Berberine Ameliorates Hepatic Steatosis and Suppresses Liver and Adipose Tissue Inflammation in Mice with Diet-induced Obesity

Combination of Berberine with Resveratrol Improves the Lipid-Lowering Efficacy

The natural compound berberine has been reported to exhibit anti-diabetic activity and to improve disordered lipid metabolism. In our previous study, we found that such compounds upregulate expression of sirtuin 1—a key molecule in caloric restriction, it is, therefore, of great interest to examine the lipid-lowering activity of berberine in combination with a sirtuin 1 activator resveratrol. Our results showed that combination of berberine with resveratrol had enhanced hypolipidemic effects in high fat diet-induced mice and was able to decrease the lipid accumulation in adipocytes to a level significantly lower than that in monotherapies. In the high fat diet-induced hyperlipidemic mice, combination of berberine (30 mg/kg/day, oral) with resveratrol (20 mg/kg/day, oral) reduced serum total cholesterol by 27.4% ± 2.2%, and low-density lipoprotein-cholesterol by 31.6% ± 3.2%, which was more effective than that of the resveratrol (8.4% ± 2.3%, 6.6% ± 2.1%) or berberine (10.5% ± 1.95%, 9.8% ± 2.58%) monotherapy (p < 0.05 for both). In 3T3-L1 adipocytes, the treatment of 12 µmol/L or 20 µmol/L berberine combined with 25 µmol/L resveratrol showed a more significant inhibition of lipid accumulation observed by Oil red O stain compared with individual compounds. Moreover, resveratrol could increase the amount of intracellular berberine in hepatic L02 cells. In addition, the combination of berberine with resveratrol significantly increases the low-density-lipoprotein receptor expression in HepG2 cells to a level about one-fold higher in comparison to individual compound. These results implied that the enhanced effect of the combination of berberine with resveratrol on lipid-lowering may be associated with upregulation of low-density-lipoprotein receptor, and could be an effective therapy for hyperlipidemia in some obese-associated disease, such as type II diabetes and metabolic syndrome.

Expression of STING Is Increased in Liver Tissues From Patients With NAFLD and Promotes Macrophage-Mediated Hepatic Inflammation and Fibrosis in Mice

BACKGROUND & AIMS

Transmembrane protein 173 (TMEM173 or STING) signaling by macrophage activates the type I interferon-mediated innate immune response. The innate immune response contributes to hepatic steatosis and non-alcoholic fatty liver disease (NAFLD). We investigated whether STING regulates diet-induced in hepatic steatosis, inflammation, and liver fibrosis in mice.

METHODS

Mice with disruption of Tmem173 (STING^gt) on a C57BL/6J background, mice without disruption of this gene (controls), and mice with disruption of Tmem173 only in myeloid cells were fed a standard chow diet, a high-fat diet (HFD; 60% fat calories), or a methionine- and choline-deficient diet (MCD). Liver tissues were collected and analyzed by histology and immunohistochemistry. Bone marrow cells were isolated from mice, differentiated into macrophages, and incubated with 5,6-dimethylxanthenone-4-acetic acid (DMXAA; an activator of STING) or cyclic guanosine monophosphate-adenosine monophosphate (cGAMP). Macrophages or their media were applied to mouse hepatocytes or human hepatic stellate cells (LX2) cells, which were analyzed for cytokine expression, protein phosphorylation, and fat deposition (by oil red O staining after incubation with palmitate). We obtained liver tissues from patients with and without NAFLD and analyzed these by immunohistochemistry.

RESULTS

Non-parenchymal cells of liver tissues from patients with NAFLD had higher levels of STING than cells of liver tissues from patients without NAFLD. STING^gt mice and mice with disruption only in myeloid cells developed less severe hepatic steatosis, inflammation, and/or fibrosis after the HFD or MCD than control mice. Levels of phosphorylated c-Jun N-terminal kinase and p65 and mRNAs encoding tumor necrosis factor and interleukins 1B and 6 (markers of inflammation) were significantly lower in liver tissues from STING^gt mice vs control mice after the HFD or MCD. Transplantation of bone marrow cells from control mice to STING^gt mice restored the severity of steatosis and inflammation after the HFD. Macrophages from control, but not STING^gt, mice increased markers of inflammation in response to lipopolysaccharide and cGAMP. Hepatocytes and stellate cells cocultured with STING^gt macrophages in the presence of DMXAA or incubated with the medium collected from these macrophages had decreased fat deposition and markers of inflammation compared with hepatocytes or stellate cells incubated with control macrophages.

