Antiangiogenic activities of polysaccharides isolated from medicinal fungi

Extracted polysaccharides from medicinal fungi, including Antrodia cinnamomea, Antrodia malicola, Antrodia xantha, Antrodiella liebmannii, Agaricus murrill, and Rigidoporus ulmarius, were investigated for their effects on vascular endothelial growth factor (VEGF)-induced tube formation in endothelial cells (ECs). Chemical analysis revealed that myo-inositol, sorbitol, fucose, galactosamine, glucosamine, galactose, glucose, and mannose were the neutral sugars in these polysaccharides. These fungal polysaccharides showed no toxicity to ECs. For the inhibition of endothelial tube formation, extracted polysaccharides from A. xantha and R. ulmarius were shown to produce greater inhibition compared to those from other fungi. Fucose, glucose and mannose were the predominant monosaccharides from these two fungi. These results suggest that monosaccharides may play a role in the inhibitory effect of these fungi on endothelial tube formation. In contrast to the inhibition on tube formation from polysaccharides of A. cinnamomea and A. malicola, polysaccharides from A. xantha and R. ulmarius, with molecular weight between 2693-2876 and 304-325 kDa, were critical for this inhibitory activity. Our results show that polysaccharides isolated from A. xantha and R. ulmarius provide greater antiangiogenesis than those from commercialized A. murrill (Brazilian mushroom) and A. cinnamomea. These studies provide a basis for the potential development of these polysaccharides for antiangiogenesis usage.     

Antiangiogenic properties of a sulfated galactan isolated from a marine green alga, Codium cylindricum

An anticoagulant sulfated galactan isolated from the marine green alga, Codium cylindricum, was shown to have antiangiogeinic activity. This galactan suppressed microvessel formation in an ex vivo serum-free matrix culture model using rat aortic ring. It also inhibited human umbilical vein endothelial cells (HUVEC) tube formation on reconstituted basement membrane gel. These results show the value of algal sulfated galactans in the design of antiangiogenic agents.     

Anti-angiogenic activity of julibroside J8, a natural product isolated from Albizia julibrissin

PurposeThe purpose of this study was to investigate the anti-angiogenic properties of julibroside J₈, a triterpenoid saponin isolated from Albizia julibrissin.MethodsIn the presence of juliborside J_8, the growth of human microvascular endothelial cells (HMEC-1), four human tumor cell lines, and a normal cell line (MRC-5) was evaluated by MTT assay. The in vivo anti-angiogenic effect of julibroside J₈ was evaluated on a chorioallantoic membrane (CAM) and in transplanted colon carcinoma cells in a nude mice neovascularisation model.ResultsTreatment with 0.5–4 μg/ml julibroside J₈ resulted in dose-dependent inhibition of growth, migration, and tube formation in HMEC-1 cells; julibroside J₈ also inhibited the formation of microvessels on CAM at a concentration of 10–50 μg/egg and reduced vessel density within tumor at a concentration of 0.5–3 mg/kg.ConclusionsJulibroside J₈ may be a potent anti-angiogenetic and cytotoxic drug; further investigation is warranted.     

Antiangiogenic properties of Koetjapic acid, a natural triterpene isolated from Sandoricum koetjaoe Merr

Background

Angiogenesis, the formation of new blood vessels, has become an important target in cancer therapy. Angiogenesis plays an important role in tumor growth and metastasis. Koetjapic acid (KA) is a seco-A-ring oleanene triterpene isolated from S. koetjape. The solvent extract of this plant species was shown previously to have strong antiangiogenic activity; however the active ingredient(s) that conferred the biological activity and the mode of action was not established. Given the high concentration of KA in S. koetjape, an attempt has been made in this study to investigate the antiangiogenic properties of KA.

Results

Treatment with 10-50 μg/ml KA resulted in dose dependent inhibition of new blood vessels growth in ex vivo rat aortic ring assay. KA was found to be non-cytotoxic against HUVECs with IC₅₀ 40.97 ± 0.37 μg/ml. KA inhibited major angiogenesis process steps, endothelial cell migration and differentiation as well as VEGF expression.

Conclusions

The non-cytotoxic compound, KA, may be a potent antiangiogenic agent; its activity may be attributed to inhibition of endothelial cells migration and differentiation as well VEGF suppression.     

