Bioaccumulation of inorganic and organic mercury in the cuttlefish Sepia officinalis: Influence of ocean acidification and food type.

The bioaccumulation of mercury (Hg) in marine organisms through various pathways has not yet been fully explored, particularly in cephalopods. This study utilises radiotracer techniques using the isotope 203Hg to investigate the toxicokinetics and the organotropism of waterborne inorganic Hg (iHg) and dietary inorganic and organic Hg (methylHg, MeHg) in juvenile common cuttlefish Sepia officinalis. The effect of two contrasting CO2 partial pressures in seawater (400 and 1600 µatm, equivalent to pH 8.08 and 7.54, respectively) and two types of prey (fish and shrimp) were tested as potential driving factors of Hg bioaccumulation. After 14 days of waterborne exposure, juvenile cuttlefish showed a stable concentration factor of 709 ± 54 and 893 ± 117 at pH 8.08 and 7.54, respectively. The accumulated dissolved i203Hg was depurated relatively rapidly with a radiotracer biological half-life (Tb1/2) of 44 ± 12 and 55 ± 16 days at pH 8.08 and 7.54, respectively. During the whole exposure period, approximately half of the i203Hg was found in the gills, but i203Hg also increased in the digestive gland. When fed with 203Hg-radiolabelled prey, cuttlefish assimilated almost all the Hg provided (>95%) independently of the prey type. Nevertheless, the prey type played a major role on the depuration kinetics with Hg Tb1/2 approaching infinity in fish fed cuttlefish vs. 25 days in shrimp fed cuttlefish. Such a difference is explained by the different proportion of Hg species in the prey, with fish prey containing more than 80% of MeHg vs. only 30% in shrimp. Four days after ingestion of radiolabelled food, iHg was primarily found in the digestive organs while MeHg was transferred towards the muscular tissues. No significant effect of pH/pCO2 variation was observed during both the waterborne and dietary exposures on the bioaccumulation kinetics and tissue distribution of i203Hg and Me203Hg. Dietary exposure is the predominant pathway of Hg bioaccumulation in juvenile cuttlefish.

High conductivity Sepia melanin ink films for environmentally benign printed electronics.

Melanins (from the Greek µÎ­λας, mélas, black) are bio-pigments ubiquitous in flora and fauna. Eumelanin is an insoluble brown-black type of melanin, found in vertebrates and invertebrates alike, among which Sepia (cuttlefish) is noteworthy. Sepia melanin is a type of bio-sourced eumelanin that can readily be extracted from the ink sac of cuttlefish. Eumelanin features broadband optical absorption, metal-binding affinity and antioxidative and radical-scavenging properties. It is a prototype of benign material for sustainable organic electronics technologies. Here, we report on an electronic conductivity as high as 10-3 S cm-1 in flexographically printed Sepia melanin films; such values for the conductivity are typical for well-established high-performance organic electronic polymers but quite uncommon for bio-sourced organic materials. Our studies show the potential of bio-sourced materials for emerging electronic technologies with low human- and eco-toxicity.

Sulfation of chitosan from Sepia kobiensis as potential anticoagulant and antibacterial molecule.

The present work aimed to synthesis of chitin, chitosan and sulfation of chitosan from cuttlebone of cuttlefish Sepia kobiensis. Principally chitin was extracted through sequential processes of demineralisation and deproteinzation. Then chitosan was synthesized by a deacetylation and finally sulfated at semi-heterogeneous condition using chlorosulfonic acid in N,N-dimethylformamide. The synthesized macromolecules were characterized for its structural, physical and thermal (CHN, DDA, FT-IR, NMR, XRD, Viscometric analysis, SEM and DSC) properties. Apart from anticoagulant potential of the sulfated chitosan was tested using human plasma by means of activated partial thromboplastin time (APTT) and prothrombin time (PT). Further sulfated chitosan was tested for antibacterial potential by well diffusion method against eleven human pathogenic clinical isolates of both Gram positive and Gram-negative strains and minimum inhibitory concentrations (MIC) was calculated accordingly. The results of this study revealed the effectiveness of the sulfated chitosan at semi-heterogeneous conditions as a potent antibacterial and anticoagulant molecule.

