The effects of dietary Spirulina platensis or curcumin nanoparticles on performance, body chemical composition, blood biochemical, digestive enzyme, antioxidant and immune activities of Oreochromis niloticus fingerlings.

CONTEXT: Recently, prioritize has been given to using natural phytogenic or nano compounds as growth promoters and immunostimulants in fish diets as an alternative to antibiotics. AIMS: The main propose of this trial was to determine the impact of supplementing diets with spirulina or curcumin nanoparticles on the performance and health indicators of Nile tilapia fingerlings. METHODS: In a 56-day feeding trial, 180 tilapia fingerlings were assigned into three main groups, as follows: 1st, control group, 2nd, Spirulina platensis (SP; 5 g kg-1 diet) and 3rd, curcumin nanoparticles (CUR-NPs; 30 mg kg-1 diet). KEY RESULTS: Incorporating tilapia diets with SP or CUR-NPs significantly improved performance, body chemical analysis, blood biochemical and hematological indices, digestive enzyme activities, and antioxidant and immunostimulant features compared to the control. CONCLUSION: Fortified tilapia diets with CUR-NPs or SP efficiently boost the productivity and health of Nile tilapia fingerlings. IMPLICATIONS: The research introduces new practical solutions for applying safe feed additives as alternatives to antibiotics in tilapia farming.

Effects of molecular structure and charge state on the foaming and emulsifying properties of Spirulina protein isolates.

Microalgae protein holds great potential for various applications in the food industry. However, the current knowledge regarding microalgae protein remains limited, with little information available on its functional properties. Furthermore, the relationship between its molecular structure and functional properties is not well defined, which limits its application in food processing. This study aims to addresses these gaps though an analysis of the emulsibility and foamability of various soluble protein isolates from two species of Spirulina (Arthospira platensis and Spirulina platensis), and the functional properties of Spirulina protein isolates in relation to its molecular structure and charge state. Results revealed that the degree of cross-linking and aggregation or folding and curling of protein tertiary structures was higher in the highly soluble Spirulina protein isolates (AP50% and SP50%) than in the low-solubility isolates (AP30% and SP30%). The foaming capacity (FC) of AP50% and SP50% was found to be lower than that of AP30% and SP30%. Spirulina protein isolates can stably adsorb at the air-water interface for at least 20 min and possessed good interfacial activity. A high pH value was found to promote cross-linking of protein particles at the oil-water interface, thereby reinforcing the internal network structure of emulsions and increasing viscosity. These findings provide preliminary insights for potential applications of Spirulina protein isolates in food production, especially towards quality improvement.

Phycocyanin from microalgae: A comprehensive review covering microalgal culture, phycocyanin sources and stability.

As food safety continues to gain prominence, phycocyanin (PC) is increasingly favored by consumers as a natural blue pigment, which is extracted from microalgae and serves the dual function of promoting health and providing coloration. Spirulina-derived PC demonstrates exceptional stability within temperature ranges below 45 °C and under pH conditions between 5.5 and 6.0. However, its application is limited in scenarios involving high-temperature processing due to its sensitivity to heat and light. This comprehensive review provides insights into the efficient production of PC from microalgae, covers the metabolic engineering of microalgae to increase PC yields and discusses various strategies for enhancing its stability in food applications. In addition to the most widely used Spirulina, some red algae and Thermosynechococcus can serve as good source of PC. The genetic and metabolic manipulation of microalgae strains has shown promise in increasing PC yield and improving its quality. Delivery systems including nanoparticles, hydrogels, emulsions, and microcapsules offer a promising solution to protect and extend the shelf life of PC in food products, ensuring its vibrant color and health-promoting properties are preserved. This review highlights the importance of metabolic engineering, multi-omics applications, and innovative delivery systems in unlocking the full potential of this natural blue pigment in the realm of food applications, provides a complete overview of the entire process from production to commercialization of PC, including the extraction and purification.

