C-Phycocyanin from Oscillatoria tenuis exhibited an antioxidant and in vitro antiproliferative activity through induction of apoptosis and G0/G1 cell cycle arrest

C-phycocyanin acts as a positive immunomodulator in different primary and secondary organs of mice

OBJECTIVE

C-Phycocyanin (C-PC) is a photosynthetic pigment with interesting therapeutic properties. However, its effectiveness in modulating the immune system cell populations has not been elucidated. We analyzed the action of C-PC on the modulation of mice immune system.

METHODS

The animals were treated subcutaneously with C-PC for 3 consecutive days. On the fourth day, the animals were euthanized and cells from different organs were analyzed by flow cytometry. Cytotoxicity was analyzed using biochemical parameters.

RESULTS

The results showed that C-PC increased the total cellularity in percentage and absolute number in the inguinal lymph node as well as the absolute number of B cells, CD4+ and CD8+ T cells and myeloid cells. The percentage of B cells was also increased in the lymph node. In the bone marrow, there was a reduction in immature and mature B cells. In contrast, C-PC increased the percentage and absolute number of myeloid cells in the bone marrow. C-PC administration also promoted an increase of CD4+ and CD8+ T cells in the thymus, and a reduction in these populations in the spleen.

CONCLUSION

The data show for the first time the positive immunomodulatory role of C-PC by recruiting distinct populations of immune system cells to the treatment-draining lymphoid organ.

Phormidium versicolor PC skin cream evaluation for its stability and biological activities

In the present investigation, 13% ± 0.84 of the extracted and purified phycocyanin from Phormidium versicolor was obtained, with a purity of 0.69 following dialysis. FT-IR analysis of purified phycocyanin revealed stretching vibration peaks in the profiles of the functional groups of N-H, O-H, C = O, N-H, C = O, and C = NH+. The phycocyanin had a significant DPPH radical scavenging ability (IC50 = 0.6 ± 0.02 mg mL-1) confirmed with FRAP assay, and it exhibited microbiological activity between 1.25 and 2.5 mg mL-1 against Candida albicans, Klebsiella pneumoniae, and Enterococcus faecalis. Phycocyanin showed no cytotoxic and improved the viability of HEK-293. It was added to skin cream at a rate of 6 mg g-1 because of its significant yield extraction and biological activity. At 10 mg mL-1, a bactericidal activity has been noted, inhibiting the growth of bacteria responsible for inflammatory skin conditions. For 60 days, the emulsion's stability was monitored at room temperature, 25 °C, and 45 °C. The appearance of the batch kept at 45 °C was changed to beige after 7 days, while the others were kept for 15 days. Skin creams enhanced with phycocyanin were found to be stable over the course of storage at both room temperature and 25 °C, based on centrifugation stability analysis. But starting on the fifteenth day, the items kept at 45 °C were unstable. Thus, the current study's findings are in favor of using phycocyanin as an antioxidant in cosmetic products. However, further investigation is required before using it in clinical trials. KEY POINTS: • Phycocyanin extraction field (13%) is particularly significant compared to other cyanobacteria. • Phycocyanin at 0.6 μg g-1 in skin cream fights bacteria in skin inflammation. • Phycocyanin-enriched cream was stable at room temp, 25 °C, and unstable at 45 °C after day 15.

Antibacterial and antibiofilm activity of silver nanoparticles stabilized with C-phycocyanin against drug-resistant Pseudomonas aeruginosa and Staphylococcus aureus

Background

Biofilms are bacterial communities that can protect them against external factors, including antibiotics. In this study, silver nanoparticles (AgNPs) were formed by modifying AgNPs with C-phycocyanin (Ag-Pc) to inhibit the growth of carbapenem-resistant Pseudomonas aeruginosa (CR P. aeruginosa) and methicillin-resistant Staphylococcus aureus (MRSA) and destroy biofilm of these bacteria.

Methods

The AgNPs were prepared with the green synthesis method, and Pc was used to stabilize the AgNPs. The Ag-Pc's antibacterial and antibiofilm effects were evaluated using the Microbroth dilution method and microtiter plate assay. The inhibitory effect of Ag-Pc on the expression of biofilm-related genes was evaluated by real-time PCR. Moreover, the MTT assay was used to assess the Ag-Pc toxicity.

Results

The Ag-Pc minimum inhibitory concentration (MIC) was 7.4 μg/mL for CR P. aeruginosa and MRSA. Pc did not show antibacterial effects against any of the strains. Ag-Pc suppressed biofilm formation and destroyed matured biofilm in both bacteria more efficiently than the AgNPs (P< 0.05). The expression of all genes was not significantly reduced in the presence of synthesized nanoparticles. Finally, the MTT assay results did not show toxicity against a murine fibroblast cell line (L929) at MIC concentration.

Conclusion

The present study showed the promising potential of Pc for improving the antibacterial and antibiofilm function of AgNPs and inhibiting drug-resistant bacteria. Therefore, Ag-Pc nanoparticles can be considered a promising therapeutic approach for the managing of the bacterial biofilm.

Combining In Vitro, In Vivo, and Network Pharmacology Assays to Identify Targets and Molecular Mechanisms of Spirulina-Derived Biomolecules against Breast Cancer

The current research employed an animal model of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary gland carcinogenesis. The estrogen receptor-positive human breast adenocarcinoma cell line (MCF-7) was used for in vitro analysis. This was combined with a network pharmacology-based approach to assess the anticancer properties of Spirulina (SP) extract and understand its molecular mechanisms. The results showed that the administration of 1 g/kg of SP increased the antioxidant activity by raising levels of catalase (CAT) and superoxide dismutase (SOD), while decreasing the levels of malonaldehyde (MDA) and protein carbonyl. A histological examination revealed reduced tumor occurrence, decreased estrogen receptor expression, suppressed cell proliferation, and promoted apoptosis in SP protected animals. In addition, SP disrupted the G2/M phase of the MCF-7 cell cycle, inducing apoptosis and reactive oxygen species (ROS) accumulation. It also enhanced intrinsic apoptosis in MCF-7 cells by upregulating cytochrome c, Bax, caspase-8, caspase-9, and caspase-7 proteins, while downregulating Bcl-2 production. The main compounds identified in the LC-MS/MS study of SP were 7-hydroxycoumarin derivatives of cinnamic acid, hinokinin, valeric acid, and α-linolenic acid. These substances specifically targeted three important proteins: ERK1/2 MAPK, PI3K-protein kinase B (AKT), and the epidermal growth factor receptor (EGFR). Network analysis and molecular docking indicated a significant binding affinity between SP and these proteins. This was verified by Western blot analysis that revealed decreased protein levels of p-EGFR, p-ERK1/2, and p-AKT following SP administration. SP was finally reported to suppress MCF-7 cell growth and induce apoptosis by modulating the PI3K/AKT/EGFR and MAPK signaling pathways suggesting EGFR as a potential target of SP in breast cancer (BC) treatment.

