Carotenoids from Cyanobacteria: A Biotechnological Approach for the Topical Treatment of Psoriasis

The bioactivities and biotechnological production approaches of carotenoids derived from microalgae and cyanobacteria

Microalgae and cyanobacteria are a rich source of carotenoids that are well known for their potent bioactivities, including antioxidant, anti-cancer, anti-proliferative, anti-inflammatory, and anti-obesity properties. Recently, many interests have also been focused on the biological activities of these microalgae/cyanobacteria-derived carotenoids, such as fucoxanthin and β-carotene potential to be the salutary nutraceuticals, on treating or preventing human common diseases (e.g., cancers). This is due to their special chemical structures that demonstrate unique bioactive functions, in which the biologically active discrepancies might attribute to the different spatial configurations of their molecules. In addition, their abundance and bioaccessibilities make them more popularly applied in food and pharmaceutical industries, as compared to the macroalgal/fungal-derived ones. This review is focused on the recent studies on the bioactivities of fucoxanthin and some carotenoids derived from microalgae and cyanobacteria in relationship with human health and diseases, with emphasis on their potential applications as natural antioxidants. Various biotechnological approaches employed to induce the production of these specific carotenoids from the culture of microalgae/cyanobacteria are also critically reviewed. These well-developed and emerging biotechnologies present promise to be applied in food and pharmaceutical industries to facilitate the efficient manufacture of the bioactive carotenoid products derived from microalgae and cyanobacteria.

LC-ESI-UHR-QqTOF-MS/MS profiling and anti-inflammatory potential of the cultivated Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. fruits from the Algerian region

Opuntia plants are abundant but still underexplored edible resources of the Algerian region. This work chemically characterizes extracts of different parts of the fruit of the commercial Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. growing in Bejaia, and evaluates their anti-inflammatory potential through different cell and cell-free bioassays. The LC-ESI-UHR-QqTOF-MS/MS analysis enabled the identification of 18 compounds, with azelaic acid and 1-O-vanilloyl-β-d-glucose reported here for the first time. Aqueous extracts of seeds were the most effective in scavenging superoxide anion radical (IC50 = 111.08 μg/mL) and presented the best anti-inflammatory potential in LPS-stimulated macrophages (IC50 = 206.30 μg/mL). The pulp of O. stricta suggested potential for addressing post-inflammatory hyperpigmentation, with piscidic and eucomic acids predicted with the strongest binding affinity towards tyrosinase, exhibiting higher scoring values than the reference inhibitor kojic acid. This pioneer study brings valuable perspectives for the pharmacological, nutritional and economic valorization of the wild O. stricta for functional foods.

Anti-inflammatory, cytotoxic and morphological impact of phycocyanin on ultraviolet radiation irradiated human fibroblast cells

BACKGROUND

Recently, the use of natural products as skin photoprotective agents has been in increasing demand. This study investigated the bioactivity of phycocyanin (PC) extracted from Spirulina sp. on human skin fibroblast cell line (CCD-966SK), specifically focusing on apoptosis, necrosis, anti-inflammatory effects, and enzymatic reactions.

METHODS

The first step of this study was cyanobacterial cell culture and the extraction and purification of PC. After that, CCD-966SK cell line was cultivated under normal and UV irradiation. The bioassays included the cytotoxicity measurement, cell viability assay, morphology determination, tumour necrosis factor-α and Interleukin 6 release assays, enzyme activity for superoxide dismutase and glutathione peroxidase as well as malondialdehyde content and the cell-free extract of cyanobacterial stains were assessed.

RESULTS

The cell viability results showed that as the concentration of the PC increased, the viability of CCD-966SK cell line was reduced, which suggested that the effect of PC on the growth of fibroblast cells was dose dependent. The morphological results indicated that presence of PC in the fibroblast cell culture medium led to a transformation in cell morphology from spindle-shaped to spherical. PC released anti-inflammatory IL-6 and TNF-a cytokines, indicating high inflammation resistance. Furthermore, the findings revealed that PC dramatically reduced the release of superoxide dismutase, glutathione peroxidase, and malondialdehyde from inflammatory cells, with the reduction being more apparent at increasing doses.

CONCLUSIONS

In conclusion, the results indicated that PC inhibit the CCD-966SK cell line by membrane destructor, which led to the increase the leakage of cell constituent and increase enzymes activities.

Nannochloropsis oceanica Lipid Extract Moderates UVB-Irradiated Psoriatic Keratinocytes: Impact on Protein Expression and Protein Adducts

Psoriasis is characterized by excessive exfoliation of the epidermal layer due to enhanced pro-inflammatory signaling and hyperproliferation of keratinocytes, further modulated by UV-based anti-psoriatic treatments. Consequently, this study aimed to evaluate the impact of a lipid extract derived from the microalgae Nannochloropsis oceanica on the proteomic alterations induced by lipid derivatives in non-irradiated and UVB-irradiated keratinocytes from psoriatic skin lesions compared to keratinocytes from healthy individuals. The findings revealed that the microalgae extract diminished the viability of psoriatic keratinocytes without affecting the viability of these cells following UVB exposure. Notably, the microalgae extract led to an increased level of 4-HNE-protein adducts in non-irradiated cells and a reduction in 4-hydroxynonenal (4-HNE)-protein and 15-deoxy-12,14-prostaglandin J2 (15d-PGJ2)-protein adducts in UVB-exposed keratinocytes from psoriasis patients. In healthy skin cells, the extract decreased the UV-induced elevation of 4-HNE-protein and 15d-PGJ2-protein adducts. The antioxidant/anti-inflammatory attributes of the lipid extract from the Nannochloropsis oceanica suggest its potential as a protective agent for keratinocytes in healthy skin against UVB radiation's detrimental effects. Moreover, it could offer therapeutic benefits to skin cells afflicted with psoriatic lesions by mitigating their proliferation and inflammatory responses during UV radiation treatment.

