艾塞那肽改善T2DM患者和db/db小鼠肝脏胰岛素抵抗的作用

目的： 探讨艾塞那肽对肝胰岛素抵抗（IR）的作用。方法：选取2017年8月 ~ 2020年8月连续使用艾塞那肽治疗6个月的80例T2DM患者,检测患者用药前后糖化血红蛋白（HbA1c）、空腹血糖（FPG）等指标,计算体质量指数（BMI）、稳态模型胰岛素抵抗指数（HOMA-IR）与稳态模型胰岛功能（HOMA-β）。以db/db小鼠为糖尿病研究模型,艾塞那肽连续治疗8周,进行葡萄糖耐受（OGTT）和胰岛素耐受（ITT）试验,测定FPG和胰岛素水平;肝脏切片进行HE和PAS染色。结果：艾塞那肽治疗后,T2DM患者HbA1c、FPG、HOMA-IR水平明显降低（P ＜ 0.05）;艾塞那肽增加HepG2细胞IR模型的萄萄糖消耗量（P ＜ 0.05）;艾塞那肽降低db/db小鼠FPG、空腹血清胰岛素、HOMA-IR,胰岛素敏感性增加,肝糖原累积面积增加（P ＜ 0.05）。结论：艾塞那肽可显著改善肝胰岛素抵抗。     

牛蒡子苷对自发型糖尿病db/db小鼠降血糖作用的实验研究

目的：观察牛蒡子苷对db/db自发型糖尿病小鼠的降血糖作用及其潜在的作用机制。方法：40只db/db小鼠随机分为5组：模型对照组,牛蒡子苷75,150,300 mg·kg^-1组和二甲双胍300 mg·kg^-1组,同时设置db/m小鼠空白对照组,灌胃给予相应药物或溶媒,连续4周。给药3周后,进行口服糖耐量试验。4周给药结束后,小鼠禁食12 h,称体质量,检测空腹血糖值（FBG）,处死动物,取血清,检测胰岛素（INS）、糖化血清蛋白（GSP）、三酰甘油（TG）、总胆固醇（TC）和脂联素（APN）含量。结果：与模型对照组比较,牛蒡子苷中、高剂量能显著降低db/db小鼠FBG、INS、GSP、TG、TC和APN的血清浓度,改善小鼠糖耐量（P〈0.05或0.01）。结论：牛蒡子苷能显著改善db/db小鼠糖脂代紊乱,减轻胰岛素抵抗,其作用机制可能与上调脂联素表达有关。     

滋阴益气活血泄浊法对db／db小鼠糖代谢的影响

目的：探讨滋阴益气活血泄浊法对db／db小鼠整体水平糖代谢的影响。方法选取12~14周龄雄性db／db小鼠,按空腹血糖及体质量随机分成模型组、阿卡波糖组、石斛合剂序贯组（以下简称序贯组）;选db／m为正常对照组。连续灌胃给药共6个循环（42d）。治疗前测各药物对淀粉耐量影响。每2周期测空腹血糖（FBG）,实验结束前测口服葡萄糖耐量（OGTT）和测定糖化血清蛋白（GSP）、血清胰岛素（Ins）以及各药物干预后的肠上皮α-葡萄糖苷酶活性。结果石斛合剂1方和2方单次给药均能明显降低db／db小鼠淀粉耐量30,60,120min血糖;随治疗循环数增加,序贯组的FBG逐步下降;与模型组比较,序贯组FBG、GSP和Ins显著下降（P<0.05）,改善葡萄糖耐量;石斛合剂1方、2方降低肠上皮α-葡萄糖苷酶活性（P<0.05）。结论石斛合剂有明确的α-葡萄糖苷酶抑制作用,序贯治疗能降低db／db小鼠的血糖相关指标,降低高胰岛素血症,表明滋阴益气活血泄浊法的降糖机制可能与抑制α-葡萄糖苷酶活性有关。     

艾塞那肽类似物的制备及降糖活性

针对艾塞那肽序列中易氧化的氨基酸,设计了EB1、EB2、EB3三种序列;采用Fmoc固相合成法对其进行合成,纯化后进行了活性、稳定性的研究.结果显示3种类似物都有较高的纯化收率,降糖活性与艾塞那肽相当,抗DPP-Ⅳ酶稳定性均较好,抗氧化能力明显提高,为新型糖尿病药物的开发打下基础.     