CONCLUSIONS

Levels of STING were increased in liver tissues from patients with NAFLD and mice with HFD-induced steatosis. In mice, loss of STING from macrophages decreased the severity of liver fibrosis and the inflammatory response. STING might be a therapeutic target for NAFLD.

Berberine Ameliorates Periodontal Bone Loss by Regulating Gut Microbiota

Postmenopausal osteoporosis (PMO) is a risk factor for periodontitis, and current therapeutics against PMO prevent the aggravated alveolar bone loss of periodontitis in estrogen-deficient women. Gut microbiota is recognized as a promising therapeutic target for PMO. Berberine extracted from Chinese medicinal plants has shown its effectiveness in the treatment of metabolic diseases such as obesity and diabetes via regulating gut microbiota. Here, we hypothesize that berberine ameliorates periodontal bone loss by improving the intestinal barriers by regulating gut microbiota under an estrogen-deficient condition. Experimental periodontitis was established in ovariectomized (OVX) rats, and the OVX-periodontitis rats were treated with berberine for 7 wk before sacrifice for analyses. Micro–computed tomography and histologic analyses showed that berberine treatment significantly reduced alveolar bone loss and improved bone metabolism of OVX-periodontitis rats as compared with the vehicle-treated OVX-periodontitis rats. In parallel, berberine-treated OVX-periodontitis rats harbored a higher abundance of butyrate-producing gut microbiota with elevated butyrate generation, as demonstrated by 16S rRNA sequencing and high-performance liquid chromatography analysis. Berberine-treated OVX-periodontitis rats consistently showed improved intestinal barrier integrity and decreased intestinal paracellular permeability with a lower level of serum endotoxin. In parallel, IL-17A-related immune responses were attenuated in berberine-treated OVX-periodontitis rats with a lower serum level of proinflammatory cytokines and reduced IL-17A+ cells in alveolar bone as compared with vehicle-treated OVX-periodontitis rats. Our data indicate that gut microbiota is a potential target for the treatment of estrogen deficiency–aggravated periodontal bone loss, and berberine represents a promising adjuvant therapeutic by modulating gut microbiota.

Paradoxical Protective Effect of Perfluorooctanesulfonic Acid Against High-Fat Diet-Induced Hepatic Steatosis in Mice

Perfluorooctanesulfonic acid (PFOS) is a persistent organic pollutant with worldwide bioaccumulation due to a very long half-life. Perfluorooctanesulfonic acid exposure results in significant hepatic effects including steatosis, proliferation, hepatomegaly, and in rodents, carcinogenesis. The objective of this study was to determine whether PFOS exposure exacerbates nonalcoholic fatty liver disease and nonalcoholic steatohepatitis pathogenesis. Eight-week-old male C57BL/6 J mice (n = 5 per group) were fed ad libitum normal chow diet (ND) alone, 60% high-fat diet (HFD) alone, ND + PFOS, and HFD + PFOS (0.0001% w/w (1 mg/kg) of PFOS) for 6 weeks. Both HFD alone and the ND + PFOS treatment induced significant adiposity and hepatomegaly, but the HFD + PFOS treatment showed a marked protection. Oil Red O staining and quantitative analysis of hepatic lipid content revealed increased hepatic steatosis in ND + PFOS and in HFD alone fed mice, which was prevented in HFD + PFOS treatment. Further studies revealed that ND + PFOS treatment significantly affected expression of lipid trafficking genes to favor steatosis, but these changes were absent in HFD + PFOS group. Specifically, expression of CD36, the major lipid importer in the cells, and peroxisome proliferator-activated receptor gamma (PPARγ), its major regulator, were induced in HFD + no treatment (NT) and ND + PFOS-fed mice but remained unchanged in HFD + PFOS mice. In conclusion, these data indicate that coadministration of PFOS with HFD mitigates steatosis and hepatomegaly induced by HFD and that by PFOS fed in ND diet via regulation of cellular lipid import machinery. These findings suggest dietary lipid content be considered when performing risk management of PFOS in humans and the elucidation of PFOS-induced hepatotoxicity.

