway

An insight into the medicinal attributes of berberine derivatives: A review

In the last few decades, traditional natural products have been the center of attention for the scientific community and exploration of their therapeutic abilities is proceeding perpetually. Berberine, with remarkable therapeutic diversity, is a plant derived isoquinoline alkaloid which is widely used as a traditional medicine in China. Berberine has been tackled as a fascinating pharmacophore to make great contributions to the discovery and development of new therapeutic agents against variegated diseases. Despite its tremendous therapeutic potential, clinical utility of this alkaloid was significantly compromised due to undesirable pharmacokinetic properties. To overcome this limitation, several structural modifications were performed on this scaffold to improve its therapeutic efficacy. The collective efforts of the community have achieved the tremendous advancements, bringing berberine to clinical use and discovering new therapeutic opportunities by structural modifications on the berberine scaffold. In this review, recent advancements in the medicinal chemistry of berberine and its derivatives in the last few years (2016-2020) have been compiled to represent inclusive data associated with various biological activities of this alkaloid. The comprehensive structure-activity relationship studies along with molecular modelling and mechanistic studies have also been summarized. This article would be highly helpful for the scientific community to get better insight into medicinal research of berberine and become a compelling guide for the rational design of berberine based compounds.

Dietary berberine can ameliorate glucose metabolism disorder of Megalobrama amblycephala exposed to a high-carbohydrate diet

Blunt snout bream (Megalobrama amblycephala) were randomly assigned into three diets: normal-carbohydrate diet (NCD, 30% carbohydrate, w/w), high-carbohydrate diet (HCD, 43% carbohydrate), and HCB (HCD supplemented with 50 mg/kg berberine (BBR)). After 10 weeks' feeding trial, the results showed that higher levels of plasma glucose, triglyceride, and total cholesterol were observed in HCD-fed fish than in NCD-fed fish, while HCB feeding significantly ameliorated this effect. Moreover, HCB feeding remarkably reversed HCD-induced hepatic glycogen and lipid contents. In insulin signaling, BBR inclusion restored HCD-induced suppression of insulin receptor substrate mRNA expression and elevation of forkhead transcription factor 1 mRNA expression. In glucose metabolism, upregulated glucose transporter 2 and glycogen synthase mRNA expressions in the HCD group were observed compared to the NCD group. However, BBR adding reduced the mRNA expressions of glycogen synthase, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase and increased the transcriptional levels of glucose transporter 2 and pyruvate kinase. In lipid metabolism, BBR supplementation could reverse downregulated hepatic carnitine palmitoyl transferase I mRNA expression and upregulated hepatic acetyl-CoA carboxylase and fatty acid synthetase mRNA expressions in the HCD group. Taken together, it demonstrates that BBR could improve glucose metabolism of this species via enhancing liver's glycolysis and insulin signaling, while inhibiting liver's glycogen synthesis and gluconeogenesis. It also indicates that BBR could reduce the metabolic burden of the liver by inhibiting fat synthesis and promoting lipid decomposition, and then enhance fat uptake in peripheral tissues.

Berberine Promotes Induction of Immunological Tolerance to an Allograft via Downregulating Memory CD8+ T-Cells Through Altering the Gut Microbiota

Emerging evidence has linked the gut microbiota dysbiosis to transplant rejection while memory T-cells pose a threat to long-term transplant survival. However, it's unclear if the gut microbiome alters the formation and function of alloreactive memory T-cells. Here we studied the effects of berberine, a narrow-spectrum antibiotic that is barely absorbed when orally administered, on the gut microbiota, memory T-cells, and allograft survival. In this study, C57BL/6 mice transplanted with islets or a heart from BALB/c mice were treated orally with berberine. Allograft survival was observed, while spleen, and lymph node T-cells from recipient mice were analyzed using a flow cytometer. High-throughput sequencing and qPCR were performed to analyze the gut microbiota. CD8+ T-cells from recipients were cultured with the bacteria to determine potential T-cell memory cross-reactivity to a specific pathogen. We found that berberine suppressed islet allograft rejection, reduced effector CD8+CD44highCD62Llow and central memory CD8+CD44highCD62Lhigh T-cells (TCM), altered the gut microbiota composition and specifically lowered Bacillus cereus abundance. Further, berberine promoted long-term islet allograft survival induced by conventional costimulatory blockade and induced cardiac allograft tolerance as well. Re-colonization of B. cereus upregulated CD8+ TCM cells and reversed long-term islet allograft survival induced by berberine plus the conventional costimulatory blockade. Finally, alloantigen-experienced memory CD8+ T-cells from transplanted recipients rapidly responded to B. cereus in vitro. Thus, berberine prolonged allograft survival by repressing CD8+ TCM through regulating the gut microbiota. We have provided the first evidence that donor-specific memory T-cell generation is linked to a specific microbe and uncovered a novel mechanism underlying the therapeutic effects of berberine. This study may be implicated for suppressing human transplant rejection since berberine is already used in clinic to treat intestinal infections.

Impacts of Selected Dietary Nutrient Intakes on Skeletal Muscle Insulin Sensitivity and Applications to Early Prevention of Type 2 Diabetes

As the largest tissue in the body, skeletal muscle not only plays key roles in movement and glucose uptake and utilization but also mediates insulin sensitivity in the body by myokines. Insulin resistance in the skeletal muscle is a major feature of type 2 diabetes (T2D). A weakened response to insulin could lead to muscle mass loss and dysfunction. Increasing evidence in skeletal muscle cells, rodents, nonhuman primates, and humans has shown that restriction of caloric or protein intake positively mediates insulin sensitivity. Restriction of essential or nonessential amino acids was reported to facilitate glucose utilization and regulate protein turnover in skeletal muscle under certain conditions. Furthermore, some minerals, such as zinc, chromium, vitamins, and some natural phytochemicals such as curcumin, resveratrol, berberine, astragalus polysaccharide, emodin, and genistein, have been shown recently to protect skeletal muscle cells, mice, or humans with or without diabetes from insulin resistance. In this review, we discuss the roles of nutritional interventions in the regulation of skeletal muscle insulin sensitivity. A comprehensive understanding of the nutritional regulation of insulin signaling would contribute to the development of tools and treatment programs for improving skeletal muscle health and for preventing T2D.

