Bioguided isolation of a selective compound from Calea phyllolepis leaves against breast cancer cells.

Plants of the Calea genus have been reported to contain lipophilic compounds, such as sesquiterpene lactones, with cytotoxic effect against different cancer cell lines. The aim of this manuscript was to investigate the chemical profile and cytotoxic activity of different fractions from Calea phylolepis leaves on different human cancer cell lines. The fractions were prepared using solvent extraction of increasing polarity, yielding hexane, ethyl acetate and methanolic fractions. All fractions were chemically analysed by thin layer chromatography (TLC), and their cytotoxic activity against HT-29 (colon adenocarcinoma), MCF-7 (breast cancer), U-251MG (malignant glioblastoma) and L929 (mouse fibroblast) cell lines was investigated. Among these, the hexane and ethyl acetate fractions showed higher cytotoxic effects, while the methanolic fraction did not show any cytotoxic effects. The major bioactive compound from the hexane fraction (12.15%) was isolated using chromatographic methods and was identified by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS) analysis as 6-epi-ß-verbesinol coumarate. This compound showed activity against breast cancer cells (IC50 = 5.8 ± 1.0 µg/ml), similar to etoposide. Furthermore, 6-epi-ß-verbesinol coumarate showed low cytotoxicity to normal fibroblast cells, suggesting a high selectivity index (SI = 7.39) against breast cancer cells.

Prenylated 4-phenylcoumarins and 4-alkylcoumarins from Kielmeyera argentea and their cytotoxic activity.

Two new prenylated 4-phenylcoumarins, named kielcoumarin A (1) and kielcoumarin B (2) together with three known compounds, mammea B/BA (3), mammea B/BA cyclo F (4) and ferruol A (5), were obtained from stems and roots of Kielmeyera argentea (Calophyllaceae). Their structures were elucidated based on spectroscopic data. Cytotoxic activity of the 4-alkylcoumarins 3-5 was evaluated in vitro against human U251 glioblastoma cell line. Compound 3 showed significative activity with EC50 value of 6.6 µM while compounds 4 and 5 showed respective EC50 values of 52.0 and 37.0 µM.

A neglected natural source for targeting glioblastoma.

The cytotoxicity of the methanol extract of the freshwater sponge Ochridaspongia rotunda (Arndt, 1937) (Malawispongiidae) was evaluated by MTT assay at in vitro conditions against three brain tumour cell lines (Neuro-2A, U-251 MG and U-87 MG). The extract was actually found to be most effective against the malignant glioma U-251 MG cells reaching a promising IC50 value of 1.87 ± 0.09 µg/mL at 96 h. However, it exhibited only a bit of cytotoxicity (IC50 321.14 ± 11.29 µg/mL, 96 h) towards the normal cells. Also, this sponge extract was 5-fold more selective for U-251 MG versus U-87 MG cells. Finally, monitoring genotoxicity at chromosomal level using the micronucleus test practically revealed lack of any significant toxicity of O. rotunda extract, compared to doxorubicin.

Effect of 1α,25(OH)2 Vitamin D3 in Mutant P53 Glioblastoma Cells: Involvement of Neutral Sphingomyelinase1.

Glioblastoma is one the most aggressive primary brain tumors in adults, and, despite the fact that radiation and chemotherapy after surgical approaches have been the treatments increasing the survival rates, the prognosis of patients remains poor. Today, the attention is focused on highlighting complementary treatments that can be helpful in improving the classic therapeutic approaches. It is known that 1α,25(OH)2 vitamin D3, a molecule involved in bone metabolism, has many serendipidy effects in cells. It targets normal and cancer cells via genomic pathway by vitamin D3 receptor or via non-genomic pathways. To interrogate possible functions of 1α,25(OH)2 vitamin D3 in multiforme glioblastoma, we used three cell lines, wild-type p53 GL15 and mutant p53 U251 and LN18 cells. We demonstrated that 1α,25(OH)2 vitamin D3 acts via vitamin D receptor in GL15 cells and via neutral sphingomyelinase1, with an enrichment of ceramide pool, in U251 and LN18 cells. Changes in sphingomyelin/ceramide content were considered to be possibly responsible for the differentiating and antiproliferative effect of 1α,25(OH)2 vitamin D in U251 and LN18 cells, as shown, respectively, in vitro by immunofluorescence and in vivo by experiments of xenotransplantation in eggs. This is the first time 1α,25(OH)2 vitamin D3 is interrogated for the response of multiforme glioblastoma cells in dependence on the p53 mutation, and the results define neutral sphingomyelinase1 as a signaling effector.

Xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating endoplasmic reticulum stress-dependent CHOP pathway.

Xanthatin is a natural sesquiterpene lactone purified from Xanthium strumarium L., which has shown prominent antitumor activity against a variety of cancer cells. In the current study, we investigated the effect of xanthatin on the growth of glioma cells in vitro and in vivo, and elucidated the underlying mechanisms. In both rat glioma C6 and human glioma U251 cell lines, xanthatin (1-15 µM) dose-dependently inhibited cell viability without apparent effect on the cell cycle. Furthermore, xanthatin treatment dose-dependently induced glioma cell apoptosis. In nude mice bearing C6 glioma tumor xenografts, administration of xanthatin (10, 20, 40 mg·kg-1·d-1, ip, for 2 weeks) dose-dependently inhibited the tumor growth, but did not affect the body weight. More importantly, xanthatin treatment markedly increased the expression levels of the endoplasmic reticulum (ER) stress-related markers in both the glioma cell lines as well as in C6 xenografts, including glucose-regulated protein 78, C/EBP-homologous protein (CHOP), activating factor 4, activating transcription factor 6, spliced X-box binding protein-1, phosphorylated protein kinase R-like endoplasmic reticulum kinase, and phosphorylated eukaryotic initiation factor 2a. Pretreatment of C6 glioma cells with the ER stress inhibitor 4-phenylbutyric acid (4-PBA, 7 mM) or knockdown of CHOP using small interfering RNA significantly attenuated xanthatin-induced cell apoptosis and increase of proapoptotic caspase-3. These results demonstrate that xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating the ER stress-related unfolded protein response pathway involving CHOP induction. Xanthatin may serve as a promising agent in the treatment of human glioma.

Fe3O4@Au composite magnetic nanoparticles modified with cetuximab for targeted magneto-photothermal therapy of glioma cells.

BACKGROUND: Thermoresponsive nanoparticles have become an attractive candidate for designing combined multimodal therapy strategies because of the onset of hyperthermia and their advantages in synergistic cancer treatment. In this paper, novel cetuximab (C225)-encapsulated core-shell Fe3O4@Au magnetic nanoparticles (Fe3O4@Au-C225 composite-targeted MNPs) were created and applied as a therapeutic nanocarrier to conduct targeted magneto-photothermal therapy against glioma cells. METHODS: The core-shell Fe3O4@Au magnetic nanoparticles (MNPs) were prepared, and then C225 was further absorbed to synthesize Fe3O4@Au-C225 composite-targeted MNPs. Their morphology, mean particle size, zeta potential, optical property, magnetic property and thermal dynamic profiles were characterized. After that, the glioma-destructive effect of magnetic fluid hyperthermia (MFH) combined with near-infrared (NIR) hyperthermia mediated by Fe3O4@Au-C225 composite-targeted MNPs was evaluated through in vitro and in vivo experiments. RESULTS: The inhibitory and apoptotic rates of Fe3O4@Au-C225 composite-targeted MNPs-mediated combined hyperthermia (MFH+NIR) group were significantly higher than other groups in vitro and the marked upregulation of caspase-3, caspase-8, and caspase-9 expression indicated excellent antitumor effect by inducing intrinsic apoptosis. Furthermore, Fe3O4@Au-C225 composite-targeted MNPs-mediated combined hyperthermia (MFH+NIR) group exhibited significant tumor growth suppression compared with other groups in vivo. CONCLUSION: Our studies illustrated that Fe3O4@Au-C225 composite-targeted MNPs have great potential as a promising nanoplatform for human glioma therapy and could be of great value in medical use in the future.

Antioxidant and cytotoxic activities of Dendrobium moniliforme extracts and the detection of related compounds by GC-MS.

