Aqueous extract of Lithospermi radix attenuates oxaliplatin-induced neurotoxicity in both in vitro and in vivo models.

BACKGROUND: Oxaliplatin can induce peripheral neuropathy (OXIPN) as an adverse side effect in cancer patients. Until now, no effective preventive or therapeutic drug has been developed; therefore, the dose-limiting factor of OXIPN is still an obstacle in the use of oxaliplatin to treat cancer patients. In the present study, we report for the first time that the aqueous extract of Lithospermi radix (WLR) can attenuate the OXIPN in both in vitro and in vivo neuropathic models. METHODS: The protective effect of WLR on OXIPN was evaluated in vitro by quantifying nerve growth factor (NGF)-stimulated neurite outgrowth in PC12 cells treated with a combination of oxaliplatin and WLR. The neuroprotective potential of WLR was further confirmed by measuring the changes in nociceptive sensitivities to external mechanical stimuli in neuropathic animals induced by oxaliplatin. Histological and immunohistochemical studies were further done to examine the effect of WLR in mouse spinal cords and footpads. RESULTS: Oxaliplatin-induced neurotoxicity in NGF-stimulated PC12 cells. It could reduce the lengths and branching numbers of neuritis in NGF-stimulated PC12 cells. Co-treatment of WLR rescued the differentiated PC12 cells from the neurotoxicity of oxaliplatin. In a chronic OXIPN animal model, administration of oxaliplatin i.p. induced enhanced nociceptive sensitivity to mechanical stimuli (25.0 to 72.5 % of response rate) along with spinal activation of microglias and astrocytes and loss of intraepidermal nerve fibers in footpads, which is remarkably suppressed by oral administration of WLR (67.5 to 35 % of response rate at the end of experiment). Cytotoxicity of oxaliplatin determined in human cancer cells was not affected irrespective of the presence of WLR. CONCLUSIONS: In conclusion, we demonstrated that WLR can attenuate OXIPN in both in vitro and in vivo experimental models, which may be in part attributed to its anti-inflammatory activity in the spinal cord and its neuroprotective potential in the peripheral nerve system without affecting the anti-tumor potential of oxaliplatin. Therefore, WLR could be considered as a good starting material to develop a novel therapeutic agent targeting OXIPN. However, further studies should be done to elucidate the underlying mechanism such as molecular targets and active constituent(s) in WLR with neuroprotective potential.

Ethanolic extract of Descurainia sophia seeds sensitizes A549 human lung cancer cells to TRAIL cytotoxicity by upregulating death receptors.

BACKGROUND: Our previous genome-wide gene expression analysis revealed that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptors 4 (DR4) and 5 (DR5) are markedly upregulated by the ethanolic extract of D. sohia seeds (EEDS) in A549 TRAIL-refractory cancer cells. In the present study, we investigated whether the EEDS-mediated upregulation of TRAIL death receptors was associated with increased TRAIL-mediated toxicity in A549 cells in vitro. METHODS: Cell proliferation and viability were determined by an automatic cell counter. Gene silencing was performed by introducing small interfering RNA into cells. Expression changes of cellular proteins were determined by western blot analysis. Apoptotic cell death was monitored by western blot analysis. Analysis of variance followed by the post-hoc Dunnett's test was used to compare the data. RESULTS: EEDS treatment increased both mRNA and protein levels of DR4 and DR5 in the TRAIL refractory A549 cells. Co-treatment of A549 cells with sub-lethal dose of EEDS and recombinant TRAIL increased the apoptotic cell death. Upregulation of DR5 by EEDS was mediated by an endoplasmic reticulum stress-induced transcription factor, CCAAT/enhancer-binding protein homologous protein (CHOP), and knockdown of CHOP expression inhibited EEDS-induced DR5 upregulation and abolished the EEDS-associated increase in TRAIL toxicity in A549 cells. CONCLUSIONS: EEDS can sensitize A549 cells to TRAIL cytotoxicity by upregulation of TRAIL death receptors. Our findings suggested that EEDS is a good initial herbal source for the development of an anticancer supplement for anticancer therapeutics associated with TRAIL.

