SDF7, a group of Scoparia dulcis Linn. derived flavonoid compounds,stimulates glucose uptake and regulates adipocytokines in 3T3-F442a adipocytes

Ethnopharmacology relevance

Adipocytes are major tissues involved in glucose uptake second to skeletal muscle and act as the main adipocytokines mediator that regulates glucose uptake mechanism and cellular differentiation. The objective of this study were to examine the effect of the SDF7, which is a fraction consists of four flavonoid compounds (quercetin: p-coumaric acid: luteolin: apigenin=8: 26: 1: 3) from Scoparia dulcis Linn., on stimulating the downstream components of insulin signalling and the adipocytokines expression on different cellular fractions of 3T3-F442a adipocytes.

Material and methods

Morphology and lipid accumulation of differentiated 3T3-F442a adipocytes by 100 nM insulin treated with different concentrations of SDF7 and rosiglitazone were examined followed by the evaluation of glucose uptake activity expressions of insulin signalling downstream components (IRS-1, PI3-kinase, PKB, PKC, TC10 and GLUT4) from four cellular fractions (plasma membrane, cytosol, high density microsome and low density microsome). Next, the expression level of adipocytokines (TNF-α, adiponectin and leptin) and immunoblotting of treated 3T3-F442 adipocytes was determined at 30 min and 480 min. Glucose transporter 4 (GLUT4) translocation of 3T3-F442a adipocytes membrane was also determined. Lastly, mRNA expression of adiponectin and PPAR-γ of 3T3-F442a adipocytes were induced and compared with basal concentration.

Results

It was found that SDF7 was able to induce adipocytes differentiation with great extends of morphological changes, lipid synthesis and lipid stimulation in vitro. SDF7 stimulation of glucose transport on 3T3-F442a adipocytes are found to be dose independent, time-dependent and plasma membrane GLUT4 expression-dependent. Moreover, SDF7 are observed to be able to suppress TNF-α and leptin expressions that were mediated by 3T3-F442a adipocytes, while stimulated adiponectin secretion on the cells. There was a significant expression (p<0.01) of protein kinase C and small G protein TC10 on 3T3-F442a adipocytes upon treatment with SDF7 as compared to the control. SDF7 was also found to be effective in stimulating adiponectin and PPAR-γ mRNA upregulation at 50 µg/ml.

Conclusion

SDF7 exhibited good lipogenesis, adiponectinesis and glucose uptake stimulatory properties on 3T3-F442a adipocytes.     

Glucose uptake-stimulatory activity of Amomi Semen in 3T3-L1 adipocytes

Amomi Semen has been used as a folk remedy for the treatment of diabetes in Korea. The aim of this study was to examine whether it had an enhancing effect on glucose uptake, an essential process of insulin action. Its aqueous ethanolic extract significantly stimulated glucose uptake in 3T3-L1 adipocytes at the concentration of 0.5 mg/ml. The extract significantly potentiated insulin-stimulated glucose uptake with a dose-dependent manner at a concentration range from 0.02 to 0.5 mg/ml. The results suggest that the antidiabetic action of Amomi may be mediated through the stimulation of glucose uptake and the potentiation of insulin action.     

Ibervillea sonorae (Cucurbitaceae) induces the glucose uptake in human adipocytes by activating a PI3K-independent pathway

Ethnopharmacological relevance

Ibervillea sonorae (S. Watson) Greene (Cucurbitaceae), a plant used for the empirical treatment of type 2 diabetes in México, exerts antidiabetic effects on animal models but its mechanism of action remains unknown. The aim of this study is to investigate the antidiabetic mechanism of an Ibervillea sonorae aqueous extract (ISE).

Materials and methods

Non-toxic ISE concentrations were assayed on the glucose uptake by insulin-sensitive and insulin-resistant murine and human cultured adipocytes, both in the absence or the presence of insulin signaling pathway inhibitors, and on murine and human adipogenesis. Chemical composition of ISE was examined by spectrophotometric and HPLC techniques.

