Polyphenols from Maackia amurensis Heartwood Protect Neuronal Cells from Oxidative Stress and Prevent Herpetic Infection.

Here, we continued the investigation of anti-HSV-1 activity and neuroprotective potential of 14 polyphenolic compounds isolated from Maackia amurensis heartwood. We determined the absolute configurations of asymmetric centers in scirpusin A (13) and maackiazin (10) as 7R,8R and 1″S,2″S, respectively. We showed that dimeric stilbens maackin (9) and scirpusin A (13) possessed the highest anti-HSV-1 activity among polyphenols 1-14. We also studied the effect of polyphenols 9 and 13 on the early stages of HSV-1 infection. Direct interaction with the virus (virucidal activity) was the main mechanism of the antiviral activity of these compounds. The neuroprotective potential of polyphenolic compounds from M. amurensis was studied using models of 6-hydroxydopamine (6-OHDA)-and paraquat (PQ)-induced neurotoxicity. A dimeric stilbene scirpusin A (13) and a flavonoid liquiritigenin (6) were shown to be the most active compounds among the tested polyphenols. These compounds significantly increased the viability of 6-OHDA-and PQ-treated Neuro-2a cells, elevated mitochondrial membrane potential and reduced the intracellular ROS level. We also found that scirpusin A (13), liquiritigenin (6) and retusin (3) considerably increased the percentage of live Neuro-2a cells and decreased the number of early apoptotic cells. Scirpusin A (13) was the most promising compound possessing both anti-HSV-1 activity and neuroprotective potential.

Protection Activity of 1,4-Naphthoquinones in Rotenone-Induced Models of Neurotoxicity.

The MTS cell viability test was used to screen a mini library of natural and synthetic 1,4-naphthoquinone derivatives (1,4-NQs) from marine sources. This screening identified two highly effective compounds, U-443 and U-573, which showed potential in protecting Neuro-2a neuroblastoma cells from the toxic effects of rotenone in an in vitro model of neurotoxicity. The selected 1,4-NQs demonstrated the capability to reduce oxidative stress by decreasing the levels of reactive oxygen species (ROS) and nitric oxide (NO) in Neuro-2a neuroblastoma cells and RAW 264.7 macrophage cells and displayed significant antioxidant properties in mouse brain homogenate. Normal mitochondrial function was restored and the mitochondrial membrane potential was also regained by 1,4-NQs after exposure to neurotoxins. Furthermore, at low concentrations, these compounds were found to significantly reduce levels of proinflammatory cytokines TNF and IL-1ß and notably inhibit the activity of cyclooxygenase-2 (COX-2) in RAW 264.7 macrophages. The results of docking studies showed that the 1,4-NQs were bound to the active site of COX-2, analogically to a known inhibitor of this enzyme, SC-558. Both substances significantly improved the behavioral changes in female CD1 mice with rotenone-induced early stage of Parkinson's disease (PD) in vivo. It is proposed that the 1,4-NQs, U-443 and U-573, can protect neurons and microglia through their potent anti-ROS and anti-inflammatory activities.

Phanogracilins A-C, New Bibenzochromenones of Crinoid Phanogenia gracilis (Hartlaub, 1890).

Three new bibenzochromenones named phanogracilins A-C (1-3) were isolated from the crinoid Phanogenia gracilis. The structure of 1 was established using X-ray crystallography as 5,5',6,6',8,8'-hexahydroxy-2,2'-dipropyl-4H,4'H-[7,9'-bibenzo[g]chromene]-4,4'-dione. This allowed us to assign reliably 2D NMR signals for compound 1 and subsequently for its isomer 2 that differed in the connecting position of two benzochromenone moieties (7,10' instead of 7,9'), and compound for 3 that differed in the length of the aliphatic chain of one of the fragments. Compound 4 was derived from 1 in alkaline conditions, and its structure was elucidated as 5,5',6',8,8'-pentahydroxy-2,2'-dipropyl-4H,4'H-[7,9'-bibenzo[g]chromene]-4,4',6,9-tetraone. Even though compounds 1-4 did not contain stereo centers, they possessed notable optical activity due to sterical hindrances, which limited the internal rotation of two benzochromenone fragments around C(7)-C(9'/10') bonds. Isolated bibenzochromenones 1-4 were tested for their antiradical, neuroprotective and antimicrobial activities. Compounds 1, 3 and 4 demonstrated significant antiradical properties towards ABTS radicals higher than the positive control trolox. Compounds 1 and 4 exhibited moderate neuroprotective activity, increasing the viability of rotenone-treated Neuro-2a cells at a concentration of 1 µM by 9.8% and 11.8%, respectively. Compounds 1 and 3 at concentrations from 25 to 100 µM dose-dependently inhibited the growth of Gram-positive bacteria S. aureus and yeast-like fungi C. albicans, and they also prevented the formation of their biofilms. Compounds 2 and 4 exhibited low antimicrobial activity.