BACKGROUND: The medicinal orchid Dendrobium moniliforme contains water-soluble polysaccharides, phenanthrenes, bibenzyl derivatives, and polyphenol compounds. This study explored the antioxidant and cytotoxic activities of D. moniliforme extracts and detected their bioactive compounds. METHODS: Plant material was collected from the Daman of Makawanpur district in central Nepal. Plant extracts were prepared from stems using hexane, chloroform, acetone, ethanol and methanol. The total polyphenol content (TPC) in each extract was determined using Folin-Ciocalteu's reagent and the total flavonoid content (TFC) in each extract was determined using the aluminium chloride method. The in vitro antioxidant and cytotoxic activities of each extract were determined using DPPH (2,2-diphenyl-1-picrylhydrazyl) and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays respectively. Gas chromatography and mass spectrometry (GC-MS) analysis was used to detect bioactive compounds. RESULTS: TPC content was highest (116.65 µg GAE/mg of extract) in D. moniliforme chloroform extract (DMC) and TFC content was highest (116.67 µg QE/mg of extract) in D. moniliforme acetone extract (DMA). D. moniliforme hexane extract (DMH) extract showed the highest percentage of DPPH radical scavenging activity (94.48%), followed closely by D. moniliforme ethanol extract (DME) (94.45%), DMA (93.71%) and DMC (94.35%) at 800 µg/ml concentration. The antioxidant capacities of DMC, DMA, DMH and DME, which were measured in IC50 values, were much lower 42.39 µg/ml, 49.56 µg/ml, 52.68 µg/ml, and 58.77 µg/ml respectively than the IC50 of D. moniliforme methanol extract (DMM) (223.15 µg/ml). DMM at the concentration of 800 µg/ml most inhibited the growth of HeLa cells (78.68%) and DME at the same concentration most inhibited the growth of U251 cells (51.95%). The cytotoxic capacity (IC50) of DMM against HeLa cells was 155.80 µg/ml of extract and that of DME against the U251 cells was 772.50 µg/ml of extract. A number of bioactive compounds were detected in both DME and DMM. CONCLUSION: The fact that plant extract of D. moniliforme has a number of bioactive compounds which showed antioxidant and cytotoxic activities suggests the potential pharmacological importance of this plant.

Mixture Concentration-Response Modeling Reveals Antagonistic Effects of Estradiol and Genistein in Combination on Brain Aromatase Gene (cyp19a1b) in Zebrafish.

Comprehension of compound interactions in mixtures is of increasing interest to scientists, especially from a perspective of mixture risk assessment. However, most of conducted studies have been dedicated to the effects on gonads, while only few of them were. interested in the effects on the central nervous system which is a known target for estrogenic compounds. In the present study, the effects of estradiol (E2), a natural estrogen, and genistein (GEN), a phyto-estrogen, on the brain ER-regulated cyp19a1b gene in radial glial cells were investigated alone and in mixtures. For that, zebrafish-specific in vitro and in vivo bioassays were used. In U251-MG transactivation assays, E2 and GEN produced antagonistic effects at low mixture concentrations. In the cyp19a1b-GFP transgenic zebrafish, this antagonism was observed at all ratios and all concentrations of mixtures, confirming the in vitro effects. In the present study, we confirm (i) that our in vitro and in vivo biological models are valuable complementary tools to assess the estrogenic potency of chemicals both alone and in mixtures; (ii) the usefulness of the ray design approach combined with the concentration-addition modeling to highlight interactions between mixture components.

Antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of Psidium guineense Sw. and spathulenol.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves from Psidium guineense Sw. are used in popular medicine for the treatment of inflammatory disease. However, there is no scientific evidence demonstrating this activity. AIM OF THE STUDY: To evaluate the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of P. guineense and spathulenol (a major constituent). The study was conducted in part to provide evidence supporting the ethnobotanical use of the leaves of this species. MATERIAL AND METHODS: The essential oil (EOPG) was extracted from the leaves of P. guineense by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). The major compound, spathulenol (PG-1), was isolated in a chromatographic column and characterized by nuclear magnetic resonance (NMR). EOPG and PG-1 were evaluated in vitro for antioxidant activity by DPPH, ABTS and MDA methods; anti-inflammatory potential was assessed using two models, including pleurisy and oedema, in mice. The impact of EOPG and PG-1 on cell proliferation was determined via spectrophotometric quantification of the cellular protein content using a sulforhodamine B assay, and anti-Mycobacterium tuberculosis activity was determined using the REMA method. RESULTS: A total of 38 components were identified from the EOPG, with the sesquiterpenic alcohol spathulenol (PG-1) (80.7%) being the major constituent. EOPG and PG-1 exhibited the highest antioxidant activities in the DPPH and MDA system compared with reference standard, with IC50 values ranging from 26.13 to 85.60µg/mL. Oral administration of EOPG and PG-1 showed significant inhibition in the Cg-induced mice paw oedema and pleurisy model. The EOPG (GI50 = 0.89µg/mL) and PG-1 (GI50 = 49.30µg/mL) were particularly effective against the ovarian cancer cell line. Both showed moderate antimycobacterial activity. CONCLUSION: For the first time, this study demonstrated the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial properties of the essential oil of P. guineense (leaves were collected in Dourados-MS) and spathulenol, collaborating the etnhopharmacologycal use of this plant due to its an anti-inflammatory effect.