In Vivo Anti-tumor Effects of the Ethanol Extract of Gleditsia sinensis Thorns and Its Active Constituent, Cytochalasin H.

Angiogenesis is the process of new vessel formation from pre-existing blood vasculature and is critical for continuous tumor growth. We previously reported that an ethanolic extract of Gleditsia sinensis thorns (EEGS) and its active constituent, cytochalasin H, have anti-angiogenic activity in vitro and in vivo via suppression of endothelial cell functions. In the present study, EEGS and cytochalasin H were observed to efficiently inhibit tumor growth in an in ovo xenograft model without significant toxicity. We repeatedly observed the anti-tumor and anti-metastatic effects of EEGS in representative animal models. These results suggest that EEGS and its active constituent, cytochalasin H, are potential candidates for the development of anti-angiogenic cancer drugs.

5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone exerts its anticancer and antiangiogenesis effects through regulation of the Akt/mTOR signaling pathway in human lung cancer cells.

5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone (DHTMF) is one of the constituents of Vitex rotundifolia, a medicinal herb that is used for the treatment of various disorders in China and Korea. In this study we evaluated the antitumor and antiangiogeneic activities of DHTMF. DHTMF significantly suppressed growth and induced apoptosis in lung carcinoma cells in a dose-dependent manner, as indicated by a decrease in Bcl-2 levels and increases in Bax and cleaved caspase-3 levels. In addition, DHTMF treatment significantly reduced the phosphorylation of Akt and mammalian target of rapamycin (mTOR), accompanied by reductions in the protein level of hypoxia-inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF), which are key angiogenic molecules in H522 lung cancer cells. Furthermore DHTMF inhibited VEGF-induced angiogenesis, as indicated by reduced expression of CD34, tube formation and migration in human umbilical vein endothelial cells (HUVECs), as well as reduced neovascularization in an in vivo mouse Matrigel plug assay. DHTMF also inhibited phosphorylation of Akt, mTOR, and p70S6K in HUVECs and lung cancer cells. Taken together, our finding indicated that DHTMF inhibits Akt/mTOR signaling and reduces the expression of HIF-1 α and VEGF in tumor cells, which in turns inhibits endothelial cell-mediated angiogenesis. These results suggest that DHTMF inhibits angiogenesis as well as induces apoptosis via the Akt/mTOR pathway and might elicit pharmacological effects that are useful for treatment of lung cancer.

Ethanol extract of Kilkyung-baeksan, a traditional herbal formula, induces G0/G1 cell cycle arrest in human lung cancer cell lines.

BACKGROUND: Despite current advances in diagnostics and medicines, the incidence of lung cancer is increasing and effective treatment is very challenging. Traditional herbal formulae as well as many herbal plant extracts have been recognized as attractive sources for novel multi-targeted therapy of cancer with minimal side effects. METHODS: The ethanol extract of Kilkyung-baeksan (EE-KKBS) and its component herbs were tested for their ability to inhibit cancer growth in several lung cancer cell lines. The effects of EE-KKBS and ethanol extract of Croton tiglium Linné seed (EE-CT) on cell cycle progression were measured by flow cytometric analysis using propidium iodide staining. Western blot analyses were performed to measure the expression profiles of proteins regulating cell cycle checkpoints. RESULTS: EE-KKBS inhibited the growth of lung cancer cells after 24-72 hours treatment. Lung cancer cells treated with either EE-KKBS or EE-CT showed strong G0/G1 cell cycle arrest. The expressions of p21 and p27, two key regulators of G1 cell cycle checkpoint, were significantly upregulated upon treatment with EE-KKBS and EE-CT. CONCLUSION: EE-KKBS exerted its cytostatic activity through regulating G1 cell cycle checkpoint in lung cancer cells, and this activity is mainly mediated by one of its component herbs, seeds of Croton tiglium. Collectively, our data suggest that EE-KKBS could be a novel candidate for adjuvant therapy for lung cancer.