Effects of high dietary inclusion of Arthrospira platensis, either extruded or supplemented with a super-dosing multi-enzyme mixture, on broiler growth performance and major meat quality parameters.

BACKGROUND: This investigation assessed the effects of high dietary inclusion of Spirulina (Arthrospira platensis) on broiler chicken growth performance, meat quality and nutritional attributes. For this, 120 male broiler chicks were housed in 40 battery brooders (three birds per brooder). Initially, for 14 days, a standard corn and soybean meal diet was administered. Subsequently, from days 14 to 35, chicks were assigned to one of the four dietary treatments (n = 10 per treatment): (1) control diet (CTR); (2) diet with 15% Spirulina (SP); (3) diet with 15% extruded Spirulina (SPE); and (4) diet with 15% Spirulina plus a super-dosing enzymes supplement (0.20% pancreatin extract and 0.01% lysozyme) (SPM). RESULTS: Throughout the experimental period, both SP and SPM diets resulted in decreased final body weight and body weight gain compared to control (p < 0.001), with the SPE diet showing comparable results to CTR. The SPE diet prompted an increase in average daily feed intake (p = 0.026). However, all microalga treatments increased the feed conversion ratio compared to CTR. Dietary inclusion of Spirulina notably increased intestinal content viscosity (p < 0.010), which was mitigated by the SPM diet. Spirulina supplementation led to lower pH levels in breast meat 24 h post-mortem and heightened the b* colour value in both breast and thigh meats (p < 0.010). Furthermore, Spirulina contributed to an increased accumulation of total carotenoids, n-3 polyunsaturated fatty acids (PUFA), and saturated fatty acids (SFA), while diminishing n-6 PUFA, thus altering the n-6/n-3 and PUFA/SFA ratios favourably (p < 0.001). However, it also reduced zinc concentration in breast meat (p < 0.001). CONCLUSIONS: The findings indicate that high Spirulina levels in broiler diets impair growth due to increased intestinal viscosity, and that extrusion pre-treatment mitigates this effect. Despite reducing digesta viscosity, a super-dosing enzyme mix did not improve growth. Data also indicates that Spirulina enriches meat with antioxidants and n-3 PUFA but reduces α-tocopherol and increases saturated fats. Reduced zinc content in meat suggests the need for Spirulina biofortification to maintain its nutritional value.

Enhancing phycocyanin yield from Spirulina sp. under salt stress using various extraction methods.

Phycocyanin, a blue-coloured pigment, predominantly found and derived from Spirulina sp., has gained researchers' interest due to its vibrant hues and other attractive properties like antioxidant and anti-microbial. However, the lack of reliable and sustainable phycocyanin extraction strategies without compromising the quality has hindered the scaling up of its production processes for commercial purposes. Here in this study, phycocyanin was extracted from wet and dry biomass Spirulina sp., using three different physical cell disruption methods (ultrasonication, homogenization, and freeze-thaw cycles) combined with two different buffers (phosphate buffer and acetate buffer) and water (as control). The result showed that the freeze-thaw method combined with acetate buffer produced the highest yield (25.013 ± 2.572 mg/100 mg) with a purity ratio of 0.806 ± 0.079. Furthermore, when subjected to 30% w/v salt stress, 1.9 times higher phycocyanin yield with a purity ratio of 1.402 ± 0.609 was achieved using the previously optimized extraction method.

Probiotics from kefir: Evaluating their immunostimulant and antioxidant potential in the carpet shell clam (Ruditapesdecussatus).

