The Edible Seaweed Gelidium amansii Promotes Structural Plasticity of Hippocampal Neurons and Improves Scopolamine-Induced Learning and Memory Impairment in Mice.

BACKGROUND: Gelidium amansii has been gaining profound interest in East Asian countries due to its enormous commercial value for agar production and its extensive pharmacological properties. Previous studies have shown that the ethanol extract of Gelidium amansii (GAE) has promising neurotrophic effects in in vitro conditions. OBJECTIVES: The present study aimed at investigating the protective effects of GAE against scopolamine-induced cognitive deficits and its modulatory effects on hippocampal plasticity in mice. METHODS: For memory-related behavioral studies, the passive avoidance test and radial arm maze paradigm were conducted. The brain slices of the hippocampus CA1 neurons of experimental mice were then prepared to perform Golgi staining for analyzing spine density and its characteristic shape, and immunohistochemistry for assessing the expression of different pre- and postsynaptic proteins. RESULTS: Following oral administration of GAE (0.5 mg/g body weight), mice with memory deficits exhibited a significant increase in the latency time on the passive avoidance test and a decrease in the number of working and reference memory errors and latency time on the radial arm maze test. Microscopic observations of Golgi-impregnated tissue sections and immunohistochemistry of hippocampal slices showed that neurons from GAE-treated mice displayed higher spine density and spine dynamics, increased synaptic contact, and the recruitment of memory-associated proteins such as N-methyl-D-aspartate receptors (NR2A and NR2B) and postsynaptic density-95 (PSD-95) when compared with the control group. CONCLUSION: With these memory-protective functions and a modulatory role in underlying memory-related events, GAE could be a potential functional food and a promising source of pharmacological agents for the prevention and treatment of memory-related brain disorders.

The complete mitochondrial genome of Liparis ochotensis and a preliminary phylogenetic analysis.

Liparis ochotensis is a snailfish commonly confused with similar fish species because of unclear morphological characteristics. Moreover, molecular genetic studies have not been conducted for snailfish in Korea. Here, we report the complete mitogenome sequence of L. ochotensis, obtained via long PCR using universal primers for the fish mitogenome. The L. ochotensis mitogenome is 17,522 bp long, comprising 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and one control region. A neighbour-joining phylogenetic tree based on CO1 sequences depicted a close relationship with Liparis gibbus. The complete mitogenome is a valuable resource to classify and conserve L. ochotensis.

Gelidium amansii Attenuates Hypoxia/Reoxygenation-Induced Oxidative Injury in Primary Hippocampal Neurons through Suppressing GluN2B Expression.

Oxidative stress is known to be critically implicated in the pathophysiology of several neurological disorders, including Alzheimer's disease and ischemic stroke. The remarkable neurotrophic activity of Gelidium amansii, which has been reported consistently in a series of our previous studies, inspired us to investigate whether this popular agarophyte could protect against hypoxia/reoxygenation (H/R)-induced oxidative injury in hippocampal neurons. The primary culture of hippocampal neurons challenged with H/R suffered from a significant loss of cell survival, accompanied by apoptosis and necrosis, DNA damage, generation of reactive oxygen species (ROS), and dissipation of mitochondrial membrane potential (ΔΨm), which were successfully attenuated when the neuronal cultures were preconditioned with ethanolic extract of G. amansii (GAE). GAE also attenuated an H/R-mediated increase of BAX and caspase 3 expressions while promoting Bcl-2 expression. Moreover, the expression of N-methyl-d-acetate receptor subunit 2B (GluN2B), an extrasynaptic glutamate receptor, was significantly repressed, while synaptic GluN2A expression was preserved in GAE-treated neurons as compared to those without GAE intervention. Together, this study demonstrates that GAE attenuated H/R-induced oxidative injury in hippocampal neurons through, at least in part, a potential neuroprotective mechanism that involves inhibition of GluN2B-mediated excitotoxicity and suppression of ROS production, and suggests that this edible seaweed could be a potential source of bioactive metabolites with therapeutic significance against oxidative stress-related neurodegeneration, including ischemic stroke and neurodegenerative diseases.

The ethanol extract from the rhodophyta Gloiopeltis furcata and its active ingredient docosahexaenoic acid improve exercise performance in mice.

