Activation of the aryl hydrocarbon receptor by berberine in HepG2 and H4IIE cells: Biphasic effect on CYP1A1

Berberine has long been considered a candidate for an antimalarial drug. It exerts a plethora of biological activities and has been used in the treatment of diarrhea and gastro-enteritis for centuries. Here we provide evidence that berberine activates the aryl hydrocarbon receptor (AhR) in human hepatoma (HepG2) and rat hepatoma cells stably transfected with a dioxin responsive element fused to the luciferase gene (H4IIE.luc). AhR was activated by high doses of berberine (10-50 microM) after 6 and 24 h of incubation as revealed by CYP1A1 mRNA expression (HepG2) and AhR-dependent luciferase activity (H4IIE.luc). Berberine induced nuclear translocation of AhR-GFP chimera transiently transfected to Hepa1c1c7 cells. In contrast, low doses of berberine (<1 microM) and prolonged times of the treatments (48 h) failed to produce any activation of AhR in H4IIE.luc cell line. HPLC analysis ruled out the hypothesis that the loss of berberine capacity to activate AhR in H4IIE.luc cells is due to metabolic inactivation of the alkaloid. We demonstrate that berberine is a potent inhibitor (IC50=2.5 microM) of CYP1A1 catalytic activity (EROD) in HepG2 cell culture and in recombinant CYP1A1 protein. Collectively, our results imply that while berberine activates the Ah receptor, it is accompanied by inactivation of the catalytic activity of CYP1A1 and occurs at concentrations that exceed those predicted to occur in vivo. Given these data, it appears that activation of the AhR pathway by berberine has a low toxicological potential.     

小檗碱对HepG2细胞葡萄糖激酶活性及其mRNA表达的影响

目的探讨小檗碱对HepG2细胞葡萄糖激酶活性和基因表达的影响。方法体外培养HepG2细胞,使用不同浓度的小檗碱(0,5,15,45,100μmol.L-1)以及作为阳性对照的生物素[1,2]组作用24h后,检测细胞增殖能力、葡萄糖激酶活性及其mRNA的表达、葡萄糖激酶下级产物糖原含量。结果小檗碱浓度低于5μmol.L-1时对HepG2细胞增殖无明显影响,在15μmol.L-1浓度以上对细胞增殖的抑制作用随浓度增加而加强;葡萄糖激酶的活性随着小檗碱的浓度增加而提高,而且HepG2细胞糖原含量以及葡萄糖激酶mRNA的表达在一定范围内也与小檗碱的浓度呈正相关。结论小檗碱能够提高HepG2细胞葡萄糖激酶的活性和葡萄糖激酶mRNA的表达。     

基于TLR4/MyD88/NF-κB信号通路研究黄连素对小鼠巨噬细胞极化的干预作用

目的:基于Toll样受体4(TLR4)/髓样分化因子88(MyD88)/核因子κB(NF-κB)信号通路研究黄连素对小鼠巨噬细胞极化的影响。方法:以小鼠巨噬细胞RAW264.7为对象,以阿托伐他汀钙为阳性对照,经脂多糖(LPS)诱导以复制炎症细胞模型,采用酶联免疫吸附测定法检测低、中、高剂量黄连素(5、10、20μmol/L)作用24 h后细胞培养液中肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、NF-κB含量,采用实时荧光定量聚合酶链反应法检测细胞中TLR4、MyD88 mRNA的表达水平,采用Western blotting法检测细胞中TLR4、MyD88、诱导型一氧化氮合酶(iNOS)、CD206蛋白的表达水平。结果:与空白对照组比较,LPS诱导组细胞培养液中TNF-α、IL-6、NF-κB含量,细胞中TLR4、MyD88 mRNA的相对表达量以及TLR4、MyD88、iNOS蛋白相对表达量均显著升高(P<0.05)。与LPS诱导组比较,阿托伐他汀钙组和黄连素中、高剂量组TNF-α、IL-6含量,TRL4、MyD88 mRNA及其蛋白的相对表达量以及各给药组NF-κB含量和i NOS蛋白的相对表达量均显著降低,且黄连素高剂量组NF-κB含量显著低于阿托伐他汀钙组(P<0.05);阿托伐他汀钙组和黄连素高剂量组CD206蛋白的相对表达量均显著升高,且黄连素高剂量组CD206蛋白的相对表达量显著高于阿托伐他汀钙组(P<0.05)。结论:不同剂量的黄连素均可不同程度地干预小鼠巨噬细胞极化,其机制可能与调控TLR4/MyD88/NF-κB信号通路有关。     