Characterization of C-phycocyanin antioxidant, anti-inflammatory, anti-tumour, and anti-HCoV-229E activities and encapsulation for implementation in an innovative functional yogurt

Functional bioactive ingredients isolated from microalgae as sustainable sources have become a new subject of pharmacology and functional foods. Thus, the work aims to produce crude phycocyanin (C-PC), define it, and investigate its pharmacological effects before warping it in a nanophytosome. Subsequently, the physicochemical properties of nanoparticles were evaluated. Both free and nanophytosomes of C-PC were incorporated into cow milk fermented with the probiotic Lactobacillus rhamnosus KU985435 to make functional yoghurt and the stability of C-PC of both phytosomes was assessed. The amino acid content of C-PC revealed the presence of eight of nine essential amino acids and eight of eleven non-essential amino acids. C-PC has a medium molecular weight (82.992 kDa). Some pharmacological effects like reducing inflammation (98.76 % ± 0.065), fighting free radicals (99.12 % ± 0.027), and being able to inhibit the human coronavirus 229 E with a selective index of 27.9 were observed. The maximum viral inhibitory activity was detected during the adsorption stage. Anti-human liver and colon carcinomas that exceeded Doxorubicin with very low cytotoxicity against normal cell lines were detected. C-PC is an unstable protein that could be degraded in the yoghurt during storage. Therefore, phytosome encapsulation can effectively stabilize C-PC (particle size 44.50 ± 12 nm and zeta-potential -32.4 ± 5 mV) and protect it from the acidic environment of the yoghurt. The produced yoghurt showed the desired physicochemical and functional properties and overall acceptance. The results prove that C-PC from spirulina algae is a renewable source of dyes. The encapsulation process using phytosomes gave it high stability against environmental influences, and therefore, it can be applied in the food and pharmaceutical industries in the future.

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.

Response of Arthrospira platensis to nitrogen depletion and the effect of aqueous extracts on tumor and non-tumor cells

The microalgae Arthrospira platensis (AP), commonly known as Spirulina, has gained widespread popularity as a food supplement in recent years. AP is particularly abundant in protein, B vitamins, iron, magnesium, potassium, and various antioxidants. In this study we aimed to evaluate the effect of nitrate limitation in the AP culture medium on AP growth and composition. In addition, the cytotoxicity of the respective aqueous AP extracts on three different mammalian cell-lines (HepG2, Caco2, L929) was tested. AP was cultivated over a 10-day period under nitrogen-rich (Nrich: 1.8 g/L) and nitrogen-deficient (Nlimited: 0.2-0.4 g/L) conditions in two separate experiments, each with three biological replicates (three bioreactors). Throughout the cultivation, the kinetic progress of dry biomass, pH, pigment content, the levels of essential elements (sulphur, phosphate, and nitrate) and the composition of elements in the harvested biomass was determined. While the biomass slightly but significantly differed, the phycocyanin concentration differed considerably (around 10-fold higher in the Nrich medium, p < 0.05). Aqueous extracts of the Nrich medium had significantly stronger effects on the cell membrane integrity and the metabolic activity of the cells than extracts of the Nlimited medium. Particularly was the finding that AP had a significantly stronger toxic effect on the two tumour cell types (HepG2, Caco2) than on the non-tumour cells (L929). This study underscores the significance of nitrate content in the cultivation media of AP.

Properties and potential applications of bioconjugates of R-phycoerythrin with Ag° or CdS nanoparticle synthesized in its tunnel cavity: A review

Green synthesis is a promising method for the preparation of nanoparticles (NPs) due to its simplicity, low cost, low toxicity, and environmental friendliness. Biosynthesized NPs exhibit multifunctional activity, good biocompatibility, and higher anticancer and antibacterial activity compared to chemically synthesized NPs. R-phycoerythrin, a photosynthetic light-harvesting pigment of protein nature (M.w. 290 kDa), is an attractive platform for the synthesis of small sizes NPs due to its structural features, non-toxicity, water solubility. Photosensitive bioconjugates of R-phycoerythrin with NPs were prepared by synthesizing Ag° and CdS NPs in tunnel cavities of R-phycoerythrin (3.5 × 6.0 nm) isolated from the red seaweed Callithamnion rubosum. The review is devoted to the physical processes and chemical reactions that occur in the native protein macromolecule of a complex structure during the synthesis of a NP in its cavity. The influence of Ago and CdS NPs on the electronic processes caused by the absorption of photons, leading to reversible and irreversible changes in R-phycoerythrin has been analyzed. Properties of R-phycoerythrin bioconjugates Ag° and CdS with NPs combined with the literature data suggest potential applications of Ag°⋅PE and CdS⋅PE bioconjugates for cancer diagnosis, treatment, and monitoring as well as for realizing theranostic strategy in the future. The use of these bioconjugates in anticancer therapy may have synergistic effects since both R-phycoerythrin and NPs induce cancer cell death.