Effects of a sulfated glycosaminoglycan from Sepia esculenta ink on transcriptional and metabolic profiles of Saccharomyces cerevisiae.

Four fractions of water-extracted Sepia esculenta ink polysaccharides (SIP) were separated by dicthylaminoethy (DEAE) cellulose chromatography. The eluted fraction with the highest yield was characterized as a sulfate-rich glycosaminoglycan named SIP-IV. According to the analysis of laser scattering and refractive index signals, SIP-IV was determined to be 14.4 kDa and spherical molecular conformation in salt solution. SIP-IV is composed of fucose, galactosamine, glucosamine, mannose and glucuronic acid with a molar ratio of 5.1:7.3:3.8:1:4.4, which is obviously different from reported SIPs. SIP-IV promoted yeast proliferation and intercellular antioxidant level. Based on multi-omics strategy, data of transcriptome analysis suggested that growth promotion of SIP-IV on Saccharomyces cerevisiae might be attributed to regulation of Rho protein signal transduction, nuclear autophagy and nitrogen utilization. Combined with the metabolome results, SIP-IV also re-profiled metabolism of amino acids and phospholipids in yeast cells.

Mechanical design of the highly porous cuttlebone: A bioceramic hard buoyancy tank for cuttlefish.

Cuttlefish, a unique group of marine mollusks, produces an internal biomineralized shell, known as cuttlebone, which is an ultra-lightweight cellular structure (porosity, ∼93 vol%) used as the animal's hard buoyancy tank. Although cuttlebone is primarily composed of a brittle mineral, aragonite, the structure is highly damage tolerant and can withstand water pressure of about 20 atmospheres (atm) for the species Sepia officinalis Currently, our knowledge on the structural origins for cuttlebone's remarkable mechanical performance is limited. Combining quantitative three-dimensional (3D) structural characterization, four-dimensional (4D) mechanical analysis, digital image correlation, and parametric simulations, here we reveal that the characteristic chambered "wall-septa" microstructure of cuttlebone, drastically distinct from other natural or engineering cellular solids, allows for simultaneous high specific stiffness (8.4 MN⋅m/kg) and energy absorption (4.4 kJ/kg) upon loading. We demonstrate that the vertical walls in the chambered cuttlebone microstructure have evolved an optimal waviness gradient, which leads to compression-dominant deformation and asymmetric wall fracture, accomplishing both high stiffness and high energy absorption. Moreover, the distribution of walls is found to reduce stress concentrations within the horizontal septa, facilitating a larger chamber crushing stress and a more significant densification. The design strategies revealed here can provide important lessons for the development of low-density, stiff, and damage-tolerant cellular ceramics.

Preventive Effects of Three Polysaccharides on the Oxidative Stress Induced by Acrylamide in a Saccharomyces cerevisiae Model.

Saccharomyces cerevisiae was used as a model to explore the preventive effect of two marine polysaccharides separately derived from Sepia esculenta ink (SIP) and Laminaria japonica (FL) as well as one terrestrial polysaccharides from Eleocharis tuberosa peel (WCPP) on toxic injury induced by acrylamide (AA). The growth of yeast was evaluated by kinetics indexes including doubling time, lag phase and maximum proliferation density. Meanwhile, intracellular redox state was determined by contents of MDA and GSH, and SOD activity. The results showed that AA inhibited yeast growth and destroyed the antioxidant defense system. Supplement with polysaccharides, the oxidative damage of cells was alleviated. According to the growth recovery of yeast, FL and WCPP had similar degree of capacity against AA associated cytotoxicity, while SIP was 1.5~2 folds as strong as FL and WCPP. SIP and FL significantly reduced production of MDA by AA administration. Moreover, SIP, FL and WCPP increased SOD activity and repressed GSH depletion caused by AA.

Histamine and histidine decarboxylase in the olfactory system and brain of the common cuttlefish Sepia officinalis (Linnaeus, 1758).

