Combined therapy using bevacizumab and turmeric ethanolic extract (with absorbable curcumin) exhibited beneficial efficacy in colon cancer mice.

Turmeric is commonly used as a medicinal herb and dietary supplement. Its active ingredient, curcumin, has been shown to possess antitumor effects in colorectal cancer patients. However, poor absorption of curcumin in intestine impedes its wide clinical application. Our previous findings showed that the presence of turmerones increased the accumulation of curcumin inside colonic cells. Hence, we hypothesized that curcumin with turmerones or present in turmeric ethanolic extract would augment its anti-tumor activities in tumor-bearing mice. The pharmacokinetics of curcumin in different preparations (containing same amount of curcumin) were studied in mice. The anti-tumor efficacies of curcumin or turmeric extract (with absorbable curcumin) in combination with bevacizumab were further investigated in HT29 colon tumor-bearing mice. Pharmacokinetic results showed that the plasma curcumin level of turmeric extract-fed mice was the highest, suggesting turmeric extract had the best bioavailability of curcumin. Besides, combined turmeric extract plus bevacizumab treatment significantly inhibited the tumor growth. Such inhibitory effects were stronger than those of curcumin plus bevacizumab or bevacizumab alone and were comparable with those of 5-fluorouracil+leucovorin+oxaliplatin (FOLFOX) plus bevacizumab. Notably, there was no observable side effect induced by turmeric extract treatment while significant side effects were found in FOLFOX-treated mice. In conclusion, combination of turmeric extract with bevacizumab possessed potent anti-tumor effects without observable side effects, strongly suggesting the adjuvant use of turmeric extract in colorectal cancer therapy. Our current findings warrant the confirmation regarding the benefits arising from the combined use of bevacizumab and turmeric in colorectal cancer patients in the near future.

Anti-angiogenic activity of Herba Epimedii on zebrafish embryos in vivo and HUVECs in vitro.

Herba Epimedii, an herb commonly used in East Asian medicine, is commonly used for treatment of impotence, osteoporosis and many inflammatory conditions in traditional Chinese medicine. Recent studies revealed that Herba Epimedii also has anti-tumor or anti-cancer activities, which may possibly be mediated through anti-angiogenesis. This study aims to examine and confirm the anti-angiogenic activity in the herb using both in vivo and in vitro approaches. The 95% ethanol extract and four subsequent fractions (n-hexane, ethyl acetate (EA), n-butanol and aqueous fractions) of Herba Epimedii were tested on the zebrafish model by the quantitative assay for endogenous alkaline phosphatase; then, the active fraction was further tested on Tg(fli1a:EGFP)y1 zebrafish embryos and human umbilical vein endothelial cells (HUVECs) for the anti-angiogenic effects. In addition, the action mechanism of Herba Epimedii was further investigated on wild-type zebrafish embryos and HUVECs. The EA fraction showed anti-angiogenic effects in both in vivo and in vitro models. Further experiments demonstrated that it might affect angiogenesis by acting on multiple molecular targets in zebrafish embryos and ERK signaling pathway in HUVECs. In conclusion, Herba Epimedii can inhibit angiogenesis, which may be the mechanism for its anti-inflammatory, anti-tumor and anti-cancer actions.

Anti-angiogenic activity of Erxian Decoction, a traditional Chinese herbal formula, in zebrafish.

Erxian Decoction (EXD), a traditional Chinese herbal formula, has been used to treat menopausal symptoms and other aging diseases for several decades. Recently, our laboratory found that EXD could inhibit the proliferation of breast cancer cells. This activity may be mediated by anti-angiogenic action. To investigate the anti-angiogenic activity of EXD, its inhibitory effect on blood vessel formation was evaluated using both wild type and transgenic zebrafish embryos with fluorescent vasculature in vivo. Both semi-quantitative and real-time quantitative polymerase chain reaction (qPCR) were carried out to evaluate the effect of EXD on the expression of several genes closely associated with angiogenesis in zebrafish. EXD was found to inhibit vessel formation in zebrafish embryos in a dose- and time-dependent manner. Furthermore, it reduced the mRNA expression of vascular endothelial growth factor A (VEGF-A) and the protein level of hypoxia inducible factor 1α (HIF-1α) in the embryos, suggesting the involvement of HIF-1 mediated VEGF-A signaling pathway in the anti-angiogenic action of EXD. The anti-angiogenic activity of EXD provides new insights to its clinical application and may in the future lead to the development of potential drugs for treating various cancers, especially in menopausal period.