Sulfated Triterpene Glycosides from the Far Eastern Sea Cucumber Cucumaria djakonovi: Djakonoviosides C1, D1, E1, and F1; Cytotoxicity against Human Breast Cancer Cell Lines; Quantitative Structure-Activity Relationships.

Four new mono- and trisulfated triterpene penta- and tetraosides, djakonoviosides C1 (1), D1 (2), E1 (3), and F1 (4) were isolated from the Far Eastern sea cucumber Cucumaria djakonovi (Cucumariidae, Dendrochirotida), along with six known glycosides found earlier in other Cucumaria species. The structures of unreported compounds were established on the basis of extensive analysis of 1D and 2D NMR spectra as well as by HR-ESI-MS data. The set of compounds contains six different types of carbohydrate chains including two new ones. Thus, djakonovioside C1 (1) is characterized by xylose as the second residue, that was a branchpoint in the pentasaccharide chain. Meanwhile, only quinovose and rarely glucose have been found earlier in pentasaccharide chains branched at C-2 of the second sugar unit. Djakonovioside E1 (3) is characterized by a tetrasaccharide trisulfated chain, with glucose as the second residue. So, in the series of isolated glycosides, three types of sugars in the second position were presented: the most common, quinovose-in six compounds; glucose-in three substances; and the rare xylose-in one glycoside. The set of aglycones was composed of holostane- and non-holostane-type polycyclic systems; the latter comprised normal and reduced side chains. Noticeably, isokoreoside A (9), isolated from C. djakonovi, was a single glycoside having a 9(11)-double bond, indicating two oxidosqualenecyclases are operating in the process of the biosynthesis of aglycones. Some of the glycosides from C. djakonovi, which were characterized by pentasaccharide branched chains containing one to three sulfate groups, are chemotaxonomic features of the representatives of the genus Cucumaria. The assortment of sugar parts of Cucumaria's glycosides was broadened with previously undescribed penta- and tetrasaccharide moieties. The metabolic network of sugar parts and aglycones is constructed based on biogenetic relationships. The cytotoxic action of compounds 1-10, isolated from C. djakonovi, against human breast cancer cell lines was investigated along with the hemolytic activity. Erythrocytes were, as usual, more sensitive to the membranolytic action of the glycosides than cancer cells. The triple-negative breast cancer MDA-MB-231 cell line was more vulnerable to the action of glycosides in comparison with the other tested cancer cells, while the MCF-7 cell line was less susceptible to cytotoxic action. Djakonovioside E1 (3) demonstrated selective action against ER-positive MCF-7 and triple-negative MDA-MB-231 cell lines, while the toxic effect in relation to normal mammary epithelial cells (MCF-10A) was absent. Cucumarioside A2-5 (6) inhibited the formation and growth of colonies of cancer cells to 44% and tumor cell migration to 85% of the control. Quantitative structure-activity relationships (QSAR) were calculated on the basis of the correlational analysis of the physicochemical properties and structural features of the glycosidic molecules and their membranolytic activity. QSAR revealed the extremely complex nature of such relationships, but these calculations correlated well with the observed SAR.

Holothurian triterpene glycoside cucumarioside A2-2 induces macrophages activation and polarization in cancer immunotherapy.