小檗碱及其类似物体外缺糖缺氧条件下对PC12细胞生存及其对COX-2抑制作用的比较

本文对小檗碱及其5个类似物对体外缺糖缺氧再灌注PC12细胞的保护作用及其对COX-2的抑制作用进行了实验观察,并就它们的构效关系进行了分析。造模方法为缺糖缺氧4小时复灌24小时。以MTT法检测小檗碱及其类似物对细胞的保护作用。以实时定量PCR和Western blot方法检测COX-2的mRNA和蛋白的表达。结果表明,小檗碱及其类似物均能够对抗缺糖缺氧再灌所引起的细胞损伤、抑制COX-2的表达。小檗碱和小檗红碱作用最强,其最大有效剂量为0.31μg/mL,其最小有效剂量分别为0.02和0.04μg/mL。巴马汀作用较弱。R2和R3位的亚甲二氧基是小檗碱及其类似物的活性基团。而且R2,R3,R9和R10位的亚甲二氧基影响小檗碱及其类似物对COX-2的亲和力。R9位的羟基取代不影响其活性。     

Berberine diminishes the side population and ABCG2 transporter expression in MCF-7 breast cancer cells

The plant alkaloid berberine has many biological activities including the ability to induce cell cycle arrest and apoptosis, making it a potentially useful agent for targeting cancer cells. We have analyzed the effects of berberine on MCF-7 breast cancer cells. Berberine was added to MCF-7 cells in culture, and proliferation, side population (SP) cells and expression of ABCG2 were examined. Berberine caused a dose-dependent reduction in proliferation. Hoechst 33,342 dye staining and FACS analysis revealed that berberine treatment caused a decrease in SP cells relative to untreated controls. In addition, berberine treatment was associated with a decrease in expression of ABCG2 relative to untreated controls. These results indicate that the growth inhibitory effects of berberine treatment on MCF-7 cells may be partly via effects on SP and ABCG2 expression. Further work is warranted to explore whether berberine may be a novel therapeutic drug useful for targeting breast cancer stem cells.     

Therapeutic effects of berberine in impaired glucose tolerance rats and its influence on insulin secretion

AIM: To explore the anti-diabetic effects of berberine and its influence on insulin secretion. METHODS: Impaired glucose tolerance rats induced by iv injection of streptozotocin 30 mg/kgwere treated with berberine 187.5 and 562.5 mg/kg while fed with high fat laboratory chow. After rats were treated for 4 weeks, oral glucose tolerance was determined, and for 8 weeks, the fasting blood glucose, insulin, lipid series were determined. In insulin secretion experiments, berberine 93.75, 187…     

Berberine inhibits HIF-1alpha expression via enhanced proteolysis

We have studied the antiangiogenic property of berberine. We showed that berberine could directly inhibit in vitro human umbilical vein endothelial cell (HUVEC) tube formation and migration. In addition, to determine whether berberine could influence the cross-talk between the gastric adenocarcinoma cell line SC-M1 and vascular endothelial cells, we performed modified confrontation culture experiments and showed that berberine (7.5 microM, 16 h) could inhibit the capacity of hypoxic SC-M1 cells to stimulate HUVEC migration. These results demonstrated berberine's antiangiogenic property and its clinical potential as an inhibitor of tumor angiogenesis. Parallel Western blot analyses revealed that berberine prevented hypoxic SC-M1 cultures from expressing vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF)-1alpha, two key factors in mediating tumor angiogenesis. However, overexpression of HIF-1alpha in SC-M1 cells dramatically reversed the inhibitory effect of berberine on SC-M1-induced in vitro HUVEC migration. These data indicated that HIF-1alpha repression is a critical step in the inhibitory effect of berberine on tumor-induced angiogenesis. Northern blot analyses plus pulse-chase assays revealed that berberine did not down-regulate HIF-1alpha mRNA but destabilized HIF-1alpha protein. We found that berberine-induced HIF-1alpha degradation was blocked by a 26S proteasome inhibitor. Moreover, immunoprecipitation and Western blot analyses showed that berberine increased the lysine-acetylated HIF-1alpha in hypoxic SC-M1 cultures. These data indicated that a proteasomal proteolytic pathway and lysine acetylation were involved in berberine-triggered HIF-1alpha degradation. In conclusion, our data provided molecular evidence to support berberine as a potent antiangiogenic agent in cancer therapy.     

