Exploring the Bioactive Potential of Pisolithus (Basidiomycota): Comprehensive Insights into Antimicrobial, Anticancer, and Antioxidant Properties for Innovative Applications.

Addressing pressing health concerns, modern medical research seeks to identify new antimicrobials to combat drug resistance, novel molecules for cancer treatment, and antioxidants for inflammation-related diseases. Pisolithus (Basidiomycota) is a ubiquitous and widely distributed fungal genus in forest ecosystems, known for establishing ectomycorrhizal associations with a range of host plants, enhancing their growth, and conferring protection against biotic and abiotic stresses. Beyond ecological applications, Pisolithus yields bioactive compounds with medicinal potential. This comprehensive review explores the transversal biological activity of Pisolithus fungi, aiming to provide a thorough overview of their antimicrobial, anticancer, and antioxidant potential. The focus is on elucidating bioactive compounds within Pisolithus to trigger further research for innovative applications. Compounds from Pisolithus displayed antimicrobial activity against a broad spectrum of microorganisms, including antibiotic-resistant bacteria. The efficacy of Pisolithus-derived compounds matched established medications, emphasizing their therapeutic potential. In anticancer research, the triterpene pisosterol stood out with documented cytotoxicity against various cancer cell lines, showcasing promise for novel anticancer therapies. Pisolithus was also recognized as a potential source of antioxidants, with basidiocarps exhibiting high antioxidant activity. In vivo validation and comprehensive studies on a broader range of compounds, together with mechanistic insights into the mode of action of Pisolithus-derived compounds, are compelling areas for future research.

Stalling the Course of Neurodegenerative Diseases: Could Cyanobacteria Constitute a New Approach toward Therapy?

Neurodegenerative diseases (NDs) are characterized by progressive and irreversible neuronal loss, accompanied by a range of pathological pathways, including aberrant protein aggregation, altered energy metabolism, excitotoxicity, inflammation, and oxidative stress. Some of the most common NDs include Alzheimer's Disease (AD), Parkinson's Disease (PD), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), and Huntington's Disease (HD). There are currently no available cures; there are only therapeutic approaches that ameliorate the progression of symptoms, which makes the search for new drugs and therapeutic targets a constant battle. Cyanobacteria are ancient prokaryotic oxygenic phototrophs whose long evolutionary history has resulted in the production of a plethora of biomedically relevant compounds with anti-inflammatory, antioxidant, immunomodulatory, and neuroprotective properties, that can be valuable in this field. This review summarizes the major NDs and their pathophysiology, with a focus on the anti-neurodegenerative properties of cyanobacterial compounds and their main effects.

Tracing the Path between Mushrooms and Alzheimer's Disease-A Literature Review.

Alzheimer's disease (AD) is well-known among neurodegenerative diseases for the decline of cognitive functions, making overall daily tasks difficult or impossible. The disease prevails as the most common form of dementia and remains without a well-defined etiology. Being considered a disease of multifactorial origin, current targeted treatments have only managed to reduce or control symptoms, and to date, only two drugs are close to being able to halt its progression. For decades, natural compounds produced by living organisms have been at the forefront of research for new therapies. Mushrooms, which are well-known for their nutritional and medicinal properties, have also been studied for their potential use in the treatment of AD. Natural products derived from mushrooms have shown to be beneficial in several AD-related mechanisms, including the inhibition of acetylcholinesterase (AChE) and ß-secretase (BACE 1); the prevention of amyloid beta (Aß) aggregation and neurotoxicity; and the prevention of Tau expression and aggregation, as well as antioxidant and anti-inflammatory potential. Several studies in the literature relate mushrooms to neurodegenerative diseases. However, to the best of our knowledge, there is no publication that summarizes only AD data. In this context, this review aims to link the therapeutic potential of mushrooms to AD by compiling the anti-AD potential of different mushroom extracts or isolated compounds, targeting known AD-related mechanisms.

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 ß-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.

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.

Impact on the Mental and Physical Health of the Portuguese Population during the COVID-19 Confinement.

