Inhibitory effects of compounds from Anemarrhenae Rhizoma on α-glucosidase and aldose reductase and its contents by drying conditions

An aqueous extract of Anemarrhena asphodeloides Bunge (Anemarrhenae Rhizoma) showed inhibitory effects on α-glucosidase and aldose reductase (AR). We obtained two active compounds, mangiferin (α-glucosidase: IC₅₀ = 96.1 μg/ml, AR:IC₅₀ = 0.13 μg/ml) and mangiferin 7-O-β-D-glucopyranoside (α-glucosidase: IC₅₀ = 158 μg/ml, AR:IC₅₀ = 65.7 μg/ml ), from Anemarrhenae Rhizoma. In addition, the amount of mangiferin in Anemarrhenae Rhizoma changed with the method of preparation (drying conditions), namely, low-temperature, long-term drying conditions and harvesting in August were most effective.     

Inhibitory effects of S-nitrosocaptopril on vasomotor tone

目的：观察巯亚硝酰卡托普利（ＣａｐＮＯ）和卡托普利（Ｃａｐ）对血管紧张性的影响．方法：记录家兔胸主动脉环张力和大鼠肾动脉灌流压（ＰＰｒ）．结果：ＣａｐＮＯ对苯福林预收缩的内皮完整与去内皮主动脉环，均呈浓度依赖性（３０ｎｍｏｌ·Ｌ－１－１０μｍｏｌ·Ｌ－１，Ｐ＜００１）的舒张作用，而相同浓度的Ｃａｐ作用不显著；ＣａｐＮＯ降低ＰＰｒ的作用亦呈浓度依赖性（１０ｎｍｏｌ·Ｌ－１－１０００ｎｍｏｌ·Ｌ－１，Ｐ＜００１），而Ｃａｐ只在１０００ｎｍｏｌ·Ｌ－１呈显著性变化；Ｎ单甲基左旋精氨酸和左旋精氨酸预处理均不影响ＣａｐＮＯ诱发的降ＰＰｒ作用．结论：ＣａｐＮＯ具有直接降低血管紧张性作用．     

Inhibitory effects of copper-aspirin complex on platelet aggregation

目的：研究阿司匹林铜（ＣｕＡｓｐ）对血小板聚集性的影响及其机制．方法：用Ｂｏｒｎ氏法测定ＣｕＡｓｐ对兔血小板聚集性的影响．用荧光光度法和放射免疫法观察ＣｕＡｓｐ对兔血小板５羟色胺的释放和ＴＸＢ２的产生及血浆中ＴＸＢ２和６ｋｅｔｏＰＧＦ１α水平的影响．结果：ＣｕＡｓｐ体外呈浓度依赖性抑制花生四烯酸（ＡＡ）诱导的血小板聚集和５羟色胺的释放（ＩＣ５０分别为１７和１９μｍｏｌ·Ｌ－１，９５％可信限为９－３３和１０－３０μｍｏｌ·Ｌ－１），且抑制ＴＸＢ２的产生（Ｐ＜００５）．ＣｕＡｓｐ１０ｍｇ·ｋｇ－１灌胃选择性抑制ＡＡ诱导聚集．降低血浆ＴＸＢ２，同时升高６ｋｅｔｏＰＧＦ１α的水平（Ｐ＜００５）．结论：ＣｕＡｓｐ体内外均有比Ａｓｐ更强的抗血小板聚集作用．     

Comparative study on α-glucosidase inhibitory effects of total iridoid glycosides in the crude products and the wine-processed products from Cornus officinalis

