In vivo evidence of sea buckthorn relieving oxidative stress and improving immune performance of common carp (Cyprinus carpio L.).

BACKGROUND: Sea buckthorn has the functions of antioxidation, antitumor, anti-inflammation and regulating energy metabolism. In order to investigate the effects of sea buckthorn powder and sea buckthorn flavonoids on the antioxidant properties, immune function and muscle fatty acid composition of common carp, an oral feeding experiment was carried out. RESULTS: The administration of glucose significantly reduced the levels of glutathione and the activity of total antioxidant capacity enzyme in serum and hepatopancreas, while concurrently upregulating the level of malondialdehyde (MDA)(P < 0.05). Conversely, oral intake of sea buckthorn powder and flavonoids increased antioxidant enzyme activity and decreased MDA levels. In terms of antioxidant molecular indicators, sea buckthorn powder and sea buckthorn flavonoids significantly increased the mRNA levels of nuclear factor NF-E2-related factor (nrf2) in the hepatopancreas and muscle. Meanwhile, mRNA expression levels of downstream antioxidant-related genes (gr, cat, gpx, and sod) regulated by Nrf2 were also upregulated. In the immune aspects, the mRNA expression levels of proinflammatory cytokines, such as interleukin-6 (il-6), interleukin-1ß (il-1ß) and nuclear factor-κB (nf-κb), were reduced but the expressions of anti-inflammatory cytokines, such as growth factor-ß (tgf-ß) and interleukin-10 (il-10), were enhanced in the head kidney and spleen tissues after oral administration with sea buckthorn. In terms of muscle fatty acid composition, the ratio of n-3 polyunsaturated fatty acid (PUFA)/n-6 PUFA was notably higher after administering sea buckthorn flavonoids than that of the glucose group (P < 0.05). CONCLUSION: This study demonstrated that oral administration of sea buckthorn powder and sea buckthorn flavonoids significantly enhanced the antioxidant capacity and immune response and improved the muscle fatty acid compositions in common carp, and also mitigated the adverse effects of glucose treatment to a certain extent. © 2024 Society of Chemical Industry.

Improvement of sea buckthorn (Hippophae rhamnoides L.) flavonoids on the antioxidant and immune performance of Yellow River carp (Cyprinus carpio L.) fed high-carbohydrate diet.

High-carbohydrate (HC) diets may lead to the deterioration of the antioxidant and immune properties of Yellow River carp and the healthy development of the industry. Studies in mammals have found that sea buckthorn flavonoids (SF) improve antioxidant and immune performance. Therefore, this study comprehensively evaluated the effects of SF on Yellow River carp using in vitro and feeding trials with an HC diet. Control (C, 27.23 %), high-carbohydrate (HC, 42.99 %), and HC + SF (0.1 %, 0.2 %, and 0.4 %) groups were studied in a 10-week aquaculture experiment. The main findings were as follows: (1) SF scavenged O2·-, ·OH, and DPPH free radicals in vitro, which gradually increased with the SF concentration. (2) The antioxidant and immune performance of Yellow River carp was enhanced by dietary supplementation with SF, which involved the regulation of activities of antioxidant and immune enzymes, as well as their changes at the transcription and protein levels. In terms of antioxidant properties, compared to the HC group, HC + SF significantly decreased the activities of glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase and the contents of H2O2 and malondialdehyde in the serum and hepatopancreas. The activities of glutathione, glutathione-Px, superoxide dismutase, catalase, and total antioxidant activity in the HC-diet group. In contrast, the addition of SF increased antioxidant enzyme activity. In the hepatopancreas and muscles, SF regulated and activated Nrf2-Keap1, a key signaling pathway for oxidative stress. SF significantly increased the mRNA expression levels of downstream genes (gr, ho-1, cat, and sod) regulated by nrf2. In terms of immune performance, 0.4 % SF markedly increased the activity of immune-related enzymes. SF inhibited the gene expression of pro-inflammatory factors induced by the HC diet and promoted the gene expression of anti-inflammatory factors. In addition, the resistance of Yellow River carp to Aeromonas hydrophila was enhanced by SF. In summary, SF supplementation can reduce oxidative stress and inflammatory harm caused by the HC diet and improve the antioxidant and immune performance of Yellow River carp to varying degrees.

Engineering synthetic microbial consortium for cadaverine biosynthesis from glycerol.