Confinement of the population has been one of the measures implemented by different governments to address the COVID-19 health crisis, and it has led to social isolation together with a disruption of daily activities. The aim of the study is to analyze psychological distress during the COVID-19 pandemic in Portugal. During the quarantine, a cross-sectional study was carried out on a sample of 2120 subjects over 18 years of age, resident and born in Portugal. Data were collected using a self-developed questionnaire that considered socio-demographic variables, physical symptoms, health conditions, and history of contact with COVID-19, as well as psychological alterations. The General Health Questionnaire (GHQ-12) was also included. Univariate and bivariate statistical analyses were performed. Predictive capacity was studied using logistic regression models. The results showed a higher percentage of individuals presenting psychological distress (57.2.0%), with a higher percentage identified among women (79.0%), and in people with a higher educational level (bachelor's + master's and doctorate) (75.8%). The predictor variables with the greatest weight were sex, educational level (graduation, master's, and doctorate), living with children or under 16 years of age, presence of symptoms, and quarantine in the last 14 days for having symptoms. Good self-assessment of health and working at home appear to be protective against psychological distress. These results highlight the impact of the COVID-19 pandemic on psychological distress and provide an opportunity to consider the need to implement specific multidisciplinary public health and mental health interventions in this pandemic situation.

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.

Bridging Cyanobacteria to Neurodegenerative Diseases: A New Potential Source of Bioactive Compounds against Alzheimer's Disease.

Neurodegenerative diseases (NDs) represent a drawback in society given the ageing population. Dementias are the most prevalent NDs, with Alzheimer's disease (AD) representing around 70% of all cases. The current pharmaceuticals for AD are symptomatic and with no effects on the progression of the disease. Thus, research on molecules with therapeutic relevance has become a major focus for the scientific community. Cyanobacteria are a group of photosynthetic prokaryotes rich in biomolecules with confirmed activity in pathologies such as cancer, and with feasible potential in NDs such as AD. In this review, we aimed to compile the research works focused in the anti-AD potential of cyanobacteria, namely regarding the inhibition of the enzyme ß-secretase (BACE1) as a fundamental enzyme in the generation of ß-amyloid (Aß), the inhibition of the enzyme acetylcholinesterase (AChE) lead to an increase in the availability of the neurotransmitter acetylcholine in the synaptic cleft and the antioxidant and anti-inflammatory effects, as phenomena associated with neurodegeneration mechanisms.

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 ß-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 was 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.

Norhierridin B, a New Hierridin B-Based Hydroquinone with Improved Antiproliferative Activity.

Hierridin B (6), a methylated hydroquinone isolated from the marine picocyanobacterium Cyanobium sp. LEGE 06113, moderately inhibited the growth of colon adenocarcinoma HT-29 cells. Aiming to improve the potential antitumor activity of this natural product, the demethylated analogue, norhierridin B (10), as well as its structurally-related quinone (9), were synthesized and evaluated for their growth inhibitory effect on a panel of human tumor cell lines, including the triple-negative breast cancer (TNBC) cells MDA-MB-231, SKBR3, and MDA-MB-468. Norhierridin B (10) showed a potent growth inhibitory effect on all cancer cell lines. Moreover, the growth inhibitory effect of compound 10 on MDA-MB-231 cells was associated with cell cycle arrest and apoptosis. Norhierridin B (10) interfered with several p53 transcriptional targets, increasing p21, Bax, and MDM2, while decreasing Bcl-2 protein levels, which suggested the potential activation of a p53 pathway. Altogether, these results evidenced a great improvement of the antitumor activity of hydroquinone 10 when compared to 6 and its structurally-related quinone (9). Notably, hydroquinone 10 displayed a prominent growth inhibitory activity against TNBC cells, which are characterized by high therapeutic resistance.

Structure of Hierridin C, Synthesis of Hierridins B and C, and Evidence for Prevalent Alkylresorcinol Biosynthesis in Picocyanobacteria.

Small, single-celled planktonic cyanobacteria are ubiquitous in the world's oceans yet tend not to be perceived as secondary metabolite-rich organisms. Here we report the isolation and structure elucidation of hierridin C, a minor metabolite obtained from the cultured picocyanobacterium Cyanobium sp. LEGE 06113. We describe a simple, straightforward synthetic route to the scarcely produced hierridins that relies on a key regioselective halogenation step. In addition, we show that these compounds originate from a type III PKS pathway and that similar biosynthetic gene clusters are found in a variety of bacterial genomes, most notably those of the globally distributed picocyanobacteria genera Prochlorococcus, Cyanobium and Synechococcus.

