Inhibitory effects of dietary Spirulina platensis on UVB-induced skin inflammatory responses and carcinogenesis

Prospects of nano-theranostic approaches against breast and cervical cancer

The bottleneck on therapeutics and diagnostics is removed by an alternate approach known as theranostics which combines both therapeutics and diagnostics within a single platform. Due to this "all in one" nature of theranostics, it is now extensively applied in the medicinal field mainly in cancer treatment over the conventional therapy. Recently, FDA approval of lutetium 177 (177Lu) DOTATATE and 177Lu-PSMA-based radionuclide theranostics are clinically used and very few theranostics specific to breast cancer are in clinical trials. In this review, we are willing to draw special attention to the application of theranostics in the most relevant cancers in women, the breast and the cervical as these cancers affect women harshly but talked very silently due to the social restrictions and discriminations mainly in rural areas of developing and under developing countries. This approach not only combines therapeutics and diagnostics but targeting moieties can also be accommodated for the precise medication. Herein, our main objective is to enlighten the broader aspects of different kinds of theranostic devices based on radioisotopes, nanoparticles, graphene quantum dots, dendrimers and their fruitful application against breast and cervical cancer. The development of synthetic nano-theranostics was reported by accommodating therapeutic drugs, imaging probes and targeting ligands through conjugation or encapsulation. The imaging modalities like optical fluorescence, photosensitizers and radiotracers are used to get the diagnostic images through NIR, PET, MRI and CT/SPECT to detect the progress of cancer non-invasively and also at the same time targeting ligands such as antibodies, proteins and peptides in attachment with the theranostics enhances the therapeutic efficacy in addition to the clarity in diagnostics. The applications of theranostics from the last decade with their present scenario in clinics and future perspectives, as well as the pitfalls with the hurdles that still leave questions to rethink from the root are also been discussed in this review.

Amino acid HPLC-FLD analysis of spirulina and its protective mechanism against the combination of obesity and colitis in wistar rats

Objective

The cafeteria diet (CD), designed as an experimental diet mimicking the obesogenic diet, may contribute to the pathogenesis of inflammatory bowel diseases (IBD). This study delves into the influence of spirulina (SP) on obesity associated with colitis in Wistar rats.

Methods

The amino acids composition of SP was analyzed using HPLC-FLD. Animals were equally separated into eight groups, each containing seven animals and treated daily for eight weeks as follows: Control diet (SD), cafeteria diet (CD) group, CD + SP (500 mg/kg) and SD + SP. Ulcerative colitis was provoked by rectal injection of acetic acid (AA) (3 % v/v, 5 ml/kg b.w.) on the last day of treatment in the following groups: SD + AA, SD + AA + SP, CD + AA, and CD + AA + SP.

Results

Findings revealed that UC and/or CD increased the abdominal fat, weights gain, and colons. Moreover, severe colonic alteration, perturbations in the serum metabolic parameters associated with an oxidative stress state in the colonic mucosa, defined by overproduction of reactive oxygen species (ROS) and increased levels of plasma scavenging activity (PSA). Additionally, obesity exacerbated the severity of AA-induced UC promoting inflammation marked by the overexpression of pro-inflammatory cytokines. Significantly, treatment with SP provided notable protection against inflammation severity, reduced histopathological alterations, attenuated lipid peroxidation (MDA), and enhanced antioxidant enzyme activities (CAT, SOD, and GPX) along with non-enzymatic antioxidants (GSH and SH-G).

Conclusions

Thus, the antioxidant effects and anti-inflammatory proprieties of SP could be attributed to its richness in amino acids, which could potentially mitigate inflammation severity in obese subjects suffering from ulcerative colitis. These results imply that SP hold promise as a therapeutic agent for managing of UC, particularly in individuals with concomitant obesity. Understanding SP's mechanisms of action may lead novel treatment strategies for inflammatory bowel diseases and hyperlipidemia in medical research.

Nutraceutical strategies for alleviation of UVB phototoxicity

Ultraviolet B exposure to keratinocytes promotes carcinogenesis by inducing pyrimidine dimer lesions in DNA, suppressing the nucleotide excision repair mechanism required to fix them, inhibiting the apoptosis required for the elimination of initiated cells, and driving cellular proliferation. Certain nutraceuticals - most prominently spirulina, soy isoflavones, long-chain omega-3 fatty acids, the green tea catechin epigallocatechin gallate (EGCG) and Polypodium leucotomos extract - have been shown to oppose photocarcinogenesis, as well as sunburn and photoaging, in UVB-exposed hairless mice. It is proposed that spirulina provides protection in this regard via phycocyanobilin-mediated inhibition of Nox1-dependent NADPH oxidase; that soy isoflavones do so by opposing NF-κB transcriptional activity via oestrogen receptor-beta; that the benefit of eicosapentaenoic acid reflects decreased production of prostaglandin E2; and that EGCG counters UVB-mediated phototoxicity via inhibition of the epidermal growth factor receptor. The prospects for practical nutraceutical down-regulation of photocarcinogenesis, sunburn, and photoaging appear favourable.