Results

ISE stimulated the 2-NBDGlucose uptake by mature adipocytes in a concentration-dependent manner. ISE 50 µg/ml induced the 2-NBDG uptake in insulin-sensitive 3T3-F442A, 3T3-L1 and human adipocytes by 100%, 63% and 33%, compared to insulin control. Inhibitors for the insulin receptor, PI3K, AKT and GLUT4 blocked the 2-NBDG uptake in murine cells, but human adipocytes were insensitive to the PI3K inhibitor Wortmannin. ISE 50 µg/ml also stimulated the 2-NBDG uptake in insulin-resistant adipocytes by 117% (3T3-F442A), 83% (3T3-L1) and 48% (human). ISE induced 3T3-F442A adipogenesis but lacked proadipogenic effects on 3T3-L1 and human preadipocytes. Chemical analyses showed the presence of phenolics in ISE, mainly an appreciable concentration of gallic acid.

Conclusion

Ibervillea sonorae exerts its antidiabetic properties by means of hydrosoluble compounds stimulating the glucose uptake in human preadipocytes by a PI3K-independant pathway and without proadipogenic effects.     

胡柚果肉不同极性提取物对3 T3-L1脂肪细胞葡萄糖摄取率、白细胞介素-6及游离脂肪酸的影响

目的：用不同极性的溶剂对胡柚果肉进行依次分离,得到5个不同极性组分,将不同极性组分进行促进3 T3-L1脂肪细胞葡萄糖消耗、降低白细胞介素-6和游离脂肪酸分泌的活性组分的筛选及其机制的研究。方法：采用溶剂法将胡柚果肉分离成5个不同极性的组分;诱导分化3 T3-L1脂肪细胞,成熟后添加不同浓度的提取组分作用48 h,检测细胞培养液中葡萄糖、细胞白介素-6和游离脂肪酸含量,比较加药培养前后的葡萄糖、细胞白介素-6和游离脂肪酸含量,筛选出具有促进3 T3-L1脂肪细胞葡萄糖消耗、降低白细胞介素-6和游离脂肪酸分泌的活性组分。结果：胡柚果肉中极性组分占（88.96±2．34）％,而非极性组分的含量较少,胡柚果肉石油醚组分、二氯甲烷组分、乙酸乙酯组分和水组分均能显著促进脂肪细胞对葡萄糖的摄取,二氯甲烷组分、乙酸乙酯组分、正丁醇组分和水组分能够显著降低脂肪细胞白介素-6和游离脂肪酸的水平。结论：胡柚果肉可通过促进3 T3-L1脂肪细胞对葡萄糖的消耗,降低细胞因子白细胞介素-6和游离脂肪酸水平调节血糖。     

Peroxisome proliferator-activated receptor gamma transactivation-mediated potentiation of glucose uptake by Bai-Hu-Tang

ETHNOPHARMACOLOGICAL RELEVANCE: The molecular mechanism of a traditional hypoglycemic Chinese herbal formula. AIM OF THE STUDY: To explore the glucose uptake effect as well as the mechanism(s) of action of Bai-Hu-Tang (BHT), a traditional Chinese herbal formula, composed of anemarrhena, gypsum, licorice and rice. MATERIALS AND METHODS: Differentiated 3T3-L1 adipocytes were treated with vehicle, insulin or insulin plus different concentrations of BHT. The 2-deoxy-[(3)H] glucose uptake assay was performed to measure the amount of glucose uptake. To explore the mechanism(s) of glucose uptake of BHT, we used two insulin signaling transduction inhibitors, N-Acetyl-Leu-Leu-Norleu-al (ALLN), a calpain inhibitor, and LY 294002, a phosphatidylinositol (PI)3-kinase inhibitor, to test if the glucose uptake effect was mediated by the insulin signaling pathway. We then used Western blot analysis to re-confirm the result of the insulin signaling inhibition assay. Finally, reporter chimera assay of HuH-7 cells was used to measure the peroxisome proliferator-activated receptor gamma (PPARgamma) activation by BHT. RESULTS: BHT potentiated insulin-stimulated glucose uptake in 3T3-L1 adipocytes. The effect of BHT-stimulated glucose uptake was neither inhibited by ALLN nor by LY 294002. The protein expression of PI3 kinase pathway did not change after BHT stimulation. PPARgamma activation was elevated by 67.7+/-32% (p<0.05) in HuH-7 cells treated with 0.8 microg/ml of BHT. CONCLUSIONS: BHT stimulated glucose uptake in 3T3-L1 adipocytes. This effect was via PPARgamma activation rather than via the insulin signaling pathway.     

