Mechanistic insights into the amelioration effects of diabetic cardiomyopathy by berberine:an integrated systems pharmacology study and experimental validation

Background:Diabetic cardiomyopathy(DCM)is a type of cardiomyopathy caused by long-term diabetes,characterized by abnormal myocardial structure and function,which can lead to heart failure.Berberine(BBR),a quaternary ammonium alkaloid isolated from Coptidis Rhizoma,a traditional Chinese medicine,has superior anti-diabetic and heart-protective properties.The purpose of this study is to assess the impact of BBR on DCM.Methods:This study used a systems pharmacology approach to evaluate the related proteins and signalling pathways between BBR and DCM targets,combined with experimental validation using diabetic mouse heart sections.Microstructural and pathological changes were observed using Hematoxylin-eosin,Masson’s trichrome stain and wheat germ agglutinin staining.Immunofluorescence and western blot were used to determine protein expression.Results:The results indicate that BBR and DCM share 21 core relevant targets,with cross-targets predominantly located in mitochondrial,endoplasmic reticulum,and plasma membrane components.BBR exerts its main effects in improving DCM by maintaining mitochondrial integrity,particularly involving the PI3K-AKT-GSK3βand apoptosis signalling pathways.In addition,post-treatment changes in the key targets of BBR,including cysteine aspartate specific protease(Caspase)-3,phosphoinositide 3-kinase(PI3K)and mitochondria-related proteins,are suggestive of its efficacy.Conclusion:BBR crucially improves DCM by maintaining mitochondrial integrity,inhibiting apoptosis,and modulating PI3K-AKT-GSK3βsignaling.Further studies must address animal model limitations and validate clinical efficacy to understand BBR’s mechanisms fully and its potential clinical use.

Network pharmacology and computational analysis of berberine and kuwanon Z as possible natural antiviral compounds in COVID-19

Background:Global efforts to discover effective therapeutic agents for combating coronavirus disease 19(COVID-19)have intensified the exploration of natural compounds with potential antiviral properties.In this study,we utilized network pharmacology and computational analysis to investigate the antiviral effects of Berberine and Kuwanon Z against severe acute respiratory syndrome coronavirus 2,the viruses responsible for COVID-19.Method:Utilizing comprehensive network pharmacology approaches,we elucidated the complex interactions between these compounds and the host biological system,highlighting their multitarget mechanisms.Network pharmacology identifies COVID-19 targets and compounds through integrated protein‒protein interaction and KEGG pathway analyses.Molecular docking simulation studies were performed to assess the binding affinities and structural interactions of Berberine and Kuwanon Z with key viral proteins,shedding light on their potential inhibitory effects on viral replication and entry.Results:Network-based analyses revealed the modulation of crucial pathways involved in the host antiviral response.Compound-target network analysis revealed complex interactions(122 nodes,121 edges),with significant interactions and an average node degree of 1.37.KEGG analysis revealed pathways such as the COVID-19 pathway,chemokines and Jak-sat in COVID-19.Docking studies revealed that Kuwanon Z had binding energies of-10.5 kcal/mol for JAK2 and-8.1 kcal/mol for the main protease.Conclusion:The findings of this study contribute to the understanding of the pharmacological actions of Berberine and Kuwanon Z in the context of COVID-19,providing a basis for further experimental validation.These natural compounds exhibit promise as potential antiviral agents,offering a foundation for the development of novel therapeutic strategies in the ongoing battle against the global pandemic.

Protective Effects of Berberine on Nonalcoholic Fatty Liver Disease in db/db Mice via AMPK/SIRT1 Pathway Activation