Exploring the Benefits of Phycocyanin: From Spirulina Cultivation to Its Widespread Applications

Large-scale production of microalgae and their bioactive compounds has steadily increased in response to global demand for natural compounds. Spirulina, in particular, has been used due to its high nutritional value, especially its high protein content. Promising biological functions have been associated with Spirulina extracts, mainly related to its high value added blue pigment, phycocyanin. Phycocyanin is used in several industries such as food, cosmetics, and pharmaceuticals, which increases its market value. Due to the worldwide interest and the need to replace synthetic compounds with natural ones, efforts have been made to optimize large-scale production processes and maintain phycocyanin stability, which is a highly unstable protein. The aim of this review is to update the scientific knowledge on phycocyanin applications and to describe the reported production, extraction, and purification methods, including the main physical and chemical parameters that may affect the purity, recovery, and stability of phycocyanin. By implementing different techniques such as complete cell disruption, extraction at temperatures below 45 °C and a pH of 5.5-6.0, purification through ammonium sulfate, and filtration and chromatography, both the purity and stability of phycocyanin have been significantly improved. Moreover, the use of saccharides, crosslinkers, or natural polymers as preservatives has contributed to the increased market value of phycocyanin.

Therapeutical and Nutraceutical Roles of Cyanobacterial Tetrapyrrole Chromophore: Recent Advances and Future Implications

Cyanobacteria have attracted the attention of researchers because of their promising role as primary and secondary metabolites in functional food and drug design. Due to an ever-increasing awareness of health and the use of natural products to avoid the onset of many chronic and lifestyle metabolic diseases, the global demand for the use of natural drugs and food additives has increased in the last few decades. There are several reports about the highly valuable cyanobacterial products such as carotenoids, vitamins, minerals, polysaccharides, and phycobiliproteins showing antioxidant, anti-cancerous, anti-inflammatory, hypoglycemic, and antimicrobial properties. Recently, it has been shown that allophycocyanin increases longevity and reduces the paralysis effect at least in Caenorhabditis elegans. Additionally, other pigments such as phycoerythrin and phycocyanin show antioxidative properties. Because of their high solubility in water and zero side effects, some of the cyanobacterial tetrapyrrole derivatives, i.e., pigments, facilitate an innovative and alternative way for the beverage and food industries in place of synthetic coloring agents at the commercial level. Thus, not only are the tetrapyrrole derivatives essential constituents for the synthesis of most of the basic physiological biomolecules, such as hemoglobin, chlorophyll, and cobalamin, but also have the potential to be used for the synthesis of synthetic compounds used in the pharmaceutical and nutraceutical industries. In the present review, we focused on the different aspects of tetrapyrrole rings in the drug design and food industries and addressed its remaining limitations to be used as natural nutrient supplements and therapeutic agents.

Antioxidant Efficacy of a Spirulina Liquid Extract on Oxidative Stress Status and Metabolic Disturbances in Subjects with Metabolic Syndrome

Lipid peroxidation is associated with the development of some pathologies, such as cardiovascular diseases. Reduction in oxidative stress by antioxidants, such as Arthrospira (formely Spirulina), helps improving this redox imbalance. The aim of the study was to evaluate the effect of the Arthrospira liquid extract “Spirulysat^®” on oxidative markers—in particular, oxidized LDL (oxLDL)/total LDL cholesterol—and isoprostanes and to investigate its impact on lipid and glucose metabolism in the metabolic syndrome subject. A controlled, randomised, double-blind design was conducted in 40 subjects aged 18 to 65 years with metabolic syndrome after a daily intake of Spirulysat^® or placebo for twelve weeks. Blood and urinary samples were collected at three visits (V1, V2, V3) in the two groups for parameters determination. Although the Spirulysat^® group showed a decrease at all visits of the oxLDL/total cholesterol ratio, there was no significant difference compared to the placebo (p = 0.36). The urinary isoprostanes concentration in the Spirulysat^® group was reduced (p = 0.014) at V3. Plasma triglycerides decreased at V3 (p = 0.003) and HDL-cholesterol increased (p = 0.031) at all visits with Spirulysat^®. In conclusion, Spirulysat^® did not change the oxidized LDL (oxLDL)/LDL ratio but decreased the urinary isoprostanes, plasma triglycerides and increased HDL cholesterol, suggesting a beneficial effect on metabolic syndrome.

The Bioactivities of Phycocyanobilin from Spirulina

Phycocyanobilin (PCB) is a linear open-chain tetrapyrrole chromophore that captures and senses light and a variety of biological activities, such as anti-oxidation, anti-cancer, and anti-inflammatory. In this paper, the biological activities of PCB are reviewed, and the related mechanism of PCB and its latest application in disease treatment are introduced. PCB can resist oxidation by scavenging free radicals, inhibiting the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and delaying the activity of antioxidant enzymes. In addition, PCB can also be used as an excellent anti-inflammatory agent to reduce the proinflammatory factors IL-6 and IFN-γ and to up-regulate the production of anti-inflammatory cytokine IL-10 by inhibiting the inflammatory signal pathways NF-κB and mitogen-activated protein kinase (MAPK). Due to the above biological activities of phycocyanobilin PCB, it is expected to become a new effective drug for treating various diseases, such as COVID-19 complications, atherosclerosis, multiple sclerosis (MS), and ischaemic stroke (IS).

Comparison of the antibacterial properties of phycocyanin and its SNPs and their effects on rat blood cells and liver enzymes

Background

Phycocyanin is an important protein in cyanobacteria that has many medical and therapeutic properties. The aim of the present study was to compare the antibacterial properties of phycocyanin and its SNPs and to evaluate their effects on rat blood cells and liver enzymes.

Results

The UV absorption in phycocyanin was 620 nm but in phycocyanin nanoparticles was 420 nm. For fluorometry, the maximum emission peak of phycocyanin was 660 nm and that of phycocyanin-AgNO3 nanoparticles was 580 nm. PC-AgNp showed greater antibacterial effects than phycocyanin. In animal studies, it was found that the platelet count in both groups was higher than the control group. Red blood cells and white blood cells had changes. AST and ALT levels increased in both phycocyanin and nanoparticle groups and ALK levels decreased in both groups compared to the control group.

Conclusions

Examination of antibacterial activity showed that PC-AgNp showed more antibacterial effects than PC. Also, in the study of the effect of PC and NP-PC, accumulation of PC and C-Np in mice also altered blood cells and liver enzymes in rats.

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.

