Bioactive C-phycocyanin exerts immunomodulatory and antitumor activity in mice with induced melanoma.

Melanoma is the most aggressive and deadly skin cancer. The difficulty in its treatment arises from its ability to suppress the immune system, making it crucial to find a substance that increases anti-tumor immunity. C-phycocyanin (C-PC) appears as a promising bioactive, with multifaceted effects against several cancers, but its efficacy against melanoma has only been tested in vitro. Therefore, we investigated C-PC's the anti-tumor and immunomodulatory action in a murine melanoma model. The tumor was subcutaneously induced in C57BL/6 mice by injecting B16F10 cells. The animals were injected subcutaneously with C-PC for three consecutive days. After euthanasia, the tumor was weighed and measured. The inguinal lymph node was removed, and the cells were stained with antibodies and analyzed by flow cytometry. The heart, brain and lung were analyzed by histopathology. C-PC increased the B cell population of the inguinal lymph node in percentage and absolute number. The absolute number of T lymphocytes and myeloid cells were also increased in the groups treated with C-PC. Thus, C-PC showed a positive immunomodulatory effect both animals with and without tumor. However, this effect was more pronounced in the presence of the tumor. Positive immune system modulation may be associated with a reduction in tumor growth in animals treated with C-PC. Administration of C-PC subcutaneously did not cause organ damage. Our findings demonstrate C-PC's immunomodulatory and anti-melanoma action, paving the way for clinical research with this bioactive.

Potential Therapeutic Targets of Quercetin in the Cutaneous Melanoma Model and Its Cellular Regulation Pathways: A Systematic Review.

Melanoma is a skin cancer with a high mortality rate due to its invasive characteristics. Currently, immunotherapy and targeted therapy increase patient survival but are ineffective in the advanced stages of the tumor. Quercetin (Que) is a natural compound that has demonstrated chemopreventive effects against different types of tumors. This review provides evidence for the therapeutic potential of Que in melanoma and identifies its main targets. The Scopus, Web of Science, and PubMed databases were searched, and studies that used free or encapsulated Que in melanoma models were included, excluding associations, analogs, and extracts. As a result, 73 articles were retrieved and their data extracted. Que has multiple cellular targets in melanoma models, and the main regulated pathways are cell death, redox metabolism, metastasis, and melanization. Que was also able to regulate important targets of signaling pathways, such as PKC, RIG-I, STAT, and P53. In murine models, treatment with Que reduced tumor growth and weight, and decreased metastatic nodules and angiogenic vasculature. Several studies have incorporated Que into carriers, demonstrating improved efficacy and delivery to tumors. Thus, Que is a promising therapeutic agent for the treatment of melanoma; however, further studies are needed to evaluate its effectiveness in clinical trials.

Morita-Baylis-Hillman adduct 2-(3-hydroxy-2-oxoindolin-3-yl)acrylonitrile (ISACN) modulates the inflammatory process during LPS-induced acute lung injury.

BACKGROUND: Despite its homeostatic role, inflammation is involved in several pathologies, such as acute lung injury. Morita-Ballys-Hilman adducts (MBHA) are a group of synthetic molecules and present a wide range of biological activities, including anti-inflammatory action. Thus, this study aimed to assess whether ISACN, an MBHA, modulates inflammation during acute lung injury induced by lipopolysaccharide (LPS). METHODS: BALB/c mice were intraperitoneally treated with 24 mg/kg ISACN and challenged with LPS (2.5 mg/kg). On bronchoalveolar lavage fluid (BALF), we assessed the total and differential leukocyte count and measurement of protein leakage, cytokines (IL-1ß, IL-6, and TNF-α), and chemokine (CXCL-1). Additionally, lung histopathology was also performed (H&E staining). In vitro studies were conducted with peritoneal macrophages to assess the possible mechanism of action. They were cultured in the presence of ISACN (5 and 10 µM) and stimulated by LPS (1 µg/mL). RESULTS: ISACN reduced neutrophil migration, protein leakage, and inflammatory cytokines (IL-1ß, IL-6, and TNF-α) without interfering with the production of CXCL1. In addition, ISACN caused a decrease in LPS-induced lung injury as evident from histopathological changes. In peritoneal macrophages, ISACN diminishes the nitric oxide and cytokine levels (IL-1ß, IL-6, and TNF-α). The treatment with ISACN (10 µM) also reduced LPS-induced TLR4, CD69, iNOS overexpression, and the LPS-induced ERK, JNK, and p38 phosphorylation. CONCLUSION: Thus, this work showed for the first time the immunomodulatory action of MBHA in LPS-induced acute lung injury and provided new evidence for the mechanisms related to the anti-inflammatory effect of ISACN.

