Angiogenic signaling pathways and anti-angiogenic therapy for cancer.

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

The vascular protective effects of Anoectochilus roxburghii polysaccharose under high glucose conditions.

ETHNOPHARMACOLOGICAL RELEVANCE: Anoectochilus roxburghii has been used as a health food and a herb for treatment diabetes in China for hundreds years. Anoectochilus roxburghii polysaccharose (ARP) is the major active component of the plant. AIM OF THE STUDY: The present study investigated the vascular protection of ARP in vivo and in vitro experiments. MATERIALS AND METHODS: Hypoglycemic activity of ARP was examined in diabetic mice. Moreover, the further vascular protective effects in vitro were investigated in human umbilical vein endothelial cells (HUVECs) stimulated by high glucose (HG, 35mM). RESULTS: Compared with untreated diabetic mice, ARP (100 or 300mg/kg) caused a significant decrease in blood glucose levels. Histological examination showed that ARP ameliorated endothelial damage to some extent, especially ARP at dosage of 300mg/kg. In vitro assay, pretreatment with ARP (10, 20 and 30µg/mL) markedly inhibited generations of reactive oxygen species (ROS), monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) in HG-induced HUVECs. ARP pretreatment not only suppressed HG-induced matrix metalloproteinases (MMPs) activity via increasing the expression of the tissue inhibitors of MMPs (TIMPs), but also adjusted the MMPs/TIMPs balance to maintain homeostasis of vascular structure. Moreover, pretreatment with ARP could significantly reduce p-NF-κB p65, p-p38 MAPK expression levels in HG-induced HUVECs. CONCLUSIONS: The vascular protective effects of ARP might be associated with NF-κB and p38 MAPK pathway. ARP might be used as useful substance in the treatment of vasculopathy in diabetic patients.

Protection of kinsenoside against AGEs-induced endothelial dysfunction in human umbilical vein endothelial cells.

AIMS: Kinsenoside is the major ingredient of Anoectochilus roxburghii which is a traditional Chinese herb using for the treatment of diabetes. The present study investigated the safety and vascular protection of kinsenoside related to advanced glycation end products (AGEs) in human umbilical vein endothelial cells (HUVECs) and the underlying mechanisms. MATERIALS AND METHODS: HUVECs were pre-incubated with AGEs (200µg/mL) for 1h, and then co-treated with different concentrations of kinsenoside (10-30µg/mL) for another 48h. After the supernatant was collected, the contents of nitric oxide (NO), the levels of reactive oxygen species (ROS) and inflammatory cytokines, and the expressions of AGEs receptor (RAGE) and nuclear factor kappa B (NF-κB) were measured. KEY FINDINGS: No significant changes in cell viability were found in kinsenoside-treated cells at the range of 10-70µg/mL. Pretreatment with kinsenoside induced a significant increase in NO production in AGEs-induced cells. In addition, kinsenoside not only inhibited the expression of RAGE but also decreased intracellular ROS generation induced by AGEs. Furthermore, kinsenoside suppressed the protein and gene expression of NF-κB, and reduced the release of intercellular adhesion molecule-1 (ICAM-1) and human monocyte chemoattractant protein-1 (MCP-1) in a dose-dependent manner remarkably. SIGNIFICANCE: These results indicated that kinsenoside might attenuate AGEs-induced endothelial dysfunction via AGEs-RAGE-NF-κB pathway. Considering the relatively low toxicity of kinsenoside, it might be a promising agent for treatment of vasculopathy in diabetic patients.

Leaching heavy metals from the surface soil of reclaimed tidal flat by alternating seawater inundation and air drying.