Delphinidin Ameliorates Hepatic Triglyceride Accumulation in Human HepG2 Cells, but Not in Diet-Induced Obese Mice

Anthocyanin consumption is linked to benefits in obesity-related metabolic alterations and non-alcoholic fatty liver disease (NAFLD), though the functional role of delphinidin (Dp) is yet to be established. Therefore, this study examined the effects of Dp on metabolic alterations associated with NAFLD, and molecular mechanisms in HepG2 cells and diet-induced obese mice. Cells incubated with palmitate to induce lipid accumulation, concomitantly treated with Dp, reduced triglyceride accumulation by ~53%, and downregulated gene expression of CPT1A, SREBF1, and FASN without modifying AMP-activated protein kinase (AMPK) levels. C57BL/6Nhsd mice were fed a standard diet (control) or a high-fat/high-carbohydrate diet (HFHC) for 16 weeks. Mice in the HFHC group were subdivided and treated with Dp (HFHC-Dp, 15 mg/kg body weight/day) or a vehicle for four weeks. Dp did not affect body weight, energy intake, hyperglycemia, insulin resistance, or histological abnormalities elicited by the HFHC diet. Furthermore, the messenger RNA (mRNA) expressions of Acaca, and Fasn in hepatic or epididymal adipose tissue, and the hepatic sirtuin 1 (SIRT1)/liver kinase B1 (LKB1)/AMPK and proliferator-activated receptor alpha (PPARα) signaling axis did not significantly change due to the HFHC diet or Dp. In summary, Dp effectively reduced triglyceride accumulation in vitro through the modulation of lipid metabolic gene expression. However, a dose of Dp administrated in mice simulating the total daily anthocyanin intake in humans had no effect on either metabolic alterations or histological abnormalities associated with HFHC diets.

Berberine ameliorates blockade of autophagic flux in the liver by regulating cholesterol metabolism and inhibiting COX2-prostaglandin synthesis

Excessive cholesterol contributes to the development of cardiovascular diseases. Berberine (BBR) has been reported to regulate cholesterol homeostasis. Here, we found that BBR could ameliorate the hepatic autophagic flux blockade caused by cholesterol overloading. The underlying mechanism included lowering hepatic cholesterol level, modulating the cholesterol distribution targeting the plasma membrane by decreasing sterol carrier protein 2 expression and inhibiting cyclooxygenase 2-mediated production of prostaglandin metabolites, which decreased the phosphorylation of Akt/mTOR. Our study provides evidences that BBR could be a therapeutic agent for protecting liver under cholesterol overloading via the regulation of autophagic flux.

Disruption of adenosine 2A receptor exacerbates NAFLD through increasing inflammatory responses and SREBP1c activity

Adenosine 2A receptor (A_2A R) exerts protective roles in endotoxin- and/or ischemia-induced tissue damage. However, the role for A_2A R in nonalcoholic fatty liver disease (NAFLD) remains largely unknown. We sought to examine the effects of global and/or myeloid cell-specific A_2A R disruption on the aspects of obesity-associated NAFLD and to elucidate the underlying mechanisms. Global and/or myeloid cell-specific A_2A R-disrupted mice and control mice were fed a high-fat diet (HFD) to induce NAFLD. In addition, bone marrow-derived macrophages and primary mouse hepatocytes were examined for inflammatory and metabolic responses. Upon feeding an HFD, both global A_2A R-disrupted mice and myeloid cell-specific A_2A R-defcient mice revealed increased severity of HFD-induced hepatic steatosis and inflammation compared with their respective control mice. In in vitro experiments, A_2A R-deficient macrophages exhibited increased proinflammatory responses, and enhanced fat deposition of wild-type primary hepatocytes in macrophage-hepatocyte cocultures. In primary hepatocytes, A_2A R deficiency increased the proinflammatory responses and enhanced the effect of palmitate on stimulating fat deposition. Moreover, A_2A R deficiency significantly increased the abundance of sterol regulatory element-binding protein 1c (SREBP1c) in livers of fasted mice and in hepatocytes upon nutrient deprivation. In the absence of A_2A R, SREBP1c transcription activity was significantly increased in mouse hepatocytes.

CONCLUSION

Taken together, our results demonstrate that disruption of A_2A R in both macrophage and hepatocytes accounts for increased severity of NAFLD, likely through increasing inflammation and through elevating lipogenic events due to stimulation of SREBP1c expression and transcription activity. (Hepatology 2018;68:48-61).

Berberine Protects Against Palmitate-Induced Apoptosis in Tubular Epithelial Cells by Promoting Fatty Acid Oxidation