Berberine Slows the Progression of Prediabetes to Diabetes in Zucker Diabetic Fatty Rats by Enhancing Intestinal Secretion of Glucagon-Like Peptide-2 and Improving the Gut Microbiota

BACKGROUND

Berberine is a plant alkaloid that has multiple beneficial effects against intestine inflammation. In our previous study, we have found that berberine also possesses an antidiabetic effect. However, whether berberine is useful in the prevention of type 2 diabetes mellitus (T2DM) through its effect on intestine endocrine function and gut microbiota is unclear.

AIM

To investigate the effects of berberine in the prevention of T2DM, as well as its effects on intestine GLP-2 secretion and gut microbiota in ZDF rats.

METHODS

Twenty Zucker Diabetic Fatty (ZDF) rats were fed a high-energy diet until they exhibited impaired glucose tolerance (IGT). The rats were then divided into two groups to receive berberine (100 mg/kg/d; berberine group) or vehicle (IGT group) by gavage for 3 weeks. Five Zucker Lean (ZL) rats were used as controls. Fasting blood glucose (FBG) was measured, an oral glucose tolerance test was performed, and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) was calculated. Intestinal expression of TLR-4, NF-κB, TNF-α, mucin, zona occludens-1 (ZO-1) and occludin were assessed (immunohistochemistry). Plasma levels and glutamine-induced intestinal secretion of glucagon-like peptide-1 (GLP-1) and GLP-2 were measured (enzyme-linked immunosorbent assay). The plasma lipopolysaccharide (LPS) level was measured. Fecal DNA extraction, pyrosequencing, and bioinformatics analysis were performed.

RESULTS

After 3 weeks of intervention, diabetes developed in all rats in the IGT group, but only 30% of rats in the berberine group. Treatment with berberine was associated with reductions in food intake, FBG level, insulin resistance, and plasma LPS level, as well as increases in fasting plasma GLP-2 level and glutamine-induced intestinal GLP-2 secretion. Berberine could increase the goblet cell number and villi length, and also reverse the suppressed expressions of mucin, occludin, ZO-1 and the upregulated expressions of TLR-4, NF-κB and TNF-α induced in IGT rats (P<0.05). Berberine also improved the structure of the gut microbiota and restored species diversity.

CONCLUSION

Berberine may slow the progression of prediabetes to T2DM in ZDF rats by improving GLP-2 secretion, intestinal permeability, and the structure of the gut microbiota.

Dietary supplementation with berberine improves growth performance and modulates the composition and function of cecal microbiota in yellow-feathered broilers

This study investigated the effect of berberine (BBR) on growth performance and composition and function of cecal microbiota in yellow-feathered broilers. A total of 360 1-day-old female broilers were assigned to 3 dietary treatments, each with 6 replicates of 20 birds. The dietary treatments consisted of a basal diet as negative control (NC), basal plus 200 mg/kg oxytetracycline calcium and 250 mg/kg nasiheptide as an antibiotic positive control (PC), and basal plus 250 mg/kg BBR. On day 21, 42, and 63, one chicken from each replicate was randomly selected for blood collection and cecal sampling. The 16S rRNA sequencing technology was used to analyze the community composition and function of cecal microbiota. Dietary supplementation with antibiotics or BBR increased the final body weight (BW) at day 63 and the average daily gain (ADG) during 1 to 21 d compared with the NC (P < 0.05). Supplementation with BBR improved the average daily feed intake (ADFI) at 22 to 42 d, 43 to 63 d, and 1 to 63 d (P < 0.05). Feed efficiency, indicated by feed to gain ratio (F/G), increased with PC during day 1 to 21 compared with NC (P < 0.05). The plasma concentrations of total protein at 42 d and uric acid at 21 d were increased, whereas creatine concentration at 63 d was decreased by BBR treatment (P < 0.05). The Chao 1 and Shannon index representing microbial α-diversity was reduced by BBR treatment (P < 0.05). The abundances of phylum Firmicutes and genera Lachnospiraceae, Lachnoclostridium, Clostridiales, and Intestinimonas were decreased, whereas the abundances of phylum Bacteroidetes and genus Bacteroides were increased with BBR treatment. Functional prediction of microbiota revealed that BBR treatment enriched pathways related to metabolism, organismal systems, and genetic information processing, especially DNA replication. The abundance of phylum Bacteroidetes, and genera Bacteroides and Lactobacillus in cecal contents were positively correlated with broiler growth performance. These results demonstrated dietary BBR supplementation improved the growth performance of yellow-feathered broilers, and was closely related to the significant changes in cecal microbiota composition.

