神秘果及其复合物对四氧嘧啶糖尿病小鼠降血糖作用

通过给小鼠腹腔注射四氧嘧啶建立糖尿病小鼠模型,分别灌胃给予0.2mL/(10g·d)神秘果与神秘果、明月草复合物,连续给药26d,观察其对小鼠体重、空腹血糖等的影响,试验结果:对照组与各剂量组小鼠体重均显著增加,组间小鼠体重无显著差异;与模型对照组相比较,神秘果与神秘果、明月草复合物的低、中、高剂量组均显著降低四氧嘧啶糖尿病小鼠的血糖值,神秘果低、高剂量组降血糖效果接近于降糖药二甲双胍;神秘果与神秘果、明月草复合物降血糖效果与剂量间无剂量效应关系。     

金柑总黄酮对小鼠胃肠吸收功能的影响

以金柑总黄酮为原料,采用阿托品建立抑制胃肠吸收的动物模型,探讨不同产地(湖南浏阳、江西遂川)与不同剂量(160mg/kg、80 mg/kg、20 mg/kg)的金柑总黄酮对小鼠胃排空、小肠推进率和小肠吸收功能的影响.结果表明:与模型对照组比,两个高剂量组的小鼠胃酚红排空、小肠酚红推进率和对木糖的吸收具有极显著的影响(P<0.01),两个中剂量组有显著影响(P<0.05),两个低剂量组无显著影响.     

沙棘果油保肝作用的研究

以河北神兴沙棘研究院提供的沙棘果油配制成受试物,同时按受试物配制比例用蒸馏单甘酯、植物油、蒸馏水配制成溶剂对照液,以小鼠为实验动物,随机分成5组,低、中、高剂量组及肝损伤对照组和溶剂对照组,采取每日经口灌胃,灌胃容量为0.1ml/10g·bw,于试验第40天将各组动物隔夜禁食16h,肝损伤组及各剂量组一次经腹腔注射给予0.15%(V/V)的CCl4油溶液0.1ml/10g·bw,溶剂对照组给予等量经配制好的溶剂,受试物组继续给予受试物至试验结束时,给予CCl424h和48h后处死动物,经肝脏病理学检查结果显示,受试物各剂量组肝伤程度明显轻于肝损伤对照组,经统计学处理,受试各剂量组与肝损伤对照组比较,差异有显著性(P<0.01)。     

蒜头果油对小鼠的急性毒性试验研究

采用昆明种小鼠对蒜头果油进行急性毒性试验。将80只健康小鼠随机分成阴性对照组、食用油组、低剂量组[81. 6g/(kg·bw)]和高剂量组[122. 4g/(kg·bw)]4组,每组雌性和雄性小鼠各半。阴性对照组给药当天和给药后连续观察14d,该组小鼠均未见明显异常。食用油组在给药后第1d表现异常,第2d至第14d都恢复正常。低剂量组和高剂量组小鼠绝大多数在给药后的第1d、第2d表现异常,第3d至第14d恢复正常;其中低剂量组和高剂量组分别有2只和5只小鼠死亡,小鼠的死亡数量有明显的剂量-反应和时间-反应关系。给药小鼠的体重增长幅度无论是雌性还是雄性在给药后的第1d都明显减慢(P0. 01),且高剂量组表现出负增长。在第3d至第14d体重增加变快,甚至有些时段体重增加幅度超过阴性对照组和食用油组,但在整个受试过程中给药小鼠体重总体上都低于阴性对照组和食用油组。表明蒜头果油具有较宽的安全剂量范围,但若在短时间内大量服用可能会导致胃肠系统功能紊乱甚至发生障碍。     