Objective Berberine(BBR)has emerged as a promising therapeutic agent for nonalcoholic fatty liver disease(NAFLD).This study aims to elucidate the underlying molecular mechanisms.Methods In this study,db/db mice were chosen as an animal model for NAFLD.A total of 10 healthy C57BL/6J mice and 30 db/db mice were randomly allocated to one of 4 groups:the normal control(NC)group,the diabetic control(DC)group,the Metformin(MET)therapy group,and the BBR therapy group.The total cholesterol(TC),triacylglycerol(TG),low-density lipoprotein cholesterol(LDL-c),high-density lipoprotein cholesterol(HDL-c),aspartate aminotransferase(AST)and alanine aminotransferase(ALT)levels in the serum were measured.The glutathione peroxidase(GSH-Px),glutathione(GSH),malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT),interleukin(IL)-1β,tumor necrosis factor(TNF)-αand monocyte chemotactic protein 1(MCP-1)levels in liver tissue were measured.Hematoxylin and eosin(H&E),acid-Schiff(PAS)and TUNEL stanning was performed for histopathological analysis.Western blotting and immunohistochemistry were conducted to detect the expression levels of key proteins in the AMPK/SIRT1 pathway.Results BBR could improve lipid metabolism,attenuate hepatic steatosis and alleviate liver injury significantly.The excessive oxidative stress,high levels of inflammation and abnormal apoptosis in db/db mice were reversed after BBR intervention.BBR clearly changed the expression of AMP-activated protein kinase(AMPK)/Sirtuin 1(SIRT1),and their downstream proteins.Conclusion BBR could reverse NAFLD-related liver injury,likely by activating the AMPK/SIRT1 signaling pathway to inhibit oxidative stress,inflammation and apoptosis in hepatic tissue.

Therapeutic Potential of Berberine in Type 2 Diabetes: A Short Review

Background: Type 2 Diabetes Mellitus (T2DM) is a multifactorial disease that is influenced by genetic, metabolic, and environmental factors. Genetic predisposition, obesity, low physical activity, and unhealthy diet are key risk factors for T2DM. Result: Type 2 diabetes is treated with various natural medicines, the most significant of which is berberine (BBR). Berberine, an isoquinoline alkaloid found in various medicinal plants, exhibits a wide range of pharmacological activities and (BBR) has the potential to treat various diseases, such as diabetes, cancer, and metabolic and cardiovascular diseases. Conclusion: It has been found to be effective in AMPK activation, regulation of blood glucose and lipids, stimulation of insulin secretion from pancreatic beta cells, inhibition of cancer cells, and reduction of fat formation.

Network pharmacology and bioinformatics analysis identify potential therapeutic effects of berberine on colon cancer complicated with radiation enteritis

Objective:Patients with colon adenocarcinoma(COAD)who undergo radiation therapy develop radiation enteritis(RE).The predictive value of RE in COAD is yet to be established.Berberine,an active compound derived from the traditional Chinese medicinal plant,Coptis chinensis,has notable anti-inflammatory properties and offers protection to the intestinal mucosa.This study aimed to evaluate the possible therapeutic effect and mechanism of berberine as a treatment for COAD complicated with RE(COAD&RE).Methods:Relevant genetic features of diverse COAD&RE populations were analyzed using bioinformatics and the Cox proportional hazards regression model.The therapeutic targets of berberine were predicted using network pharmacology and molecular docking.In vivo and in vitro experiments were conducted to validate the core genes identified using molecular docking.Results:RE has a certain impact on the prognosis of COAD and berberine may play an important role in the treatment of COAD&RE.In addition,we identified five core therapeutic targets of berberine by network pharmacology and molecular docking:CCND1,MYC,AR,LEP,and CYP19A1.In vivo experiments showed that berberine increased short-term survival rate,body weight,and intestinal epithelial cell recovery in mice after radiation.In an in vitro study,berberine promoted the proliferation of human intestinal epithelial cells and enhanced the radiosensitivity of HT29 cells after radiation,and the relative mRNA expression levels of CCND1 and MYC closely correlated with these effects.Conclusions:This study predicted the potential therapeutic effects of berberine on COAD&RE and verified the relevant mechanisms,which may provide insights and suggestions for the clinical treatment of COAD&RE.