Screening for anti-inflammatory and bronchorelaxant activities of 12 commonly used Chinese herbal medicines.

The use of health supplements derived from medicinal herbs as self-medication for the relief of respiratory tract pathology symptoms is increasing in Chinese communities as air pollution is worsening. Twelve herbs from two formulae of our previous studies were evaluated for their anti-inflammatory, immunomodulatory and bronchorelaxant activities in this study. Among the extracts tested, those of Herba Schizonepetae and Radix Glycyrrhizae showed significant inhibitory effects on LPS-induced nitric oxide production (p < 0.05) in mouse macrophage RAW264.7 cells, suggesting their anti-inflammatory activities. Radix Scutellariae and Radix Glycyrrhizae extracts showed significant inhibitory effects on phytohaemagglutinin-induced proliferation in human peripheral blood mononuclear cells (p < 0.05). These extracts also showed inhibition of TNF-α, IFN-γ and IL-10 production. For the bronchorelaxant assay, Rhizoma Cynanchi Stauntonii and Radix Glycyrrhizae extracts showed potent attenuation of the acetylcholine- and carbachol-induced contractions in rat trachea (p < 0.05), implying their relaxant activities. In conclusion, Herba Schizonepetae, Radix Glycyrrhizae, Radix Scutellariae and Rhizoma Cynanchi Stauntonii extracts were demonstrated to exert anti-inflammatory, immunomodulatory and bronchorelaxant activities, which may help to ameliorate the symptoms of respiratory tract pathologies. The findings have thus provided some scientific evidence on the efficacy and mechanisms of action of these herbs, which are useful for the further development of clinical applications.

Natural flavone tricin exerted anti-inflammatory activity in macrophage via NF-κB pathway and ameliorated acute colitis in mice.

BACKGROUND: Ulcerative colitis is a subtype of inflammatory bowel disease, characterized by relapsing inflammation in the gastrointestinal tract with limited treatment options. Previous studies suggested that the natural compound tricin, a flavone isolated from rice bran, could suppress chemically-induced colitis in mice, while our recent study also demonstrated the anti-metastatic effect of tricin in colon tumor-bearing mice. HYPOTHESIS/PURPOSE: Here we further investigated the underlying mechanism of the inhibitory effects of tricin on lipopolysaccharides-activated macrophage RAW264.7 cells and explored the efficacy of tricin in acute colitis mouse model induced by 4.5% dextran sulfate sodium (DSS) for 7 days. METHODS: Tricin (75, 100, and 150 mg/kg) or the positive control drug sulfasalazine (200 mg/kg) were orally administered to mice for 7 days. Stool consistency scores, stool blood scores, and body weight were recorded daily. Disease activity index (DAI) was examined on day 7, and colon tissues were collected for biochemical analyses. The fecal microbiome of colitis mice after tricin treatment was characterized for the first time in this study using 16S rDNA amplicon sequencing. RESULTS: Results showed that tricin (50 µM) remarkably reduced nitric oxide production in lipopolysaccharides-activated RAW264.7 cells and the anti-inflammatory activity of tricin was shown to act through the NF-κB pathway. Besides, tricin treatment at 150 mg/kg significantly reversed colon length reduction, reduced myeloperoxidase activities and DAI scores, as well as restored the elevated myeloid-derived suppressive cells population in acute colitis mice. The influence from DSS on gut microbiota, such as the increased population of Proteobacteria phylum and Ruminococcaceae family, was shown to be relieved after tricin treatment. CONCLUSION: Our present study firstly demonstrated that tricin ameliorated acute colitis by improving colonic inflammation and modulating gut microbiota profile, which supports the potential therapeutic use of tricin for colitis treatment.