BACKGROUND: Despite intensive developments of adoptive T cell and NK cell therapies, the efficacy against solid tumors remains elusive. Our study demonstrates that macrophage-based cell therapy could be a potent therapeutic option against solid tumors. METHODS: To this end, we determine the effect of a natural triterpene glycoside, cucumarioside A2-2 (CA2-2), on the polarization of mouse macrophages into the M1 phenotype, and explore the antitumor activity of the polarized macrophage. The polarization of CA2-2-pretreated macrophages was analyzed by flow cytometry and confocal imaging. The anti-cancer activity of CA2-2 macrophages was evaluated against 4T1 breast cancer cells and EAC cells in vitro and syngeneic mouse model in vivo. RESULTS: Incubation of murine macrophages with CA2-2 led to polarization into the M1 phenotype, and the CA2-2-pretreated macrophages could selectively target and kill various types of cancer in vitro. Notably, loading near-infrared (NIR) fluorochrome-labeled nanoparticles, MnMEIO-mPEG-CyTE777, into macrophages substantiated that M1 macrophages can target and penetrate tumor tissues in vivo efficiently. CONCLUSION: In this study, CA2-2-polarized M1 macrophages significantly attenuated tumor growth and prolonged mice survival in the syngeneic mouse models. Therefore, ex vivo CA2-2 activation of mouse macrophages can serve as a useful model for subsequent antitumor cellular immunotherapy developments.

Assimiloside A, a Glycolipid with Immunomodulatory Activity from the Northwestern Pacific Marine Sponge Hymeniacidon assimilis.

Assimiloside A (1), an unprecedented marine glycolipid containing a γ-lactone of 4R,16,26R-trihydroxy C28 fatty acid as an aglycon and a trisaccharide carbohydrate moiety, was isolated from the marine sponge Hymeniacidon assimilis. Its structure was elucidated by NMR spectroscopy, mass spectrometry, chemical transformations, and ECD spectroscopy combined with time-dependent density functional theory calculations. Assimiloside A at nontoxic concentrations of 0.01-0.1 µM was shown to present lysosomal activity stimulation and intracellular reactive oxygen species level elevation in RAW 264.7 murine macrophages.

Tetracyclic 1,4-Naphthoquinone Thioglucoside Conjugate U-556 Blocks the Purinergic P2X7 Receptor in Macrophages and Exhibits Anti-Inflammatory Activity In Vivo.

P2X7 receptors (P2X7Rs) are ligand-gated ion channels that play a significant role in inflammation and are considered a potential therapeutic target for some inflammatory diseases. We have previously shown that a number of synthetic 1,4-naphthoquinones are capable of blocking P2X7Rs in neuronal and macrophage cells. In the present investigation, we have demonstrated the ability of the tetracyclic quinone-thioglucoside conjugate U-556, derived from 1,4-naphthoquinone thioglucoside, to inhibit ATP-induced Ca2+ influx and YO-PRO-1 dye uptake, which indicates blocking P2X7R in RAW 264.7 macrophages. This process was accompanied by the inhibition of ATP-induced reactive oxygen species production in macrophages, as well as the macrophage survival strengthening under ATP toxic effects. Nevertheless, U-556 had no noticeable antioxidant capacity. Naphthoquinone-thioglucoside conjugate U-556 binding to the extracellular part of the P2X7R was confirmed by SPR analysis, and the kinetic characteristics of this complex formation were established. Computer modeling predicted that U-556 binds the P2X7R allosteric binding site, topographically similar to that of the specific A438079 blocker. The study of biological activity in in vivo experiments shows that tetracylic conjugate significantly reduces inflammation provoked by carrageenan. The data obtained points out that the observed physiological effects of U-556 may be due to its ability to block the functioning of the P2X7R.

Djakonoviosides A, A1, A2, B1-B4 - Triterpene Monosulfated Tetra- and Pentaosides from the Sea Cucumber Cucumaria djakonovi: The First Finding of a Hemiketal Fragment in the Aglycones; Activity against Human Breast Cancer Cell Lines.