利福平聚乳酸-羟基乙酸共聚物纳米粒雾化吸入给药肺靶向性研究

目的研究利福平聚乳酸-羟基乙酸共聚物纳米粒雾化吸入给药的肺靶向性。方法分别将利福平聚乳酸-羟基乙酸共聚物纳米粒混悬液(RFP-PLGA-NPs)和利福平注射液(RFP-Sol)以雾化吸入方式给予SD大鼠,在不同时间点测定利福平在大鼠肺组织中的浓度,计算相应药动学参数,比较2种制剂在肺组织中药动学过程,并评价靶向性。结果 RFP-Sol和RFP-PLGA-NPs的Tmax分别为(1.50±0.01)h和(2.00±0.08)h,Cmax分别为(0.83±0.07)mg.L 1和(5.02±0.05)mg.L 1,AUC0→∞分别为(6.24±0.24)mg.h.L 1和(35.80±6.34)mg.h.L 1,CL分别为(4.801±0.18)L.h 1.kg 1和(0.85±0.15)L.h 1.kg 1。通过对re和Ce等靶向性指标进行分析,RFP-PLGA-NPs在肺组织中的re和Ce均>1。结论与RFP-Sol相比,RFP-PLGA-NPs经雾化吸入给药后,明显提高了肺组织中药物的分布并且延缓消除,有显著的缓释性,从而降低药物对全身的不良反应,提高对肺结核的治疗作用。     

Developmental Toxicity Study of Glycolic Acid in Rats

ABSTRACT

The developmental toxicity of glycolic acid was assessed in rats by orally administering solutions of the test material in water over days 7-21 of gestation (the day of copulation plug detection was defined as day 1 of gestation). Groups of 25 mated female Crl:CD®BR rats were gavaged at daily dose levels of 0, 75, 150, 300 or 600 mg/kg. The dams were euthanized on day 22 and the offspring were weighed, sexed, and examined for external, visceral, and skeletal alterations. Clear evidence of maternal toxicity was demonstrated at 600 mg/kg; adverse clinical observations were statistically significantly increased (wheezing/lung noise, abnormal gait/staggering, lethargy). in addition, maternal body weights, weight changes, and food consumption were statistically significantly reduced at this dose level. Marginal evidence of maternal toxicity was demonstrated at 300 mg/kg; wheezing/lung noise similar to that seen at 600 mg/kg was observed in 2 of 25 dams. This increase approached statistical significance (p=0.0553). There was marked evidence of developmental toxicity at 600 mg/kg. Mean fetal weight was statistically significantly reduced while the incidences of skeletal (ribs, vertebra, and sternebra) malformations and variations were statistically significantly increased. At 300 mg/kg/day, there was a slight (2 affected fetuses from 2 litters) increase in the incidence of two skeletal malformations: fused ribs and fused vertebra. Although these increases were not statistically significant (p=0.0555), they were consistent with findings seen at 600 mg/kg/day and thus were considered relevant. There was no other evidence of developmental toxicity at 300 mg/kg/day nor was any developmental toxicity seen at 150 or 75 mg/kg/day. Thus, the maternal and developmental no-observed-effect level (NOEL) was considered 150 mg/kg.     