Biomedical engineering utilizing living photosynthetic cyanobacteria and microalgae: Current status and future prospects

Cyanobacteria are the only prokaryotes capable of performing oxygenic photosynthesis on Earth. Besides their traditional roles serving as primary producers, cyanobacteria also synthesize abundant secondary metabolites including carotenoids, alkaloids, peptides, which have been reported to possess medicinal potentials. More importantly, the advancement of synthetic biology technology has further expanded their potential biomedical applications especially using living/engineered cyanobacteria, providing promising and attractive strategies for future disease treatments. To improve the understanding and to facilitate future applications, this review aims to discuss the current status and future prospects of cyanobacterial-based biomedical engineering. Firstly, specific properties of cyanobacteria related with biomedical applications like their natural products of bioactive compounds and heavy metal adsorption were concluded. Subsequently, based on these properties of cyanobacteria, we discussed the progress of their applications in various disease models like hypoxia microenvironment alleviation, wound healing, drug delivery, and so on. Finally, the future prospects including further exploration of cyanobacteria secondary metabolites, the integration of bioactive compounds synthesized by cyanobacteria in situ with medical diagnosis and treatment, and the optimization of in vivo application were critically presented. The review will promote the studies related with cyanobacteria-based biomedical engineering and its practical application in clinical trials in the future.

Nutraceutical prospects of genetically engineered cyanobacteria- technological updates and significance

Genetically engineered cyanobacterial strains that have improved growth rate, biomass productivity, and metabolite productivity could be a better option for sustainable bio-metabolite production. The global demand for biobased metabolites with nutraceuticals and health benefits has increased due to their safety and plausible therapeutic and nutritional utility. Cyanobacteria are solar-powered green cellular factories that can be genetically tuned to produce metabolites with nutraceutical and pharmaceutical benefits. The present review discusses biotechnological endeavors for producing bioprospective compounds from genetically engineered cyanobacteria and discusses the challenges and troubleshooting faced during metabolite production. This review explores the cyanobacterial versatility, the use of engineered strains, and the techno-economic challenges associated with scaling up metabolite production from cyanobacteria. Challenges to produce cyanobacterial bioactive compounds with remarkable nutraceutical values have been discussed. Additionally, this review also summarises the challenges and future prospects of metabolite production from genetically engineered cyanobacteria as a sustainable approach.

Cyanobacterial bloom-associated lipopolysaccharides induce pro-inflammatory processes in keratinocytes in vitro

Our previous studies have shown that CyanoHAB LPS (lipopolysaccharides) and LPS from cyanobacterial cultures induce pro-inflammatory effects on intestinal epithelial and immune cells in vitro. To expand our understanding, we investigated their impact on human keratinocytes, which are targeted during water recreational activities. LPS samples were isolated from CyanoHAB biomasses dominated by Microcystis, Aphanizomenon, Planktothrix, and Dolichospermum, or from axenic cultures of these genera. We identified two CyanoHAB biomasses containing a high proportion of Gram-negative bacteria, including potentially pathogenic genera. These biomasses showed the highest induction of interleukin (IL) 8, IL-6, C-C motif chemokine ligand (CCL) 2 (also known as MCP-1), and CCL20 production by HaCaT cells. Interestingly, all CyanoHAB-derived LPS and LPS from axenic cultures (except for Microcystis) accelerated cell proliferation and migration. Our findings highlight the role of G- bacteria composition and LPS structural disparities in influencing these effects, with implications for skin health during recreational activities.

Altered structure indicating reduced barrier function of lesional compared to non-lesional psoriatic skin-A non-invasive in vivo study of the human stratum corneum with confocal Raman micro-spectroscopy

Psoriasis, one of the most common skin diseases affecting roughly 2%-3% of the world population, is associated with a reduced skin barrier function (SBF) that might play an important role in its pathophysiology. The SBF is provided primarily by the stratum corneum (SC) of the skin. Previous studies have revealed a higher trans-epidermal water loss, lower hydration, abnormal concentration and composition of intercellular lipids, as well as alterations in secondary keratin structure in the psoriatic SC. We compared on molecular level lesional psoriatic skin (LPS) with non-lesional psoriatic skin (nLPS) from 19 patients non-invasively in vivo, using confocal Raman micro-spectroscopy. By analysing the corresponding Raman spectra, we determined SBF-defining parameters of the SC depth-dependently. Our results revealed a lower total lipid concentration, a shift of lamellar lipid organisation towards more gauche-conformers and an increase of the less dense hexagonal lateral packing of the intercellular lipids in LPS. Furthermore, we observed lower natural moisturising factor concentration, lower total water as well as a strong tendency towards less strongly bound and more weakly bound water molecules in LPS. Finally, we detected a less stable secondary keratin structure with increased β-sheets, in contrast to the tertiary structure, showing a higher degree of folded keratin in LPS. These findings clearly suggest structural differences indicating a reduced SBF in LPS, and are discussed in juxtaposition to preceding outcomes for psoriatic and healthy skin. Understanding the alterations of the psoriatic SC provides insights into the exact pathophysiology of psoriasis and paves the way for optimal future treatments.

