RESUMO
Crotamine is a highly cationic polypeptide first isolated from South American rattlesnake venom, which exhibits affinity for acidic lysosomal vesicles and proliferating cells. This cationic nature is pivotal for its in vitro cytotoxicity and in vivo anticancer actions. This study aimed to enhance the antitumor efficacy of crotamine by associating it with the mesoporous SBA-15 silica, known for its controlled release of various chemical agents, including large proteins. This association aimed to mitigate the toxic effects while amplifying the pharmacological potency of several compounds. Comprehensive characterization, including transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential analysis, confirmed the successful association of crotamine with the non-toxic SBA-15 nanoparticles. The TEM imaging revealed nanoparticles with a nearly spherical shape and variations in uniformity upon crotamine association. Furthermore, DLS showed a narrow unimodal size distribution, emphasizing the formation of small aggregates. Zeta potential measurements indicated a distinct shift from negative to positive values upon crotamine association, underscoring its effective adsorption onto SBA-15. Intraperitoneal or oral administration of crotamine:SBA-15 in a murine melanoma model suggested the potential to reduce the frequency of crotamine doses without compromising efficacy. Interestingly, while the oral route enhanced the antitumor efficacy of crotamine, pH-dependent release from SBA-15 was observed. Thus, associating crotamine with SBA-15 could reduce the overall required dose to inhibit solid tumor growth, bolstering the prospect of crotamine as a potent anticancer agent.
RESUMO
Crotamine is a highly cationic polypeptide first isolated from South American rattlesnake venom, which exhibits affinity for acidic lysosomal vesicles and proliferating cells. This cationic nature is pivotal for its in vitro cytotoxicity and in vivo anticancer actions. This study aimed to enhance the antitumor efficacy of crotamine by associating it with the mesoporous SBA-15 silica, known for its controlled release of various chemical agents, including large proteins. This association aimed to mitigate the toxic effects while amplifying the pharmacological potency of several compounds. Comprehensive characterization, including transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential analysis, confirmed the successful association of crotamine with the non-toxic SBA-15 nanoparticles. The TEM imaging revealed nanoparticles with a nearly spherical shape and variations in uniformity upon crotamine association. Furthermore, DLS showed a narrow unimodal size distribution, emphasizing the formation of small aggregates. Zeta potential measurements indicated a distinct shift from negative to positive values upon crotamine association, underscoring its effective adsorption onto SBA-15. Intraperitoneal or oral administration of crotamine:SBA-15 in a murine melanoma model suggested the potential to reduce the frequency of crotamine doses without compromising efficacy. Interestingly, while the oral route enhanced the antitumor efficacy of crotamine, pH-dependent release from SBA-15 was observed. Thus, associating crotamine with SBA-15 could reduce the overall required dose to inhibit solid tumor growth, bolstering the prospect of crotamine as a potent anticancer agent.
RESUMO
Most of the deaths from skin cancer are caused by melanoma, a malignancy in which STAT3 plays a crucial role. The inhibition of STAT3 is considered a potential target to induce cell death, tumor regression and metastasis inhibition. The objective of this work was to evaluate the activity of the aqueous extract of Larrea divaricata (Aq), a fraction rich in polyphenols (EA),and the isolated compound quercetin-3-methyl ether (Q3ME) on B16F10 melanoma cells. The effects of Aq, EA and Q3ME were assessed on B16F10 cells by determining the proliferation, viability, apoptosis induction and the expression and phosphorylation of STAT3. The phytochemical composition of the extracts was determined by High Performance Liquid Chromatography. Aq, EA and Q3ME presented antiproliferative activity on B6F10 cells through p-STAT3 inhibition and early and late apoptosis induction (EC50 EA= ≤0.1 µg/ml; Aq= 316 ± 30 µg/ml; Q3ME= <0.1 µg/ml). L. divaricata could be considered for the development of adjuvant phytotherapies in melanoma treatment.
Assuntos
Larrea , Melanoma , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Larrea/química , Melanoma/tratamento farmacológico , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , ÁguaRESUMO
BACKGROUND: Photodynamic therapy (PDT) is a cancer treatment based on the interaction between the photosensitizing agent methylene blue (MB), light, and molecular oxygen. MB has antibacterial properties and can to bind to melanin. Here, we investigated whether MB based PDT (MB-PDT) could decrease viability and induce death of murine melanoma B16-F10 cells. METHODS: B16-F10 cells were incubated with different concentrations of MB (0, 1, or 2 µg/mL) and exposed to a diode red laser with a wavelength of 660 nm and power output of 100 mW/cm2. The energy dose and density varied from 0 J and 0 J/cm2 to 100.8 J and 720 J/cm². Cell viability was measured using the trypan blue exclusion assay of cell viability and confirmed by performing an MTT assay. The morphological type and cell death rates were determined using fluorescence microscopy with acridine orange and ethidium bromide. The presence and rate of apoptosis were evaluated via Annexin V-Alexa Fluor/propidium iodide staining and flow cytometry analysis. RESULTS: MB-PDT decreased cell viability and increased cell death (necrosis and apoptosis) in a drug- and light-dose dependent manner. Morphological characteristics of necrosis were observed immediately after treatment, and apoptotic characteristics were observed after 3 h. The apoptosis and necrosis rates varied with the drug and light doses, with 2 µg/mL MB and a 100.8 J energy dose inducing the highest rates. CONCLUSIONS: We demonstrated that MB-PDT reduced murine melanoma B16-F10 cell viability and induced cell death in a drug- and light-dose dependent manner.
