Explore the vast range of titles available.

Although space exploration has immense untapped potential, the harsh conditions of outer space pose severe threats to the physiological and mental health of astronauts. Microgravity and space radiation can have a multitude of biological effects, ranging from adverse physiological changes to alterations in gene expression. Therefore, increasing amounts of biological research are urgently needed to devise countermeasures for the astronauts during long-term space missions. In space biology research, Caenorhabditis elegans ( C. elegans ) offers several advantages over other animal models because of its small size, short lifespan, genetic traceability, and lack of ethical complications. In this review, we summarize the equipment and space research conducted thus far using C. elegans . Several biological alterations caused by environmental conditions in space have been identified, such as genomic, epigenomic, metabolic, muscular and neuromuscular, immunological, neuronal, and longevity changes, thus highlighting the applicability of C. elegans as a model organism. In addition, we explore the feasibility of integrating chemical analysis into space research, as well as incorporating biopharmaceuticals and nutraceuticals in the treatment of spaceflight-associated disorders.

Diospyros kaki (persimmon) leaves have long been utilized as traditional medicine for the treatment of ischemic stroke, angina, and hypertension and as a healthy beverage and cosmetic for anti-aging. This study aimed to isolate as many compounds as possible from an ethanol extract of the persimmon leaves to identify the biologically active compounds. The antioxidative effect of the ethyl acetate layer from the ethanol extract of the persimmon leaves was demonstrated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and online high-performance liquid chromatography-2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (HPLC-ABTS) analysis. A new flavonoid, kaempferol-3-O-β-d-2″-coumaroylgalactoside (1), and a new natural compound, kaempferol-3-O-β-d-2″-feruloylglucoside (3) were isolated from the ethyl acetate layer, along with 25 previously known compounds, including fourteen flavonoids, one ionone, two coumarins, seven triterpenoids, and one acetophenone. Their structures were determined by the interpretation of spectrometric and spectroscopic data. All isolated compounds were rapidly evaluated using an online HPLC-ABTS assay, and of these, compounds 4–8, 11, 13, 15, and 16 clearly showed antioxidative effects. The amount of these compounds was 0.3–0.65% of the extract.

The high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection threatens the effectiveness of current clinical settings. Antimicrobial photodynamic therapy (APDT) is a promising alternative to antibiotics for treating infections due to its low resistance. This study aimed to evaluate the antibacterial properties of APDT with L. fischeri extract (LFE) against MRSA and various skin and oral pathogens in vitro and its photopharmaceutical actions in Caenorhabditis elegans . The antimicrobial activities of APDT with LFE against pathogens were evaluated using plate counting method. The chemical profile was characterized using high-performance liquid chromatography and spectrophotometry. The growth rate assay, lifespan assay, and bacterial attachment on worms were performed to assess the therapeutics effects in C. elegans . The swab method was used for the detection of pathogens on the micropig skin surface. The APDT treatment with L. fischeri extract (LFE, 20 µg/mL) and red light (intensity of 120 W/m 2 ) reduced 4.3–4.9 log (colony forming unit/mL) of Staphylococcus aureus , MRSA, Cutibacterium acnes , Streptococcus mutans ; and 2.4 log (CFU/mL) of Candida albicans . Chemical analysis revealed that LFE enriched three active photosensitizers. APDT reduced bacterial populations on worms, recovered growth retardation, and improved lifespan in MRSA-infected C. elegans without causing severe side effects. The surface eradication of MRSA after exposure to LFE with red light was demonstrated on micropig skin. These findings highlight the significance of L. fischeri as a natural resource for the safe phototreatment of MRSA infection in the biomedical and cosmeceutical industries.

Screening of the antiviral and virucidal activities of ethanol extracts from plants endemic to the Republic of Korea revealed the inhibitory activity of a 70% ethanol extract of the whole plant of A. pseudoglehnii (APE) against influenza virus infection. Two chlorophyll derivatives, ethyl pheophorbides a and b, isolated as active components of APE, exerted virucidal effects with no evident cytotoxicity. These compounds were effective only under conditions of direct incubation with the virus, and exerted no effects on the influenza A virus (IAV) surface glycoproteins hemagglutinin (HA) and neuraminidase (NA). Interestingly, virucidal activities of ethyl pheophorbides a and b were observed against enveloped but not non-enveloped viruses, suggesting that these compounds act by affecting the integrity of the viral membrane and reducing infectivity.