The effectiveness of natural bioresources at enhancing exercise performance is of interest to those in sports and health care. The use of 29 common seaweed species as supplements to enhance exercise performance and the recovery from physical fatigue was evaluated. The ethanol extract of the red seaweed Gloiopeltis furcata (GFE) had the greatest effect on forelimb grip strength and swimming endurance in mice. The optimal daily dose of GFE was 0.1 mg per 10 µl per g of body weight. GFE significantly increased muscle mass but had little effect on body weight and fatty deposits. The extract also significantly raised the blood superoxide dismutase and high-density lipoprotein cholesterol levels, while reducing the lactate and urea levels (p < 0.05). Docosahexaenoic acid (DHA) from GFE made the greatest contribution to improving physical exercise performance. These results support the use of GFE and DHA in health food products for enhancing physical performance. PRACTICAL APPLICATIONS: The study shows the exercise enhancement and anti-fatigue activities of GFE using the forelimb grip strength test, forced swimming endurance test, muscle mass measurement, and blood biochemical parameters. These results support the use of GFE and its active constituent DHA in functional foods or nutraceuticals for enhancing physical performance.

The hot water extract and active components nicotinamide and guanosine of the leather carp Cyprinus carpio nudis improve exercise performance in mice.

We identified the main active, exercise performance-enhancing compounds in a hot water extract of the leather carp, Cyprinus carpio nudus, as nicotinamide and guanosine. Mice were fed casein (30 mg/ml) enriched with nicotinamide (0.1 mg/ml) and guanosine (0.05 mg/ml) once daily for a week at 10 µl/g body weight. Swimming endurance (57%) and forelimb grip strength (21%) were increased significantly. The diet had little effect on body weight. After the swimming exercise, the blood glucose and superoxide dismutase levels were significantly higher (137% and 131%, respectively) than in the saline controls. The blood lactate level was 90% of that in the controls. The estimated amount of nicotinamide in the carp fillet was 26.2 mg/kg. These results suggest that the triple combination of casein with nicotinamide and guanosine improves exercise performance and delays the onset of fatigue, supporting the traditional use of carp extract in healthcare as a tonic soup. PRACTICAL APPLICATIONS: The triple-combination of casein (30 mg/ml) + nicotinamide (0.1 mg/ml) + guanosine (0.05 mg/ml) significantly enhanced the exercise performance and anti-fatigue in mice, supporting the traditional use of carp extract in healthcare as a tonic soup.

Protective effects of a mixed plant extracts derived from Astragalus membranaceus and Laminaria japonica on PTU-induced hypothyroidism and liver damages.

Protective effects of a mixed hot water extracts of Astragalus membranaceus (AWE) and Laminaria japonica (LWE), AWE: LWE 85:15 (g/g; AL mix), were investigated against propylthiouracil (PTU)-induced hypothyroidism in rats. Rats were challenged with PTU, resulting in, increased thyroid gland weight, decreased liver weight and antioxidant activities, reduced serum tri-iodothyronine and thyroxine levels with increased thyroid stimulating hormone levels, and elevated serum aspartate aminotransferase level. However, orally administered AL mix with 100, 200, and 400 mg kg-1  day-1 , significantly inhibited such abnormalities, dose-dependently. Moreover, PTU-induced abnormal histological architecture of the rat thyroid gland and liver were also significantly ameliorated by an AL mix. The results suggested that, therapeutic use of AL mix for treating hypothyroidism can be characterized by its diversified active ingredients particularly iodine and ferulic acid as confirmed by phytochemical analyses. PRACTICAL APPLICATIONS: The AL mix has synergistic effects in modulating thyroid hormone synthesis and preventing liver damages in PTU-induced hypothyroid rats. These effects of AL mix are mainly related to its richness specifically in iodine and ferulic acid. The growing interests of iodine and ferulic acid in AL mix are principally due to their beneficial effects in releasing sufficient thyroid hormones in hypothyroid conditions and promoting liver-protective functions through its antioxidant and anti-inflammatory potentials, respectively. Moreover, the results of AL mix are well-matched with the effects of standard drug levothyroxine in the present study. Therefore, appropriate dosage of AL mix will be promising as new medicinal food for preventing thyroid dysfunctions and its related liver damages.

Identification of the minimum region of flatfish myostatin propeptide (Pep45-65) for myostatin inhibition and its potential to enhance muscle growth and performance in animals.

