The change rule of lipid oxidation and hydrolysis driven via water in Antarctic krill oil: Based on association colloid formation.

The residual water and amphiphilic compounds such as phospholipids in bulk oil can form reverse micelles, which affect oxidative stability. In this study, the Antarctic krill oil (AKO) samples with different water contents were subjected to accelerated storage. During storage, AKO exhibited oxidative changes, manifested as increased POV, TBARS values, and volatile compound levels but decreased PUFA percentages. Meanwhile, AKO underwent hydrolysis, evidenced by decreased PC, PE, and TG contents but increased FFA contents. Moreover, the degree of lipid oxidation and hydrolysis is dose-dependent with water added. Cryogenic scanning electron microscopy imaging and micelle size distribution measurement proved the presence of reverse micelle, and their size and interfacial area improved with increased water contents. Correlation analysis suggested that lipid oxidation and hydrolysis positively correlated with the size and interfacial area of reverse micelle. Therefore, it is speculated that the oil-water interface may be the site of lipid oxidation and hydrolysis.

Mechanism of discoloration of Antarctic krill oil upon storage: A study based on model systems.

The reddish-orange color of Antarctic krill oil fades during storage, and the mechanism remains unclear. Model systems containing different combinations of astaxanthin (ASTA), phosphatidylethanolamine (PE), and tocopherol were subjected to accelerated storage. Among all groups containing ASTA, only the ones with added PE showed significant fading. Meanwhile, the specific UV-visible absorption (A470 and A495) showed a similar trend. Peroxide value and thiobarbituric acid reactive substances increased during storage, while ASTA and PE contents decreased. Correlation analysis suggested that oxidized PE promoted fading by accelerating the transformation of ASTA. PE content exceeded the critical micelle concentration (1µg/g) indicating the formation of reverse micelles. Molecular docking analysis indicated that PE also interacted with ASTA in an anchor-like manner. Therefore, it is speculated that amphiphilic ASTA is more readily distributed at the oil-water interface of reverse micelles and captured by oxidized PE, which facilitates oxidation transfer, leading to ASTA oxidation and color fading.

Mechanism of color change in Antarctic krill oil during storage.

Antarctic krill oil (AKO) is reddish-orange in color but undergoes changes during storage. To investigate the color deterioration and potential mechanisms involved, the changes in color, endogenous components (astaxanthin, fatty acids, and phospholipids), and reaction products (aldehydes, α-dicarbonyl compounds, and pyrroles) of AKO upon storage were determined. Although the visual color of AKO tended to darken upon storage, the colorimetric analysis and ultraviolet-visible spectrum analysis both indicated a fading in red and yellow due to the oxidative degradation of astaxanthin. During storage of AKO, lipid oxidation led to the formation of carbonyl compounds such as aldehydes and α-dicarbonyls. In addition, phosphatidylethanolamines (PEs) exhibited a faster loss rate than phosphatidylcholines. Moreover, hydrophobic pyrroles, the Maillard-like reaction products associated with primary amine groups in PEs accumulated. Therefore, it is suggested that the Maillard-like reaction between PEs and carbonyl compounds formed by lipid oxidation contributed to color darkening of AKO during storage.

Impact of Macrophage Migration Inhibitory Factor Gene Polymorphisms and Serum Macrophage Migration Inhibitory Factor Levels on Pulmonary and Spinal Tuberculosis Susceptibility: A Pooled Analysis.

Objective: This study was designed to evaluate the association between macrophage migration inhibitory factor (MIF) gene polymorphisms, serum MIF levels and tuberculosis (TB) susceptibility. Methods: All satisfactory studies were included; the MIF genotype number and serum MIF levels were reviewed. The Stata and Review Manager software were used for the pooled analyses. Results: The pooled analyses showed that the MIF-173G/C gene polymorphism was associated with TB (allele C vs allele G: odds ratio (OR) = 1.44, 95% confidence interval (CI): 1.28-1.62, p < 0.01; genotype CC vs genotype GG: OR = 1.69, 95% CI: 1.05-2.73, p = 0.03; genotype CC+GC vs genotype GG: OR = 1.56, 95% CI: 1.34-1.81, p < 0.01; genotype GC vs genotype GG: OR = 1.50, 95% CI: 1.28-1.75, p < 0.01). The subgroup analysis showed that the MIF-173G/C gene polymorphism was significantly associated with the risk of both pulmonary tuberculosis (PTB) and spinal tuberculosis (STB).The MIF CATT-794 gene polymorphism was associated with the PTB susceptibility in Asian subjects (genotypes 5/X+6/X vs genotypes 7/X+8/X: OR = 0.39, 95% CI: 0.24-0.64, p < 0.01; genotypes 5 + 6 vs genotypes 7 + 8: OR = 0.57, 95% CI: 0.48-0.69, p < 0.01). Both PTB and STB patients had significantly elevated serum MIF levels compared to healthy controls. Conclusion: The MIF-173G/C gene polymorphism is related to both PTB and STB susceptibility in both Asian and Caucasian populations. The C allele and CC genotype of the MIF-173G/C SNP appear to be TB risk factors. The MIF CATT-794 gene polymorphism is associated with the PTB susceptibility in Asian subjects; serum MIF levels were significantly increased in PTB and STB patients.

[Effects of pricking bleeding at "Weizhong" (BL40) on sciatic nerve conduction velocity and interleukin-1alpha content in the lumbar vertebral nucleus pulposus in experimental lumbar intervertebral disc protrusion rabbits].

OBJECTIVE: To observe the effect of "Weizhong" (BL40) bleeding on sciatic nerve conduction velocity (SNCV) and interleukin-1alpha (IL-1alpha) content of the lumbar vertebral nucleus pulposus tissue in experimental lumbar intervertebral disc protrusion (LIDP) rabbits so as to explore the underlying mechanism of blood letting in the treatment of LIDP. METHODS: Forty healthy New Zealand rabbits were randomly assigned to control, model, BL40 and non-point (1 cm medial to BL40) groups, with 10 cases in each group. LIDP model was established by pushing the intervertebral disc tissue rightward to protrude the posterior longitudinal ligament with a self-made instrument after exposing the L6-7 vertebrae and intervertebral space. Blood-letting was performed at "Weizhong" (BL40) and non-point by using a triangle-edged needle to prick the local tissue, once daily and continuously for 7 days. SNCV was detected by using BL-410 physiological signal recording system, and the content of IL-1alpha in L6-7 intervertebral disc tissue determined with enzyme linked immunsorbent assay (ELISA). RESULTS: In comparison with control group and pre-modeling, SNCV decreased significantly in model, BL40 and non-acupoint groups after LIDP; while compared with model group, values of SNCV in BL40 group increased considerably (P<0.05), no significant changes were found between non-acupoint group and model group (P>0.05). Compared with control group, the contents of IL-1alpha in the nucleus pulposus in model and non-acupoint groups increased remarkably (P<0.05, 0.01), but no significant difference was found between control and BL40 groups in IL-1alpha level (P>0.05). CONCLUSION: Blood-letting at "Weizhong" (BL40) can relieve LIDP-induced nerve injury and mechanical oppression to improve SNCV, which may be closely related to its effect in decreasing inflammatory factor IL-1alpha level.