Leaching experiments were conducted in a greenhouse to simulate seawater leaching combined with alternating seawater inundation and air drying. We investigated the heavy metal release of soils caused by changes associated with seawater inundation/air drying cycles in the reclaimed soils. After the treatment, the contents of all heavy metals (Cd, Pb, Cr, and Cu), except Zn, in surface soil significantly decreased (P < 0.05), with removal rates ranging from 10% to 51%. The amounts of the exchangeable, carbonate, reducible, and oxidizable fractions also significantly decreased (P < 0.05). Moreover, prolonged seawater inundation enhanced the release of heavy metals. Measurement of diffusive gradients in thin films indicated that seawater inundation significantly increased the re-mobility of heavy metals. During seawater inundation, iron oxide reduction induced the release of heavy metals in the reducible fraction. Decomposition of organic matter, and complexation with dissolved organic carbon decreased the amount of heavy metals in the oxidizable fraction. Furthermore, complexation of chloride ions and competition of cations during seawater inundation and/or leaching decreased the levels of heavy metals in the exchangeable fraction. By contrast, air drying significantly enhanced the concentration of heavy metals in the exchangeable fraction. Therefore, the removal of heavy metals in the exchangeable fraction can be enhanced during subsequent leaching with seawater.

The renal protective effects of Anoectochilus roxburghii polysaccharose on diabetic mice induced by high-fat diet and streptozotocin.

ETHNOPHARMACOLOGICAL RELEVANCE: Anoectochilus roxburghii (Wall.) Lindl. 1832 is an herbal medicine used to treat diabetes in China. Considering that Anoectochilus roxburghii polysaccharose (ARP) is the main constituent of Anoectochilus roxburghii, the present study is aimed to investigate the renal protection of ARP and its possible mechanism in diabetic mice. MATERIALS AND METHODS: Institute of Cancer Research (ICR) mice were induced to diabetes with high-fat diet (HFD) and low-dose streptozotocin (STZ). ARP (100, 300 mg/kg) was orally administrated to diabetic mice once a day for consecutive 15 days. The fasting glucose level, expressions of key proteins of p38 MAP kinase cascade, inflammatory factors, fibronectin (FN) and the activities of matrix metalloproteinases (MMPs) were measured. Furthermore, the histological examination of the separated kidneys was also carried out. RESULTS: Compared with the diabetic mice, ARP administration induced a significant decrease in blood glucose level and improved the body weight of diabetic mice. In addition, ARP inhibited the expression of renal p38 MAP kinase cascade and its downstream inflammatory factors including tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), FN as well as MMP2/9. Moreover, the histological examination showed an apparent reduction of mesangial matrix deposition and damage of microvascular structure after ARP administration. CONCLUSIONS: The protective effects of ARP on diabetic renal damage may be attributed to the inhibition of p38 MAP kinase cascade and then attenuating the inflammatory responses and high glucose-induced renal damage.

Antihyperglycemic activity of Anoectochilus roxburghii polysaccharose in diabetic mice induced by high-fat diet and streptozotocin.

ETHNOPHARMACOLOGICAL RELEVANCE: Anoectochilus roxburghii is a traditional Chinese herb used for treatment of diabetes and some other diseases. Anoectochilus roxburghii polysaccharose (ARP) is the main constituent of Anoectochilus roxburghii. The present study aimed to investigate the antidiabetic effects of ARP in diabetic mice induced by high-fat diet and streptozotocin. MATERIALS AND METHODS: Two doses of ARP (100 or 300 mg/kg) were administered once daily for 25 days to diabetic mice. To evaluate the antidiabetic effects of ARP, the fasting glucose levels, aspartate aminotransferase (AST), alanine transaminase (ALT) and superoxide dismutase (SOD) activities, malondialdehyde (MDA) content, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and liver glycogen were examined. Furthermore, histological examinations were carried out on the separated pancreas and liver of mice. RESULTS: Compared with untreated diabetic mice, ARP (100 or 300 mg/kg) caused a significant decrease in blood glucose levels, activities of AST and ALT, and MDA contents, and a significant increase in liver glycogen contents, SOD activities, thymus index and spleen index. Simultaneously, the alteration in lipid metabolism was partially attenuated as evidenced by decreased serum TC, TG and LDL-C concentrations in diabetic mice. In addition, histological examinations showed that administration of ARP (100 or 300 mg/kg) significantly attenuated the pathologic lesions in pancreas and liver of diabetic mice, and improved pancreas and liver function. CONCLUSIONS: The antidiabetic activity of ARP may be attributed to the improvement of glucose and lipid metabolism, increase of immune protection and reduction of oxidative stress.

