Astaxanthin attenuates UV-irradiation aging process via activating JNK-1/DAF-16 in Caenorhabditis elegans.

Astaxanthin (AST) is a xanthophyll carotenoid with strong oxidation resistance, which can effectively scavenge various free radicals and protect organisms from oxidative damage. AST is also known to have prominent anti-aging effects, but the underlying mechanism of AST in anti-radiation aging is largely unknown. In this work, we applied ultraviolet (UV) irradiation to accelerate the aging of Caenorhabditis elegans (C. elegans) and treated the nematodes with AST to explore whether and how AST could attenuate the radiation-induced aging effect. Our results showed that AST improved the survival rate of C. elegans, reduced the aging biomarkers, and alleviated the mitochondrial dysfunction caused by the irradiation. Based on the transcriptome sequencing analysis, we identified that the key genes regulated by AST were involved in JNK-MAPK and DAF-16 longevity signaling pathways. Furthermore, we employed jnk-1 and daf-16 mutants and verified the role of the JNK-1/DAF-16 signaling pathway in the anti-aging effect. As such, this study has not only demonstrated that AST can resist the aging process caused by UV-irradiation but also revealed the anti-aging mechanism of AST through JNK-1/DAF-16 activation in C. elegans.

Exogenous arginine promotes the coproduction of biomass and astaxanthin under high-light conditions in Haematococcus pluvialis.

The economical way of Haematococcus pluvialis farming is to simultaneously achieve biomass, astaxanthin and lipid using less expensive chemicals. This paper explores the role of exogenous arginine in promoting growth and astaxanthin accumulation under stressful conditions. The application of arginine exerts a synergic effect on biomass, astaxanthin and lipid by improving carbon utilization, activating the arginine pathway and regulating carotenoid and lipid-related genes. Genes related to arginine catabolism, such as ADC, OCT, ASS1, NOS, and OAT, were up-regulated at both the cultivation and astaxanthin induction stages, signifying their importance in both growth and astaxanthin synthesis. Furthermore, transcriptome analysis revealed that arginine up-regulated transcription levels of genes involved carbon fixing, lipid biosynthesis, pyruvate metabolism, carotenoid, tricarboxylic acid cycle, and arginine and proline metabolism. The results provide a significant mechanism and applicability of using exogenous arginine and high light to stimulate bioproducts from Haematococcus pluvialis.

A crosswalk on the genetic and conventional strategies for enhancing astaxanthin production in Haematococcus pluvialis.

Astaxanthin is a naturally occurring xanthophyll with powerful: antioxidant, antitumor, and antibacterial properties that are widely employed in food, feed, medicinal and nutraceutical industries. Currently, chemical synthesis dominates the world's astaxanthin market, but the increasing demand for natural products is shifting the market for natural astaxanthin. Haematococcus pluvialis (H. pluvialis) is the factory source of natural astaxanthin when grown in optimal conditions. Currently, various strategies for the production of astaxanthin have been proposed or are being developed in order to meet its market demand. This up-to-date review scrutinized the current approaches or strategies that aim to increase astaxanthin yield from H. pluvialis. We have emphasized the genetic and environmental parameters that increase astaxanthin yield. We also looked at the transcriptomic dynamics caused by environmental factors (phytohormones induction, light, salt, temperature, and nutrient starvation) on astaxanthin synthesizing genes and other metabolic changes. Genetic engineering and culture optimization (environmental factors) are effective approaches to producing more astaxanthin for commercial purposes. Genetic engineering, in particular, is accurate, specific, potent, and safer than conventional random mutagenesis approaches. New technologies, such as CRISPR-Cas9 coupled with omics and emerging computational tools, may be the principal strategies in the future to attain strains that can produce more astaxanthin. This review provides accessible data on the strategies to increase astaxanthin accumulation natively. Also, this review can be a starting point for new scholars interested in H. pluvialis research.

Chiral Recognition of D/L-Ribose by Visual and SERS Assessments.

Ribose is the central molecular unit in ribose nucleic acid (RNA). Ribose is a key molecule in the study of many persistent scientific mysteries, such as the origin of life and the chiral homogeneity of biological molecules. Therefore, the chiral recognition of ribose is of great significance. The traditional method of chiral recognition of ribose is HPLC, which is time-consuming, expensive, and can only be operated in the laboratory. There is no report on optical analytical techniques that can quickly detect the chirality of ribose. In this study, a simple and convenient approach for the chiral recognition of ribose has been developed. ß-cyclodextrin(ß-CD)-coated Ag NPs aggregate after adding D-ribose, so that D-/L-ribose can be identified using visual colorimetry and/or surface-enhanced Raman spectroscopy (SERS). The color change visible to the naked eye can readily distinguish the chirality of ribose, while the SERS method can provide the more sensitive analysis of enantiomeric ribose. The advantages of this method are that it is fast, convenient, low cost, and can be operated outside the laboratory. DFT calculations show that D-ribose and cyclodextrin have the same chirality, forming multiple strong hydrogen bonds between them; thus, D/L-ribose will induce different optical effects.

Effective Nanocomposite Based on Bi2MoO6/MoS2/AuNRs for NIR-II Light-Boosted Photodynamic/Chemodynamic Therapy.