Myostatin (MSTN) negatively regulates skeletal muscle growth, and its activity is inhibited by the binding of MSTN propeptide (MSTNpro), the N-terminal domain of proMSTN that is proteolytically cleaved from the proMSTN. Partial sequences from the N-terminal side of MSTNpro have shown to be sufficient to inhibit MSTN activity. In this study, to determine the minimum size of flatfish MSTNpro for MSTN inhibition, various truncated forms of flatfish MSTNpro with N-terminal maltose binding protein (MBP) fusion were expressed in E. coli and purified. MSTNpro regions consisting of residues 45-68, -69, and -70 with MBP fusion suppressed MSTN activity with a potency comparable to that of full-sequence flatfish MSTNpro in a pGL3-(CAGA)12-luciferase reporter assay. Even though the MSTN-inhibitory potency was about 1,000-fold lower, the flatfish MSTNpro region containing residues 45-65 (MBP-Pro45-65) showed MSTN-inhibitory capacity but not the MBP-Pro45-64, indicating that the region 45-65 is the minimum domain required for MSTN binding and suppression of its activity. To examine the in vivo effect of MBP-fused, truncated flatfish MSTNpro, MBP-Pro45-70-His6 (20 mg/kg body wt) was subcutaneously injected 5 times for 14 days in mice. Body wt gain and bone mass were not affected by the administration. Grip strength and swimming time were significantly enhanced at 7 d after the administration. At 14 d, the effect on grip strength disappeared, and the extent of the effect on swimming time significantly diminished. The presence of antibody against MBP-Pro45-70-His6 was observed at both 7 and 14 d after the administration with the titer value at 14 d being much greater than that at 7 d, suggesting that antibodies against MBP-Pro45-70-His6 neutralized the MSTN-inhibitory effect of MBP-Pro45-70-His6. We, thus, examined the MSTN-inhibitory capacity and in vivo effect of flatfish MSTNpro region 45-65 peptide (Pep45-65-NH2), which was predicted to have no immunogenicity in silico analysis. Pep45-65-NH2 suppressed MSTN activity with a potency similar to that of MBP-Pro45-65 but did not suppress GDF11, or activin A. Pep45-65-NH2 blocked MSTN-induced Smad2 phosphorylation in HepG2 cells. The administration of Pep45-65 (20 mg/kg body wt, 5 times for 2 weeks) increased the body wt gain with a greater gain at 14 d than at 7 d and muscle wt. Grip strength and swimming time were also significantly enhanced by the administration. Antibody titer against Pep45-65 was not detected. In conclusion, current results indicate that MSTN-inhibitory proteins with heterologous fusion partner may not be effective in suppressing MSTN activity in vivo due to an immune response against the proteins. Current results also show that the region of flatfish MSTNpro consisting of 45-65 (Pep45-65) can suppress mouse MSTN activity and increase muscle mass and function without invoking an immune response, implying that Pep45-65 would be a potential agent to enhance skeletal muscle growth and function in animals or to treat muscle atrophy caused by various clinical conditions.

Spinogenesis and Synaptogenesis Effects of the Red Seaweed Kappaphycus alvarezii and Its Isolated Cholesterol on Hippocampal Neuron Cultures.

Neurotrophic factors promote the formation of spines and synapses in neuron development and maintenance. Synaptic connections enhance memory in the brain. In this study, the effects of Kappaphycus alvarezii ethanolic extract (EKA) and its isolated cholesterol (iCHOL) on spinogenesis and synaptogenesis of hippocampal neurons were evaluated. Compared with the vehicle, both EKA and iCHOL significantly promoted generation of dendritic filopodia (2.4- and 2.2-fold, respectively) and spine (1.7- and 1.4-fold) formations in spinogenesis; they also increased presynaptic (3.6- and 2.6-fold), postsynaptic (2.5- and 2.9-fold), and cocolonized (3.8- and 3.0-fold) puncta, which enhances synaptic function (P< 0.05). Further, EKA- and iCHOL-treated neurons showed significantly improved functional presynaptic plasticity (1.6- and 1.4-fold, respectively, at 17 days in vitro; P<0.05). These results indicate that K. alverezii facilitates neuronal development, and support its use as a functional food to reduce neurological disorders and prevent brain aging via helping to reconstruct partially damaged neural networks.

Calotropis gigantea Promotes Neuritogenesis and Synaptogenesis through Activation of NGF-TrkA-Erk1/2 Signaling in Rat Hippocampal Neurons.