Hepatitis C virus (HCV) is a pathogen that causes cirrhosis and hepatocellular carcinoma through chronic hepatitis C. This study focused on the anti-HCV activity of a 70% ethanol extract of Kirengeshoma koreana Nakai (KKE) and its bioactive chemical constituent(s). The KKE and its n-butanol (n-BuOH) fraction induced a significant reduction in HCV RNA levels without inducing cytotoxicity. A high-performance liquid chromatography–mass spectrometry (HPLC-MS) analysis revealed the presence of roseoside in the n-butanol fraction of the KKE, which inhibited HCV RNA replication in a concentration- and time-dependent manner without exerting cytotoxicity. Consistent with in silico molecular docking analysis data, roseoside targets and inhibits HCV NS5A/B replicase. Collectively, our findings demonstrate that roseoside is a chemical constituent in KKE that interferes with HCV replication by targeting NS5A/B replicase.

A member of the marine streptomycete clade MAR4, Streptomyces sp. CNQ-509, has genetic potential for the biosynthesis of hybrid isoprenoids and produces several meroterpenoids such as naphterpin, nitropyrrolin and marinophenazine. Our research on the strain CNQ-509 led to the isolation of two new naphterpin derivatives (1 and 2) comprised of naphthoquinone and geranyl moieties along with the known terpenoid, debromomarinone. The two-dimensional structure of these compounds was determined through spectral data analysis using data from NMR, MS and UV spectroscopy. Furthermore, the full structures of 1 and 2 including absolute configurations were unequivocally established by a combination of NMR experiments and chemical modifications.

Like other halophilic cyanobacterial genomes, the de novo -assembled genome of Euhalothece sp. Z-M001 lacks genes encoding keto-carotenoid biosynthesis enzymes, despite the presence of genes encoding carotenoid-binding proteins (CBPs). Consistent with this, HPLC analysis of carotenoids identified β-carotene and zeaxanthin as the dominant carotenoids. CBPs coexpressed with the zeaxanthin biosynthesis gene increased the survival rates of Escherichia coli strains by preventing antibiotic-induced accumulation of reactive oxygen species (ROS). RNA-seq analysis of Euhalothece revealed that among various salt resistance-related genes, those encoding the Na + transporting multiple resistance and pH adaptation (Mrp) systems, glycine betaine biosynthesis enzymes, exopolysaccharide metabolic enzymes, and CBPs were highly upregulated, suggesting their importance in hypersaline habitats. During the early phase of salt deprivation, the amounts of β-carotene and zeaxanthin showed a negative correlation with ROS content. Overall, we propose that in some halophilic cyanobacteria, β-carotene and zeaxanthin, rather than keto-carotenoids, serve as the major chromophores for CBPs, which in turn act as effective antioxidants.

Two new antibacterial phenazines were isolated from the culture broth of Brevibacterium sp. KMD 003 obtained from a marine purple vase sponge of the genus Callyspongia , collected in Kyeongpo, Gangwondo, Korea. The structures of these compounds were determined to be 6-hydroxymethyl-1-phenazine-carboxamide ( 1 ) and 1,6-phenazinedimethanol ( 2 ) through analyses of HR–EI–MS and NMR data. Compounds 1 and 2 showed antibacterial activities against Enterococcus hirae and Micrococcus luteus with 5  μ M MIC values.

Background: Osteoporosis is characterized by the microstructural depletion of bone tissue and decreased bone density, leading to an increased risk of fractures. Cotoneaster wilsonii Nakai, an endemic species of the Korean Peninsula, grows wild in Ulleungdo. In this study, we aimed to investigate the effects of C. wilsonii and its components on osteoporosis. Methods and Results: The alkaline phosphatase (ALP) activity of C. wilsonii extracts and fractions was evaluated in MC3T3-E1 pre-osteoblasts, and the n-hexane fraction (CWH) showed the best properties for ALP activity. The effects of the CWH on bone formation were assessed in MC3T3-E1 cells and ovariectomized mice. Biochemical assays and histological analyses focused on the signaling activation of osteoblast differentiation and osteogenic markers, such as ALP, collagen, and osterix. The CWH significantly activated TGF-β and Wnt signaling, enhancing osteoblast differentiation and bone matrix formation. Notably, CWH treatment improved micro-CT indices, such as femoral bone density, and restored serum osteocalcin levels compared to OVX controls. Conclusions: These results highlight the potential of the C. wilsonii Nakai n-hexane fraction as a promising therapeutic agent for managing osteoporosis.

Kaempferol, a natural flavonoid abundantly found in plants, is known to have pharmacological properties, such as anti-inflammatory and anti-cancer effects. In this study, we investigated the antiviral effects of kaempferol against a varicella-zoster virus (VZV) clinical isolate in vitro. We found that kaempferol significantly inhibited VZV replication without exhibiting cytotoxicity. Kaempferol exerted its antiviral effect at a similar stage of the VZV life cycle as acyclovir, which inhibits VZV DNA replication. Taken together, our results suggest that kaempferol inhibits VZV infection by blocking the DNA replication stage in the viral life cycle.