To compare the difference of α-glucosidase inhibitory effect of total iridoid glycosides from crude products and processed products (Paozhi in Chinese) of Cornus officinalis Sieb. et Zucc. by α-glucosidase and glucose tolerance test in mice. Alcohol 40% was employed to extract the total iridoid glycosides from the crude products and the processed products then the total iridoid glycosides were enriched through macroporous resins to obtain SZY-1 and SZY-2 from the crude products and the processed products, respectively. The inhibitiory activity of these extracts was investigated on α-glucosidase inhibition in vitro and glucose tolerance test in vivo. The results demonstrated that both SZY-1 and SZY-2 were successfully enriched by macroporous resins. The contents of the total iridoid glycoside in SZY-1 and SZY-2 were 75.3% and 42.8%, respectively, and exerted inhibitory effects at various concentrations on α-glucosidase. The maximal inhibition ratio (86%) of SZY-1 was markedly higher than that of SZY-2. Meanwhile, SZY-1 was more potent than SZY-2 in decreasing blood sugar in diabetic mice induced by streptozotocin. Their effects were dependent on the dosage. In conclusion, the iridoid total glycoside from crude products and processed products of C. officinalis had α-glucosidase inhibitory effects in vitro and in vivo, and the effects of the crude products ware superior to those of processed products. It was also suggested that the hypoglycemic effects of C. officinalis may be attributable to its total iridoid glycoside.     

Diterpenoids from the roots of Euphorbia fischeriana and their inhibitory effects on α-glucosidase

Abstract

Chemical investigation has been performed on the roots of Euphorbia fischeriana, a traditional Chinese medicine. Three diterpenoids were obtained using various chromatographic techniques, and their structures were determined by spectroscopic data including HRESIMS, 1D NMR, 2D NMR, ECD, and calculated ECD, which gave two new diterpenoids, daphnane type (1) and ent-pimarene type (3). Additionally, the isolated compounds (1–3) displayed moderate inhibitory effects against α-glucosidase in an in vitro bioassay.     

Inhibitory activity of α-amylase and α-glucosidase by plant extracts from the Brazilian cerrado

Diabetes mellitus is the most common disease in the world. One therapeutic approach for treating diabetes is inhibition of α-amylase and α-glucosidase activities to reduce postprandial blood glucose levels. In vitro tests showed that several plant extracts from Brazilian cerrado species can inhibit the activity of α-amylase and α-glucosidase. The extracts of Eugenia dysenterica, Stryphnodendron adstringens, Pouteria caimito, Pouteria ramiflora, and Pouteria torta showed strong α-amylase and α-glucosidase inhibitory activity. Eugenia dysenterica, P. caimito, P. ramiflora, and P. torta aqueous extracts exerted the highest activity against α-amylase (IC??) values of 14.93, 13.6, 7.08, and 5.67 μg/mL, respectively) and α-glucosidase (IC?? values of 0.46, 2.58, 0.35, and 0.22 μg/mL, respectively). Stryphnodendron adstringens ethanol extract also exhibited inhibitory activity against both enzymes (IC??) 1.86 μg/mL against α-amylase and 0.61 μg/mL against α-glucosidase). The results suggest that the activity of these cerrado plants on α-amylase and α-glucosidase represents a potential tool for development of new strategies for treatment of diabetes.     

Inhibitory effects of nimodipine on platelet aggregation and thrombosis

目的：研究尼莫地平（Ｎｉｍ）对大鼠体内血小板聚集和动脉血栓形成的影响．方法：比浊法测定血小板的聚集率和抑制率；电刺激法测定Ｎｉｍ对体内动脉血栓形成的影响，放免法测定Ｎｉｍ对血浆６酮前列腺素Ｆ１α和血栓素Ｂ２（６ｋｅｔｏＰＧＦ１α／ＴＸＢ２）含量的影响．结果：Ｎｉｍ４５，９，１８和３６ｍｇ·ｋｇ－１·ｄ－１ｉｇ４ｄ可显著抑制血小板的聚集．ＩＣ５０（９５％可信限）为２６（９－４４）ｍｇ·ｋｇ－１．Ｎｉｍ４５，９，１８ｍｇ·ｋｇ－１·ｄ－１ｉｇ４ｄ可显著延长电刺激诱导的颈动脉血栓形成时间．Ｎｉｍ９和１８ｍｇ·ｋｇ－１可明显改善血浆中６ｋｅｔｏＰＧＦ１α／ＴＸＢ２的比值．结论：Ｎｉｍ抗血栓作用部分与改善６ｋｅｔｏＰＧＦ１α／ＴＸＢ２比值有关．     

Inhibitory potential of traditional herbs on α-amylase activity

Context: There has been enormous interest in the development of alternative medicines for the control of diabetes. Use of carbohydrate-hydrolyzing enzyme inhibitors proved to be an important strategy for the management of postprandial hyperglycemia by delaying the process of carbohydrate hydrolysis and absorption.