Cephalopods are radically different from any other invertebrate. Their molluscan heritage, innovative nervous system, and specialized behaviors create a unique blend of characteristics that are sometimes reminiscent of vertebrate features. For example, despite differences in the organization and development of their nervous systems, both vertebrates and cephalopods use many of the same neurotransmitters. One neurotransmitter, histamine (HA), has been well studied in both vertebrates and invertebrates, including molluscs. While HA was previously suggested to be present in the cephalopod central nervous system (CNS), Scaros, Croll, and Baratte only recently described the localization of HA in the olfactory system of the cuttlefish Sepia officinalis. Here, we describe the location of HA using an anti-HA antibody and a probe for histidine decarboxylase (HDC), a synthetic enzyme for HA. We extended previous descriptions of HA in the olfactory organ, nerve, and lobe, and describe HDC staining in the same regions. We found HDC-positive cell populations throughout the CNS, including the optic gland and the peduncle, optic, dorso-lateral, basal, subvertical, frontal, magnocellular, and buccal lobes. The distribution of HA in the olfactory system of S. officinalis is similar to the presence of HA in the chemosensory organs of gastropods but is different than the sensory systems in vertebrates or arthropods. However, HA's widespread abundance throughout the rest of the CNS of Sepia is a similarity shared with gastropods, vertebrates, and arthropods. Its widespread use with differing functions across Animalia provokes questions regarding the evolutionary history and adaptability of HA as a transmitter.

Effect of Carboxymethylation and Phosphorylation on the Properties of Polysaccharides from Sepia esculenta Ink: Antioxidation and Anticoagulation in Vitro.

To investigate the effect of carboxymethylation and phosphorylation modification on Sepia esculenta ink polysaccharide (SIP) properties, this study prepared carboxymethyl SIP (CSIP) with the chloracetic acid method, and phosphorylated SIP (PSIP) with the sodium trimetaphosphate (STMP)/sodium tripolyphosphate (STPP) method, on the basis of an orthogonal experiment. The in vitro antioxidant and anticoagulant activities of the derivatives were determined by assessing the scavenging capacity of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals, which activated the partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). The results showed that SIP was modified successfully to be CSIP and PSIP, and degrees of substitution (DSs) of the two products were 0.9913 and 0.0828, respectively. Phosphorylation efficiently improved the antioxidant property of SIP, and the IC50 values of PSIP on DPPH and hydroxyl radicals decreased by 63.25% and 13.77%, respectively. But carboxymethylation reduced antioxidant activity of the native polysaccharide, IC50 values of CSIP on the DPPH and hydroxyl radicals increased by 16.74% and 6.89%, respectively. SIP significantly prolonged the APTT, PT, and TT in a dose-dependent fashion, suggesting that SIP played an anticoagulant action through intrinsic, extrinsic, and common coagulation pathways. CSIP and PSIP both possessed a stronger anticoagulant capacity than SIP via the same pathways; moreover, CSIP was observed to be more effective in prolonging APTT and PT than PSIP.

Beneficial effect of Sepia esculenta ink polysaccharide on cyclophosphamide-induced immunosuppression and ovarian failure in mice.

In order to investigate prevention of squid ink polysaccharide (SIP) against cyclophosphamide (CP) induced ovarian failure and immunosuppression in mice, female Kunming mice were subjected to intraperitoneal injection of CP (120 mg/kg) and oral administration of SIP (50, 65, 80 and 110 mg/kg, continuous 14 days). At the end of the experiment, animals were sacrificed to collect sera, spleens, thymuses and ovaries for determining relative masses of organs, serum hormonal levels, contents of interleukin 2 (IL-2) and tumor necrosis factor α (TNF-α) in ovary and serum, superoxide dismutase (SOD) activity and malonaldehyde (MDA) content in ovary, contents of nuclear factor E2 related factor 2 (Nrf2) signaling pathway-related proteins in ovary, and peripheral blood populations of CD4+, CD8+ and natural killer (NK) cells. Results showed that CP induced immunosuppression in mice which was demonstrated by decreased relative masses of spleen and thymus, contents of IL-2 and TNF-α, ratio of CD4+ / CD8+, and increased population of NK cells. But the suppressive action was disinhibited by SIP. Meanwhile, CP treatment caused dysfunction of ovaries in mice that could be concluded by decreased relative mass of ovary, disruption of redox equilibrium, and modified contents of Nrf2 signaling pathway-related proteins. However, SIP exposure rescued the negative effect CP mediated in ovaries of mice. These data can be concluded that SIP protects mice from CP inducing immunosuppression and ovarian failure via Nrf2/ARE (antioxidant response element) signaling pathway.