Recent Reports on Bioactive Compounds from Marine Cyanobacteria in Relation to Human Health Applications

The ocean is a valuable natural resource that contains numerous biologically active compounds with various bioactivities. The marine environment comprises unexplored sources that can be utilized to isolate novel compounds with bioactive properties. Marine cyanobacteria are an excellent source of bioactive compounds that have applications in human health, biofuel, cosmetics, and bioremediation. These cyanobacteria exhibit bioactive properties such as anti-inflammatory, anti-cancer, anti-bacterial, anti-parasitic, anti-diabetic, anti-viral, antioxidant, anti-aging, and anti-obesity effects, making them promising candidates for drug development. In recent decades, researchers have focused on isolating novel bioactive compounds from different marine cyanobacteria species for the development of therapeutics for various diseases that affect human health. This review provides an update on recent studies that explore the bioactive properties of marine cyanobacteria, with a particular focus on their potential use in human health applications.

Microalgae, Seaweeds and Aquatic Bacteria, Archaea, and Yeasts: Sources of Carotenoids with Potential Antioxidant and Anti-Inflammatory Health-Promoting Actions in the Sustainability Era

Carotenoids are a large group of health-promoting compounds used in many industrial sectors, such as foods, feeds, pharmaceuticals, cosmetics, nutraceuticals, and colorants. Considering the global population growth and environmental challenges, it is essential to find new sustainable sources of carotenoids beyond those obtained from agriculture. This review focuses on the potential use of marine archaea, bacteria, algae, and yeast as biological factories of carotenoids. A wide variety of carotenoids, including novel ones, were identified in these organisms. The role of carotenoids in marine organisms and their potential health-promoting actions have also been discussed. Marine organisms have a great capacity to synthesize a wide variety of carotenoids, which can be obtained in a renewable manner without depleting natural resources. Thus, it is concluded that they represent a key sustainable source of carotenoids that could help Europe achieve its Green Deal and Recovery Plan. Additionally, the lack of standards, clinical studies, and toxicity analysis reduces the use of marine organisms as sources of traditional and novel carotenoids. Therefore, further research on the processing of marine organisms, the biosynthetic pathways, extraction procedures, and examination of their content is needed to increase carotenoid productivity, document their safety, and decrease costs for their industrial implementation.

Overexpressing Carotenoid Biosynthetic Genes in Synechocystis sp. PCC 6803 Improved Intracellular Pigments and Antioxidant Activity, Which Can Decrease the Viability and Proliferation of Lung Cancer Cells In Vitro

In the antioxidant system in cyanobacteria, non-enzymatic antioxidants, such as carotenoids, are considered good candidates for coping with oxidative stress, particularly light stress, and pharmaceutical therapeutic applications. A significant amount of carotenoid accumulation has been recently improved by genetic engineering. In this study, to achieve higher carotenoid production with higher antioxidant activity, we successfully constructed five Synechocystis sp. PCC 6803 strains overexpressing (OX) native genes related to the carotenoids biosynthetic pathway, including OX_CrtB, OX_CrtP, OX_CrtQ, OX_CrtO, and OX_CrtR. All of the engineered strains maintained a significant quantity of myxoxanthophyll, while increasing zeaxanthin and echinenone accumulation. In addition, higher components of zeaxanthin and echinenone were noted in all OX strains, ranging from 14 to 19% and from 17 to 22%, respectively. It is worth noting that the enhanced echinenone component responded to low light conditions, while the increased β-carotene component contributed to a high light stress response. According to the higher antioxidant activity of all OX strains, the carotenoid extracts presented lower IC₅₀ in lung cancer cell lines H460 and A549, with values less than 157 and 139 µg/mL, respectively, when compared with those of WTc, particularly OX_CrtR and OX_CrtQ. A higher proportion of zeaxanthin and β-carotene in OX_CrtR and OX_CrtQ, respectively, may considerably contribute to the ability to treat lung cancer cells with antiproliferative and cytotoxic effects.

Antioxidant, Anti-Inflammatory and Anti-Obesity Potential of Extracts Containing Phenols, Chlorophyll and Carotenoids from Mexican Wild Populations of Bacopa monnieri (L.) Wettst

Some of the species of the genus Bacopa have been used in Pharmacopoeia worldwide. However, in Mexico, Bacopa monnieri has neither been extensively cultivated nor studied, nor has their use in traditional medicine been reported. The aim of this work was to assess the taxonomic verification of the four wild populations of B. monnieri, the chemical content of their pigments and phenols and to provide an analysis of their potential bioactivity. B. monnieri wild populations from Mexico were validated using molecular markers. Chromatographic profiling using HPLC-PDA revealed 21 compounds comprising 12 chlorophylls and nine carotenoids; of the latter, the major ones were lutein (0.921 ± 0.031 μg/mg of dry extract) and β-carotene (0.095 ± 0.003 μg/mg of dry extract). The total phenolic content, determined using the Folin-Ciocalteu assay, ranged from 54.8 ± 5.8 to 70.3 ± 2.2 µg of gallic acid equivalents (GAE)/mg. Plant extracts scavenged from the free radical DPPH in IC₅₀ ranged from 130.6 ± 3.0 to 249.9 ± 12.1 µg dry extract/mL. In terms of the anti-inflammatory potential, the most effective extract was from a soil-based plant from Jalisco (BS), reduced from nitric oxide in a RAW 264.7 culture medium, with an IC₅₀ value of 134 µg of dry extract/mL. The BS extract showed a significant neutral lipid-reducing activity in the zebrafish model, ranging from 3.13 μg/mL p < 0.05 to 100 μg/mL p < 0.0001. Overall, the extracts analyzed here for the first time seem promising for future use because of their antioxidant, anti-inflammatory and anti-obesity potential.