Objective: Three common traditional herbs, namely, stem bark of Terminalia arjuna (Combretaceae), seeds of Eugenia cumini (Myrtaceae), and leaves of Aegle marmelos (Rutaceae), were tested for their α-amylase inhibitory activities to establish antidiabetic potential.

Materials and methods: The plant extracts (aqueous, 50%, and 100% methanol) obtained were subjected to an in vitro amylase inhibitory assay using starch as a substrate and pancreatic amylase as the enzyme. Statistical differences and linear regression analysis were performed using GraphPad prism 5 software.

Results: The 50% methanol extracts of T. arjuna, E. cumini, and A. marmelos at a concentrations 50–500 μg/mL showed maximum percentage inhibition on amylase activity with IC₅₀ values of 302?±?0.55, 632?±?0.21, and 503?±?0.28 μg/mL, respectively. However, the 100% methanol extracts of all the three plants showed the least inhibitory activity.

Discussion and conclusion: The results show that T. arjuna > E. cumini > A. marmelos have excellent inhibitory activity and, therefore, might be effective in lowering postprandial hyperglycemia.     

Inhibitory effects of vinpocetine on sodium current in rat cardiomyocytes

目的：研究长春西汀对心肌细胞钠电流的作用．方法：用全细胞膜片箝技术记录大鼠心肌细胞钠电流．结果：长春西汀可逆性抑制心肌细胞钠电流的作用为剂量依赖性和电压依赖性，但未发现频率或使用依赖性．长春西汀１０－８０μｍｏｌ·Ｌ－１，对钠电流的抑制作用为１３％±２％至７５％±６％．半数抑制浓度ＩＣ５０值（９５％可信限）为３６４（２８１－４７１）μｍｏｌ·Ｌ－１．在膜电位以１０ｍＶ的间隔从－９０ｍＶ阶梯状去极化至＋４０ｍＶ时，抑制作用呈逐渐增加的趋势，约在０ｍＶ左右达到最大抑制．长春西汀对钠通道的稳态激活和失活过程的影响，可使钠窗电流（缓慢失活的钠电流）减少．结论：长春西汀抑制大鼠心肌细胞的钠电流     

Inhibitory effects of captopril on c-myc expression during left ventricular hypertrophy

目的：观察卡托普利（Ｃａｐ）对原癌基因ｃｍｙｃ在自发性高血压大鼠（ＳＨＲ）左心室心肌不同细胞类型的表达的影响，探讨Ｃａｐ抑制左心室肥大的分子机制．方法：ＳＨＲ宫内期口服给药（１００ｍｇ·ｋｇ－１·ｄ－１），雄性ＳＨＲ１６周龄时测定收缩压、左室重与体重比．左心室ｃｍｙｃｍＲＮＡ，ＡｎｇⅡ及ｃｍｙｃ癌蛋白表达量分别用ＲＮＡ印迹、免疫组化及蛋白质印迹测定．结果：Ｃａｐ明显降低ＳＨＲ大鼠的收缩压，抑制左心室肥大及ｃｍｙｃ表达，心肌局部ＡｎｇⅡ主要产生于心肌细胞，ｃｍｙｃ则主要源于成纤维细胞．结论：Ｃａｐ通过抑制心肌细胞的ＡｎｇⅡ和成纤维细胞的ｃｍｙｃ表达而逆转左心室肥大     

Inhibitory effects of cyproheptadine on pituitary-thyroid axis and pancreatic β cells in rats

目的：研究赛庚啶（Ｃｙｐ）对大鼠垂体甲状腺轴和胰岛β细胞内分泌功能的影响．方法：用放射免疫测定法及生化分析法观察赛庚啶对大鼠垂体甲状腺轴和胰岛β细胞内分泌功能的影响．结果：Ｃｙｐ２３ｍｇ·ｋｇ－１，ｉｇ１０ｄ，使大鼠血清ＴＳＨ、胰岛素含量均降低，而Ｔ３、Ｔ４及血糖水平无明显改变．Ｃｙｐ４６ｍｇ·ｋｇ－１引起血清ＴＳＨ、Ｔ３、Ｔ４和胰岛素含量显著降低，血糖水平明显升高；垂体ＴＳＨ细胞和胰岛β细胞的超微结构亦发生不同程度的退行性变化．结论：Ｃｙｐ对垂体甲状腺轴和胰岛β细胞的内分泌功能有抑制作用     