The semisynthetic spin-labelled derivatives of 3-hydroxybutanolide as potential oxidative stress inhibitors.

To obtain more accessible oxidative stress inhibitors, a series of novel spin-labelled derivatives of 3-hydroxybutanolide (2a-d, 3a-d) with the natural active compound (kinsenoside) as the lead compound were designed, synthesised from the nitroxide free radical piperidine (pyrroline) and the main structural unit of kinsenoside: 3-hydroxybutanolide. Antioxidant activity screening of these derivatives was performed using MTT method on rat pheochromocytoma PC12 cells. The antioxidative stress effect was further investigated on the changes of the important antioxidant enzyme activities and intracellular reactive oxygen species production. Among the derivatives, 2b-d, 3a and 3c showed comparable or superior antioxidative stress activity to kinsenoside. Also, most of the tested derivatives displayed obvious antioxidative ability in concentrations. Cytotoxic assay simultaneously indicated that all compounds had very low toxicity to normal cells. Based on the observed results, the structure-activity relationship of these derivatives was discussed.

The vascular protective properties of kinsenoside isolated from Anoectochilus roxburghii under high glucose condition.

Anoectochilus roxburghii is a traditional Chinese herb used for the treatment of diabetes and some other diseases. The vascular protective effect of its major active ingredient, kinsenoside, in high glucose conditions was investigated in in vivo and in vitro experiments. In in vivo tests, kinsenoside (50 and 100mg/kg) efficiently lowered blood glucose and cholesterol levels and it enhanced the oxidation resistance of diabetic mice induced by streptozotocin. In the in vitro assay, kinsenoside (20 and 50 µg/mL) markedly inhibited changes in various biochemical substances (nitric oxide (NO), lactic dehydrogenase (LDH), superoxide dismutase (SOD), and catalase (CAT)) in human umbilical vein endothelial cells (HUVECs) damaged by high glucose (35 mM) and restored vascular endothelial structure by balancing the matrix metalloproteinases-the tissue inhibitors of matrix metalloproteinases (MMP-TIMP) system. The vascular protective effects of kinsenoside were speculated to be attributed to oxidative stress inhibition and the reduction of nuclear factor kappa B (NF-κB) mRNA expression levels in high glucose conditions. Moreover, histological examination, including hematoxylin-eosin (H&E) staining, masson trichrome (Masson) staining, and periodic Schiff-methenamine (PASM) staining, greatly supported the morphological and functional amelioration of diabetes-related changes in mice aortas after kinsenoside (20 and 50 µg/mL) treatment. These results indicated that kinsenoside might be a promising agent for the treatment of diabetic vascular disease.

Radical scavenging activity and cytotoxicity of active quinic acid derivatives from Scorzonera divaricata roots.

Five new quinic acid derivatives and two known 3-O-feruloylquinic acids were isolated from the roots of Scorzonera divaricata Turcz. The new compounds were elucidated as (-)-1,4-di-O-feruloyl-3-O-dihydrocaffeoylquinic acid, (-)-1-O-feruloyl-4-O- dihydrocaffeoylquinic acid, (-)-3,5-di-O-feruloylquinic acid, (-)-1-O-feruloyl-3-O-dihydro- caffeoylquinic acid, and (-)-1-O-feruloyl-5-O-dihydrocaffeoylquinic acid based on extensive spectroscopic studies, including one- and two-dimensional NMR, HRESIMS, UV, and IR results. Five compounds were assessed for antioxidant activity by ABTS and DPPH radical-scavenging assays and for their cytotoxicity against HL-60 and Hep-G2 cell lines by the MTT assay. Three quinic acid derivatives exhibited strong antioxidant activity, with IC(50) values of 3.95, 5.87, and 7.45 µg/mL against ABTS(+) and 11.7, 13.6, and 50.1 µg/mL against DPPH(). (-)-1,4-Di-O-feruloyl-3-O-dihydrocaffeoylquinic acid also exhibited moderate activity against Hep-G2 cell lines with an IC(50) value of 14.6 µg/mL.