Phycobiliproteins: Structural aspects, functional characteristics, and biotechnological perspectives

Phycobiliproteins (PBPs) are fluorescent proteins of various colors, including fuchsia, purple-blue and cyan, that allow the capture of light energy in auxiliary photosynthetic complexes called phycobilisomes (PBS). PBPs have several highly preserved structural and physicochemical characteristics. In the PBS context, PBPs function is capture luminous energy in the 450-650 nm range and delivers it to photosystems allowing photosynthesis take place. Besides the energy harvesting function, PBPs also have shown to have multiple biological activities, including antioxidant, antibacterial and antitumours, making them an interesting focus for different biotechnological applications in areas like biomedicine, bioenergy and scientific research. Nowadays, the main sources of PBPs are cyanobacteria and micro and macro algae from the phylum Rhodophyta. Due to the diverse biological activities of PBPs, they have attracted the attention of different industries, such as food, biomedical and cosmetics. This is why a large number of patents related to the production, extraction, purification of PBPs and their application as cosmetics, biopharmaceuticals or diagnostic applications have been generated, looking less ecological impact in the natural prairies of macroalgae and less culture time or higher productivity in cyanobacteria to satisfy the markets and applications that require high amounts of these molecules. In this review, we summarize the main structural characteristics of PBPs, their biosynthesys and biotechnological applications. We also address current trends and future perspectives of the PBPs market.

Single-step purified R-phycoerythrin transmits cellular imaging functionalities in vitro

A single-step and rapid chromatographic method-based purification of Gracilaria corticata (J. Agardh) R-phycoerythrin (R-PE) was attained using polyacrylamide gel electrophoresis (PAGE) technique without affecting structural integrity. The purified R-PE had a characteristic UV-Vis spectrum with three absorbance maxima at 496, 535, and 565 nm, and fluorescence at 575 nm. R-PE was obtained with a purity index of 4.2 and a recovery yield of 44.3%. SDS-PAGE analysis exhibited three sub-units i.e., 18, 21, and 31 kDa, which corresponds to α, β, and γ, respectively. This report's purification process was considered less time-consuming and could be efficiently applied to purify phycobiliproteins. The purified R-PE showed optimal stability up to 6 h at pH 7.0 when exposed to light (3000 lx), while the temperature at which the maximum stability was retained was at 20 °C. The cellular imaging property of R-PE was effectively implemented to evaluate its credentials without affecting the cell proliferation of Vero and Hep-2 cell lines with the higher IC50 concentrations in vitro. Under fluorescence microscopy and flow cytometry analysis, purified R-PE displayed the characteristic affinity towards cell imaging functions in preliminary in vitro studies.

Phycocyanin, a super functional ingredient from algae; properties, purification characterization, and applications

Phycocyanins (PCYs) are a group of luxuriant bioactive compounds found in blue-green algae with an estimated global market of about US$250 million within this decade. The multifarious markets of PCYs noted by form (e.g. powder or aqueous forms), by grade (e.g. analytical, cosmetic, or food grades), and by application (such as biomedical, diagnostics, beverages, foods, nutraceuticals and pharmaceuticals), show that the importance of PCYs cannot be undermined. In this comprehensive study, an overview on PCY, its structure, and health-promoting features are diligently discussed. Methods of purification including chromatography, ammonium sulfate precipitation and membrane filtration, as well as characterization and measurement of PCYs are described. PCYs could have many applications in food colorants, fluorescent markers, nanotechnology, nutraceutical and pharmaceutical industries. It is concluded that PCYs offer significant potentials, although more investigations regarding its purity and safety are encouraged.

Bioactive substances and potentiality of marine microalgae

Microalgae is one of the most important components in the aquatic ecosystem, and they are increasingly used in food and medicine production for human consumption due to their rapid growth cycle and survival ability in the harsh environment. Now, the exploration of microalgae has been gradually deepening, mainly focused on the field of nutrition, medicine, and cosmetics. A great deal of studies has shown that microalgae have a variety of functions in regulating the body health and preventing disease, such as nitrogen fixation, antitumor, antivirus, antioxidation, anti-inflammatory, and antithrombotic. Furthermore, microalgae can synthesize various high-valued bioactive substances, such as proteins, lipids, polysaccharides, and pigments. In this paper, we have briefly reviewed the research progress of main bioactive components in microalgae, proteins, lipids, polysaccharides, pigments, and other nutrients included, as well as their present application situation. This paper can provide the guidance for research and development of industrial production of microalgae.

Enhancement of Phycobiliprotein Accumulation in Thermotolerant Oscillatoria sp. through Media Optimization

Phycobiliproteins (PBPs) are a group of brilliant pigment proteins found in cyanobacteria and red algae; their synthesis and accumulation depend on several factors such as the type of strain employed, nutrient concentration, light intensity, light regimes, and others. This study evaluates the effect of macronutrients (citrate buffer, NaNO₃, K₂HPO₄, MgSO₄, CaCl₂, Na₂CO₃, and EDTA) and the concentration of trace metals in BG-11 media on the accumulation of PBPs in a thermotolerant strain of Oscillatoria sp. The strain was grown in BG-11 media at 28 °C with a light:dark cycle of 12:12 h at 100 μmol m^-2 s^-1 for 15 days, and the effect of nutrients was evaluated using a Plackett-Burman Design followed by optimization using a response surface methodology. Results from the concentration of trace metals show that it can be reduced up to half-strength in its initial concentration without affecting both biomass and PBPs. Results from the Plackett-Burman Design revealed that only NaNO₃, Na₂CO₃, and K₂HPO₄ show a significant increase in PBP production. Optimization employed a central Non-Factorial Response Surface Design with three levels and four factors (3⁴) using NaNO₃, Na₂CO₃, K₂HPO₄, and trace metals as variables, while the other components of BG-11 media (citrate buffer, MgSO₄, CaCl₂, and EDTA) were used in half of their initial concentration. Results from the optimization show that interaction between Na₂CO₃ and K₂HPO₄ highly increased PBPs' concentration, with values of 15.21, 3.95, and 1.89 (% w/w), respectively. These results demonstrate that identifying and adjusting the concentration of critical nutrients can increase the concentration of PBPs up to two times for phycocyanin and allophycocyanin while four times for phycoerythrin. Finally, the reduction in non-key nutrients' concentration will reduce the production costs of colorants at an industrial scale and increase the sustainability of the process.

