Antihypertensive effect of an aqueous extract of the calyx of Hibiscus sabdariffa

The present study was designed to investigate the efficacy of an aqueous calyx extract of Hibiscus sabdariffa (HS) in two forms of experimental hypertension: salt-induced and L-NAME (N(omega)-L-arginine methyl ester)-induced and in normotensive controls. The blood pressure and heart rate fell dose-dependently in both the hypertensive and normotensive rats after intravenous injection of 1-125 mg/kg of HS, suggesting that HS possesses anti-hypertensive, hypotensive and negative chronotropic effects. The fall in mean arterial pressure was significantly pronounced in the hypertensive rats (salt-induced: 94.4+/-8.6 mm Hg; L-NAME-induced: 136.5+/-10.3 mm Hg) than in the normotensive controls (50.2+/-5.1 mm Hg; P<0.05).     

桦褐孔菌提取物降血脂研究

采用高脂高胆固醇诱导SD大鼠高脂血症实验模型,分析桦褐孔菌醇提物（IOE）对大鼠体重、脏器及饲喂IOE后大鼠血脂水平和动脉硬化指数。结果表明：IOE可以显著降低高脂血症大鼠血清中甘油三酯、总胆固醇的含量;IOE可以显著提高高脂血症大鼠血清中的高密度脂蛋白胆固醇的水平,降低低密度脂蛋白胆固醇的水平;IOE可以提高高脂血症大鼠的ApoA水平,降低ApoB水平;饲喂IOE后,可明显改善大鼠血脂代谢,对阻止动脉硬化的形成和恶化具有重要作用。     

Field efficacy of a biopesticide prepared from <Emphasis Type="Italic">Clerodendrum viscosum</Emphasis> Vent. (Verbenaceae) against two major tea pests in the sub Himalayan tea plantation of North Bengal,India

The toxicity of four concentrations (1, 5, 10 and 20% w/v) of an aqueous extract from the weed, Clerodendrum viscosum Ventenat (Verbenaceae) was investigated under field conditions of the North Bengal University, Darjeeling, West Bengal, India for managing two major pests of tea, Camellia sinensis (L), namely the tea mosquito bug, Helopeltis theivora Waterhouse, (Heteroptera: Miridae) and the tea red spider mite, Oligonychus coffeae Nietner, (Acarina: Tetranychidae). Four field trials, two for red spider mite and two for tea mosquito bug, were conducted during April–May 2008 and October–November 2009 following a Randomized Block design. The aqueous extract of C. viscosum effectively and significantly reduced the mite population as well as infestation of tea mosquito bug by 68–95% and 73–86%, respectively, and their bioefficacy is comparable to synthetic and neem pesticides. No phytotoxic effect (score 0–5% and grade 1) was observed in the tea bushes sprayed with different doses of aqueous extract of C. viscosum in the field. Made tea samples were taint free. Organoleptic test revealed leaf-infusions and liquor strength as good, scoring 6.5–7.0 on a 10 point scale. Availability and distribution of this weed (C. viscosum) in and around tea-growing areas of sub Himalayan region, along with its processing for the feasibility of including C. visosum extracts in the current IPM programme is discussed.     

Antiobesity and cardiovascular toxic effects of Citrus aurantium extracts in the rat: a preliminary report

The effects of repeated oral administration of 2.5–20 mg/kg of two Citrus aurantium fruit extracts standardized to different concentrations of synephrine (4 and 6%, respectively) on food intake, body weight gain, arterial blood pressure, electrocardiogram (ECG) and mortality have been investigated in the rat. C. aurantium administration significantly reduced food intake and body weight gain. However, mortality (not observed in controls) was present in all C. aurantium treated groups. Arterial blood pressure was not modified, but ECG alterations (ventricular arhythmias with enlargement of QRS complex) were evident in animals treated with both extracts. Our data indicate that, in the rat, antiobesity effects of C. aurantium are accompanied by toxic effects probably due to cardiovascular toxicity.     