Anti-angiogenic potential of an ethanol extract of Annona atemoya seeds in vitro and in vivo.

BACKGROUND: Angiogenesis, which is initiated by certain tumor micro-environmental conditions and diverse protein factors, plays a pivotal role during tumor development and metastasis. Therefore, many efforts have been made to develop effective anti-angiogenic agents as anticancer therapeutics. In the current study, we investigated the anti-angiogenic potential of an ethanol extract of Annona atemoya seeds (EEAA) in vitro and in vivo. METHODS: The anti-angiogenic potential of EEAA was evaluated using various in vitro/in vivo models, including cell proliferation, migration, and tube formation by human umbilical vascular endothelial cells (HUVECs); a Matrigel plug assay; and tumor-induced angiogenesis. The expression of hypoxia-inducible factors (HIFs) and vascular endothelial growth factor (VEGF) was investigated using reverse transcription-polymerase chain reaction, immunoassays, and western blotting. RESULTS: EEAA was able to significantly inhibit the angiogenic properties of HUVECs in vitro as well as angiogenic factor-induced blood vessel formation in vivo. EEAA down-regulated the expression of VEGF and HIF-1alpha/2alpha at the mRNA and protein levels, respectively, in cancer cells under hypoxic conditions. CONCLUSIONS: EEAA shows a strong anti-angiogenic potential in both in vitro and in vivo systems, and we suggest that EEAA may be a valuable herbal source for anticancer drug development.

Cytochalasin H, an active anti-angiogenic constituent of the ethanol extract of Gleditsia sinensis thorns.

Angiogenesis, the process of new vessel formation from the pre-existing blood vasculature, is critical for continuous tumor growth and is considered to be a validated antitumor target. The results of our previous study demonstrate the anti-angiogenic potential of an extract of Gleditsia sinensis thorns, which has been traditionally used in Korean medicine to remedy diverse diseases, including tumors. In the present study, we attempted to identify the active anti-angiogenic constituents of the ethanol extract of G. sinensis thorns (EEGS). By virtue of in vitro activity-guided fractionation using human umbilical vein endothelial cells (HUVEC) primary endothelial cells, chromatographic separation, and NMR spectral analyses, we isolated and identified the potent active constituent, cytochalasin H, a biologically active secondary metabolite of fungi. This unexpected active constituent may have originated from the endophytic fungi, Chaetomium globosum, which naturally populate G. sinensis, the identity of which was determined by analysis of fungal community. Cytochalasin H isolated from the EEGS showed in vitro anti-angiogenic activities such as suppressed cell growth and mobility in HUVEC, and inhibited the pro-angiogenic protein-induced formation of new blood vessels in vivo. The anti-angiogenic effect of cytochalasin H was in part due to reduced expression of pro-angiogenic factor, such as endothelin-1. This is the first report regarding the isolation and identification of cytochalasin H, as an active anti-angiogenic constituent of G. sinensis thorns.

Screening of Stat3 inhibitory effects of Korean herbal medicines in the A549 human lung cancer cell line.