Symbioses of Cyanobacteria in Marine Environments: Ecological Insights and Biotechnological Perspectives

Cyanobacteria are a diversified phylum of nitrogen-fixing, photo-oxygenic bacteria able to colonize a wide array of environments. In addition to their fundamental role as diazotrophs, they produce a plethora of bioactive molecules, often as secondary metabolites, exhibiting various biological and ecological functions to be further investigated. Among all the identified species, cyanobacteria are capable to embrace symbiotic relationships in marine environments with organisms such as protozoans, macroalgae, seagrasses, and sponges, up to ascidians and other invertebrates. These symbioses have been demonstrated to dramatically change the cyanobacteria physiology, inducing the production of usually unexpressed bioactive molecules. Indeed, metabolic changes in cyanobacteria engaged in a symbiotic relationship are triggered by an exchange of infochemicals and activate silenced pathways. Drug discovery studies demonstrated that those molecules have interesting biotechnological perspectives. In this review, we explore the cyanobacterial symbioses in marine environments, considering them not only as diazotrophs but taking into consideration exchanges of infochemicals as well and emphasizing both the chemical ecology of relationship and the candidate biotechnological value for pharmaceutical and nutraceutical applications.

Phycocyanin from Arthrospira platensis as Potential Anti-Cancer Drug: Review of In Vitro and In Vivo Studies

The application of cytostatic drugs or natural substances to inhibit cancer growth and progression is an important and evolving subject of cancer research. There has been a surge of interest in marine bioresources, particularly algae, as well as cyanobacteria and their bioactive ingredients. Dried biomass products of Arthrospira and Chlorella have been categorized as “generally recognized as safe” (GRAS) by the US Food and Drug Administration (FDA). Of particular importance is an ingredient of Arthrospira: phycocyanin, a blue-red fluorescent, water-soluble and non-toxic biliprotein pigment. It is reported to be the main active ingredient of Arthrospira and was shown to have therapeutic properties, including anti-oxidant, anti-inflammatory, immune-modulatory and anti-cancer activities. In the present review, in vitro and in vivo data on the effects of phycocyanin on various tumor cells and on cells from healthy tissues are summarized. The existing knowledge of underlying molecular mechanisms, and strategies to improve the efficiency of potential phycocyanin-based anti-cancer therapies are discussed.

A hybrid biomaterial of biosilica and C-phycocyanin for enhanced photodynamic effect towards tumor cells

Intricate mesoporous biosilica has many biomedical applications as a nanocarrier. However, its potential use in photodynamic therapy (PDT) has received little attention. This work reports the first fabrication of bio-engineered materials by covalently conjugating C-phycocyanin (C-PC), a natural photosensitizer, to biosilica for the PDT of tumor-associated macrophages. The resulting hybrid material showed outstanding photodynamic activity under 620 nm laser irradiation. Furthermore, it enhanced the relatively weak photodynamic effect of C-PC. This study also explored methods of biofunctionalizing biosilica for cancer phototherapy, a new pharmacological application of non-toxic C-PC.

Alleviation of carbon tetrachloride-induced hepatocellular damage and oxidative stress in rats by Anabaena oryzae phycocyanin

Phycocyanin isolated from Anabaena biomass was in-vitro assayed for its antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] free radical, revealing maximum activities amounting to 77 and 80% at 1,000 µg/ml and SC₅₀ values about 96 and 111 µg/ml, respectively. A biological experiment was conducted, involving 40 male Wistar Albino rats, divided into five groups. Group I received only the basal diet as a normal control, while groups II, III, IV, and V were administrated intraperitoneal (IP) injection of a single dose of CCl₄ (50% in corn oil) at 0.5 ml/kg body weight. Subsequently, groups II, III, IV, and V received phycocyanin at 0.0, 25, 50, and 100 mg/kg body weight/day. CCl₄ induced considerable increases (p < .05) in the levels of serum ALT, AST, urea and creatinine, total lipid, and triglycerides coupled with significant reductions (p < .05) in serum antioxidant enzymes and some liver histopathological deformations compared to the negative control (group 1). Administration of Anabaena oryzae phycocyanin can counteract these CCl₄ -induced changes. PRACTICAL APPLICATIONS: Phycocyanin isolated from Anabaena has beneficial effects such as the antioxidant, antibacterial, anticancer, and hepatoprotective effect. Phycocyanin may play a key role in alleviating oxidative stress, artificially induced by carbon tetrachloride in Albino rats, to ultimately determine its capacity to serve as a natural antioxidant for food and health applications.

Phycocyanin of marine Oscillatoria sp. inhibits lipoxygenase by protein-protein interaction-induced change of active site entry apace: A model for non-specific biofunctions of phycocyanins

An overview of the biological properties of phycocyanin (PC) amply illustrates that it may not have any specific functional feature towards any system at which it may elicit a specific function, but for the molecular interactions. Nevertheless, based on existing evidences, it is hypothesized that PC has more than one functional target with the interacting systems; therefore, it has diversity of effects. The mechanism of PC action remains elusive of a comprehensive idea. The present investigation focuses on the pro inflammatory enzyme, lipoxygenase (LOX) inhibiting property of PC purified from Oscillatoria sp. Enzyme kinetics studies show that the molecular composite of PC is required for its inhibition shown on LOX. Isothermal titration calorimetric study proves that one molecule of PC interacts with two molecules of LOX. Molecular dynamics simulation study pertaining to PC-LOX interactions shows it to be appropriate as a model to give molecular mechanistic insight into the varied biological properties of PC, demonstrated elsewhere in experimental studies including animal model studies. It explains that the PC-LOX interaction is of a function-freezing, protein-protein interaction in nature. The wide spectrum of properties of PC might be due to its function as a powerful protein hub showing non-specific protein-protein interactions.

One structure, multiple features: The phycocyanin in biotechnology

Phycocyanine (PC) is a water-soluble, non-toxic and bioactive (antioxidant, anti-inflammatory, antitumor, etc.) phycobiliprotein isolated, mainly, from cyanobacteria. Due to its several properties, PC is considered to be a rising biomolecule for Industrial exploitation, and has become an important research axis in order to promote its production, and optimize its biotechnological applications. The aim of this review article was to discuss the basic, and recent properties and applications of PC, and to bring together data on various aspects of PC stabilization, and PC nanopar-ticles formulation. In addition, an overview of the main structural characteristics and process-ses of PC extraction and purification were also discussed. The recent scientific research findings concluded that PC is a promising both functional, and bioactive additive in industry, especially, in food as a dye, in imaging as a fluorescent labeling agent, and in the phar-maceutical and nano-pharmaceutical field as a bioactive molecule and nanopar-ticles, particularly, due to it antitumor capacity. Phycocyanine is, thus, a promising bio-active molecules in pharmacological, and medical fields.