山奈酚通过抑制NLRP3炎症小体介导的脂肪组织炎症改善db/db小鼠胰岛素抵抗发生

目的：探讨山奈酚能否通过调控肥胖小鼠脂肪组织炎症改善胰岛素抵抗发生并研究作用机制。方法：db/m小鼠作为对照组,db/db雄性小鼠随机分为模型组、二甲双胍组(0.15 g·kg^-1·d^-1)和山奈酚组(50 mg·kg^-1·d^-1)。连续灌胃给药6周,每周记录小鼠体重,6周后进行葡萄糖耐量试验、胰岛素耐量试验、皮下和附睾白色脂肪组织质量测定;HE染色观察脂肪组织形态学变化,免疫组化法观察巨噬细胞向脂肪组织的浸润程度及巨噬细胞标志物F4/80的表达,实时荧光定量PCR检测TNF-α和IL-18以及Arg-1和IL-10的mRNA表达,蛋白质免疫印迹试验检测NLRP3、pro-caspase1、cle-caspase1和IL-1β表达。结果：与模型组相比,山奈酚能够显著抑制db/db小鼠脂肪质量增加,抑制脂肪细胞肥大。山奈酚组小鼠脂肪组织巨噬细胞浸润减少,TNF-α和IL-18 mRNA表达减少,Arg-1和IL-10 mRNA表达增加;山奈酚治疗能够抑制小鼠附睾脂肪组织NLRP3、caspase1以及...     

重组人胰岛素样生长因子-1对db/db小鼠应激性血糖升高的保护作用

目的:研究重组人胰岛素样生长因子(rhIGF)-1对2型糖尿病(T2DM)伴胰岛素抵抗(IR)小鼠应激性血糖升高的治疗作用。方法:以瘦素受体基因缺陷型db/db小鼠为动物模型,电脉冲刺激诱发应激性高血糖。给予高剂量胰岛素或rhIGF-1进行干预,观察血糖的变化情况。Real time-PCR及Western blot分别检测骨骼肌组织内GLUT4基因的表达水平及GLUT4蛋白含量。结果:在8周龄时瘦素受体基因缺陷的db/db小鼠表现出了明显的肥胖、高血糖及高胰岛素血症。应激后组间血糖水平的差异有统计学意义(F组间=48.915,P<0.05),组内不同时间点血糖水平差异无统计学意义(F时间=1.295,P>0.05),组间和时间无交互效应(F交互=1.046,P>0.05)。采取干预措施后,组间血糖水平差异有统计学意义(F组间=36.947,P<0.05),不同时间点血糖水平差异有统计学意义(F时间=13.880,P<0.05),且组间和时间存在交互效应(F交互=11.769,P<0.05)。IGF-1可显著增加db/db小鼠骨骼肌组织中GLUT4基因的表达及GLUT4蛋白在细胞膜中的含量。结论:rhIGF-1对T2DM小鼠被诱发的应激性高血糖具有较胰岛素更好的控制作用,此作用可能是因骨骼肌细胞中GLUT4的表达及转位增加所致。     

HPLC法测定注射用艾塞那肽中主药的含量

目的:建立测定注射用艾塞那肽中主药含量的高效液相色谱法.方法:色谱柱为Agilent ZORBAX SB-C3,流动相A相为20 mmol/L磷酸二氢钾(磷酸调pH至3.0),B相为乙腈,梯度洗脱,流速为1.2 ml/min,检测波长为210 nm,进样量为100μl.结果:艾塞那肽的线性范围为5～50 μg/ml(r=0.999 9),平均加样回收率为100%(RSD=0.70%),有关物质总量为3.33%.结论:本方法简便、快速、准确,适用于该制剂的质量控制.     