Anti-HSV activity of camptothecin analogues.

In order to explore the range of biological activities of the camptothecin compound class, the in vitro antiviral efficacies of series I-IV of representative members from camptothecin analogues on herpes simplex virus type 2 (HSV-2) were evaluated on vero cells. Several compounds exhibited similar or better antiviral activity against HSV-2 in vitro than acyclovir. Among them, compound 6 showed the highest anti-HSV-2 activity, with IC(50) values of 1.3 microg mL(-1) and SI values of 27.04, respectively. On the basis of preliminary biological testing results, it is suggested that the intact E lactone ring and 20-hydroxy group should be not a prerequisite for camptothecin-like antiviral activity, and CPT substitution at the C-20 hydroxy group may be optimal for synthesising more potent antiviral compounds, suggesting that CPT has the potential to be a lead structure for semi-synthetic antiviral agents.

The phenylpropanoids of Aster flaccidus.

Aster flaccidus bge has been used as traditional medicine in northwestern China. Two new phenylpropanoids (1-2) including one lignan: (7'R, 8S)-9'-lariciresinol-(alpha-methyl)-butanoate (1), 5,9-dimethoxyl-7-(alpha-methyl)-butanoxyl-phenyl-2E-propenol-(alpha-methyl)-butanoate (2) isolated from the chloroform extract of the root of Aster flaccidus bge were identified by means of extensive spectroscopic studies: 1D and 2D NMR spectra as well as HRMS analysis. They have not obvious anti-HIV-1 therapeutic activity (TI=1.0-1.1) compared with AZT (TI=55,556) as the result of the determination of their in vitro anti-HIV-1 activity while compound 2 displays strong antitumor activity against BEL 7402 (human liver carcinoma) with cisplatin as a positive control and the effect increases with the measuring-time going on (24 h, IC(50): 106.67+/-8.47 microM - 72 h, IC(50): 50.51+/-6.11 microM).

HPLC-DAD and HPLC-ESI-MS separation, determination and identification of the spin-labeled diastereoisomers of podophyllotoxin.

Spin-labeled nitroxide derivatives of podophyllotoxin had better antitumor activity and less toxicity than that of the parent compounds. However, the 2-H configurations of these spin-labeled derivatives cannot be determined by nuclear magnetic resonance (NMR) methods. In the present paper, a high-performance liquid chromatography-diode array detection (HPLC-DAD) and a high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI/MS/MS) method were developed and validated for the separation, identification of four pairs of diastereoisomers of spin-labeled derivatives of podophyllotoxin at C-2 position. In the HPLC-ESI/MS spectra, each pair of diastereoisomers of the spin-labeled derivatives in the mixture was directly confirmed and identified by [M+H](+) ions and ion ratios of relative abundance of [M-ROH+H](+) (ion 397) to [M+H](+). When the [M-ROH+H](+) ions (at m/z 397) were selected as the precursor ions to perform the MS/MS product ion scan. The product ions at m/z 313, 282, and 229 were the common diagnostic ions. The ion ratios of relative abundance of the [M-ROH+H](+) (ion 397) to [M+H](+), [A+H](+) (ion 313) to [M-ROH+H](+), [A+H-OCH(3)](+) (ion 282) to [M-ROH+H](+) and [M-ROH-ArH+H](+) (ion 229) to [M-ROH+H](+) of each pair of diastereoisomers of the derivatives specifically exhibited a stereochemical effect. Thus, by using identical chromatographic conditions, the combination of DAD and MS/MS data permitted the separation and identification of the four pairs of diastereoisomers of spin-labeled derivatives of podophyllotoxin at C-2 in the mixture.