Immunomodulatory and antitumour bioactive labdane diterpenoids from Leonurus japonicus.

OBJECTIVES: Two labdane diterpenoids, leojapone B and heteronone B, were isolated from Leonurus japonicus Houtt., and their biological activity were evaluated in this study. METHODS: Human and mouse cancer cells, human peripheral blood mononuclear cells (PBMCs) and mouse macrophages (RAW264.7 cells) were used to evaluate the activity of leojapone B and heteronone B, while the in vivo effects of leojapone B were further examined in Lewis Lung Cancer tumour-bearing mice. KEY FINDINGS: In vitro studies showed that leojapone B selectively inhibited the proliferation of lung cancer cells, and both leojapone B and heteronone B inhibited the production of pro-inflammatory cytokines in activated PBMCs. In tumour-bearing mice model, lung tumours were reduced in size in mice treated with intraperitoneal injections of leojapone B at 20 and 30 mg/kg for 14 days. The population ratio of CD4+ /CD8+ T cells in mouse spleens was found to be increased, while regulatory T cells were decreased after leojapone B treatment. CONCLUSIONS: The inhibitory effects of leojapone B in mouse lung tumours were demonstrated for the first time in this study. The immunomodulatory activity of heteronone B were also demonstrated. Our findings indicated that both leojapone B and heteronone B may act as active components in L. japonicus.

A review on the immunomodulatory activity of Acanthopanax senticosus and its active components.

Acanthopanacis Senticosi Radix et Rhizoma seu Caulis, the dried root and rhizome or stem of Acanthopanax senticosus, is commonly known as Siberian ginseng or Ciwujia in Chinese. It is used all over the world as an adaptogen to enhance physical and mental performance for the sake of normal physiological functioning of human bodies under stress. In the theory of traditional Chinese medicine, Ciwujia can strengthen the spleen that is an essential organ for immunological response. Its traditional applications include inflammation, fatigue and cancer in which the immune-regulating function is always involved. In this article, the immunomodulatory activities of Ciwujia extracts, fractions and pure compounds were extensively reviewed first. Then, the possibility of upgrading the chemical markers to bioactive markers was explored. Finally, the potency of aqueous extract and ethanol extract in regulating cytokines production from human peripheral blood mononuclear cells was compared. We conclude that although various phytochemicals such as isofraxidin, syringin and eleutheroside E from Ciwujia have been shown to modulate immunological functions, the aqueous extract of Ciwujia as a whole possesses the most potent efficacy. Therefore, aqueous (rather than ethanol) extract of Ciwujia should be used in order to benefit from its immunomodulatory properties.

Method establishment for upgrading chemical markers in pharmacopoeia to bioactive markers for biological standardization of traditional Chinese medicine.

Quality surveillance on authentication, safety and efficacy of proprietary Chinese medicines (pCm) are certainly the top priorities for the industries. Nowadays, the quality control system adopted is mainly chemical marker-oriented, concerning basically the correct use of raw material and safety issues, while the biological activities of the chemical marker(s) are seldom considered. Hence, there is an undefined relationship between the amount of chemical markers and the claimed pharmacological activities. In view of the need in identifying appropriate markers for biological standardization of pCm products, the present study aimed to establish a systematic methodology for verifying whether the chemical marker of a traditional Chinese medicine (TCM) listed in Chinese Pharmacopoeia could be upgraded to a bioactive marker with certain efficacy in treating a particular disease. Our proposed methodology included a series of work on extraction, quantification, literature search and in vivo pharmacological experiments, in which the water extractability, biological effects at theoretical dose and oral bioavailability of the candidate chemical markers were all taken into consideration. The feasibility and implication of this bioactive markers verification methodology were further elaborated. Our findings will serve as the foundation for further research and development of biological standardization of TCM.

Multiple modulatory activities of Andrographis paniculata on immune responses and xenograft growth in esophageal cancer preclinical models.