竹叶提取物的化学成分及其生理功能研究进展

综述了竹叶提取物中的黄酮类化合物、多糖、特种氨基酸、挥发性成分、叶绿素、矿质元素、茶多酚等主要化学成分的种类和含量,及其抗氧化、清除自由基、防腐抑菌、抗肿瘤、调节血脂、抗衰老、抗疲劳、亚硝酸盐的清除及对N-亚硝胺合成的阻断等生理功能的研究现状;并对竹叶提取物的有效成分及其应用研究前景进行展望,提出今后竹叶提取物研究的主要方向。     

Effects of Yerba Mate tea (Ilex paraguariensis) on vascular endothelial function and liver lipoprotein receptor gene expression in hyperlipidemic rats

Yerba Mate tea (Mate), an infusion made from the leaves of the tree Ilex paraguariensis, is a widely consumed beverage in South America. This study was performed to investigate the effect of Mate tea on vascular endothelial dysfunction and liver lipoprotein receptor gene expression in hyperlipidemic rats, with the aim of gaining insight into its known lipid-lowering protective mechanisms. Sixty male Sprague–Dawley rats were randomly divided into five groups: a normal control group (NC), a high-fat diet group (HC), and three Mate tea-treated groups. In the NC group, rats were fed with standard diet while in the other groups the rats were fed a high-fat diet for 8 weeks. In the Mate tea-treated groups, the rats were fed a high-fat diet supplemented with low, moderate or high concentrations of aqueous Mate tea extract for the final 4 weeks. Compared to the HC group, aqueous Mate tea extract significantly reduced endothelin (ET) and thromboxane B₂ (TXB₂) levels and increased nitric oxide (NO) and 6-keto prostaglandin F_1α (6-keto-PGF_1α) levels in the blood, reduced the pathological damage of vascular endothelial cells, decreased intercellular adhesion molecule-1 (ICAM-1) protein expression in the thoracic aorta, and upregulated mRNA expression of hepatic low density lipoprotein receptor (LDLR) and scavenger receptor B1 (SR-B1). These findings indicate that Mate tea administration might have a regulatory effect on blood fat and endothelial function in hyperlipidemia rats. The mechanism may involve protecting vascular endothelial cell function and upregulating the expression of LDLR and SR-B1 genes, thereby inhibiting the occurrence of atherosclerosis.     

Antidiabetic activity of Caesalpinia bonducella seed extracts in rats

The seed extracts of Caesalpinia bonducella were subjected to screening of antidiabetic activity in alloxan induced hyperglycemia. The oral administration of the extracts (300 mg/kg) produced significant antihyperglycemic action as well as it lowered the BUN levels significantly. In the same study the action of the extracts on diabetes induced hyperlipidemia was analyzed where the extracts significantly lowered the elevated cholesterol as well as LDL level. The antihyperglycemic action of the extracts may be due to the blocking of glucose absorption. The drug has the potential to act as antidiabetic as well as antihyperlipidemic.     

Ilex paraguariensis extracts inhibit AGE formation more efficiently than green tea

Glycation, the nonenzymatic adduct formation between sugar dicarbonyls and proteins, is one key molecular basis of diabetic complications due to hyperglycemia. Given the link between glycation and oxidation, we hypothesized that herbal extracts with a high concentration of antioxidant phenolics might possess significant in vitro antiglycation activities as well. The aim of the present study was to address the hypothesis that polyphenol-rich Ilex paraguariensis (IP) extracts are capable of inhibiting advanced glycation end-products (AGEs) formation and to compare the potency of these extracts with green tea and with the standard antiglycation agent aminoguanidine. When we studied the effects of IP extract on AGE fluorescence generated on bovine serum albumin (BSA) by glycation with methylglyoxal, a dose-dependent effect that reaches 40% at 20 mul/ml of extract was demonstrated. Green tea did not display any significant effect. IP polyphenols are about 2- to 2.5-fold higher in our preparations compared with green tea. The effect of IP, therefore, may be due not only to the higher concentrations but to the different composition in phenolics of the two botanical preparations as well. To better discriminate between an antioxidant or a carbonyl quenching mechanism of action, we explored tryptophan fluorescence and cross-linking by sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE) electrophoresis. The conformational changes induced by glycation and substitution of positive charges in arginine and/or lysine produce a decrease in tryptophan fluorescence. We show that incubation of BSA with methylglyoxal produces dramatic changes in tryptophan fluorescence that are prevented by aminoguanidine. This also prevents the downstream effect of AGE formation. Neither green tea nor IP extracts displayed any significant effect which rules out any significant participation as inhibitors in the first phase of the glycation cascade. The results from the SDS-PAGE serve to confirm the above-mentioned data. The effect is therefore due mainly to an inhibition of the second phase of the glycation reactions, namely the free-radical mediated conversion of the Amadori products to AGE. Taken together our results demonstrate a significant, dose-dependent effect of water extracts of I. paraguensis on AGE adducts formation on a protein model in vitro, whereas green tea displays no significant effect. The inhibition of AGE formation was comparable to that obtained by using millimolar concentrations of the standard antiglycation agent aminoguanidine.     