Evaluation of the effects of Lake Hévíz sulfur thermal water on skin microbiome in plaque psoriasis: An open label, pilot study

Psoriasis is a chronic inflammatory skin disease. It is associated with changes in skin microbiome. The aim of this study was to evaluate how Lake Hévíz sulfur thermal water influences the composition of microbial communities that colonizes skin in patients with psoriasis. Our secondary objective was to investigate the effects of balneotherapy on disease activity. In this open label study, participants with plaque psoriasis underwent 30-min therapy sessions in Lake Hévíz, at a temperature of 36 °C, five times a week for 3 weeks. The skin microbiome samples were collected by swabbing method from two different areas (lesional skin-psoriatic plaque and non-lesional skin). From 16 patients, 64 samples were processed for a 16S rRNA sequence-based microbiome analysis. Outcome measures were alpha-diversity (Shannon, Simpson, and Chao1 indexes), beta-diversity (Bray-Curtis metric), differences in genus level abundances, and Psoriasis Area and Severity Index (PASI). Skin microbiome samples were collected at baseline, and immediately after treatment. Based on the visual examination of the employed alpha- and beta-diversity measures, no systematic difference based on sampling timepoint or sample location could be revealed in these regards. Balneotherapy in the unaffected area significantly increased the level of Leptolyngbya genus, and significantly decreased the level of Flavobacterium genus. A similar trend was revealed by the results of the psoriasis samples, but the differences were not statistically significant. In patients with mild psoriasis, a significant improvement was observed in PASI scores.

A Multiplex Molecular Cell-Based Sensor to Detect Ligands of PPARs: An Optimized Tool for Drug Discovery in Cyanobacteria

Cyanobacteria produce a wealth of secondary metabolites. Since these organisms attach fatty acids into molecules in unprecedented ways, cyanobacteria can serve as a novel source for bioactive compounds acting as ligands for Peroxisome Proliferator-Activated Receptors (PPAR). PPARs (PPARα, PPARβ/δ and PPARγ) are ligand-activated nuclear receptors, involved in the regulation of various metabolic and cellular processes, thus serving as potential drug targets for a variety of pathologies. Yet, given that PPARs' agonists can have pan-, dual- or isoform-specific action, some controversy has been raised over currently approved drugs and their side effects, highlighting the need for novel molecules. Here, we expand and validate a cell-based PPAR transactivation activity biosensor, and test it in a screening campaign to guide drug discovery. Biosensor upgrades included the use of different reporter genes to increase signal intensity and stability, a different promoter to modulate reporter gene expression, and multiplexing to improve efficiency. Sensor's limit of detection (LOD) ranged from 0.36-0.89 nM in uniplex and 0.89-1.35 nM in multiplex mode. In triplex mode, the sensor's feature screening, a total of 848 fractions of 96 cyanobacteria extracts were screened. Hits were confirmed in multiplex mode and in uniplex mode, yielding one strain detected to have action on PPARα and three strains to have dual action on PPARα and -β.

Sustainable Production of Pigments from Cyanobacteria

Pigments are intensely coloured compounds used in many industries to colour other materials. The demand for naturally synthesised pigments is increasing and their production can be incorporated into circular bioeconomy approaches. Natural pigments are produced by bacteria, cyanobacteria, microalgae, macroalgae, plants and animals. There is a huge unexplored biodiversity of prokaryotic cyanobacteria which are microscopic phototrophic microorganisms that have the ability to capture solar energy and CO2 and use it to synthesise a diverse range of sugars, lipids, amino acids and biochemicals including pigments. This makes them attractive for the sustainable production of a wide range of high-value products including industrial chemicals, pharmaceuticals, nutraceuticals and animal-feed supplements. The advantages of cyanobacteria production platforms include comparatively high growth rates, their ability to use freshwater, seawater or brackish water and the ability to cultivate them on non-arable land. The pigments derived from cyanobacteria and microalgae include chlorophylls, carotenoids and phycobiliproteins that have useful properties for advanced technical and commercial products. Development and optimisation of strain-specific pigment-based cultivation strategies support the development of economically feasible pigment biorefinery scenarios with enhanced pigment yields, quality and price. Thus, this chapter discusses the origin, properties, strain selection, production techniques and market opportunities of cyanobacterial pigments.