Stachyose Improves the Effects of Berberine on Glucose Metabolism by Regulating Intestinal Microbiota and Short-Chain Fatty Acids in Spontaneous Type 2 Diabetic KKAy Mice

Berberine (BBR) has the beneficial effects of anti-inflammation, anti-bacteria, and anti-diabetes. The clinical application of BBR has been hindered by its poor gastrointestinal absorption. Stachyose (Sta), a prebiotic agent, improves the composition of gut microbiota and benefits for diabetes. We therefore investigated whether Sta improves the anti-diabetic actions of BBR using KKAy mice. Here, we find that the combination of BBR and Sta is more effective than BBR alone in blood glucose control, improvement of insulin resistance and islet functions, inflammatory mediators decrease, and maintenance of intestinal barrier integrity. Gut microbiota analysis demonstrates that both BBR and combined administration enhance the abundance of Bacteroidaceae and Akkermansiaceae and decrease Lachnospiraceae levels, whereas Akkermansiaceae elevation due to the administration of BBR with Sta is more significant than BBR alone. Interestingly, the proportion of Lactobacillaceae increases with combination treatment, but is diminished by BBR. Additionally, BBR with Sta significantly reduces the concentrations of fecal short-chain fatty acids compared to BBR. Collectively, these results indicate that the combination of BBR and Sta imparts better effects on the maintenance of glycemia and intestinal homeostasis than BBR alone by modulating gut microbiota and short-chain fatty acids, thereby providing a novel approach for the treatment of type 2 diabetes mellitus.

A Holistic View of Berberine Inhibiting Intestinal Carcinogenesis in Conventional Mice Based on Microbiome-Metabolomics Analysis

Berberine (BBR) has been reported that it has effects on inhibiting colorectal cancer (CRC). However, the mechanism of BBR on CRC also remains largely unknown. Herein, we investigated the therapeutic effects of BBR on CRC from the perspective of gut microbiota and metabolic alterations, which can provide a holistic view to understand the effects of BBR on CRC. First, azoxymethane (AOM)/dextran sodium sulfate (DSS) mouse was used as CRC animal model, then the degree of colorectal carcinogenesis in AOM/DSS mice with or without BBR administration was measured. The composition and abundance of gut microbiota was investigated by using 16S rRNA. Meanwhile, feces samples were analyzed with ¹H NMR spectroscopy to investigate the metabolic alterations. As a result, BBR significantly reduced intestinal tumor development with lower macroscopic polyps and ki-67 expression of intestinal tissue, and better colonic morphology in mice. Moreover, BBR altered the composition of gut microbiota in AOM/DSS mice obviously, which were characterized by a decrease of Actinobacteria and Verrucomicrobia significantly at the phylum level. At the genus level, it was able to suppress pathogenic species, such as f_Erysipelotrichaceae, Alistipes, and elevate some short-chain fatty acids (SCFA)-producing bacteria, including Alloprevotella, Flavonifractor, and Oscillibacter. Metabolic data further revealed that BBR induced metabolic changes in feces focus on regulating glycometabolism, SCFA metabolism and amino acid metabolism, which also provides evidence for alteration of the microbiota because these feces metabolites are the products of interactions between the host and the microbial community. This study showed that BBR induced alterations in microbiota and metabolic in AOM/DSS mice, which might providing new insight into the inhibition effects of BBR on CRC.

The effect of traditional Chinese medicine on gut microbiota in adults with type 2 diabetes: A protocol for systematic review and meta-analysis

BACKGROUND

Type 2 diabetes (T2DM), which is the major type of diabetes, accounts for more than 90% of all case of diabetes, and its pathogenesis remains inconclusive. Recent studies have revealed a significant role of gut microbiota in the onset and development of T2DM. Traditional Chinese medicine (TCM) has accumulated rich clinical experience in the treatment of T2DM for thousands of years and a large amount of studies have shown that TCM has the capacity of lowering blood glucose and modulating gut microbiota. The aim of this systematic review is to evaluate all randomized controlled trials on TCM for gut microbiota to assess the effectiveness and safety of TCM in T2DM patients.

METHODS

Seven electronic databases (Web of Science, PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, and VIP Information-Chinese Scientific Journal Database) will be searched from inception to present in the English and Chinese languages. Eligible randomized controlled trials evaluating the effect of TCM in T2DM patients, compared with western medicine, placebo or no intervention will be included in the study. The primary outcomes are the glucose metabolism and gut microbiota as well as its metabolites. The second outcomes are changes in weight, and changes in inflammatory markers. Two authors will independently select studies, extract data, and assess the quality of the studies by scanning the titles, abstracts, and full texts. The meta-analysis will be conducted using Review Manager version 5.3. The results will be presented as risk ratios for dichotomous data and adverse events, and as mean differences for continuous data.

RESULT

The study will provide a summary of current evidence for the treatment of T2DM from the perspective of gut microbiota by using TCM based on the outcome measures.

CONCLUSION

The systematic review will evaluate the efficacy of TCM in treating T2DM from the perspective of gut microbiota, providing current evidence and laying a foundation for further work in the field.

PROSPERO REGISTRATION NUMBER

CRD42020188043.

Role of gut microbiota in identification of novel TCM-derived active metabolites

Traditional Chinese Medicine (TCM) has been extensively used to ameliorate diseases in Asia for over thousands of years. However, owing to a lack of formal scientific validation, the absence of information regarding the mechanisms underlying TCMs restricts their application. After oral administration, TCM herbal ingredients frequently are not directly absorbed by the host, but rather enter the intestine to be transformed by gut microbiota. The gut microbiota is a microbial community living in animal intestines, and functions to maintain host homeostasis and health. Increasing evidences indicate that TCM herbs closely affect gut microbiota composition, which is associated with the conversion of herbal components into active metabolites. These may significantly affect the therapeutic activity of TCMs. Microbiota analyses, in conjunction with modern multiomics platforms, can together identify novel functional metabolites and form the basis of future TCM research.

Berberine alleviates type 2 diabetic symptoms by altering gut microbiota and reducing aromatic amino acids

OBJECTIVE

Berberine (BBR), which is extracted from traditional Chinese herb, is abundant in Coptis chinensis and Berberis vulgaris, with a treatment on type 2 diabetes mellitus (T2DM). However, its oral bioavailability is poor. Therefore, the ability of BBR to regulate gut microbiota and intestinal metabolites might exist. This study aimed to investigate changes in gut microbiota and intestinal metabolites, and to reveal the potential mechanism of BBR.