Inhibitory effects of N4 on membrane phospholipase A2 from porcine pancreas

AIM: To explore the potential mechanism of anti-inflam matory actions by N_(14). METHODS: Microplate assay and radioimmunoassay were applied respectively to investigate effects of N_(14) on porcine pancreatic phospholipese A_2(PLA_2) and cyclooxygenase of rabbit platelet. RE     

Inhibitory effects of asiaticoside on nitric oxide production in neonatal rat microglia cultures

Asiaticoside, one or the components extracted from Centella asiatica (L) Urban which has anti-viral and anti-inflammatory actions, was studied on nitric oxide (NO) production from primary cultured rat microglia in vitro. NO concentration was represented by nitrite and determined by Oriess reaction. Asiaticoside did not show any inhibiton on NO production in resting microglia,but significantly decreased its levels in lipoplysaccharides-stimulated rat microglia at the concentration 10     

Evaluation of polyhydroxybenzophenones as α-glucosidase inhibitors

This experiment was designed to synthesize 18 kinds of polyhydroxybenzophenones by using Friedel‐Crafts reaction, and to measure the inhibitory activity on α‐glucosidase with p‐nitrophenyl‐β‐D‐galactopyranoside (PNPG) as a substrate. Here, acarbose (IC₅₀ = 1674.75 µmol L^?1) was used as the reference inhibitor. The results demonstrated that most of the target compounds had remarkable inhibitory activities on α‐glucosidase. Among all these compounds, 2,4,4′,6‐butahydroxydiphenylketone ( 11 ) was found to be the most potent α‐glucosidase inhibitor with an IC₅₀ value of 10.62 µmol L^?1. In addition, we found these compounds were competitive inhibitors through the kinetic analysis. The results suggested that such compounds might be utilized for the development of new candidates for diabetes treatment.     

Inhibitory effects of tanshinone Ⅱ-A on invasion and metastasis of human colon carcinoma cells

Aim:

To investigate the effects and possible mechanisms of tanshinone II-A, an alcohol extract of the root of Salvia miltiorrhiza Bunge, on tumor invasion and metastasis of human colon carcinoma (CRC) cells.

Methods:

The effects of tanshinone II-A on invasion and metastasis of CRC cell lines HT29 and SW480 were evaluated by in vitro and in vivo assays. Western blotting was used to investigate possible molecular mechanisms of tanshinone II-A anti-cancer actions.

Results:

Tanshinone II-A inhibited migration and invasion of CRC cells in a dose-dependent manner. The inhibitory effect also depended on time, with the most significant effects observed at 72 h. Tanshinone II-A also significantly inhibited in vivo metastasis of colon carcinoma SW480 cells. It inhibited in vitro and in vivo invasion and metastasis of CRC cells by reducing levels of urokinase plasminogen activator (uPA) and matrix metalloproteinases (MMP)-2 and MMP-9, and by increasing levels of tissue inhibitor of matrix metalloproteinase protein (TIMP)-1 and TIMP-2. Tanshinone II-A was also shown to suppress the nuclear factor-kappaB (NF-κB) signal.

Conclusion:

Tanshinone II-A inhibited in vitro and in vivo invasion and metastasis of CRC cells. The effect resulted from changes in the levels of uPA, MMP-2, MMP-9, TIMP-1 and TIMP-2, and apparent inhibition of the NF-κB signal transduction pathway.     

Do arterial effects of antihypertensive drugs depend on subject's serum cholesterol?