BACKGROUND: Esophageal cancer (EC) is a malignant gastrointestinal cancer with high morbidity worldwide and is the fourth leading cause of cancer-related deaths in China. Even though surgery and/or chemotherapy/chemoradiation might achieve good therapeutic response, recurrence rate is high due to cancer metastasis. Hence, the use of alternative adjuvant treatments, such as herbal medicines, for metastatic EC remains a great desire of the patients. Our previous studies have demonstrated the anti-metastatic efficacy of hot water extract of Andrographis paniculata (APW) in human esophageal cancer cells and tumor-bearing nude mice. PURPOSE: In the present study, the immunomodulatory activities of APW were further evaluated in human peripheral blood mononuclear cells (PBMCs) and in a carcinogen-induced esophageal tumorigenesis model using immune-competent C57BL/6 mice. Besides, the inhibitory effects of APW on esophageal cancer cell line-based xenografts and patient-derived xenografts (PDX) were examined so as to illustrate the potential multi-targeted efficacies of APW in esophageal cancer in pre-clinical models. RESULTS: In vitro results showed that APW could stimulate proliferation of PBMCs, as well as TNF-α and IFN-γproductions. In mice with 4-nitroquinoline 1-oxide-induced tumorigenesis, 21-day oral treatment with APW (1600 mg/kg) decreased the level of dysplasia in esophagus and significantly modulated the population of regulatory T cells. The cytokines productions by spleen lymphocytes of APW-treated mice were shifted towards normal resting state (i.e. unchallenged with carcinogen). Furthermore, APW treatment suppressed the growth of cell line-based xenografts by significantly increasing apoptosis in tumors, without causing severe body weight loss as chemotherapeutics did. Most importantly, the inhibitory effects of APW treatment on esophageal patient-derived xenografts growth were demonstrated for the first time. Besides, several diterpenes were detected in the plasma after oral administration of APW in mice, suggesting that multi-components of APW were bioavailable and might have contributed towards the varied pharmacological activities demonstrated in our studies. CONCLUSION: APW was shown to possess anti-tumor, anti-metastatic and immunomodulatory activities in esophageal cancer cell-based and animal models, including immunocompromised mice model and clinically relevant PDX model. Our findings illustrated the potential multi-targeted efficacies of APW in esophageal cancer management.

An innovative anti-cancer Chinese herbal formula exhibited multi-targeted efficacies in metastatic breast cancer mouse model.

BACKGROUND: The incidence and mortality of cancer metastasis is high worldwide. Despite of the chemotherapeutic agents, many cancer patients still take traditional Chinese herbal prescriptions as adjuvant treatments. However, most of these herbal formulae/products lack of evidence-based efficacy. Based on our previous investigations on anti-tumor, anti-angiogenic, anti-metastatic, bone protective and immunomodulating activities of various Chinese herbal medicines, four constituent herbs, namely Andrographis paniculata, Acanthopanax senticosus, Camellia sinensis, and Hedyotis diffusa were eventually selected to form an innovative herbal formula. METHODS: The anti-tumor efficacies of the formula were evaluated in metastatic breast cancer mice model. The bone protective and immunomodulatory effects were also assessed after formula treatment. RESULTS: Our results showed that the breast tumor weight as well as lung and liver metastasis in mice could be reduced after herbal formula treatment for 4 weeks. The breast tumor-induced osteolysis in mice was restored by herbal formula treatment, in which the bone volume in treated mice tibia was comparable to that in the non-tumor bearing normal mice. The IL-12 level was augmented and the survival of mice with metastatic breast tumors was prolonged after treatment. Furthermore, combination of herbal formula with chemotherapeutic agent doxorubicin resulted in better anti-tumor efficacy and increased life span in tumor-bearing mice, when compared with doxorubicin alone treatment. CONCLUSIONS: In summary, our innovative Chinese herbal formula was demonstrated to possess anti-tumor, anti-metastatic and bone-protective activities in metastatic breast tumor-bearing mice. The preclinical data generated in this study would lead to the development of evidence-based supplement as adjuvant therapy for metastatic breast cancer.

Using Ultra-Performance Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry-Based Chemometrics for the Identification of Anti-angiogenic Biflavonoids from Edible Garcinia Species.