Arthrospira (Spirulina) platensis feeding reduces the early stage of chemically induced rat colon carcinogenesis

Colorectal cancer is the third most diagnosed cancer worldwide and linked to dietary/lifestyle factors. Arthrospira (Spirulina) platensis (AP) contains bioactive compounds with beneficial effects in vivo/in vitro. We evaluated the effects of AP feeding against 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. Male Sprague Dawley rats were given subcutaneous injections of DMH (4 × 40 mg/kg body weight) (G1-G3) or vehicle (G4-G5) twice a week (weeks 3-4). During weeks 1-4, animals were fed a diet containing 1 % (G2) or 2 % (G3-G4) AP powder (w/w). After this period, all groups received a balanced diet until week 12. Some animals were euthanised after the last DMH injection (week 4) for histological, immunohistochemical (Ki-67, γ-H2AX and caspase-3) and molecular analyses (real time-PCR for 91 genes), while other animals were euthanised at week 12 for preneoplastic aberrant crypt foci (ACF) analysis. Both AP treatments (G2-G3) significantly decreased the DMH-induced increase in γ-H2AX (DNA damage) and caspase 3 (DNA damage-induced cell death) in colonic crypts at week 4. In addition, Cyp2e1 (Drug metabolism), Notch1, Notch2 and Jag1 genes (Notch pathway) and Atm, Wee1, Chek2, Mgmt, Ogg1 and Xrcc6 genes (DNA repair) were also down-regulated by 2 % AP feeding (G3) at week 4. A significant reduction in ACF development was observed in both AP-treated groups (G2-G3) at week 12. In conclusion, findings indicate that AP feeding reduced acute colonic damage after DMH, resulting in fewer preneoplastic lesions. Our study provided mechanistic insights on dietary AP-preventive effects against early colon carcinogenesis.

The Cytokines-Directed Roles of Spirulina for Radioprotection of Lacrimal Gland

PURPOSE

To evaluate the radioprotective effect of spirulina (SP) on the lacrimal glands after RAI treatment.

METHODS

A total of 30 rats were separated into control, RAI and SP group. The radioprotective effect of SP on lacrimal glands was evaluated with histopathological and cytopathological analysis. Lacrimal glands were analyzed for tumor necrosis factor alpha (TNF-α), interleukin-2 (IL-2), IL-4, IL-6, IL-10, nuclear factor-kappa B (NF-κB), total oxidant status (TOS) and total antioxidant capacity (TAC) levels.

RESULTS

RAI increased TNF-α (p = .001), IL-6 (p = .018), and NF-κB levels (p < .0005). Following the administration of SP, TNF-α (p < .0005), IL-4 (p = .026), and IL-6 (p = .006) levels decreased. RAI decreased the TAC levels (p = .001), and co-administration of SP increased the TAC level, but was not statistically significant. SP decreased the TOS level after RAI (p = .022)                .

CONCLUSIONS

SP protects lacrimal glands from RAI-induced damage.

Multifunctional Gold Helix Phototheranostic Biohybrid That Enables Targeted Image-Guided Photothermal Therapy in Breast Cancer

The preparation of multifunctional smart theranostic systems is commonly achieved through complicated strategies, limiting their biomedical applications. Spirulina platensis (SP) microalgae, as a natural helix with some of the intrinsic theranostic functionalities (e.g., fluorescent and photosensitizer pigments), not only facilitates the fabrication process but also guarantees their biosafety for clinical applications. Herein, the helical architecture of gold nanoparticles (AuNPs) based on a SP biotemplate was engineered as a safe, biodegradable, and tumor-targeted biohybrid for imaging-guided photothermal therapy (PTT) to combat triple-negative breast cancer. The quasi-spherical AuNPs were embedded throughout the SP cell (Au-SP) with minimally involved reagents, only by controlling the original morphological stability of SP through pH adjustment of the synthesis media. SP thiolation increased the localization of AuNPs selectively on the cell wall without using a reducing agent (Au-TSP). SP autofluorescence, along with the high X-ray absorption of AuNPs, was employed for dual-modal fluorescence and computed tomography (FL/CT) imaging. Furthermore, the theranostic efficacy of Au-SP was improved through a targeting process with folic acid (Au-SP@CF). High tumor inhibition effects were obtained by the excellent photothermal performance of Au-SP@CF in both in vitro and in vivo analyses. Of particular note, a comparison of the photothermal effect of Au-SP@CF with the naked SP and calcined form of Au-SP@CF not only indicated the key role of the helical architecture of AuNPs in achieving a high photothermal effect but also led to the formation of new gold microspiral biohybrids (Au-MS) over the calcination process. In short, well-controllable immobilization of AuNPs, appropriate biodegradability, good hemocompatibility, long-term biosafety, accurate imaging, high tumor suppression, and low tumor metastasis effects under laser irradiation are an array of intriguing attributes, making the proposed biohybrid a promising theranostic system for FL/CT-imaging-guided PTT.