肿瘤坏死因子-α诱导3T3-L1脂肪细胞胰岛素抵抗模型的建立

目的:应用肿瘤坏死因子d(TNF-α)诱导3T3-L1脂肪细胞,探讨建立可靠胰岛素抵抗(IR)细胞模型的方法.方法:3T3-L1前脂肪细胞经3-异丁基-1-甲基黄嘌呤、地塞米松、胰岛素诱导分化成3T3-L1脂肪细胞,将其与20,10,5μg·L-1TNF-α共孵育,100 nmol·L-1胰岛素作用30 min刺激脂肪细胞糖转运.以葡萄糖氧化酶法测定培养基上清液葡萄糖含量,观察TNF-α对脂肪细胞糖摄取的影响,鉴定IR模型.结果:TNF-α抑制胰岛素诱导前、后的脂肪细胞糖转运,抑制作用呈剂量依赖性,其中20 μg·L-1TNF-α的抑制率分别为79.2％和81.4％(P＜0.05).结论:肿瘤坏死因子α可诱导3T3-L1脂肪细胞产生IR,这种细胞模型简便、可靠.     

地黄寡糖对3T3-L1脂肪细胞增殖及胰岛素抵抗的作用

目的：探讨地黄寡糖对脂肪细胞增殖和胰岛素抵抗的影响。方法：培养3T3-L1前脂肪细胞,用四甲基偶氮唑盐（MTT）方法检测3T3-L1前脂肪细胞及脂肪细胞的增殖情况,同时采用地塞米松诱导3T3-L1脂肪细胞建立胰岛素抵抗模型,检测地黄寡糖对细胞培养基中葡萄糖浓度的影响。结果：在DMEM高糖培养基中,地黄寡糖可促进3T3-L1前脂肪细胞增殖,抑制3T3-L1脂肪细胞增殖,作用呈明显量效关系；使3T3-L1前脂肪细胞及3T3-L1脂肪细胞葡萄糖消耗量增加,呈明显量效关系；地黄寡糖能明显增加胰岛素抵抗3T3-L1脂肪细胞培养基中的葡萄糖消耗量,增强对胰岛素的敏感性。结论：地黄寡糖可以促进前脂肪细胞的增殖,抑制脂肪细胞的增殖,地黄寡糖对地塞米松诱导的3T3-L1脂肪细胞胰岛素抵抗具有明显的改善作用。     

葛根素对3T3-L1前脂肪细胞分化及胰岛素抵抗模型糖代谢的影响

目的:研究葛根素(Pur)对3T3-L1前脂肪细胞增殖、分化的影响,以及在胰岛素抵抗状态下对3T3-L1脂肪细胞葡萄糖代谢的影响。方法:不同浓度Pur干预3T3-L1细胞,MTT法检测其对细胞增殖的影响;油红O染色法检测其对前脂肪细胞分化过程及成脂的影响;地塞米松诱导3T3-L1细胞建立胰岛素抵抗模型,用不同浓度Pur进行干预,测定细胞的葡萄糖消耗量。结果:Pur(3～300μmol/L)对3T3-L1前脂肪细胞增殖无明显影响;Pur(30～300μmol/L)促进3T3-L1细胞的分化成脂,增加胰岛素抵抗状态下3T3-L1脂肪细胞的葡萄糖代谢,且具有量效关系。结论:Pur能够促进3T3-L1细胞的分化成脂,增加胰岛素抵抗状态下3T3-L1脂肪细胞的葡萄糖代谢,改善胰岛素抵抗。     