METHODS

To observe the role of gut microbiota in the treatment of T2DM by BBR, antibiotics intervened gut microbiota was used in this study, and the therapeutic effects of BBR were evaluated. A 16S rRNA gene sequencing approach was utilized to analyze gut microbiota alterations, and UHPLC-QTOF/MS-based untargeted metabolomics analysis of colon contents was used to identity differential intestinal metabolites. Finally, serum aromatic amino acids (AAAs) were absolutely quantified using LC/MS.

RESULTS

Inhibition of the blood glucose levels, and improvements in glucose tolerance and serum lipid parameters were observed in the BBR treated group. Type 2 diabetic symptoms in rats in the BA group (treated with antibotics and BBR) were alleviated. However, the therapeutical effects are weaker in the BA group compared with the BBR group, indicating that BBR can be used to treat type 2 diabetic rats immediately, and modulation of gut microbiota is related to the mechanism of BBR in the treatment of T2DM. The community richness and diversity of the gut microbiota were significantly increased by BBR, and the relative abundance of Bacteroidetes was increased in the BBR group, which was accompanied by a decreased relative abundance of Proteobacteria and Verrucomicrobia at the phylum level. At the family level, a probiotic Lactobacillaceae was significantly upregulated not only in the BBR group but also in the BA group and was negatively associated with the risk of T2DM. Metabolomic analysis of colon contents identified 55 differential intestinal metabolites between the BBR group and the model group. AAAs, including tyrosine, tryptophan and phenylalanine, were obviously decreased in the BBR group not only in the colon contents but also in the serum.

CONCLUSIONS

These results demonstrated that BBR could alleviate symptoms in type 2 diabetic rats by affecting gut microbiota composition and reducing the concentration of AAAs.

Effect of sulfate group on sulfated polysaccharides-induced improvement of metabolic syndrome and gut microbiota dysbiosis in high fat diet-fed mice

Sulfated polysaccharides were shown to benefit metabolic syndrome (MS) and gut microbiota, but the contribution of sulfate group remains unclear. In this study, sulfated polysaccharides from pacific abalone (AGSP) and its desulfated product (D-AGSP) were prepared, and the contribution of sulfate group was analyzed via in vitro and in vivo models. The result showed that sulfate group had no obvious effect on the reaction of AGSP with RAW 264.7 cells, but it affected the growth properties of gut microbes that able to utilize AGSP. The mice experiment showed that D-AGSP reduced weight gain, fat accumulation and lipid metabolism disorder in HFD-fed mice as well as AGSP, and no differences between them were found. Sequencing analysis showed that sulfate group influenced AGSP-induced alterations of the gut microbiota at higher taxonomic levels, some of which had close correlation with the improvement of physiological index. These results implied that sulfate group may partially determine the activities of polysaccharides via gut microbiota-mediated pathway, but the exact mechanisms need further research.

The "Treatise on the spleen and stomach" (Pí Wèi Lùn) as the first record of multiple sclerosis in the medical literature - A hypothesis based on the analysis of clinical presentation and herbal medicine

Background

The “Treatise on the spleen and stomach” (Pí Wèi Lùn) is the work of the scholar and physician Li Gao (Jin-Yuan dynasties, 1115–1368 C.E., China). Li Gao described a clinical presentation that today would fall under the diagnosis of Multiple Sclerosis (MS) and proposed the treatment with herbal medicine and nutritional guidelines. The PWL is well known for its application in the treatment of MS and autoimmune conditions. However, this theoretical “MS” has not yet been analyzed through a scientific investigation, and research on its herbal formulations for MS is scant.

Methods

We analyzed the PWL “MS” clinical presentation considering biomedical diagnostic criteria and neurological correlates. To support our review, we searched Pubmed for studies on the PWL main herbal formulas and their herbs/isolates used for the believed “MS” which treated experimental autoimmune encephalomyelitis (EAE)/MS.

Results

We found a very close correlation between the PWL “MS” and the current MS diagnosis. Twenty four studies on the herbs-isolates showed significant amelioration of EAE, neuronal damage, and demyelination.

Discussion

Collectively, Astragali radix, Ginseng radix, Glycyrrhizae radix, and berberine containing Phellodendri cortex reduced the severity of EAE through different signaling pathways and mechanisms of action. These herbs provided a wide range of properties such as anti-inflammatory, anti-oxidant, anti-microglial activation, anti-infiltration of leukocytes, apoptotic/anti-apoptotic balance, and neuronal protection.

Conclusion

Our review proposes that the PWL is the first record of MS in the medical literature. Its formulas and herbs-isolates offer a fertile area for MS research and an invaluable potential for its treatment.

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We propose that the Pí Wèi Lùn is the first record of MS in the medical literature.

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All twenty four studies on the PWL’s selected herbs/isolates showed improvement of EAE.

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Different signaling pathways/mechanisms of action provided synergistic properties.

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In the PWL, the gastrointestinal system is key for MS and science supports it.

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The PWL offers a fertile area of research and enormous potential for MS treatment.

