The Antioxidant Effects of Trypsin-Hydrolysate Derived from Abalone Viscera and Fishery By-Products, and the Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity of Its Purified Bioactive Peptides.

Abalone is a rich source of nutrition, the viscera of which are discarded as by-product during processing. This study explored the biological activities of peptides derived from abalone viscera (AV). Trypsin-hydrolysate of AV (TAV) was purified into three fractions using a Sephadex G-10 column. Nine bioactive peptides (VAR, NYER, LGPY, VTPGLQY, QFPVGR, LGEW, QLQFPVGR, LDW, and NLGEW) derived from TAV-F2 were sequenced. LGPY, VTPGLQY, LGEW, LDW, and NLGEW exhibited antioxidant properties, with IC50 values of 0.213, 0.297, 0.289, 0.363, and 0.303 mg/mL, respectively. In vitro analysis determined that the peptides VAR, NYER, VTPGLQY, QFPVGR, LGEW, QLQFPVGR, and NLGEW inhibited ACE, with IC50 values of 0.104, 0.107, 0.023, 0.023, 0.165, 0.004, and 0.146 mg/mL, respectively. The binding interactions of ACE-bioactive peptide complexes were investigated using docking analysis with the ZDCOK server. VTPGLQT interacted with HIS513 and TYR523, and QLQFPVGR interacted with HIS353, ALA354, GLU384, HIS513, and TYR523, contributing to the inhibition of ACE activity. They also interacted with amino acids that contribute to stability by binding to zinc ions. QFPVGR may form complexes with ACE surface sites, suggesting indirect inhibition. These results indicate that AV is a potential source of bioactive peptides with dual antioxidant and anti-hypertensive dual effects.

Antiviral Potential of Fucoxanthin, an Edible Carotenoid Purified from Sargassum siliquastrum, against Zika Virus.

Considering the lack of antiviral drugs worldwide, we investigated the antiviral potential of fucoxanthin, an edible carotenoid purified from Sargassum siliquastrum, against zika virus (ZIKV) infection. The antiviral activity of fucoxanthin was assessed in ZIKV-infected Vero E6 cells, and the relevant structural characteristics were confirmed using molecular docking and molecular dynamics (MD) simulation. Fucoxanthin decreased the infectious viral particles and nonstructural protein (NS)1 mRNA expression levels at concentrations of 12.5, 25, and 50 µM in ZIKV-infected cells. Fucoxanthin also decreased the increased mRNA levels of interferon-induced proteins with tetratricopeptide repeat 1 and 2 in ZIKV-infected cells. Molecular docking simulations revealed that fucoxanthin binds to three main ZIKV proteins, including the envelope protein, NS3, and RNA-dependent RNA polymerase (RdRp), with binding energies of -151.449, -303.478, and -290.919 kcal/mol, respectively. The complex of fucoxanthin with RdRp was more stable than RdRp protein alone based on MD simulation. Further, fucoxanthin bonded to the three proteins via repeated formation and disappearance of hydrogen bonds. Overall, fucoxanthin exerts antiviral potential against ZIKV by affecting its three main proteins in a concentration-dependent manner. Thus, fucoxanthin isolated from S. siliquastrum is a potential candidate for treating zika virus infections.

Antiviral Activity of Chlorophyll Extracts from Tetraselmis sp., a Marine Microalga, Against Zika Virus Infection.

Recent advancements in the large-scale cultivation of Tetraselmis sp. in Korea have enabled year-round production of this marine microalgae. This study explores the potential industrial applications of Tetraselmis sp. biomass by investigating the antiviral properties of its extracts and primary components. The antiviral effects of Tetraselmis sp. extracts were evaluated in Zika virus (ZIKV)-infected cells. Following extensive isolation and purification, the main compounds were characterized using liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) analyses. Their antiviral activities were confirmed using in vitro and in silico tests. Tetraselmis sp. extracts reduced infectious viral particles and non-structural protein 1 messenger RNA levels in ZIKV-infected cells without inducing cytotoxicity. Additionally, they modulated the interferon-mediated immune system responses. Tetraselmis sp. extracts are composed of four main chlorophylls: chlorophyll a, chlorin e6-131-152-dimethyl-173-phytyl ester, hydroxychlorophyll a, and hydroxypheophytin a. Among them, chlorophyll a, chlorin e6-131-152-dimethyl-173-phytyl ester, and hydroxypheophytin showed the antiviral activities in ZIKV-infected cells and molecular docking simulations predicted interactions between these chlorophylls and ZIKV. Our findings suggest that Tetraselmis sp. chlorophyll extracts exert antiviral effects against ZIKV and could serve as potential therapeutic candidates against ZIKV infection.