杨树皮不饱和脂肪酸乙酯化学组成及其药效

杨树(PopulussimoniiCarr.)皮提取物经皂化、萃取、分离和精制,能够得到30%～36%的不饱和脂肪酸乙酯产品。该产品经气相色谱分析,共分离出22个色谱峰,鉴定出21个化合物,其中主要的不饱和脂肪酸乙酯成分为亚油酸乙酯,含量高达94.04%。已鉴定的组分占产品总量的99.19%,其中不饱和脂肪酸酯占95.94%,饱和脂肪酸酯占3.14%。药效试验证明,杨树皮不饱和脂肪酸乙酯产品能显著降低试验性高脂血症大鼠的血清总胆固醇(TC)、甘油三脂(TG)和低密度脂蛋白的胆固醇(LDL-C)水平(P<0.001),而对血清中高密度脂蛋白的胆固醇(HDL-C)含量有升高作用。     

Insecticidal activities and active components of the alcohol extract from green peel of Juglans mandshurica

The extract of green peel of Juglans mandshurica Maxim was extracted by common method for studying its insecticidal activities and analyzing the active components. Results showed that the alcohol extract and the chloroform part of extract （separated with chloroform from alcohol extract） form green peel of J. mandshurica have insecticidal activities in contact toxicity and stomach toxicity against larvae of Lymantria dispar L.. After application of the extracts for five days, the corrected mortality of larvae of Lymantria dispar for both extracts was more than 50% in contact toxicity and stomach toxicity at the concentration of ≥ 5 g·L^-1. The insecticidal activity for both alcohol extract and chloroform part of extract is more effect in contact toxicity than in stomach toxicity, but no significant difference in the insecticidal activities was found between alcohol extract and chloroform part of extract. The active components in the chloroform part of extract from green peel of.J. mandshurica were analyzed by GC-MS. The analyzed results showed that the active components in the chloroform part of extract are： （1） joglone （5-hydroxy-1,4- naphthaoquinone）, the relative content 27.11%, （2） 1,5-Naphthalenediol, the relative content 9.52%, （3） 7-Methoxy-1-tetralone, the relative content 6.81%, （4） Benzofuran, 2,3-dihydro-, the relative content 6.76%, （5） 4-Hydroxy-2-methoxycinnamaldehyde, the relative content 3.99%, （6） 2-Methoxy-4-vinylphenol, the relative content 3.05%.     

瑞香狼毒超临界萃取物的化学成分及其杀螨活性

我国农业害螨的抗药性越发严重,在防治过程中害螨的天敌也受到杀伤,造成害螨的再猖獗,严重影响农作物及经济林的产量和品质(Kalaisekar et al.,2003;Shi et al.,2004)。瑞香狼毒(Stellera chamaejasme)是对我国草地危害较重的有毒植物之     

Hypoglycaemic activity of Alpinia galanga rhizome and its extracts in rabbits

This investigation was carried out to study effects of Alpinia galanga rhizome on blood glucose levels. In normal rabbits, powdered rhizome and its methanol and aqueous extracts significantly lowered the blood glucose. Gliclazide also produced a significant decrease in blood glucose in the rabbits. In alloxan-diabetic rabbits, A. galanga and its methanol and aqueous extracts did not produce significant reduction in blood glucose. The hypoglycaemic effect of A. galanga in normal rabbits was comparable to gliclazide. The rhizome was found to contain high levels of certain minerals. Acute toxicity and behavioral studies revealed no visible signs of toxicity and any abnormal behavior in rabbits even at high doses. It is concluded that A. galanga produces fall in blood glucose levels in normal rabbits and the principles, both organic and inorganic, are extractable in methanol and water.     