C-phycocyanin decreases proliferation and migration of melanoma cells: In silico and in vitro evidences.

The incidence and number of deaths caused by melanoma have been increasing in recent years, and the pigment C-phycocyanin (C-PC) appears as a possible alternative to treat this disease. So, the objective of this study was to combine in silico and in vitro analysis to understand the main anti-melanoma pathways exerted by C-PC. We evaluated the ability of C-PC to bind to the main cellular targets related in the progression of melanoma through molecular docking, and the reflection of this bind in the biological effects in the B16F10 cell line through in vitro analysis. Our results showed that C-PC was able to bind BRAF and MEK, which are related to the signal transduction pathway for proliferation and survival. There was also an interaction between C-PC and cyclin-dependent kinase 4 and 6. In vitro analysis demonstrated that C-PC decreased B16F10 cell proliferation, as observed by cell viability and mitotic index assays. C-PC also interacted with matrix metalloproteinase 2 and 9 and N-cadherin, which may have caused the decrease in cell migration observed in vitro. Besides that, C-PC interacts with VEGF, a factor responsible for regulating the proliferation and cellular invasion pathways. Finally, C-PC did not alter the cell viability of the non-tumoral melanocytes. Therefore, C-PC is a strong anti-tumor candidate for the treatment of melanoma, since it acts in different cellular pathways of melanoma, without causing damage to non-tumoral cells.

Relation between ABCB1 overexpression and COX2 and ALOX5 genes in human erythroleukemia cell lines.

This study aimed to characterize the relationship between the COX2 and ALOX5 genes, as well as their link with the multidrug resistance (MDR) phenotype in sensitive (K562) and MDR (K562-Lucena and FEPS) erythroleukemia cells. For this, the inhibitors of 5-LOX (zileuton) and COX-2 (acetylsalicylic acid-ASA) and cells with the silenced ABCB1 gene were used. The treatment with ASA caused an increase in the gene expression of COX2 and ABCB1 in both MDR cell lines, and a decrease in the expression of ALOX5 in the FEPS cells. Silencing the ABCB1 gene induced a decrease in COX2 expression and an increase in the ALOX5 gene. Treatment with zileuton did not alter the expression of COX2 and ABCB1. Cytometry data showed that there was an increase in ABCB1 protein expression after exposure to ASA. In addition, the increased activity of ABCB1 in the K562-Lucena cell line indicates that ASA may be a substrate for this efflux pump, corroborating the molecular docking that showed that ASA can bind to ABCB1. Regardless of the genetic alteration in COX2 and ABCB1, the direct relationship between these genes and the inverse relationship with ALOX5 remained in the MDR cell lines. We assume that ABCB1 can play a regulatory role in COX2 and ALOX5 during the transformation of the parental cell line K562, explaining the increased gene expression of COX2 and decreased ALOX5 in the MDR cell lines.

Synthesis of pyrazoline fatty chain derivatives and its effects on melanoma cells.

Skin cancer is the most common type of cancer in Brazil, representing 30% of all cases. Among these, melanoma represents only 3% of malignant neoplasms; however, it is the most serious and has a high capacity for metastasis. For this reason, it is extremely important to identify more efficient compounds and treatments that stop or decrease the proliferation of melanoma, even in its more advanced stages. This work reports the synthesis and biological evaluation of two homologous series of pyrazoline fatty chain derivatives as potent antitumoral agents in the melanoma B16F10 cell line. Cells were treated with pyrazoline fatty chain compounds (3, 30, 300, and 3000 µM) for 0, 24, 48, and 72 h. Decreased cell viability was observed when using most compounds at different concentrations and times. The structure-activity relationship (SAR) between antitumoral activity and the number of carbons and lipophilicity, as well as the oxygen-sulfur bioisosteric exchange, was evaluated. Among the tested derivatives, the lipophilic compounds 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-carboxamide (2d) and 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-thiocarboxamide (3d) showed the best results in the B16F10 cell line, as they produced the best cell viability decrease effects. The presence of fatty unbranched undecyl chain in the molecular structure appears to be important for its antimelanoma properties.