Altered nutrient status reprograms host inflammation and metabolic health via gut microbiota

The metabolism of macro- and micronutrients is a complex and highly regulated biological process. An imbalance in the metabolites and their signaling networks can lead to nonresolving inflammation and consequently to the development of chronic inflammatory-associated diseases. Therefore, identifying the accumulated metabolites and altered pathways during inflammatory disorders would not only serve as "real-time" markers but also help in the development of nutritional therapeutics. In this review, we explore recent research that has delved into elucidating the effects of carbohydrate/calorie restriction, protein malnutrition, lipid emulsions and micronutrient deficiencies on metabolic health and inflammation. Moreover, we describe the integrated stress response in terms of amino acid starvation and lipemia and how this modulates new age diseases such as inflammatory bowel disease and atherosclerosis. Lastly, we explain the latest research on metaflammation and inflammaging. This review focuses on multiple signaling pathways, including, but not limited to, the FGF21-β-hydroxybutryate-NLRP3 axis, the GCN2-eIF2α-ATF4 pathway, the von Hippel-Lindau/hypoxia-inducible transcription factor pathway and the TMAO-PERK-FoxO1 axis. Additionally, throughout the review, we explain how the gut microbiota responds to altered nutrient status and also how antimicrobial peptides generated from nutrient-based signaling pathways can modulate the gut microbiota. Collectively, it must be emphasized that metabolic starvation and inflammation are strongly regulated by both environmental (i.e., nutrition, gut microbiome) and nonenvironmental (i.e., genetics) factors, which can influence the susceptibility to inflammatory disorders.

The effect of Berberine on weight loss in order to prevent obesity: A systematic review

This study provides a critical overview of experimental studies in vitro, in humans, and in animals that evaluated the efficacy of Berberine and its effect on management of obesity and the related metabolic consequences. As a result of this review, we summarized the effects of Berberine in different models and the related mechanism of actions. In preclinical models, Berberine demonstrates that it affects gut microbiota by reducing diversity of microbes starting at a dosage of 100 mg/kg/day. Moreover, in animal models, Berberine explicates an action on glucose through the inhibition of α-glycosidase at a dose of 200 mh/kg/day. Berberine is also known to be effective against differentiation of adipocytes through a decrease in LXRs, PPARs, and SREBPs expression at 150 mg/kg/day. Other mechanism ascribed to Berberine are related to its inhibition of hepatic gluconeogenesis through the Phospheoenolpyruvate carboxykinase (PEPCK), Glucose-6-phosphate (G6Pase) and AMP-activated protein kinase (AMPK). Furthermore, Berberine (associated to Red Yeast Rice) is effective in decreasing lipid levels in rats, which consequently lowers the change of weight gain at dosage of 40 mg/kg to 380 mg/kg/day. All the above preclinical data are confirmed in human studies where Berberine can modulate the diversity of gut microbes at the dose of 500 mg/day. In addition, Berberine is found to have a beneficial impact on gene regulation for the absorption of cholesterol at a daily dose of 300 mg in humans, an amelioration on glucose accumulation at 1.0 g daily dose was also observed. For all these reasons, this review gives an important good account of the impact of Berberine in obesity treatment and prevention.

Reply to Comment on Watanabe, A.; Kadota, Y.; Yokoyama, H.; Tsuruda, S.; Kamio, R.; Tochio, T.; Shimomura, Y.; Kitaura, Y. Experimental Determination of the Threshold Dose for Bifidogenic Activity of Dietary 1-Kestose in Rats. Foods 2020, 9, 4

The manuscript entitled "Comment on Experimental Determination of the Threshold Dose for Bifidogenic Activity of Dietary 1-Kestose in Rats" by Shen et al [...].

Sennoside A restores colonic barrier function through protecting colon enterocytes from ROS-induced mitochondrial damage in diet-induced obese mice

The intestinal barrier dysfunction is closely implicated in low-grade chronic inflammation for insulin resistance in diet-induced obesity (DIO). It is generally believed that degradation of colon enterocytes contributes to intestinal barrier dysfunction in the pathological process of obesity. Sennoside A (SA) is reported to improve metabolic disorders, but the effect and mechanism of SA on colonic barrier function of DIO remains unknown. In this study, SA was found to restore colonic barrier function by protecting the continuity and integrity of colon enterocytes in DIO mice. An increase in mRNA expression of tight junction proteins Occludin, Claudin-2 and ZO-1 provides another mechanism of restoring colonic barrier function in SA-treated group. In the research of mechanism, mitophagy was inhibited by SA via a protection of mitochondrial structure and function in colon. A reduction was found in production of reactive oxygen species (ROS) in the colon, and the benefical effect was attributed to an inhibition of activity in complex I and III with a reduction of protein expression and an increase of Mn-SOD activity. The results indicate that SA can restores colonic barrier function through protecting colon enterocytes from ROS-induced mitochondrial damage in DIO mice.

Berberine pharmacology and the gut microbiota: A hidden therapeutic link

Berberine is a natural pentacyclic isoquinoline alkaloid that has been isolated as the principal component of many popular medicinal plants such as the genus Berberis, Coptis and Hydrastis. The multifunctional nature of berberine as a therapeutic agent is an attribute of its diverse effects on enzymes, receptors and cell signalling pathways. Through specific and general antioxidant and anti-inflammatory mechanisms, its polypharmacology has been established. Intriguingly, this is despite the poor bioavailability of berberine in animal models and hence begging the question how it induces its reputed effects in vivo. A growing evidence now suggest the role of the gut microbiota, the so-called the hidden organ, as targets for the multifunctional role of berberine. Evidences are herein scrutinised to show that the structural and numerical changes in the gut microbiota under pathological conditions are reversed by berberine. Examples in the pharmacokinetics field, obesity, hyperlipidaemia, diabetes, cancer, inflammatory disease conditions, etc. are used to show the link between the gut microbiota and the polypharmacology of berberine.

Polycystic ovary syndrome management: a review of the possible amazing role of berberine

PURPOSE

The therapy of polycystic ovary syndrome (PCOS) is based on synthetic hormones associated with lifestyle changes, but these therapies cannot be taken continuously, especially by women who would like to become pregnant. Thus, nutraceutical compounds were investigated as possible agents for treatment of PCOS. Berberine is shown to be effective against insulin resistance and obesity, particularly against visceral adipose tissue (VAT). Because of these properties, researchers theorized that berberine could be effective in PCOS treatment.