Anti-Cancer,Anti-Diabetic and Other Pharmacologic and Biological Activities of Penta-Galloyl-Glucose

1, 2, 3, 4, 6-penta-O-galloyl-β-D-glucose (PGG) is a polyphenolic compound highly enriched in a number of medicinal herbals. Several in vitro and a handful of in vivo studies have shown that PGG exhibits multiple biological activities which implicate a great potential for PGG in the therapy and prevention of several major diseases including cancer and diabetes. Chemically and functionally, PGG appears to be distinct from its constituent gallic acid or tea polyphenols. For anti-cancer activity, three published in vivo preclinical cancer model studies with PGG support promising efficacy to selectively inhibit malignancy without host toxicity. Potential mechanisms include anti-angiogenesis; anti-proliferative actions through inhibition of DNA replicative synthesis, S-phase arrest, and G₁ arrest; induction of apoptosis; anti-inflammation; and anti-oxidation. Putative molecular targets include p53, Stat3, Cox-2, VEGFR1, AP-1, SP-1, Nrf-2, and MMP-9. For anti-diabetic activity, PGG and analogues appear to improve glucose uptake. However, very little is known about the absorption, pharmacokinetics, and metabolism of PGG, or its toxicity profile. The lack of a large quantity of highly pure PGG has been a bottleneck limiting in vivo validation of cancer preventive and therapeutic efficacies in clinically relevant models.     

重组人胰岛素样生长因子1对db／db小鼠血糖的影响

目的:研究重组人胰岛素样生长因子1(rhIGF-1)对近似于人类2型糖尿病的db/db小鼠的降血糖作用.方法:正常饲养db/db及同品系的正常小鼠,定期监测血糖和血胰岛素水平.待db/db小鼠表现出明显的高血糖及高胰岛素血症后随机分为4组,每日皮下注射溶媒、胰岛素或不同剂量的rhlGF-1,共2周.首次给药后每30min测定血糖1次,观测不同干预方式的即时降糖效果.再于每次给药前测定血糖,观察2周内的变化趋势.结果:db/db小鼠饲养至8周龄时表现出明显的血糖升高及高胰岛素血症.所用剂量的胰岛素对db/db小鼠未表现出明显的降血糖作用;rhIGF-1特别是高剂量rhIGF-1即时及短期降糖效果均较明显,可有效保护db/db小鼠.结论:rhIGF-1对db/db小鼠有较好的降血糖作用,对伴有明显胰岛素抵抗的糖尿病患者具有临床应用前景.     

Dioscorea Extract (DA-9801) Modulates Markers of Peripheral Neuropathy in Type 2 Diabetic db/db Mice

The purpose of this study was to investigate the therapeutic effects of DA-9801, an optimized extract of Dioscorea species, on diabetic peripheral neuropathy in a type 2 diabetic animal model. In this study, db/db mice were treated with DA-9801 (30 and 100 mg/kg, daily, p.o.) for 12 weeks. DA-9801 reduced the blood glucose levels and increased the withdrawal latencies in hot plate tests. Moreover, it prevented nerve damage based on increased nerve conduction velocity and ultrastructural changes. Decrease of nerve growth factor (NGF) may have a detrimental effect on diabetic neuropathy. We previously reported NGF regulatory properties of the Dioscorea genus. In this study, DA-9801 induced NGF production in rat primary astrocytes. In addition, it increased NGF levels in the sciatic nerve and the plasma of type 2 diabetic animals. DA-9801 also increased neurite outgrowth and mRNA expression of Tieg1/Klf10, an NGF target gene, in PC12 cells. These results demonstrated the attenuation of diabetic peripheral neuropathy by oral treatment with DA-9801 via NGF regulation. DA-9801 is currently being evaluated in a phase II clinical study.     

Improvement of mechanical heart function by trimetazidine in db/db mice

Aim:

To investigate the influence of trimetazidine, which is known to be an antioxidant and modulator of metabolism, on cardiac function and the development of diabetic cardiomyopathy in db/db mouse.

Methods:

Trimetazidine was administered to db/db mice for eight weeks. Cardiac function was measured by inserting a Millar catheter into the left ventricle, and oxidative stress and AMP-activated protein kinase (AMPK) activity in the myocardium were evaluated.