This study aimed to investigate the impact of incorporating kefir into the diet on biometric parameters, as well as the immune and antioxidant responses of the carpet shell clam (Ruditapes decussatus) after an experimental infection by Vibrio alginolyticus. Clams were divided into a control group and a treated group. The control group was fed on spirulina (Arthrospira platensis) alone. While, the treated group was fed on spirulina supplemented with 10% dried kefir. After 21 days, clams were immersed in a suspension of V. alginolyticus 5 × 105 CFU mL -1 for 30 min. Seven days after experimental infection, survival was 100% in both groups. The obtained results showed a slight increase in weight and condition index in clams fed with kefir-supplemented diet for 21 days compared to control clams. Regarding antioxidant responses, the treated group showed higher superoxide dismutase activity compared to the control group. However, the malondialdehyde level was lower in the treated clams than in the control. In terms of immune parameters, the treated group showed slightly elevated activities of phenoloxidase, lysozyme and alkaline phosphatase, whereas a decreased lectin activity was observed compared to the control group. The obtained results suggest that kefir enhanced both the antioxidant and immune response of infected clams.

Unraveling the Anti-Aging Properties of Phycocyanin from the Cyanobacterium Spirulina (Arthrospira platensis).

In recent years, marine natural products have become one of the most important resources of novel lead compounds for critical diseases associated with age. Spirulina, a dietary supplement made from blue-green algae (cyanobacteria: scientific name Arthrospira platensis), is particularly rich in phycocyanin, a phycobiliprotein, which accounts for up to 20% of this cyanobacterium's dry weight and is considered responsible for its anti-cancer, anti-inflammatory and antioxidant activities. Although the anti-aging activity of phycocyanin has been investigated, how exactly this compound works against aging remains elusive. The aim of our research is to use the yeast Saccharomyces cerevisiae as a model organism to investigate the anti-aging properties of phycocyanin from A. platensis. Our results show that phycocyanin has a powerful anti-aging effect, greatly extending the chronological life span of yeast cells in a dose-dependent way, as the effect was also pronounced when cells were grown in SD medium under calorie restriction conditions (0.2% glucose). Both ROS and accumulation of dead cells were followed by staining chronologically aged cells with dihydrorhodamine 123 (DHR123) and propidium iodide (PI). Interestingly, we found that most of the aged phycocyanin-treated cells, which were unable to form colonies, were actually ROS+/PI-. Finally, we show that the moment in which phycocyanin is added to the culture does not substantially influence its effectiveness in counteracting chronological aging.

The Impact of Different Drying Methods on the Metabolomic and Lipidomic Profiles of Arthrospira platensis.

Drying is an inseparable part of industrial microalgae production. In this work, the impacts of eight different drying methods on the metabolome and lipidome of Arthrospira platensis were investigated. The studied drying methods were freeze drying (FD), sun drying (SD), air drying at 40 and 75 °C (AD' and AD″), infrared drying at 40 and 75 °C (IRD' and IRD″), and vacuum drying at 40 and 75 °C (VD' and VD″). Results gathered by reversed-phase liquid chromatography separation coupled with high-resolution tandem mass spectrometry with electrospray ionization (RP-LC-ESI-Orbitrap HRMS/MS) analysis allowed researchers to identify a total of 316 metabolites (including lipids) in aqueous and ethanolic extracts. The compounds identified in ethanolic extracts were mainly lipids, such as neutral and polar lipids, chlorophylls and carotenoids, while the compounds identified in the aqueous extracts were mainly amino acids and dipeptides. Among the identified compounds, products of enzymatic and chemical degradation, such as pyropheophytins, monoacylglycerols and lysophosphatidylcholines were also identified and their amounts depended on the drying method. The results showed that except for FD method, recognized as a control, the most protective method was AD'. Contrary to this, VD' and VD″, under the conditions used, promoted the most intense degradation of valuable metabolites.

Extraction, structural characterization, and antioxidant activity of polysaccharides from three microalgae.