Potential Therapeutic Applications of C-Phycocyanin

BACKGROUND

Cancer and other disorders such as inflammation, autoimmune diseases and diabetes are the major health problems observed all over the world. Therefore, identifying a therapeutic target molecule for the treatment of these diseases is urgently needed to benefit public health. C-Phycocyanin (C-PC) is an important light yielding pigment intermittently systematized in the cyanobacterial species along with other algal species. It has numerous applications in the field of biotechnology and drug industry and also possesses antioxidant, anticancer, antiinflammatory, enhanced immune function, including liver and kidney protection properties. The molecular mechanism of action of C-PC for its anticancer activity could be the blockage of cell cycle progression, inducing apoptosis and autophagy in cancer cells.

OBJECTIVES

The current review summarizes an update on therapeutic applications of C-PC, its mechanism of action and mainly focuses on the recent development in the field of C-PC as a drug that exhibits beneficial effects against various human diseases including cancer and inflammation.

CONCLUSION

The data from various studies suggest the therapeutic applications of C-PC such as anti-cancer activity, anti-inflammation, anti-angiogenic activity and healing capacity of certain autoimmune disorders. Mechanism of action of C-PC for its anticancer activity is the blockage of cell cycle progression, inducing apoptosis and autophagy in cancer cells. The future perspective of C-PC is to identify and define the molecular mechanism of its anti-cancer, anti-inflammatory and antioxidant activities, which would shed light on our knowledge on therapeutic applications of C-PC and may contribute significant benefits to global public health.

Algae-Derived Bioactive Compounds with Anti-Lung Cancer Potential

Lung cancer is one of the major causes of death worldwide. Natural molecules with anti-lung cancer potential are of a great interest and considered as very promising alternative to substitute or enhance the efficiency of the conventional drugs. Recently, algae as source of high value-added compounds are considered as very promising source of these bioactive molecules. These are secondary metabolites that consist mainly of derivatives of peptides, carbohydrates, and lipids with various structures. Accordingly, various mechanisms by which different algae molecules demonstrate attenuation of tumor angiogenesis were stated and discussed. The mode of action of the algae bioactives is closely related to their nature and chemical structure. Furthermore, this literature review considers the synergistic effect between microalgae bioactives and conventional drugs and discuss the economic feasibility of producing microalgae bioactives at large scale to conclude with some future perspectives related to algae-based drug discovery.

Ultrasound-Assisted Extraction and Assessment of Biological Activity of Phycobiliprotein-Rich Aqueous Extracts from Wild Cyanobacteria (Aphanizomenon flos-aquae)

Cyanobacteria are photosynthetic microorganisms that are considered as an important source of bioactive metabolites, among which phycobiliproteins (PBPs) are a class of water-soluble macromolecules of cyanobacteria with a wide range of applications. Massive proliferation of cyanobacteria can lead to excessive surface water blooms, of which removal, as a management measure, should be prioritized. In this study, the utilization of wild cyanobacteria biomass (Aphanizomenon flos-aquae) for extraction of phycobiliproteins is reported. Extraction of phycobiliproteins by conventional methods, such as homogenization, freeze-thaw cycles, and solid-liquid extraction, were optimized prior to ultrasound-assisted extraction. Standardization of ultrasonication for different parameters, such as ultrasonication amplitude (38, 114, and 190 μm) and ultrasonication time (1, 5.5, and 10 min), was carried out using a central composite design and response surface methodology for each of the primary techniques. A substantial increase on the individual and total phycobiliprotein yields was observed after ultrasonic treatment. The highest total PBP yield (115.37 mg/g of dry weight) was observed with samples treated with a homogenizer (30 min, 30 °C, and 1 cycle) combined with ultrasound treatment (8.7 min at 179 μm). Moreover, in vitro antioxidant capacity was observed for the obtained extracts in the Folin-Ciocalteu and ABTS^* + assays. In addition, a cytotoxic effect against C6 glioma cells was observed for A. flos-aquae PBPs. Conclusively, wild cyanobacteria could be considered as an alternative feedstock for recovery of PBPs.

Targeted delivery and apoptosis induction of trans-resveratrol-ferulic acid loaded chitosan coated folic acid conjugate solid lipid nanoparticles in colon cancer cells

The present study is aimed to study and to evaluate the colon cancer targeting efficacy of chitosan-coated-trans-resveratrol (RSV) and ferulic acid (FER) loaded SLNs (solid lipid nanoparticles) that conjugated with folic acid (FA) (C-RSV-FER-FA-SLNs) in suitable models (in vitro). The FA conjugation is performed using co-encapsulation method of stearic acid. Similarly, the prepared SLNs are exhibited better stability even under acidic conditions to exhibit their potentials to use as drug delivery system. Further, the optimized formulations (SLNs) are tested for physiochemical characterizations, which include FTIR, XRD, ¹HNMR, particle size, zeta potential, and drug release. In vitro anti-cancer studies using HT-29 cells including, fluorescence staining, flow cytometry, and western blot analysis revealed that the C-RSV-FER-FA-SLNs effectively involved and increased cytotoxicity in cancer cells that leads to induction of apoptosis as compared to free RSV-FER. Thus, it is reported that, the good stability under acidic conditions of this C-RSV-FER-FA-SLNs may serve as a promising candidate for novel nanodrug formulations in cancer therapy.

Phycocyanin Ameliorates Radiation-Induced Acute Intestinal Toxicity by Regulating the Effect of the Gut Microbiota on the TLR4/Myd88/NF-κB Pathway

BACKGROUND

Radiation-induced gastrointestinal syndrome, including nausea, diarrhea, and dehydration, contributes to morbidity and mortality after medical or industrial radiation exposure, which seriously affects patient quality of life after treatment. No safe and effective radiation countermeasure has been approved for clinical therapy. In this study, we aimed to investigate the potential protective effects of phycocyanin (PC) against radiation-induced acute intestinal injury.