BACKGROUND Increased lipid accumulation in renal tubular epithelial cells (TECs) contributes to their injury and dysfunction and progression of tubulointerstitial fibrosis. Berberine (BBR), a natural plant alkaloid isolated from traditional medicine herbs, is effective in lowing serum lipid, and has a protective effect on chronic kidney disease (CKD) with dyslipidemia, including diabetic nephropathy. The aim of this study was to investigate the effect of BBR on palmitate (PA)-induced lipid accumulation and apoptosis in TECs. MATERIAL AND METHODS Human kidney proximal tubular epithelial cell line (HK-2) cells were treated with PA, BBR, and/or palmitoyltransferase 1A (CPT1A) inhibitor Etomoxir. Intracellular lipid content was assessed by Oil Red O and Nile Red staining. Cell apoptosis rate was evaluated by flow cytometry assay. The expression of apoptosis-related protein cleaved-caspase3 and fatty acid oxidation (FAO)-regulating proteins, including CPT1A, peroxisome proliferator-activated receptor α (PPARα), and PPARγ co-activator-1α (PGC1α), was measured by Western blot analysis and immunofluorescence. RESULTS In the present study, PA treatment increased intracellular lipid deposition accompanied by elevated apoptosis in TECs compared with control group, whereas the protein expression of CPT1A, PPARα, and PGC1α, did not correspondingly increase in TECs. BBR significantly up-regulated the protein expression of CPT1A, PPARα, and PGC1α in TECs treated with or without PA, and reversed PA-induced intracellular lipid accumulation and apoptosis. Moreover, the CPT1A inhibitor Etomoxir counteracted the protective effect of BBR in TECs. CONCLUSIONS These in vitro findings suggest that PA can induce intracellular lipid accumulation and apoptosis in TECs, and the mechanism may be associated with inducing defective FAO, whereas BBR can protect TECs against PA-induced intracellular lipid accumulation and apoptosis by promoting FAO.

Combination of Pelargonium sidoides and Coptis chinensis root inhibits nuclear factor kappa B-mediated inflammatory response in vitro and in vivo

Background

Pelargonium sidoides (PS) and Coptis chinensis root (CR) have traditionally been used to treat various diseases, including respiratory and gastrointestinal infections, dysmenorrhea, and hepatic disorders. The present study was conducted to evaluate the anti-inflammatory effects of a combination of PS and CR in vitro and in vivo.

Methods

The in vitro effects of PS + CR on the induction of inflammation-related proteins were evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The levels of nitric oxide (NO) and of inflammatory cytokines and prostaglandin E₂ (PGE₂) were measured using the Griess reagent and enzyme-linked immunosorbent assay (ELISA) methods, respectively. The expression of inflammation-related proteins was confirmed by Western blot. Additionally, the effects of PS + CR on paw edema volume, skin thickness, and numbers of infiltrated inflammatory cells, mast cells, COX-2-, iNOS-, and TNF-α-immunoreactive cells in dorsum and ventrum pedis skin were evaluated in a rat model of carrageenan (CA)-induced paw edema.

Results

PS + CR significantly reduced production of NO, PGE₂ and three pro-inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6) and also decreased levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Treatment with PS + CR significantly reduced the protein expression levels of LPS-stimulated nuclear factor kappa B (NF-κB) and phosphorylated inhibitor of NF-κB (p-I-κBα). Additionally, PS + CR significantly inhibited the increases in paw swelling, skin thickness, infiltrated inflammatory cells, mast cell degranulation, COX-2-, iNOS-, and TNF-α-immunoreactive cells in the rat model of CA-induced acute edematous paw.

Conclusions

These results demonstrate that PS + CR exhibits anti-inflammatory properties through decreasing the production of pro-inflammatory mediators (NO, PGE₂, TNF-α, IL-1β, and IL-6), suppressing NF-κB signaling in LPS-induced RAW 264.7 cells. Additionally, the results of the CA-induced rat paw edema assay revealed an anti-edema effect of PS + CR. Furthermore, it is suggested that PS + CR also inhibits acute edematous inflammation by suppressing mast cell degranulation and inflammatory mediators (COX-2, iNOS, and TNF-α). Thus, PS + CR may be a potential candidate for the treatment of various inflammatory diseases, and it may also contribute to a better understanding of the molecular mechanisms underlying inflammatory response regulation.

Diet Composition for the Management of Obesity and Obesity-related Disorders

Healthy nutrition is essential for prevention of disease and for maintenance or promotion of health; although healthy nutrition remains to be precisely defined. Over the past several decades, various types of nutrients have been functionally validated and considered as critical components of healthy nutrition, which commonly include fiber-enriched carbohydrates, mono- or poly-unsaturated fatty acids, essential amino acids, and certain micronutrients. When managing obesity and obesity-associated metabolic diseases, much attention has been paid to the content of nutrients that is considered as healthy nutrition. Accumulating evidence also suggests that nutrient composition could be more important than the content of individual nutrients in the context of reducing body weight and obesity-associated risk for metabolic diseases. Consistently, it would be more important to focus on diet with differences in nutrient ratios rather than individual type(s) of nutrients in terms of managing obesity and metabolic diseases. In this review, recent advances in dietary management of obesity and obesity-related metabolic diseases have been discussed. This review also has highlighted several specific diet compositions and their differences in managing hypertension, type 2 diabetes, and non-alcoholic fatty liver disease.