Cyanobacterial diversity held in microbial biological resource centers as a biotechnological asset: the case study of the newly established LEGE culture collection.

Cyanobacteria are a well-known source of bioproducts which renders culturable strains a valuable resource for biotechnology purposes. We describe here the establishment of a cyanobacterial culture collection (CC) and present the first version of the strain catalog and its online database (http://lege.ciimar.up.pt/). The LEGE CC holds 386 strains, mainly collected in coastal (48%), estuarine (11%), and fresh (34%) water bodies, for the most part from Portugal (84%). By following the most recent taxonomic classification, LEGE CC strains were classified into at least 46 genera from six orders (41% belong to the Synechococcales), several of them are unique among the phylogenetic diversity of the cyanobacteria. For all strains, primary data were obtained and secondary data were surveyed and reviewed, which can be reached through the strain sheets either in the catalog or in the online database. An overview on the notable biodiversity of LEGE CC strains is showcased, including a searchable phylogenetic tree and images for all strains. With this work, 80% of the LEGE CC strains have now their 16S rRNA gene sequences deposited in GenBank. Also, based in primary data, it is demonstrated that several LEGE CC strains are a promising source of extracellular polymeric substances (EPS). Through a review of previously published data, it is exposed that LEGE CC strains have the potential or actual capacity to produce a variety of biotechnologically interesting compounds, including common cyanotoxins or unprecedented bioactive molecules. Phylogenetic diversity of LEGE CC strains does not entirely reflect chemodiversity. Further bioprospecting should, therefore, account for strain specificity of the valuable cyanobacterial holdings of LEGE CC.

Single-Dose Azithromycin for the Treatment of Haemophilus ducreyi Skin Ulcers in Papua New Guinea.

BACKGROUND: Haemophilus ducreyi (HD) and Treponema pallidum subspecies pertenue (TP) are major causative agents of cutaneous ulcer (CU) in the tropics. Azithromycin is recommended to treat sexually transmitted HD infections and has good in vitro activity against HD strains from both genital and skin ulcers. We investigated the efficacy of oral single-dose azithromycin on HD-CU. METHODS: We conducted a community-based cohort study in Lihir Island, Papua New Guinea, from October 2014 through May 2016. Consenting patients with skin ulcers >1 cm in diameter were eligible for this study and had collected a lesional swab for polymerase chain reaction (PCR). All participants were treated with single-dose azithromycin (30 mg/kg) and were followed up for assessment of clinical resolution. We retrospectively classified patients according to PCR results into HD, TP, and PCR-negative groups. The primary endpoint was healing rates of HD-CU at 14 days after treatment. RESULTS: We obtained full outcome data from 246 patients; 131 (53.3%) were HD PCR positive, 37 (15.0%) were TP positive, and 78 (31.7%) were negative for all tests. Healing rates were 88.5% (95% confidence interval [CI], .82-.93) in the HD group, 78.4% [95% CI, .63-.89] in the TP group, and 74.4% (95% CI, .64-.83) in the PCR-negative group. If we included the participants with improved ulcers, the healing rates increased to 94.7%, 97.3%, and 89.7% respectively. HD cases classified as not healed all converted to HD-negative PCR. CONCLUSIONS: Based upon clinical resolution and PCR conversion to HD negative, a single oral dose of azithromycin is efficacious for the treatment of HD-CU. These results have implications for the treatment of individual patients and for the use of antibiotics in public health strategies to control CU in the tropics.

Using early life stages of marine animals to screen the toxicity of priority hazardous and noxious substances.