诺丽果粉对四氧嘧啶致糖尿病小鼠的降血糖作用

为观察诺丽果粉对糖尿病小鼠的降糖作用,采用腹腔注射四氧嘧啶建立糖尿病小鼠模型,连续灌胃给药30 d,观察诺丽果粉对小鼠体重、空腹血糖、糖耐量的影响。结果显示,诺丽果粉对正常和模型小鼠的体重无不良影响,对空腹血糖无影响(P0.05);中剂量组小鼠糖耐量实验中的0.5、2 h的血糖值及血糖曲线下面积较模型对照组均显著降低(P0.05),表明诺丽果粉具有辅助降血糖功能。     

接骨木籽油抗氧化、降血糖和降血脂生物活性的研究

采用DPPH清除法和普鲁士蓝法(总还原力)测定接骨木籽油的抗氧化活性。研究结果表明,接骨木籽油具有抗氧化活性,在DPPH清除自由基实验中,接骨木籽油显示出清除自由基的能力,且其清除能力和油脂浓度呈良好线性(R=0.9996)。此外,接骨木籽油清除DPPH自由基的IC_(50)值是61.30±0.88mg/mL。在总还原力测定实验中,接骨木籽油具有还原能力,且其还原能力与油脂浓度呈正比,具有浓度依赖性。通过研究接骨木籽油对α-葡萄糖苷酶的抑制作用,测定接骨木籽油的降血糖活性。主要是通过测定反应体系在400nm下的吸光值判断样品对α-葡萄糖苷酶抑制能力的大小。实验结果表明,接骨木籽油的浓度在1.56~25mg/mL范围内,其有效抑制了α-葡萄糖苷酶,抑制率在62.66%~85.22%。采用动物体内试验测定接骨木籽油的降血脂活性。首先建立高血脂的动物模型,然后通过灌胃给药接骨木籽油,再测定血清中的总胆固醇(TC),甘油三酯(TG),高密度脂蛋白胆固醇(HDL-C),低密度脂蛋白胆固醇(LDL-C)的水平。实验结果表明,接骨木籽油低、中、高剂量3个实验组与高脂模型对照组比较,TC、TG、LDL-C水平极显著(P0.01)降低,HDL-C水平显著升高(P0.05),说明接骨木籽油能有效降低高血脂小鼠血清中的TC、TG、LDL-C的水平,有效抑制HDL-C的水平的降低,所以接骨木籽油可以降低小鼠血脂,故具有降血脂的作用。此外,比较这3个剂量实验组可以发现接骨木籽油剂量越大,小鼠血脂水平下降的效果越明显,说明接骨木籽油的降血脂作用具有剂量依赖性。     

软枣猕猴桃黄酮降血糖作用研究

为探究软枣猕猴桃黄酮的降血糖作用,该研究对小鼠进行高脂高糖饲料喂养和链脲佐菌素注射,建立小鼠Ⅱ型糖尿病动物模型。将建模成功的小鼠随机分为6组,每组12只,即空白对照组、高脂高糖模型组、二甲双胍组、黄酮低剂量组、黄酮中剂量组和黄酮高剂量组。通过灌胃二甲双胍和不同剂量的软枣猕猴桃黄酮溶液,60 d后测定小鼠空腹血糖、血清胰岛素水平、肝脏葡萄糖激酶mRNA表达量以及葡萄糖激酶活性。结果表明,与高脂高糖模型组相比,黄酮中剂量组和高剂量组均可有效降低小鼠空腹血糖和胰岛素水平;3种软枣猕猴桃黄酮剂量组均可促进肝脏葡萄糖激酶mRNA表达量,并显著提高葡萄糖激酶活性。该研究为软枣猕猴桃黄酮作为调节糖代谢功能成分开发奠定理论基础。     