Albendazole inhibits endothelial cell migration, tube formation, vasopermeability, VEGF receptor-2 expression and suppresses retinal neovascularization in ROP model of angiogenesis

The angiogenic process begins with the cell proliferation and migration into the primary vascular network, and leads to vascularization of previously avascular tissues and organs as well to growth and remodeling of the initially homogeneous capillary plexus to form a new microcirculation. Additionally, an increase in microvascular permeability is a crucial step in angiogenesis. Vascular endothelial growth factor (VEGF) plays a central role in angiogenesis. We have previously reported that albendazole suppresses VEGF levels and inhibits malignant ascites formation, suggesting a possible effect on angiogenesis. This study was therefore designed to investigate the antiangiogenic effect of albendazole in non-cancerous models of angiogenesis. In vitro, treatment of human umbilical vein endothelial cells (HUVECs) with albendazole led to inhibition of tube formation, migration, permeability and down-regulation of the VEGF type 2 receptor (VEGFR-2). In vivo albendazole profoundly inhibited hyperoxia-induced retinal angiogenesis in mice. These results provide new insights into the antiangiogenic effects of albendazole.     

VEGF,not VEGFR2, is associated with the angiogenesis effect of mini-TyrRS/mini-TrpRS in human umbilical vein endothelial cells in hypoxia

The purpose of this study was to determine the relationship between VEGF and mini-TyrRS/mini-TrpRS in angiogenesis in hypoxic culture and to begin to comprehend their mechanism in angiogenesis. We designed a VEGF gene silencing assay by using lentivirus vectors, and then western blotting was used to determine the protein expression of VEGF, VEGFR2 and pVEGFR2 in three groups in hypoxic culture at 3, 6, 12, or 24 h: (1) untransfected human umbilical vein endothelial cells (HUVECs) (Control); (2) pGCSIL-GFP lentivirus vector-transduced HUVECs (Mock); and (3) pGCSIL-shVEGF lentivirus vector-transduced HUVECs (Experimental). We also detected the effects of mini-TyrRS/mini-TrpRS peptides on HUVEC proliferation, migration and tube formation after lentivirus vector transfection and VEGFR2 antibody injection. The results indicated that expression of the mini-TyrRS protein was increased, whereas that of mini-TrpRS was specifically decreased in hypoxic culture both in control and mock groups. However, this trend in protein levels of mini-TyrRS and mini-TrpRS was lost in the experimental group after transduction with the pGCSIL-shVEGF lentivirus vector. The protein expression of VEGF was increased in hypoxic culture both in control and mock groups. After transduction with the pGCSIL-shVEGF lentivirus vector, the protein level of VEGF was noticeably decreased in the experimental group; however, for VEGFR2, the results showed no significant difference in VEGFR2 protein expression in any of the groups. For pVEGFR2, we found a distinct trend from that seen with VEGF. The protein expression of pVEGFR2 was sharply increased in hypoxic culture in the three groups. The addition of mini-TyrRS significantly promoted proliferation, migration and tube formation of HUVECs, while mini-TrpRS inhibited these processes in both control and mock groups in hypoxic culture. However, these effects disappeared after transduction with the pGCSIL-shVEGF lentivirus vector in the experimental group, but no significant difference was observed after VEGFR2 antibody injection. The protein expression of VEGF is similar to that of mini-TyrRS in hypoxic culture and plays an important role in the mini-TyrRS/mini-TrpRS-stimulated proliferation, migration and tube formation of HUVECs in hypoxia. These results also suggest that the change in mini-TyrRS and mini-TrpRS expression in hypoxic culture is not related to VEGFR2 and that some other possible mechanisms, are involved in the phosphorylation of VEGFR2.     

A novel endophytic Huperzine A–producing fungus,Shiraia sp. Slf14, isolated from Huperzia serrata