Microalgal polysaccharides have received much attention due to their potential value in preventing and regulating oxidative damage. This study aims to reveal the mechanisms of regulating oxidative stress and the differences in the yield, structure, and effect of polysaccharides extracted from three microalgae: Golenkinia sp. polysaccharides (GPS), Chlorella sorokiniana polysaccharides (CPS), and Spirulina subsalsa polysaccharides (SPS). Using the same extraction method, GPS, CPS, and SPS were all heteropoly- saccharides composed of small molecular fraction: the monosaccharides mainly comprised galactose (Gal). Among the three, SPS had a higher proportion of small molecular fraction, and a higher proportion of Gal; thus it had the highest yield and antioxidant activity. GPS, CPS, and SPS all showed strong antioxidant activity in vitro, and showed strong ability to regulate oxidative stress, among which SPS was slightly higher. From the analysis of gene expression, the Nrf2-ARE signalling pathway was an important pathway for GPS, CPS, and SPS to regulate cellular oxidative stress. This study provides a theoretical foundation for further research on the utilization of microalgae polysaccharides and product development.

Comparative Analysis of Effect of Culture Conditions on Growth and C-Phycocyanin Production in Helical and Linear Spirulina.

Spirulina (Arthrospira and Spirulina spp.) has always been characterized by the helical trichomes, despite the existence of linear forms. A great debate is now open on the morphological flexibility of Spirulina, but it seems that both trichome morphology and C-phycocyanin (C-PC) concentrations are influenced by the culture conditions.This work compared the effect of some key growth factors (medium pH as well as its carbon, potassium, and salt contents) on the growth and C-PC concentration of helical and linear Spirulina strains. Further, two-phase strategies, including light and nitrogen variation, were applied to increase the in vivo C-PC accumulation into the trichomes. Results showed that high pH induced trichomes elongation and improved growth but decreased C-PC content (+ 65 and + 43% vs. -83 and -49%, for helical and linear strains, respectively). Variations in carbon and salt concentrations negatively impacted growth and C-PC content, even if the linear strain was more robust against these fluctuations. It was also interesting to see that potassium increasing improved growth and C-PC content for both strains.The variation of light wavelength during the enrichment phase (in the two-phase strategy) improved by 50% C-PC accumulation in trichomes, especially after blue lighting for 96 h. Similar result was obtained after 48 h of nitrogen reduction, while its removal from the medium caused trichomes disintegration. The current work highlights the robustness of linear Spirulina strain and presents an efficient and scalable way to increase C-PC in vivo without affecting growth.

A rapid one-step affinity purification of C-phycocyanin from Spirulina platensis.

The high-purity phycocyanin has a high commercial value. Most current purification methods of C-phycocyanin involve multiple steps, which are complicated and time-consuming. To solve the problem, this research was studied, and an efficient affinity chromatography purification for C-phycocyanin from Spirulina platensis was developed. Through molecular docking simulation, virtual screening of ligands was performed, and ursolic acid was identified as the specific affinity ligand, which coupled to Affi-Gel 102 gel via 1-ethyl (3-dimethylaminopropyl)-3-carbodiimide, hydrochloride as coupling agent. With this customized and synthesized resin, a high-efficiency one-step purification procedure for C-phycocyanin was developed and optimized, the purity was determined to be 4.53, and the yield was 69 %. This one-step purification protocol provides a new approach for purifying other phycobilin proteins.

Effects of the algae derivatives on performance, intestinal histomorphology, ileal microflora, and egg yolk biochemistry of laying Japanese quail.