小檗碱通过Ezrin蛋白抑制鼻咽癌细胞迁移和伪足形成

目的观察小檗碱（Berberine，BBR）对鼻咽癌细胞埃兹蛋白（Ezrin）和磷酸化埃兹蛋白（phos-Ezrin）表达的影响以及其对细胞伪足形成和迁移的抑制作用，探讨BBR抗鼻咽癌转移可能的分子机制。方法以体外培养的鼻咽癌细胞株（CNE1）为研究对象，用MTr法分析BBR对CNE1细胞生长的影响，选用BBR细胞无毒性浓度（non-cytotoxic concentration，NCC）进行实验。免疫印迹（Western-blotting）分析CNE1Ezrin和phos-Ezrin的表达。用光镜CNE1观察细胞迁移能力，电子显微镜观察细胞伪足形成。Ezrin小干扰RNA（Ezrin-siRNA）转染阻断Ezrin蛋白表达，进一步确证BBR通过Ezrin抑制细胞伪足形成。结果MTT结果显示，BBR在5μM以上明显抑制CNE1增殖（P〈0．05），浓度（0—5）州对CNE1细胞生长增殖抑制作用不明显，为BBR对CNE1的细胞无毒性浓度（NCC）。BBR在NCC能明显抑制CNE1细胞phos-Ezfin表达，且呈浓度依赖性。光镜观察显示BBR对CNE1细胞迁移有明显的抑制作用。电镜观察结果显示，BBR抑制CNE1细胞伪足形成。结论BBR可能通过抑制Ezfin磷酸化而抑制鼻咽癌CNE1迁移。

Simultaneous Determination of Baicalin, Berberine and Rhein by HPLC in Traditional Chinese Patent Medicine Sanhuang Tablets

Aim To establish a reversed phase liquid chromatographic method forsimultaneous determination of three main medicinal constituents, baicalin, berberine and rhein, inSanhuang tablets. Methods The separation was performed on a Kromasil C_(18) column with TEA-adjusted0.02 mol·L^(-1) H_3PO_4 (pH 6.78)-acetonitrile-methanol (40 : 9 : 7) as mobile phase at aflow-rate of 1.0 mL·min^(-1), with detection at 254 ran. Considering interaction between acidic andalkaline compounds, three standard markers were added respectively and the volume of samplesolution was doubled in recovery experiments. Results Three regression equations revealed excellentlinear relationship between the peak areas and concentrations and the correlation coefficients allsurpassed 0.999 8. The average recovery was 96.1% (RSD = 2.1%) baicalin, 98.5% (RSD = 2.4%) forberberine, and 101.5% (RSD =1.3%) for rhein. Conclusion The method developed can be used to controlthe quality of Sanhuang tablets comprehensively.

Effect of Berberine Chloride on Experimental Murine Colitis Induced by Dextran Sulfate Sodium

Aim To investigate the effect in berberine chloride （BER） on experimental ulcerative colitis in mice. Methods BALB/C mice in 6 groups were allowed to drink either 4% dextran sulfate sodium （DSS） solution or distilled water freely with different doses of BER （15 mg·kg^-1, 45 mg·kg^-1, 150 mg·kg^-1） or sallcylazosulfapyridine （SASP, 520 mg·kg^-1）, and solvent （0. 2 mL/10 mg Wt） once a day for 7 d, respectively. The symptom of ulcerative colitis was evaluated by disease activity index （DAI）. Myeloperoxidase （MPO） and superoxide dismutase （SOD） activities and malondialdehyde （MDA） content were determined by HE staining and immunohistochemistry of expressions of NF-κB p65 and intercellular adhesion molecule 1 （ ICAM-1 ） proteins to observe the damage to colon tissues and possible mechanisms. Results DAI, MPO activity, MDA content and expressions of ICAM-1 and NF-κB p65 were markedly increased, while SOD activity decreased in DSS-treated mice. Treatment of mice with different doses of BER or SASP significantly decreased DAI, MPO activity and MDA content, improved histological changes of colon tissues, blunted the expressions of NF-κB p65 and ICAM-1 proteins, and enhanced SOD activity. Conclusion Berberine chloride has excellent therapeutic effect on ulcerative colitis caused by DSS in mice. The possible mechanism may be related to its antioxidant and anti-inflammatory activities associated with inhibiting the NF-κB activation and ICAM-1 expression.