Garcinia xanthochymus fruits are edible and also used in traditional medicine. Our previous work showed that the isolated natural products from G. xanthochymus fruits have displayed antioxidant activity and cytotoxicity in the colon cancer cells. In this study, we developed a strategy to correlate a zebrafish angiogenesis assay with ultra-performance liquid chromatography quadrupole time of flight mass spectrometry-based chemometric analysis to identify potential anti-angiogenic activity compounds from G. xanthochymus fruits. Primary bioactivity results showed that the methanolic extracts from aril and pericarp but not from seed have significant inhibitory effects on the growth of subintestinal vessels (SIVs) in zebrafish embryos. A total of 13 markers, including benzophenones and biflavonoids, were predicted by untargeted principal component analysis and orthogonal partial least squares discriminate analysis, which were tentatively identified as priority markers for the bioactivity related in aril and pericarp. Amentoflavone, a biflavonoid, has been found to significantly inhibit the growth of SIVs at 10 and 20 µM and downregulate the expressions of Angpt2 and Tie2 genes of zebrafish embryos. Furthermore, seven biflavonoids, volkensiflavone, fukugetin, fukugeside, GB 1a, GB 1a glucoside, GB 2a, and GB 2a glucoside, isolated from Garcinia species were evaluated for their structure-activity relationship using the zebrafish model. Only fukugetin, which was previously shown to be anticancer, was active in inhibiting the SIV growth. In this report, both amentoflavone and fukugetin, for the first time, displayed anti-angiogenic effects on zebrafish, thus demonstrating an effective and rapid strategy to identify natural products for anti-angiogenesis activity.

Whole extracts of Radix Achyranthis Bidentatae and Radix Cyathulae promote angiogenesis in human umbilical vein endothelial cells in vitro and in zebrafish in vivo.

Although Radix Achyranthis Bidentatae (RAB) and Radix Cyathulae (RC) are from two different medicinal plants, they are both used as 'Niu-Xi', a widely used traditional Chinese medicine that is believed to stimulate menstruation and affect bone injury. Angiogenesis is actively involved in treating these illnesses. The aim of the present study was to investigate whether the whole extracts of RAB and RC possess pro-angiogenic effects. In order to examine this idea whole extracts of RAB and RC were extracted with boiling water followed by ethanol, respectively. Results from the MTT, wound healing and tube formation assays in human umbilical vein endothelial cells (HUVECs) in vitro revealed that the whole extracts of RAB and RC did not increase cell proliferation or tube formation, but enhanced cell migration. Their angiogenic effects were also confirmed in zebrafish in vivo via increasing the sprout numbers in the sub-intestinal vessel. As determined by quantitative polymerase chain reaction, the whole extracts of RAB and RC both regulated the expression of cell migration-related genes in zebrafish. It is concluded that the whole extracts of RAB and RC induced angiogenesis in HUVECs in vitro and in zebrafish in vivo via increasing cell migration.

Anti-angiogenic Activity and Mechanism of Sesquiterpene Lactones from Centipeda minima.

Centipeda minima is a Chinese herbal medicine used in the treatment of various diseases including cancer. An ethanol extract of the herb, its four fractions with different polarities, and two volatile oils prepared by steam distillation (SD) and supercritical fluid extraction (SFE) were investigated for their anti-angiogenic activity in a wild-type zebrafish model using a quantitative endogenous alkaline phosphatase (EAP) assay. The SFE oil displayed potent anti-angiogenic activity. Fifteen sesquiterpene lactones (SLs; compounds 1-15) isolated from the SFE oil were evaluated for their anti-angiogenic effect. Results revealed that pseudoguaianolide type SLs (1-8) inhibited vessel formation in the zebrafish embryos while guaianolide type SLs (9-15) showed little effect. Among the active ones, 6-O-angeloylenolin (1), a major component of SFE oil, possessed the strongest effect by reducing vessel formation in zebrafish embryos to 40% of the control value at 29.7 µM. Further study using the Tg (fli1a:EGFP) y1-type zebrafish model revealed that it blocked both intersegmental blood vessels (ISVs) and subintestinal vessels plexus (SIVs) formation in zebrafish embryos. Real-time polymerase chain reaction assay on the wild-type zebrafish embryos suggested that 6-O-angeloylenolin affected multiple molecular targets related to angiogenesis including VEGF receptor, angiopoietin, and its receptors. Taken together, our findings demonstrate that C. minima possesses anti-angiogenic activity, and 6-O-angeloylenolin is a promising candidate for the development of an anti-angiogenic agent.