狼毒根提取物的生物活性测定

狼毒是我国北方普遍生长的一种有毒植物,其根是一种传统中药材。20世纪90年代中期以来,作为一种植源性农药资源,狼毒的开发研究受到重视。本研究表明不同狼毒根提取物都能表现出一定的生物活性,利用狼毒根水浸液与乙醇提取物对舞毒蛾幼虫的拒食作用最高达99％,7d的校正死亡率最高达100％,室内毒力测定中防后5d的校正死亡率最高达100％;不同有机溶剂对狼毒根乙醇提取物萃取分离得到的有效成分对油松毛虫的拒食作用最高达92．39％,7d的校正死亡率最高达100％。不同有机溶剂的萃取物对杨树溃疡病原菌表现出抑制生长的作用,而对仙客来尖镰孢基本没有效果。     

Beneficial effect of Embelia ribes ethanolic extract on blood pressure and glycosylated hemoglobin in streptozotocin-induced diabetes in rats

Embelia ribes (common name, Vidanga) is extensively used in traditional system of medicine for treatment of various disorders. It is described in Ayurveda, as a powerful anthelmintic, antifertility and antihyperlipidemic agent. The present study was undertaken to investigate modulatory effect of 6 weeks' chronic oral administration of E. ribes ethanolic extract on diabetes mellitus induced by a diabetogen, streptozotocin (STZ) with special reference to changes in glucose levels, glycated haemoglobin status and cardiac toxicity. STZ treatment (40 mg/kg iv) resulted in significant increase in blood glucose levels, glycated haemoglobin levels, heart rate (HR) and systolic blood pressure (SBP). Oral administration of E. ribes ethanolic extract in dose of 100 mg/kg and 200 mg/kg significantly reduced the levels of blood glucose, glycated haemoglobin, heart rate (HR) and systolic blood pressure (SBP) in animals when compared with diabetic rats.     

Anti-hyperglycemic effect of Potentilla discolor decoction on obese-diabetic (Ob-db) mice and its chemical composition

Potentilla discolor is used as an ethnomedicine in treatments of diabetes mellitus in China for years. In the present study, the anti-hyperglycemic effects of a clinical active extract (decoction) from P. discolor were investigated in Ob-db mice. Four week's treatment of P. discolor decoction ameliorated the development of hyperlipidemia, lipid peroxidation and hyperglycemia associated with hyperphagia and polydypsia in Ob-db mice. P. discolor significantly attenuated the increase of blood glucose and cholesterol levels in Ob-db mice. These findings clearly provided evidences regarding the anti-hyperglycemic potentials of P. discolor decoction. High-resolution liquid chromatography-mass spectrometry/mass spectrometry (HR-LC-MS/MS) was used to analyze the phytochemicals in P. discolor decoction. In an comprehensive analysis of phytochemicals in P. discolor, thirty‐five components were identified or characterized in P. discolor decoction and only sixteen of them have been reported in P. discolor previously. There are five major components identified in P. discolor decoction. One of the major components is a flavonoid sulfate, and this is the first evidence for the presences of sulfated flavonoid in P. discolor. Sulfated flavonoids have been reported to improve the complications of diabetes mellitus by inhibition of the aldose reductase in both experimental animals and clinical trials. Therefore, the sulfated flavonoid in P. discolor decoction may in part contribute to the anti-hyperglycemic effect of P. discolor.     