Calotropis gigantea (L.) R. Br (Apocynaceae) (commonly known as milkweed or crown flower) is a large shrub native to temperate regions of Asia, including China, Bangladesh and India and has a long history of use in traditional medicines. In this study, we investigated the neuromodulatory effects of the ethanol extracts of C. gigantea leaves (CGE) during synaptogenesis in the late stage of neuronal development and during early stage neuritogenesis in cultured rat hippocampal neurons. Maximum neuritogenic activity was achieved at a CGE concentration of 7.5 µ g/ml. At this concentration, CGE facilitated the early development of cytoarchitecture, as evidenced by increases in morphometric parameters, such as, the numbers, lengths, and number of branches of initial neurites, axon and dendrites. During the synaptogenic stage (DIV 14), immunocytochemistry (ICC) showed that CGE upregulated synaptic vesicle 2 (SV2, a marker of axon terminals) and postsynaptic density-95 (PSD-95, a postsynaptic marker) and their colocalization. CGE upregulated nerve growth factor (NGF) and activated extracellular signal-regulated kinase 1/2 (Erk1/2), which is blocked by a TrkA-specific inhibitor suggesting the neuritogenic and synaptogenic potential of CGE was due to the activation of NGF-TrkA-Erk1/2 signaling. Moreover, UPLC of CGE did not detect stigmasterol, an active component of C. gigantea. However, the chloroform-methanol and ethyl acetate subfractions of CGE exhibited initial neuritogenic activity, suggesting that multiple active components were responsible for the neurotrophic-mimetic properties of CGE. Our data prove the neuromodulatory ability of CGE and provide a means of identifying new active phytochemicals with potential nootropic, preventative or therapeutic effects on the human brain.

Neurotrophic Activity of the Carrageenophyte Kappaphycus alvarezii Cultivated at Different Depths and for Different Growth Periods in Various Areas of Indonesia.

The carrageenophyte Kappaphycus alvarezii (Rhodophyta) has neurotrophic activity in primary hippocampal neurons. This seaweed is abundant and easily cultivated in tropical coastal areas. To determine the best growth conditions for neurotrophic activity, thalli were grown at different depths and for different periods in various areas of Indonesia. Neurotrophic activity was measured based on the number of primary neurites, the total length of the primary neurites, and the length of the longest neurite. K. alvarezii had higher neurotrophic activity than carrageenophytes K. striatum and Eucheuma denticulatum cultured under the same conditions. K. alvarezii grown at the surface for 45 days had higher (1.4- to 1.8-fold) neurotrophic activity than thalli grown at depth (2 m) or harvested sooner (15 days) (P < 0.05). Relatively high activities were detected in thalli cultured at Ternate and Garut, Indonesia. Therefore, from a commercial perspective, the culture conditions at the surface for 45 days were optimal for the production of both neurotrophic compounds and carrageenan. K. alvarezii produced neurotrophic compounds under various environmental conditions, although some conditions were optimal.

Purification and cDNA cloning of the antimicrobial peptide apMolluscidin from the pen shell, Atrina pectinata.

A 5.6 kDa antimicrobial peptide (AMP) was purified from acidified gill extract of the pen shell, Atrina pectinata, by cation exchange and C18 reversed-phase high performance liquid chromatography. Comparison of the amino acid sequences and molecular weight of this peptide with those of other known AMPs revealed that it had high sequence homology with that of cgMolluscidin or hdMolluscidin; it was designated apMolluscidin. apMolluscidin comprises 59 amino acid residues containing several dibasic residue repeats and sequence repeats such as Lys-Lys and Lys-Gly. apMolluscidin exhibited potent antimicrobial activity against both Gram-positive bacteria including Bacillus subtilis (minimal effective concentration [MEC], 2.1 µg/mL), and Gram-negative bacteria including E. coli D31 (MEC, 0.5 µg/mL), without hemolytic activity. However, it did not show any activity against fungi such as Candida albicans. Secondary structure prediction suggested that it might form two helical regions and have an amphipathic structure. Full-length apMolluscidin cDNA contained 812 base pairs (bp), including a 5'-untranslated region (UTR) of 82 bp, a 3'-UTR of 547 bp, and a coding sequence of 183 bp encoding 60 amino acids (containing Met). Furthermore, qPCR analyses revealed that the mature peptide translated from apMolluscidin mRNA is expressed in a tissue-specific manner in locations such as the gill and siphon. These results indicate that apMolluscidin might be related to the innate immune defense system of abalone and may not act directly on the bacterial membrane. This is the first report of an AMP from the pen shell with a fully identified amino acid sequence.