[Analysis of arsenic speciation in Sepiae Endoconcha and research on its limit standard].

Sepiae Endoconcha is a common marine animal medicine,which generally contains high concentration of arsenic( As).The Chinese Pharmacopoeia( 2010 edition,part I) stipulated that the total As content of Sepiae Endoconcha should not exceed 2 mg·kg~(-1),while this limit was revised to 10 mg·kg~(-1) in the 2015 edition. So far,there is no research on the speciation of As in Sepiae Endoconcha,which made it hard to accurately evaluate its security risk. In this study,32 batches of Sepiae Endoconcha from different sources were collected. The safety risk assessment was carried out by determining the total As content and As speciation,inorganic As[As( Ⅲ),As( Ⅴ) ]and organic As( MMA,DMA,As C,As B) by HPLC-ICP-MS,and then the limit standard was discussed. The results showed that As B was the main form of As in Sepiae Endoconcha,followed by DMA and As( Ⅴ) ． Of the 32 batches of Sepiae Endoconcha,9 batches( accounting for 28%) were detected possessing i As. The maximum concentration of As( Ⅲ) was 103. 3 µg·kg~(-1),and the maximum concentration of As( Ⅴ) was 222. 4 µg·kg~(-1). According to the limit of i As in food,18. 75% of the samples exceeded the standard. The results indicate that there is no simple positive correlation between total As and As morphology in Sepiae Endoconcha. Besides,there is a risk in the total As limit,especially after the relaxation of the total As limit. The problem of high i As content caused by pollution and other factors is difficult to regulate. Since the toxicity of inorganic As is much higher than that of organic As,it is of great practical significance to establish inorganic As form limits in Sepiae Endoconcha.

Analysis of arsenic speciation in Sepiae Endoconcha and research on its limit standard / 中国中药杂志

Sepiae Endoconcha is a common marine animal medicine,which generally contains high concentration of arsenic( As).The Chinese Pharmacopoeia( 2010 edition,part I) stipulated that the total As content of Sepiae Endoconcha should not exceed 2 mg·kg~(-1),while this limit was revised to 10 mg·kg~(-1) in the 2015 edition. So far,there is no research on the speciation of As in Sepiae Endoconcha,which made it hard to accurately evaluate its security risk. In this study,32 batches of Sepiae Endoconcha from different sources were collected. The safety risk assessment was carried out by determining the total As content and As speciation,inorganic As[As( Ⅲ),As( Ⅴ) ]and organic As( MMA,DMA,As C,As B) by HPLC-ICP-MS,and then the limit standard was discussed. The results showed that As B was the main form of As in Sepiae Endoconcha,followed by DMA and As( Ⅴ) ． Of the 32 batches of Sepiae Endoconcha,9 batches( accounting for 28%) were detected possessing i As. The maximum concentration of As( Ⅲ) was 103. 3 μg·kg~(-1),and the maximum concentration of As( Ⅴ) was 222. 4 μg·kg~(-1). According to the limit of i As in food,18. 75% of the samples exceeded the standard. The results indicate that there is no simple positive correlation between total As and As morphology in Sepiae Endoconcha. Besides,there is a risk in the total As limit,especially after the relaxation of the total As limit. The problem of high i As content caused by pollution and other factors is difficult to regulate. Since the toxicity of inorganic As is much higher than that of organic As,it is of great practical significance to establish inorganic As form limits in Sepiae Endoconcha.