New potential beneficial effects of actein, a triterpene glycoside isolated from Cimicifuga species, in breast cancer treatment.

Actein is a triterpene glycoside isolated from the rhizomes of Cimicifuga foetida (Chinese herb "shengma") which could inhibit the growth of breast cancer cells. Nevertheless, the effect of actein on angiogenesis, which is an essential step for tumor growth and metastasis, has never been reported. Hence, this study aimed to investigate the in vitro and in vivo effects of actein on angiogenesis using human microvascular endothelial cells (HMEC-1), matrigel plug and tumor-bearing mouse models. Our results showed that actein significantly inhibited the proliferation, reduced the migration and motility of endothelial cells, and it could suppress the protein expressions of VEGFR1, pJNK and pERK, suggesting that JNK/ERK pathways were involved. In vivo results showed that oral administration of actein at 10 mg/kg for 7 days inhibited blood vessel formation in the growth factor-containing matrigel plugs. Oral actein treatments (10-15 mg/kg) for 28 days resulted in decreasing mouse 4T1 breast tumor sizes and metastasis to lungs and livers. The apparent reduced angiogenic proteins (CD34 and Factor VIII) expressions and down-regulated metastasis-related VEGFR1 and CXCR4 gene expressions were observed in breast tumors. Our novel findings provide insights into the use of actein for development of anti-angiogenic agents for breast cancer.

Enumeration and functional investigation of endothelial progenitor cells in neovascularization of diabetic foot ulcer rats with a Chinese 2-herb formula.

BACKBROUND: We investigated the effect of a Chinese 2-herb formula (NF3) on the enumeration and angiogenic differentiation of endothelial progenitor cells (EPCs) in diabetic foot ulcer rats. METHODS: EPCs and stromal cell-derived factor-1α (SDF-1α) were quantified by flow cytometry and ELISA, respectively. In vitro angiogenesis assays included proliferation, adhesion, migration and tube formation. RESULTS: Our result demonstrated that NF3 (0.98 g/kg) could significantly enhance the circulating CD34(+) /VEGFR2(+) /CD45(-) EPCs levels in diabetic foot ulcer rats by 60% (P < 0.05) through the partial elevation of SDF-1α, restoring the mobilization ability of EPCs for wound neovascularization. We successfully isolated the BM-derived EPCs to study their angiogenic potential after NF3 treatment. BM-derived EPCs significantly expressed cell surface markers of CD34, CD146 and VEGFR2 (P < 0.05 - 0.01). NF3 could significantly stimulate the proliferation and attachment ability of EPCs dose-dependently (P < 0.01-0.001). Besides, NF3 could significantly augment EPCs migration (P < 0.001) and tube formation (P < 0.01-0.001). CONCLUSIONS: NF3 modulated diabetic wound healing through regulation of systemic EPCs level and increase in local vascular formation.

Novel PI3K/AKT targeting anti-angiogenic activities of 4-vinylphenol, a new therapeutic potential of a well-known styrene metabolite.

