Inhibitory effects of compounds from Zingiberaceae species on platelet activating factor receptor binding

Ten compounds isolated from Alpinia mutica Roxb., Curcuma xanthorrhiza Roxb. and Kaempferia rotunda Linn. (Family: Zingiberaceae) were investigated for their platelet-activating factor (PAF) antagonistic activities on rabbit platelets using 3H-PAF as a ligand. Among them, four compounds showed significant inhibitory effects. Alpinetin and 5,6-dehydrokawain isolated from A. mutica exhibited IC50 values of 41.6 and 59.3 microM, respectively. The IC50 values of 3-deacetylcrotepoxide and 2-hydroxy-4,4',6'-trimethoxychalcone from K. rotunda were 45.6 and 57.4 microM, respectively. 1-Methoxy-2-methyl-5-(1',5'-dimethylhex-4'-enyl)-benzene, synthesized by methylation of xanthorrhizol which was obtained from C. xanthorrhiza, showed an IC50 value of 40.9 microM. The results indicated that these compounds were relatively strong PAF receptor binding inhibitors.     

Isolation of leishmanicidal triterpenes and lignans from the Amazonian liana Doliocarpus dentatus (dilleniaceae)

The in vitro antileishmanial activity of triterpenes and lignans of an Amazonian medicinal plant, Doliocarpus dentatus (Aublet) Standley, is reported for the first time against amastigotes of Leishmania amazonensis. Terpenes, for example, betulinic acid, betulin and betulinaldehyde were isolated by bioassay-linked extraction. The lignans were characterized as (+) pinoresinol, (+) medioresinol and (−) lirioresinol B.     

芦丁拮抗血小板活化因子与受体结合的作用

目的　观察芦丁对血小板活化因子(PAF)与受体结合的拮抗作用。方法　以放射配基结合试验观察[3H]PAF与家兔血小板受体特异性结合的作用;体外以分光光度法测定PAF介导血小板黏附的强度;以Fura- 2荧光分光光度法测定PAF介导的兔多形核白细胞(PMNs)内钙离子浓度的升高。结果　芦丁可浓度依赖地抑制1、2、4 nm ol/L [3H]PAF与血小板受体的特异性结合,其IC50 分别为7.3、8.7、17.2 mm ol/L ;芦丁可明显抑制PAF介导的血小板黏附,IC50 为1.5 1mm ol/L;芦丁浓度为6 8.2～5 4 6 μm ol/L 时可浓度依赖地抑制PAF介导的PMNs内游离钙浓度的升高。结论　芦丁具有抗PAF作用,为一种新的PAF受体拮抗剂。     

Evaluation of the cholinergic and adrenergic effects of two tropane alkaloids from Erythroxylum pervillei

Pervilleine A is an aromatic ester tropane alkaloid from Erythroxylum pervillei that has shown promising activity as a multidrug resistance inhibitor. Due to its structural similarity with the well known (-)-hyoscyamine and (-)-cocaine, the cholinergic and adrenergic activities of pervilleine A were evaluated. At 30 microm (+/-)-pervilleine A hydrochloride exhibited non-competitive inhibition of the cholinergic response in the guinea-pig ileum and did not affect the carbachol-induced contraction of the rat anococcygeus smooth muscle. (+/-)-Pervilleine A hydrochloride blocked nonspecifically the vascular response of (-)-norepinephrine in the rat aorta ring, while the contractile response of rat vas deferens to (-)-norepinephrine was not affected significantly at a 100 microm concentration. An analogue of pervilleine A, (+/-)-pervilleine H, without a 6-O-trans-3,4,5-trimethoxycinnamoyl ester substituent required for anti-multidrug resistance activity, did not exhibit any effects in these experiments. The data suggest that (+/-)-pervilleine A hydrochloride has weak nonspecific anticholinergic and vascular antiadrenergic activities. The lack of significant cholinergic and adrenergic receptor-mediated activities may be considered advantageous for the further development of pervilleine A as a new adjuvant in cancer chemotherapy.     

The Anti‐Osteoporosis and Antioxidant Activities of Chemical Constituents from Chrysanthemum indicum Flowers

Two new compounds, chrysinoneside A (1) and (?)‐trans‐chrysanthenol‐6‐O‐β‐D‐glucopyranoside (2), along with 17 known compounds (3–19) were isolated from Chrysanthemum indicum flowers. The total phenolic and flavonoid contents of various fractions were determined. The EtOAC fraction had the highest total phenolic content (525.84 ± 23.51 mg GAE/g DR) and the total flavonoid content (63.49 ± 3.32 mg QE/g DR). The EtOAc and water fractions showed the greatest peroxyl radical‐scavenging capacity and the ability to reduce Cu(I) ions, with ORAC and CUPRAC values ranging from 24.00 ± 0.44 to 28.06 ± 1.35 and 16.90 ± 0.51 to 49.77 ± 0.97 μM, respectively. Compounds 5–11, 18, and 19 displayed strong effects in both peroxyl radical‐scavenging and reducing capacity assays at a concentration of 10 μM. The anti‐osteoporosis activity of these compounds was also evaluated. Compounds 10, 13, and 19 exhibited the most potent tartrate‐resistant acid phosphatase activity in receptor activator of nuclear factor‐κB ligand‐induced osteoclastic RAW 264.7 cells with values of 105.95 ± 1.18, 110.32 ± 3.95, and 112.58 ± 6.42%, respectively. Copyright © 2015 John Wiley & Sons, Ltd.     