We examined the effect of the Persian Gulf algae derivates, phycocyanin (PC) and fucoidan (FUC), on production performance, egg quality, intestinal histomorphology, ileal microflora, and egg yolk biochemistry of laying Japanese quail. A total of 250 six-wk-old Japanese quails with an average body weight of 215 ± 10 g were allocated to 5 treatments, 5 replicates and 10 birds in each replicate in a completely randomized design. The treatment groups received PC (from Spirulina platensis) and FUC (from brown seaweed) in their drinking water while control groups did not. Treatment groups received PC and FUC at 20 or 40 mg/L levels (denoted as PC20, PC40, FUC20, and FUC40, respectively). All birds were fed the same diet. All treatments significantly improved the percentage of hen day egg production (HDEP) (P = 0.002), egg mass (P = 0.002), and feed conversion ratio (FCR) (P = 0.022) but no difference was noted in egg weight (EW) and feed intake (FI). Different levels of PC and FUC significantly increased the thickness of eggshells (P = 0.022); however, the weight of the digestive tract (liver, spleen, proventriculus, gizzard, and pancreas) and oviduct was not affected. Algal derivates improved the villus height (P = 0.007) and crypt depth (P = 0.007) of the duodenum, as well as, the villus height (P = 0.005) and crypt depth (P = 0.026) of the jejunum. Both algal derivates positively affected the intestinal microflora (populations of Lactobacillus (P = 0.017), Coliform (P = 0.005), and Clostridium (P = 0.000)) whereas aerobic bacteria were unaffected. Yolk cholesterol P = 0.012) and yolk malondialdehyde P = 0.050) content were significantly reduced in experimental treatments compared to the control group. In conclusion, our results showed that the treatment of laying Japanese quails with algal derivates positively affects quail performance, intestinal morphology, intestinal microflora, and yolk cholesterol and malondialdehyde. Additional studies exploring optimal dosages and mechanisms of action is warranted to fully understand the scope of the algae derivates in poultry production.

Anti-Glycation Properties of Zinc-Enriched Arthrospira platensis (Spirulina) Contribute to Prevention of Metaflammation in a Diet-Induced Obese Mouse Model.

Advanced glycation end products (AGEs) exert a key pathogenic role in the development of obesity and insulin resistance. Thanks to its abundance in bioactive compounds, the microalga Arthrospira platensis (spirulina, SP) is proposed as a nutritional supplement. Here, we investigated the potential anti-glycating properties of SP enriched with zinc (Zn-SP) and the following impact on diet-induced metabolic derangements. Thirty male C57Bl6 mice were fed a standard diet (SD) or a high-fat high-sugar diet (HFHS) for 12 weeks, and a subgroup of HFHS mice received 350 mg/kg Zn-SP three times a week. A HFHS diet induced obesity and glucose intolerance and increased plasma levels of pro-inflammatory cytokines and transaminases. Zn-SP administration restored glucose homeostasis and reduced hepatic dysfunction and systemic inflammation. In the liver of HFHS mice, a robust accumulation of AGEs was detected, paralleled by increased expression of the main AGE receptor (RAGE) and depletion of glyoxalase-1, whereas Zn-SP administration efficiently prevented these alterations reducing local pro-inflammatory responses. 16S rRNA gene profiling of feces and ileum content revealed altered bacterial community structure in HFHS mice compared to both SD and HFHS + Zn-SP groups. Overall, our study demonstrates relevant anti-glycation properties of Zn-SP which contribute to preventing AGE production and/or stimulate AGE detoxification, leading to the improvement of diet-related dysbiosis and metabolic derangements.

A multiplex metabolomic approach for quality control of Spirulina supplement and its allied microalgae (Amphora & Chlorella) assisted by chemometrics and molecular networking.

Microalgae species are of economic importance regarded as "green gold" being rich in bioactive compounds. Spirulina and Chlorella are the most popular microalgal species and are marketed as healthy food supplements. At the same time, Amphora holds potential as a source of healthy lipids and essential fatty acids. Yet, there are considerable variations in their reported chemical composition, and less is known about their compositional differences. A multiplexed metabolomic approach was adopted for the quality control (QC) of Spirulina supplements and to compare its constitutive metabolome to Chlorella and Amphora. The adopted protocol comprised gas chromatography-mass spectrometry (GC-MS), ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-HRMS/MS), and ultraviolet-visible spectrophotometry (UV/Vis) for mapping their primary and secondary metabolome. Interestingly, UPLC-HRMS/MS analysis delineated the abundance of fatty acids in Amphora versus glycolipids enrichment in Spirulina, and porphyrins were the main pigments identified in Spirulina, with scarce occurrence in Chlorella. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) analysis of GC-MS data set revealed palmitic acid, 3-mannobiose, and glyceryl-glycoside as being most enriched in Spirulina, versus sucrose and leucine in Chlorella and Amphora, respectively. Despite being of low discriminatory potential, UV/Vis OPLS-DA modeling showed that Spirulina was distinguished with the UV absorbances of carotenoids and chlorophyll pigments, as indicated by its OPLS-DA derived S-plot. Our study provides a QC approach for the analysis of the microalgal species and poses alternative spectral and compositional markers for their discrimination.

