黄芩苷对小肠二糖酶的抑制作用

目的：研究黄芩苷对糖尿病大鼠的降血糖作用及其对大鼠小肠二糖酶的影响。方法：用大鼠小肠刷状缘膜匀浆分析黄芩苷对二糖酶活性的抑制作用;测定黄芩苷对正常小鼠蔗糖负荷糖耐量的影响;观察腹腔注射65mg．kg^-1链脲佐菌素（Streptozotocin,STZ）诱导的糖尿病大鼠用黄芩苷100和200mg.kg^-1治疗4周后,蔗糖负荷糖耐量,实验结束后,分析十二指肠、空肠和回肠黏膜中蔗糖酶的活力。结果：黄芩苷对蔗糖酶活性有抑制作用,对麦芽糖酶活性无抑制作用：正常小鼠灌胃给予黄芩苷后,显著降低蔗糖引起的血糖水平升高。糖尿病大鼠灌胃给予黄芩苷周后,黄芩苷显著降低糖尿病大鼠的血糖水平,减缓糖尿病大鼠体重降低的趋势,同时黄芩苷显著降低糖尿病导致的蔗糖酶活力增强。结论：黄芩苷降低血糖的机制之一可能是抑制小肠蔗糖酶的活性。     

黄连解毒汤调节糖脂代谢的药效学研究

目的:观察黄连解毒汤(HLJDT)对2型糖尿病大鼠血糖、血脂代谢的影响。方法:采用高糖高脂饲料喂养联合链脲佐菌素腹腔注射造成2型糖尿病大鼠模型,造模成功后分HLJDT高、中、低剂量组及二甲双胍组灌胃治疗。治疗56 d后,观察HLJDT各剂量组对模型大鼠血糖指标空腹血糖(FBG)、胰岛素(Ins),血脂指标总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)代谢的影响。结果:黄连解毒汤不仅可以降低糖尿病模型大鼠血清中FBG、TC、TG、LDL-C含量,而且可以提高血清Ins、HDL-C含量。结论:黄连解毒汤能够有效调节糖尿病大鼠的血糖、血脂水平。     

黄连解毒汤对体内外晚期糖基化终产物形成的影响

目的探讨黄连解毒汤对体内外晚期糖基化终产物(AGEs)形成的影响。方法链脲佐菌素(ip给药)建立糖尿病大鼠模型,以不同剂量(0.5、1.0 g/kg)黄连解毒汤ig给药90 d后,检测血糖、糖化血红蛋白,血浆和肾组织中的果糖胺和AGEs水平。将不同浓度的黄连解毒汤与葡萄糖和牛血清白蛋白孵育21 d,用荧光光度法测定AGEs的荧光值。结果黄连解毒汤能明显降低糖尿病大鼠的血糖和糖化血红蛋白水平(P<0.01),抑制血浆和肾组织的果糖胺和AGEs的生成(P<0.01),并呈明显的剂量依赖性。黄连解毒汤对体外AGEs的生成也有明显的抑制作用,并有一定的剂量依赖性。结论黄连解毒汤对体内外AGEs的生成均有明显的抑制作用,这可能是黄连解毒汤治疗糖尿病并发症的机制之一。     

蒲公英水提取物对链脲佐菌素致糖尿病大鼠的降血糖作用及其机制

目的 研究蒲公英水提取物降低链脲佐菌素(STZ)致糖尿病大鼠餐后血糖水平的作用及其机制.方法 考察蒲公英水提取物400、200、100 mg/kg对STZ致糖尿病模型大鼠餐后血糖水平的影响,并采用ELISA法检测各组大鼠血清胰岛素水平;正糖钳实验考察蒲公英水提取物对正常大鼠胰岛素敏感性的影响,检测葡萄糖输注率(GIR);以pNPG为底物,测定蒲公英水提取物400 mg/kg体外对α-糖苷酶活性的影响;采用Caco-2细胞单层模拟的小肠上皮模型,评价蒲公英水提取物200、100 mg/L对小肠麦芽糖水解和葡萄糖吸收能力的影响.结果 蒲公英水提取物400、200、100 mg/kg给药7d,可显著降低正常大鼠及STZ致糖尿病大鼠餐后血糖水平,但对血清胰岛素水平、GIR均无影响.蒲公英水提取物对α-糖苷酶活性具有抑制作用,但半数抑制浓度(IC50)高于阳性药阿卡波糖;蒲公英水提取物200 mg/L可同时抑制Caco-2细胞单层对麦芽糖的水解和对葡萄糖的转运.结论 蒲公英水提取物具有降低餐后血糖的作用,其作用机制与抑制小肠对麦芽糖的水解和对葡萄糖的吸收有关.     