The pneumo- and hepato-toxicity of 4-vinylphenol (4VP), a styrene metabolite, has been previously reported. Nevertheless, the present study reported the novel anti-angiogenic activities of 4VP which was firstly isolated from the aqueous extract of a Chinese medicinal herb Hedyotis diffusa. Our results showed that 4VP at non-toxic dose effectively suppressed migration, tube formation, adhesion to extracellular matrix proteins, as well as protein and mRNA expressions of metalloproteinase-2 of human endothelial cells (HUVEC and HMEC-1). Investigation of the signal transduction revealed that 4VP down-regulated PI3K/AKT and p38 MAPK. Besides, 4VP interfered with the phosphorylation of ERK1/2, the translocation and expression of NFkappaB. In zebrafish embryo model, the new blood vessel growth was significantly blocked by 4VP (6.25-12.5 µg/mL medium). The VEGF-induced blood vessel formation in Matrigel plugs in C57BL/6 mice was suppressed by 4VP (20-100 µg/mL matrigel). In addition, the blood vessel number and tumor size were reduced by intraperitoneal 4VP (0.2-2 mg/kg) in 4T1 breast tumor-bearing BALB/c mice, with doxorubicin as positive control. Together, the in vitro and in vivo anti-angiogenic activities of 4VP were demonstrated for the first time. These findings suggest that 4VP has great potential to be further developed as an anti-angiogenic agent.

In vitro and in vivo mechanistic study of a novel proanthocyanidin, GC-(4→8)-GCG from cocoa tea (Camellia ptilophylla) in antiangiogenesis.

Angiogenesis, the process of blood vessel formation, is critical to tumor growth. Ant-angiogenic strategies demonstrated importance in cancer therapy. Cocoa tea (Camellia ptilophylla), a naturally decaffeinated tea commonly consumed as a healthy drink in southern China, had recently been found to be a potential candidate for antiangiogenesis. A novel proanthocyanidin, GC-(4→8)-GCG, which consisted of gallocatechin and gallocatechin 3-O gallate moieties, was discovered and thought to be one of the effective candidates for antiangiogenesis. Hence, the present study aimed to evaluate the antiangiogenesis activities of GC-(4→8)-GCG in vitro and in vivo, and SU5416 was applied as a positive control. The inhibitory effects of GC-(4→8)-GCG on three important processes involved in angiogenesis, i.e., proliferation, migration and differentiation, were examined using human microvascular endothelial cell line HMEC-1 by MTT assay, scratch assay and tube formation assay, respectively. Using transgenic zebrafish embryos TG(fli1:EGFP)y1/+(AB) as an animal model of angiogenesis, the antiangiogenic effect of GC-(4→8)-GCG was further verified in vivo. Our results demonstrated that GC-(4→8)-GCG significantly inhibited migration (P<.001) and tubule formation (P<.001-.05) of HMEC-1 in dose-dependent manner. Regarding intracellular signal transduction, GC-(4→8)-GCG attenuated the phosphorylation of ERK, Akt and p38 dose-dependently in HMEC-1. In zebrafish embryo, the formation of new blood vessels was effectively inhibited by GC-(4→8)-GCG in a dose-dependent manner after 3 days of treatment (P<.001-.05). In conclusion, these results revealed that our novel proanthocyanidin, GC-(4→8)-GCG might be a potential and promising agent of natural resource to be further developed as an antiangiogenic agent.

Antioxidant and antiangiogenic properties of phenolic extract from Pleurotus tuber-regium.

Pleurotus tuber-regium (Fries) Singer (PTR), both an edible and a medicinal mushroom also known as tiger milk mushroom, has experienced growing popularity and economic importance due to its flavor, nutritive value, and medicinal effects. In this study, the antioxidant and antiangiogenic activities of a 60% ethanol extract (EE) obtained from the sclerotium of PTR were investigated. Typical phenolic compounds including protocatechuic, chlorogenic, syringic, ferulic, and folic acid were identified and quantified in EE by the HPLC-UV-ESI/MS analyses. EE possessed strong antioxidant activity and could dose-dependently inhibit vascular endothelial growth factor (VEGF)-induced human umbilical vein endothelial cells (HUVEC) migration and tube formation. qPCR results showed that VEGF-induced FGF, ANG-Tie, and MMP gene expression as well as VEGFR were down-regulated at the mRNA level after treated with EE, suggesting that multiple molecular targets related to angiogenesis was involved. Furthermore, EE also inhibited the formation of subintestinal vessel plexus (SIVs) in zebrafish embryos in vivo. All of these suggested that EE of PTR could be the source of potential inhibitors to target angiogenesis.