Stability and bioactivities evaluation of analytical grade C-phycocyanin during the storage of Spirulina platensis powder.

C-phycocyanin (C-PC) is a natural high-value blue phycobiliprotein from Spirulina platensis, which has wide biological applications in food, pharmaceutical, and cosmetics. However, the freshness of S. platensis powder (SPP) materials and C-PC purification play critical roles in evaluating the stability and bioactivities of C-PC, which severely affect its commercial application. This study investigated the effect of spray-dried SPP freshness on the biofunctional activities of analytical grade C-PC (AGC-PC). The yield of AGC-PC extracted from spray-dried SPP could reach 101.88 mg/g (75% recovery ratio) after purification by reversed phase high-performance liquid chromatography (RP-HPLC) system. The half-life period (t1/2 ) of AGC-PC stability at 60°C and 8000 lux light could remain 171.70 min and 176.11 h within 6 months storage of spray-dried SPP. The emulsifying activity index (EAI) and foaming capacity (FC) of AGC-PC from fresh-dried SPP showed maximum values of 68.64 m2 /g and 252.9%, respectively. The EC50 of AGC-PC from fresh spray-dried SPP on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline -6-sulfonic acid (ABTS+·) scavenging activity could reach 63.76 and 92.93 mg/L, respectively. The EC50 of AGC-PC from fresh spray-dried SPP on proteinase inhibition and anti-lipoxygenase activity were 302.96 and 178.8 mg/L, respectively. The stability and biofunctional activities of AGC-PC remained stable within 6 months storage of SPP, and then rapidly decreased after 9 months storage due to the disintegration of the trimeric (αß)3 and hexameric (αß)6 forms of C-PC. It is concluded that the optimal storage period of SPP for preparation of AGC-PC in commercial use should be less than 6 months. PRACTICAL APPLICATION: The C-phycocyanin (C-PC) from dried Spirulina platensis powder (SPP) has been widely applied in food nutritional, florescent markers, pharmaceuticals, cosmetics, etc, due to its blue color, fluorescence, and antioxidant properties. However, the effect of dried SPP freshness on the stability and functional activity of C-PC has been rarely reported. This study found that the thermostability, photostability, emulsifying, antioxidant, and anti-inflammatory activities of analytical grade C-PC (AGC-PC) significantly decreased after 6 months storage of SPP. Based on investigations, we have proposed that the suitable storage time of dried SPP for preparation of AGC-PC in commercial application should be within 6 months.

Validation of a Toll-like Receptor (TLR)2/TLR1 Activation Assay for Biological Standardization of Arthrospira/Limnospira Immune-Enhancing Potency.

Arthrospira/Limnospira is a popular botanical dietary supplement throughout the world and has been consumed as a food product for hundreds of years. Ongoing efforts from our research group are focused on evaluating the utility of a Limnospira-derived oral supplement (Immulina) in promoting resilience against influenza viral infection. Like other botanical extracts, Immulina is inherently a complex matrix with variation in the levels of its chemical constituents. Therefore, to ensure therapeutic consistency for future scientific research and clinical studies, we are developing standardization technology using a bioassay and chemical markers. Braun-type lipoproteins, a class of macromolecules that activate the Toll-like receptor (TLR)2/TLR1 signaling pathway, have been identified as a major active component within Immulina. Based on the mechanism of action of the Braun-type lipoproteins, an in vitro bioassay was established using the HEK-Blue hTLR2/TLR1 cell line to quantitate the immune-enhancing potency of Immulina. The objective of the current research was to validate that bioassay for Immulina activity quantification using the U.S. FDA guidance document for botanical drug development and U.S. Pharmacopeia recommendations. System suitability, reference standards and defining potency units were established. Validation of performance parameters included precision, specificity, accuracy, linearity, and range. Validating this bioassay for Immulina activity provides a tool for ensuring product consistency and quantifying the potency of this botanical for use in future research as well as material in the consumer market.

