ABSTRACT Purpose: To explore effect and mechanism of olsalazine of Chinese generic drugs on ulcerative colitis induced by dextran sulfate sodium salt (DSS) in BALB/c mice. Methods: The mouse model of ulcerative colitis was induced by free drinking of 3% (w/v) DSS aqueous solution for seven days. The mice were treated with olsalazine (0.6 g·kg-1) of Chinese generic drugs. The therapeutic effect of olsalazine on ulcerative colitis mice was evaluated by measuring disease activity index (DAI), colonic mucosal injury index (CMDI), histopathological score (HS), and detected the expression levels of interleukin (IL)-2, IL-10, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), IL-1β in serum and IL-7, IL-17, IL-22, epidermal growth factor (EGF), transforming growth factor β1 (TGF-β1) in colonic homogenate of mice. Results: Olsalazine significantly increased the contents of IL-2, IL-10, IL-22, TGF and EGF in ulcerative colitis rats, and significantly decreased the scores of DAI, CMDI, HS and the contents in IL-7, IL-17, TNF-α, IL-1β and IFN-γ when compared with the model group. It improved the degree of colonic lesion in ulcerative colitis mice. Conclusions: It was suggested that olsalazine has a therapeutic effect on ulcerative colitis induced by DSS in mice, and the mechanism may be related to the increase of IL-2, IL-10, IL-22, TGF, and EGF and the decrease of the expression of IL-7, IL-17, TNF-α, IL-1β, and IFN-γ.

Abstract Freezing technology is currently an important preservation method for aquatic products. However, during the long-term freezing process proteins, which are the main components of muscle tissue, are inevitably exposed to an environment containing oxidative stress inducing changes in muscle protein structure. It leads to irreversible physical and chemical changes causing deterioration in the quality of aquatic products and reducing their nutritional value. Therefore, it is necessary clarify in depth to control oxidative damage of muscle during freezing and storage to gain more insight into the mechanisms of freezing-induced protein oxidation. The mechanism of protein oxidation in fish freezing, the effect of protein oxidation on fish quality, and the current regulatory methods for delaying protein oxidation were summarized in this paper review. The purpose is to provide a new research direction for the research and application of quality control in the process of fish frozen storage.

Abstract Fresh aquatic products have high nutritional value, but they are easily susceptible to spoilage. Freezing as an effective preservation method could better retain the quality and safety of aquatic products. However, mechanical damage caused by ice crystals and the oxidation of proteins and lipids would inevitably bring about a reduction in the quality of the frozen product during freezing and preservation. This work summarized the important factors that affected the quality of frozen aquatic products, revealed the mechanism of deterioration of frozen aquatic products on the quality through sensory evaluation and changes in physiochemical indicators. In the context of high-quality development, some improvements in frozen fish preservation were proposed to provide theoretical basis and solutions to improve the quality and efficiency of fish processing.