Berberine inhibits growth of the breast cancer cell lines MCF-7 and MDA-MB-231

The effects of berberine on the behavior of breast tumors have not yet been established. To determine whether this compound is useful in the treatment of breast cancer, we analyzed the impact of berberine on the human breast cancer cell lines MCF-7 and MDA-MB-231 cells. Berberine was added to proliferating MCF-7 and MDA-MB-231 cells in culture. Following treatment, changes in cell growth characteristics such as proliferation, cell cycle duration, and the degree of apoptosis were assayed. Following berberine treatment, a time-dependent reduction in proliferation was observed in both cell lines at differing concentrations: 20 microM for MCF-7 and 10 microM for MDA-MB-231 cells. Annexin V staining showed an increase in apoptosis in both cell lines of 31 % in MCF-7 and 12 % in MDA-MB-231 cells compared to their respective controls. In addition, 12 % of the MCF-7 cells were arrested at G0/G1, compared to 62 % of control cells. These results demonstrate that treatment with berberine inhibits growth in both MDA-MB-231 and MCF-7 cells. In addition, they show that this partly occurs through the induction of apoptosis in MDA-MB-231 cells, and through both cell cycle arrest and induction of apoptosis in MCF-7 cells. Thus, berberine may be a novel therapeutic drug for breast cancer.     

Berberine induced down-regulation of matrix metalloproteinase-1, -2 and -9 in human gastric cancer cells (SNU-5) in vitro

Berberine, a yellow benzylisoquinoline alkaloid, is a constituent of Coptis chines and is commonly used in Chinese herbal medicine for patients with gastrointestinal disorders. The pharmacological effects of berberine include anti-inflammation, antidiarrhetic, antimalarial, and even antimicrobial activities. However, its mechanism of action on the cell migration of human gastric cancer SNU-5 cells is not fully understood. The effects of berberine on the percentage of viable cells were examined first and it was found that berberine induced dose-dependent inhibition in human gastric cancer SNU-5 cells. The effect of berberine on the levels of reactive oxygen species (ROS) and matrix metalloproteinase-1, -2, -7 and -9 was then examined using Western blotting and the results showed that berberine induced ROS production for up to 6 hours of incubation. It was also found that berberine induced downregulation of MMP-1 -2, and -9 but did not affect the level of MMP-7. The mRNA levels of MMPs in SNU-5 cells after treatment with berberine for 24 hours were investigated using a polymerase chain reaction and the results showed that berberine inhibited the gene expression of MMP-1, -2 and -9 in human SNU-5 cells but it did not affect MMP-7. In conclusion, berberine appears to exert its anticancer properties by inducing ROS production and prevention of cell migration via inhibition of the gene expression of MMP-1, -2 and -9 in human gastric cancer SNU-5 cancer cells.     

盐酸小檗碱对HL-60细胞增殖与分化的影响

目的　研究盐酸小檗碱对人早幼粒白血病HL 6 0细胞增殖与分化的影响。方法　应用生长曲线测定法、克隆形成实验检测药物对HL 6 0细胞生长抑制作用 ;细胞分化根据细胞形态、硝基蓝四氮唑 (NBT)还原能力、细胞表面标记的改变来决定 ;细胞周期变化用流式细胞仪测定。结果　HL 6 0细胞经小檗碱处理后生长明显受抑 ,呈时间和浓度依赖性。选择 1、2、4、8mg·L-1小檗碱作用于HL 6 0细胞 ,动态观察发现 ,HL 6 0细胞向成熟细胞分化 :细胞核变小 ,核浆比减少 ;NBT还原能力增强 ;CD11b表达升高。细胞周期分析发现 ,小檗碱处理后细胞阻滞于G0 /G1期 ,S期细胞明显减少。结论　盐酸小檗碱可抑制HL 6 0细胞的增殖 ,并诱导HL 6 0细胞向成熟细胞分化。     