OBJECTIVES: 1,5-pentanediamine (cadaverine) is a C5 platform chemical, also an important raw material for bio-polyamide PA5X. With increasing concerns about the depletion of fossil resources and global environmental protection, cadaverine bio-production has attracted more attentions. RESULTS: Here, a microbial consortium consisting of Corynebacterium glutamicum cgl-FDK and Escherichia coli BL-ABST-Spy was constructed to de novo synthesize cadaverine utilizing glycerol as the sole carbon resource. The glycerol utilization pathway was initially constructed in C. glutamicum cgl-FDK to produce lysine from glycerol. Then, the pyridoxal 5'-phosphate (PLP) biosynthesis pathway and SpyTag/SpyCatcher protein-ligation system for lysine decarboxylase (CadA) and cadaverine-lysine antiporter protein (CadB) were introduced into E. coli BL-ABST-Spy to synthesize cadaverine from lysine. Furthermore, the fermentation conditions of microbial consortium were optimized and the cadaverine production reached 9.3 g/L with glycerol as the sole carbon source. CONCLUSIONS: This work provides a promising strategy for efficiently producing cadaverine from glycerol with an artificial microbial consortium.

Effects of faba bean (Vicia faba L.) on fillet quality of Yellow River carp (Cyprinus carpio) via the oxidative stress response.

In order to further explain the fillet texture improvement of Yellow River carp (Cyprinus carpio) fed with faba bean (Vicia faba L.), a three-month rearing trial was conducted to investigate fatty acid composition, antioxidant capacity, myofiber development, collagen deposition and transcriptome in white muscle of two farmed carp groups (One was fed only faba bean, the other was fed commercial diet). As a strong oxidant, faba bean changed fatty acids composition in white muscle, especially DHA and EPA, up-regulated the levels of reactive oxygen species (ROS) and down-regulated major antioxidant enzyme activities in the hepatopancreas and white muscle. Through the analysis of transcriptome and subsequent verification analysis, we speculated that the increase of ROS led to the decrease of myofiber diameter and collagen metabolism. This study provides a theoretical basis for further understanding the regulation of faba bean on fillet texture characteristic of Yellow River carp.

The Regulatory Role of Apelin on the Appetite and Growth of Common Carp (Cyprinus Carpio L.).

Apelin, a kind of active polypeptide, has many biological functions, such as promoting food intake, enhancing immunity, and regulating energy balance. In mammals, studies have indicated that apelin is involved in regulating food intake. However, there are relatively few studies about the regulatory effect of apelin on fish feeding, and the specific mechanism is not clear. Therefore, the purpose of this study was to preliminarily investigate the regulatory effects of apelin on key genes of feeding and growth in common carp (Cyprinus Carpio L.) through in vitro and in vivo experiments. In the present study, after incubation with different concentrations of Pyr-apelin-13 (0, 10, 100, and 1000 nM) in hypothalamic fragments, the expressions of Neuropeptide Y (NPY) and Agouti related peptide (AgRP) mRNA were significantly up-regulated at 12 and 3 h, respectively, and the significant down-regulation of Cocaine and amphetamine-related transcript (CART) mRNA expression was observed at 1 and 3 h. In vivo, after Pyr-apelin-13 oral administration (0, 1, 10, and 100 pmol/g), the orexin mRNA level in the hypothalamus of common carp was significantly increased at 1, 6, and 12 h, while CART/(Proopiomelanocortin) POMC mRNA levels in the hypothalamus of common carp were significantly down-regulated. Following incubation with different concentrations of Pyr-apelin-13 (0, 10, 100, and 1000 nM) in primary hepatocytes, GHR (Growth hormone receptor), IGF2 (Insulin-like growth factor 2), IGFBP2 (Insulin like growth factor binding protein 2), and IGFBP3 (Insulin like growth factor binding protein 3) mRNA levels were significantly increased at 3 h. In vivo, the levels of IGF1 (Insulin-like growth factor 1), IGF2, IGFBP2 (Insulin like growth factor binding protein 2), and IGFBP3 mRNA were significantly increased after the oral administration of Pyr-apelin-13 in the hepatopancreas, in a time and dose-dependent manner. These results support the hypothesis that Pyr-apelin-13 might regulate the feeding and growth of common carp through mediating the expressions of appetite- and growth-related genes. Overall, apelin, which is an orexigenic peptide, improves food intake and is involved in the growth of common carp.

Mussel-inspired triblock functional protein coating with endothelial cell selectivity for endothelialization.

Surface modification of biomaterials for rapid endothelialization is a promising approach for improving long-term patency of artificial vascular grafts (e.g. polytetrafluoroethylene, PTFE) with small-caliber vascular (<6 mm). However, surfaces modified with traditional strategies using hydrophilic polymers may be excessively hydrophilic to limit endothelial cell adhesion and formation of confluent endothelial lining. In this study, a triblock functional protein cofp-MZY/R was fabricated with cell selectivity of endothelial cells (ECs) over smooth muscle cells (SMCs) for endothelialization on PTFE. This rational designed triblock protein consisted of mussel-inspired domain, zwitterionic polypeptide and bioactive peptides (YIGSR and REDV), in which Dopa was efficiently obtained with residue-specificity in vivo. The triblock protein could facilely form coating on PTFE surface and the resulting protein coating exhibited moderate nonspecific resistance of protein and platelets. Together with bioactive peptides tail, it was available for cell attachment on surfaces. As protein material, this coating displayed remarkable biocompatibility through cytotoxicity and hemolysis measurements. Moreover, cellular behavior assay demonstrated that triblock protein coating could selectively promote adhesion, proliferation and migration of ECs rather than SMCs. This mussel-inspired triblock functional protein coating indicated a promising strategy for endothelialization of artificial vascular grafts.