Potential UV-Protective Effect of Freestanding Biodegradable Nanosheet-Based Sunscreen Preparations in XPA-Deficient Mice

Xeroderma pigmentosum (XP) is a rare autosomal recessive hereditary disorder. As patients with XP are deficient in nucleotide excision repair, they show severe photosensitivity symptoms. Although skin protection from ultraviolet (UV) radiation is essential to improve the life expectancy of such patients, the optimal protective effect is not achieved even with sunscreen application, owing to the low usability of the preparations. Nanosheets are two-dimensional nanostructures with a thickness in the nanometer range. The extremely large aspect ratios of the nanosheets result in high transparency, flexibility, and adhesiveness. Moreover, their high moisture permeability enables their application to any area of the skin for a long time. We fabricated preparations containing avobenzone (BMDBM) based on freestanding poly (L-lactic acid) (PLLA) nanosheets through a spin-coating process. Although monolayered PLLA nanosheets did not contain enough BMDBM to protect against UV radiation, the layered nanosheets, consisting of five discrete BMDBM nanosheets, showed high UV absorbance without lowering the adhesive strength against skin. Inflammatory reactions in XPA-deficient mice after UV radiation were completely suppressed by the application of BMDBM-layered nanosheets to the skin. Thus, the BMDBM layered nanosheet could serve as a potential sunscreen preparation to improve the quality of life of patients with XP.

Beneficial Effects of Spirulina Consumption on Brain Health

Spirulina is a microscopic, filamentous cyanobacterium that grows in alkaline water bodies. It is extensively utilized as a nutraceutical food supplement all over the world due to its high levels of functional compounds, such as phycocyanins, phenols and polysaccharides, with anti-inflammatory, antioxidant, immunomodulating properties both in vivo and in vitro. Several scientific publications have suggested its positive effects in various pathologies such as cardiovascular diseases, hypercholesterolemia, hyperglycemia, obesity, hypertension, tumors and inflammatory diseases. Lately, different studies have demonstrated the neuroprotective role of Spirulina on the development of the neural system, senility and a number of pathological conditions, including neurological and neurodegenerative diseases. This review focuses on the role of Spirulina in the brain, highlighting how it exerts its beneficial anti-inflammatory and antioxidant effects, acting on glial cell activation, and in the prevention and/or progression of neurodegenerative diseases, in particular Parkinson’s disease, Alzheimer’s disease and Multiple Sclerosis; due to these properties, Spirulina could be considered a potential natural drug.

Selective activation of TRPA1 ion channels by nitrobenzene skin sensitizers DNFB and DNCB

2, 4-dinitrofluorobenzene (DNFB) and 2, 4-dinitrochlorobenzene (DNCB) are well known as skin sensitizers that can cause dermatitis. DNFB has shown to more potently sensitize skin; however, how DNFB and DNCB cause skin inflammation at a molecular level and why this difference in their sensitization ability is observed remains unknown. In this study, we aimed to identify the molecular targets and mechanisms on which DNFB and DNCB act. We used a fluorescent calcium imaging plate reader in an initial screening assay before patch-clamp recordings for validation. Molecular docking in combination with site-directed mutagenesis was then carried out to investigate DNFB and DNCB binding sites in the TRPA1 ion channel that may be selectively activated by these tow sensitizers. We found that DNFB and DNCB selectively activated TRPA1 channel with EC₅₀ values of 2.3 ± 0.7 μM μM and 42.4 ± 20.9 μM, respectively. Single-channel recordings revealed that DNFB and DNCB increase the probability of channel opening and acts on three residues (C621, E625 and Y658) critical for TRPA1 activation. Our findings may not only help explain the molecular mechanism underlying the dermatitis and pruritus caused by chemicals like DNFB and DNCB, but also provide a molecular tool 7.5-fold more potent than the current TRPA1 activator allyl isothiocyanate (AITC) used for investigating TRPA1 channel pharmacology and pathology.

Effects of fluctuating temperature in open raceway ponds on the biomass accumulation and harvest efficiency of Spirulina in large-scale cultivation

It is of great significance to select strains with wide adaptability to temperature range for large-scale commercial cultivation of Spirulina. The aim of this study was to comprehend how the strain H-208 grew and whether this strain had any advantages in temperature adaptation compared with local production strain during the large-scale cultivation in Inner Mongolia. The results showed that the strain H-208 could adapt to the new environmental condition quickly, and the daily average biomass dry weight of strain H-208 was 49% and 52% more than that of production strain M-1 in first cycle (20.24 g/m2/day) and second cycle (16.90 g/m2/day) of acclimation experiment, respectively. The growth rate of strain H-208 was 0.055 and 0.066 g/L/day from July 22 to July 25 and from July 26 to July 29, respectively, while the growth rate of strain M-1 was only 0.036 and 0.032 g/L/day, respectively, during the same cultured days in 605-m2 raceway ponds before high temperature. The harvesting efficiency of H-208 and M-1 was 95.1% and 72.1% before high temperature, and that was 95.3% and 52.5% after being stressed by high temperature, respectively. Meanwhile, it was also observed that the filaments of the two strains contracted and their pitches were smaller than that before high temperature stress, especially the strain M-1. In 20-m2 raceway ponds of recovery experiment after high temperature, the percentage of daily average biomass dry weight of strain H-208 was 68% more than that of strain M-1, which demonstrated that strain H-208 could recover and grow rapidly, and its self-regulation ability was superior to that of strain M-1.