银杏叶聚戊烯醇对小鼠免疫功能和诱导肿瘤细胞凋亡的研究

用不同剂量银杏叶聚戊烯醇(GP)给正常小鼠和荷瘤小鼠灌胃,用碳粒廓清法分析正常小鼠巨噬细胞吞噬功能;采用流式细胞术(FCM)检测S180荷瘤小鼠的凋亡细胞比率(APO)、S期细胞比率(SPF)和增殖指数(PI)的变化,分析T细胞亚群CD4/CD8比值的影响.结果表明,10和20 mg/kg的GP能提高正常小鼠巨噬细胞的吞噬功能, 对碳粒的清除作用高于环磷酰胺(CTX);高剂量组(40 mg/kg)GP与对照组比较,能增加肝癌(Heps)荷瘤小鼠胸腺指数和艾氏腹水癌(EC)荷瘤小鼠脾指数.5 mg/kg GP对S180荷瘤小鼠细胞的APO为6.35, 明显高于阴性对照组及其它给药组,使S180荷瘤小鼠CD4/CD8比值接近正常小鼠.     

软枣猕猴桃解酒护肝作用的研究

软枣猕猴桃含有多种功能性成分,为深入研究软枣猕猴桃的营养价值,以软枣猕猴桃冻干粉为研究对象,对健康大鼠利用食用级75%的乙醇灌胃构建急性酒精中毒动物模型,对动物的一般形态、血清乙醇浓度、肝组织抗氧化能力及醒酒指标进行测定,比较软枣猕猴桃低、中、高剂量干预组的解酒护肝作用。结果表明:软枣猕猴桃高剂量20mL·kg^-1干预组大鼠血清乙醇质量浓度为655.239±87.31mg·kg^-1,乙醇脱氢酶浓度为13.27±2.01mol·kg^-1,超氧化物歧化酶浓度78.12±3.12mol·L^-1,总胆固醇、丙二醛分别为0.591±0.0088mol·L^-1、2.879±0.0187mol·L^-1,各项指标显著优于模型组大鼠。软枣猕猴桃高剂量干预组对酒精及有害物质在大鼠体内的积累有较好的代谢作用,能够缩短急性酒精中毒大鼠的醉酒时间,具有解酒护肝的作用。     

沙棘—山楂汁对小鼠血脂的影响

将6周龄BALB/C雄性小鼠40只随机分为对照、高脂和沙棘三组,对照组喂基础饲料,饮自来水;高脂组和沙棘组小鼠喂以高脂饲料,分别饮用自来水和沙棘—山楂汁。喂养45d,采尾血测定血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL—C)含量,并断头取血测定血浆卵磷脂胆固醇酰基转移酶(LCAT)相对活性。结果表明,沙棘组小鼠与高脂组比较TC、TG显著降低(P<0.01),HDL—C明显升高(P<0.05),动脉硬化指数TC—HDL—C/HDL—C和LDL—C/HDL—C也显著降低。LCAT相对活性则有显著的提高(P<0.05)。说明沙棘—山楂汁具有降血脂和抗动脉粥样硬化作用。     

Hypoglycemic effect of protopanaxadiol-type ginsenosides and compound K on Type 2 diabetes mice induced by high-fat diet combining with streptozotocin via suppression of hepatic gluconeogenesis

Compound K (CK) is a final intestinal metabolite of protopanaxadiol-type ginsenosides (PDG) from Panax ginseng. Although anti-diabetic activity of CK have been reported with genetic mouse models (db/db mice) in recent years, the therapeutic usefulness of CK and PDG in type 2 diabetes, a more prevalent form of diabetes, remains unclear. In the present investigation, we developed a mouse of non-insulin-dependent diabetes mellitus that closely simulated the metabolic abnormalities of the human disease. For this purpose, type 2 diabetes was induced in male ICR mice by combining of streptozotocin. The male ICR mice fed with HFD for 4 weeks received 100 mg/kg of STZ injected intraperitoneally. After 4 weeks, mice with fasting (12 h) blood glucose levels (FBG) above 7.8 mmol/L were divided into 3 groups (n = 12) and treated with vehicle (diabetes model, DM), 300 mg/kg/day of PDG and 30 mg/kg/day of CK for 4 weeks while continuing on the high-fat diet. Hypoglycemic effects of CK and PDG were consistently demonstrated by FBG levels, and insulin-sensitizing effects were seen during oral glucose tolerance testing (OGTT). Moreover, the mechanism of hypoglycemic effect in type 2 diabetic mice was examined. Gluconeogenic genes, Phosphoenolpyruvate carboxykinase (PEPCK) and Glucose-6-phosphatase (G6Pase), were decreased in two treatment groups with CK showing greater effects. These findings demonstrated the hypoglycemic and insulin-sensitizing capabilities of CK on type 2 diabetes induced by HFD/STZ via down-regulation of PEPCK and G6Pase expression in liver.     