Fatty-monastrol derivatives and its cytotoxic effect against melanoma cell growth.

Melanoma is the most dangerous type of skin cancer due to the occurrence of metastases. This work is aimed at studying the effects of the insertion of palmitic and oleic acid chain into monastrol in the melanoma cell line, B16F10. Cells were treated with monastrol, palmitic-monastrol or oleic-monastrol for periods of 0, 24, 48 and 72 h, and the cytotoxic effect was observed for palmitic-monastrol and oleic-monastrol after 24 h. For monastrol the effects were observed in 48 h on B16F10 cells, and in 24 h for a non-tumour cell line, melan-a. In this cell line, fatty-monastrol derivatives were cytotoxic after 24 h of exposure in the same concentrations as B16F10. However, oleic-monastrol inhibited cell growth at 20µM only after 72 h, in contrast to the B16F10 cell line, in which oleic-monastrol inhibited cell growth at 48 h, showing that at least in this structural modification, melan-a was less sensitive than B16F10. The ability of compounds to induce apoptosis and/or necrosis was measured, and it was observed that monastrol induces apoptosis within 24 h. However, the cells treated with fatty-monastrol derivatives did not remain adhered on the well plate after 3 h of treatment. At this time point, these cells still emitted fluorescence indicating viable cells, suggesting a possible effect of palmitic- and oleic-monastrol in the adhesion proteins found on the cell membrane.

Highly effective decontamination in a hospital environment: An easy-to-operate, low-cost prototype.

Healthcare-associated infections (HAI) are illnesses acquired during healthcare and are often the most important adverse event during healthcare. With the aim of increasing the effectiveness of disinfection/decontamination processes in the health service with safe and not promote microbial resistance, we propose the development of portable equipment associated with type C ultraviolet light (UVC). The efficiency of the irradiance emitted by the equipment (at dosages 3.5, 5.0, and 60 mJ/cm2) was determined by the action exerted after exposure against four different bacterial (Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) and three different fungi (Candida albicans, C. parapsilosis, and Aspergillus section Fumigati). It was possible to observe that all treatments were capable of inactivating the bacterial species evaluated (p < 0.05), causing the irreversible death of these microorganisms. The most effective elimination of fungal agents was at a dose of 60 mJ/cm2 of UVC radiation, with a decrease in the fungal inoculum varying between 94% and 100% in relation to the control without exposure. Thus, our study showed that the application of the portable prototype with UVC light (254 nm) at a distance of 48 mm, allowed an average irradiance of 3.5 mW/cm2, with doses of 3.5 ≈ 60 mJ/cm2 (from 1 to 60 s of exposure), which can promote the total reduction of the bacteria evaluated and significantly reduce fungal growth. Therefore, this prototype could be used safely and effectively in the hospital environment, considerably reducing contamination and contributing to the reduction of healthcare-associated infection risk.

Patulin inhibits LPS-induced nitric oxide production by suppressing MAPKs signaling pathway.

Patulin (PAT) is a natural product isolated from several species of fungi. Here, we evaluated the effect of PAT (62.5-4,000 ng/ml) in lipopolysaccharide (LPS)-activated murine peritoneal macrophages. Cell viability assay showed that PAT at concentrations up to 250 ng/ml did not affect macrophage viability. PAT (250 ng/ml) significantly reduced LPS-induced nitric oxide production (by 98.4%), inducible nitric oxide synthase (iNOS) expression (by 83.5%), and iNOS messenger ribonucleic acid expression (by 100.0%). Moreover, PAT significantly reduced LPS-induced interleukin-1ß (by 80.6%), cluster of differentiation (CD) 69 (by 63.1%), and Toll-like receptor (TLR) 4 (by 91.9%) protein expression. Finally, PAT significantly reduced LPS-triggered phosphorylation of all mitogen-activated protein kinases (MAPK) assessed: extracellular signal-regulated kinase (ERK; by 89.5%), c-Jun N-terminal kinase (JNK; by 77.5%), and p38 (by 72.3%). Taken together, these data suggest that PAT downregulates acute inflammatory response, inhibiting nitric oxide production by suppressing CD69-TLR4/ERK-JNK-p38 MAPKs/Nos2/iNOS signaling pathway.