Evaluation of Acute Reactions on Mouse Skin Irradiated with 222 and 235 nm UV-C

Biological response and DNA damage following irradiation with shorter wavelengths in the UV‐C range were evaluated to investigate the safety at three wavelengths because of the recent emergence of germicidal equipment emitting short‐wavelength UV‐C for various purposes, including medical uses. To estimate an acceptable safety dose for human skin in the UV‐C range, especially short UV‐C, we studied the biological effects of 207, 222 and 235 nm UV‐C using albino hairless mice and evaluated the inflammatory reactions in the skin. To explore an appropriate indicator to evaluate the biological response, we employed determination of the minimal perceptible response dose (MPRD), by which any subtle cutaneous response; erythema, edema and scale could be observed by visual inspection. Erythema was rarely observed, but edema and scale formation were evident for short UV‐C wavelengths. The MPRD at 207, 222 and 235 nm was determined to be > 15, 15 and 2.0 kJ m⁻², respectively. These values could be thresholds and indicators for possible safety assessments. Our data suggest that the current human exposure limits for short UV‐C wavelengths below 254 nm are overly restrictive and should be reconsidered for future disinfection lamps with short UV‐C wavelengths.

Topical Application of Aronia melanocarpa Extract Rich in Chlorogenic Acid and Rutin Reduces UVB-Induced Skin Damage via Attenuating Collagen Disruption in Mice

Aronia melanocarpa, a black chokeberry, contains high levels of phenolic acids and polyphenolic flavonoids and displays antioxidative and anti-inflammatory effects. Through high-performance liquid chromatography for extracts from Aronia melanocarpa, we discovered that the extract contained chlorogenic acid and rutin as major ingredients. In this study, we examined the protective effects of the extract against ultraviolet B- (UVB)-induced photodamage in the dorsal skin of institute of cancer research (ICR) mice. Their dorsal skin was exposed to UVB, thereafter; the extract was topically applied once a day for seven days. Photoprotective properties of the extract in the dorsal skin were investigated by clinical skin severity score for skin injury, hematoxylin and eosin staining for histopathology, Masson's trichrome staining for collagens. In addition, we examined change in collagen type I and III, and matrix metalloproteinase (MMP)-1 and MMP-3 by immunohistochemistry. In the UVB-exposed mice treated with the extract, UVB-induced epidermal damage was significantly ameliorated, showing that epidermal thickness was moderated. In these mice, immunoreactivities of collagen type I and III were significantly increased, whereas immunoreactivities of MMP-1 and 3 were significantly decreased compared with those in the UVB-exposed mice. These results indicate that treatment with Aronia melanocarpa extract attenuates UV-induced photodamage by attenuating UVB-induced collagen disruption: these findings might be a result of the chlorogenic acid and rutin contained in the extract. Based on the current results, we suggest that Aronia melanocarpa can be a useful material for developing photoprotective adjuvant.

Inhibitors of DNA Glycosylases as Prospective Drugs

DNA glycosylases are enzymes that initiate the base excision repair pathway, a major biochemical process that protects the genomes of all living organisms from intrinsically and environmentally inflicted damage. Recently, base excision repair inhibition proved to be a viable strategy for the therapy of tumors that have lost alternative repair pathways, such as BRCA-deficient cancers sensitive to poly(ADP-ribose)polymerase inhibition. However, drugs targeting DNA glycosylases are still in development and so far have not advanced to clinical trials. In this review, we cover the attempts to validate DNA glycosylases as suitable targets for inhibition in the pharmacological treatment of cancer, neurodegenerative diseases, chronic inflammation, bacterial and viral infections. We discuss the glycosylase inhibitors described so far and survey the advances in the assays for DNA glycosylase reactions that may be used to screen pharmacological libraries for new active compounds.

Dose Effects of Orally Administered Spirulina Suspension on Colonic Microbiota in Healthy Mice

Oral supplemented nutraceuticals derived from food sources are surmised to improve the human health through interaction with the gastrointestinal bacteria. However, the lack of fundamental quality control and authoritative consensus (e.g., formulation, route of administration, dose, and dosage regimen) of these non-medical yet bioactive compounds are one of the main practical issues resulting in inconsistent individual responsiveness and confounded clinical outcomes of consuming nutraceuticals. Herein, we studied the dose effects of widely used food supplement, microalgae spirulina (Arthrospira platensis), on the colonic microbiota and physiological responses in healthy male Balb/c mice. Based on the analysis of 16s rDNA sequencing, compared to the saline-treated group, oral administration of spirulina once daily for 24 consecutive days altered the diversity, structure, and composition of colonic microbial community at the genus level. More importantly, the abundance of microbial taxa was markedly differentiated at the low (1.5 g/kg) and high (3.0 g/kg) dose of spirulina, among which the relative abundance of Clostridium XIVa, Desulfovibrio, Eubacterium, Barnesiella, Bacteroides, and Flavonifractor were modulated at various degrees. Evaluation of serum biomarkers in mice at the end of spirulina intervention showed reduced the oxidative stress and the blood lipid levels and increased the level of appetite controlling hormone leptin in a dose-response manner, which exhibited the significant correlation with differentially abundant microbiota taxa in the cecum. These findings provide direct evidences of dose-related modulation of gut microbiota and physiological states by spirulina, engendering its future mechanistic investigation of spirulina as potential sources of prebiotics for beneficial health effects via the interaction with gut microbiota.