The Red Alga Gracilariopsis chorda and Its Active Constituent Arachidonic Acid Promote Spine Dynamics via Dendritic Filopodia and Potentiate Functional Synaptic Plasticity in Hippocampal Neurons.

Exogenous neurotrophins can induce neuronal differentiation, outgrowth, survival, and synaptic function in the central nervous system. In primary cultures of rat hippocampal neurons, an ethanol extract of the red alga Gracilariopsis chorda (GCE) and its active compound arachidonic acid (AA) significantly increased the densities of dendritic filopodia and spines, promoted the expression of presynaptic vesicle protein 2 (SV2) and postsynaptic density protein 95 (PSD-95), induced robust synaptogenesis, and increased the expression of cell division control protein 42 (CDC42) and actin-related protein 2 (ARP2), which are important for actin organization in dendritic protrusions, and facilitated presynaptic plasticity by increasing the size of the synaptic vesicle pool at presynaptic nerve terminals. In addition, oral administration of GCE and AA for 10 days, at concentrations of 1 mg/g and 2.2 µg/g body weight, respectively, significantly protected against scopolamine-induced memory impairment in mice by increasing the latency time in the passive avoidance test. These results provide strong scientific evidence that these natural products can be used as neurotrophic substances and/or dietary supplements for the prevention and treatment of memory-related neurological disorders via the reconstruction of axo-dendrites and its synapses.

In vivo antioxidant activity of mackerel (Scomber japonicus) muscle protein hydrolysate.

Pacific chub mackerel (Scomber japonicus) is an important fish throughout the world, especially in East Asian countries, including Korea, China, and Japan. Protein hydrolysates from marine sources are commonly used as nutritional supplements, functional ingredients, and flavor enhancers in the food, beverage, and pharmaceutical industries. Antioxidants isolated from fish are relatively easy to prepare, are cost effective, and have no reported side effects. Hence, the present study aimed to investigate the in vivo antioxidant activities of mackerel muscle protein hydrolysate (MMPH) prepared using Protamex. The in vivo bioactivities of MMPH were investigated in alcoholic fatty liver mice (C57BL/6). Serum alanine aminotransferase and aspartate aminotransferase levels were comparable in test and control mice, whereas serum triglyceride and lipid peroxidation levels significantly (p < 0.05; p < 0.001) decreased after administration of MMPH (100-500 mg kg-1), especially at a concentration of 100 mg kg-1. A significant (p < 0.05) reduction in xanthine oxidase activity was observed in all groups treated with MMPH (100-500 mg kg-1), as compared with the control group. Significantly (p < 0.05) higher superoxide dismutase (SOD) activity/protein expression and regulated catalase (CAT) activity/protein expression levels were observed in groups administered MMPH (100-500 mg kg-1), especially at a concentration of 100 mg kg-1. These results show that the abundant amino acids of S. japonicus play an important role in the cytosol of the liver cells by directly participating in the expression of xanthine oxidase and the detoxifying SOD and CAT proteins, thereby enhancing antioxidant ability and ultimately, inhibiting lipid peroxidation. This study demonstrated that muscle protein hydrolysate from S. japonicus has strong antioxidant activities.

Anti-obesity effects of yellow catfish protein hydrolysate on mice fed a 45% kcal high-fat diet.