Seven new monosulfated triterpene glycosides, djakonoviosides A (1), A1 (2), A2 (3), and B1-B4 (4-7), along with three known glycosides found earlier in the other Cucumaria species, namely okhotoside A1-1, cucumarioside A0-1, and frondoside D, have been isolated from the far eastern sea cucumber Cucumaria djakonovi (Cucumariidae, Dendrochirotida). The structures were established on the basis of extensive analysis of 1D and 2D NMR spectra and confirmed by HR-ESI-MS data. The compounds of groups A and B differ from each other in their carbohydrate chains, namely monosulfated tetrasaccharide chains are inherent to group A and pentasaccharide chains with one sulfate group, branched by C-2 Qui2, are characteristic of group B. The aglycones of djakonoviosides A2 (3), B2 (5), and B4 (7) are characterized by a unique structural feature, a 23,16-hemiketal fragment found first in the sea cucumbers' glycosides. The biosynthetic pathway of its formation is discussed. The set of aglycones of C. djakonovi glycosides was species specific because of the presence of new aglycones. At the same time, the finding in C. djakonovi of the known glycosides isolated earlier from the other species of Cucumaria, as well as the set of carbohydrate chains characteristic of the glycosides of all investigated representatives of the genus Cucumaria, demonstrated the significance of these glycosides as chemotaxonomic markers. The membranolytic actions of compounds 1-7 and known glycosides okhotoside A1-1, cucumarioside A0-1, and frondoside D, isolated from C. djakonovi against human cell lines, including erythrocytes and breast cancer cells (MCF-7, T-47D, and triple negative MDA-MB-231), as well as leukemia HL-60 and the embryonic kidney HEK-293 cell line, have been studied. Okhotoside A1-1 was the most active compound from the series because of the presence of a tetrasaccharide linear chain and holostane aglycone with a 7(8)-double bond and 16ß-O-acetoxy group, cucumarioside A0-1, having the same aglycone, was slightly less active because of the presence of branching xylose residue at C-2 Qui2. Generally, the activity of the djakonoviosides of group A was higher than that of the djakonoviosides of group B containing the same aglycones, indicating the significance of a linear chain containing four monosaccharide residues for the demonstration of membranolytic action by the glycosides. All the compounds containing hemiketal fragments, djakonovioside A2 (3), B2 (5), and B4 (7), were almost inactive. The most aggressive triple-negative MDA-MB-231 breast cancer cell line was the most sensitive to the glycosides action when compared with the other cancer cells. Okhotoside A1-1 and cucumarioside A0-1 demonstrated promising effects against MDA-MB-231 cells, significantly inhibiting the migration, as well as the formation and growth, of colonies.

New Anti-Hypoxic Metabolites from Co-Culture of Marine-Derived Fungi Aspergillus carneus KMM 4638 and Amphichorda sp. KMM 4639.

The KMM 4639 strain was identified as Amphichorda sp. based on two molecular genetic markers: ITS and ß-tubulin regions. Chemical investigation of co-culture marine-derived fungi Amphichorda sp. KMM 4639 and Aspergillus carneus KMM 4638 led to the identification of five new quinazolinone alkaloids felicarnezolines A-E (1-5), a new highly oxygenated chromene derivative oxirapentyn M (6) and five previously reported related compounds. Their structures were established using spectroscopic methods and by comparison with related known compounds. The isolated compounds showed low cytotoxicity against human prostate and breast cancer cells but felicarnezoline B (2) protected rat cardiomyocytes H9c2 and human neuroblastoma SH-SY5Y cells against CoCl2-induced damage.

Phytoceramides from the Marine Sponge Monanchora clathrata: Structural Analysis and Cytoprotective Effects.

In our research on sphingolipids from marine invertebrates, a mixture of phytoceramides was isolated from the sponge Monanchora clathrata (Western Australia). Total ceramide, ceramide molecular species (obtained by RP-HPLC, high-performance liquid chromatography on reversed-phase column) and their sphingoid/fatty acid components were analyzed by NMR (nuclear magnetic resonance) spectroscopy and mass spectrometry. Sixteen new (1b, 3a, 3c, 3d, 3f, 3g, 5c, 5d, 5f, 5g, 6b-g) and twelve known (2b, 2e, 2f, 3b, 3e, 4a-c, 4e, 4f, 5b, 5e) compounds were shown to contain phytosphingosine-type backbones i-t17:0 (1), n-t17:0 (2), i-t18:0 (3), n-t18:0 (4), i-t19:0 (5), or ai-t19:0 (6), N-acylated with saturated (2R)-2-hydroxy C21 (a), C22 (b), C23 (c), i-C23 (d), C24 (e), C25 (f), or C26 (g) acids. The used combination of the instrumental and chemical methods permitted the more detailed investigation of the sponge ceramides than previously reported. It was found that the cytotoxic effect of crambescidin 359 (alkaloid from M. clathrata) and cisplatin decreased after pre-incubation of MDA-MB-231 and HL-60 cells with the investigated phytoceramides. In an in vitro paraquat model of Parkinson's disease, the phytoceramides decreased the neurodegenerative effect and ROS (reactive oxygen species) formation induced by paraquat in neuroblastoma cells. In general, the preliminary treatment (for 24 or 48 h) of the cells with the phytoceramides of M. clathrata was necessary for their cytoprotective functions, otherwise the additive damaging effect of these sphingolipids and cytotoxic compounds (crambescidin 359, cisplatin or paraquat) was observed.