MATERIALS AND METHODS

C57BL/6 mice were orally administered 50 mg/kg PC once per day for 1 month before exposure to total-abdominal x-ray irradiation at a single dose of 12 Gy. The effects of PC on intestinal histopathology and integrity, gut microbiota, lipopolysaccharides (LPS), inflammatory cytokines, and Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (Myd88)/nuclear factor κB (NF-κB) signaling were evaluated.

RESULTS

Severe histopathological damage, such as intestinal mucosal epithelial cell apoptosis, necrosis, and nuclear rupture, was most clearly observed 24 hours after total-abdominal x-ray irradiation. Intestinal integrity was damaged by irradiation, which manifested in reduced levels of the tight-junction proteins Claudin-1, Occludin, and zonula occludens-1(ZO-1). PC pretreatment significantly ameliorated radiation-induced intestinal injury. PC also modulated the gut microbiota composition, increasing the proportion of beneficial bacteria and decreasing that of harmful bacteria, which in turn lowered LPS levels and suppressed TLR4/Myd88/NF-κB pathway activation. Finally, levels of corresponding inflammatory cytokines, including tumor necrosis factor α and interleukin-6, were also downregulated.

CONCLUSION

PC protects against mouse intestinal injury from high-dose radiation by regulating the effect of the gut microbiota on the TLR4/Myd88/NF-κB pathway, suggesting PC as a promising natural radiation countermeasure.

Spirulina extract enriched for Braun-type lipoprotein (Immulina®) for inhibition of 4T1 breast tumors' growth and metastasis

Spirulina platensis extracts have exhibited considerable anti-cancer effects. To investigate the efficacy of the Spirulina extract enriched for Braun-type lipoprotein (Immulina®) for breast cancer treatment, 4T1 breast tumor-bearing mice were treated with 40 mg/kg Immulina® daily and the tumors' growth and metastasis were assessed. Also, CD4, CD8, and CD56 staining were performed to investigate the Immulina® effect on the immune cells' recruitment to the tumors by immunohistochemistry. Immulina® could significantly (P < 0.001) inhibit 4T1 breast tumors' growth. Immulina®-treated group exhibited a 63% decrease in the tumors' volume in comparison with control (P < 0.001). Also, Immulina® could significantly (P < 0.001) decrease metastatic burden at the vital organs as 68% and 61% decrease in the liver and lungs metastatic colonies were observed, respectively. Also, Immulina® could increase mean survival time of the tumor-bearing mice for 29 days. The Spirulina-treated mice tumors contained significantly more infiltrated NK, CD4+, and CD8+ T lymphocytes in comparison with control. Taking together, Immulina® can be a safe anti-cancer supplement with the ability to cause direct apoptosis to the cancer cells and activate the immune system against tumor. This supplement with natural origin seems to have bright future to help breast cancer patients.

Targeted delivery of phycocyanin for the prevention of colon cancer using electrospun fibers

Phycocyanin (PC), a water-soluble biliprotein, exhibits potent anti-colon cancer properties. However, its application in functional foods is limited by the poor stability and low bioavailability of PC. In this study, we successfully encapsulated PC by coaxial electrospinning. The colon targeted release of PC was achieved with retention of the antioxidant activity of PC. The PC-loaded electrospun fiber mat (EFM) obtained inhibited HCT116 cell growth in a dose-dependent and time-dependent manner. In particular, the PC-loaded EFM exerted its anti-cancer activity by blocking the cell cycle at the G0/G1 phase and inducing cell apoptosis involving the decrease of Bcl-2/Bax, activation of caspase 3 and release of cytochrome c. This study suggests that co-axial electrospinning is an efficient and effective way to deliver PC and improve its bioavailability; thus, it represents a promising approach for encapsulating functional ingredients for colon cancer prevention.

C-Phycocyanin elicited antitumor efficacy via cell-cycle arrest, apoptosis induction, and invasion inhibition in esophageal squamous cell carcinoma

Objectives: Mounting evidence has demonstrated that C-Phycocyanin (C-PC) exhibits marked antitumor activity in a wide type of tumors, such as pancreas cancer, breast carcinoma, lung cancer, and colon cancer. The current study aimed to confirm the antitumor efficacy of C-PC in esophageal squamous cell carcinoma (ESCC). Methods: The efficacy of C-PC was evaluated against the proliferation of ESCC cell lines EC9706 and EC1 by CCK-8 kit and in a mice model of ESCC EC9706. Cell cycle and apoptosis were investigated by flow cytometry, and cell invasion was determined via transwell chamber. Protein expression was examined by Western blots. Results: We found that C-PC exhibited anti-proliferation ability in a time-dependent manner and a dose-dependent manner in ESCC EC9706 and EC1 cells. Besides, C-PC markedly arrested cell cycle in the G0/G1 phase, induced cell apoptosis and suppressed cell invasion ability in both EC9706 and EC1 cells (p < .01). Notably, C-PC evoked the elevations of Bax, PARP, and cleaved-caspase-3 protein, but reduced cyclin D1, CDK4, Bcl-2, MMP-2, and MMP-9 expression levels. Further investigation from in vivo experiment revealed that C-PC displayed significant antitumor efficacy in the xenografted EC9706 model. Conclusions: Our data presented herein suggest C-PC exerts antitumor efficacy in ESCC.

Optimization, isolation, characterization and hepatoprotective effect of a novel pigment-protein complex (phycocyanin) producing microalga: Phormidium versicolorNCC-466 using response surface methodology

In our study, we focused on the optimization; antioxidant and hepatoprotective potentials of novel pigment-protein complex(C-PC) isolated from Phormidium versicolor against cadmium induced liver injury in rats. From analysis, the C-PC extraction parameters were optimized using the response surface methodology (RSM) for optimal recoveries of C-PC extraction. For analysis, the optimum operational conditions for maximizing phycocyanins concentration (67.45mg/g DM) were found to be water/solid 2, temperature 32.5°C and pH7.2.This pigment was identified using HPLC and FTIR analysis. In addition, the molecular masses of α and β subunits were 17 and 19kDa. Scavenging activity of superoxide anion, hydroxyl, nitric oxide radicals and metal chelating in vitro results indicated that C-PC has an excellent capacity as antioxidant. In vivo study, C-PC significantly prevented cadmium-induced elevation of ALAT, ASAT and bilirubin levels in rats. The histopathological observations supported the results serum enzymes assays. The results of this study revealed that C-PC has significant hepatoprotective potential. C-PC (50mgkg^-1 body weight) significantly enhanced the levels of antioxidant enzymes. It can be concluded that C-PC possesses prevention action against hepatotoxicity caused by cadmium.