Induced pluripotent stem cell-derived melanocyte precursor cells undergoing differentiation into melanocytes

Induced pluripotent stem cell (iPSC) technology offers a novel approach for conversion of human primary fibroblasts into melanocytes. During attempts to explore various protocols for differentiation of iPSCs into melanocytes, we found a distinct and self-renewing cell lineage that could differentiate into melanocytes, named as melanocyte precursor cells (MPCs). The MPCs exhibited a morphology distinctive from that of melanocytes, in lacking either the melanosomal structure or the melanocyte-specific marker genes MITF, TYR, and SOX10. In addition, gene expression studies in the MPCs showed high-level expression of WNT5A, ROR2, which are non-canonical WNT pathway markers, and its related receptor TGFβR2. In contrast, MPC differentiation into melanocytes was achieved by activating the canonical WNT pathway using the GSK3β inhibitor. Our data demonstrated the distinct characteristic of MPCs' ability to differentiate into melanocytes, and the underlying mechanism of interfacing between canonical WNT signaling pathway and non-canonical WNT signaling pathway.

Deltamethrin toxicity: A review of oxidative stress and metabolism

Deltamethrin is widely used worldwide due to its valuable insecticidal activity against pests and parasites. Increasing evidence has shown that deltamethrin causes varying degrees of toxicity. Moreover, oxidative stress and metabolism are highly correlated with toxicity. For the first time, this review systematically summarizes the deltamethrin toxicity mechanism from the perspective of oxidative stress, including deltamethrin-mediated oxidative damage, antioxidant status, oxidative signaling pathways and modulatory effects of antagonists, synergists and placebos on oxidative stress. Further, deltamethrin metabolism, including metabolites, metabolic enzymes and pathways and deltamethrin metabolite toxicity are discussed. This review will shed new light on deltamethrin toxicity mechanisms and provide effective strategies to ensure pest control and prevention of human and animal poisoning.

Crude protein from spirulina increases the viability of CCD‑986sk cells via the EGFR/MAPK signaling pathway

Spirulina, an edible blue-green alga, has great potential for various applications in human health, possibly including reduced skin aging. The mechanisms by which spirulina crude protein (SPCP) may influence human skin fibroblast viability are not yet understood; therefore, a human dermal fibroblast cell line (CCD-986sk) was used as a cell model system to study the influence of SPCP on human skin fibroblast viability. An enzyme-linked immunosorbent assay showed that collagen formation improved in SPCP-treated cells in a dose-dependent manner, while elastase activity was decreased. In addition, western blot analysis showed a dose-dependent decrease in the expression of the aging-associated gene matrix metalloproteinase-8, a collagen-degradative enzyme. It was also shown that SPCP upregulated epidermal growth factor receptor (EGFR) activity, leading to activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway. Together, these results demonstrated that SPCP increases human fibroblast viability by activation of the EGFR/MAPK signaling pathway. This contribution sheds light on the molecular mechanism for SPCP increasing the viability of human skin cell and provides a potential efficient cosmeceutical for protecting human skin.

Inflammation Due to Voriconazole-induced Photosensitivity Enhanced Skin Phototumorigenesis in Xpa-knockout Mice

Voriconazole is an antifungal agent and used as a prophylactic measure, especially in immunocompromised patients. However, there have been several reports of its adverse reactions, namely photosensitivity with intense inflammatory rashes and subsequent skin cancer development. To assess the effects of photosensitizing drugs voriconazole and hydrochlorothiazide (HCTZ) on the enhancement of UV-induced inflammatory responses and UV-induced tumorigenesis, we utilized Xpa-knockout mice, which is DNA repair-deficient and more susceptible to UV-induced inflammation and tumor development than wild-type mice. Administration of voriconazole prior to broadband UVB exposure significantly upregulated multiple inflammatory cytokines compared with the vehicle- or HCTZ-administered groups. Voriconazole administration along with chronic UVB exposure produced significantly higher number of skin tumors than HCTZ or vehicle in Xpa-knockout mice. Furthermore, the investigation of UVB-induced DNA damage using embryonic fibroblasts of Xpa-knockout mice revealed a significantly higher 8-oxo-7,8-dihydroguanine level in cells treated with voriconazole N-oxide, a voriconazole-metabolite during UV exposure. The data suggest that voriconazole plus UVB-induced inflammatory response may be related to voriconazole-induced skin phototumorigenesis.

Arthrospira Platensis - Potential in Dermatology and Beyond

The search for natural products with benefits for health in general and of potential for treating human disease has gained wider interest world-wide. Here, we analyse current data on the microalga Arthrospira platensis (AP), that has been used in nutrition since ancient times in Fare East and African communities, for medical purposes with a focus on dermatology. Extracts of AP have been investigated in vitro and in vivo. The alga is rich in proteins, lipopolysaccharides and gamma-linolenic acid. AP extracts, phycocyanin compounds and polysaccharide calcium spirulan (Ca-SP) have been evaluated in various models. It could be demonstrated, that AP has significant antioxidant activity, prevents viruses from entry into target cells and inhibits the colonisation of wounds by multi-resistant bacteria. Furthermore, anti-cancer activity was documented in models of oral cancer, melanoma, and UV-induced non-melanoma skin cancer.