小檗碱和溴化乙锭与DNA的光谱学作用研究

利用荧光光谱、紫外-可见吸收光谱、圆二色谱、琼脂糖凝胶电泳方法研究了小檗碱(berberine)和溴化乙锭(EB)与ct-DNA的光谱学作用.在ct-DNA存在时,berberine和EB的荧光强度都有较大的提高,pH的改变对二者荧光光谱的发射峰位与强度影响不大;紫外-可见吸收光谱随ct-DNA浓度的增加,表现出减色效应;二者都使ct-DNA的圆二色谱正负峰的吸收强度有所增加;琼脂糖凝胶电泳实验表明,EB-DNA体系的发光强度高于berberine-DNA体系.在DNA的定量测定中,可用无毒、副作用的小檗碱代替有致癌性的溴化乙锭,为安全、无环境污染、定量测定DNA提供了新试剂使用基础.

Effect of berberine on glucolipid metabolization in diabetic skeletal muscle and its mechanism

Aim To investigate the effect of berberine on damaged morphology and glucolipid metabolization in skeletal muscle of diabetic rat and the relationship between peroxisome proliferator-activated receptor （PPARs） α/γ/δ protein expression. Methods Type 2 diabetes mellitus rats were induced by an injection of 35 mg.kg^-1 streptozotocin （STZ） and a high-carbohydrate/ high-fat diet for 16 weeks. From week 17 to 32, diabetic rats were given low-, middle-, high-dose berberine （75, 150, 300 mg.kg^-1）, fenofibrate （100 mg.kg^-1） and rosiglitazone （4 mg.kg^-1） by oral administration, respectively. The skeletal muscle structure was observed with hematoxylin-eosin （HE） staining, glycogen and triglyceride contents were measured by spectrophotometry and PPAR α/γ/δ protein expressions were detected by immunohistochemistry. Results Fiber distribution remained normal in skeletal muscles of all the groups, middle-, high-dose berberine partly improved diabetic fibre atrophy, increased glycogen and decreased triglyceride levels in diabetic muscle （P〈 0.01）. Middle-, high-dose berberine and rosiglitazone all significantly reduced PPARy protein level in diabetic skeletal muscle （P 〈 0.01）; middle-, high-dose berberine and fenofibrate strikingly increased both PPARu and PPAR8 expression （P〈 0.01）. Conclusion Berberine modulates PPAR α/γ/δ protein expression in diabetic skeletal muscle which may contribute to ameliorate fibre damage and glucolipid metabolization.

Effects of Berberine on TXB 2 and 6 Keto PGF 1α Plasma Levels in Rabbits with Uncomplete Cerebral Ischemia

Effects of berberine (Ber) on platelet aggregation and TXB2 and 6 keto PGF1a plasma levels were studied in rabbits with uncomplete cerebral ischemia. Ber inhibited uncomplete cerebral ischemic rabbit platelet aggregation triggered by collagen, ADP, and arachidonic acid (AA) with the IC 50 of 0.15, 0.46, and 0.51 mg·ml 1 , respectively. In rabbits, Ber 25, or 50 mg·kg 1 iv 30 min after uncomplete cerebral ischemia, restrained the collagen ADP and AA induced platelet aggregation determined 90 min later. With radioimmunoassay, we measured the thromboxane B2 (TXB 2) and 6 ketoprostaglandin F 1α (6 keto PGF 1α ) contents in rabbit plasma. The results indicated that the TXB 2 level in rabbit 120 min after uncomplete cerebral ischemia (921±539 pg·ml 1 ) was higher than that (230±71 pg·ml 1 ) in normal rabbits ( P < 0.01), but 6 keto PGF 1α level after ischemia (73±23pg·ml 1 ) was lower than that (262±988pg·ml 1 ) in normal rabbit. Ber (5, 25 or 50 mg·kg 1 ) reduced obviously the plasma TXB 2 level in rabbit with uncomplete cerebral ischemia (504±196, 386±174, or 272±183 vs 921±539 pg·ml 1 , respectively, P < 0.01). We conclude that the decrease of TXB 2 content is one of the possible mechanisms of Ber anti cerebral ischemic effect.