Obesity contributes to the etiologies of a variety of comorbid conditions, such as type 2 diabetes, hypertension and cardiovascular disease. In the present study, the anti-obesity effects of yellow catfish protein hydrolysate (YPh) were observed in mice fed a 45% kcal high-fat diet (HFD) compared with those of mice treated with simvastatin. The HFD-fed control mice exhibited noticeable increase in body weight, and whole-body and abdominal fat densities, periovarian and abdominal wall-deposited fat pad weight, as well as in the levels of triglycerides (TG), blood total cholesterol (TC), low-density lipoprotein, alanine aminotransferase, aspartate aminotransferase, creatinine, blood urea nitrogen, and in the fecal TG and TC contents. However, they exhibited a decrease in serum high-density lipoprotein levels. In addition, an increase was detected in periovarian and dorsal abdominally deposited fat pad thickness, adipocyte hypertrophy, the number of steatohepatitis regions, hepatocyte hypertrophy and lipid droplet deposition-related renal tubular vacuolation degenerative lesions, along with increased hepatic lipid peroxidation and a deteriorated endogenous antioxidant defense system (glutathione, catalase and superoxide dismutase). However, all the above-mentioned obesity-related complications were dose-dependently and significantly inhibited after 84 days of thye consecutive oral administration of 125, 250 and 500 mg/kg YPh. In addition, YPh dose-dependently depleted the liver endogenous antioxidant defense system and inhibited hepatic lipid peroxidation. Overall, the effects of 250 mg/kg YPh on HFD-induced obesity and related complications were similar or more potent than those of 10 mg/kg simvastatin. These results indicate that YPh is a promising new potent medicinal ingredient for possible use in the treatment of obesity and related complications.

Blood glycemia-modulating effects of melanian snail protein hydrolysates in mice with type II diabetes.

Freshwater animal proteins have long been used as nutrient supplements. In this study, melanian snail (Semisulcospira libertina) protein hydrolysates (MPh) were found to exert anti-diabetic and protective effects against liver and kidney damage in mice with type II diabetes adapted to a 45% kcal high-fat diet (HFD). The hypoglycemic, hepatoprotective and nephroprotective effects of MPh were analyzed after 12 weeks of the continuous oral administration of MPh at 125, 250 and 500 mg/kg. Diabetic control mice exhibited an increase in body weight, and blood glucose and insulin levels, with a decrease in serum high-density lipoprotein (HDL) levels. In addition, an increase in the regions of steatohepatitis, hepatocyte hypertrophy, and lipid droplet deposit-related renal tubular vacuolation degenerative lesions were detected, with noticeable expansion and hyperplasia of the pancreatic islets, and an increase in glucagon- and insulin-producing cells, insulin/glucagon cell ratios in the endocrine pancreas and hepatic lipid peroxidation, as well as decreased zymogen contents. Furthermore, a deterioration of the endogenous antioxidant defense system was observed, with reduced glucose utilization related hepatic glucokinase (GK) activity and an increase in hepatic gluconeogenesis-related phosphoenolpyruvate carboxykinase (PEPCK) and glucose­6-phosphatase (G6pase) activity. However, all of these diabetic complications were significantly inhibited by oral treatment with MPh in a dose-dependent manner. In addition, the marked dose-dependent inhibition of hepatic lipid peroxidation, the depletion of the liver endogenous antioxidant defense system, and changes in hepatic glucose-regulating enzyme activities were also observed. The results of this study suggest that MPh exerts potent anti-diabetic effects, along with the amelioration of related complications in mice with type II diabetes. The overall effects of MPh at a dose of 125 mg/kg on HFD-induced diabetes and related complications were similar or more potent than those of metformin (250 mg/kg).

Proteomic Analysis of the Neurotrophic Effect of Gelidium amansii in Primary Cultured Neurons.

Gelidium amansii is an edible and economically important red alga consumed in South Eastern Asia. In previous studies, we reported that the ethanol extracts of G. amansii (GAE) has promising modulatory activity with respect to the morphological and functional maturation of hippocampal neurons in culture. In this study, we show that the chloroform (CHCl3) subfraction of GAE and the ethyl acetate (EtOAc) fraction dose-dependently promoted neurite outgrowth, and their effects were comparable with that of GAE. We further assessed in cultured cortical neurons, proteins differentially expressed in the presence/absence of the GAE, CHCl3 subfraction, and the EtOAc fraction by 2D-PAGE and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Proteomic data revealed that a number of proteins responsible for multiple cellular and biochemical functions vital for neuronal development and maturation were significantly upregulated in neurons treated with the GAE, CHCl3 subfraction, and the EtOAc fraction. Of the identified proteins, profilin 2a, septin 7, cdc42, protein phosphatase 2A, DA11, eukaryotic translation initiation factor 5A-1, and γ-enolase are known to play important roles in neuritogenesis and dendritic arborization. Immunofluorescence data demonstrate that GAE-treated hippocampal neurons showed greater intensity ratios in the expressions of the septin 7 and cdc42 compared to vehicle control, validating their proteomic profiles. Together these results suggest that the GAE/CHCl3 subfraction and EtOAc fraction promote neurite development by up or downregulating several key proteins.