METHODS

The aim of this narrative review was to assess the state of the art about the use of berberine in PCOS management.

RESULTS

This review included 5 eligible studies. Despite the number of studies considered being low, the number of women studied is high (1078) and the results are interesting. Two authors find out that berberine induced a redistribution of adipose tissue, reducing VAT in the absence of weight loss and improved insulin sensitivity, quite like metformin. One author demonstrated that berberine improved the lipid pattern. Moreover, three authors demonstrated that berberine improved insulin resistance in theca cells with an improvement of the ovulation rate per cycle, so berberine is also effective on fertility and live birth rates.

CONCLUSIONS

Finally, berberine is safe to use in premenopausal women who want to get pregnant and showed few side effects in all the cited studies. In conclusion, the use of berberine for PCOS is safe and promising, even if more studies are needed to create a consensus about the dosage of berberine useful for long-term therapy.

Berberine in the treatment of metabolism-related chronic diseases: A drug cloud (dCloud) effect to target multifactorial disorders

Berberine (BBR) is a multi-target drug (MTD) that has proven effective in the treatment of metabolism-related chronic diseases (CDs). However, the mode of action (MOA) of BBR remains to be clarified. At a cellular level, the inhibitory effect of BBR on mitochondrial enzymes is probably responsible for many of its biological activities, including the activation of low-density lipoprotein receptor (LDLR), AMP-activated protein kinase (AMPK) and insulin receptor (InsR); these biological activities contribute to ameliorate peripheral blood metabolic profiles, e.g. by reducing plasma lipids and glucose levels, thus improving signs and symptoms of metabolic disorders. In this perspective, BBR acts as a targeted therapy. However, it also exerts pleiotropic systemic activities on some root causes of CDs that include antioxidant / anti-inflammatory effects and modifications of gut microbiota composition and metabolism, which may also contribute to its disease-modifying effects. After reviewing the different MOA of BBR, here we propose that BBR acts through a drug-cloud (dCloud) mechanism, as different to a drug-target effect. The dCloud here is defined as a group of terminal molecular events induced by the drug (or/and related metabolites), as well as the network connections among them. In this scenario, the therapeutic efficacy of BBR is the result of its dCloud effect acting on symptoms/signs as well as on root causes of the diseases. The dCloud concept is applicable to other established MTDs, such as aspirin, metformin, statins as well as to nutrient starvation, thus providing a novel instrument for the design of effective therapies against multifactorial metabolism-related CDs.

Berberine for prevention of dementia associated with diabetes and its comorbidities: A systematic review

BACKGROUND

A growing number of epidemiological studies indicate that metabolic syndrome (MetS) and its associated features play a key role in the development of certain degenerative brain disorders, including Alzheimer's disease and vascular dementia. Produced by several different medicinal plants, berberine is a bioactive alkaloid with a wide range of pharmacological effects, including antidiabetic effects. However, it is not clear whether berberine could prevent the development of dementia in association with diabetes.

OBJECTIVE

To give an overview of the therapeutic potential of berberine as a treatment for dementia associated with diabetes.

SEARCH STRATEGY

Database searches A and B were conducted using PubMed and ScienceDirect. In search A, studies on berberine's antidementia activities were identified using "berberine" and "dementia" as search terms. In search B, recent studies on berberine's effects on diabetes were surveyed using "berberine" and "diabetes" as search terms.

INCLUSION CRITERIA

Clinical and preclinical studies that investigated berberine's effects associated with MetS and cognitive dysfunction were included.

DATA EXTRACTION AND ANALYSIS

Data from studies were extracted by one author, and checked by a second; quality assessments were performed independently by two authors.

RESULTS

In search A, 61 articles were identified, and 22 original research articles were selected. In search B, 458 articles were identified, of which 101 were deemed relevant and selected. Three duplicates were removed, and a total of 120 articles were reviewed for this study. The results demonstrate that berberine exerts beneficial effects directly in the brain: enhancing cholinergic neurotransmission, improving cerebral blood flow, protecting neurons from inflammation, limiting hyperphosphorylation of tau and facilitating β-amyloid peptide clearance. In addition, evidence is growing that berberine is effective against diabetes and associated disorders, such as atherosclerosis, cardiomyopathy, hypertension, hepatic steatosis, diabetic nephropathy, gut dysbiosis, retinopathy and neuropathy, suggesting indirect benefits for the prevention of dementia.

CONCLUSION

Berberine could impede the development of dementia via multiple mechanisms: preventing brain damages and enhancing cognition directly in the brain, and indirectly through alleviating risk factors such as metabolic dysfunction, and cardiovascular, kidney and liver diseases. This study provided evidence to support the value of berberine in the prevention of dementia associated with MetS.

The Microbiome and Aging

Aging is a natural process of organismal decay that underpins the development of myriad diseases and disorders. Extensive efforts have been made to understand the biology of aging and its regulation, but most studies focus solely on the host organism. Considering the pivotal role of the microbiota in host health and metabolism, we propose viewing the host and its microbiota as a single biological entity whose aging phenotype is influenced by the complex interplay between host and bacterial genetics. In this review we present how the microbiota changes as the host ages, but also how the intricate relationship between host and indigenous bacteria impacts organismal aging and life span. In addition, we highlight other microbiota-dependent mechanisms that potentially regulate aging, and present experimental animal models for addressing these questions. Importantly, we propose microbiome dysbiosis as an additional hallmark and biomarker of aging.