盐酸小檗碱抑制结肠癌细胞环氧化酶-2/钙离子途径

目的探讨盐酸小檗碱对结肠癌细胞系生长、增殖的作用及环氧化酶2/钙离子途径的影响,为阐明盐酸小檗碱作为一种新的结肠癌化学治疗药物进行理论上的准备。方法0.1、0.3、3.0、30.0μmol·L-1的盐酸小檗碱加入到HT29结肠癌细胞系培养液中。MTT法检测细胞的生长和增殖,RTPCR法检测环氧化酶2mRNA,免疫细胞化学法检测环氧化酶2蛋白质表达,ELISA法检测前列腺素E2的含量,免疫荧光分光光度法检测细胞内钙离子浓度([Ca2+]i)。结果盐酸小檗碱在浓度大于0.3μmol·L-1时则有明显的量效关系抑制细胞的生长、增殖;在浓度大于0.3μmol·L-1时对环氧化酶2mRNA水平和蛋白的表达有明显的抑制作用;对前列腺素E2的生成有抑制作用,可以降低细胞内钙离子浓度。结论盐酸小檗碱通过抑制细胞内钙离子浓度进而通过某些途径抑制COX2在mRNA水平和蛋白质水平的表达,同时也抑制COX2活性进而抑制前列腺素E2的生成,这可能是其抑制HT29细胞生长和增殖的机制之一。     

Protective effect of berberine on cyclophosphamide-induced haemorrhagic cystitis in rats

The urotoxicity of cyclophosphamide and the protective effect of the herb berberine were investigated in this study. Administration of 150 mg/kg cyclophosphamide intraperitoneally caused a serious haemorrhagic cystitis in rats after 12 hr, including bladder oedema, haemorrhage, and dramatic elevation of nitric oxide metabolites (nitrite+nitrate) in urine and in plasma. To explore whether cyclophosphamide-induced cystitis could be prevented by berberine, rats were pretreated with a single dose or two doses of berberine at 50, 100, or 200 mg/kg intraperitoneally then challenged with cyclophosphamide (150 mg/kg, intraperitoneally). The results indicated that pretreatment of rats with berberine could reduce cyclophosphamide-induced cystitis in a dose-dependent manner. Furthermore, we found that two doses of berberine showed greater protection against cyclophosphamide urotoxicity than when given a single dose. In addition, our data shows that a single dose of 200 mg/kg berberine, or two doses of 100, and 200 mg/kg berberine could completely block cyclophosphamide-induced bladder oedema and haemorrhage, as well as nitric oxide metabolites increase in rat urine and plasma. In conclusion, our findings suggest that berberine could be a potential effective drug in the treatment of cyclophosphamide-induced cystitis, and provides us with the bright hope in the prevention and treatment of cyclophosphamide urotoxicity.     

Inhibitory effects of alprostadil (prostaglandin E1) incorporated in lipid microspheres of soybean oil on intimal hyperplasia following balloon injury in rabbits

The present study was performed to assess the inhibitory effects of alprostadil (CAS 745-65-3, prostaglandin E1, PGE1) incorporated in lipid microspheres (here-in-after referred to as lipo PGE1; Palux inj.) on intimal thickening following balloon injury in the carotid artery of normal rabbits. Lipo PGE1 was given intravenously to animals twice a day at doses of 20 or 40 micrograms/kg/day from ballooning (day 1) until day 3, and at half these doses from day 4 to day 20. The carotid artery was removed for histopathological staining on the next day (day 21) after the last administration. Lipo PGE1 significantly reduced both the intimal/medial are (I/M) ratio and stenosis ratio by about half in the 40 micrograms/kg/day on day 21 after ballooning, compared with the vehicle group. Infiltration of macrophage, expression of proliferating cell nuclear antigen (PCNA)-positive cells was inhibited by the administration of lipo PGE1 on day 3 after ballooning. Adhesion of platelets to injured arterial walls was also inhibited on day 3. Lipo PGE1 at 40 micrograms/kg/day exerted more potent inhibitory effects on I/M and stenosis ratios and histopathological changes such as infiltration of macrophage and expression of PCNA-positive cells than at 20 micrograms/kg/day. These findings suggest that lipo PGE1 inhibits the intimal hyperplasia after balloon injury in rabbit carotid artery, possibly by inhibiting platelet functions.     