Mitigative Effects of PFF-A Isolated from Ecklonia cava on Pigmentation in a Zebrafish Model and Melanogenesis in B16F10 Cells.

Melanin synthesis is a defense mechanism that prevents skin damage, but excessive accumulation of melanin occurs in the skin in various reactions such as pigmentation, lentigines, and freckles. Although anti-melanogenic effects have been demonstrated for various naturally occurring marine products that inhibit and control tyrosinase activity, most studies have not been extended to in vivo applications. Phlorofucofuroeckol-A (PFF-A, 12.5-100 µM) isolated from Ecklonia cava has previously been shown to have tyrosinase-mitigative effects in B16F10 cells, but it has not been evaluated in an in vivo model, and its underlying mechanism for anti-melanogenic effects has not been studied. In the present study, we evaluated the safety and efficacy of PFF-A for anti-melanogenic effects in an in vivo model. We selected low doses of PFF-A (1.5-15 nM) and investigated their mitigative effects on pigmentation stimulated by α-MSH in vivo and their related-mechanism in an in vitro model. The findings suggest that low-dose PFF-A derived from E. cava suppresses pigmentation in vivo and melanogenesis in vitro. Therefore, this study presents the possibility that PFF-A could be utilized as a new anti-melanogenic agent in the cosmeceutical industries.

Enhanced Photoelectrochemical Water Splitting of In2S3 Photoanodes by Surface Modulation with 2D MoS2 Nanosheets.

Photoanodes with ample visible-light absorption and efficient photogenerated charge carrier dynamics expedite the actualization of high-efficiency photoelectrochemical water splitting (PEC-WS). Herein, we fabricated the heterojunction nanostructures of In2S3/MoS2 on indium-doped tin oxide glass substrates by indium sputtering and sulfurization, followed by the metal-organic chemical vapor deposition of 2D MoS2 nanosheets (NSs). The photocurrent density of In2S3/MoS2 was substantially enhanced and higher than those of pristine In2S3 and MoS2 NSs. This improvement is due to the MoS2 NSs extending the visible-light absorption range and the type-II heterojunction enhancing the separation and transfer of photogenerated electron-hole pairs. This work offers a promising avenue toward the development of an efficient photoanode for solar-driven PEC-WS.

High-Efficiency, Prevascularization-Free Macroencapsulation System for Subcutaneous Transplantation of Pancreatic Islets for Enhanced Diabetes Treatment.

Pancreatic islet macroencapsulation systems for subcutaneous transplantation have garnered significant attention as a therapy for Type I diabetes due to their minimal invasiveness and low complication rates. However, the low vascular density of subcutaneous tissue threatens the long-term survival of islets. To address this issue, prevascularized systems are introduced but various challenges remain, including system complexity and vascular-cell immunogenicity. Here, a novel prevasculature-free macroencapsulation system designed as a multilayer sheet, which ensures sufficient mass transport even in regions with sparse vasculature, is presented. Islets are localized in top/bottom micro-shell layers (≈300 µm thick) to maximize proximity to the surrounding host vasculature. These sheets, fabricated via bioprinting using rat islets and alginate-based bio-ink, double islet viability and optimize islet density, improving insulin secretion function by 240%. The subcutaneous transplantation of small islet masses (≈250 islet equivalent) into diabetic nude mice enable rapid (<1 day) recovery of blood glucose, which remain stable for >120 days. Additionally, antifibrotic drug-loaded multilayer sheets facilitate blood glucose regulation by rat islets at the subcutaneous sites of diabetic immunocompetent mice for >35 days. Thus, this macroencapsulation system can advance the treatment of Type I diabetes and is also effective for islet xenotransplantation in subcutaneous tissue.