Tinospora cordifolia preserves pancreatic beta cells and enhances glucose uptake in adipocytes to regulate glucose metabolism in diabetic rats

The purpose of this study was to evaluate the pancreatic beta cell protective and glucose uptake enhancing effect of the water extract of Tinospora cordifolia stem (TCSE) by using rat insulinoma (RIN)‐m5F cells and 3 T3‐L1 adipocytes. RIN‐m5F cells were stimulated with interleukin‐1β and interferon‐γ, and the effect of TCSE on insulin secretion and cytokine‐induced toxicity was measured by ELISA and MTT assay, respectively. The glucose uptake and protein expression were measured by fluorometry and western blotting. Antidiabetic effect of TCSE was measured using streptozotocin‐induced diabetic rats. TCSE dose dependently increased cell viability and insulin secretion in RIN‐m5F cells. In addition, TCSE increased both the glucose uptake and glucose transporter 4 translocation in 3 T3‐L1 adipocytes via PI3K pathway. Finally, TCSE significantly lowered blood glucose and diet intake and increased body weight in streptozotocin‐induced diabetic rats. The level of serum insulin and hepatic glycogen was increased, whereas the level of serum triglyceride, total cholesterol, dipeptidyl peptidase‐4, and thiobarbituric acid reactive substances was decreased in TCSE‐administered rats. TCSE also increased glucose transporter 4 protein expression in the adipose tissue and liver of TCSE‐fed diabetic rats. Our results suggested that TCSE preserved RIN‐m5F cells from cytokine‐induced toxicity and enhanced glucose uptake in 3 T3‐L1 adipocytes, which may regulate glucose metabolism in diabetic rats.     

小檗碱与梓醇及其配伍对胰岛素抵抗3T3-L1脂肪细胞葡萄糖转运子4蛋白及C-Cb1相关蛋白表达的影响

目的观察梓醇与小檗碱及其配伍对胰岛素抵抗3T3-L1脂肪细胞葡萄糖消耗及这一过程中葡萄糖转运子4(Glut4)和C-Cb1相关蛋白(CAP)表达的影响。方法采用高糖联合高胰岛素诱导3T3-L1脂肪细胞产生胰岛素抵抗(IR),分别给予小檗碱、梓醇、小檗碱 梓醇、盐酸罗格列酮进行干预,以葡萄糖氧化酶法检测培养液中葡萄糖消耗量,以Western Blotting法检测Glut4和CAP蛋白的表达。结果与模型组相比,小檗碱能增加培养液中葡萄糖的消耗,但对Glut4蛋白的表达无影响;梓醇、小檗碱 梓醇均能显著增加培养液中葡萄糖的消耗,并使细胞中Glut4蛋白的表达增强,且小檗碱 梓醇组的效应优于梓醇组及小檗碱组;与模型组相比,小檗碱与梓醇及其配伍对CAP的表达没有显著性影响。结论小檗碱、梓醇及其配伍能改善IR 3T3-L1脂肪细胞的胰岛素活性,其作用机制与罗格列酮不同。     

Sarcopoterium spinosum extract as an antidiabetic agent: In vitro and in vivo study

Ethnopharmacological relevance

Sarcopoterium spinosum (L.) sp., a common plant in the Mediterranean region, is widely used as an antidiabetic drug by Bedouin healers. However, the antidiabetic properties of Sarcopoterium spinosum had not been fully validated using scientific tools.

Aim of the study

To determine the effectiveness of Sarcopoterium spinosum extract as an antidiabetic agent in vitro and in vivo.

Materials and methods

RINm pancreatic β-cells, L6 myotubes, 3T3-L1 adipocytes and AML-12 hepatocytes were treated with an aqueous Sarcopoterium spinosum extract (0.001–10 mg/ml). The effect of the extract on specific physiological functions, including insulin secretion, pancreatic β-cell viability, GSK3β phosphorylation, lipolysis and glucose uptake was measured. In vivo studies were performed using KK-A^y mice, given the extract for several weeks. IPGTT was performed, and plasma insulin, FFA, food consumption and body weight were measured. In addition, diabetic KK-A^y mice were given a single dose of the extract, and IPGTT was performed.