A Potential Adjuvant Agent of Chemotherapy: Sepia Ink Polysaccharides.

Sepia ink polysaccharide (SIP) isolated from squid and cuttlefish ink is a kind of acid mucopolysaccharide that has been identified in three types of primary structures from squid (Illex argentinus and Ommastrephes bartrami), cuttlefish Sepiella maindroni, and cuttlefish Sepia esculenta ink. Although SIP has been proved to be multifaceted, most of the reported evidence has illuminated its chemopreventive and antineoplastic activities. As a natural product playing a role in cancer treatment, SIP may be used as chemotherapeutic ancillary agent or functional food. Based on the current findings on SIP, we have summarized four topics in this review, including: chemopreventive, antineoplastic, chemosensitive, and procoagulant and anticoagulant activities, which are correlative closely with the actions of anticancer agents on cancer patients, such as anticancer, toxicity and thrombogenesis, with the latter two actions being common causes of death in cancer cases exposed to chemotherapeutic agents.

Toxicity, teratogenicity and antibacterial activity of posterior salivary gland (PSG) toxin from the cuttlefish Sepia pharaonis (Ehrenberg, 1831).

Toxins from the posterior salivary gland (PSG) of cuttlefishes are known toxins with pronounced toxicity. In the present study, ionic peptide rich PSG toxin from the cuttlefish S. pharaonis was isolated by ion exchange chromatography and purified by Reversed Phase High Performance Liquid Chromatography (RP-HPLC), with active fraction at a retention time of 26min. The net protein content of the PSG toxin was estimated to be 46.6mg at a proximate molecular weight of∼50kDa. Fourier Transform Infrared Spectroscopy (FT-IR) of PSG toxin revealed the presence of alcoholic OH, primary NH, alkyl CH and conjugated CONH functional groups. Circular Dichroism (CD) spectroscopy and K2D analysis of the PSG toxin confirmed the presence of secondary structure with 36.77% α-helix,12.31% ß sheet and 50.92% random coil. Scanning Electron Microscopy (SEM) of the PSG toxin eluted amberlite IRA 900 Cl- resin showed surface abrasion and corrosive blebbing. Energy Dispersive X-ray Spectrometry (EDX) analysis of PSG toxin treated resin revealed increase in nitrogen and sulphur content corresponding to amino acid composition. Teratogenicity of PSG toxin against Zebrafish embryo demonstrated developmental malformations and premature hatching at a maximum tolerated dose of 1.25µM. The PSG toxin (50µM) exhibited commendable inhibitory activity with pronounced zone of inhibition against gram E. coli (10mm) and K. pneumonia (10mm). The results strongly demonstrate the toxicity of the ionic peptide rich PSG toxin from S. pharaonis and its exploitation for its promise as a potential antibacterial agent of the future.

Neuroprotective Effect of Taurine-Rich Cuttlefish (Sepia officinalis) Extract Against Hydrogen Peroxide-Induced Oxidative Stress in SH-SY5Y Cells.

Oxidative stress mediates the cell damage in several neurodegenerative diseases, some of which are Alzheimer's disease (AD), multiple sclerosis and Parkinson's disease (PD). In this study, we investigated whether the taurine-rich cuttlefish extract could exert a protective effect on damaged human neuroblastoma SH-SY5Y cells induced by hydrogen peroxide (H2O2). Our results revealed that pre-treatment with cuttlefish extract effectively increased the cell viability by protecting the cells from intracellular reactive oxygen species (ROS) induced by H2O2 exposure. Furthermore, apoptosis related proteins Bcl-2 and Bax were investigated by western-blot analysis and results indicated that cuttlefish extract promoted the expression of anti-apoptotic Bcl-2 protein while inhibiting the expression of pro-apoptotic Bax protein. Therefore, cuttlefish extract containing the ability of scavenging excessive ROS, the capacity of anti-oxidative stress, could be employed in neurodegenerative disease prevention. In conclusion, the results suggest that cuttlefish extract could be used as a potential candidate for preventing several human neurodegenerative and other disorders caused by oxidative stress.