Aims: To characterize and identify a novel Huperzine A (HupA)‐producing fungal strain Slf14 isolated from Huperzia serrata (Thunb. ex Murray) Trev. in China. Methods and Results: The isolation, identification and characterization of a novel endophytic fungus producing HupA specifically and consistently from the leaves of H. serrata were investigated. The fungus was identified as Shiraia sp. Slf14 by molecular and morphological methods. The HupA produced by this endophytic fungus was shown to be identical to authentic HupA analysed by thin layer chromatographic, High‐performance liquid chromatography (HPLC), LC‐MS, ¹H NMR and acetylcholinesterase (AChE) inhibition activity in vitro. The amount of HupA produced by Shiraia sp. Slf14 was quantified to be 327·8 μg l^?1 by HPLC, which was far higher than that of the reported endophytic fungi, Acremonium sp., Blastomyces sp. and Botrytis sp. Conclusions: The production of HupA by endophyte Shiraia sp. Slf14 is an enigmatic observation. It would be interesting to further study the HupA production and regulation by the cultured endophyte in H. serrata and in axenic cultures. Significance and Impact of the Study: Although the current accumulation of HupA by the endophyte is not very high, it could provide a promising alterative approach for large‐scale production of HupA. However, further strain improvement and the fermentation process optimization are required to result in the consistent and dependable production.     

Inhibition of mitosis by avarol, a natural product isolated from the sponge Dysidea avara

Avarol, a sesquiterpenoid hydroquinone, is a cytostatic agent, isolated from the sponge Dysidea avara. Autoradiographic studies show that in vivo (L5178y mouse lymphoma cells) avarol changes the labelling index in favour of the fraction of unlabelled cells (from 1.24 to 1.04). At concentrations below the 50% inhibition dose, the mitotic index increases from 6.5 +/- 0.5 to 10.4 +/- 0.8; at higher concentrations the formation of mitotic figures is almost completely suppressed. In vitro studies applying the methods of viscosimetry and electron microscopy demonstrate that avarol inhibits assembly of brain microtubule protein at an at least stoichiometric concentration ratio. Moreover, evidence is presented that the new antimitotic agent avarol inhibits protofilament elongation rather than lateral association of tubulin during protofilament formation. The results suggest that avarol interferes with polymerization of tubulin both in interphase and during mitosis.     

安徽省三种产地竹黄菌培养的初步研究

首次对安徽省三种产地的竹黄菌进行了组织分离培养和液体发酵,比较了该菌固体生长状况和液体发酵形成的竹红菌素产量。结果显示,广德卢村的菌种平皿生长速度为0．31cm／d,液体发酵产生的竹红菌素吸光度为0．21;宁国板桥菌种平皿生长速度为0．30cm／d,液体发酵产生的竹红菌素吸光度为0．30;休宁武城的竹黄菌平皿生长速度为1．85cm／d,菌株液体发酵产生的竹红菌素吸光度为O．39。结论表明,休宁武城菌种无论是平皿生长速度还是发酵形成的竹红菌素量都明显优于其它两地的菌株。     

Imidazole,a new natural product from the leguminosae

Imidazole was isolated from Lens culinaris seeds as its dansyl derivative and shown to be identical to a synthetic standard by co-chromatography, ¹H NMR and EIMS. Chromatographic evidence indicated that it was also present in the seeds of 11 other legumes, 30% of those tested.     

Argovin,a novel natural product secreted by the fungus Meira argovae,is antagonistic to mites

A metabolite of the fungus Meira argovae Boekhout, Scorzetti, Gerson & Sztejnberg (Exobasidiomycetidae) was assayed as an antagonist of mites. Separation of extracted fungal metabolites by reversed phase liquid chromatography (RPLC), with subsequent testing of the obtained fractions, allowed us to isolate a single mite‐antagonistic fraction (also active against a bacterium) that primarily includes one major component. This active compound (herein termed ‘argovin’) was identified by analyzing its spectral characteristics as 4,5‐dihydroxyindan‐1‐one, which has previously only been described as a product of chemical reactions. The growth rate of the fungus was higher at a neutral pH than at an acidic one. Meira argovae adjusts the pH of its media to values optimal for its colony growth and toxic secretions. RPLC‐cleaned argovin at 0.2 mg ml^?1 killed 100% of a population of the citrus rust mite, Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae). This trait may be used to control citrus rust mites in the field, as well as for toxin production for industrial and pharmaceutical uses.     

Production of Taxol from Phyllosticta spinarum,an endophytic fungus of Cupressus sp.