Potential Skin Health Benefits of Abalone By-Products Suggested by Their Effects on MAPKS and PI3K/AKT/NF-kB Signaling Pathways in HDF and HaCaT Cells.

Abalone, a marine edible gastropod with nutritional value, is a popular seafood delicacy worldwide, especially in Asia; however, viscera by-products are generally discarded during processing. Therefore, we investigated the skin health benefits of abalone viscera ultrasonic extract (AVU) in human dermal fibroblasts (HDFs) and human keratinocyte (HaCaT) cells. AVU showed valuable protein contents, indicating that it is a worthy and safe material for industrial application. AVU increased collagen synthesis production and messenger RNA (mRNA) expression of Collagen Type I Alpha 1, 2, and 3 chains through the transforming growth factor beta/suppressor of mother against the decapentaplegic pathway in HDF cells. AVU also increased hyaluronic acid production, upregulated Hyaluronan Synthases 1, 2, and 3, filaggrin and aquaporin3 mRNA levels, and downregulated hyaluronidase mRNA levels in HaCaT cells. Furthermore, mechanistic studies showed that AVU increased the phosphorylation of extracellular signal-regulated kinase, p38, and cyclic AMP response-binding protein activation. AVU activated the transcription factors, phosphoinositide 3-kinase, protein kinase B, and nuclear factor kappa B cell p65 and downregulated the degranulation of inhibitory kappa B in HaCaT cells. Studies of hyaluronic acid production in AVU by inhibiting EKR, p38 and NF-κB have shown that p38 MAPK and NF-κB signaling are pivotal mechanisms, particularly in the AVU. These results demonstrated that AVU produced from by-products may improve skin health and may thus be used as a functional food and cosmetics ingredient.

Incidence of Febrile Seizures in Children with COVID-19.

The coronavirus disease 2019 (COVID-19) has become a common cause of febrile seizures (FS), especially after the Omicron surge. This study aimed to determine the incidence of COVID-19-associated FS in children. The number of confirmed COVID-19 cases in patients aged below five years residing in the Jeonbuk province from January 2020 to June 2022 was obtained from official data provided by the Ministry of Public Administration and Security. During the same period, data on FS patients with COVID-19 were obtained from all local hospitals capable of FS treatment and were analyzed retrospectively. The number of children under five years of age in Jeonbuk was 62,772, of which 33,457 (53.2%) were diagnosed with COVID-19 during the study period. Of these, 476 patients (1.4%) required hospitalization, and 64 (0.19%, 44 boys; 68.8%: 20 girls; 31.2%) developed FS. All patients with FS presented with symptoms after the Omicron surge. Before the Omicron variant, 23.4% of the patients (89 of 381) required hospitalization; however, no children with COVID-19 were hospitalized for FS. Twenty-five patients (39.1%) had complex FS while one (1.6%) presented with febrile status epilepticus. Forty-two patients (65.6%) experienced first-time FS with an average of 1.5 convulsive events.

Decellularized human pancreatic extracellular matrix-based physiomimetic microenvironment for human islet culture.

A strategy that seeks to combine the biophysical properties of inert encapsulation materials like alginate with the biochemical niche provided by pancreatic extracellular matrix (ECM)-derived biomaterials, could provide a physiomimetic pancreatic microenvironment for maintaining long-term islet viability and function in culture. Herein, we have demonstrated that incorporating human pancreatic decellularized ECM within alginate microcapsules results in a significant increase in Glucose Stimulation Index (GSI) and total insulin secreted by encapsulated human islets, compared to free islets and islets encapsulated in only alginate. ECM supplementation also resulted in long-term (58 days) maintenance of GSI levels, similar to that observed in free islets at the first time point (day 5). At early time points in culture, ECM promoted gene expression changes through ECM- and cell adhesion-mediated pathways, while it demonstrated a mitochondria-protective effect in the long-term. STATEMENT OF SIGNIFICANCE: The islet isolation process can damage the islet extracellular matrix, resulting in loss of viability and function. We have recently developed a detergent-free, DI-water based method for decellularization of human pancreas to produce a potent solubilized ECM. This ECM was added to alginate for microencapsulation of human islets, which resulted in significantly higher stimulation index and total insulin production, compared to only alginate capsules and free islets, over long-term culture. Using ECM to preserve islet health and function can improve transplantation outcomes, as well as provide novel materials and platforms for studying islet biology in microfluidic, organ-on-a-chip, bioreactor and 3D bioprinted systems.