Therapeutic Mechanisms of Herbal Medicines Against Insulin Resistance: A Review

Insulin resistance is a condition in which insulin sensitivity is reduced and the insulin signaling pathway is impaired. Although often expressed as an increase in insulin concentration, the disease is characterized by a decrease in insulin action. This increased workload of the pancreas and the consequent decompensation are not only the main mechanisms for the development of type 2 diabetes (T2D), but also exacerbate the damage of metabolic diseases, including obesity, nonalcoholic fatty liver disease, polycystic ovary syndrome, metabolic syndrome, and others. Many clinical trials have suggested the potential role of herbs in the treatment of insulin resistance, although most of the clinical trials included in this review have certain flaws and bias risks in their methodological design, including the generation of randomization, the concealment of allocation, blinding, and inadequate reporting of sample size estimates. These studies involve not only the single-flavored herbs, but also herbal formulas, extracts, and active ingredients. Numerous of in vitro and in vivo studies have pointed out that the role of herbal medicine in improving insulin resistance is related to interventions in various aspects of the insulin signaling pathway. The targets involved in these studies include insulin receptor substrate, phosphatidylinositol 3-kinase, glucose transporter, AMP-activated protein kinase, glycogen synthase kinase 3, mitogen-activated protein kinases, c-Jun-N-terminal kinase, nuclear factor-kappaB, protein tyrosine phosphatase 1B, nuclear factor-E2-related factor 2, and peroxisome proliferator-activated receptors. Improved insulin sensitivity upon treatment with herbal medicine provides considerable prospects for treating insulin resistance. This article reviews studies of the target mechanisms of herbal treatments for insulin resistance.

Long non-coding RNAs are emerging targets of phytochemicals for cancer and other chronic diseases

The long non-coding RNAs (lncRNAs) are the crucial regulators of human chronic diseases. Therefore, approaches such as antisense oligonucleotides, RNAi technology, and small molecule inhibitors have been used for the therapeutic targeting of lncRNAs. During the last decade, phytochemicals and nutraceuticals have been explored for their potential against lncRNAs. The common lncRNAs known to be modulated by phytochemicals include ROR, PVT1, HOTAIR, MALAT1, H19, MEG3, PCAT29, PANDAR, NEAT1, and GAS5. The phytochemicals such as curcumin, resveratrol, sulforaphane, berberine, EGCG, and gambogic acid have been examined against lncRNAs. In some cases, formulation of phytochemicals has also been used. The disease models where phytochemicals have been demonstrated to modulate lncRNAs expression include cancer, rheumatoid arthritis, osteoarthritis, and nonalcoholic fatty liver disease. The regulation of lncRNAs by phytochemicals can affect multi-steps of tumor development. When administered in combination with the conventional drugs, phytochemicals can also produce synergistic effects on lncRNAs leading to the sensitization of cancer cells. Phytochemicals target lncRNAs either directly or indirectly by affecting a wide variety of upstream molecules. However, the potential of phytochemicals against lncRNAs has been demonstrated mostly by preclinical studies in cancer models. How the modulation of lncRNAs by phytochemicals produce therapeutic effects on cancer and other chronic diseases is discussed in this review.

Fecal Microbiota of Diarrhea-Predominant Irritable Bowel Syndrome Patients Causes Hepatic Inflammation of Germ-Free Rats and Berberine Reverses It Partially

Effects of the microbiome associated with diarrhea-predominant irritable bowel syndrome (IBS-D) on the gut have been reported, but no study has reported the effects of the IBS-D gut microbiome on the liver. We transplanted the fecal microbiota from an IBS-D patient and from a healthy volunteer to GF rats. The hepatic inflammation, serum biochemical parameters and metabolome, fecal microbiota profile, fecal short-chain fatty acids (SCFAs), and correlations among them before and after berberine intervention were assessed. Compared with the healthy control fecal microbiome transplantation (FMT) rats, the fecal microbiota of IBS-D patients induces significant Kupffer cell hyperplasia, hepatic sinusoid hypertrophy, and elevated levels of hepatic tumor necrosis factor-α and interferon-γ and decreases the synthesis of ALB in GF rats. This is possibly related to Faecalibacterium and Bifidobacterium attributable to fecal formate, acetate, and propionate levels, which are associated with the host linoleic acid pathway. Berberine can partially reverse the Kupffer cell hyperplasia, Faecalibacterium, fecal formate, acetate, and propionate by modulating the gut microbiome composition. These results may imply that IBS-D not only is an intestinal functional disorder but can cause liver inflammation, thus providing some implications regarding the clinical cognition and treatment of IBS-D.

Berberine in Cardiovascular and Metabolic Diseases: From Mechanisms to Therapeutics

Cardiovascular and metabolic diseases (CVMD) are the leading causes of death worldwide, underscoring the urgent necessity to develop new pharmacotherapies. Berberine (BBR) is an eminent component of traditional Chinese and Ayurvedic medicine for more than 2000 years. Recently, BBR has attracted much interest for its pharmacological actions in treating and/or managing CVMD. Recent discoveries of basic, translational and clinical studies have identified many novel molecular targets of BBR (such as AMPK, SIRT1, LDLR, PCSK9, and PTP1B) and provided novel evidences supporting the promising therapeutic potential of BBR to combat CVMD. Thus, this review provides a timely overview of the pharmacological properties and therapeutic application of BBR in CVMD, and underlines recent pharmacological advances which validate BBR as a promising lead drug against CVMD.