Assuntos
Melanoma Experimental , Fotoquimioterapia , Animais , Apoptose , Morte Celular , Linhagem Celular Tumoral , Melanoma Experimental/tratamento farmacológico , Azul de Metileno/farmacologia , Camundongos , Necrose , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologiaRESUMO
Ouabain (OUA) is a glycoside shown to modulate B and T lymphocytes. Nevertheless, ouabain effects on B16F10 melanoma immune response, a mouse lineage that mimics human melanoma, are still unknown. Our aim was to study how OUA in vivo treatment modulates lymphocytes and if it improves the response against B16F10 cells. C57BL/6 mice were pre-treated with intraperitoneal (i.p) injection of OUA (0.56 mg/Kg) for three consecutive days. On the 4th day, 106 B16F10 cells or vehicle were i.p. injected. Animals were euthanized on days 4th and 21st for organs removal and subsequent lymphocyte analyses by flow cytometry. In vivo ouabain-treatment reduced regulatory T cells in the spleen in both melanoma and non-melanoma groups. Ouabain preserved the number and percentage of B lymphocytes in peripheral organs of melanoma-injected mice. Melanoma-injected mice pre-treated with OUA also survive longer. Our findings contribute to a better understanding of OUA immunological effects in a melanoma model.
Assuntos
Antineoplásicos/uso terapêutico , Linfócitos B/imunologia , Melanoma/tratamento farmacológico , Ouabaína/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Linfócitos T Reguladores/imunologia , Animais , Modelos Animais de Doenças , Feminino , Humanos , Imunomodulação , Injeções Intraperitoneais , Melanoma Experimental , Camundongos , Camundongos Endogâmicos C57BLRESUMO
An aqueous extract containing polysaccharides was obtained from the giant mushroom Macrocybe titans, and it was purified by amylase treatment, freeze-thawing process and dialysis. The purified fraction (ESP) was analyzed by HPSEC and GC-MS which showed a homogenous polysaccharide with Mw 14.2â¯×â¯103â¯g/mol composed by galactose and fucose. NMR and methylation analysis of ESP confirmed the presence of a fucogalactan with a (1â¯ââ¯6)-linked α-d-Galp main chain partially substituted at O-2 by non reducing end units of α-l-Fucp residues in the side chain. Its biological activity was evaluated against murine melanoma cells B16-F10. The fucogalactan did not alter the viability, proliferative capacity and morphology of cells. However, this polysaccharide was able to reduce the cell migration in vitro at 40% (100⯵g/mL) and 33% (250⯵g/mL). The results obtained showed that Macrocybe titans fucogalactan is a promising agent capable of altering melanoma cell migration without decrease the cell viability.
Assuntos
Agaricales/química , Movimento Celular/efeitos dos fármacos , Galactanos/farmacologia , Melanoma Experimental/patologia , Melanoma/patologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Galactanos/químicaRESUMO
A heteropolysaccharide was isolated by cold aqueous extraction from edible mushroom Pleurotus eryngii ("King Oyster") basidiocarps and its biological properties were evaluated. Structural assignments were carried out using mono- and bidimensional NMR spectroscopy, monosaccharide composition, and methylation analyses. A mannogalactan having a main chain of (1â6)-linked α-d-galactopyranosyl and 3-O-methyl-α-d-galactopyranosyl residues, both partially substituted at OH-2 by ß-d-Manp (MG-Pe) single-unit was found. Biological effects of mannogalactan from P. eryngii (MG-Pe) were tested against murine melanoma cells. MG-Pe was non-cytotoxic, but reduced in vitro melanoma cells invasion. Also, 50mg/kg MG-Pe administration to melanoma-bearing C57BL/6 mice up to 10days decreased in 60% the tumor volume compared to control. Additionally, no changes were observed when biochemical profile, complete blood cells count (CBC), organs, and body weight were analyzed. Mg-Pe was shown to be a promising anti-melanoma molecule capable of switching melanoma cells to a non-invasive phenotype with no toxicity to melanoma-bearing mice.
Assuntos
Polissacarídeos Fúngicos/farmacologia , Galactanos/farmacologia , Melanoma/tratamento farmacológico , Pleurotus/química , Animais , Carpóforos/química , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BLRESUMO
OBJECTIVE: Available chemotherapy presents poor control over the development of metastatic melanoma. FTY720 is a compound already approved by the Food and Drug Administration for the treatment of patients with multiple sclerosis. It has also been observed that FTY720 inhibits tumor growth in vivo (experimental models) and in vitro (animal and human tumor cells). The aim of this study was to evaluate the effects of FTY720 on a metastatic melanoma model and in tumor cell lines. METHODS: We analyzed FTY720 efficacy in vivo in a syngeneic murine metastatic melanoma model, in which we injected tumor cells intravenously into C57BL/6 mice and then treated the mice orally with the compound for 7 days. We also treated mice and human tumor cell lines with FTY720 in vitro, and cell viability and death pathways were analyzed. RESULTS: FTY720 treatment limited metastatic melanoma growth in vivo and promoted a dose-dependent decrease in the viability of murine and human tumor cells in vitro. Melanoma cells treated with FTY720 exhibited characteristics of programmed cell death, reactive oxygen species generation, and increased β-catenin expression. In addition, FTY720 treatment resulted in an immunomodulatory effect in vivo by decreasing the percentage of Foxp3+ cells, without interfering with CD8+ T cells or lymphocyte-producing interferon-gamma. CONCLUSION: Further studies are needed using FTY720 as a monotherapy or in combined therapy, as different types of cancer cells would require a variety of signaling pathways to be extinguished. .