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

Nutraceutical Features of the Phycobiliprotein C-Phycocyanin: Evidence from Arthrospira platensis (Spirulina)

Arthrospira platensis, commonly known as Spirulina, is a photosynthetic filamentous cyanobacterium (blue-green microalga) that has been utilized as a food source since ancient times. More recently, it has gained significant popularity as a dietary supplement due to its rich content of micro- and macro-nutrients. Of particular interest is a water soluble phycobiliprotein derived from Spirulina known as phycocyanin C (C-PC), which stands out as the most abundant protein in this cyanobacterium. C-PC is a fluorescent protein, with its chromophore represented by the tetrapyrrole molecule phycocyanobilin B (PCB-B). While C-PC is commonly employed in food for its coloring properties, it also serves as the molecular basis for numerous nutraceutical features associated with Spirulina. Indeed, the comprehensive C-PC, and to some extent, the isolated PCB-B, has been linked to various health-promoting effects. These benefits encompass conditions triggered by oxidative stress, inflammation, and other pathological conditions. The present review focuses on the bio-pharmacological properties of these molecules, positioning them as promising agents for potential new applications in the expanding nutraceutical market.

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.

Snake venom, a potential treatment for melanoma. A systematic review

Despite advances in treating patients with melanoma, there are still many treatment challenges to overcome. Studies with snake venom-derived proteins/peptides describe their binding potential, and inhibition of some proliferative mechanisms in melanoma. The combined use of these compounds with current therapies could be the strategic gap that will help us discover more effective treatments for melanoma. The present study aimed to carry out a systematic review identifying snake venom proteins and peptides described in the literature with antitumor, antimetastatic, or antiangiogenic effects on melanoma and determine the mechanisms of action that lead to these anti-tumor effects. Snake venoms contain proteins and peptides which are antiaggregant, antimetastatic, and antiangiogenic. The in vivo results are encouraging, considering the reduction of metastases and tumor size after treatment. In addition to these results, it was reported that these venom compounds could act in combination with chemotherapeutics (Acurhagin-C; Macrovipecetin), sensitizing and preparing tumor cells for treatment. There is a consensus that snake venom is a promising strategy for the improvement of antimelanoma therapies, but it has been little explored in the current context, combined with inhibitors, immunotherapy or tumor microenvironment, for example. We suggest Lebein as a candidate for combination therapy with BRAF inhibitors.

C-phycocyanin alleviated cisplatin-induced oxidative stress and inflammation via gut microbiota—metabolites axis in mice

C-phycocyanin is a natural protein extracted from Spirulina platensis. We aim to investigate the preventive effect of C-phycocyanin on cisplatin chemotherapy-induced oxidative damage and inflammation. The result showed that C-phycocyanin treatment reduced cisplatin-induced mortality and inflammation including decreased levels of serum IL6, kidney MCP1, and liver IL1β. Furthermore, C-phycocyanin also exerted antioxidant effects on mice, including increased GSH-Px, GGT, and GSH levels in the liver and increased CAT and SOD levels in the kidney. HepG2 cells experiments showed that C-phycocyanin exhibited none of the prevention effects on cisplatin injury. Faecalibaculum showed the greatest reduction among genera after cisplatin treatment, which was related to the enrichment of Romboutsia and Lactobacillus genera. C-phycocyanin treatment reduced the populations of harmful bacteria of Enterococcus faecalis, which was positively correlated with inflammation induced by cisplatin. C-phycocyanin increased the contents of 23-nordeoxycholic acid and β-muricholic acid. Moreover, C-phycocyanin increased amino acid-related metabolites, Nα-acetyl-arginine and trimethyl-lysine contents, and decreased fatty acid esters of hydroxy fatty acids (FAHFAs) contents. In conclusion, C-phycocyanin inhibited inflammation via the 23-nordeoxycholic acid-Enterococcus faecalis-inflammation axis, and enhanced the antioxidant capacity of kidney via Lactobacillus-NRF2 pathway. C-phycocyanin alleviated cisplatin injury via the modulation of gut microbiota, especially Lactobacillus and Enterococcus, as well as regulation of metabolites, especially bile acid and FAHFAs, which highlight the effect of C-phycocyanin and provide a new strategy to prevent cisplatin injury.