Angiogenic effect of saponin extract from Panax notoginseng on HUVECs in vitro and zebrafish in vivo

Angiogenesis plays an important role in a wide range of physiological processes such as wound healing and fetal development. In fact, many diseases are associated with imbalance in the regulation of angiogenesis in which there is either excessive or insufficient blood vessel formation. Panax notoginseng, a blood circulation invigorating herb, is commonly used in traditional Chinese medicine to treat circulation‐related diseases. However, the biological effects of saponin extract from Panax notoginseng (PNS) on angiogenesis and the underlying mechanisms are yet to be fully elucidated. This investigation describes the angiogenic effects of PNS on human umbilical vein endothelial cells (HUVECs) in vitro and zebrafish in vivo. The 2,3‐bis(2‐methoxy‐4‐nitro‐5‐sulfophenyl)5[(phenylamino)carbonyl]2H‐tetrazolium hydroxide (XTT) assay and microscopic cell counting demonstrated that the extract was able to stimulate the proliferation of HUVECs. Meanwhile, the numbers of invaded cells and tube branches were significantly increased in PNS treatment groups. PNS was also shown to promote changes in the subintestinal vessels, a feature of angiogenesis, in zebrafish. In addition, by using real‐time polymerase chain reaction (PCR), PNS was found to enhance vascular endothelial growth factor (VEGF) and kinase‐domain region/fetal liver kinase‐1 in mice (KDR/Flk‐1) mRNA expression, and the PNS‐induced HUVECs proliferation could be abolished by a KDR/Flk‐1 inhibitor. Furthermore, the proliferation of HUVECs induced by PNS was significantly attenuated by inhibitors of PI3K‐Akt‐eNOS. All the results suggest that PNS can promote angiogenesis, and that the proangiogenic effects involve the VEGF‐KDR/Flk‐1 and PI3K‐Akt‐eNOS signaling pathways. Copyright © 2008 John Wiley & Sons, Ltd.     

Effects of Ilex paraguariensis A. St. Hil. (yerba mate) on herpes simplex virus types 1 and 2 replication

The antiherpes effects of the crude extract obtained from Ilex paraguariensis leaves (yerba mate) and their purified fractions were investigated. The most active fraction was selected and assayed to determine the viral multiplication steps upon which it acted. In order to detect the major components of this fraction, thin layer chromatography (TLC) analysis was performed. The antiviral activity was evaluated against HSV-1 and HSV-2 by a viral plaque number reduction assay (IC(50) ) and the cytotoxicity by a MTT assay (CC(50) ). According to the obtained results, all tested samples showed antiherpes activity at noncytotoxic concentrations, and the ethyl acetate fraction was the most active (SI = CC(50) /IC(50) = 188.7 and 264.7 for HSV-1 and HSV-2, respectively). The results also demonstrated that this fraction exerts antiviral activity by the reduction of viral infectivity, the inhibition of virus entry into cells and cell-to-cell virus spread, as well as by the impaired levels of ICP27, ICP4, gD and gE proteins of HSV-1. The TLC analysis showed that this fraction contains monodesmosidic triterpenoid saponins, matesaponin-1 (a bidesmosidic one), caffeic and chlorogenic acids and rutin, which suggests that they could act synergistically and be responsible for the detected antiherpes activity.     

Identification of plant extracts with potential antidiabetic properties: effect on human peroxisome proliferator‐activated receptor (PPAR), adipocyte differentiation and insulin‐stimulated glucose uptake

Thiazolidinediones (TZDs) are insulin sensitizing drugs used to treat type 2 diabetes. The primary target of the TZDs is the peroxisome proliferator‐activated receptor (PPAR) γ, a key regulator of adipogenesis and glucose homeostasis. Currently prescribed TZDs are full PPARγ agonists, and their use is associated with several side effects. Partial PPARγ agonists appear to be associated with fewer side effects but may still confer the desired insulin sensitizing action. Extracts from common medicinal/food plants were tested in a screening platform comprising a series of bioassays, including tests for PPARγ, α and δ transactivation, adipocyte differentiation and insulin‐stimulated glucose uptake, allowing identification of plants containing potentially interesting PPAR agonists. Twenty‐two plant extracts out of 133 were found to increase insulin‐stimulated glucose uptake and 18 extracts were found to activate PPARγ, 3 to activate PPARα and γ, 6 to activate PPARδ and γ, and 9 to activate PPARγ, α and δ. Among the 24 different plant species tested in the platform, 50% were shown to contain compounds capable of activating PPARγ and stimulating insulin‐dependent glucose uptake with no or little effect on adipocyte differentiation warranting further studies and characterization. Copyright © 2009 John Wiley & Sons, Ltd.