The effect of aqueous extract of gross and commercial yerba mate (Ilex paraguariensis) on intra-abdominal and epididymal fat and glucose levels in male Wistar rats

This study analyzed the plasma lipid profile, glucose levels and fat deposits in male rats treated with aqueous extract of gross yerba mate, commercial yerba mate or water. Yerba mate treatment did not change body weight gain and lipid profile. The consumption of gross yerba mate significantly increased blood glucose (6.6 mmol/L) as compared to the water (4.8 mmol/L) and commercial group (5.2 mmol/L) and decreased epididymal and intra-abdominal deposits (10.1 mg/g and 23.7 mg/g of weight) as compared to the water (15.4 mg/g and 36.9 mg/g of weight) and commercial group (12.5 mg/g and 28 mg/g of weight). The results suggest that gross yerba mate reduces fat more efficiently but produces a greater increase in blood glucose when compared to commercial yerba mate and water groups.     

Anti-diabetic effect of American ginseng may not be linked to antioxidant activity: Comparison between American ginseng and Scutellaria baicalensis using an ob/ob mice model

Antioxidants have been considered as a useful remedy in diabetes therapeutics, and thus, herbal medicines with antioxidant properties may play major role in treating diabetes. In this report, we performed a comparative study using American ginseng and Scutellaria baicalensis to test whether the anti-diabetic effect of American ginseng is associated with its antioxidant activity. We used a simple water extraction procedure to prepare American ginseng root extract (AGE) and S. baicalensis extract (SbE), and utilized these two antioxidant herbs to evaluate their anti-diabetic effect in obese diabetic ob/ob mice. HPLC analysis was used to identify major constituents in the AGE and SbE. After 12 days of daily intraperitoneal injection, AGE at 300 mg/kg showed significant effects on fasting blood glucose levels (P < 0.01) and glucose tolerance test (P < 0.01) compared to vehicle-treated mice. Animal body weights also reduced significantly after 12-day treatment (P < 0.01). However, SbE, a very strong antioxidant extract, administered at 5–50 mg/kg (based on our previous studies without adverse events) for 12 days did not show any significant effects on blood glucose and body weight changes. No effects were shown when baicalein, an effective antioxidant constituent in SbE, was administered at 1–5 mg/kg. It appears that the anti-diabetic effect of American ginseng may not be linked to its antioxidant actions. The mechanisms of American ginseng's effects on reducing high blood glucose levels and body weight remain to be investigated in future experiments.     

Fucoidan regulate blood glucose homeostasis in C57BL/KSJ m+/+db and C57BL/KSJ db/db mice

Type 2 diabetes mellitus is a multisystem disease that is characterized by hyperglycemia and is associated with the dysfunction and failure of various organs. The control of postprandial hyperglycemia is important in the prevention and intervention of type 2 diabetes. Fucoidan has several biological activities in vitro and in vivo. However, the effect of fucoidan on hyperglycemia in non-diabetic and diabetic mice has not been investigated. This study was undertaken to study the effects of different molecular weight forms (5 kilodalton (k), 5-30 k and crude) of fucoidan on oral glucose tolerance tests in non-diabetic mice and on food intake, weight gain, fasting blood glucose and blood biochemistry of db/db mice. Treatment with 200 mg/mL 5 k, 5-30 k and crude fucoidan substantially prevented hyperglycemia according to oral glucose tolerance tests in non-diabetic mice. In addition, fucoidan fractions significantly reduced blood glucose levels in diabetic mice.     