Cooperative antioxidative defense of the blue-green alga Arthrospira (Spirulina) platensis under oxidative stress imposed by exogenous application of hydrogen peroxide.

Hydrogen peroxide (H2O2) is an environmentally-safe algaecide used to control harmful algal blooms and as a disinfectant in various domestic and industrial applications. It is produced naturally in sunny-water or as a by-product during growth, and metabolism of photosynthetic organisms. To assess the impact of H2O2 on Arthrospira platensis, several biochemical components, and antioxidant enzymes were analysed. The growth and biomass of A. platensis were decreased under the effect of H2O2. Whereas, the concentration up to 40 µM H2O2 non-significantly induced (at P < 0.05) the Chl a, C-phycocyanin (C-PC), total phycobiliprotein (PBP), and the radical scavenging activity of A. platensis. The half-maximal effective concentrations (EC50) for H2O2 were 57, 65, and 74 µM H2O2 with regards to the biomass yield, Chl a, and C-PC content, respectively. While, the total soluble protein, and soluble carbohydrates contents were significantly induced. However, the higher concentrations (60 and 80 µM) were lethal to these components, in parallel to the initiation of the lipid peroxidation process. Surprisingly, the carotenoids content was non-significantly increased by H2O2. Despite the relative consistency of catalase (CAT), the activities of superoxide dismutase (SOD) and peroxidase (POD) enzymes were boosted by all of the tested concentrations of H2O2. The relative transcript abundance of selected regulatory genes was also investigated. Except for the highest dose (80 µM), the tested concentrations had almost inhibitory effect on the relative transcripts of heat shock protein (HSP90), glutamate synthase (GOGAT), delta-9 desaturase (desC), iron-superoxide dismutase (FeSOD) and the Rubisco (the large subunit, rbcL) genes. The results demonstrated the importance of the non-enzymatic and enzymatic antioxidants for the cumulative tolerance of A. platensis.

Chromatographic Analyses of Spirulina (Arthrospira platensis) and Mechanism of Its Protective Effects against Experimental Obesity and Hepatic Steatosis in Rats.

Background and Objectives: Obesity is currently a major health problem due to fatty acid accumulation and excess intake of energy, which leads to an increase in oxidative stress, particularly in the liver. The main goal of this study is to evaluate the protective effects of spirulina (SP) against cafeteria diet (CD)-induced obesity, oxidative stress, and lipotoxicity in rats. Materials and Methods: The rats were divided into four groups and received daily treatments for eight weeks as follows: control group fed a standard diet (SD 360 g/d); cafeteria diet group (CD 360 g/d); spirulina group (SP 500 mg/kg); and CD + SP group (500 mg/kg, b.w., p.o.) according to body weight (b.w.) per oral (p.o.). Results: Our results show that treatment with a CD increased the weights of the body, liver, and abdominal fat. Additionally, severe hepatic alteration, disturbances in the metabolic parameters of serum, and lipotoxicity associated with oxidative stress in response to the CD-induced obesity were observed. However, SP treatment significantly reduced the liver alteration of CD feed and lipid profile disorder associated with obesity. Conclusions: Our findings suggest that spirulina has a marked potential therapeutic effect against obesity and mitigates disturbances in liver function parameters, histological alterations, and oxidative stress status.

Phycocyanin as a nature-inspired antidiabetic agent: A systematic review.