胰岛素油相制剂给药方法和作用机制的研究

 目的通过比较胰岛素油相制剂口服给药和肠道给药的降血糖作用,以及胰岛素油相制剂经小肠灌流后肝门静脉和肝静脉的血胰岛素水平,研究胰岛素油相制剂的合适给药方法与作用机制。方法采用专利方法制备胰岛素油相制剂。糖尿病大鼠分别口服和十二指肠注入胰岛素油相制剂后测定血糖,正常大鼠小肠灌流胰岛素油相制剂后用RIA方法测定肝门静脉和肝静脉血液中胰岛素。结果糖尿病大鼠实验显示,当肠道用药量是口服用药量的1/3时,肠道给药比口服给药降血糖AUC_0-6h提高67%,两者相比有显著性差异(P<0.05)。小肠灌流实验显示,肝门静脉胰岛素浓度显著高于肝静脉胰岛素浓度(P<0.05),胰岛素油相制剂透过小肠上皮细胞的能力显著高于胰岛素水溶液(P<0.05)。同时血糖浓度与肝门静脉和肝静脉中的胰岛素浓度差值显示了很好的负相关关系。结论该油相制剂能有效保护胰岛素的活性。肠道给药比口服给药用药剂量低,降血糖效果好。小肠灌流实验表明,油相制剂中的胰岛素经过肝脏时主要因首过效应而发挥生物学作用。该油相制剂的合适剂型为肠溶胶丸。     

酸角壳提取物对蔗糖负荷大鼠血糖及α-葡萄糖苷酶和α-淀粉酶的影响

目的研究酸角壳提取物对蔗糖负荷大鼠糖吸收的抑制作用。方法采用蔗糖负荷大鼠模型观察酸角壳提取物对蔗糖负荷后不同时间点血糖的影响;采用酶标法测定酸角壳提取物对正常大鼠肠黏膜和内容物中α-葡萄糖苷酶和α-淀粉酶活性的影响,评价酸角壳提取物对肠道α-葡萄糖苷酶和α-淀粉酶活性的影响。结果各剂量酸角壳提取物能显著降低蔗糖负荷后15分钟大鼠的血糖水平(P0.01)。酸角壳提取物能明显抑制小肠上段和中段α-葡萄糖苷酶以及小肠中段α-淀粉酶的活性,在给药30分钟到1小时的抑制作用最为显著。结论酸角壳提取物能够显著降低蔗糖负荷后大鼠的血糖水平,其作用可能与抑制肠道α-葡萄糖苷酶和α-淀粉酶活性有关。     

黄连解毒汤对糖尿病大鼠脂肪因子visfatin表达的影响

目的 :研究黄连解毒汤对糖尿病大鼠肝脏visfatin表达的影响,探讨黄连解毒汤改善胰岛素抵抗的作用机制。方法 :实验采用高脂高糖饮食联合链脲佐菌素(STZ)复制糖尿病大鼠模型,分为空白组、模型组、对照组、治疗组,连续给药6周后测空腹血糖(FBG)、空腹胰岛素(FINS)、总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)含量及肝脏visfatin表达的变化。结果:治疗组血清FBG、FINS、TC、TG、LDL-C水平显著低于模型组(P0.01),HDL-C水平高于模型组(P0.01);治疗组肝脏表达visfatin显著低于模型组(P0.01)。结论:黄连解毒汤能显著降低糖尿病大鼠血脂血糖,改善胰岛素抵抗,其机制可能是调节脂肪因子visfatin的表达,降低炎症信号通路,改善脂肪组织的慢性炎症反应。     