Pectins from the sea grass Enhalus acoroides (L.f.) Royle: Structure, biological activity and ability to form nanoparticles.

Two pectins from the seagrass Enhalus acoroides (L.f.) Royle were isolated for the first time. Their structures and biological activities were investigated. NMR spectroscopy showed one of them to consist exclusively from the repeating →4-α-d-GalpUA→ residue (Ea1), while the other had a much more complex structure that also included 1→3-linked α-d-GalpUA residues, 1→4-linked ß-apiose residues and small amounts of galactose and rhamnose (Ea2). The pectin Ea1 showed noticeable dose-dependent immunostimulatory activity, the Ea2 fraction was less effective. Both pectins were used to create pectin-chitosan nanoparticles for the first time, and the influence of pectin/chitosan mass ratio on their size and zeta potential was investigated. Ea1 particles were slightly smaller than Ea2 particles (77 ± 16 nm vs 101 ± 12 nm) and less negatively charged (-23 mV vs -39 mV). Assessment of their thermodynamic parameters showed that only the second pectin could form nanoparticles at room temperature.

Absolute Stereochemistry and Cytotoxic Effects of Vismione E from Marine Sponge-Derived Fungus Aspergillus sp. 1901NT-1.2.2.

The metabolic profile of the Aspergillus sp. 1901NT-1.2.2 sponge-associated fungal strain was investigated using the HPLC MS technique, and more than 23 peaks in the HPLC MS chromatogram were detected. Only two minor peaks were identified as endocrocin and terpene derivative MS data from the GNPS database. The main compound was isolated and identified as known anthraquinone derivative vismione E. The absolute stereochemistry of vismione E was established for the first time using ECD and quantum chemical methods. Vismione E showed high cytotoxic activity against human breast cancer MCF-7 cells, with an IC50 of 9.0 µM, in comparison with low toxicity for normal human breast MCF-10A cells, with an IC50 of 65.3 µM. It was found that vismione E inhibits MCF-7 cell proliferation and arrests the cell cycle in the G1 phase. Moreover, the negative influence of vismione E on MCF-7 cell migration was detected. Molecular docking of vismione E suggested the IMPDH2 enzyme as one of the molecular targets for this anthraquinone derivative.

Carrageenans and Their Oligosaccharides from Red Seaweeds Ahnfeltiopsis flabelliformis and Mastocarpus pacificus (Phyllophoraceae) and Their Antiproliferative Activity.

Comparative structural analysis of gelling polysaccharides from A. flabelliformis and M. pacificus belonging to Phyllophoraceae and the effect of their structural features and molecular weight on human colon cancer cell lines (HT-29, DLD-1, HCT-116) was carried out. According to chemical analysis, IR and NMR spectroscopies, M. pacificus produces kappa/iota-carrageenan with a predominance of kappa units and minor amounts of mu and/or nu units, while the polysaccharide from A. flabelliformis is iota/kappa-carrageenan (predominance of iota units) and contains negligible amounts of beta- and nu-carrageenans. Iota/kappa- (Afg-OS) and kappa/iota-oligosaccharides (Mp-OS) were obtained from the original polysaccharides through mild acid hydrolysis. The content of more sulfated iota units in Afg-OS (iota/kappa 7:1) was higher than in Mp-OS (1.0:1.8). The poly- and oligosaccharides up to 1 mg/mL did not show a cytotoxic effect on all tested cell lines. Polysaccharides showed an antiproliferative effect only at 1 mg/mL. Oligosaccharides had a more pronounced effect on HT-29 and HCT-116 cells than the original polymers, while HCT-116 cells were slightly more sensitive to their action. Kappa/iota-oligosaccharides exhibit a greater antiproliferative effect and more strongly decrease the number of colonies forming in HCT-116 cells. At the same time, iota/kappa-oligosaccharides inhibit cell migration more strongly. Kappa/iota-oligosaccharides induce apoptosis in the SubG0 and G2/M phases, while iota/kappa-oligosaccharides in the SubG0 phase.

Recombinant Analogs of Sea Anemone Kunitz-Type Peptides Influence P2X7 Receptor Activity in Neuro-2a Cells.