Melanin and Melanin-Related Polymers as Materials with Biomedical and Biotechnological Applications-Cuttlefish Ink and Mussel Foot Proteins as Inspired Biomolecules.

The huge development of bioengineering during the last years has boosted the search for new bioinspired materials, with tunable chemical, mechanical, and optoelectronic properties for the design of semiconductors, batteries, biosensors, imaging and therapy probes, adhesive hydrogels, tissue restoration, photoprotectors, etc. These new materials should complement or replace metallic or organic polymers that cause cytotoxicity and some adverse health effects. One of the most interesting biomaterials is melanin and synthetic melanin-related molecules. Melanin has a controversial molecular structure, dependent on the conditions of polymerization, and therefore tunable. It is found in animal hair and skin, although one of the common sources is cuttlefish (Sepia officinalis) ink. On the other hand, mussels synthesize adhesive proteins to anchor these marine animals to wet surfaces. Both melanin and mussel foot proteins contain a high number of catecholic residues, and their properties are related to these groups. Dopamine (DA) can easily polymerize to get polydopamine melanin (PDAM), that somehow shares properties with melanin and mussel proteins. Furthermore, PDAM can easily be conjugated with other components. This review accounts for the main aspects of melanin, as well as DA-based melanin-like materials, related to their biomedical and biotechnological applications.

As, Cd and Hg in the organs of Todarodes pacificus, Sepia longipes and Sepia madokai in the East China Sea.

Arsenic and Cadmium concentrations in Todarodes pacificus (4 males and 4 females), Sepia longipes (1 male and 3 unknown), five Sepia madokai caught in 2012 (1 male and 4 females) and five S. madokai caught in 2014 (5 females) were collected from the East China Sea (ECS) during intervals from 2010 Oct. through to 2014 Oct. The internal organs were vacuum dried and the elements were measured by ICP-MS. Among the toxic elements, As, Cd, and Hg in the digestive gland, gonads and branchial hearts of squids and cuttlefishes were measured separately. The squid T. pacificus practically inhabits offshore, whereas cuttlefishes, such as S. longipes and S. madokai, inhabit bottom coastal waters in the ECS. Cd concentration in digestive gland of T. pacificus and S. madokai is higher than similar species from other regions. This high concentration seems to be derived from anthropogenic activities and geological conditions present in the ECS. The squid and cuttlefish also accumulate high amounts of As, not only in their digestive gland but also in other organs. Arsenic could be derived from high volcanic activities. In the case of Hg, the muscles were reported to contain the highest concentration in the species studied, but unlike concentration of Cd in digestive gland, it was high compared to other studies. These elements can be utilized as indicators for environmental pollution in marine systems. For monitoring of harmful elements in squids and cuttlefish, for example Cd and As in the digestive gland and Hg in mantle should be measured.

Isolation and purification of novel peptides derived from Sepia ink: Effects on apoptosis of prostate cancer cell PC­3.

Novel prostate cancer therapeutics are in high demand. In order to identify potential therapeutic targets, protein from sepia ink was hydrolyzed by utilizing pepsin in an orthogonal array design. Pepsin hydrolysate (SH) obtained at optimal conditions exhibited the highest antitumor activity. Subsequently, a novel antitumor peptide, which was termed SHP, was isolated through ultrafiltration, gel filtration chromatography and reversed phase high­performance liquid chromatography. The amino acid sequence of SHP was identified as Leu­Lys­Glu­Glu­Asn­Arg­Arg­Arg­Arg­Asp with a molecular mass of 1371.53 Da. The results of the proliferation assay revealed that SHP significantly inhibited the proliferation of PC­3 cells in a time­ and dose­dependent manner. Acridine orange/ethidium bromide staining indicated significant SHP­induced apoptosis. Furthermore, Annexin V/PI double­staining assays revealed that the percentage of early­ stage apoptotic cells increased from 8.85 to 29% following PC­3 exposure to 5, 10 and 15 mg/ml SHP for 24 h. SHP­induced apoptosis was accompanied by the activation of cellular tumor antigen p53 and caspase­3, the upregulation of apoptosis regulator BAX, and the downregulation of apoptosis regulator Bcl­2. These findings suggest that SHP is a novel inducer of apoptosis in vitro and merits further investigation as a possible therapeutic agent for the treatment of cancer.