Berberine treatment increases Akkermansia in the gut and improves high-fat diet-induced atherosclerosis in Apoe-/- mice

BACKGROUND AND AIMS

Gut microbiota plays a major role in metabolic disorders. Berberine is used to treat obesity, diabetes and atherosclerosis. The mechanism underlying the role of berberine in modulating metabolic disorders is not fully clear because berberine has poor oral bioavailability. Thus, we evaluated whether the antiatherosclerotic effect of berberine is related to alterations in gut microbial structure and if so, whether specific bacterial taxa contribute to the beneficial effects of berberine.

METHODS

Apoe^-/- mice were fed either a normal-chow diet or a high-fat diet (HFD). Berberine was administered to mice in drinking water (0.5 g/L) for 14 weeks. Gut microbiota profiles were established by high throughput sequencing of the V3-V4 region of the bacterial 16S ribosomal RNA gene. The effects of berberine on metabolic endotoxemia, tissue inflammation and gut barrier integrity were also investigated.

RESULTS

Berberine treatment significantly reduced atherosclerosis in HFD-fed mice. Akkermansia spp. abundance was markedly increased in HFD-fed mice treated with berberine. Moreover, berberine decreased HFD-induced metabolic endotoxemia and lowered arterial and intestinal expression of proinflammatory cytokines and chemokines. Berberine treatment increased intestinal expression of tight junction proteins and the thickness of the colonic mucus layer, which are related to restoration of gut barrier integrity in HFD-fed mice.

CONCLUSIONS

Modulation of gut microbiota, specifically an increase in the abundance of Akkermansia, may contribute to the antiatherosclerotic and metabolic protective effects of berberine, which is poorly absorbed orally. Our findings therefore support the therapeutic value of gut microbiota manipulation in treating atherosclerosis.

Impacts of berberine on oxidized LDL-induced proliferation of human umbilical vein endothelial cells

Berberine (BBR), a Chinese medicine extracted from natural plant, has been demonstrated to improve lipid disorders. Oxidized low-density lipoprotein (oxLDL), a proatherogenic lipoprotein, has been shown to be involved in vascular endothelial cell dysfunction such as excessive or abnormal proliferation. The purpose of the present study was to investigate the impacts of BBR on cell proliferations as well as potential involving signal pathways. HUVECs were stimulated with oxLDL and co-cultured with BBR at a variety of concentrations in different time points. The data showed that oxLDL (10-100 μg/ml) remarkably promoted human umbilical vein endothelial cells (HUVECs) proliferation assessed by Cell Counting Kit-8 (CCK-8) and EdU assay. The effects were found to be involved in up-regulation of proliferating cell nuclear antigen (PCNA), nuclear factor кB (NF-кB) and oxidized low density lipoprotein receptor 1 (LOX-1) and activation of phosphatidylinositol 3 kinase (PI3K)/Akt, ERK1/2 and p38 mitogen-activated protein kinase (MAPK) signaling pathways evaluated by either real time polymerase chain reaction (PCR) or western blot analysis. Interestingly, HUVECs proliferation was significantly inhibited by BBR (5-25 μg/ml), which down-regulated the expression of PCNA, NF-кB and LOX-1 and reduced the phosphorylation of Akt, ERK1/2 and p38MAPK. Furthermore, the anti-proliferative effect of BBR on HUVECs was effectively abrogated by a PI3K inhibitor LY294002, an ERK1/2 inhibitor PD98059 and a p38 inhibitor SB202190 partly through the restoration of phosphorylation of Akt, ERK1/2 and p38MAPK. Taken together, our data suggested that BBR inhibited ox-LDL-induced HUVECs proliferation by decreasing the expression of PCNA, NF-кB and LOX-1 and suppressing the activation of PI3K/Akt, ERK1/2 and p38MAPK pathways, indicating a latent candidate for anti-atherosclerosis clinically.