Effects of E/Z isomers of lycopene on experimental prostatic hyperplasia in mice

AimLycopene is a member of the carotenoid family and has strong anti-oxidant properties. Lycopene occurs in tomato-based food products primarily as an all-E isomer (80–97%),but its Z-isomers accounts for 79 to 88% of total lycopene in benign or malignant prostate tissues, while the specific biological functions of Z-isomers are still not clarified at present. This study was to examine the bioactive potency of Z-isomers on benign prostatic hyperplasia (BPH) in mice and to make a comparison of effective inhibition between Z-isomers and all-E isomer.MethodMice were divided into the Saline group, Vehicle control group and testosterone propionate induced BPH mice group (BPH model group, vehicle BPH model group, lycopene treated (5 mg/kg and 2.5 mg/kg), Z-isomers (57%) treated, Z-isomers (86%) treated, finasteride treated). The drugs were orally administered once a day consecutively for 30 days. The inhibitory effects on BPH of all-E lycopene and Z-isomers were evaluated by prostatic index, prostatic acid phosphatase (PAP), estradiol, testosterone and dihydrotestosterone (DHT) levels in serum and histopathology examination.ResultsCompared with the BPH model group, E/Z isomers exhibited significant differences in prostatic index, PAP, estradiol, testosterone and DHT levels in serum and similar histological aspects observed in the mice of the control group. The present research also shows that Z-isomers may be more potent inhibitors than all-E isomers in BPH treatment.     

Breaking Seed Dormancy of Laurel (Laurus nobilis L.)

Laurel (Laurus nobilis L.) seeds were collected from the west part of Turkey in the fall of 2002. Seeds with pericarp (+) or without pericarp (−) were treated with 1000 mg/l, 2000 mg/l and 3000 mg/l GA₃ concentrations, cold stratified at +4 ± 1°C for 25 and 50 days, punctured and seed coat removed to overcome and assess the mechanism of laurel seed dormancy. A period of 50 days cold stratification and removing seed coat significantly increased germination rate to 55% ± 1.91 (Mean ± SE) and 85% ± 3.00, respectively. None of the seeds with pericarp germinated regardless of treatment they underwent. Results suggested that seed dormancy was mainly due to pericarp and perhaps inhibitors linked to seed coat.     

Effects of eugenol on hepatic glucose production and AMPK signaling pathway in hepatocytes and C57BL/6J mice

Eugenol is a phenylpropanoid with many pharmacological activities, but its anti-hyperglycemic activity is not yet fully explored. For in vitro study, HepG2 cells and primary rat hepatocytes were used, and glucose production was induced by adding 100 nM of glucagon in the presence of gluconeogenic substrates. In animal study, hyperglycemia was induced by high fat diet (HFD) in male C57BL/6J mice, and eugenol was orally administered at 20 or 40 mg per kg (E20, E40) for 15 weeks. Eugenol significantly inhibited glucagon-induced glucose production and phosphorylated AMPK in the HepG2 and primary rat hepatocytes, and these effects were reversed in the presence of compound C (an AMPK inhibitor) or STO-609 (a CAMKK inhibitor). In addition, the protein and gene expression levels of CREB, CRTC2 · CREB complex, PGC-1α, PEPCK and G6Pase were all significantly suppressed. Moreover, inhibition of AMPK by over-expression of dominant negative AMPK prevented eugenol from suppressions of gluconeogenic gene expression and hepatic glucose production. In animal study, plasma glucose and insulin levels of the E40 group were decreased by 31% and 63%, respectively, when compared to those of HFD control. In pyruvate tolerance tests, pyruvate-induced glucose excursions were decreased, indicating that the anti-hyperglycemic activity of eugenol is primarily due to the suppression of hepatic gluconeogenesis. In summary, eugenol effectively ameliorates hyperglycemia through inhibition of hepatic gluconeogenesis via modulating CAMKK-AMPK-CREB signaling pathway. Eugenol or eugenol-containing medicinal plants could represent a promising therapeutic agent to prevent type 2 diabetes.     