This study provides toxicity values for early life stages (ELS) of two phylogenetically distinct marine animal taxa, the sea urchin (Paracentrotus lividus), a deuterostome invertebrate, and the turbot (Scophthalmus maximus), a vertebrate (teleost), when challenged by six hazardous and noxious substances (HNS): aniline, butyl acrylate, m-cresol, cyclohexylbenzene, hexane and trichloroethylene. The aim of the study was to provide preliminary information on toxic effects of representative and relevant priority HNS to assess the risk posed by spills to marine habitats and therefore improve preparedness and the response at the operational level. Selection criteria to include each compound in the study were (1) inclusion in the HASREP (2005) list; (2) presence on the priority list established by Neuparth et al. (2011); (3) paucity of toxicological data (TOXnet and ECOTOX) for marine organisms; (4) behaviour in the water according to the categories defined by the European Behaviour classification system (GESAMP 2002), by selecting compounds with different behaviours in water; and (5) physicochemical and toxicological properties, where available, in order to anticipate the most toxic compounds. Aniline and m-cresol were the most toxic compounds with no observed apical effect concentration (NOAEC) values for sea urchin ranging between 0.01 and 0.1 mg/L, followed by butyl acrylate and cyclohexylbenzene with NOAECs ranging between 0.1 and 1.0 mg/L and trichloroethylene with NOAEC values that were in the range between 1 and 10 mg/L, reflecting their behaviour in water, mostly vapour pressure, but also solubility and log Kow. Hexane was toxic only for turbot embryos, due to its neurotoxic effects, and not for sea urchin larvae, at concentrations in the range between 1 and 10 mg/L. The concentrations tested were of the same order of magnitude for both species, and it was observed that sea urchin embryos (length of the longest arm) are more sensitive than turbot eggs larvae (hatching and cumulative mortality rates) to the HNS tested (except hexane). For this specific compound, concentrations up to 70 mg/L were tested in sea urchin larvae and no effects were observed on the length of the larvae. Both tests were found to be complementary depending on behaviour in water and toxicity target of the compounds analysed.

Screening the Toxicity of Selected Personal Care Products Using Embryo Bioassays: 4-MBC, Propylparaben and Triclocarban.

Recently, several emerging pollutants, including Personal Care Products (PCPs), have been detected in aquatic ecosystems, in the ng/L or µg/L range. Available toxicological data is limited, and, for certain PCPs, evidence indicates a potential risk for the environment. Hence, there is an urgent need to gather ecotoxicological data on PCPs as a proxy to improve risk assessment. Here, the toxicity of three different PCPs (4-Methylbenzylidene Camphor (4-MBC), propylparaben and triclocarban) was tested using embryo bioassays with Danio rerio (zebrafish) and Paracentrotus lividus (sea urchin). The No Observed Effect Concentration (NOEC) for triclocarban was 0.256 µg/L for sea urchin and 100 µg/L for zebrafish, whereas NOEC for 4-MBC was 0.32 µg/L for sea urchin and 50 µg/L for zebrafish. Both PCPs impacted embryo development at environmentally relevant concentrations. In comparison with triclocarban and 4-MBC, propylparaben was less toxic for both sea urchin (NOEC = 160 µg/L) and zebrafish (NOEC = 1000 µg/L). Overall, this study further demonstrates the sensitivity of embryo bioassays as a high-throughput approach for testing the toxicity of emerging pollutants.

Hierridin B Isolated from a Marine Cyanobacterium Alters VDAC1, Mitochondrial Activity, and Cell Cycle Genes on HT-29 Colon Adenocarcinoma Cells.

BACKGROUND: Hierridin B was isolated from a marine cyanobacterium Cyanobium sp. strain and induced cytotoxicity selectively in HT-29 adenocarcinoma cells. The underlying molecular mechanism was not yet elucidated. METHODS: HT-29 cells were exposed to the IC50 concentration of hierridin B (100.2 µM) for 48 h. Non-targeted proteomics was performed using 2D gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The mRNA expression of apoptotic and cell cycle genes were analyzed by real-time PCR. Automated quantification of 160 cytoplasm and mitochondrial parameter was done by fluorescence microscopy using CellProfiler software. RESULTS: Proteomics identified 21 significant different proteins, which belonged to protein folding/synthesis and cell structure amongst others. Increase of VDAC1 protein responsible for formation of mitochondrial channels was confirmed by mRNA expression. A 10-fold decrease of cytoskeleton proteins (STMN1, TBCA) provided a link to alterations of the cell cycle. CCNB1 and CCNE mRNA were decreased two-fold, and P21CIP increased 10-fold, indicative of cell cycle arrest. Morphological analysis of mitochondrial parameter confirmed a reduced mitochondrial activity. CONCLUSION: Hierridin B is a potential anticancer compound that targets mitochondrial activity and function.

Bartolosides E-K from a Marine Coccoid Cyanobacterium.