Effects of antihypertensive treatment on large arteries may be influenced by the type of drug and concomitant risk factors such as blood cholesterol. To explore these possibilities we investigated the common carotid artery of 20 subjects with low cholesterol and 19 subjects with high cholesterol, all with essential hypertension, randomly allocated to 3 months of treatment with nitrendipine (20 mg/d) or trandolapril (2 mg/d). Carotid parameters were determined by recording instantaneous pressure (applanation tonometry) and diameter (echotracking device) and by modeling the pressure-diameter loop to obtain the Peterson modulus, stiffness index, measured and isobaric compliances, and wall viscosity. Effects of drugs on carotid parameters did not differ, except on systolic and diastolic diameters (p < 0.01), which increased insignificantly under nitrendipine but decreased (p < 0.01) under trandolapril. Blood cholesterol status did not influence carotid effects of trandolapril, whereas patients with low and high cholesterol treated with nitrendipine exhibited significant differences in drug effects on (a) systolic and pulse pressures (p < 0.05), which decreased in patients with low cholesterol (p < 0.01, p < 0.05) but not in those with high cholesterol; (b) diastolic diameter (p = 0.05), which increased insignificantly in patients with low cholesterol but was unchanged in those with high cholesterol; and (c) wall viscosity (p < 0.01), which decreased in patients with low cholesterol (p < 0.05) but increased insignificantly in those with high cholesterol. Also, wall viscosity change under nitrendipine was positively related to the baseline blood cholesterol ( r = 0.64, p < 0.01). Thus, nitrendipine and trandolapril show noteworthy differences in their effects on the carotid artery, in particular with respect to the status of blood cholesterol, but these differences should be confirmed by larger studies.     

Inhibitors of α-glucosidase and α-amylase from Cyperus rotundus

Context: A methanol extract of Cyperus rotundus L. (Cyperaceae) rhizomes showed inhibitory activity against α-glucosidase and α-amylase, two enzymes involve in carbohydrate digestion.

Objective: Identification of compounds from C. rotundus rhizomes responsible for the inhibition of α-glucosidase and α-amylase.

Materials and methods: Compounds were identified by a phytochemical investigation using combined chromatographic and spectroscopic methods. α-glucosidase and α-amylase inhibitory activities were evaluated by in vitro enzyme inhibition assays.

Results: A new (2RS,3SR)-3,4′,5,6,7,8-hexahydroxyflavane (1), together with three known stilbene dimers cassigarol E (2), scirpusin A (3) and B (4) were isolated. Compound 2 inhibited both α-glucosidase and α-amylase activities while the flavane 1 only showed effect on α-amylase, and compounds 3 and 4 were active on α-glucosidase. All four compounds showed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity.

Discussion: The inhibitory activities against α-amylase and α-glucosidase of the C. rotundus rhizomes were reported for the first time. Stilbene dimers are considered as potent inhibitors of α-glucosidase and promising antihyperglycemic agents.

Conclusion: The isolated compounds may contribute to the antidiabetic property of C. rotundus.     

Inhibitory effects of ginkgolides on nitric oxide production in neonatal rat microglia in vitro

目的：观察银杏内酯Ａ和Ｂ，ＰＡＦ拮抗剂阿帕泛（Ａｐａ）和ＮＯＳ抑制剂ＬＮＡ对新生大鼠小胶质细胞（Ｍｉ）产生ＮＯ的影响．方法：以Ｇｒｉｅｓ反应测定亚硝酸盐含量表示ＮＯ量．结果：在静息Ｍｉ，ＧＡ，ＧＢ和Ａｐａ在１－１００００ｎｍｏｌ·Ｌ－１范围对Ｍｉ产生ＮＯ没有影响，但ＬＮＡ可浓度依赖性地抑制ＮＯ产生，其ＩＣ５０（９５％可信限）值为３．４（０．８－１４９）μｍｏｌ·Ｌ－１．而在激活的Ｍｉ，ＧＡ，ＧＢ和ＬＮＡ可浓度依赖性地抑制ＮＯ产生，其ＩＣ５０（９５％可信限）值分别为５．７（１．８－１８１），１．１（０．３－４４）和０．５（０．１－２．８）μｍｏｌ·Ｌ－１，但Ａｐａ不能抑制ＮＯ产生．结论：ＧＡ和ＧＢ抑制ＬＰＳ诱导Ｍｉ产生ＮＯ．