黄连解毒汤及桂枝汤对GK大鼠心肌Ⅰ、Ⅲ型胶原表达的影响

目的:探索黄连解毒汤、桂枝汤对自发性糖尿病(GK)大鼠心肌胶原重构的影响。方法:实验大鼠随机分为GK对照组、二甲双胍组、桂枝汤组、黄连解毒汤组,另设正常对照组,测定血糖,免疫组化方法检测各组Ⅰ型胶原、Ⅲ型胶原阳性面密度。结果:GK大鼠血糖明显升高,胶原Ⅰ型阳性面密度比值升高,胶原Ⅲ型阳性面密度比值下降(P<0.01)。黄连解毒汤组、二甲双胍组血糖下降(P<0.01);黄连解毒汤和桂枝汤胶原Ⅰ型阳性面密度降低(P<0.05,两方剂之间P>0.05)),二甲双胍组升高(P>0.05);黄连解毒汤和桂枝汤胶原Ⅲ型阳性面密度升高(P<0.05,P<0.01),二甲双胍组也升高(P>0.05),桂枝汤组升高程度较大,优于黄连解毒汤、二甲双胍组(P<0.05)。结论:黄连解毒汤对GK大鼠有降低血糖作用。两方剂均能抑制胶原Ⅰ型阳性表达,促进胶原Ⅲ型阳性表达。在促进胶原Ⅲ型阳性表达方面,桂枝汤优于黄连解毒汤。     

黄连解毒汤对糖尿病大鼠肝脏核因子-κB、肿瘤坏死因子-α表达的影响

目的:研究黄连解毒汤对糖尿病大鼠肝脏核转录因子-κB(NF-κB),肿瘤坏死因子-α(TNF-α)表达的影响,探讨黄连解毒汤治疗糖尿病的机制。方法:实验采用高脂饮食加小剂量链脲佐菌素(STZ)复制大鼠糖尿病模型,连续给黄连解毒汤(11.5,5.7,2.85 g.kg-1)8周后测定空腹血糖(FGB)、总胆固醇(CHO)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDLC)、高密度脂蛋白胆固醇(HDLC)含量,同时计算肝脏和胰腺质量指数;采用免疫组织化学的方法检测大鼠肝脏中NF-κB,TNF-α含量。结果:黄连解毒汤高剂量组能显著降低大鼠血清中CHO,TG,LDLC含量,各剂量组均升高HDLC含量,明显降低胰腺的质量指数;大鼠肝脏NF-κB,TNF-α的表达明显低于模型组。结论:黄连解毒汤对高脂饮食加小剂量STZ所致糖尿病大鼠有一定的治疗作用,其机制可能是通过调节NF-κB,TNF-α蛋白的表达,从而抑制了炎症信号的通路。     

黄连解毒汤对脑梗塞急性期大鼠胃肠动力的调节作用

目的:研究黄连解毒汤对脑梗塞急性期大鼠胃动素(MTL)及血管活性肠肽(VIP)的影响。方法:制备大鼠大脑中动脉梗塞模型,随机分为脑梗塞组、黄连解毒汤常规剂量组、黄连解毒汤高剂量组、西咪替丁组、假手术组,并设正常对照组。分别给予生理盐水、黄连解毒汤常规剂量、黄连解毒汤高剂量、西咪替丁、生理盐水灌胃,分别于4、7天后测定血浆胃动素、血管活性肠肽含量。结果:脑梗塞大鼠4天、7天时MTL、VIP含量较相应正常组、假手术组均有升高(P0.01),黄连解离汤高剂量组MTL、VIP较模型组明显降低。4天时与黄连解毒汤常规剂量组相比,黄连解毒汤高剂量组MTL水平具有显著统计学差异(P0.01),而VIP水平也具有统计学意义(P0.05);黄连解毒汤常规7天组MTL、VIP含量较4天组降低(P0.05)。结论:黄连解毒汤能有效调节脑梗塞急性期大鼠胃动素及血管活性肠肽的表达,且疗效与剂量有关。     

Antihyperglycemic effect of the traditional Chinese scutellaria–coptis herb couple and its main components in streptozotocin-induced diabetic rats

Ethnopharmacological relevance

Scutellaria–coptis herb couple (SC) is the main herb couple in many traditional Chinese compound formulas used for the treatment of diabetes mellitus, which has been used to treat diabetes mellitus for thousands of years in China. In this study we provide experimental evidence for the clinical use of SC in the treatment of diabetes mellitus.