Cosmetic Application of Cyanobacteria Extracts with a Sustainable Vision to Skincare: Role in the Antioxidant and Antiaging Process

Nature-based and sustainably sourced cosmetics have been dominating the area of skincare products worldwide. Due to their antioxidant and antiaging properties, compounds from cyanobacteria, such as carotenoids and phycobiliproteins, may replace synthetic ingredients in cosmetic formulations and may be used in products such as sunscreens, skincare creams, and makeup. In this study, we evaluated the potential of acetonic and aqueous extracts from cyanobacteria strains of the genera Cyanobium and Leptothoe and from strains within Synechococcales and Oscillatoriales orders, for use in cosmetics. Extractions were sequentially performed with acetone and water. Extracts were firstly analyzed for their toxicity to keratinocytes, fibroblasts, and endothelial cells (HaCAT, 3T3L1 and hCMEC/D3, respectively). The non-cytotoxic extracts were characterized in terms of total proteins, carotenoids, chlorophyll, phenols, phycobiliproteins, and analyzed for their antioxidant potential against the superoxide anion radical (O2•−), and for their ability to inhibit key enzymes associated with the skin aging process. Aqueous extracts were richer in total proteins and phycobiliproteins. The aqueous extracts of Synechococcales cyanobacterium LEGE 181157 and Synechococcales cyanobacterium LEGE 181150 showed the highest value for total proteins (760.81 and 695.25 μg BSA mL−1dry extract, respectively) and the best values regarding O2•− scavenging (IC50 = 63.24 and 112.18 μg mL−1dry extract, respectively) with a significant negative correlation observed (p < 0.01). Moreover, aqueous extracts of Synechococcales cyanobacterium LEGE 181150 and Synechococcales cyanobacterium LEGE 181157 inhibited hyaluronidase, (IC50 of 483.86 and 645.06 μg mL−1dry extract, respectively), with a significant negative correlation with total proteins (p < 0.05), pointing out the contribution of these compounds to the biological activities observed. Acetonic extracts were richer in carotenoids and phenols. Zeaxanthin and β-carotene were predominant among all strains, being present in higher amount in Cyanobium sp. LEGE 07175 (53.08 μg mg−1) and Leptothoe sp. LEGE 181156 (47.89 μg mg−1), respectively. The same strains also showed the highest values for collagenase inhibition at 750 μg mL−1dry extract (32.88 and 36.61%, respectively). Furthermore, Leptothoe sp. LEGE 181156 exhibited the lowest IC50 value for tyrosinase inhibition (465.92 μg mL−1dry extract) and Synechococcales cyanobacterium LEGE 181157 presented the best values for elastase inhibition (IC50 of 380.50 and IC25 of 51.43 μg mL−1dry extract). In general, cyanobacteria extracts demonstrated potential for being used for antiaging purposes, with aqueous extracts being more efficient at free radicals scavenging and acetonic ones at avoiding degradation of dermal matrix components.

Versatile Applications of Cyanobacteria in Biotechnology

Cyanobacteria are blue-green Gram-negative and photosynthetic bacteria which are seen as one of the most morphologically numerous groups of prokaryotes. Because of their ability to fix gaseous nitrogen and carbon dioxide to organic materials, they are known to play important roles in the universal nutrient cycle. Cyanobacteria has emerged as one of the promising resources to combat the issues of global warming, disease outbreaks, nutrition insecurity, energy crises as well as persistent daily human population increases. Cyanobacteria possess significant levels of macro and micronutrient substances which facilitate the versatile popularity to be utilized as human food and protein supplements in many countries such as Asia. Cyanobacteria has been employed as a complementary dietary constituent of feed for poultry and as vitamin and protein supplement in aquatic lives. They are effectively used to deal with numerous tasks in various fields of biotechnology, such as agricultural (including aquaculture), industrial (food and dairy products), environmental (pollution control), biofuel (bioenergy) and pharmaceutical biotechnology (such as antimicrobial, anti-inflammatory, immunosuppressant, anticoagulant and antitumor); recently, the growing interest of applying them as biocatalysts has been observed as well. Cyanobacteria are known to generate a numerous variety of bioactive compounds. However, the versatile potential applications of cyanobacteria in biotechnology could be their significant growth rate and survival in severe environmental conditions due to their distinct and unique metabolic pathways as well as active defensive mechanisms. In this review, we elaborated on the versatile cyanobacteria applications in different areas of biotechnology. We also emphasized the factors that could impede the implementation to cyanobacteria applications in biotechnology and the execution of strategies to enhance their effective applications.

Targeting deregulated oxidative stress in skin inflammatory diseases: An update on clinical importance

Skin, the largest vital organ of the human body, provides the first line of defense against biological, non-biological and xenobiotics exposure. Over the years, due to increased anthropogenic activities including industrialization and pollution, a steep increase in cutaneous pathological conditions such as malignancies, dermatitis, and psoriasis has been detected. Indeed, due to the complex nature of cutaneous inflammatory diseases, further investigations are required to produce a better outcome in patient care. However, research obtained over the last few decades has revolutionized the understanding of cutaneous disease pathogenesis and therapeutic developments. In this line, increasing data from pre-clinical and clinical studies implicates the crucial role of oxidative stress in pathogenesis and complications of cutaneous inflammatory diseases, including atopic dermatitis and psoriasis. Taking into consideration the current challenge, this review aims to highlight the novel updates exploring reactive oxygen species (ROS) induced mechanistic signaling mechanisms in conjunction with pathways converging towards atopic dermatitis and psoriasis. Additionally, an exploration of the clinical importance of natural products for management of cutaneous diseases has been included. Overall, this review highlights the therapeutic importance of targeting oxidative stress in the pathogenesis, symptoms, and complications of inflammatory diseases of the skin.