Purinergic P2X7 receptors (P2X7) have now been proven to play an important role and represent an important therapeutic target in many pathological conditions including neurodegeneration. Here, we investigated the impact of peptides on purinergic signaling in Neuro-2a cells through the P2X7 subtype in in vitro models. We have found that a number of recombinant peptides, analogs of sea anemone Kunitz-type peptides, are able to influence the action of high concentrations of ATP and thereby reduce the toxic effects of ATP. The influx of calcium, as well as the fluorescent dye YO-PRO-1, was significantly suppressed by the studied peptides. Immunofluorescence experiments confirmed that the peptides reduce the P2X7 expression level in neuronal Neuro-2a cells. Two selected active peptides, HCRG1 and HCGS1.10, were found to specifically interact with the extracellular domain of P2X7 and formed stable complexes with the receptor in surface plasmon resonance experiments. The molecular docking approach allowed us to establish the putative binding sites of the most active HCRG1 peptide on the extracellular domain of the P2X7 homotrimer and propose a mechanism for regulating its function. Thus, our work demonstrates the ability of the Kunitz-type peptides to prevent neuronal death by affecting signaling through the P2X7 receptor.

Neuroprotective and Antiherpetic Properties of Polyphenolic Compounds from Maackia amurensis Heartwood.

In this study, we isolated a new isoflavanostilbene maackiapicevestitol (1) as a mixture of two stable conformers 1a and 1b as well as five previously known dimeric and monomeric stilbens: piceatannol (2), maackin (3), scirpusin A (4), maackiasine (5), and maackolin (6) from M. amurensis heartwood, using column chromatography on polyamide, silicagel, and C-18. The structures of these compounds were elucidated by NMR, HR-MS, and CD techniques. Maksar® obtained from M. amurensis heartwood and polyphenolics 1-6 possessed moderate anti-HSV-1 activity in cytopathic effect (CPE) inhibition and RT-PCR assays. A model of PQ-induced neurotoxicity was used to study the neuroprotective potential of polyphenolic compounds from M. amurensis. Maksar® showed the highest neuroprotective activity and increased cell viability by 18% at a concentration of 10 µg/mL. Maackolin (6) also effectively increased the viability of PQ-treated Neuro-2a cells and the value of mitochondrial membrane potential at concentrations up to 10 µΜ. Maksar® and compounds 1-6 possessed higher FRAP and DPPH-scavenging effects than quercetin. However, only compounds 1 and 4 at concentrations of 10 µM as well as Maksar® (10 µg/mL) statistically significantly reduced the level of intracellular ROS in PQ-treated Neuro-2a cells.

Anti-Inflammatory Activity of 1,4-Naphthoquinones Blocking P2X7 Purinergic Receptors in RAW 264.7 Macrophage Cells.

P2X7 receptors are ligand-gated ion channels activated by ATP and play a significant role in cellular immunity. These receptors are considered as a potential therapeutic target for the treatment of multiple inflammatory diseases. In the present work, using spectrofluorimetry, spectrophotometry, Western blotting and ELISA approaches, the ability of 1,4-naphthoquinone thioglucoside derivatives, compounds U-286 and U-548, to inhibit inflammation induced by ATP/LPS in RAW 264.7 cells via P2X7 receptors was demonstrated. It has been established that the selected compounds were able to inhibit ATP-induced calcium influx and the production of reactive oxygen species, and they also exhibited pronounced antioxidant activity in mouse brain homogenate. In addition, compounds U-286 and U-548 decreased the LPS-induced activity of the COX-2 enzyme, the release of pro-inflammatory cytokines TNF-α and IL-1ß in RAW 264.7 cells, and significantly protected macrophage cells against the toxic effects of ATP and LPS. This study highlights the use of 1,4-naphthoquinones as promising purinergic P2X7 receptor antagonists with anti-inflammatory activity. Based on the data obtained, studied synthetic 1,4-NQs can be considered as potential scaffolds for the development of new anti-inflammatory and analgesic drugs.

Anticancer Activity of the Marine Triterpene Glycoside Cucumarioside A2-2 in Human Prostate Cancer Cells.