BACKGROUND: Nutraceuticals have been important for more than two decades for their safety, efficacy, and outstanding effects. Diabetes is a major metabolic syndrome, which may be improved using nutritional pharmaceuticals. Some microalgae species, such as spirulina, stand out by providing biomass with exceptional nutritional properties. Spirulina has a wide range of pharmacological effects, mostly related to phycocyanin. Phycocyanin is a protein compound with antidiabetic properties, known as a nutraceutical. OBJECTIVE: This review delves into phycocyanin applications in diabetes and its complications and ascertains the mechanisms involved. METHODS: Scopus, PubMed, Cochrane Library, Web of Science, and ProQuest databases were systematically reviewed (up to April 30, 2023), in which only animal and cellular studies were found. RESULTS: According to animal studies, the administration of phycocyanin affected biochemical parameters (primary outcome) related to diabetes. These results showed an increase in fasting insulin serum and a decrease in fasting blood glucose, glycosylated serum protein, and glycosylated hemoglobin. In cellular studies, though, phycocyanin prevented methylglyoxal and human islet amyloid polypeptide-induced dysfunction in ß-cells and induced apoptosis through different molecular pathways (secondary outcome), including activation of Nrf2, PI3K/Akt, and suppression of JNK and p38. Also, phycocyanin exerted its antidiabetic effect by affecting the pathways regulating hepatic glucose metabolism. CONCLUSIONS: Thus, based on the available information and literature, targeting these pathways by phycocyanin may unleash an array of benefits, including positive outcomes of the antidiabetic effects of phycocyanin as a nutraceutical. OTHER: This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) at the National Institute of Health. The registration number is CRD42022307522.

Screening of Spirulina Components for Anti-Parkinson's and Anti-Alzheimer's Activity by in Silico Methods and Docking Studies.

Spirulina platensis was first isolated from Lake Texcoco by Aztecs in the sixteenth century. In 2012, spirulina was considered to be safe dietary supplement by the Food and Drug Administration (FDA). Spirulina is a cyanophytic microalgae that is often considered as single cell protein. It contains many essential amino acids, proteins, fatty acids, antioxidant pigments, carotenoids, and cyanogenic pigments, that is, phycocyanobilins and phycocyanins (Eriksen, Appl Microbiol Biotechnol, 80(1):1-4, 2008). Components of spirulina are investigated for many health benefits and for pharmaceutical uses (Karkos et al., Spirulina in clinical practice: evidence-based human applications). Spirulina has been found to have a role in growth, immunity (Wu et al., Arch Toxicol, 90(8):1817-40, 2016), antioxidant (Wu et al., Arch Toxicol, 90(8):1817-40, 2016), antiviral (Ayehunie et al., J Acquir Immune Defic Syndr Hum Retrovirol, 18(1):7-12, 1998), antitoxicologic, anti-cancerogenic (Hirahashi et al., Int Immunopharmacol, 2(4):423-34, 2002), antidiabetic (Layam and Reddy, Diabetol Croat, 35(2):29-33, 2006), and neuroprotective properties. In this study, we focused on spirulina components in anti-Parkinson's and anti-Alzheimer's activity. Four potential targets, two for each activity, that is, structure of parkinE3 ligase (PDB ID:4I1H) and structure of BACE bound to 5-(3-(5-chloropyridin-3-yl)phenyl)-5-cyclopropyl-2-imino-3-methylimidazolidin-4one (PDBI D:4DJx) for anti-Parkinson's activity and structure of human MAO B in complex with selective inhibitor safinamide (PDB ID:2V5Z) and crystal structure of human BACE-1 in complex with CNP520(PDB ID:6EQM) for anti-Alzheimer's activity, have been selected. The in silico results and scoring of virtual screening, that is, molecular docking, were compared with commonly used marketed drugs such as levodopa for Parkinson's disease (PD) and rivastigmine (Rösler et al., BMJ, 318(7184):633-40, 1999) for Alzheimer's disease.