Natural Substrates and Culture Conditions to Produce Pigments from Potential Microbes in Submerged Fermentation

Pigments from bacteria, fungi, yeast, cyanobacteria, and microalgae have been gaining more demand in the food, leather, and textile industries due to their natural origin and effective bioactive functions. Mass production of microbial pigments using inexpensive and ecofriendly agro-industrial residues is gaining more demand in the current research due to their low cost, natural origin, waste utilization, and high pigment stimulating characteristics. A wide range of natural substrates has been employed in submerged fermentation as carbon and nitrogen sources to enhance the pigment production from these microorganisms to obtain the required quantity of pigments. Submerged fermentation is proven to yield more pigment when added with agro-waste residues. Hence, in this review, aspects of potential pigmented microbes such as diversity, natural substrates that stimulate more pigment production from bacteria, fungi, yeast, and a few microalgae under submerged culture conditions, pigment identification, and ecological functions are detailed for the benefit of industrial personnel, researchers, and other entrepreneurs to explore pigmented microbes for multifaceted applications. In addition, some important aspects of microbial pigments are covered herein to disseminate the knowledge.

A biochemical, physiological and molecular evaluation of how the herbicide 2, 4-dichlorophenoxyacetic acid intercedes photosynthesis and diazotrophy in the cyanobacterium Nostoc muscorum Meg 1

Among the non-target microorganisms residing in crop fields that are potentially vulnerable to herbicides are cyanobacteria. They contribute to the maintenance of soil quality and fertility and hence are considered to be an important component of soil microflora. Consequently, the present study was aimed to check the influence of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on some major parameters of carbon (CO₂) and nitrogen (N₂) fixations of a cyanobacterium Nostoc muscorum Meg 1 isolated from a rice field in Cherrapunji, Meghalaya, India. These include various photosynthetic pigments, the oxygen-evolving complex activity of the PSII, the protein contents of RuBisCO, D1 protein, isocitrate dehydrogenase (IDH), nitrogenase and glutamine synthetase (GS) enzymes, the heterocyst percentage, nitrogenase and GS enzyme activities, and production of total proteins and carbohydrates in the cyanobacterium in a varying range of 50 to 125 ppm doses of 2,4-D. The mRNA levels of several proteins were also analyzed. Besides carotenoid concentration that enhanced at 50 ppm, all other parameters were compromised by 2,4-D in a dose-dependent manner resulting in a reduction in photosynthetic and N₂-fixing activities. The negative effect on N₂-fixation was partly due to compromised IDH activity. RT-PCR analysis further showed that these negative effects were initiated at transcription levels as mRNA contents of all enzymes studied were found compromised under 2,4-D exposure. The scanning and transmission electron microscopy further revealed herbicide induced adverse changes in the morphology and ultrastructure of the organism. The significance of the work lies in its detailed analysis of the effect of 2,4-D at biochemical, physiological, and molecular levels.

Cyanobacterial secondary metabolites towards improved commercial significance through multiomics approaches

Cyanobacteria are ubiquitous photosynthetic prokaryotes responsible for the oxygenation of the earth's reducing atmosphere. Apart from oxygen they are producers of a myriad of bioactive metabolites with diverse complex chemical structures and robust biological activities. These secondary metabolites are known to have a variety of medicinal and therapeutic applications ranging from anti-microbial, anti-viral, anti-inflammatory, anti-cancer, and immunomodulating properties. The present review discusses various aspects of secondary metabolites viz. biosynthesis, types and applications, which highlights the repertoire of bioactive constituents they harbor. Majority of these products have been produced from only a handful of genera. Moreover, with the onset of various OMICS approaches, cyanobacteria have become an attractive chassis for improved secondary metabolites production. Also the intervention of synthetic biology tools such as gene editing technologies and a variety of metabolomics and fluxomics approaches, used for engineering cyanobacteria, have significantly enhanced the production of secondary metabolites.

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation, Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.

Potential Anti-Obesity, Anti-Steatosis, and Anti-Inflammatory Properties of Extracts from the Microalgae Chlorella vulgaris and Chlorococcum amblystomatis under Different Growth Conditions

Microalgae are known as a producer of proteins and lipids, but also of valuable compounds for human health benefits (e.g., polyunsaturated fatty acids (PUFAs); minerals, vitamins, or other compounds). The overall objective of this research was to prospect novel products, such as nutraceuticals from microalgae, for application in human health, particularly for metabolic diseases. Chlorella vulgaris and Chlorococcum amblystomatis were grown autotrophically, and C. vulgaris was additionally grown heterotrophically. Microalgae biomass was extracted using organic solvents (dichloromethane, ethanol, ethanol with ultrasound-assisted extraction). Those extracts were evaluated for their bioactivities, toxicity, and metabolite profile. Some of the extracts reduced the neutral lipid content using the zebrafish larvae fat metabolism assay, reduced lipid accumulation in fatty-acid-overloaded HepG2 liver cells, or decreased the LPS-induced inflammation reaction in RAW264.7 macrophages. Toxicity was not observed in the MTT assay in vitro or by the appearance of lethality or malformations in zebrafish larvae in vivo. Differences in metabolite profiles of microalgae extracts obtained by UPLC-LC-MS/MS and GNPS analyses revealed unique compounds in the active extracts, whose majority did not have a match in mass spectrometry databases and could be potentially novel compounds. In conclusion, microalgae extracts demonstrated anti-obesity, anti-steatosis, and anti-inflammatory activities and could be valuable resources for developing future nutraceuticals. In particular, the ultrasound-assisted ethanolic extract of the heterotrophic C. vulgaris significantly enhanced the anti-obesity activity and demonstrated that the alteration of culture conditions is a valuable approach to increase the production of high-value compounds.

