Serum Metabolomics and NF-κB Pathway Analysis Revealed the Antipyretic Mechanism of Ellagic Acid on LPS-Induced Fever in Rabbits.

Fever is one of the most common clinical conditions and is characterized by pyrogenic infection, malignancy, inflammation, and tissue damage, among others. Ellagic acid (EA) can inhibit the expression of related proteins on the pathway by blocking the nuclear factor kappa-B(NF-κB) signaling pathway, inhibit the levels of pro-inflammatory factors interleukin-1ß(IL-1ß), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α), increase the level of anti-inflammatory factor IL-10, and effectively alleviate inflammatory symptoms. In addition, EA can also reduce the levels of malondialdehyde(MDA) and nitric oxide(NO) in the body, increase the activities of superoxide dismutase (SOD), glutathione (GSH), and catalase(CAT), scavenge oxidative free radicals, inhibit lipid oxidation, and achieve antipyretic and anti-inflammatory effects. The purpose of this study was to establish the relationship between EA and various inflammatory markers, such as TNF-α, IL-6, IL-1ß, prostaglandin E2(PGE2), and cyclic adenosine monophosphate(cAMP), and clarify the mechanism of the cyclooxidase-2(COX-2)/NF-κB signaling pathway. Combined with the metabolomics analysis, our study revealed the effects of EA on multiple endogenous biomarkers, reflecting the characteristics of a multi-component, multi-target, and multi-pathway mechanism. Compared to lipopolysaccharide (LPS)- treated animals, subsequent administration of EA significantly lowered the LPS-induced rectal temperature increase (p < 0.05 or p < 0.01), significantly increased serum SOD and GSH levels (p < 0.05 or p < 0.01), and significantly decreased serum MDA, IL-1ß, IL-6, and TNF-α levels (p < 0.05 or p < 0.01). In addition, compared to LPS-treated animals, subsequent administration of EA significantly decreased cerebrospinal fluid cAMP and PGE2 levels (p < 0.05 or p < 0.01), significantly decreased cAMP, significantly increased 5-HT levels (p < 0.05 or p < 0.01), and significantly down-regulated p-NF-κB p65 and COX-2 protein levels in the hypothalamus. Subsequent gas chromatography mass spectrometry(GC-MS) metabolite analysis indicated that 12 differential metabolites were detected in serum isolated 4 h after LPS treatment, and 10 differential metabolites were detected in serum collected 7 h after LPS treatment. Next, Pearson correlation analysis was used to systematically characterize the relationship between the identified metabolites and TNF-α, IL-6, MDA, SOD, PGE2, and cAMP. The levels of propionic acid, pyridine, and L-valine were up-regulated by EA, which inhibited the expression of MDA, IL-1ß, and TNF-α and increased the activity of GSH. The levels of inositol, urea, and 2-monopalmitin were down-regulated by EA, which inhibited the expression of MDA, IL-1ß, and TNF-α, increased the activity of SOD and GSH, reduced the inflammatory response, and alleviated the oxidative stress state. Combined with the results of the metabolic pathway analysis, we suggest that the pathways of the galactose metabolism, synthesis and degradation of ketone bodies, as well as ascorbic acid and aldehyde acid metabolism are closely related to the antipyretic and anti-inflammatory effects of EA. Our study established the relationship between EA and various inflammatory markers, such as TNF-α, IL-6, IL-1ß, PGE2, and cAMP, and clarified the mechanism of the COX-2/NF-κB signaling pathway. Combined with the metabolomics analysis, our study revealed the effects of EA on multiple endogenous biomarkers, reflecting the characteristics of a multi-component, multi-target, and multi-pathway mechanism.

Establishment and primary application of a mouse model with hepatitis B virus replication.

AIM: To establish a rapid and convenient animal model with hepatitis B virus (HBV) replication. METHODS: A naked DNA solution of HBV-replication-competent plasmid was transferred to BALB/C mice via the tail vein, using a hydrodynamic in vivo transfection procedure. After injection, these mice were sacrificed on d 1, 3, 4, 5, 7 and 10. HBV DNA replication intermediates in the liver were analyzed by Southern blot hybridization. The expression of hepatitis B core antigen (HBcAg) and hepatitis B surface antigen (HBsAg) in the liver was checked by immunohistochemistry. Serum HBsAg and hepatitis B e antigen (HBeAg) was detected by enzyme-linked immunosorbent assay (ELISA). Inhibition of HBV replication was compared in HBV replication model mice treated intraperitoneally with polyinosinic-polytidylin acid (polyIC) or phosphate-buffered saline (PBS). RESULTS: After hydrodynamic in vivo transfection, HBV DNA replication intermediates in the mouse liver were detectable on d 1 and abundant on d 3 and 4, the levels were slightly decreased and remained relatively stable between d 5 and 7, and were almost undetectable on d 10. The expression patterns of HBcAg and HBsAg were similar to that of HBV replication intermediate DNA, except that they reached a peak on d 1 after injection. No obvious differences in HBV DNA replication intermediates were observed in the left, right and middle lobes of the liver. After treatment with polyIC, the level of HBV intermediate DNA in the liver was lower than that in the control mice injected with PBS. CONCLUSION: A rapid and convenient mouse model with a high level of HBV replication was developed and used to investigate the inhibitory effect of polyIC on HBV replication, which provides a useful tool for future functional studies of the HBV genome.

Improved solubility and pharmacokinetics of PEGylated liposomal honokiol and human plasma protein binding ability of honokiol.

PEGylated liposomal honokiol had been developed with the purpose of improving the solubility and pharmacokinetics compared with free honokiol. Human plasma protein binding ability of honokiol was also investigated. PEGylated liposomal honokiol was prepared by thin film evaporation-sonication method. Its mean particle size was 98.68 nm, mean zeta potential was -20.6 mV and encapsulation efficiency were 87.68±1.56%. The pharmacokinetics of PEGylated liposomal honokiol was studied after intravenous administration in Balb/c mice. There were significant differences of parameters T(1/2ß) and AUC(0→∞) between them and liposome lengthened T(1/2ß) and AUC(0→∞) values. The mean T(1/2ß) value of PEGylated liposomal honokiol and free honokiol were 26.09 min and 13.46 min, respectively. The AUC(0→∞) ratio of PEGylated liposomal honokiol to free honokiol was about 1.85-fold (219.24 µg/mL min/118.68 µg/mL min) (P=0.000). Examination of protein binding ability showed that honokiol with 0.5, 8.0 and 20 µg/mL concentrations in human plasma achieved the percent of bound between 60% and 65%. The results suggested that PEGylated liposomal honokiol improved the solubility, increased the drug concentration in plasma, and withstanded the clearance. Besides, the percent of protein bound of honokiol in human plasma was between 60% and 65%.