Results

Sarcopoterium spinosum extract increased basal and glucose/forskolin-induced insulin secretion in RINm cells, and increased cell viability. The extract inhibited lipolysis in 3T3-L1 adipocytes, and induced glucose uptake in these cells as well as in AML-12 hepatocytes and L6 myotubes. GSK3β phosphorylation was also induced in L6 myotubes, suggesting increased glycogen synthesis. Sarcopoterium spinosum extract had a preventive effect on the progression of diabetes in KK-A^y mice. Catechin and epicatechin were detected in Sarcopoterium spinosum extract using hyphenated LC–MS/MS.

Conclusions

Sarcopoterium spinosum extract has effects that mimic those of insulin and provide the basis for antidiabetic activity of the extract.     

小檗碱对3T3-L1脂肪细胞脂联素表达的影响

目的:探讨小檗碱和胰岛素对3T3-L1脂肪细胞脂联素表达的影响。方法:检测分别经小檗碱及胰岛素处理后3T3 L1脂肪细胞脂联素表达水平改变,以β actin为内对照,半定量法RT PCR测定脂联素mRNA表达。结果:经小檗碱(10μmol·L^-1)干预后3T3 L1脂肪细胞脂联素表达显著增加(P<0.05),加入胰岛素后脂联素的表达受到抑制,高浓度胰岛素有显著抑制作用(P<0.05)。结论:体外实验中,小檗碱使3T3-L1脂肪细胞脂联素的表达增加,而胰岛素可抑制小檗碱增加脂联素表达的作用。     

Ginsenoside Re reduces insulin resistance through activation of PPAR-γ pathway and inhibition of TNF-α production

Ethnopharmacological relevance

Panax ginseng is a well-known traditional Chinese medicine and has been used for treatment of various diseases for more than four thousand years in Asia. Ginseng saponins or ginsenosides, the active constituents are reported to possess antidiabetic activity, but their antihyperglycemic mechanisms are not fully elucidated. In the present study, the mechanisms of action of ginsenoside Re were investigated in vitro models.

Materials and methods

3T3-L1 cells were chosen as the model to investigate the molecular mechanisms of action of ginsenoside Re. Influence of ginsenoside Re on the adipogenesis was examined by determining TG levels in 3T3-L1 adipocytes by the method of TG oxidation enzyme. Glucose uptake in 3T3-L1 cells stimulated by insulin in the absence or presence of ginsenoside Re were quantified by measuring ³H-2-deoxy-d-glucose levels. Cytokine proteins released into the medium including adiponectin and TNF-α were tested using respective ELISA kits. In addition, real time RT-PCR was conducted to investigate the expression changes of PPAR-γ and its responsive genes, ap2, adiponectin, IRS-1, GLUT4 and TNF-α. And western blot analysis was performed to determine the translocation of GLUT4. Finally, effects of ginsenoside Re on NO production in 3T3-L1 adipocytes and in macrophages were investigated through measurement of nitrite concentration by Griess reagent.

Results

Ginsenoside Re induced adipogenesis of 3T3-L1 adipocytes by accumulating TG, increased glucose uptake and up-regulated PPAR-γ2, IRS-1, ap2 and adiponectin genes expressions. Meanwhile, Re also increased production and release of adiponectin. Although having no effects on GLUT4 gene expression, Re facilitated GLUT4 protein translocation to the membranes. In addition, Re inhibited the expression and release of TNF-α. Finally, Re did not show inhibitory effects on NO production both in 3T3-L1 cells stimulated by LPS, TNF-α and IFN-γ and in LPS-stimulated mouse peritoneal macrophages.