Results:

Untreated db/db mice exhibited a significant decrease in cardiac function compared to normal C57 mice. Oxidative stress and lipid deposition were markedly increased in the myocardium, concomitant with inactivation of AMPK and increased expression of peroxisome proliferator-activated receptor coactivator-1α (PGC-1α). Trimetazidine significantly improved systolic and diastolic function in hearts of db/db mice and led to reduced production of reactive oxygen species and deposition of fatty acid in cardiomyocytes. Trimetazidine also caused AMPK activation and reduced PGC-1α expression in the hearts of db/db mice.

Conclusion:

The data suggest that trimetazidine significantly improves cardiac function in db/db mice by attenuating lipotoxicity and improving the oxidation status of the heart. Activation of AMPK and decreased expression of PGC-1α were involved in this process. Furthermore, our study suggests that trimetazidine suppresses the development of diabetic cardiomyopathy, which warrants further clinical investigation.     

Berberine Improves the Protective Effects of Metformin on Diabetic Nephropathy in db/db Mice through Trib1-dependent Inhibiting Inflammation

Pharmaceutical Research - Diabetic nephropathy (DN), one of severe diabetic complications in the diabetes, is the main cause of end stage renal disease (ESRD). Notably, the currently available...     

Comparison of gene expression changes induced by biguanides in db/db mice liver

Large-scale clinical studies have shown that the biguanide drug metformin, widely used for type 2 diabetes, to be very safe. By contrast, another biguanide, phenformin, has been withdrawn from major markets because of a high incidence of serious adverse effects. The difference in mode of action between the two biguanides remains unclear. To gain insight into the different modes of action of the two drugs, we performed global gene expression profiling using the livers of obese diabetic db/db mice after a single administration of phenformin or metformin at levels sufficient to cause a significant reduction in blood glucose level. Metformin induced modest expression changes, including G6pc in the liver as previously reported. By contrast, phenformin caused changes in expression level of many additional genes. We used a knowledge-based bioinformatic analysis to study the effects of phenformin. Differentially expressed genes identified in this study constitute a large gene network, which may be related to cell death, inflammation or wound response. Our results suggest that the two biguanides show a similar hypoglycemic effect in db/db mice, but phenformin induces a greater stress on the liver even a short time after a single administration. These findings provide a novel insight into the cause of the relatively high occurrence of serious adverse effect after phenformin treatment.     

Hepatic metabolism of sulfur amino acids in db/db mice

To determine the effect of type-2 diabetes and obesity on the hepatic metabolism of sulfur amino acids, hepatic sulfur amino acid metabolism was determined in db/db mice. Hepatic methionine was markedly decreased in db/db mice, although the hepatic activity of betaine homocysteine methyltransferase was increased. The decrease in hepatic methionine was reflected by decreased sulfur-containing methionine metabolites, including S-adenosylmethionine, homocysteine, cysteine, and hypotaurine in liver and plasma. In contrast, S-adenosylhomocysteine, putrescine, and spermidine were increased in db/db mice. The hepatic level and activity of methionine adenosyltransferase I/III, an S-adenosylmethionine synthesizing enzyme, were significantly increased. These results suggest that increased polyamine synthesis, in conjunction with decreased hepatic methionine levels, is partly responsible for the reduction in hepatic S-adenosylmethionine. Decreased homocysteine in liver and plasma may be attributable to the decrease in hepatic methionine and upregulation of hepatic betaine homocysteine methyltransferase. Glutathione in liver and plasma did not change despite decreased γ-glutamylcysteine ligase activity. The decreased hepatic hypotaurine may be attributable to the downregulation of cysteine dioxygenase. The major finding of this study is that db/db mice exhibited decreases in hepatic methionine and its sulfurcontaining metabolites.     