Some biological interactions between the parasitoid <Emphasis Type="Italic">Anagyrus pseudococci</Emphasis> (Girault) (Hymenoptera: Encyrtidae) and its host <Emphasis Type="Italic">Planococcus ficus</Emphasis> (Signoret) (Hemiptera: Coccoidea: Pseudococcidae)

The development, longevity, fecundity and life-table parameters of the endoparasitoid Anagyrus pseudococci (Girault) (Hymenoptera: Encyrtidae), 15 d.o. (3rd-instar nymphs) and 21 d.o. (young adult females) of the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) at 28 ± 1°C, 65 ± 10%RH and 16:8h L:D under laboratory conditions. The developmental time of female parasitoids within the host was 17.7 ± 0.39 days in 15 d.o. and 16.65 ± 0.25 days in 21 d.o. hosts; for males, development time was 16.85 ± 0.29 and 15.25 ± 0.09 days, respectively. The average number of offspring per female was 22.35 ± 1.68 in 15 d.o. and 34.8 ± 2.56 in 21 d.o. vine mealybugs. The longevity of female parasitoids was 14.8 ± 0.98 days in 15 d.o. and 15.65 ± 0.92 days in 21 d.o. mealybugs, respectively; for males, longevity was determined as 7.3 ± 0.43 and 6.7 ± 0.54 days, respectively. The mean time of pupation was 7.85 ± 0.003 days in 15 d.o. mealybugs and 8.65 ± 0.003 days in 21 d.o. mealybugs. The aggregate encapsulation rate in the parasitized 15 d.o. mealybugs was 49.73 and 60.36% in 21 d.o. mealybugs. Furthermore, effective encapsulation was 24.82% in 15 d.o. mealybugs and 37.50% in 21 d.o. mealybugs. Population growth rate (r _m) for A. pseudococci was 0.0999 female/female/days in 15 d.o. mealybugs and 0.1269 female/female/days in 21 d.o. mealybugs. The mean population generation time was 23.49 days for parasitoids reared in 15-days-old and 22.39 days when reared in 21 d.o. mealybugs.     

Hypoglicemic effect of Leandra lacunosa in normal and alloxan-induced diabetic rats

Leandra lacunosa, popularly known as "erva-do-jabuti", is used in Brazilian folkloric medicine for the treatment of diabetes mellitus. Based on this traditional indication, the aim of this work was to evaluate the hypoglycemic activity of the hydroalcoholic extract of L. lacunosa aerial parts (LLH) in normal and alloxan-induced diabetic rats. Chromatographic fractionation of LLH was also carried out by several techniques, affording isolation of the following major compounds: ursolic acid (1), kaempferol (2), luteolin (3), and quercetin (4). The oral administration of LLH (500 mg/kg) in normal rats caused a significant reduction of 24.7% (P<0.05) in the blood glucose levels after 2 h of treatment, while the administration of chlorpropamide (20 mg/kg, p.o.) led to a reduction of 40.2% (P<0.01). After oral administration of glucose (10 g/kg, p.o.), LLH (500 mg/kg, p.o.) significantly inhibited the increase in blood glucose levels compared with the negative control group. The oral treatment with LLH (500 mg/kg) in alloxan-induced diabetic rats significantly reduced the blood glucose levels in 47.8% after 4 h of treatment, while chlorpropamide resulted in a significant reduction of 71.7% in the 4th hour. Our results showed that LLH, displays hypoglycemic activity, which may be related to the effect of the major compounds identified in the crude extract. This study seems to provide biological evidence for the folkloric use of L. lacunosa in the treatment of diabetes mellitus.