Conclusions

Ginsenoside Re exhibited the action of reducing insulin resistance through activation of PPAR-γ pathway by directly increasing the expressions of PPAR-γ2 and its responsive genes, adiponectin, IRS-1, ap2, inhibiting TNF-α production and facilitating the translocation of GLUT4 to promote glucose uptake and disposal in 3T3-L1 adipocytes.     

Interaction of baicalin with berberine for glucose uptake in 3T3-L1 adipocytes and HepG2 hepatocytes

Ethnopharmacological relevance

Baicalin and berberine are important coexisting constituents of the combination of Radix Scutellariae and Rhizoma Coptidis, known as scutellaria–coptis herb couple (SC), which has heat clearing and detoxifying effects. The aims of the present study were to investigate the effects of the combination of baicalin+berberine on glucose uptake in 3T3-L1 adipocytes or HepG2 cells.

Materials and methods

Insulin-resistant adipocytes and hepatocytes models were established. Glucose consumption was assayed to evaluate the effects of berberine, baicalin, and berberine+baicalin on glucose uptake, and the interaction of baicalin with berberine for glucose uptake was evaluated in 3T3-L1 adipocytes or HepG2 cells. Moreover, the effects of baicalin on the dose–effect relationship of berberine for glucose uptake was also evaluated in 3T3-L1 adipocytes.

Results

The results of the present study demonstrated that berberine increased glucose consumption in 3T3-L1 adipocytes and HepG2 hepatocytes in a dose-dependent manner. In contrast, statistical analyses indicated that baicalin (in doses up to 100 μmol/L) produced no obvious effect. The effect of berberine+baicalin on glucose uptake was better than that of berberine or baicalin alone, which indicated that berberine and baicalin had the trend of synergetic effect on glucose uptake. Furthermore, these results showed that the synergistic effect occurred in a specific dose range, while the antagonistic effect was present in another dose range in the presence of 10 μmol/L baicalin. Interestingly, the entire dose–response curves of berberine shifted down in the presence of 100 μmol/L baicalin, and baicalin antagonised the effect of berberine on glucose uptake in 3T3-L1 adipocytes.

Conclusions

The results of the present study showed that berberine dose-dependently increased glucose consumption in 3T3-L1 adipocytes and HepG2 hepatocytes. Furthermore, interaction of baicalin with berberine was additive at low doses of baicalin and antagonistic at higher baicalin doses. Thus, it is possible that baicalin is a partial agonist. These results provided a basis for the study of the TCM compatibility mechanism and a new insight into the application for Gegen Qinlian Decoction (GGQLD) or SC in the clinic.     

没食子儿茶素促进脂肪细胞吸收葡萄糖研究

目的探讨没食子儿茶素对脂肪细胞在高浓度葡萄糖条件下吸收葡萄糖的作用。方法应用3T3-L1前脂肪细胞分化模型,测定在脂肪细胞中没食子儿茶素对葡萄糖吸收的作用和对3T3-L1前脂肪细胞分化的影响。结果没食子儿茶素可促进脂肪细胞中高浓度葡萄糖(30 mmol/L)条件下由胰岛素刺激的葡萄糖吸收,加快3T3-L1前脂肪细胞的分化。结论没食子儿茶素可增加脂肪细胞葡萄糖吸收并促进3T3-L1前脂肪细胞分化,提示没食子儿茶素可有效改变血糖浓度和改善胰岛素抵抗。     

Cornus kousa F.Buerger ex Miquel increases glucose uptake through activation of peroxisome proliferator-activated receptor γ and insulin sensitization

Aim of the study

Cornus kousa F.Buerger ex Miquel, an oriental medicinal plant, has been traditionally used for the treatment of hyperglycemia, but its molecular mechanism remains unknown. The goal of this study was to investigate the peroxisome proliferator-activated receptor γ (PPARγ) ligand-binding activity of Cornus kousa and to determine the effects of Cornus kousa on insulin sensitization in 3T3-L1 cells for the treatment of type 2 diabetes.