Edible Cyanobacterial Genus Arthrospira: Actual State of the Art in Cultivation Methods, Genetics, and Application in Medicine

The cyanobacterial genus Arthrospira appears very conserved and has been divided into five main genetic clusters on the basis of molecular taxonomy markers. Genetic studies of seven Arthrospira strains, including genome sequencing, have enabled a better understanding of those photosynthetic prokaryotes. Even though genetic manipulations have not yet been performed with success, many genomic and proteomic features such as stress adaptation, nitrogen fixation, or biofuel production have been characterized. Many of above-mentioned studies aimed to optimize the cultivation conditions. Factors like the light intensity and quality, the nitrogen source, or different modes of growth (auto-, hetero-, or mixotrophic) have been studied in detail. The scaling-up of the biomass production using photobioreactors, either closed or open, was also investigated to increase the production of useful compounds. The richness of nutrients contained in the genus Arthrospira can be used for promising applications in the biomedical domain. Ingredients such as the calcium spirulan, immulina, C-phycocyanin, and γ-linolenic acid (GLA) show a strong biological activity. Recently, its use in the fight against cancer cells was documented in many publications. The health-promoting action of "Spirulina" has been demonstrated in the case of cardiovascular diseases and age-related conditions. Some compounds also have potent immunomodulatory properties, promoting the growth of beneficial gut microflora, acting as antimicrobial and antiviral. Products derived from Arthrospira were shown to successfully replace biomaterial scaffolds in regenerative medicine. Supplementation with the cyanobacterium also improves the health of livestock and quality of the products of animal origin. They were also used in cosmetic preparations.

Systematic Overview of Bacopa monnieri (L.) Wettst. Dominant Poly-Herbal Formulas in Children and Adolescents

Background: The Ayurvedic medicinal system employs a holistic approach to health, utilising the synergistic properties of organic resources. Research into the Ayurvedic herb Bacopa monnieri (L.) Wettst. (B.monnieri) has reported improvements in cognitive outcomes in child and adult populations. The aim of current review is to systematically assess and critically summarize clinical trials investigating B.monnieri-dominant poly-herbal formulas and their effects on the cognition, memory, learning, and behaviour in children and adolescents. Methods: Key word searches were performed using PubMed, Scopus, Cochrane Library, DHARA, and CINAHL for publications meeting inclusion criteria up to November 2017. There were no restrictions in study design. Effect sizes were calculated for all significant findings to allow for direct comparisons, and each study was evaluated on design quality. Cognitive and behavioural outcomes were grouped into validated constructs for cross-study comparison. Results: Nine trials met inclusion criteria. Five studies reported sufficient data for effect size analysis with most improvements reported in behavioural outcomes. True cognitive abilities and behavioural constructs were reviewed in six studies, with visual perception, impulsivity, and attention demonstrating the greatest improvements. The veracity of the evidence for the formulations reviewed is weakened by inconsistent statistical design and under-reporting of safety and tolerability data (44%). Conclusions: The current review extends research supporting B.monnieri as a cognitive enhancer and provides modest evidence for the use of B.monnieri in poly-herbal preparations for improving cognitive and behavioural outcomes in child and adolescent populations. Greater emphasis on statistical vigour and the reporting of tolerability data are essential for future trials to adequately document poly-herbal treatment efficacy.

Neuroprotective Activities of Spirulina platensis in the 6-OHDA Model of Parkinson's Disease Are Related to Its Anti-Inflammatory Effects

Spirulina platensis (SPI) is a cyanobacterium, presenting anti-inflammatory and antioxidant actions. Considering the importance of inflammation and oxidative stress in Parkinson's disease (PD), SPI neuroprotective effects were evaluated in a model of PD. Male Wistar rats were divided into: sham-operated (SO), untreated 6-OHDA and 6-OHDA treated with SPI (25 and 50 mg/kg, p.o.). The 6-OHDA was injected into the right striata and SPI treatments started 24 h later for 2 weeks. The SO and untreated 6-OHDA-lesioned groups were administered with distilled water, for the same period. Afterwards, the animals were subjected to the apomorphine-induced rotational test and euthanized for striatal measurements of DA and DOPAC, nitrite and TBARS and immunohistochemistry assays for TH, DAT, iNOS and COX-2. SPI reduced the apomorphine-induced rotational behavior, DA and DOPAC depletions and nitrite and TBARS increases, at its high dose. Furthermore, TH and DAT immunoreactivities in the lesioned striatum of the untreated 6-OHDA-lesioned group were attenuated by SPI. Similarly, immunoreactivities for iNOS and COX-2 were also decreased after SPI treatments. In conclusion, we showed that behavioral and neurochemical alterations in hemiparkinsonian rats were partly reversed by SPI, characterizing the neuroprotective potential of Spirulina and stimulating translational studies focusing on its use as an alternative treatment for PD.