BACKGROUND: The transcription factor signal transducer and activator of transcription 3 (Stat3) is constitutively activated in many human cancers. It promotes tumor cell proliferation, inhibits apoptosis, induces angiogenesis and metastasis, and suppresses antitumor host immune responses. Therefore, Stat3 has emerged as a promising molecular target for cancer therapies. In this study, we evaluated the Stat3-suppressive activity of 38 herbal medicines traditionally used in Korea. METHODS: Medicinal herb extracts in 70% ethanol were screened for their ability to suppress Stat3 in the A549 human lung cancer cell line. A Stat3-responsive reporter assay system was used to detect intracellular Stat3 activity in extract-treated cells, and Western blot analyses were performed to measure the expression profiles of Stat3-regulated proteins. RESULTS: Fifty percent of the 38 extracts possessed at least mild Stat3-suppressive activities (i.e., activity less than 75% of the vehicle control). Ethanol extracts of Bupleurum falcatum L., Taraxacum officinale Weber, Solanum nigrum L., Ulmus macrocarpa Hance, Euonymus alatus Sieb., Artemisia capillaris Thunb., and Saururus chinensis (Lour.) Baill inhibited up to 75% of the vehicle control Stat3 activity level. A549 cells treated with these extracts also had reduced Bcl-xL, Survivin, c-Myc, and Mcl-1 expression. CONCLUSION: Many medicinal herbs traditionally used in Korea contain Stat3 activity-suppressing substances. Because of the therapeutic impact of Stat3 inhibition, these results could be useful when developing novel cancer therapeutics from medicinal herbs.

Magnolol suppresses vascular endothelial growth factor-induced angiogenesis by inhibiting Ras-dependent mitogen-activated protein kinase and phosphatidylinositol 3-kinase/Akt signaling pathways.

Magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, has been reported to possess anticancer activity. Recent studies have also demonstrated that magnolol inhibits cell growth and induces the apoptosis of cancer cells. However, the effects of magnolol on vascular endothelial growth factor (VEGF)-induced angiogenesis in endothelial cells have not been studied. In the present study, we have used human umbilical vein endothelial cells (HUVECs) to investigate the antiangiogenic effect and molecular mechanism of magnolol. Magnolol inhibited the VEGF-induced proliferation, chemotactic motility and tube formation of HUVECs in vitro as well as the vessel sprouting of the aorta ex vivo. Furthermore, magnolol inhibited VEGF-induced Ras activation and subsequently suppressed extracellular signal-regulated kinase (ERK), phosphatidylinositol-3-kinase (PI3K)/Akt and p38, but not Src and focal adhesion kinase (FAK). Interestingly, the knockdown of Ras by short interfering RNA produced inhibitory effects that were similar to the effects of magnolol on VEGF-induced angiogenic signaling events, such as ERK and Akt/eNOS activation, and resulted in the inhibition of proliferation, migration, and vessel sprouting in HUVECs. In combination, these results demonstrate that magnolol is an inhibitor of angiogenesis and suggest that this compound could be a potential candidate in the treatment of angiogenesis-related diseases.

Ethanol extract of Gleditsia sinensis thorn suppresses angiogenesis in vitro and in vivo.

BACKGROUND: Gleditsia sinensis thorns have been widely used in traditional Korean medicine for the treatment of several diseases, including obesity, thrombosis, and tumor-related diseases. The aim of the study is to determine the antiangiogenic effect of Gleditsia sinensis thorns in vitro and in vivo in a bid to evaluate its potential as an anticancer drug. METHODS: Ethanol extract of Gleditsia sinensis thorns (EEGS) were prepared and used for in vitro and in vivo assays. In vitro antiangiogenic effect of EEGS was determined in HUVEC primary cells by cell migration and tube formation assays. In vivo antiangiogenic effect of EEGS was determined by measuring vessel formation and vascular endothelial cells migrating into the implanted matrigels in nude mice. The angiogenesis-related proteins of which expression levels were altered by EEGS were identified by proteomic analysis. RESULTS: EEGS exerted a dose-dependent antiproliferative effect on HUVEC cells without significant cytotoxicity. Angiogenic properties, such as cell migration and tube formation, were significantly inhibited by EEGS in a dose-dependent manner. New vessel formation was also suppressed by EEGS, as determined by the directed in vivo angiogenesis assays in nude mice. EEGS reduced the expression of proangiogenic proteins, endothelin 1 and matrix metallopeptidase 2, in HUVEC cells. CONCLUSIONS: Our findings suggest that EEGS can inhibit angiogenesis by down-regulating proangiogenic proteins, and therefore it should be considered as a potential anticancer drug targeting tumor-derived angiogenesis.