Proteomic analysis of ß-asarone induced cytotoxicity in human glioblastoma U251 cells.

Though rhizoma acori graminei (RAG) is frequently prescribed in formulations for brain tumor in traditional Chinese medicine, the potential mechanisms are still unclear. The aim of this study is to determine the effect of ß-asarone, a major component in the volatile oil of RAG, against brain tumor and elucidate the underlying molecular mechanisms. The results showed that ß-asarone significantly inhibited the cell viability of human glioblastoma U251 cells. Moreover, YO-PRO-1/PI staining revealed that cells treated with ß-asarone underwent apoptotic and necrotic death. Then, the two-dimensional gel electrophoresis (2-DE)-based proteomics was applied to investigate the different protein profiles of U251 cells treated with vehicle or ß-asarone. Sixteen proteins affected by ß-asarone were successfully identified by MALDI-TOF/TOF mass spectrometry. Gene ontology analysis showed that those proteins participated in several important biological processes and exhibited diverse molecular functions. Importantly, four proteins (heterogeneous nuclear ribonucleoprotein H1 (H), isoform CRA_b, heterogeneous nuclear ribonucleoprotein A2/B1, isoform CRA_a, ubiquitin carboxyl-terminal hydrolase isozyme L1 and cathepsin D) acting as either oncoproteins or tumor suppressors draw our special attention. Finally, the effect of ß-asarone on these four genes was confirmed at transcriptional level by semi-quantitative RT-PCR. Collectively, a variety of proteins affected by ß-asarone were identified by 2-DE coupled with MALDI-TOF/TOF MS/MS analysis. Four potential protein targets were proposed, which will enable a better understanding of the anti-tumor activity of ß-asarone.

Antiproliferative effects of Tubi-bee propolis in glioblastoma cell lines.

Propolis is a resin formed by a complex chemical composition of substances that bees collect from plants. Since ancient times, propolis has been used in folk medicine, due to its biological properties, that include antimicrobial, anti-inflammatory, antitumoral and immunomodulatory activities. Glioblastoma is the most common human brain tumor. Despite the improvements in GBM standard treatment, patients' prognosis is still very poor. The aim of this work was to evaluate in vitro the Tubi-bee propolis effects on human glioblastoma (U251 and U343) and fibroblast (MRC-5) cell lines. Proliferation, clonogenic capacity and apoptosis were analyzed after treatment with 1 mg/mL and 2 mg/mL propolis concentrations for different time periods. Additionally, glioblastoma cell lines were submitted to treatment with propolis combined with temozolomide (TMZ). Data showed an antiproliferative effect of tubi-bee propolis against glioblastoma and fibroblast cell lines. Combination of propolis with TMZ had a synergic anti-proliferative effect. Moreover, propolis caused decrease in colony formation in glioblastoma cell lines. Propolis treatment had no effects on apoptosis, demonstrating a cytostatic action. Further investigations are needed to elucidate the molecular mechanism of the antitumor effect of propolis, and the study of its individual components may reveal specific molecules with antiproliferative capacity.

Antiproliferative effects of Tubi-bee propolis in glioblastoma cell lines

Propolis is a resin formed by a complex chemical composition of substances that bees collect from plants. Since ancient times, propolis has been used in folk medicine, due to its biological properties, that include antimicrobial, anti-inflammatory, antitumoral and immunomodulatory activities. Glioblastoma is the most common human brain tumor. Despite the improvements in GBM standard treatment, patients' prognosis is still very poor. The aim of this work was to evaluate in vitro the Tubi-bee propolis effects on human glioblastoma (U251 and U343) and fibroblast (MRC-5) cell lines. Proliferation, clonogenic capacity and apoptosis were analyzed after treatment with 1 mg/mL and 2 mg/mL propolis concentrations for different time periods. Additionally, glioblastoma cell lines were submitted to treatment with propolis combined with temozolomide (TMZ). Data showed an antiproliferative effect of tubi-bee propolis against glioblastoma and fibroblast cell lines. Combination of propolis with TMZ had a synergic antiproliferative effect. Moreover, propolis caused decrease in colony formation in glioblastoma cell lines. Propolis treatment had no effects on apoptosis, demonstrating a cytostatic action. Further investigations are needed to elucidate the molecular mechanism of the antitumor effect of propolis, and the study of its individual components may reveal specific molecules with antiproliferative capacity.