黄花蒿提取物对菜蚜的杀虫活性研究

以丙酮、乙醇及水作溶剂，研究了黄花蒿全株干粉的3种溶剂提取物及其提取物不同浓度对菜蚜的触杀和胃毒活性。结果表明3种提取物对蚜虫都具有较强的毒杀活性，回归分析表明随着浓度升高杀虫时间缩短。LD50结果说明丙酮提取物的杀虫活性最强，乙醇提取物次之，最次是水提取物。独立样本t检验比较触杀效果和胃毒效果，表明黄花蒿各提取物均是触杀效果高于胃毒作用。     

Hypoglycemic and hypocholesterolemic activities of the aqueous leaf and seed extract of Phyllanthus amarus in mice

The effect of the aqueous leaf and seed extracts of Phyllanthus amarus at oral dose of 150, 300 and 600 mg/kg was investigated for their antidiabetic and anti-lipidemic potentials. The extract produced a dose-dependent decrease in the fasting plasma glucose and cholesterol, and reduction in weights in treated mice. The results suggest that the extract could be enhancing peripheral utilization of glucose but the mechanisms on how this works remain unclear.     

Bioactive plants from Argentina and Bolivia

Antibacterial and molluscicidal activities of methanol and chloroform extracts of 16 plant species belonging to the families Compositae and Melastomataceae were evaluated. The chloroform extract of Vernonanthura tweediana and the methanol extract of Senecio santelisis resulted to be very toxic to brine shrimp nauplii (LC(50)=1 microg/ml). Chloroform extracts of S. santelisis and Senecio leucostachys as well as the methanol extract of Wedelia subvaginata displayed molluscicidal effects on Biomphalaria peregrina showing LC(100)<100 microg/ml. Moderate antibacterial action was produced by the chloroform extracts of Flaveria bidentis, Grindelia scorzonerifolia and Vernonia incana against two strains of Staphylococcus aureus.     

Preliminary antiproliferative effects of some species of Terminalia, Combretum and Pteleopsis collected in Tanzania on some human cancer cell lines

Methanolic extracts (25 microug/ml) of species belonging to the genera of Combretum, Terminalia and Pteleopsis, collected during a field expedition in Tanzania in 1999, were screened for their antiproliferative and cytotoxic effects against three human cancer cell lines (HeLa, cervical carcinoma; T 24, bladder carcinoma; and MCF 7, breast carcinoma). A leaf extract of Combretum fragrans and a fruit extract of C. zeyheri gave the strongest antiproliferative and cytotoxic effects of all the twenty-four extracts screened in this investigation. In contrast to the highly powerful leaf extract of C. fragrans, the root extract of this species gave no cytotoxic effects against the investigated cancer cell lines at a concentration of 25 microg/ml. The other investigated species of Combretum and Terminalia differed greatly in their cytotoxic potential. Root extracts of Terminalia sambesiaca and T. sericea gave the strongest cytotoxic effects of the five species of Terminalia used in this study. Eight of the twenty-four investigated plant extracts showed pronounced cytotoxic effects (<30% proliferation compared to the control) against the T 24 bladder cancer cells, seven against the HeLa cells and four against the MCF 7 cells.     

Screening of medicinal and ornamental plants for insecticidal and growth regulating activity

Extracts of 121 medicinal and ornamental plants were screened for insecticidal and growth regulating activity to milkweed bug, Oncopeltus fasciatus Dallas. The most effective extracts stemmed from Inula helenium L., Rumex crispus L., R. acetosa L., Asarum europaeum L., and Calendula officinalis L. All these extracts exerted growth inhibiting activities and moderate or low acute toxicity. Most promising were extracts of dried roots of I. helenium. Besides a moderate chronic toxicity which reduced the fitness of the milkweed bug, the treatment produced overaged nymphs, supernumerary nymphs, disturbances of the moulting process, morphological defects, delay of adult maturation and reduction of fecundity. In addition, I. helenium extracts had a strong antifeedant effect when topically applied and very strong repellent effect when applied to the food (peeled sunflower kernels). It is obvious that the extract contains several active constituents. Such a cocktail may reduce the threat of rapid resistance development.