Aim of the study

To confirm the anti-diabetic effect of SC extract and its main components, and to explore its mechanism from the effect on intestinal disaccharidases by in vivo and in vitro experiment.

Materials and methods

SC extract was prepared and the main components (namely berberine and baicalin) contained in the extract were assayed with high performance liquid chromatography (HPLC). And diabetic model rats were induced by intraperitoneal injection of streptozotocin (STZ). After grouped randomly, diabetic rats were administered SC extract, berberine, baicalin, berberine+baicalin, acarbose and vehicle for 33 d, respectively. Body weight, food intake, urine volume, urine sugars, fasting plasma glucose and fasting plasma insulin were monitored to evaluate the antidiabetic effects on diabetic rats. Intestinal mucosa homogenate was prepared and the activities of intestinal disaccharidases were assayed. Moreover, oral sucrose tolerance test (OSTT) was performed and the inhibitory effects of SC extract and its main components (berberine and baicalin) on the maltase and sucrase in vitro was evaluated.

Results

After the treatment of SC extract and its main components, the body weight and the fasting plasma insulin level were found to be increased while food intake, urine volume, urine sugars and fasting plasma were decreased. OSTT showed that SC extract and its main components could lower the postprandial plasma glucose level of diabetic rats. Furthermore, SC extract and its main components could inhibit the activities of intestinal disaccharidases in diabetic rats, whereas only SC extract and berberine could inhibit the activity of maltase in vitro.

Conclusions

According to our present findings, scutellaria–coptis herb couple (SC) possessed potent anti-hyperglycemic effect on STZ-induced diabetic rats. And SC extract and its main components exerted anti-hyperglycemic effect partly via inhibiting the increased activities of intestinal disaccharidases and elevating the level of plasma insulin in diabetic rats induced by STZ.     

Effect of Luffa aegyptiaca (seeds) and Carissa edulis (leaves) extracts on blood glucose level of normal and streptozotocin diabetic rats

The present study investigates the effect of oral administration of the ethanolic extracts of Luffa aegyptiaca (seeds) and Carissa edulis (leaves) on blood glucose levels both in normal and streptozotocin (STZ) diabetic rats. Treatment with both extracts significantly reduced the blood glucose level in STZ diabetic rats during the first three hours of treatment. L. aegyptiaca extract decreased blood glucose level with a potency similar to that of the biguanide, metformin. The total glycaemic areas were 589.61 ± 45.62 mg/dl/3 h and 660.38 ± 64.44 mg/dl/3 h for L. aegyptiaca and metformin, respectively, vs. 816.73 ± 43.21 mg/dl/3 h for the control (P < 0.05). On the other hand, in normal rats, both treatments produced insignificant changes in blood glucose levels compared to glibenclamide treatment.     

川芎嗪对糖尿病大鼠视网膜病变IL-1β和ICAM-1表达的影响

目的观察川芎嗪注射液对糖尿病大鼠视网膜病变白细胞介素-1β(IL-1β)和细胞黏附分子-1(ICAM-1)表达的影响,探讨川芎嗪注射液治疗糖尿病大鼠视网膜病变(DR)的作用机制。方法 50只SD大鼠随机分为对照组、模型组和川芎嗪组,用链脲佐菌素(60 mg/kg)一次性腹腔注射的方法建立糖尿病大鼠模型,川芎嗪组予腹腔注射给药川芎嗪(40 mg/kg)。6个月后处死动物摘除眼球进行视网膜血管消化铺片观察和免疫组织化学方法检测IL-1β和ICAM-1的表达。结果造模后模型组视网膜病变明显,川芎嗪治疗后视网膜病变得到明显延缓。视网膜毛细血管IL-1β和ICAM-1的表达,对照组分别为(5.130±1.312)%和(0.424±0.085)%,模型组分别为(7.320±0.623)%和(1.213±0.152)%,川芎嗪组分别为(3.604±1.373)%和(0.614±0.086)%,3组比较均有显著性差异(P均<0.05)。结论川芎嗪可通过降低视网膜IL-1β和ICAM-1的表达,延缓糖尿病大鼠视网膜病变的发生发展。     

Huang-Lian-Jie-Du-Decoction modulates glucagon-like peptide-1 secretion in diabetic rats

Aim of the study

Huang-Lian-Jie-Du-Decoction (HLJDD), a well-known Chinese herbal formula, has been used for diabetic treatment. The purpose of the study was to investigate whether HLJDD affected glucagon-like peptide (GLP)-1 (7–36) amide level in diabetic rats.