Cyclic GMP-AMP Ameliorates Diet-induced Metabolic Dysregulation and Regulates Proinflammatory Responses Distinctly from STING Activation

Endogenous cyclic GMP-AMP (cGAMP) binds and activates STING to induce type I interferons. However, whether cGAMP plays any roles in regulating metabolic homeostasis remains unknown. Here we show that exogenous cGAMP ameliorates obesity-associated metabolic dysregulation and uniquely alters proinflammatory responses. In obese mice, treatment with cGAMP significantly decreases diet-induced proinflammatory responses in liver and adipose tissues and ameliorates metabolic dysregulation. Strikingly, cGAMP exerts cell-type-specific anti-inflammatory effects on macrophages, hepatocytes, and adipocytes, which is distinct from the effect of STING activation by DMXAA on enhancing proinflammatory responses. While enhancing insulin-stimulated Akt phosphorylation in hepatocytes and adipocytes, cGAMP weakens the effects of glucagon on stimulating hepatocyte gluconeogenic enzyme expression and glucose output and blunts palmitate-induced hepatocyte fat deposition in an Akt-dependent manner. Taken together, these results suggest an essential role for cGAMP in linking innate immunity and metabolic homeostasis, indicating potential applications of cGAMP in treating obesity-associated inflammatory and metabolic diseases.

Nutritional approaches for managing obesity-associated metabolic diseases

Obesity is an ongoing pandemic and serves as a causal factor of a wide spectrum of metabolic diseases including diabetes, fatty liver disease, and cardiovascular disease. Much evidence has demonstrated that nutrient overload/overnutrition initiates or exacerbates inflammatory responses in tissues/organs involved in the regulation of systemic metabolic homeostasis. This obesity-associated inflammation is usually at a low-grade and viewed as metabolic inflammation. When it exists continuously, inflammation inappropriately alters metabolic pathways and impairs insulin signaling cascades in peripheral tissues/organs such as adipose tissue, the liver and skeletal muscles, resulting in local fat deposition and insulin resistance and systemic metabolic dysregulation. In addition, inflammatory mediators, e.g., proinflammatory cytokines, and excessive nutrients, e.g., glucose and fatty acids, act together to aggravate local insulin resistance and form a vicious cycle to further disturb the local metabolic pathways and exacerbate systemic metabolic dysregulation. Owing to the critical role of nutrient metabolism in controlling the initiation and progression of inflammation and insulin resistance, nutritional approaches have been implicated as effective tools for managing obesity and obesity-associated metabolic diseases. Based on the mounting evidence generated from both basic and clinical research, nutritional approaches are commonly used for suppressing inflammation, improving insulin sensitivity, and/or decreasing fat deposition. Consequently, the combined effects are responsible for improvement of systemic insulin sensitivity and metabolic homeostasis.

Berberine confers neuroprotection in coping with focal cerebral ischemia by targeting inflammatory cytokines

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Berberine reduces brain edema and infarct volume through regulation of inflammatory responses in focal cerebral ischemia.

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Berberine increases the expression of anti-inflammatory cytokines after ischemic stroke.

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Berberine contributes to recovery of motor function after focal cerebral ischemia.

Scope

Existing research indicates that anti-inflammatory and antioxidant properties of berberine play major roles in coping with oxidative stress in neurodegenerative diseases, but it is not known if this isoquinoline alkaloid affects inflammatory cytokines such as interleukin 10 in focal cerebral ischemia.

Methods and results

Male Wistar rats (10 weeks old) were treated with 40 mg/kg concentration of berberine 1 h after focal cerebral ischemia and the anti-inflammatory properties of berberine were evaluated by immunohistochemical analysis, water content measure and behavioral tests. Evaluation of infarct volume was performed by TTC staining. Immunohistochemistry and behavioral assessment indicated recovery in treatment group compared to only ischemia group. The infarct volume decreased in treatment group compared to ischemia group. Berberine administration significantly decreased brain edema and contributed to the restoration of motor function. Moreover, berberine potently contributed to neuroprotection in motor area through downregulation of pro-inflammatory cytokines and upregulation of anti-inflammatory cytokines.

Conclusions

These findings confirm the validity of berberine as a potent anti-inflammatory agent in treatment of ischemic stroke.

Berberine improves glucogenesis and lipid metabolism in nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is considered a critical hepatic manifestation of metabolic syndrome. Berberine (BBR) exerts anti-hyperglycemic and anti-dyslipidemic effects and can also ameliorate NAFLD. Thus, BBR might exert its therapeutic effect on NAFLD by improving glucolipid metabolism. Here, we investigated the aspects and extent to which glucolipid metabolism were affected by BBR in rats with NAFLD.

METHODS

Three groups of Sprague-Dawley rats were studied: a control group (n = 6) fed a normal chow diet and a NAFLD group (n = 6) and a NAFLD + BBR group (n = 6) fed a high-fat diet. Normal saline and BBR (150 mg/kg body weight/day for 16 weeks) were administered by gavage. All rats were infused with isotope tracers. The rates of glucose appearance (Ra_glu), gluconeogenesis (GNG) and glycerol appearance (Ra_gly) were assessed with ²H and ¹³C tracers, whereas the rates of hepatic lipogenesis and fatty acid β oxidation were measured using the ³H tracer.