[Study on steroids of Cacalia tangutica].

Seven steroids and two cumarins were isolated from the petroleum ether extract of the specie Cacalia tangutica of the family Compositae which were collected in Minhe county, Qinhai province of China. The structures were identified as Stigmast4-en-3beta, 6beta-diol (1), 24-ethyl-5alpha-cholestane-3beta, 5, 6beta-triol (2), 7beta- methoxy-stigmast-5-en-3beta-ol (3), Schleicherastatin 1 (4), Stigmast-5-en-3beta, 7alpha-diol (5), umbelliferone (6) and hydrangetin (7) by the means of chemical and modern spectroscopic analysis (MS, 1H-NMR, 13C-NMR, DEPT). The compounds 1-5 were isolated from Cacalia tangutica for the first time.

[Phenolic components from Rhodiola dumulosa].

Eight phenolic compounds (1-7) were isolated from the methanol extract of the root of Rhodiola dumulosa. Their structures were identified as kaemperol (1), Quercetin (2), Gallic acid (3), (+) -Isolariciresinol-3alpha-O-beta-D-glucopyranoside (4), (-)-Isolariciresinol-3alpha-O-beta-D-glucopyra-noside (5), kaemperol-3-O-beta-D-glucopyranoside-7-alpha-O-L-rhamnoside (6), rutin (7) respectively on the basis of chemical and spectroscopic evidence. The compounds 3-7 were isolated from R. dumulosa for the first time.

Six new sesquiterpenes from Euonymus nanoides and their antitumor effects.

Six new dihydro-beta-agarofuran [5,11-epoxy-5beta,10alpha-eudesm-4 (14)-ene] sesquiterpenes were isolated from the seeds of Euonymus nanoides Loes, including five with a novel substitution pattern: (1 R,2 S,4 S,5 R,7 R,9 S,10 R)-1alpha-benzoyloxy-2alpha,15-diacetoxy-4beta-hydroxy-9beta-cinnamoyloxy-beta-dihydroagarofuran ( 1), 1alpha-(alpha-methyl)-butanoyl-2alpha,15-diacetoxy-4beta-hydroxy-9beta-(beta-)furoyloxy-beta-dihydroagarofuran ( 2), 1alpha,2alpha-di-(alpha-methyl)-butanoyl-4beta-hydroxy-9beta-(beta-)furoyloxy-15-acetoxy-beta-dihydroagarofuran ( 3), 1alpha-(alpha-methyl)-butanoyl-2alpha-(alpha-methyl)-propynoyloxy-4beta-hydroxy-9beta-(beta-)furoyloxy-15-acetoxy-beta-dihydroagarofuran ( 4) and 1alpha,2alpha, 9beta-tri-(beta-)furoyloxy-4beta-hydroxy-15-acetoxy-beta-dihydroagarofuran ( 5). The other dihydroagarofuran sesquiterpene was 1alpha,2alpha,6beta,15-tetraacetoxy-3alpha-(alpha-methyl)-butanoyl-4beta-hydroxy-9beta-(beta-)furoyloxy-beta-dihydroagarofuran ( 6). The structures of 1 - 6 were elucidated by means of (1)H- and (13)C-NMR spectroscopic studies, including 2D heteronuclear COSY (HMQC), long-range correlation spectra with inverse detection (HMBC), (1)H- (1)H COSY and NOESY. The absolute configuration of compound 1 was determined by application of the CD exciton chirality method. Six compounds were evaluated for their in vitro antitumor effects (IC (50) values: 27.71 - 50.69 microg/mL) and the structure-activity relationship is discussed.