Bioactive Metabolites Produced by Cyanobacteria for Growth Adaptation and Their Pharmacological Properties

Cyanobacteria are the most abundant oxygenic photosynthetic organisms inhabiting various ecosystems on earth. As with all other photosynthetic organisms, cyanobacteria release oxygen as a byproduct during photosynthesis. In fact, some cyanobacterial species are involved in the global nitrogen cycles by fixing atmospheric nitrogen. Environmental factors influence the dynamic, physiological characteristics, and metabolic profiles of cyanobacteria, which results in their great adaptation ability to survive in diverse ecosystems. The evolution of these primitive bacteria resulted from the unique settings of photosynthetic machineries and the production of bioactive compounds. Specifically, bioactive compounds play roles as regulators to provide protection against extrinsic factors and act as intracellular signaling molecules to promote colonization. In addition to the roles of bioactive metabolites as indole alkaloids, terpenoids, mycosporine-like amino acids, non-ribosomal peptides, polyketides, ribosomal peptides, phenolic acid, flavonoids, vitamins, and antimetabolites for cyanobacterial survival in numerous habitats, which is the focus of this review, the bioactivities of these compounds for the treatment of various diseases are also discussed.

Bioactive Potential of Two Marine Picocyanobacteria Belonging to Cyanobium and Synechococcus Genera

Coccoid cyanobacteria produce a great variety of secondary metabolites, which may have useful properties, such as antibacterial, antiviral, anticoagulant or anticancer activities. These cyanobacterial metabolites have high ecological significance, and they could be considered responsible for the widespread occurrence of these microorganisms. Considering the great benefit derived from the identification of competent cyanobacteria for the extraction of bioactive compounds, two strains of picocyanobacteria (coccoid cyanobacteria < 3 µm) (Cyanobium sp. ITAC108 and Synechococcus sp. ITAC107) isolated from the Mediterranean sponge Petrosia ficiformis were analyzed. The biological effects of organic and aqueous extracts from these picocyanobacteria toward the nauplii of Artemia salina, sea urchin embryos and human cancer lines (HeLa cells) were evaluated. Methanolic and aqueous extracts from the two strains strongly inhibited larval development; on the contrary, in ethyl acetate and hexane extracts, the percentage of anomalous embryos was low. Moreover, all the extracts of the two strains inhibited HeLa cell proliferation, but methanol extracts exerted the highest activity. Gas chromatography–mass spectrometry analysis evidenced for the first time the presence of β-N-methylamino-l-alanine and microcystin in these picocyanobacteria. The strong cytotoxic activity observed for aqueous and methanolic extracts of these two cyanobacteria laid the foundation for the production of bioactive compounds of pharmacological interest.

Cyanobacteria and microalgae bioactive compounds in skin-ageing: potential to restore extracellular matrix filling and overcome hyperpigmentation

As the largest organ in human body, skin acts as a physicochemical barrier, offering protection against harmful environmental stressors, such as chemicals, pathogens, temperature and radiation. Nonetheless, skins prominence goes further, with a significant psychosocial role in an increasingly ageing population. Prompted by consumers’ concern regarding skincare, cosmetic industry has been developing new formulas capable of lessening the most visible signs of ageing, including reduction in skin density and elasticity, wrinkling and hyperpigmentation. Allied to skincare is the rising importance set on natural products, sustainably obtained from less environmental impacting methods. Cyanobacteria and microalgae are adding importance in this field, given their ability to biosynthesize secondary metabolites with anti-ageing potential. In this review, we present an overview on the potential of cyanobacteria and microalgae compounds to overcome skin-ageing, essentially by exploring their effects on the metalloproteinases collagenase, elastase, gelatinase and hyaluronidase, and in other enzymes involved in the pigmentation process.

Carotenoids from Cyanobacteria: Biotechnological Potential and Optimization Strategies

Carotenoids are tetraterpenoids molecules present in all photosynthetic organisms, responsible for better light-harvesting and energy dissipation in photosynthesis. In cyanobacteria, the biosynthetic pathway of carotenoids is well described, and apart from the more common compounds (e.g., β-carotene, zeaxanthin, and echinenone), specific carotenoids can also be found, such as myxoxanthophyll. Moreover, cyanobacteria have a protein complex called orange carotenoid protein (OCP) as a mechanism of photoprotection. Although cyanobacteria are not the organism of choice for the industrial production of carotenoids, the optimisation of their production and the evaluation of their bioactive capacity demonstrate that these organisms may indeed be a potential candidate for future pigment production in a more environmentally friendly and sustainable approach of biorefinery. Carotenoids-rich extracts are described as antioxidant, anti-inflammatory, and anti-tumoral agents and are proposed for feed and cosmetical industries. Thus, several strategies for the optimisation of a cyanobacteria-based bioprocess for the obtention of pigments were described. This review aims to give an overview of carotenoids from cyanobacteria not only in terms of their chemistry but also in terms of their biotechnological applicability and the advances and the challenges in the production of such compounds.

Epidermal carotenoid levels in vivo of patients with plaque psoriasis: Effects of narrow-band UVB phototherapy

BACKGROUND

Psoriasis is a systemic inflammatory disease characterized by hindered antioxidant defense and increased formation of free radicals. There are limited data on the skin carotenoids in psoriatic skin as well as their modulation during narrow-band UVB (NB-UVB) phototherapy of the disease.