RESULTS

When the NAFLD model was successfully induced by administering a high-fat diet, body weight, insulin resistance and dyslipidemia were significantly increased. After the BBR treatment, weight loss, decreased lipid profiles and HOMA-IR, and increased ISI were observed. Meanwhile, BBR reduced Ra_glu, GNG and hepatic lipogenesis, whereas the rate of fatty acid β oxidation in skeletal muscle showed an increasing trend. Ra_gly showed a decreasing trend. Based on the results of the histological analysis, BBR obviously attenuated the ectopic liver fat accumulation.

CONCLUSIONS

BBR improved NAFLD by inhibiting glucogenesis and comprehensively regulating lipid metabolism, and its effect on inhibiting hepatic lipogenesis was much stronger. The improvement may be partly mediated by weight loss. Berberine might be a good choice for patients with NAFLD and glucose metabolic disorder. Future clinical trials need to be conducted to confirm these effects.

Orally Administered Berberine Modulates Hepatic Lipid Metabolism by Altering Microbial Bile Acid Metabolism and the Intestinal FXR Signaling Pathway

Previous studies suggest that the lipid-lowering effect of berberine (BBR) involves actions on the low-density lipoprotein receptor and the AMP-activated protein kinase signaling pathways. However, the implication of these mechanisms is unclear because of the low bioavailability of BBR. Because the main action site of BBR is the gut and intestinal farnesoid X receptor (FXR) plays a pivotal role in the regulation of lipid metabolism, we hypothesized that the effects of BBR on intestinal FXR signaling pathway might account for its pharmacological effectiveness. Using wild type (WT) and intestine-specific FXR knockout (FXR^int-/-) mice, we found that BBR prevented the development of high-fat-diet-induced obesity and ameliorated triglyceride accumulation in livers of WT, but not FXR^int-/- mice. BBR increased conjugated bile acids in serum and their excretion in feces. Furthermore, BBR inhibited bile salt hydrolase (BSH) activity in gut microbiota, and significantly increased the levels of tauro-conjugated bile acids, especially tauro-cholic acid(TCA), in the intestine. Both BBR and TCA treatment activated the intestinal FXR pathway and reduced the expression of fatty-acid translocase Cd36 in the liver. These results indicate that BBR may exert its lipid-lowering effect primarily in the gut by modulating the turnover of bile acids and subsequently the ileal FXR signaling pathway. In summary, we provide the first evidence to suggest a new mechanism of BBR action in the intestine that involves, sequentially, inhibiting BSH, elevating TCA, and activating FXR, which lead to the suppression of hepatic expression of Cd36 that results in reduced uptake of long-chain fatty acids in the liver.

ERK-dependent mTOR pathway is involved in berberine-induced autophagy in hepatic steatosis

Non-alcoholic fatty liver disease (NAFLD) is a burgeoning health problem and is considered as a hepatic manifestation of metabolic syndrome. Increasing evidence demonstrates that berberine (BBR), a natural plant alkaloid, is beneficial for obesity-associated NAFLD. However, the mechanisms about how BBR improves hepatic steatosis remain uncertain. Recently, some reports revealed that enhanced autophagy could decrease hepatic lipid accumulation. In this study, we first established a high-fed diet (HFD) mice model and oleate-palmitate-induced lipotoxicity hepatocytes to explore the association among BBR, autophagy and hepatic steatosis. Our data demonstrated that BBR had profound effects on improving hepatic lipid accumulation both in vivo and in vitro, and led to high autophagy flux. The molecular alterations proceeding these changes were characterized by inhibition of the ERK/mTOR pathway. These findings suggest an important mechanism for the positive effects of BBR on hepatic steatosis, and may provide new evidence for the clinical use of BBR in NAFLD.

The Potential Mechanisms of Berberine in the Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a globally observed metabolic disease with high prevalence both in adults and children. However, there is no efficient medication available yet. Increased evidence indicates that berberine (BBR), a natural plant product, has beneficial effects on NAFLD, though the mechanisms are not completely known. In this review, we briefly summarize the pathogenesis of NAFLD and factors that influence the progression of NAFLD, and focus on the potential mechanisms of BBR in the treatment of NAFLD. Increase of insulin sensitivity, regulation of adenosine monophosphate-activated protein kinase (AMPK) pathway, improvement of mitochondrial function, alleviation of oxidative stress, LDLR mRNA stabilization, and regulation of gut microenvironment are the major targets of BBR in the treatment of NAFLD. Additionally, reduction of proprotein convertase subtilisin/kexin 9 (PCSK9) expression and DNA methylation are also involved in pharmacological mechanisms of berberine in the treatment of NAFLD. The immunologic mechanism of BBR in the treatment of NAFLD, development of berberine derivative, drug combinations, delivery routes, and drug dose can be considered in the future research.