Magnoliae Cortex inhibits intimal thickening of carotid artery through modulation of proliferation and migration of vascular smooth muscle cells

Endovascular injury leads to proliferation and migration of vascular smooth muscle cells from the media to the intima leading to the intimal thickening. The objective of this study was to examine the effect of Magnoliae Cortex extract (MOE) on intimal thickening of rat carotid artery injured by balloon endothelial denudation. MOE was administered orally using gastric sonde at three different doses MOE200 (200 mg/kg), MOE400 (400 mg/kg), and MOE800 (800 mg/kg) for 14 days from the day of balloon injury. Also, in vitro assays of proliferation, migration and expression of matrix metalloproteinase-2 (MMP-2) in human aortic smooth muscle cells (HASMCs) were carried out using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell boyden chamber method and gelatin zymography, respectively. Oral administration of MOE400 and MOE800 for 14 days significantly inhibited intimal area, intimal/medial ratio (I/M), stenosis rate, expression of proliferating cell nuclear antigen (PCNA), MMP-2, and -9 in denudated rat carotid artery. Our in vitro assays revealed that MOE dose dependently inhibited proliferation, migration and expression of MMP-2 in HASMCs. Thus, the results suggest that MOE can be considered as a therapeutic value in the prevention of atherosclerosis because restenosis after percutaneous transluminal coronary angioplasty (PTCA) is supposed to be 'accelerated atherosclerosis'.     

Protective Effect of Berberine on Cyclophosphamide‐Induced Haemorrhagic Cystitis in Rats

Abstract: The urotoxicity of cyclophosphamide and the protective effect of the herb berberine were investigated in this study. Administration of 150 mg/kg cyclophosphamide intraperitoneally caused a serious haemorrhagic cystitis in rats after 12 hr, including bladder oedema, haemorrhage, and dramatic elevation of nitric oxide metabolites (nitrite+nitrate) in urine and in plasma. To explore whether cyclophosphamide‐induced cystitis could be prevented by berberine, rats were pretreated with a single dose or two doses of berberine at 50, 100, or 200 mg/kg intraperitoneally then challenged with cyclophosphamide (150 mg/kg, intraperitoneally). The results indicated that pretreatment of rats with berberine could reduce cyclophosphamide‐induced cystitis in a dose‐dependent manner. Furthermore, we found that two doses of berberine showed greater protection against cyclophosphamide urotoxicity than when given a single dose. In addition, our data shows that a single dose of 200 mg/kg berberine, or two doses of 100, and 200 mg/kg berberine could completely block cyclophosphamide‐induced bladder oedema and haemorrhage, as well as nitric oxide metabolites increase in rat urine and plasma. In conclusion, our findings suggest that berberine could be a potential effective drug in the treatment of cyclophosphamide‐induced cystitis, and provides us with the bright hope in the prevention and treatment of cyclophosphamide urotoxicity.     

Effect of baicalin and berberine on transport of nimodipine on primary-cultured, rat brain microvascular endothelial cells

AIM: To investigate whether baicalin and berberine affects the transport of nimodipine (NMD) across the blood-brain barrier (BBB). METHODS: Primary-cultured, rat brain microvascular endothelial cells (rBMEC) were used as an in vitro model of the BBB. When cells became confluent, the steady-state uptake of NMD by rBMEC with or without baicalin and berberine was measured. The effects of baicalin and berberine on the efflux of NMD from rBMEC were also studied. RESULTS: Baicalin (2-5 microg/mL) increased the uptake of NMD, and baicalin (10-20 microg/mL) decreased the uptake. The steady-state uptake of NMD was higher than that of control group in the presence of 0.01-1 microg/mL berberine, but was lower in the presence of 2-10 microg/mL berberine. CONCLUSION: The bidirectional effect of baicalin and berberine on the uptake of NMD by rBMEC was found. Higher concentration showed an inhibitory effect, and lower concentration demonstrated an increasing effect.     