Analgesic and Antipyretic Activities of n-Butanol Alkaloids Extracted from the Stem Bark Hunteria Zeylanica and its Major Constituent, Strictosidinic Acid, in Mice

The pharmacological activities of the n -butanol alkaloids extracted from the stem bark of Hunteria zeylanica (Retz) Gardn. ex Thw. ( H. zeylanica ) and its major constituent, strictosidinic acid, on nociceptive response using writhing and hot plate tests, the antipyretic activity in yeast-induced fever, pentobarbital-induced sleep, and locomotor activity were examined in mice. Oral administration of H. zeylanica extract at 200 mg/kg significantly decreased the number of contortions and stretchings induced by acetic acid but not heat-induced pain. Strictosidinic acid (5-20 mg/kg, p.o.) also produced a similar effect but less pronounced than the extract. The antipyretic effect of strictosidinic acid (5-20 mg/kg, p.o.) was stronger than that of the extract (100-200 mg/kg, p.o.). The H. zeylanica extract dose-dependently (50-200 mg/kg, p.o.) prolonged the duration of pen-tobarbital-induced sleep but had no sign ificant effect on locomotor activity. No effect of strictosidinic acid was noted on both pentobarbital-induced sleep and locomotor activity. These results suggest that the H. zeylanica extract possesses peripheral analgesic and mild antipyretic effects and its major constituent, strictosidinic acid, exerts a similar analgesic effect with marked antipyretic activity.     

Analgesic and Antipyretic Activities of n-Butanol Alkaloids Extracted from the Stem Bark Hunteria Zeylanica and its Major Constituent,Strictosidinic Acid,in Mice

The pharmacological activities of the n -butanol alkaloids extracted from the stem bark of Hunteria zeylanica (Retz) Gardn. ex Thw. ( H. zeylanica ) and its major constituent, strictosidinic acid, on nociceptive response using writhing and hot plate tests, the antipyretic activity in yeast-induced fever, pentobarbital-induced sleep, and locomotor activity were examined in mice. Oral administration of H. zeylanica extract at 200 mg/kg significantly decreased the number of contortions and stretchings induced by acetic acid but not heat-induced pain. Strictosidinic acid (5–20 mg/kg, p.o.) also produced a similar effect but less pronounced than the extract. The antipyretic effect of strictosidinic acid (5–20 mg/kg, p.o.) was stronger than that of the extract (100–200 mg/kg, p.o.). The H. zeylanica extract dose-dependently (50–200 mg/kg, p.o.) prolonged the duration of pen-tobarbital-induced sleep but had no sign ificant effect on locomotor activity. No effect of strictosidinic acid was noted on both pentobarbital-induced sleep and locomotor activity. These results suggest that the H. zeylanica extract possesses peripheral analgesic and mild antipyretic effects and its major constituent, strictosidinic acid, exerts a similar analgesic effect with marked antipyretic activity.     

Systemic immune modulation induced by alcoholic beverage intake in obese-diabetes (db/db) mice

Alcohol over-consumption is generally immunosuppressive. In this study, the effects of single or repetitive alcohol administration on the systemic immunity of db/db mice were observed to clarify the possible mechanisms for the increased susceptibility of obese individuals to alcohol-related immunological health problems. Alcohol (as a form of commercially available 20% distilled-alcoholic beverage) was orally administered one-time or seven times over 2 weeks to db/db mice and normal C57BL/6J mice. Immunologic alterations were analyzed by observation of body weight and animal activity, along with proportional changes of splenocytes for natural killer cells, macrophages, and T and B lymphocytes. Modulation of plasma cytokine level and immune-related genes were also ascertained by micro-bead assay and a microarray method, respectively. The immune micro-environment of db/db mice was an inflammatory state and adaptive cellular immunity was significantly suppressed. Low-dose alcohol administration reversed the immune response, decreasing inflammatory responses and the increment of adaptive immunity mainly related to CD4⁺ T cells, but not CD8⁺ T cells, to normal background levels. Systemic immune modulation due to alcohol administration in the obese-diabetic mouse model may be useful in the understanding of the induction mechanism, which will aid the development of therapeutics for related secondary diseases.