Engineered a novel pH-sensitive short major ampullate spidroin.

The pH diversification has been proved as an important factor affecting the self-assembly of spidroin. Herein, we constructed a novel spider silk protein (NT-MaSp1s-CT) with the pH-dependent secondary structures, containing pH-sensitive N-terminal, C-terminal domains and a repeated core region with merely 191 amino acids. Then pH sensitivity of NT-MaSp1s-CT was detected at different pH conditions and NT-MaSp1s-CT displayed pH-dependent conformational transitions consistent with rational designed objective. Besides, the micelles theory was employed to inquiry the assembly mechanism of NT-MaSp1s-CT in high concentration spinning dope. As expected, NT-MaSp1s-CT protein can be spun into continuous and uniform fibers with the pH ranging from 2 to 11, which is the largest pH boundary for artificial spider silk formation, simplifying the assembly conditions and paving a broad path for spinning process. Moreover, the hemolysis and cytotoxicity of NT-MaSp1s-CT fibers were also determined and the novel fibers exhibit excellent biocompatibility, providing wider potential applications in the biomedical and pharmaceutical fields.

Facile fabrication of a high-efficient and biocompatibility biocatalyst for bisphenol A removal.

In this study, we developed a smart microfluidic device to prepare biocatalyst HRP-pCBMA. HRP-pCBMA is composed of horseradish peroxidase (HRP) and zwitterionic polymers poly(carboxybetaine methacrylate) (pCBMA), and could be applied to biodegrade bisphenol A (BPA) efficiently. Compared to free HRP, HRP-pCBMA exhibited an obviously enhanced degrading capability for 1 mM BPA with 99.42% degradation efficiency within 20 min, even being superior to 20-fold amount of free HPR. Besides, HRP-pCBMA displayed high stability against the abrupt changes of environmental factors (temperature, pH and organic solvents), and HRP-pCBMA exhibited a relatively high BPA degradation rate of more than 90% even after 10 cycles. The Kcat and Vmax values of HRP-pCBMA were both 7-fold higher than that of free HRP, indicating significant improvement of the catalytic activity. Furthermore, the cytotoxicity assay indicated HRP-pCBMA has excellent biocompatibility. These results demonstrated that HRP-pCBMA possessed great potential in the bioremediation of BPA.

Discovery of potential antifungal triazoles: design, synthesis, biological evaluation, and preliminary antifungal mechanism exploration.

A series of triazoles as miconazole analogues was designed, synthesized and characterized by IR, NMR, MS and HRMS. All the newly prepared compounds were screened for their antifungal activities against five kinds of fungi. The bioactive assay showed that most of the synthesized compounds exhibited good or even stronger antifungal activities in comparison with the reference drugs miconazole and fluconazole. In particular, the 3,4-dichlorobenzyl derivative 5b showed a comparable or superior activity against all the tested fungal strains to standard drugs, and formed a supramolecular complex with CYP51 via the hydrogen bond between the 4-nitrogen of the triazole nucleus and the histidine residue. Preliminary experiments revealed that both of the active molecules 5b and 9c could intercalate into calf thymus DNAs, which might block DNA replication to exhibit their powerful antifungal abilities. Further studies indicated that compound 5b might be stored and transported by human serum albumin through hydrophobic interactions, specific electrostatic interactions and hydrogen bonds. These results strongly suggested that compound 5b could serve as a promising antifungal candidate.

Synthesis of novel fluconazoliums and their evaluation for antibacterial and antifungal activities.

A series of novel fluconazoliums were synthesized and their bioactive evaluation as potential antibacterial and antifungal agents were described. Some target compounds displayed good and broad-spectrum antimicrobial activities with low MIC values ranging from 0.25 to 64 µg/mL against all the tested strains, including three Gram-positive bacteria (Staphylococcus aureus, MRSA and Bacillus subtilis), three Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Bacillus proteus) as well as two fungi (Candida albicans and Aspergillus fumigatus). Among all tested title compounds, the octyl, dichlorobenzyl, naphthyl and naphthalimino derivatives gave comparable or even better antibacterial and antifungal efficiency in comparison with the reference drugs Fluconazole, Chloromycin and Norfloxacin.