Arsenic removal from the popular edible seaweed Sargassum fusiforme by sequential processing involving hot water, citric acid, and fermentation.

Higher quantities of arsenic (As) in Sargassum fusiforme limit its use as a food ingredient. The present study aimed to reduce As in S. fusiforme using sequential processing involving hot water, citric acid, and fermentation. The As content in S. fusiforme of 76.18 mg/kg was reduced to 30.47 mg/kg and 24.45 mg/kg using hot water and citric acid processing, respectively. However, the As content in S. fusiforme was reduced to 9.09 mg/kg by sequential processing with hot water and citric acid. Using response surface methodology, optimal processing conditions for S. fusiforme were determined to be treatment with hot water at 60 °C for 120 min followed by treatment with 0.4% citric acid. To further reduce the As content, the processed S. fusiforme was fermented by Lactobacillus rhamnosus, and the As content was further reduced to 1.64 mg/kg. In addition, the levels of organic acids and amino acids in S. fusiforme pre- and post-fermentation were significantly altered. These results indicated that the As content in S. fusiforme could be effectively reduced using the sequential processing with hot water, citric acid, and L. rhamnosus fermentation, and the organic acid and amino acid levels were significantly altered by L. rhamnosus fermentation.

Increased Incidence of Pediatric Diabetic Ketoacidosis After COVID-19: A Two-Center Retrospective Study in Korea.

PURPOSE: We evaluated the clinical characteristics and severity of diabetic ketoacidosis (DKA) in children before and after the coronavirus disease 2019 (COVID-19) outbreak to identify its indirect effects on DKA incidence. PATIENTS AND METHODS: This retrospective study included 19 children with DKA admitted to the emergency room (ER) in two centers in Jeonbuk province, Korea during the first 6 months of the year from 2017 to 2020. Data were collected on age, height, body weight, clinical symptoms, diabetic mellitus (DM) type, and laboratory findings. DKA severity was based on the presence of acute kidney injury, cerebrovascular accident, and altered mental status. The ratio of patients with DKA in all pediatric patients who visited the study ERs and in the Jeonbuk population was also determined. RESULTS: There were no differences in anthropometric characteristics and complication rates between the pre-COVID-19 and COVID-19 periods; however, the rate of polydipsia was significantly higher in the COVID-19 period. All seven patients admitted during the COVID-19 pandemic (100%) had polydipsia and polyuria and were newly diagnosed with DM. The rate of pediatric patients with DKA admitted to the ER in 2020 (0.459%) was more than twice the mean rate of 0.206% for the four-year period. The incidence of DKA in the Jeonbuk population (0.00141%) also exceeded the mean rate (0.0009%). CONCLUSION: The incidence of pediatric DKA might be higher due to the indirect effect of COVID-19 pandemic. Physicians should be aware of nonspecific symptoms related to DKA in children admitted to the ER.

Bio-inspired hollow PDMS sponge for enhanced oil-water separation.

Oil spills from disasters such as the sinking of ships and the discharge of oily wastes cause serious environmental problems. Polydimethylsiloxane(PDMS) sponges are valuable tools for isolating spilled oil. Here, we propose new PDMS sponges with bio-inspired design and enhanced absorption capacities. 3D printing was used to produce templates having negative designs, and after being filled with PDMS, the templates were selectively dissolved. Through this, PDMS sponges with well-interconnected and controlled porosities were produced within 10% error. The wettability of sponges with various pore sizes and line widths was investigated. The surfaces were found to be highly hydrophobic, with water contact angles of 100-143°, and oleophilic, with oil contact angles of ∼0°. The sponge fabricated with line width of 200 µm and pore size of 400 µm showed the highest hydrophobicity and oleophilicity. These parameters were used to produce the surfaces of hollow sponges having bio-inspired design that mimics the water absorption and storage functions of cactus. Repeated oil-water separation testing was conducted, and the absorption capacities were compared with those of non-hollow and conventional sponges. The new design showed absorption capacity up to 3.7 times that of the sponges. The bio-inspired PDMS sponge provides a significant advance in oil-water separation ability.