Sunlight damage to cellular DNA: Focus on oxidatively generated lesions

The routine and often unavoidable exposure to solar ultraviolet (UV) radiation makes it one of the most significant environmental DNA-damaging agents to which humans are exposed. Sunlight, specifically UVB and UVA, triggers various types of DNA damage. Although sunlight, mainly UVB, is necessary for the production of vitamin D, which is necessary for human health, DNA damage may have several deleterious consequences, such as cell death, mutagenesis, photoaging and cancer. UVA and UVB photons can be directly absorbed not only by DNA, which results in lesions, but also by the chromophores that are present in skin cells. This process leads to the formation of reactive oxygen species, which may indirectly cause DNA damage. Despite many decades of investigation, the discrimination among the consequences of these different types of lesions is not clear. However, human cells have complex systems to avoid the deleterious effects of the reactive species produced by sunlight. These systems include antioxidants, that protect DNA, and mechanisms of DNA damage repair and tolerance. Genetic defects in these mechanisms that have clear harmful effects in the exposed skin are found in several human syndromes. The best known of these is xeroderma pigmentosum (XP), whose patients are defective in the nucleotide excision repair (NER) and translesion synthesis (TLS) pathways. These patients are mainly affected due to UV-induced pyrimidine dimers, but there is growing evidence that XP cells are also defective in the protection against other types of lesions, including oxidized DNA bases. This raises a question regarding the relative roles of the various forms of sunlight-induced DNA damage on skin carcinogenesis and photoaging. Therefore, knowledge of what occurs in XP patients may still bring important contributions to the understanding of the biological impact of sunlight-induced deleterious effects on the skin cells.

Protective effect of Arthrospira platensis extracts against ultraviolet B-induced cellular senescence through inhibition of DNA damage and matrix metalloproteinase-1 expression in human dermal fibroblasts

Ultraviolet (UV) light exposure causes skin photoaging, which is known to be preventable and controllable by application of UV-protective agents. In this study, we demonstrated, for the first time, that the extract of microalgae Arthrospira platensis has a reverse effect on UV-induced photodamage such as loss of cell viability, cellular senescence, DNA damage, and collagen destruction in dermal fibroblasts. Forty-eight extracts were prepared from the cell biomass by controlling culture light conditions, extract solvents, and disruption methods. Then, we analyzed their cytotoxicities using WST-1 assay and separated low and high cytotoxic extracts with normal human dermal fibroblasts (nHDFs). Using the low cytotoxic extracts, we performed UVB protection assay and selected the most effective extract demonstrating protective effect against UVB-induced nHDF damage. Flow cytometric analysis and senescence-associated (SA) β-galactosidase assay showed that pretreatment with the extract reversed UVB-induced G2/M phase cell cycle arrest and senescence in nHDFs. Furthermore, UVB-induced DNA damage in nHDFs, such as cyclobutane pyrimidine dimer formation, was significantly suppressed by the extract. Further, quantitative real-time PCR experiments revealed that the extract significantly inhibited UVB-induced upregulation of matrix metalloproteinase 1 (MMP1) and MMP3 expression in nHDFs. Therefore, we concluded that the microalgae extract can be a potential anti-photoaging agent.

CXCL1 Inhibition Regulates UVB-Induced Skin Inflammation and Tumorigenesis in Xpa-Deficient Mice

Xeroderma pigmentosum complementation group A is a hereditary disease characterized by early onset of skin cancers and freckle-like pigmented maculae in sun-exposed sites. Although the etiology of the predisposition to UVR-induced skin tumors in xeroderma pigmentosum complementation group A is well investigated as a repair deficiency in UVR-induced DNA damage, the mechanism of exaggerated sunburn in patients with xeroderma pigmentosum complementation group A and whether UVR-induced inflammation relates to a skin tumor-prone phenotype remains to be elucidated. Using gene profiling of xeroderma pigmentosum complementation group A model mice, Xpa-deficient mice, we found that expression of CXCL1 in the skin and blood of Xpa-deficient mice increased significantly after UVB exposure over even a limited area compared with that of wild-type mice. We administered CXCL1 neutralizing antibody or the antioxidant agent, N-acetylcysteine, to Xpa-deficient mice after UVB irradiation and found significant suppression of blood levels of CXCL1, ear swelling and erythema, the hallmarks of inflammation and neutrophil chemotaxis. Xpa-deficient mice treated with chronic UVB exposure plus administration of CXCL1 neutralizing antibody or N-acetylcysteine yielded many fewer skin tumors compared with the control group. This indicates that the UVB-induced strong inflammatory response of Xpa-deficient mice plays a role in skin tumor development, which could be suppressed by regulating chemokines such as CXCL1.

The antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina: an overview

Spirulina is a species of filamentous cyanobacteria that has long been used as a food supplement. In particular, Spirulina platensis and Spirulina maxima are the most important. Thanks to a high protein and vitamin content, Spirulina is used as a nutraceutical food supplement, although its other potential health benefits have attracted much attention. Oxidative stress and dysfunctional immunity cause many diseases in humans, including atherosclerosis, cardiac hypertrophy, heart failure, and hypertension. Thus, the antioxidant, immunomodulatory, and anti-inflammatory activities of these microalgae may play an important role in human health. Here, we discuss the antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina in both animals and humans, along with the underlying mechanisms. In addition, its commercial and regulatory status in different countries is discussed as well. Spirulina activates cellular antioxidant enzymes, inhibits lipid peroxidation and DNA damage, scavenges free radicals, and increases the activity of superoxide dismutase and catalase. Notably, there appears to be a threshold level above which Spirulina will taper off the antioxidant activity. Clinical trials show that Spirulina prevents skeletal muscle damage under conditions of exercise-induced oxidative stress and can stimulate the production of antibodies and up- or downregulate the expression of cytokine-encoding genes to induce immunomodulatory and anti-inflammatory responses. The molecular mechanism(s) by which Spirulina induces these activities is unclear, but phycocyanin and β-carotene are important molecules. Moreover, Spirulina effectively regulates the ERK1/2, JNK, p38, and IκB pathways. This review provides new insight into the potential therapeutic applications of Spirulina and may provide new ideas for future studies.

Calcium spirulan derived from Spirulina platensis inhibits herpes simplex virus 1 attachment to human keratinocytes and protects against herpes labialis

BACKGROUND

Chronic infections with herpes simplex virus (HSV) type 1 are highly prevalent in populations worldwide and cause recurrent oral lesions in up to 40% of infected subjects.

OBJECTIVE

We investigated the antiviral activity of a defined Spirulina platensis microalga extract and of purified calcium spirulan (Ca-SP), a sulfated polysaccharide contained therein.

METHODS

The inhibitory effects of HSV-1 were assessed by using a plaque reduction assay and quantitative PCR in a susceptible mammalian epithelial cell line and confirmed in human keratinocytes. Time-of-addition and attachment experiments and fluorescence detection of the HSV-1 tegument protein VP16 were used to analyze the mechanism of HSV-1 inhibition. Effects of Ca-SP on Kaposi sarcoma-associated herpesvirus/human herpes virus 8 replication and uptake of the ORF45 tegument protein were tested in human retinal pigment epithelial cells. In an observational trial the prophylactic effects of topically applied Ca-SP were compared with those of systemic and topical nucleoside analogues in 198 volunteers with recurrent herpes labialis receiving permanent lip makeup.

RESULTS

Ca-SP inhibited HSV-1 infection in vitro with a potency at least comparable to that of acyclovir by blocking viral attachment and penetration into host cells. Ca-SP also inhibited entry of Kaposi sarcoma-associated herpesvirus/human herpes virus 8. In the clinical model of herpes exacerbation, the prophylactic effect of a Ca-SP and microalgae extract containing cream was superior to that of acyclovir cream.

CONCLUSION

These data indicate a potential clinical use of Ca-SP containing Spirulina species extract for the prophylactic treatment of herpes labialis and suggest possible activity of Ca-SP against infections caused by other herpesviruses.

Spirulina platensis Lacks Antitumor Effect against Solid Ehrlich Carcinoma in Female Mice

Spirulina is a blue-green alga used as a dietary supplement. It has been shown to possess anti-inflammatory, antioxidant, and hepatoprotective properties. This study was designed to evaluate the antitumor effect of spirulina (200 and 800 mg/kg) against a murine model of solid Ehrlich carcinoma compared to a standard chemotherapeutic drug, 5-fluorouracil (20 mg/kg). Untreated mice developed a palpable solid tumor after 13 days. Unlike fluorouracil, spirulina at the investigated two dose levels failed to exert any protective effect. In addition, spirulina did not potentiate the antitumor effect of fluorouracil when they were administered concurrently. Interestingly, their combined administration resulted in a dose-dependent increase in mortality. The present study demonstrates that spirulina lacks antitumor effect against this model of solid Ehrlich carcinoma and increased mortality when combined with fluorouracil. However, the implicated mechanism is still elusive.

Current concept of photocarcinogenesis

Schematic pathway of UV induced inflammation and the formation of oxidative stress.

Oxidatively generated damage to cellular DNA by UVB and UVA radiation

This review article focuses on a critical survey of the main available information on the UVB and UVA oxidative reactions to cellular DNA as the result of direct interactions of UV photons, photosensitized pathways and biochemical responses including inflammation and bystander effects. UVA radiation appears to be much more efficient than UVB in inducing oxidatively generated damage to the bases and 2-deoxyribose moieties of DNA in isolated cells and skin. The UVA-induced generation of 8-oxo-7,8-dihydroguanine is mostly rationalized in terms of selective guanine oxidation by singlet oxygen generated through type II photosensitization mechanism. In addition, hydroxyl radical whose formation may be accounted for by metal-catalyzed Haber-Weiss reactions subsequent to the initial generation of superoxide anion radical contributes in a minor way to the DNA degradation. This leads to the formation of both oxidized purine and pyrimidine bases together with DNA single-strand breaks at the exclusion, however, of direct double-strand breaks. No evidence has been provided so far for the implication of delayed oxidative degradation pathways of cellular DNA. In that respect putative characteristic UVA-induced DNA damage could include single and more complex lesions arising from one-electron oxidation of the guanine base together with aldehyde adducts to amino-substituted nucleobases.