Bi2MoO6 (BMO) nanoparticles (NPs) have been widely used as a photocatalyst to decompose organic pollutants, but their potential for photodynamic therapy (PDT) is yet to be explored. Normally, the UV absorption property of BMO NPs is not suitable for clinical application because the penetration depth of the UV light is too small. To overcome this limitation, we rationally designed a novel nanocomposite based on Bi2MoO6/MoS2/AuNRs (BMO-MSA), which simultaneously possesses both the high photodynamic ability and POD-like activity under NIR-II light irradiation. Additionally, it has excellent photothermal stability with good photothermal conversion efficiency. The as-prepared BMO-MSA nanocomposite could induce the germline apoptosis of Caenorhabditis elegans (C. elegans) via the cep-1/p53 pathway after being illuminated by light with a wavelength of 1064 nm. The in vivo investigations confirmed the ability of the BMO-MSA nanocomposite for the induction of DNA damage in the worms, and the mechanism was approved by determining the egl-1 fold induction in the mutants that have a loss of function in the genes involved in DNA damage response mutants. Thus, this work has not only provided a novel PDT agent, which may be used for PDT in the NIR-II region, but also introduced a new approach to therapy, taking advantage of both PDT and CDT effects.

Therapeutic potential and nutritional significance of Ganoderma lucidum - a comprehensive review from 2010 to 2022.

With a long history in traditional Asian medicine, Ganoderma lucidum (G. lucidum) is a mushroom species suggested to improve health and extend life. Its medicinal reputation has merited it with numerous attributes and titles, and it is evidenced to be effective in the prevention and treatment of various metabolic disorders owing to its unique source of bioactive metabolites, primarily polysaccharides, triterpenoids, and polyphenols, attributed with antioxidant, anti-inflammatory, anticancer, hepatoprotective, antidiabetic activities, etc. These unique potential pharmaceutical properties have led to its demand as an important resource of nutrient supplements in the food industry. It is reported that the variety of therapeutic/pharmacological properties was mainly due to its extensive prebiotic and immunomodulatory functions. All literature summarized in this study was collated based on a systematic review of electronic libraries (PubMed, Scopus databases, Web of Science Core Collection, and Google Scholar) from 2010-2022. This review presents an updated and comprehensive summary of the studies on the immunomodulatory therapies and nutritional significance of G. lucidum, with the focus on recent advances in defining its immunobiological mechanisms and the possible applications in the food and pharmaceutical industries for the prevention and management of chronic diseases. In addition, toxicological evidence and the adoption of standard pharmaceutical methods for the safety assessment, quality assurance, and efficacy testing of G. lucidum-derived compounds will be the gateway to bringing them into health establishments.

Green synthesis of broccoli-derived carbon quantum dots as effective photosensitizers for the PDT effect testified in the model of mutant Caenorhabditis elegans.

The clinical application of photodynamic therapy (PDT) is still limited because of the drawbacks of the traditional photosensitizers, such as low singlet oxygen (1O2) quantum yield and the problem of photobleaching. Herein, carbon quantum dots (CQDs) derived from broccoli natural biomass as a carbon source were fabricated via a simple hydrothermal method and showed outstanding PDT ability as an effective photodynamic agent tested in Caenorhabditis elegans (C. elegans) models. The as-prepared broccoli-derived CQDs (BCQDs) showed excellent water solubility and optical properties and could generate singlet oxygen (1O2) effectively under irradiated light with a wavelength of 660 nm. The in vivo experiment revealed that the PDT efficiency of the BCQDs was dependent on the induction of germline apoptosis through the cep-1/p53 pathway. Further investigation confirmed the DNA damage of the worm by the BCQDs after sufficient light irradiation, which was tested by measuring the egl-1-fold induction in hus-1(op244), and cep-1(w40) mutants that have a loss of function in the genes involved in DNA damage response such as hus-1 (DNA checkpoint gene) and cep-1/p53 (tumor suppressor). The lack of germline apoptosis in the loss of function mutants egl-1(n487), hus-1(op244), and cep-1(w40) exposed to light irradiation compared with the control proved the necessity of these genes in DNA damage-induced germline apoptosis. Therefore, this work has not only provided a new photodynamic agent but also introduced C. elegans as an easy and high-throughput model for the rapid evaluation of the efficiency of PDT.

Facile coating of urinary catheter with bio-inspired antibacterial coating.

Formation of bacterial biofilm on indwelling urinary catheters usually causes catheter-associated urinary tract infections (CAUTIs) that represent high percent of nosocomial infections worldwide. Therefore, coating urinary catheter with antibacterial and antifouling coating using facile technique is in great demand. In this study, commercial urinary catheter was coated with a layer of the self-polymerized polydopamine which acts as active platform for the in situ formation of silver nanoparticle (AgNPs) on catheter surface. The formed coating was intensively characterized using spectroscopic and microscopic techniques. The coated catheter has the potential to release silver ion in a sustained manner with a concentration of about 2-4 µg ml-1. Disk diffusion test and colony forming unites assay verified the significant bactericidal potential of the AgNPs coated catheter against both gram-positive and gram-negative bacteria as a consequence of silver ion release. In contrast to commercial catheter, the AgNPs coated catheter prevented the adherence of bacterial cells and biofilm formation on their surfaces. Interestingly, scanning electron microscope investigations showed that AgNPs coated catheter possess greater antifouling potential against gram-positive bacteria than against gram-negative bacteria. Overall, the remarkable antibacterial and antifouling potential of the coated catheter supported the use of such facile approach for coating of different medical devices for the prevention of nosocomial infections.