C-Phycocyanin Suppresses the In Vitro Proliferation and Migration of Non-Small-Cell Lung Cancer Cells through Reduction of RIPK1/NF-κB Activity

Phycocyanin, derived from Spirulina platensis, is a type of natural antineoplastic marine protein. It is known that phycocyanin exerts anticancer effects on non-small-cell lung cancer (NSCLC) cells, but its underlying mechanism has not been elucidated. Herein, the antitumor function and regulatory mechanism of phycocyanin were investigated in three NSCLC cell lines for the first time: H358, H1650, and LTEP-a2. Cell phenotype experiments suggested that phycocyanin could suppress the survival rate, proliferation, colony formation, and migration abilities, as well as induce apoptosis of NSCLC cells. Subsequently, transcriptome analysis revealed that receptor-interacting serine/threonine-protein kinase 1 (RIPK1) was significantly down-regulated by phycocyanin in the LTEP-a2 cell, which was further validated by qRT-PCR and Western blot analysis in two other cell lines. Interestingly, similar to phycocyanin-treated assays, siRNA knockdown of RIPK1 expression also resulted in growth and migration inhibition of NSCLC cells. Moreover, the activity of NF-κB signaling was also suppressed after silencing RIPK1 expression, indicating that phycocyanin exerted anti-proliferative and anti-migratory function through down-regulating RIPK1/NF-κB activity in NSCLC cells. This study proposes a mechanism of action for phycocyanin involving both NSCLC apoptosis and down regulation of NSCLC genes.

Phycocyanin Exerts Anti-Proliferative Effects through Down-Regulating TIRAP/NF-κB Activity in Human Non-Small Cell Lung Cancer Cells

Phycocyanin is a type of marine functional food additive, exerting a health care efficacy with no side effects. It has been shown that phycocyanin possesses anticancer function in non-small cell lung cancer (NSCLC) cells, but the underlying regulatory mechanism still remains unclear. Further investigation on the antineoplastic mechanism of phycocyanin would provide useful information on NSCLC treatment. In this study, we explored the in vitro function and mechanism of phycocyanin in three typical NSCLC cell lines, H1975, H1650, and LTEP-a2, for the first time. Phenotypic experiments showed that phycocyanin significantly induced the apoptosis as well as suppressed the growth of NSCLC cells. Transcriptome analysis suggested that toll/interleukin 1 receptor domain-containing adaptor protein (TIRAP) was significantly down-regulated by phycocyanin. Strikingly, similar to phycocyanin-treated assays, siRNA knockdown of TIRAP expression also resulted in the anti-proliferative phenomenon in NSCLC cells. In addition, the activity of NF-κB signaling was also suppressed after silencing TIRAP expression, revealing that phycocyanin exerted anti-proliferative function through down-regulating TIRAP/NF-κB activity in NSCLC cells. Collectively, this study has laid a theoretical basis on the treatment of NSCLC and the potential utilization of marine functional products.

Effects of Carrageenan and Chitosan as Coating Materials on the Thermal Degradation of Microencapsulated Phycocyanin from Spirulina sp

Phycocyanin is a natural substance that can be used as an antioxidant and food colorant. The quality of phycocyanin deteriorates when it is exposed to heat, and such deterioration is evidenced by decreases in its antioxidant activity and color. Encapsulation, which introduces a coating material over a substance of interest, has been applied to prevent changes in substance quality. The objective of the present research is to evaluate the kinetics of thermal degradation of phycocyanin coated with carrageenan or chitosan. Encapsulated phycocyanin samples were exposed to temperatures of 40, 50, or 60 °C for 90 min, and kinetics of the resulting degradation was evaluated to determine changes in sample quality. The results showed that the thermal degradation of encapsulated phycocyanin at 40–60 °C follows first-order reaction kinetics with reaction rate constants (k) of 4.67–9.17 × 10–5 s-1 and 3.83–7.67 × 10–5 s-1 for carrageenan and chitosan, respectively, and that the k of encapsulated phycocyanin is slower than that obtained from samples without the coating materials (control). Encapsulation efficiencies (EE) of 68.66 % and 76.45 %, as well as loading capacities of 45.28 % and 49.16 %, were, respectively, obtained for carrageenan and chitosan.

Transcriptome Analysis of Phycocyanin-Mediated Inhibitory Functions on Non-Small Cell Lung Cancer A549 Cell Growth

Phycocyanin (PC), derived from cyanobacteria and Spirulina cells, is a type of natural antineoplastic marine protein. It has been reported that phycocyanin exerts an antitumor function in non-small cell lung cancer (NSCLC) cells, but the underlying mechanism has not been elucidated. In this research, a transcriptome study was performed to investigate the regulatory mechanisms of phycocyanin on human NSCLC A549 cells. The survival rate and proliferation ability of A549 cells were markedly reduced by phycocyanin, along with abnormal morphologic changes. The transcriptome analysis showed that 2970 genes were differentially expressed after phycocyanin treatment in A549 cells, including 1431 down-regulated and 1539 up-regulated genes. Gene ontology and KEGG analysis suggested that some classical pathways, such as Wnt, NF-κB, and PI3K-AKT signaling, were significantly enriched. Strikingly, protein–protein interaction (PPI) analysis showed that ubiquitin-C (UBC) occupied the highest degree (the highest number of interactions) in differential genes, indicating that it might play a key role in the phycocyanin-mediated regulatory process in A549 cells. Moreover, qRT-PCR results showed consistent expression trends of differential genes with transcriptome analysis. Consequently, this study has provided a theoretical basis for regulation of phycocyanin in A549 cells, which lays a foundation for the treatment of NSCLC.