Rhizoma Coptidis: A Potential Cardiovascular Protective Agent

Cardiovascular diseases (CVDs) are among the leading causes of morbidity and mortality in both the developed and developing world. Rhizoma coptidis (RC), known as Huang Lian in China, is the dried rhizome of medicinal plants from the family Ranunculaceae, such as Coptis chinensis Franch, C. deltoidea C.Y. Cheng et Hsiao, and C. teeta Wall which has been used by Chinese medicinal physicians for more than 2000 years. In China, RC is a common component in traditional medicines used to treat CVD associated problems including obesity, diabetes mellitus, hyperlipidemia, hyperglycemia and disorders of lipid metabolism. In recent years, numerous scientific studies have sought to investigate the biological properties of RC to provide scientific evidence for its traditional medical uses. RC has been found to exert significant beneficial effects on major risk factors for CVDs including anti-atherosclerotic effect, lipid-lowering effect, anti-obesity effect and anti-hepatic steatosis effect. It also has myocardioprotective effect as it provides protection from myocardial ischemia-reperfusion injury. These properties have been attributed to the presence of bioactive compounds contained in RC such as berberine, coptisine, palmatine, epiberberine, jatrorrhizine, and magnoflorine; all of which have been demonstrated to have cardioprotective effects on the various parameters contributing to the occurrence of CVD through a variety of pathways. The evidence available in the published literature indicates that RC is a herb with tremendous potential to reduce the risks of CVDs, and this review aims to summarize the cardioprotective properties of RC with reference to the published literature which overall indicates that RC is a herb with remarkable potential to reduce the risks and damage caused by CVDs.

The Therapeutic Effect of Berberine in the Treatment of Nonalcoholic Fatty Liver Disease: A Meta-Analysis

Aim. To assess the efficacy of berberine in the treatment of nonalcoholic fatty liver disease through meta-analysis. Method. We searched Embase, Pubmed, Cochrane Library, and so forth, until March 2016 for randomized controlled trials using berberine to treat NAFLD. Result. Six randomized controlled trials involving 501 patients were included in this study. The results showed that the efficacy of reducing TC, LDL, ALT, 2hPG, and HbA1c in NAFLD patients of the berberine group were significantly higher than that of control group. The subgroup analyses on TG, AST, and FBG indicated that treatment combined with berberine decreased TG level in NAFLD patients significantly. Compared with other drugs, berberine alone decreased TG level in NAFLD patients significantly. We also conducted a descriptive analysis on insulin resistance and radiography results that berberine can improve NAFLD patients' insulin resistance and fatty liver. Conclusion. According to analysis result, berberine has positive efficacy on blood lipids, blood glucose, liver function, insulin resistance, and fatty liver condition of NAFLD patients. However, due to the limitation of number and quality of trials included, more clinical randomized controlled trials with high quality are needed for further verification of the efficacy of berberine on NAFLD patients.

New insights into salvianolic acid A action: Regulation of the TXNIP/NLRP3 and TXNIP/ChREBP pathways ameliorates HFD-induced NAFLD in rats

Salvianolic acid A (SalA), one of the most efficacious polyphenol compounds extracted from Radix Salvia miltiorrhiza (Danshen), has been shown to possess many potential pharmacological activities. This study aimed to investigate whether SalA has hepatoprotective effects against high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) and to further explore the mechanism underlying this process. SalA treatment significantly attenuated HFD-induced obesity and liver injury, and markedly decreased lipid accumulation in HFD-fed rat livers. Moreover, SalA treatment ameliorated HFD-induced hepatic inflammation and oxidative stress by decreasing hepatotoxic levels of cytokines, suppressing the overproduction of reactive oxygen species (ROS) and methane dicarboxylic aldehyde (MDA) and preventing the decreased expression of superoxide dismutase (SOD). Importantly, SalA reversed the HFD- or palmitic acid (PA)-induced activation of the NLRP3 inflammasome, the nuclear translocation of ChREBP and the up-regulation of FAS, and these effects were accompanied by TXNIP down-regulation. However, TXNIP siRNA treatment partially abrogated the above-mentioned effects of SalA in PA-treated HepG2 cells. Together, our results demonstrated, for the first time, that SalA protects against HFD-induced NAFLD by ameliorating hepatic lipid accumulation and inflammation, and these protective effects may partially due to regulation of the TXNIP/NLRP3 and TXNIP/ChREBP pathways.