The glycosylated and halogenated dialkylresorcinol (DAR) compounds bartolosides A-D (1-4) were recently discovered from marine cyanobacteria and represent a novel family of glycolipids, encoded by the brt biosynthetic gene cluster. Here, we report the isolation and NMR- and MS-based structure elucidation of monoglycosylated bartolosides E-K (5-11), obtained from Synechocystis salina LEGE 06099, a strain closely related to the cyanobacterium that produces the diglycosylated 2-4. In addition, a genome region containing orthologues of brt genes was identified in this cyanobacterium. Interestingly, the major bartoloside in S. salina LEGE 06099 was 1 (above 0.5% dry wt), originally isolated from the phylogenetically distant filamentous cyanobacterium Nodosilinea sp. LEGE 06102. Compounds 5-11 are analogues of 1, with different alkyl chain lengths or halogenation patterns. Their structures and the organization of the brt genes suggest that the DAR-forming ketosynthase BrtD can generate structural diversity by accepting fatty acyl-derived substrates of varying length. Compound 9 features a rare midchain gem-dichloro moiety, indicating that the putative halogenase BrtJ is able to act twice on the same midchain carbon.

Insights into the potential of picoplanktonic marine cyanobacteria strains for cancer therapies - Cytotoxic mechanisms against the RKO colon cancer cell line.

PURPOSE: In this work, we analysed the potential of picoplanktonic marine cyanobacteria strains as a source of anticancer compounds by elucidating the cytotoxic mechanisms of an ethyl acetate fraction of Cyanobium sp. (LEGE06113) and the Synechocystis salina (LEGE06155) on the RKO colon adenocarcinoma cell line. METHODS: Cytotoxicity was analysed by MTT. Effects on cells were evaluated by mRNA expression of cell cycle and apoptotic genes, flow cytometry (cell cycle), qualitative and quantitative fluorescence microscopy (apoptosis), and quantitative proteomics. RESULTS: IC50 values were 27.01 and 8.03 µg/ml for Cyanobium sp., and 37.71 and 17.17 µg/ml for Synechocystis salina, after 24 h and 48 h, respectively. Exposure to the Cyanobium sp. fraction increased 2.5 fold BCL-2 mRNA expression (p < 0.05), and altered proteins (13, p < 0.05) belonged to apoptosis (PSMA5, PSMA7, TPT1, UBE2K), cell cycle (EIF4E, PCNA), cellular metabolism (AHSG, GLO1, ATP5H, HSP90AB1, NME1, HNRNPC) and cell structure (KRT10). Exposure to the Synechocystis salina fraction decreased 2fold CCNB1 mRNA expression (p < 0.05). Accordingly, flow cytometry demonstrated a decrease of cells in the G0/G1 and S phase (p < 0.05), indicating a cell cycle arrest at the G2/M transition. Fluorescence microscopy confirmed a higher level of apoptosis compared to the solvent control group (p < 0.01). Altered proteins (6, p < 0.05) belonged to apoptosis (HSPD1, UBE2K), protein metabolism (PKM, PDIA3) and cell structure (KRT10, KRT1). CONCLUSION: Since induction of cytotoxicity is a very broad parameter, the study demonstrates the potential of picocyanobacteria to produce bioactive compounds that target cancer cells via different molecular mechanisms.

Neofiscalin A and fiscalin C are potential novel indole alkaloid alternatives for the treatment of multidrug-resistant Gram-positive bacterial infections.

Ten indole alkaloids were obtained from the marine sponge-associated fungus Neosartorya siamensis KUFA 0017. We studied the antimicrobial properties of these and of three other compounds previously isolated from the soil fungus N. siamensis KUFC 6349. Only neofiscalin A showed antimicrobial activity against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE); with a minimum inhibitory concentration (MIC) of 8 µg mL(-1) against both strains. Another compound, fiscalin C, presented synergistic activity against MRSA when combined with oxacillin, although alone showed no antibacterial effect. Moreover, neofiscalin A, when present at sub-MICs, hampered the ability of both MRSA and VRE strains to form a biofilm. Additionally, the biofilm inhibitory concentration values of neofiscalin A against the MRSA and VRE isolates were 96 and 80 µg mL(-1), respectively. At a concentration of 200 µg mL(-1), neofiscalin A was able to reduce the metabolic activity of the biofilms by ∼50%. One important fact is that our results also showed that neofiscalin A had no cytotoxicity against a human brain capillary endothelial cell line.