C-Phycocyanin: Cellular targets, mechanisms of action and multi drug resistance in cancer.

C-Phycocyanin (C-PC) has been shown to be promising in cancer treatment; however, although several articles detailing this have been published, its main mechanisms of action and its cellular targets have not yet been defined, nor has a detailed exploration been conducted of its role in the resistance of cancer cells to chemotherapy, rendering clinical use impossible. From our extensive examination of the literature, we have determined as our main hypothesis that C-PC has no one specific target, but rather acts on the membrane, cytoplasm, and nucleus with diverse mechanisms of action. We highlight the cell targets with which C-PC interacts (the MDR1 gene, cytoskeleton proteins, and COX-2 enzyme) that make it capable of killing cells resistant to chemotherapy. We also propose future analyses of the interaction between C-PC and drug extrusion proteins, such as ABCB1 and ABCC1, using in silico and in vitro studies.

Interaction between omega 3 PUFA and UVB radiation: Photoprotective effect in normal and tumoral murine melanocytes?

Omega 3 polyunsaturated fatty acids (omega 3 PUFA) are attracting a growing interest as potential adjuvants for cancer prevention and treatment. There is evidence about photoprotection in normal cells, but few previous studies have evaluated it in tumoral cells. Therefore, this study investigated the effect of α-linolenic acid (ALA) in normal murine melanocytic cells (Melan-a) and in tumoral murine melanocytic cells (B16F10) exposed to UVB radiation. Our results showed that ALA exhibited an antiproliferative effect in B16F10 cells, and had minimal effect in Melan-a cells, as demonstrated by MTT assay. On the other hand, the combination of ALA (7.5µM) and UVB (0.01J/cm2) showed a protective effect for both cell lines, Melan-a and B16F10. ALA and UVB combined or UVB alone induced an accumulation of cell lines at the S/G2/M phase. In addition, the combination of ALA and UVB, and UVB alone, both induced cell death in 24h; and in 48h, ALA attenuated this effect in both cells. Further to these findings, it was demonstrated that ALA did not alter ROS levels in both cells exposed to UVB radiation. The effect of an omega 6 PUFA, linoleic acid, under the same conditions of ALA were tested. It was not protective in either cell line. Therefore, our results can be very important since it was shown another role to an omega 3 PUFA as a photoprotective agent in a melanoma cell.

Cardioprotective effect of eicosapentaenoic acid during ischemia and reperfusion / Efeito cardioprotetor do ácido eicosapentaenóico durante a isquemia e reperfusão

Objective: In this work, rats isolated hearts were infused EPA before the ischemia period and during reperfusion for available get well in parameter relatives to redox reactions. Methods: The effect of EPA was tested on isolated hearts induced to ischemia and reperfusion, treatment occurred at different times (ischemia or reperfusion). Antioxidant capacity against peroxyl radicals, glutathione cysteine ligase activity, glutathione concentration, lactate dehydrogenase, and creatine kinase concentration was analyzed. Results: Hearts treated with eicosapentaenoic acid had the minor generation of species reactive oxygen and lipid damage after reperfusion. The GSH concentration was higher when the hearts were treated with eicosapentaenoic acid in the period of reperfusion. Conclusion: In conclusion, this study demonstrates that the dose of EPA (20µM) used before ischemia can act as a cardioprotective antioxidant molecule, prevented damage heart from ischemic and reperfusion injury

Objetivo: Neste trabalho, corações isolados de ratos foram infundidos com EPA antes do período de isquemia e durante a reperfusão para obtenção de melhora em parâmetros relativos às reações redox. Métodos: O efeito do EPA foi testado em corações isolados induzidos a isquemia e reperfusão, o tratamento ocorreu em diferentes momentos (isquemia ou reperfusão). A capacidade antioxidante contra os radicais peroxil, atividade da glutationa cisteína ligase, concentração de glutationa, lactato desidrogenase e concentração de creatina quinase foi analisada. Resultados: Corações tratados com ácido eicosapentaenóico tiveram a menor geração de espécies reativas de oxigênio e danos lipídicos após a reperfusão. A concentração de GSH foi maior quando os corações foram tratados com ácido eicosapentaenóico no período de reperfusão. Conclusão: Em conclusão, este estudo demonstra que a dose de EPA (20µM) utilizada antes da isquemia pode atuar como uma molécula antioxidante cardioprotetora, prevenindo danos ao coração por isquemia e lesão de reperfusão.