Materials and methods

Streptozotocin (STZ)-induced diabetic rats were treated with HLJDD at low dose (2 g/kg/day) or high dose (4 g/kg/day). After 5-week treatment, GLP-1 (7–36) amide level and insulin level in portal vein and tissues stimulated by oral glucose load were measured by ELISA kits. The proglucagon gene expression in intestinal tracts and the proliferation of intestinal L cell and pancreatic beta cell were measured using RT-PCR and immunohistochemistry techniques, respectively.

Results

It was found that 5-week HLJDD treatment attenuated alteration of glucose level and insulin level in plasma and tissues of diabetic rats induced by STZ, accompanied by improvement of diabetic syndrome. 5-week HLJDD treatment increased GLP-1 (7–36) amide level in portal vein plasma and distal ileum. Further studies showed that 5-week HLJDD treatment increased the mRNA level of proglucagon gene in distal ileum, promoted pancreatic beta cell and intestinal L cell proliferation in a dose-dependent manner.

Conclusion

All the results indicated that HLJDD exerted its anti-diabetic effects partly via modulating GLP-1 (7–36) amide level.     

蚕蛹油对糖尿病大鼠血糖和糖代谢相关酶的影响

目的研究蚕蛹油对链脲佐菌素(STZ)诱导的糖尿病大鼠血糖及糖代谢相关酶的影响。方法 SD大鼠以STZ诱导糖尿病模型,大鼠按血糖随机分成6组:模型组,蚕蛹油低、中、高剂量(4.5、6.0、7.5 mL/kg)组,二甲双胍(90 mg/kg)阳性对照组和亚麻籽油(6.0 mL/kg)阳性对照组,另设对照组。各给药组每天ig给药1次,连续4周,对照组和模型组ig生理盐水。每天测大鼠饮食量和饮水量1次,每周末测大鼠体质量和血糖水平,4周后检测大鼠肝脏中己糖激酶(HK)、丙酮酸激酶(PK)以及小肠黏膜中的麦芽糖酶、蔗糖酶、淀粉酶的活性,并进行淀粉耐量检测。结果蚕蛹油各给药组糖尿病大鼠血糖水平呈下降趋势,并呈剂量相关性,HK、PK、麦芽糖酶、蔗糖酶、淀粉酶活性与模型组相比均具有显著差异(P<0.05),且大鼠血糖水平与HK、PK、麦芽糖酶、蔗糖酶、淀粉酶活性的相关性显著(P<0.000 1)。淀粉耐量检测显示,蚕蛹油各给药组大鼠血糖峰值和曲线下面积显著下降(P<0.05)。结论蚕蛹油剂量相关地抑制STZ诱导的大鼠血糖升高,抑制α-葡萄糖苷酶活性,提高HK、PK活性可能是其降血糖作用机制之一。     