Induction of Angiogenesis in Zebrafish Embryos and Proliferation of Endothelial Cells by an Active Fraction Isolated from the Root of Astragalus membranaceus using Bioassay-guided Fractionation.

The objective of the study was to identify the active fraction(s) from AR aqueous extract responsible for promoting angiogenesis using bioassay-guided fractionation. The angiogenic activity was screened by monitoring the increase of sprout number in sub-intestinal vessel (SIV) of the transgenic zebrafish embryos after they were treated with 0.06-0.25 mg/ml of AR aqueous extract or its fraction(s) for 96 h. Furthermore, the angiogenic effect was evaluated in treated zebrafish embryos by measuring the gene expression of angiogenic markers (VEGFA, KDR, and Flt-1) using real-time polymerase chain reaction (RT-PCR), and in human microvascular endothelial cell (HMEC-1) by measuring cell proliferation using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, (3)H-thymidine uptake assay, and cell cycle analysis. A major active fraction (P1-1-1), which was identified as glycoproteins, was found to significantly stimulate sprout formation (2.03 ± 0.27) at 0.125 mg/ml (P < 0.001) and up-regulate the gene expression of VEGFA, KDR, and Flt-1 by 2.6-fold to 8.2-fold. Additionally, 0.031-0.125 mg/ml of P1-1-1 was demonstrated to significantly stimulate cell proliferation by increasing cell viability (from 180% to 205%), (3)H-thymidine incorporation (from 126% to 133%) during DNA synthesis, and the shift of cell population to S phase of cell cycle. A major AR active fraction consisting of glycoproteins was identified, and shown to promote angiogenesis in zebrafish embryos and proliferation of endothelial cells in vitro.

Molecular mechanisms of angiogenesis effect of active sub-fraction from root of Rehmannia glutinosa by zebrafish sprout angiogenesis-guided fractionation.

ETHNOPHARMACOLOGICAL IMPORTANCE: The root of Rehmannia glutinosa (Rehmanniae Radix (RR)) is clinically used as a wound-healing agent in traditional Chinese medicine. Angiogenesis acts crucially in the pathogenesis of chronic wound healing. The present study investigated the angiogenesis effect and its underlying mechanism of RR through zebrafish sprout angiogenesis guided-fractionation. MATERIALS AND METHODS: The in vivo angiogenesis effect was studied by analyzing the number of ectopic sprouts formed upon sub-intestinal vessel of transgenic TG(fli1:EGFP)(y1)/+(AB) zebrafish embryos by fluorescence microscopy. Quantitative real-time PCR gene expression of the zebrafish embryos was further performed using a panel of 30 angiogenesis-associated genes designed for zebrafish sprout angiogenesis. Classical in vitro angiogenesis assays using human microvascular endothelial cells (HMEC-1) was accompanied. RESULTS: We demonstrated that among all RR sub-fractions tested, C1-1 treated-zebrafish embryos possessed the most potent angiogenesis activities (from 190 to 780 ng/ml, p<0.001) in sprout formation in the zebrafish model. Quantitative gene expression of the treated embryos demonstrated significant up-regulation in MMP-9 (p<0.05), ANGPT1 (p<0.05), EGFR (p<0.05), EPHB4 (p<0.01), and significant down-regulation in Ephrin B2 (p<0.05), Flt-1 (p<0.05) and Ets-1 (p<0.05). C1-1 treatment could also significantly (p<0.001-0.05) stimulate HMEC-1 cell migration in scratch assay. Significant increase (p<0.05) in mean tubule length was observed in the C1-1-treated HMEC-1 cells in the tubule formation assay. CONCLUSIONS: Our zebrafish sprout angiogenesis model-guided fractionation revealed that C1-1 possessed the most potent angiogenesis effect in RR. The design of the panel with 30 tailor-made angiogenesis-associated genes exhibited in zebrafish gene expression analysis showed that C1-1 could trigger differential expression of various angiogenesis-associated genes, such as VEGFR3 and MMP9, which played key role in angiogenesis. The pro-angiogenic activity of C1-1 was further confirmed in the translated study in motogenic and tubule-inducing effect using HMEC-1.