黄连药理与临床研究进展

黄连(Coptis Chinensis Franch)为毛茛科黄连属植物的干燥根茎,具有清热燥湿、泻火解毒功效.其主要成分小蘖碱(berberine,又名黄连素)在治疗肠道疾病中举足轻重。近年来对黄连及黄连素的研究取得不少进展,尤其在心血管方面有了新的认识。本文对黄连和黄连素的药理作用,临床应用及不良反应综述如下。药理作用1.抗病原微生物(1)抗菌:黄连和黄连素是一种广谱抗菌药物,对多种革兰氏阳性菌和阴性菌都有显著抑制效果。体外实验对痢疾杆菌、炭疽杆菌、金黄色葡萄球菌,血溶性链球菌等有较强抗菌作用。

Berberine induces cell cycle arrest and apoptosis in human gastric carcinoma SNU-5 cell line

AIM： To investigate the relationship between the inhibited growth （cytotoxic activity） of berberine and apoptotic pathway with its molecular mechanism of action. METHODS： The in vitro cytotoxic techniques were complemented by cell cycle analysis and determination of sub-G1 for apoptosis in human gastric carcinoma SNU-5 cells. Percentage of viable cells, cell cycle, and sub431 group （apoptosis） were examined and determined by the flow cytometric methods. The associated proteins for cell cycle arrest and apoptosis were examined by Western blotting. RESULTS： For SNU-5 cell line, the IC （50） was found to be 48 μmol/L of berberine. In SNU-5 cells treated with 25-200 μmol/L berberine, G2/M cell cycle arrest was observed which was associated with a marked increment of the expression of p53, Wee1 and CDk1 proteins and decreased cyclin B. A concentration-dependent decrease of cells in G0/G1 phase and an increase in G2/M phase were detected. In addition, apoptosis detected as sub-Go cell population in cell cycle measurement was proved in 25-200 μmol/L berberine-treated cells by monitoring the apoptotic pathway. Apoptosis was identified by sub-Go cell population, and upregulation of Bax, downregulation of Bcl-2, release of Ca^2＋, decreased the mitochondrial membrane potential and then led to the release of mitochondrial cytochrome C into the cytoplasm and caused the activation of caspase-3, and finally led to the occurrence of apoptosis. CONCLUSION： Berberine induces p53 expression and leads to the decrease of the mitochondrial membrane potential, Cytochrome C release and activation of caspase-3 for the induction of apoptosis.

Berberine inhibits hepatic gluconeogenesis via the LKB1-AMPK-TORC2 signaling pathway in streptozotocin-induced diabetic rats

AIM: To investigate the molecular mechanisms of berberine inhibition of hepatic gluconeogenesis in a diabetic rat model.METHODS: The 40 rats were randomly divided into five groups. One group was selected as the normal group. In the remaining groups(n = 8 each), the rats were fed on a high-fat diet for 1 mo and received intravenous injection of streptozotocin for induction of the diabetic models. Berberine(156 mg/kg per day)(berberine group) or metformin(184 mg/kg per day)(metformin group) was intragastrically administered to the diabetic rats and 5-aminoimidazole-4-carboxamide1-β-D-ribofuranoside(AICAR)(0.5 mg/kg per day)(AICAR group) was subcutaneously injected to the diabetic rats for 12 wk. The remaining eight diabetic rats served as the model group. Fasting plasma glucose and insulin levels as well as lipid profile were tested.The expressions of proteins were examined by western blotting. The nuclear translocation of CREB-regulated transcription co-activator(TORC)2 was observed by immunohistochemical staining. RESULTS: Berberine improved impaired glucose tolerance and decreased plasma hyperlipidemia. Moreover, berberine decreased fasting plasma insulin and homeostasis model assessment of insulin resistance(HOMA-IR). Berberine upregulated protein expression of liver kinase(LK)B1, AMP-activated protein kinase(AMPK) and phosphorylated AMPK(p-AMPK). The level of phophorylated TORC2(p-TORC2) protein in the cytoplasm was higher in the berberine group than in the model group, and no significant difference in total TORC2 protein level was observed. Immunohistochemical staining revealed that more TORC2 was localized in the cytoplasm of the berberine group than in the model group. Moreover, berberine treatment downregulated protein expression of the key gluconeogenic enzymes(phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) in the liver tissues. CONCLUSION: Our findings revealed that berberine inhibited hepatic gluconeogenesis via the regulation of the LKB1-AMPK-TORC2 signaling pathway.