Taxol production during the cultivation on a modified liquid and potato dextrose broth medium was indicated for the first time to occur in Phyllosticta spinarum, an endophytic fungus isolated from the needles of Cupressus sp. The presence of taxol in the fungal culture filtrate was confirmed by chromatographic and spectroscopic methods of analysis. The amount of taxol produced by this fungus was quantified by high performance liquid chromatography. The maximum amount of taxol production was obtained in this fungus when grown on M1D medium (235 μg/L) followed by PDB medium (125 μg/L). The results indicate that P. spinarum is an excellent candidate for taxol production . The production rate was 4.7 × 10³‐fold higher than that found in the culture broth of an earlier reported fungus, Taxomyces andreanae. The fungal taxol extracted also showed a strong cytotoxic activity in the in vitro culture of human cancer cells tested in an apoptotic assay.     

Punarnavine,an alkaloid from Boerhaavia diffusa exhibits anti-angiogenic activity via downregulation of VEGF in vitro and in vivo

Punarnavine, a quinolizidine alkaloid isolated from Boerhaavia diffusa is known to possess analgesic, anti-inflammatory, hepato-protective, immunomodulatory and anti-proliferative properties. However, its roles in tumor angiogenesis and the involved molecular mechanism are still unknown. Therefore, we examined its anti-angiogenic effects and mechanisms in vitro and in vivo. We examined the effect of punarnavine on VEGF-A expression by RT-PCR, Western blotting and ELISA. In vivo antiangiogenic activity was determined using sponge implant angiogenesis assay and antitumor activity was evaluated against Ehrlich ascites carcinoma tumor. Punarnavine significantly inhibited endothelial cell migration and invasion and capillary structure formation of HUVECs. Punarnavine significantly at 50 μM inhibited MMP-2 and MMP-9 expression in HUVECs in vitro. Punarnavine inhibited neovascularization in sponge implant assay. Punarnavine (15 mg/kg bw/d) treatment showed dose-dependent decrease in the ascitic fluid volume by 60.94% and tumor volume by 86.40% in Ehrlich ascites model. Reduction in peritoneal angiogenesis with punarnavine treatment suggests the anti-angiogenic activity of punarnavine. The present study sheds light on the potent anti-angiogenic of the punarnavine and can be extended further to develop therapeutic protocols for treatment of cancer.     

Cyanidin-3-glucoside, a natural product derived from blackberry, exhibits chemopreventive and chemotherapeutic activity

Epidemiological data suggest that consumption of fruits and vegetables has been associated with a lower incidence of cancer. Cyanidin-3-glucoside (C3G), a compound found in blackberry and other food products, was shown to possess chemopreventive and chemotherapeutic activity in the present study. In cultured JB6 cells, C3G was able to scavenge ultraviolet B-induced *OH and O2-* radicals. In vivo studies indicated that C3G treatment decreased the number of non-malignant and malignant skin tumors per mouse induced by 12-O-tetradecanolyphorbol-13-acetate (TPA) in 7,12-dimethylbenz[a]anthracene-initiated mouse skin. Pretreatment of JB6 cells with C3G inhibited UVB- and TPA-induced transactivation of NF-kappaB and AP-1 and expression of cyclooxygenase-2 and tumor necrosis factor-alpha. These inhibitory effects appear to be mediated through the inhibition of MAPK activity. C3G also blocked TPA-induced neoplastic transformation in JB6 cells. In addition, C3G inhibited proliferation of a human lung carcinoma cell line, A549. Animal studies showed that C3G reduced the size of A549 tumor xenograft growth and significantly inhibited metastasis in nude mice. Mechanistic studies indicated that C3G inhibited migration and invasion of A549 tumor cells. These finding demonstrate for the first time that a purified compound of anthocyanin inhibits tumor promoter-induced carcinogenesis and tumor metastasis in vivo.     

Chemical constituents from the rare mushroom Calvatia nipponica inhibit the promotion of angiogenesis in HUVECs

Calvatia species, also known as puffball mushrooms, are common sources of food worldwide. Calvatia nipponica (Agaricaceae) is one of the most rare species in the Calvatia genus. It was first validated in 2008. Due to its scarcity, C. nipponica has never been chemically investigated. Its recent discovery in Korea allowed to conduct this study, and using bioactivity-guided fractionation for antiangiogenic activity, chemical investigation of the MeOH extract of the fruiting bodies of C. nipponica led to the isolation of five alkaloids (1–5) and two phenolic compounds (6–7). This is the first study to report the chemical investigation of C. nipponica, and compound 1 was previously reported as chemically synthesized only until our report of its isolation and identification from natural sources. The structure of 1 was determined by spectroscopic analysis by 1D and 2D NMR spectra and HR-MS. All compounds (1–7) were tested for inhibition of angiogenesis using human umbilical vein endothelial cells (HUVECs). Compounds 2, 4 and 5 significantly inhibited the promotion of angiogenesis in HUVECs. Compound 5 showed the most potent inhibition via downregulation of VEGF, p38 and ERK signaling pathways. These results suggested that the rare mushroom C. nipponica might be beneficial in antiangiogenesis therapy for cancer treatment.     