AIM

The aim of this prospective study is to reveal the skin carotenoids levels during NB-UVB phototherapy of psoriasis in humans.

MATERIAL AND METHODS

Twenty Caucasian subjects with mild-to-moderate plaque psoriasis (15m; 5f) were enrolled in the study, and nine gender- and age-matched healthy volunteers were recruited for controls of oxidative stress measurements. All psoriasis patients underwent 10 sessions of NB-UVB phototherapy. Measurements were taken at baseline and after 10 sessions of NB-UVB phototherapy. The assessment of carotenoid levels in the skin in vivo was performed by a non-invasive, reflectance spectroscopy-based device. Psoriasis severity was assessed by psoriasis area and severity index (PASI). The dermatology life quality index (DLQI) was evaluated in psoriatic patients.

RESULTS

Baseline carotenoid levels were significantly lower in psoriasis patients in comparison to healthy controls. NB-UVB phototherapy insignificantly diminished carotenoid levels in the skin of psoriasis patients, while clinical improvement both in PASI score and DLQI was observed.

CONCLUSION

We showed the levels of skin carotenoids in psoriatic patients are lower than in healthy subjects. NB-UVB did not change significantly skin carotenoid levels. Further studies should elucidate the potential effect of antioxidants supplementation during NB-UVB of psoriasis.

Exploitation of Filamentous and Picoplanktonic Cyanobacteria for Cosmetic Applications: Potential to Improve Skin Structure and Preserve Dermal Matrix Components

The use of natural products in skin care formulations gained interest as a concern for modern societies. The undesirable side effects of synthetic compounds, as well as the associated environmental hazards, have driven investigation on photosynthetic organisms as sustainable sources of effective and environmentally friendly ingredients. The use of natural extracts in cosmetics has been highlighted and, along with plants and algae, cyanobacteria have come into focus. Due to their low culture demands, high grow rates and ability to produce a wide variability of bioactive metabolites, cyanobacteria emerged as an economic and sustainable base for the cosmetic industry. In this study, we evaluated the potential of ethanol extracts of picocyanobacteria strains of the genera Cyanobium and Synechocystis and filamentous strains of the genera Nodosilinea, Phormidium and Tychonema for skin applications, with focus in the field of anti-aging. The extracts were analyzed for their pigment profile, phenolic content, antioxidant potential, cytotoxicity against keratinocytes (HaCat), fibroblasts (3T3L1), endothelial cells (hCMEC/D3) and capacity to inhibit hyaluronidase (HAase). The total carotenoid content ranged from 118.69 to 383.89 μg g⁻¹ of dry biomass, and the total phenolic content from 1.07 to 2.45 mg GAE g⁻¹. Identified carotenoids consisted of zeaxanthin, lutein, canthaxanthin, echinenone and β-carotene, with zeaxanthin and lutein being the most representative (49.82 and 79.08 μg g⁻¹, respectively). The highest antioxidant potential was found for Phormidium sp. LEGE 05292 and Tychonema sp. LEGE 07196 for superoxide anion radical (O₂^•−) scavenging (IC₅₀ of 822.70 and 924 μg mL⁻¹, respectively). Low or no cytotoxicity were registered. Regarding HAase inhibition, Tychonema sp. LEGE 07196 and Cyanobium sp. LEGE 07175 showed the best IC₅₀ (182.74 and 208.36 μg mL⁻¹, respectively). In addition, an increase in fibroblast proliferation was registered with these same strains. From this work, the ethanol extracts of the species Tychonema sp. and Cyanobium sp. are particularly interesting for their potential application in anti-aging formulations, once they stimulated fibroblast proliferation and inhibit hyaluronic acid digestion.

Antioxidant and Cytoprotective Properties of Cyanobacteria: Potential for Biotechnological Applications

Antioxidant compounds from cyanobacteria may constitute a natural alternative to current synthetic antioxidants, which contain preservatives and suspected toxicity. In this work, we evaluate the antioxidant potential of cyanobacterial strains of distinct species/genus isolated from freshwater (n = 6), soil (n = 1) and wastewater (n = 1) environments. Lyophilized biomass obtained from in-vitro cultures of those strains was extracted with ethanol and methanol. The antioxidant potential was evaluated by chemical (DPPH scavenging method, β-carotene bleaching assay, determination of total phenolic and total flavonoid compounds) and biological (H₂O₂-exposed HEK293T cell line model) approach. Some strains showed high yields of antioxidant activity by the DPPH assay (up to 10.7% IP/20.7 TE μg/mL) and by the β-carotene bleaching assay (up to 828.94 AAC), as well as significant content in phenolic (123.16 mg EAG/g DW) and flavonoid (900.60 mg EQR/g DW) compounds. Normalization of data in a “per cell” or “per cell volume” base might facilitate the comparison between strains. Additionally, most of the cyanobacterial extracts conferred some degree of protection to HEK293T cells against the H₂O₂-induced cytotoxicity. Freshwater Aphanizomenon gracile (LMECYA 009) and Aphanizomenon flos-aquae (LMECYA 088), terrestrial Nostoc (LMECYA 291) and wastewater Planktothrix mougeotii (LEGE 06224) seem to be promising strains for further investigation on cyanobacteria antioxidant potential.