Berberine Ameliorates High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease in Rats via Activation of SIRT3/AMPK/ACC Pathway

This study aimed to verify the effects of berberine(BBR)on the fat metabolism proteins involved in the sirtuin 3(SIRT3)/adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)/acetyl-CoA carboxylase(ACC)pathway in the liver tissues of rats with high-fat diet(HFD)-induced non-alcoholic fatty liver disease(NAFLD).Forty-eight rats were randomly divided into the normal control(NC)group,HFD group or BBR group,with 16 rats in each group.After 8 and 16 weeks of treatment,serum and liver samples were collected.Subsequently,body parameters,biochemical parameters and liver pathology were examined.The expression levels of proteins involved in the SIRT3/AMPK/ACC pathway in the liver were detected by Western blotting.After 8 and 16 weeks of a HFD,the successful establishment of rat models with different degrees of NAFLD was confirmed by hematoxylin and eosin(H&E)and Oil Red O staining.NAFLD rat models exhibited obesity and hyperlipidemia,and the protein expression levels of SIRT3,p-AMPK.p-ACC,and CPT-1A in the liver were significantly decreased compared to those in the NC group.The concurrent administration of BBR with the HFD effectively improved serum and liver lipid profiles and ameliorated liver injury.Furthermore,the protein expression levels of SIRT3,p-AMPK,p-ACC,and CPT-1 A in the liver were significantly increased in the BBR group as compared with those in the HFD group.In conclusion,our data suggest that the mechanism by which BBR ameliorates HFD-induced hepatic steatosis may be related to the activation of the SIRT3/AMPK/ACC pathway in the liver.

Berberine reverses free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ

AIM: To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-L1 adipocytes. METHODS: The model of insulin resistance in 3T3-L1 adipocytes was established by adding palmic acid (0.5 mmol/L) to the culture medium. Berberine treatment was performed at the same time. Glucose uptake rate was determined by the 2-deoxy-[3H]-D-glucose method. The levels of IkB kinase beta (IKKβ) Ser181 phosphorylation, insulin receptor substrate-1(IRS-1) Ser307 phosphorylation, expression of IKKβ, IRS-1, nuclear transcription factor kappaB p65 (NF-κB p65), phosphatidylinositol-3-kinase p85 (PI-3K p85) and glucose transporter 4 (GLUT4) proteins were detected by Western blotting. The distribution of NF-κB p65 proteins inside the adipocytes was observed through confocal laser scanning microscopy (CLSM). RESULTS: After the intervention of palmic acid for 24 h, the insulin-stimulated glucose transport in 3T3-L1 adipocytes was inhibited by 67%. Meanwhile, the expression of IRS-1 and PI-3K p85 protein was reduced, while the levels of IKKβ Ser181 and IRS-1 Ser307 phosphorylation, and nuclear translocation of NF-κB p65 protein were increased. However, the above indexes, which indicated the existence of insulin resistance, were reversed by berberine although the expression of GLUT4, IKKβ and total NF-κB p65 protein were not changed during this study. CONCLUSION: Insulin resistance induced by FFAs in 3T3-L1 adipocytes can be improved by berberine. Berberine reversed free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ.

Berberine promotes the development of atherosclerosis and foam cell formation by inducing scavenger receptor A expression in macrophage

Berberine is identified to lower the serum cholesterol level in human and hamster through the induction of low density lipoproteins （LDL） receptor in hepatic cells. To evaluate its potential in preventing atherosclerosis, the effect of berberine on atherosclerosis development in apolipoprotcin E-deficient （apoE^-/-） mice was investigated. In apoE^-/- mice, berberine induced in rivo foam cell formation and promoted atheroselerosis development. The foam cell formation induced by berberinc was also observed in mouse RAW264.7 cells, as well as in mouse and human primary macrophages. By inducing scavenger receptor A （SR-A） expression in macrophages, berberine increased the uptake of modified LDL （DiO-Ac-LDL）. Bcrberine-induced SR-A expression was also observed in macrophage foam cells in vivo and in the cells at atherosclerotic lesion. Analysis in RAW264.7 cells indicated that berberine induced SR-A expression by suppressing PTEN expression, which led to sustained Akt activation. Our results suggest that to evaluate the potential of a cholesterol-reducing compound in alleviating atherosclerosis, its effect on the ceils involved in atherosclerosis development, such as macrophages, should also be considered. Promotion of foam cell formation could counter-balance the beneficial effect of lowering serum cholesterol.