黄连素对结肠平滑肌细胞膜钙激活钾通道和延迟整流钾通道的影响

目的　研究黄连素对结肠平滑肌细胞膜钙离子激活钾通道 (IK(Ca) )和延迟整流钾通道 (IK(V) )的影响以初步探讨其治疗运动性腹泻的机制。方法　酶解法急性分离单个豚鼠结肠平滑肌细胞 ,运用膜片钳方法检测 10、5 0、10 0 μmol·L-1的黄连素对结肠平滑肌细胞膜IK(Ca) 和IK(V) 的影响。结果　 10、5 0、10 0 μmol·L-1的黄连素可抑制豚鼠单个结肠平滑肌细胞膜IK(Ca) (P <0 0 1) ,当阶跃刺激为 +80mV时 ,其IK(Ca) 分别为生理盐水对照组的 (6 8 2 0± 5 17) % ,(5 5 89± 1 6 1) % ,(4 8 0 8± 2 4 5 ) % (P <0 0 1) ;10、5 0、10 0 μmol·L-1的黄连素可抑制豚鼠单个结肠平滑肌细胞膜IK(V) (P <0 0 1) ,当阶跃刺激为 +80mV时 ,其IK(V) 分别为生理盐水对照组的 (77 0 6± 6 4 2 ) % ,(6 8 6 7± 6 79) % ,(6 1 0 7±7 72 ) % (P <0 0 1)。结论　Ber能抑制豚鼠结肠平滑肌钙离子激活钾通道和延迟整流钾通道的开放 ,这可能是其治疗运动性腹泻的机制之一。     

Biochemical effects of berberine.

The benzodioxoloquinolizine alkaloid berberine inhibited the biosyntheses of UNA, RNA, proteins and lipids, as well as the oxidation of glucose [¹⁴C] to ¹⁴CO₂, when incubated with S 180 cells in vitro. The synthesis of proteins and of RNA was the most sensitive of these parameters to the action of berberine. Only marginal inhibition of protein biosynthesis occurred in vitro when both drug and glycine [1-¹⁴C] were injected. This difference was reflected in the failure of berberine to inhibit the growth of S 180 in mice, despite an inhibitory action in culture. The discrepancy may involve the effects of glucose. When levels of glucose similar to those reported in biological fluids were added to incubation media in vitro, the inhibition of protein biosynthesis by berberine was prevented. Glucose and berberine showed mutual antagonism for uptake by S 180 cells. Phlorizin, an inhibitor of the active transport of glucose, inhibited the uptake of berberine. Inhibition by berberine of the biosynthesis of macromolecules may reflect such primary actions as inhibition of glucose utilization and interaction with nucleic acids.     

Effect of berberine on proliferation, biosynthesis of macromolecules, cell cycle and induction of intercalation with DNA, dsDNA damage and apoptosis in Ehrlich ascites carcinoma cells

Our primary aim was to study berberine, a potential anti-cancer drug, for its cytotoxic and antiproliferative activity in-vitro using Ehrlich ascites carcinoma (EAC) cells. Cytotoxicity was measured by the growth inhibition assay. We investigated the effect of berberine on the biosynthesis of macro-molecules (DNA, RNA, proteins), cell cycle effects and induction of dsDNA damage and apoptosis in berberine-treated EAC cells. Our results showed that berberine acts cytotoxically on EAC cells. The cytotoxicity was directly concentration and time dependent. The highest cytotoxic concentrations (100 and 50 microg mL(-1)) induced intercalation of berberine with DNA, formation of dsDNA breaks, inhibition of DNA synthesis and death of EAC cells. A concentration of 10 mug mL(-1) induced clear apoptotic cell death, which was followed by inhibition of protein synthesis.     

小檗碱对NIT-1细胞胰岛素分泌和葡萄糖激酶活性的影响

本文探讨小檗碱对NIT-1细胞胰岛素分泌的影响及其分子机制。采用不同浓度小檗碱干预NIT-1细胞后，以放射免疫法、液体闪烁计数法、酶法分析及Western blotting分别检测其胰岛素水平、葡萄糖利用、葡萄糖激酶(GK)活性、GK和葡萄糖激酶调节蛋白(GKRP)的表达。结果表明，在高浓度葡萄糖刺激下，与空白对照组相比，小檗碱组的NIT-1细胞胰岛素分泌增加、葡萄糖利用活跃，且GK酶活性增强、GK表达增加，而GKRP表达降低(P<0.05)。结果表明，小檗碱促进NIT-1细胞高浓度葡萄糖诱导的胰岛素分泌，可能与其作为GK激活剂，使NIT-1细胞葡萄糖利用增加、GK酶活性及表达增强有关。