Isolation, structure elucidation and biological activity of metabolites from Sch-642305-producing endophytic fungus Phomopsis sp. CMU-LMA

Eight polyketide compounds were isolated from the cultivation broth of Phomopsis sp. CMU-LMA. We have recently described LMA-P1, a bicyclic 10-membered macrolide, obtained as a bioconversion derivative of Sch-642305, the major compound isolated in this study. Benquinol is the ethyl ester derivative of the 13-dihydroxytetradeca-2,4,8-trienoic acid produced by Valsa ambiens. This compound is concomitantly produced with the 6,13-dihydroxytetradeca-2,4,8-trienoic acid (DHTTA) previously isolated from Mycosphaerellarubella. The absolute configuration of the new compound, (2R,3R,4S,5R)-3-hydroxy-2,4-dimethyl-5-[(S,Z)-3-methylpentenyl]-tetrahydro-pyranone LMA-P2 was confirmed by X-ray crystallography. The δ-lactone 2,3-dihydroxytetradecan-5-olide (DHTO) was previously isolated from Seiridium unicorne. This compound may form through the cyclization of the methyl-2,3,5-trihydroxytridecanoate LMA-P3, a new linear polyketide isolated in this study. Benquoine, a new 14-membered lactone generated from the cyclization of benquinol, is proposed as the key precursor for the biosynthesis of Sch-642305. Antimicrobial activity and cancer cell viability inhibition by the new compounds were investigated. Benquoine exhibits antimicrobial activity against Gram positive bacteria, and cytotoxicity against HCT-116 cancer cell line.     

Inhibition of protein kinase CKII activity by resveratrol,a natural compound in red wine and grapes

Resveratrol is a phytoalexin found in grapes and other foods that has been shown to have anticancer and anti-inflammatory effects. Because protein kinase CKII is involved in cell proliferation and oncogenesis, we examined whether resveratrol could modulate CKII activity. Resveratrol was shown to inhibit the phosphotransferase activity of CKII with IC(50) of about 10 microM. Steady state studies revealed that resveratrol acted as a competitive inhibitor with respect to the substrate ATP. A value of 1.2 microM was obtained for the apparent K(i). Resveratrol also inhibited the catalytic reaction of CKII with GTP as substrate. Furthermore, resveratrol inhibits endogenous CKII activity on protein substrates in HeLa cell lysates. These results suggest that resveratrol is likely to function by inhibiting oncogenic disease, at least in part, through the inhibition of CKII activity.     

Cytosporone S with antimicrobial activity,isolated from the fungus Trichoderma sp. FKI-6626

A new microbial metabolite, cytosporone S (1) was isolated from a fermentation broth of the fungus Trichoderma sp. FKI-6626. Its chemical structure was determined primarily by NMR spectroscopy and mass spectrometry. Compound 1 showed antimicrobial activity against several Gram-positive and Gram-negative bacteria and fungi.     

Antiangiogenic activity of 4-O-methylgallic acid from Canavalia gladiata, a dietary legume

Development of nontoxic and biologically safe antiangiogenic agent has been highlighted as a promising way to treat angiogenesis related diseases including cancer. Herein, we isolated 4-O-methylgallic acid (4-OMGA) from the seed of Canavalia gladiata, a dietary legume, on the basis of the growth inhibitory activity for bovine aortic endothelial cells (BAECs). The compound potently inhibits endothelial cell invasion and tube formation stimulated with basic fibroblast growth factor (bFGF) at low micromolar concentrations where it shows no cytotoxicity to the cells. In addition, 4-OMGA inhibits vascular endothelial cell growth factor (VEGF) production under hypoxic condition and the production of reactive oxygen species (ROS) in the endothelial cells stimulated with VEGF. These results demonstrate that 4-OMGA is a compound having potential for an antiangiogenic agent.