Nanoarchitecturing of Natural Melanin Nanospheres by Layer-by-Layer Assembly: Macroscale Anti-inflammatory Conductive Coatings with Optoelectronic Tunability.

Natural melanins are biocompatible conductors with versatile functionalities. Here, we report fabrication of multifunctional poly(vinyl alcohol)/melanin nanocomposites by layer-by-layer (LBL) assembly using melanin nanoparticles (MNPs) directly extracted from sepia officinalis inks. The LBL assembly offers facile manipulation of nanotextures as well as nm-thickness control of the macroscale film by varying solvent qualities. The time-resolved absorption was monitored during the process and quantitatively studied by fractal dimension and lacunarity analysis. The capability of nanoarchitecturing provides confirmation of complete monolayer formation and leads to tunable iridescent reflective colors of the MNP films. In addition, the MNP films have durable electrochemical conductivities as evidenced by enhanced charge storage capacities for 1000 cycles. Moreover, the MNP covered ITO (indium tin oxide) substrates significantly reduced secretion of inflammatory cytokines, TNF-α, by raw 264.7 macrophage cells compared to bare ITO, by a factor of 5 and 1.8 with and without lipopolysaccharide endotoxins, respectively. These results highlight the optoelectronic device-level tunability along with the anti-inflammatory biocompatibility of the MNP LBL film. This combination of performance should make these films particularly interesting for bioelectronic device applications such as electroceuticals, artificial bionic organs, biosensors, and implantable devices.

Sepia ink oligopeptide induces apoptosis and growth inhibition in human lung cancer cells.

Sepia ink oligopeptide (SIO), as a tripeptide extracted from Sepia ink, could be used as an inducer of apoptosis in human prostate cancer cells. We designed a cyclo-mimetic peptide of SIO by introducing a disulfide bond to stabilize the native peptide into beta turn structure, and produced a peptide with higher cell permeability and stability. Through labeling an FITC to the N-terminus of the peptide, the cell permeability was examined. Stabilized peptide showed enhanced cellular uptake than linear tripeptide as indicated by flow cytometry and cell fluorescent imaging. The high intracellular delivery of stable SIO could more efficiently inhibit cell proliferation and induce apoptosis. Furthermore, the expression of the anti-apoptotic protein Bcl-2 was down-regulated, whereas pro-apoptotic proteins P53 and caspase-3 were up-regulated by stable SIO. In conclusion, our study is the first to use stable SIO to induce apoptosis in two lung cancer cells A549 and H1299.

Inhibition of acrolein-induced autophagy and apoptosis by a glycosaminoglycan from Sepia esculenta ink in mouse Leydig cells.

In our recent reports, a squid ink polysaccharide (SIP) was found having preventive activity against cyclophosphamide induced damage in mouse testis and ovary. Here we further reveal the regulative mechanism of SIP against chemical toxicity on testis. Leydig cells exposed to acrolein (ACR) underwent apoptosis at 12h and 24h. Before apoptosis, cells occurred autophagy that was confirmed by high autophagic rate and Beclin-1 protein content at 3h. PI3K/Akt and p38 MAPK signal pathways involved in the regulatory mechanisms. These outcomes of ACR were recovered completely by SIP, which was demonstrated by attenuated disruption of redox equilibrium and increased testosterone production, through suppressing ACR-caused autophagy and apoptosis regulated by PI3K/Akt and p38 MAPK signal pathways in Leydig cells. Summarily, autophagy occurred before apoptosis caused by ACR-activated p38 MAPK and PI3K/Akt pathways were blocked by SIP, resulting in survival and functional maintenance of Leydig cells.