Materials and methods

PPARγ luciferase transactivation assay was used to evaluate the PPARγ ligand-binding activity of Cornus kousa leaf extract. Western blot analysis, oil Red O staining, and glucose uptake assay were performed to evaluate PPARγ agonistic activity and insulin sensitizing effects of Cornus kousa leaf extract (CKE) in 3T3-L1 cells.

Results

CKE increased PPARγ ligand-binding activity in a dose-dependent manner. In addition, CKE enhanced adipogenesis and the expression of PPARγ target proteins, including glucose transporter 4 (GLUT4) and adiponectin, as well as proteins involved in adipogenesis, including PPARγ and CCAAT/enhancer binding protein α (C/EBPα) in 3T3-L1 adipocytes. Furthermore, CKE led to significant induction of glucose uptake and stimulated insulin signaling, but not to activation of AMP-activated protein kinase (AMPK) signaling. The enhanced glucose uptake by CKE were abolished by treatment with bisphenol a diglycidyl ether (BADGE), a PPARγ antagonist, or LY294002, an inhibitor of phosphoinositide 3-kinase (PI3K), but not by compound C, an AMPK inhibitor.

Conclusion

Consistent with the high PPARγ ligand-binding activity, CKE increased glucose uptake through PPARγ activation and insulin signaling. These results suggest that CKE could have pharmacological effects for the treatment of hyperglycemia and type 2 diabetes.     

梓醇和小檗碱及其配伍对脂肪细胞糖代谢和分化的影响

目的:观察中药提取物梓醇和小檗碱及其配伍对3T3-L1脂肪细胞增殖,葡萄糖代谢及细胞分化的影响,初步探讨药物改善胰岛素抵抗(IR)的可能机制。方法:采用四甲基偶氮唑盐(MTT)方法检测3T3-L1前脂肪细胞的增殖;以葡萄糖氧化酶法检测药物干预后培养液中葡萄糖消耗量,并以油红O染色检测细胞分化过程中胞浆脂质的堆积。结果:与对照组比较,小檗碱组使前脂肪细胞MTT值增加29%,而小檗碱加梓醇组、梓醇组均无差异;梓醇、小檗碱及其配伍组分别使成熟脂肪细胞的葡萄糖消耗增加64%、76.5%和98%;小檗碱处理脂肪细胞胞浆脂质堆积明显低于对照组,梓醇组与对照组无差异。结论:小檗碱能促进前脂肪细胞增殖,增加葡萄糖消耗,抑制脂肪细胞分化;梓醇能促进葡萄糖吸收;其作用均不依赖胰岛素的存在。直接增加葡萄糖的吸收可能是这两种药物降低血糖,改善胰岛素抵抗的机制之一。     

苦瓜不同部位对实验性糖尿病小鼠血糖的影响

目的 研究苦瓜不同部位对实验性糖尿病模型小鼠体质量、进食量、进水量和血清中血糖值( GLU)、总胆固醇(TC)、甘油三酯(TG)、超氧化物歧化酶(SOD)、丙二醛(MDA)和游离脂肪酸(NEFA)的影响.方法 雄性昆明种小鼠喂以高脂饲料(10％蛋黄,10％猪油,1％胆固醇,0.2％胆盐,78.8％基料)1个月,诱发胰岛素抵抗,继以腹腔注射低剂量四氧嘧啶(90mg·kg-1),使之产生高血糖症,建立实验性糖尿病小鼠模型.苦瓜水提物冻干粉经100％甲醇回流提取得部位Ⅰ,残渣为部位Ⅱ.分别以10 g·kg-1(相当于生药材重量)的剂量灌胃给药,4周后测定小鼠空腹血糖、糖耐量、血液各项生化指标.结果 苦瓜部位Ⅰ和部位Ⅱ提取物均能缓解由糖尿病所引起的多食多饮病症,降低实验性糖尿病小鼠的GLU、NEFA、TC和MDA值(P＜0.05),升高实验性糖尿病小鼠SOD值(P＜0.05).结论 苦瓜部位Ⅰ和部位Ⅱ提取物能够降低实验性糖尿病小鼠的血糖值,并可调节其血脂代谢,且部位Ⅰ效果更好.