Facilitating effects of berberine on rat pancreatic islets through modulating hepatic nuclear factor 4 alpha expression and glucokinase activity

AIM： To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS： Pdmary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations （1, 3, 10 and 30 μmol/L） of berberine or 1 μmol/L Glibenclamide （GB） for 24 h. Glucose-stimulated insulin secretion （GSIS） assay was conducted and insulin was determined by radioimmunoassay. 3-（4,5-Dimethylthiazol-2-yl）- 2,5-diphenyltetrazolium bromide （MTT） assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha （HAIF4α） was determined by reverse transcription polymerase chain reaction （RT-PCR）. Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase （GK） activity was measured by spectrophotometric method. RESULTS： Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner, and GK activity was also increased accordingly. However, GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION： Berberine can enhance GSIS in rat islets, and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK, which is distinct from sulphonylureas （SUs）.

Antinociceptive effect of berberine on visceral hypersensitivity in rats

AIM: To assess the protective effect of berberine administration and the role of nitric oxide (NO) in visceral hypersensitivity. METHODS: Fifty male Sprague-Dawley rats were randomly assigned to five groups. An inflammatory bowel disease model was induced in rats by intracolonic instillation of 1 mL 4% acetic acid at 8 cm proximal to the anus for 30 s and restraint stress. After subsidence of inflammation on day 7 of the experiment, the rats were subjected to rectal distension, performed by a balloon (6-Fr, 2 mm external diameter, disposable silicon balloon-urethral catheter for pediatric use) which was rapidly inflated with increasing volumes of prewarmed (37 ℃) water (0.1, 0.2, 0.3, 0.4, 0.6, 0.8 and 1 mL) for 30 s at four-minute intervals, and then the abdominal withdrawal reflex (AWR) and the level of fecal output were measured, respectively. AWR scores either 0, 1, 2, 3 or 4 were obtained by blinded observers. Rats had been pretreated with berberine or aminoguanidine (NO synthetase inhibitor) or berberine + aminoguanidine before measurement. RESULTS: The rats in the placebo group showed a hypersensitive response to rectal distension (2.69 ± 0.08 vs 1.52 ± 0.08, P = 0.000) and defecated more frequently than those in the control group (5.0 ± 0.16 vs 0.44 ± 0.16, P = 0.000). Comparing the berberine with placebo group, the AWR scores were reduced for all distension volumes and were significant at 0.2-1 mL (1.90 ± 0.08 vs 2.69 ± 0.08, P = 0.000), while the numbers of hard pellets, soft pellets, formless stools, and total fecal output in the placebo group were significantly larger than in the berberine group (5.0 ± 0.16 vs 2.56 ± 0.16, P = 0.000). Administration of aminoguanidine or berberine + aminoguanidine before VH score measurement reversed the antinociceptive effect of berberine (2.52 ± 0.08 vs 1.90 ± 0.08, P = 0.000; 2.50 ± 0.08 vs 1.90 ± 0.08, P = 0.000). The numbers of hard pellets, soft pellets, formless stool, and total of fecal output in aminoguanidine group were significantly larger than the corresponding values in control group, berberine group, and berberine + aminoguanidine group (4.81 ± 0.16 vs 0.44 ± 0.16, P = 0.000; 4.81 ± 0.16 vs 2.56 ± 0.16, P = 0.000; 4.81 ± 0.16 vs 3.75 ± 0.16, P = 0.000). The berberine and berberine + aminoguanidine groups showed reduced defecation, but aminoguanidine alone did not reduce defecation (2.56 ± 0.16 vs 4.81 ± 0.16, P = 0.000; 3.75 ± 0.16 vs 4.81 ± 0.16, P = 0.000). CONCLUSION: Berberine had an antinociceptive effect on visceral hypersensitivity, and NO might play a role in this effect.