The anti-hyperglycemia effects of Rhizoma Coptidis alkaloids: A systematic review of modern pharmacological studies of the traditional herbal medicine

Hyperglycemia is a common endocrine system disease, which seriously affects people's health with a increasing morbidity in recent years. Rhizoma Coptidis (RC), one of the most commonly used traditional Chinese medicines, has been applied to treat diabetes in clinic for thousands of years. Since scientists demonstrated that alkaloids from RC owned the amazing anti-hyperglycemia activities 30 years ago, these compounds have been widely used for the treatment of diabetes and hyperglycemia with unconspicuous toxicities and side effects. With the help of molecular biology, immunology and other techniques, the mechanisms about anti-hyperglycemia effect of RC alkaloids have been extensively discussed. Numerous studies showed that RC alkaloids balanced the glucose homeostasis not only by widely recognizing insulin resistance pathways, but also by promoting insulin secretion, regulating intestinal hormones, ameliorating gut microbiota structures and many other ways. In this review, we combine the latest advances and systematically summarize the mechanisms of RC alkaloids in treating hyperglycemia and diabetic nephropathy to provide a deeper understanding of these natural alkaloids. In addition, the important role of gut microbiota associated with the glucose metabolism is also reviewed.

Gut Microbiota, a Potential New Target for Chinese Herbal Medicines in Treating Diabetes Mellitus

The gut microbiota, as an important factor affecting host health, plays a significant role in the occurrence and development of diabetes mellitus (DM), and the mechanism may be related to excessive endotoxins, altered short-chain fatty acids (SCFAs), and disordered bile acid metabolism. Traditional Chinese medicine (TCM) has a long history of treating DM, but its mechanism is not very clear. Recent research has suggested that Chinese herbal medicine can improve glucose metabolism by remodeling the gut microbiota, which opens new avenues for further research on hypoglycemic mechanisms. This review presents the recent progress of Chinese herbs, herbal extracts, and herbal compound preparations in treating DM through regulating the gut microbiota and summarizes the main mechanisms involved, namely, anti-inflammatory and antioxidative effects, protecting the intestinal barrier and inhibiting lipotoxicity. In addition, some suggestions for improvement are also proposed.

Human Breast-Milk Feeding Enhances the Humoral and Cell-Mediated Immune Response in Neonatal Piglets

Background

The benefits of breastfeeding infants are well characterized, including those on the immune system. However, determining the mechanism by which human breast milk (HBM) elicits effects on immune response requires investigation in an appropriate animal model.

Objective

The primary aim of this study was to develop a novel porcine model and to determine the differential effects of feeding HBM and a commercial milk formula (MF) on immune response and gastrointestinal microbial colonization in a controlled environment.

Methods

Male piglets were fed HBM (n = 26) or MF (n = 26) from day 2 through day 21. Piglets were vaccinated (n = 9/diet group) with cholera toxin and cholera toxin subunit B (CTB) and tetanus toxoid at 21 d or were fed placebo (n = 6/diet group) and then weaned to a standard solid diet at the age of 21 d. Humoral and cell-mediated immune responses were assessed from blood on days 35 and 48. Immune response was further examined from tissues, including mesenteric lymph nodes (MLNs), Peyer's patches (PPs), and spleen. The colonization of gut microbiota was characterized from feces on days 16 and 49.

Results

Serum antibody titers in piglets fed HBM were 4-fold higher (P < 0.05) to CTB and 3-fold higher (P < 0.05) to tetanus toxoid compared with piglets fed MF on day 48. Compared with MF, the numbers of immunoglobulin A antibody-producing cells to CTB were 13-fold higher (P < 0.05) in MLNs and 11-fold higher (P < 0.05) in PPs in the HBM diet group on day 51. In addition, significantly increased T cell proliferation was observed in the HBM group relative to the MF group. Furthermore, microbial diversity in the HBM group was lower (P < 0.05) than in the MF group.

Conclusions

This porcine model appears to be valid for studying the effects of early postnatal diet on immune responses and the gastrointestinal microbiome. Our results lay the groundwork for future studies defining the role of infant diet on microbiota and immune function.

Prebiotic Potential of Herbal Medicines Used in Digestive Health and Disease

INTRODUCTION

The prebiotic potential of herbal medicines has been scarcely studied.

METHODS

The authors therefore used anaerobic human fecal cultivation to investigate whether three herbal medicines commonly used in gastrointestinal health and disease in Ayurveda alter the growth and abundance of specific bacterial species.

RESULTS

Profiling of cultures supplemented with Glycyrrhiza glabra, Ulmus rubra, or triphala formulation by 16S rDNA sequencing revealed profound changes in diverse taxa in human gut microbiota. Principal coordinate analysis highlights that each herbal medicine drives the formation of unique microbial communities. The relative abundance of approximately one-third of the 299 species profiled was altered by all 3 medicines, whereas additional species displayed herb-specific alterations. Herb supplementation increased the abundance of many bacteria known to promote human health, including Bifidobacterium spp., Lactobacillus spp., and Bacteroides spp. Herb supplementation resulted in the reduced relative abundance of many species, including potential pathogens such as Citrobacter freundii and Klebsiella pneumoniae. Herbal medicines induced blooms of butyrate- and propionate-producing species. U. rubra and triphala significantly increased the relative abundance of butyrate-producing bacteria, whereas G. glabra induced the largest increase in propionate-producing species. To achieve greater insight into the mechanisms through which herbal medicines alter microbial communities, the authors assessed the shifts in abundance of glycosyl hydrolase families induced by each herbal medicine. Herb supplementation, particularly G. glabra, significantly increased the representation and potential expression of several glycosyl hydrolase families.

DISCUSSION

These studies are novel in highlighting the significant prebiotic potential of medicinal herbs and suggest that the health benefits of these herbs are due, at least in part, to their ability to modulate the gut microbiota in a manner predicted to improve colonic epithelium function, reduce inflammation, and protect from opportunistic infection. Forthcoming studies in human clinical trials will test the concordance of the results generated in vitro and the predictions made by genome analyses.