Despite recent advances in the treatment of metastatic castration-resistant prostate cancer (CRPC), treatment is inevitably hampered by the development of drug resistance. Thus, new drugs are urgently needed. We investigated the efficacy, toxicity, and mechanism of action of the marine triterpene glycoside cucumarioside A2-2 (CA2-2) using an in vitro CRPC model. CA2-2 induced a G2/M-phase cell cycle arrest in human prostate cancer PC-3 cells and caspase-dependent apoptosis executed via an intrinsic pathway. Additionally, the drug inhibited the formation and growth of CRPC cell colonies at low micromolar concentrations. A global proteome analysis performed using the 2D-PAGE technique, followed by MALDI-MS and bioinformatical evaluation, revealed alterations in the proteins involved in cellular processes such as metastatic potential, invasion, and apoptosis. Among others, the regulation of keratin 81, CrkII, IL-1ß, and cathepsin B could be identified by our proteomics approach. The effects were validated on the protein level by a 2D Western blotting analysis. Our results demonstrate the promising anticancer activity of CA2-2 in a prostate cancer model and provide insights on the underlying mode of action.

The Anti-Inflammatory Effect of Carrageenan/Echinochrom Complex at Experimental Endotoxemia.

The anti-inflammatory effects of the CRG/Ech complex in LPS-induced endotoxemia were investigated in vivo in mice and in vitro in LPS-stimulated RAW 264.7 cells and peritoneal macrophages. The results indicated that the CRG/Ech complex suppressed the LPS-induced inflammatory response by reducing the production of ROS and NO in the macrophages. Furthermore, the in vivo experiment indicated that the CRG/Ech complex minimized disorders of the physiological and metabolic processes in mice subjected to LPS intoxication and reduced the levels of proinflammatory cytokines in the mouse serum. The preventive administration of the CRG/Ech complex to mice prevented endotoxin-induced damage in the mouse model of endotoxemia, increased the mice's resistance to LPS, and prevented increases in the levels of proinflammatory cytokines (TNFα). In this work, we showed by the molecular docking that Ech interacted with carrageenan, and that H-donor and H-acceptor bonds are involved in the formation of the complex.

Cytotoxic Drimane-Type Sesquiterpenes from Co-Culture of the Marine-Derived Fungi Aspergillus carneus KMM 4638 and Beauveria felina (=Isaria felina) KMM 4639.

Chemical investigation of a coculture of the marine-derived fungi Beauveria felina KMM 4639 and Aspergillus carneus KMM 4638 led to the identification of three new drimane-type sesquiterpenes, asperflavinoids B, D and E (2, 4, 5), and nine previously reported related compounds. The structures of these compounds were established using spectroscopic methods and by comparison with known analogues. We also investigated the cytotoxic activity of the isolated compounds against several cancer and normal cell lines. Asperflavinoid C (3) and ustusolate E (9) exerted a significant effect on human breast cancer MCF-7 cell viability, with IC50 values of 10 µM, and induced in caspase-dependent apoptosis and arrest of the MCF-7 cell cycle in the G2/M phase in these cells.

Kunitz-Type Peptides from Sea Anemones Protect Neuronal Cells against Parkinson's Disease Inductors via Inhibition of ROS Production and ATP-Induced P2X7 Receptor Activation.

Parkinson's disease (PD) is a socially significant disease, during the development of which oxidative stress and inflammation play a significant role. Here, we studied the neuroprotective effects of four Kunitz-type peptides from Heteractis crispa and Heteractis magnifica sea anemones against PD inductors. The peptide HCIQ1c9, which was obtained for the first time, inhibited trypsin less than other peptides due to unfavorable interactions of Arg17 with Lys43 in the enzyme. Its activity was reduced by up to 70% over the temperature range of 60-100 °C, while HCIQ2c1, HCIQ4c7, and HMIQ3c1 retained their conformation and stayed active up to 90-100 °C. All studied peptides inhibited paraquat- and rotenone-induced intracellular ROS formation, in particular NO, and scavenged free radicals outside the cells. The peptides did not modulate the TRPV1 channels but they affected the P2X7R, both of which are considered therapeutic targets in Parkinson's disease. HMIQ3c1 and HCIQ4c7 almost completely inhibited the ATP-induced uptake of YO-PRO-1 dye in Neuro-2a cells through P2X7 ion channels and significantly reduced the stable calcium response in these cells. The complex formation of the peptides with the P2X7R extracellular domain was determined via SPR analysis. Thus, these peptides may be considered promising compounds to protect neuronal cells against PD inductors, which act as ROS production inhibitors and partially act as ATP-induced P2X7R activation inhibitors.