The Edible Red Seaweed Gracilariopsis chorda Promotes Axodendritic Architectural Complexity in Hippocampal Neurons.

The edible red seaweed Gracilariopsis chorda (Holmes) Ohmi is known for its extensive medicinal benefits and its use as a food ingredient in Korea, Japan, and China. In a previous study, an ethanol extract of G. chorda (GCE) showed potential neuroprotective effects in cultured hippocampal neurons. In this study, we further examined the ability of GCE to promote neurite extension in primary rat hippocampal neurons. Neurons were stained with the lipophilic dye DiO or immunostained to visualize the neuronal morphology. The results indicated that GCE concentration-dependently increased neurite outgrowth, with an optimal concentration of 30 µg/mL. GCE significantly promoted early neuronal differentiation (i.e., polarity and process number) and enhanced axonal and dendritic arborization in a time-responsive manner. In addition, arachidonic acid, which was previously identified and quantified as a major neuroprotective component of GCE, significantly accelerated neurite outgrowth similar to GCE. Our findings suggest that G. chorda and its active component, arachidonic acid, may be useful for developing medicinal food or pharmaceuticals in the prevention and treatment of neurological disorders.

Mussel-Inspired Anchoring of Polymer Loops That Provide Superior Surface Lubrication and Antifouling Properties.

We describe robustly anchored triblock copolymers that adopt loop conformations on surfaces and endow them with unprecedented lubricating and antifouling properties. The triblocks have two end blocks with catechol-anchoring groups and a looping poly(ethylene oxide) (PEO) midblock. The loops mediate strong steric repulsion between two mica surfaces. When sheared at constant speeds of ∼2.5 µm/s, the surfaces exhibit an extremely low friction coefficient of ∼0.002-0.004 without any signs of damage up to pressures of ∼2-3 MPa that are close to most biological bearing systems. Moreover, the polymer loops enhance inhibition of cell adhesion and proliferation compared to polymers in the random coil or brush conformations. These results demonstrate that strongly anchored polymer loops are effective for high lubrication and low cell adhesion and represent a promising candidate for the development of specialized high-performance biomedical coatings.

The Edible Red Alga Porphyra yezoensis Promotes Neuronal Survival and Cytoarchitecture in Primary Hippocampal Neurons.

The edible red alga Porphyra yezoensis is among the most popular marine algae and is of economic and medicinal importance. In the present study, the neurotrophic and neuroprotective activities of the ethanol extract of P. yezoensis (PYE) were investigated in primary cultures of hippocampal neurons. Results revealed that PYE significantly increased neurite outgrowth at an optimal concentration of 15 µg/mL. PYE dose-dependently increased viable cells, significantly accelerated the rate of neuronal differentiation in cultures, promoted axodendritic arborization, and eventually induced synaptogenesis. In addition to morphological development, PYE also promoted functional maturation as indicated by the staining of live cultures with FM 1-43. Moreover, PYE increased neuronal survivability, which was attributed to reduced apoptosis and its ROS scavenging activity. Taurine, a major organic acid in PYE (2.584/100 mg of dry PYE) promoted neurite outgrowth in a dose-dependent manner, and this promotion was suppressed by the taurine antagonist isethionic acid. The study indicates that PYE and its active component, taurine, facilitate neuronal development and maturation and have a neuroprotective effect.

Pathogenic microorganisms, heavy metals, and antibiotic residues in seven Korean freshwater aquaculture species.

This survey was performed to estimate the levels of pathogenic microorganisms, antibiotic residues, and heavy metals in seven Korean freshwater aquaculture species including Anguilla japonica, Cyprinus carpio nudus, Oncorhynchus mykiss, Pseudobagrus fulvidraco, Semisulcospira coreana, Silurus asotus, and Trionyxs sinensis. None of the ten foodborne pathogens tested in this study were found in any of the species collected from any of the aquaculture farms. Furthermore, no banned chemicals or antibiotic residues were found in any of the species collected from any of the aquaculture farms, except enrofloxacin, which was below guideline limits (0.1 mg/kg). Finally, no species had lead, cadmium, total arsenic, or total mercury concentrations above the Ministry of Food and Drug Safety (MSDF) guidelines (0.5, 0.5, 0.1, and 0.5 mg/kg, respectively). These results ensure the safety of freshwater aquaculture species and will be useful for developing consumption advisories of freshwater fishes.