Cell differentiation and the multiple drug resistance phenotype in human erythroleukemic cells.

The gene expression of Oct-4, a transcription factor and hematopoietic stem cell marker, is higher in Lucena lines, which is MDR, and the gene Alox-5 has also been implicated in the differentiation of some cell lines. The aim of this study was to compare the response to PMA-induced differentiation in MDR and non-MDR cells. We observed the differentiation to megakaryocytes in the K562 cell line, which is non-MDR. The expression of Alox-5 and Nanog genes was downregulated and that of Mdr-1 was upregulated in K562 cells. The Lucena cell line contained a higher number of megakaryocytes than the non-MDR, but this number was not altered by PMA, as well as Mdr-1 gene expression. However, Alox-5 expression was downregulated. Alox-5, Mdr-1, Nanog, Oct-4 and Sox-2 basal expression was also evaluated in the K562, Lucena and FEPS (also MDR) cell lines. The transcription factors gene expression was similar in MDR cell lines. The expression of Alox-5 was higher in the non-MDR cell line, while FEPS had the lowest expression of this gene. The opposite pattern was observed for Mdr-1 gene expression. These results suggest that the Alox-5 gene might play a role in the differentiation of these cell lines.

Anti-MDR and antitumoral action of acetylsalicylic acid on leukaemic cells.

ASA (acetylsalicylic acid) is an NSAID (non-steroidal anti-inflammatory drug). ASA has gained attention as a potential chemopreventive and chemotherapeutic agent for several neoplasms. The aim of this study was to analyse the possible antitumoural effects of ASA in two erythroleukaemic cell lines, with or without the MDR (multidrug resistance) phenotype. The mechanism of action of different concentrations of ASA were compared in K562 (non-MDR) and Lucena (MDR) cells by analysing cell viability, apoptosis and necrosis, intracellular ROS (reactive oxygen species) formation and bcl-2, p53 and cox-2 gene expression. ASA inhibited the cellular proliferation or induced toxicity in K562 and Lucena cell lines, irrespective of the MDR phenotype. The ASA treatment provoked death by apoptosis and necrosis in K562 cells and only by necrosis in Lucena cells. ASA also showed antioxidant activity in both cell lines. The bcl-2, p53 and cox-2 genes in both cell lines treated with ASA seem to exhibit different patterns of expression. However, normal lymphocytes treated with the same ASA concentrations were more resistant than tumoral cells. The results of this work show that both cell lines responded to treatment with ASA, demonstrating a possible antitumoral and anti-MDR role for this drug.

Nitric oxide-dependent pigment migration induced by ultraviolet radiation in retinal pigment cells of the crab Neohelice granulata.

The purpose of this study was to verify the occurrence of pigment dispersion in retinal pigment cells exposed to UVA and UVB radiation, and to investigate the possible participation of a nitric oxide (NO) pathway. Retinal pigment cells from Neohelice granulata were obtained by cellular dissociation. Cells were analyzed for 30 min in the dark (control) and then exposed to 1.1 and 3.3 J cm(-2) UVA, 0.07 and 0.9 J cm(-2) UVB, 20 nmß-PDH (pigment dispersing hormone) or 10 µm SIN-1 (NO donor). Histological analyses were performed to verify the UV effect in vivo. Cultured cells were exposed to 250 µm L-NAME (NO synthase blocker) and afterwards were treated with UVA, UVB or ß-PDH. The retinal cells in culture displayed significant pigment dispersion in response to UVA, UVB and ß-PDH. The same responses to UVA and UVB were observed in vivo. SIN-1 did not induce pigment dispersion in the cell cultures. L-NAME significantly decreased the pigment dispersion induced by UVA and UVB but not by ß-PDH. All retinal cells showed an immunopositive reaction against neuronal nitric oxide synthases. Therefore, UVA and UVB radiation are capable of inducing pigment dispersion in retinal pigment cells of Neohelice granulata and this dispersion may be nitric oxide synthase dependent.