绿茶中咖啡因在正常和糖尿病认知功能障碍大鼠体内的药代动力学及药效学分析

目的:在建立气相色谱法(GC)方法学的基础上,比较绿茶中咖啡因在正常和糖尿病认知功能障碍大鼠体内的血药浓度,并验证其对糖尿病认知功能障碍的影响。方法:采用链脲佐菌素(STZ)一次性腹腔注射(剂量50 mg·kg-1)复制糖尿病模型,模型复制成功后灌胃咖啡因和绿茶浸出液进行干预,并且每3周测定1次血糖值,诱导第12周时Morris水迷宫试验检测认知功能,选择HP-5色谱柱,二阶升温程序,流速1.0 m L·min-1,分流比10∶1,氢火焰离子化检测器(FID),检测器温度和进样口温度均为250℃,载气为氮气的色谱条件进行咖啡因在正常和糖尿病认知功能障碍大鼠体内的药代动力学研究,运用透射电镜观察神经元细胞的超微结构。结果:咖啡因的线性范围1.28~128 mg·L-1(R2=0.998),最低检测限和最低定量限分别为0.7,1.28 mg·L-1,日内和日间精密度均8.0%,提取回收率和方法回收率均90%。咖啡因在正常和糖尿病认知功能障碍大鼠体内的药时曲线下面积(AUC0-t)分别为(46.71±4.25),(61.2±5.44)mg·h·L-1,半衰期(t1/2)分别为(2.82±0.38),(3.71±0.13)h,药峰浓度(Cmax)分别为(13.25±2.02),(17.12±1.08)mg·L-1,清除率(CL)分别为(0.43±0.08),(0.33±0.07)L·kg-1·h-1。与模型组比较,咖啡因组和绿茶组血糖下降、认知能力和神经元细胞超微结构得到改善。结论:咖啡因在正常和糖尿病认知功能障碍大鼠体内的代谢存在差异,且具有改善糖尿病认知功能障碍的功效,这为绿茶和咖啡因临床用于防止糖尿病认知障碍提供了一定理论依据。     

龙须草水煎液对糖尿病大鼠血糖和胰岛素水平的影响

目的:探讨龙须草水煎液对糖尿病大鼠血糖和胰岛素水平的影响.方法:大鼠以高脂饲料喂养1个月诱导加1次性ip链脲佐菌素制造2型糖尿病模型,将Wistar雄性大鼠随机分成6组:正常对照组、模型组、二甲双胍(0.15 g·kg-1·d-1),龙须草水煎液低、中、高剂量组(2.5,5,10 g·kg-1·d-1),口服给药30 d,并在相应时间采血测定空腹血糖(FBG)、糖耐量2h血糖、空腹胰岛素(FINS).结果:龙须草水煎液中、高剂量给药30 d糖尿病大鼠FBG分别为(14.30 ±3.04),(13.25±3.81)mmol·L-1低于模型组(P＜0.01);大鼠糖耐量分别为(13.44 ±3.24),(13.03±4.72) mmol·L-1低于模型组(P＜0.05);血清胰岛素水平分别为(15.40±3.76),(16.39±4.75)mU·L-1高于模型组(P＜0.01).结论:龙须草水煎液对高血糖模型大鼠具降低血糖和升高胰岛素水平的作用.     

Study of the hypoglycaemic activity of Fraxinus excelsior and Silybum marianum in an animal model of type 1 diabetes mellitus

The hypoglycaemic effect of the aqueous extracts of Fraxinus excelsior (FE) seed and Silybum marianum (SM) aerial part was investigated in normal and streptozotocin (STZ) diabetic rats. After a single dose or 15 daily doses, oral administration of the aqueous extracts (20 mg/kg) produced a significant decrease of blood glucose levels in both normal and STZ diabetic rats (P < 0.001). From the first week, the body weight was increased in normal rats (P < 0.05) and decreased in STZ rats (P < 0.01) after FE administration. In addition, no changes were observed in basal plasma insulin concentrations after both FE and SM treatments in either normal and STZ diabetic rats indicating that these plants exert their pharmacological activity without affecting insulin secretion. We conclude that the aqueous extracts of FE and SM exhibit potent hypoglycaemic and anti-hyperglycaemic activities in normal and STZ rats, respectively, without affecting basal plasma insulin concentrations.     

葛根多糖对2型糖尿病大鼠的治疗作用及机制研究

[目的]研究葛根多糖对2型糖尿病大鼠的治疗作用及作用机制。[方法]采用腹腔注射链脲佐菌素(STZ)联合高脂饮食饲养诱导2型糖尿病大鼠模型,给予不同剂量的葛根多糖,通过检查体质量变化、空腹血糖含量、胰岛素水平、葡萄糖耐受能力、总胆固醇和甘油三酯等指标,观察其对大鼠模型的治疗作用,同时测定葛根多糖对各组动物肝脏组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛(MDA)水平的影响,初步评价其抗氧化作用。[结果]葛根多糖可以有效改善2型糖尿病大鼠的相关生化指标,同时可以提升肝脏组织中SOD、CAT水平、降低MDA水平。[结论]葛根多糖具有降血糖和降血脂作用,可能与其抗氧化作用有关。