The protective effects of Kefir extract (KE) on intestinal damage in larval zebrafish induced by Oxytetracycline: Insights into intestinal function, morphology, and molecular mechanisms.

The antibiotic oxytetracycline (OTC) can be detected in contemporary natural aquatic environments and has been implicated in causing intestinal damage in humans exposed to OTC-contaminated food or water. The irreversible damage caused by high concentrations of OTC to the intestine suggests that treatment through dietary means could still be necessary. This study proved the effectiveness of kefir extract (KE) in reversing intestinal damage caused by oxytetracycline (OTC) exposure. Following a 24-hour KE treatment subsequent to OTC exposure from 3 to 8 days post-fertilization of zebrafish larvae, molecular-level and microbiomic assessments revealed significant improvements. These included reduced expression of proinflammatory factors (IL-8 and IL-1ß), increased antioxidant levels, and reversed unhealthy distribution of intestinal microbiota. Furthermore, KE supplementation showed potential in enhancing intestinal motility in the experiment of Nile red staining and fluorescent microbead transit. However, histological analysis showed that this short-term treatment with KE only partially reversed the intestinal morphological changes induced by OTC, suggesting that a longer treatment period might be necessary for complete restoration.

A novel curdlan/methyl cellulose/walnut green husk polyphenol edible composite film for walnut packaging.

In this study, polyphenols were extracted from walnut green husk, an agricultural waste, and were incorporated into curdlan (CD) and methyl cellulose (MC) to create a novel edible composite film. For structural character, the film matrix was tightly bound primarily by non-covalent bonds and the addition of walnut green husk polyphenols (WGHP) significantly reduced the surface roughness of the composite film. For mechanical properties, the addition of WGHP improve the flexibility of films, and it significantly improved the barrier ability of ultraviolet rays and water-vapor. Furthermore, the incorporation of WGHP to the CD-MC film resulted in enhanced antioxidant and antibacterial effects, which effectively retards lipid oxidation in fried walnuts. Consequently, the fabricated CD-MC-WGHP composite film bears immense potential for use in food preservation applications, particularly in extending the shelf life of fried walnuts.

Novel antiosteoporotic peptides purified from protein hydrolysates of taihe black-boned silky fowl: By larval zebrafish model and molecular docking.

The black-boned silky fowl (BSF) muscle protein hydrolysate was gained by alcalase. The hydrolysate could stimulate MC3T3-E1 cell proliferation, as well as enhance alkaline phosphatas (ALP) activity and deposits of minerals. After isolation and purification, 55 peptide sequences with Mascot score over 40 were identified. Combined with molecular docking simulation and molecular dynamics analysis, two novel peptides (PASTGAAK and PGPPGTPF) were identified with the lowest binding energy of -4.99 kcal/mol and -3.07 kcal/mol with receptor BMPR1A of BMP-2/Smad pathway, showing the ability to increase BMPR1A stability. Moreover, both PASTGAAK and PGPPGTPF revealed strong anti-osteoporosis activities in the zebrafish model induced by dexamethasone. Additionally, the identified peptides could be beneficial for the differentiation of MC3T3-E1 cell for upregulating the expression of some osteoblast-related genes and proteins by stimulating BMP-2/Smad pathway. Overall, the two newly identified peptides could be the potential candidate to prevent osteoporosis.

The adverse effects of fluxapyroxad on the neurodevelopment of zebrafish embryos.

Fluxapyroxad (Flu), one of the succinate dehydrogenase-inhibited (SDHI) fungicides, has been extensively used in crop fungal disease control. Despite its increasing use in modern agriculture and long-term retention in the environment, the potentially toxic effects of Flu in vivo, especially on neurodevelopment, remain under-evaluated. In this study, zebrafish embryos were exposed to Flu at concentrations of 0.5, 0.75, and 1 mg/L for 96 h to evaluate the neurotoxicity of Flu. The results showed that Flu caused concentration-dependent malformations, including shorter body length, smaller head and eyes, and yolk sac edema. After exposure to Flu, larval zebrafish exhibited severe motor aberrations. Flu at a concentration of 1 mg/L significantly decreased dopamine level and notably altered acetylcholinesterase (AChE) activity and acetylcholine (ACh) content. Abnormal central nervous system (CNS) neurogenesis and disordered motor neuron development were observed in Tg (HUC-GFP) and Tg (hb9-GFP) zebrafish in Flu-treated groups. The expression of key genes involved in neurotransmission and neurodevelopment further proved that Flu impaired the zebrafish nervous system. This work contributes to our understanding of the neurotoxic effects and mechanisms induced by Flu in zebrafish and may help us take precautions against the neurotoxicity of Flu.

Effects of E-beam irradiation on the physicochemical properties of Atlantic cod (Gadus morhua).

Electron beam (E-beam) irradiation can effectively inactivate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cold-chain seafood. This study evaluated the effects of E-beam irradiation at doses killing SARS-CoV-2 on quality indicators of Atlantic cod. The cod samples were exposed to 0, 2, 4, 7, and 10 kGy E-beam irradiation, and nutrition, texture, color, and sensory attributes were investigated. The results showed that E-beam irradiation significantly increased thiobarbituric acid (TBA) value and decreased hardness, chewiness, and a* value of Atlantic cod (P < 0.05). E-beam irradiation with 10 kGy significantly lowered total volatile base nitrogen (TVB-N) and reducing sugar content while increasing moisture and ash content (P < 0.05). A significant color change was observed after irradiation with 2 kGy-7 kGy E-beam (P < 0.05). E-beam irradiation had no effects on sensory attributes (P > 0.05). A dose of 4 kGy was recommended considering the keeping quality in Atlantic cod.