DFT-based Raman spectral study of astaxanthin geometrical isomers.

Astaxanthin is a carotenoid widely used in food additives, nutritional product and medicines, which shows many physiological functions such as antioxidant, anti-inflammatory, anti-hypertensive and anti-diabetic activities. It has been recognized that astaxanthin has all-trans and nine cis isomers, and these geometrical isomers have very different biological activities. The process of selective enrichment, metabolism and isomerization of astaxanthin in animals remains to be studied. Therefore, identifying isomers and obtaining their structural parameters are important for understanding the active mechanism of different molecular isomers. Although the traditional methods such as high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopy can be used to distinguish these isomers, these methods generally require considerable testing time, cost, sample volume, and hardly be applied in vivo. In this work, Raman spectroscopy combined with density functional theory (DFT) calculation was introduced to study different geometrical isomers of astaxanthin. The theoretical and experimental Raman spectra are in agreement, and we have demonstrated that all the known ten geometrical isomers of astaxanthin can be readily distinguished using this spectroscopic approach. The astaxanthin molecular vibrational modes, geometric structures, energies of ten geometric isomers are systematically scrutinized. Moreover, a lot of structural and Raman problems unsolved previously have been solved by the DFT-based spectral analysis. Therefore, this work provides an effective way for identification of different astaxanthin geometrical isomers, and may have important significance for promoting the research of astaxanthin isomers on biological property mechanisms and related applications in food molecular science.

Construction of an HBV DNA vaccine by fusion of the GM-CSF gene to the HBV-S gene and examination of its immune effects in normal and HBV-transgenic mice.

BACKGROUND: The hepatitis B virus (HBV) DNA vaccine can generate both HBsAg-specific humoral and cellular immune responses. The immune response can be improved by inclusion of an adjuvant, such as the cytokine GM-CSF which is known to be a very good adjuvant. METHODS: To investigate the ability of GM-CSF to enhance HBV-DNA vaccines, we constructed the plasmids by fusion of GM-CSF gene to the HBV-S gene. Normal and HBV-transgenic mice were then immunized with these plasmids. RESULTS: Our results show that pCDNA3.1-GM-CSF-S induced the most powerful HBsAg-specific humoral and cellular immune response, and that it was able to overcome the non-response to HBsAg in HBV-transgenic mice. In contrast, pCDNA3.1-S-GM-CSF was able to induce only a very poor immune response. CONCLUSIONS: When the HBV-S gene is fused to the GM-CSF gene, the immune effects of the HBV DNA vaccine both in normal and HBV-transgenic mice can be strengthened and HBV-DNA plasmids fused with GM-CSF may be useful for both preventative and therapeutic purposes.

[Antivirus effect of plasmid co expressing hepatitis B surface antigen and granulocyte macrophage-colony stimulating factor].

OBJECTIVE: To investigate whether GM-CSF can enhance the antiviral effect of HBsAg DNA vaccine. METHODS: Divided animals into 8 groups. Group A: pcDNA3.1-S 100microg; Group B: pcDNA3.1-GM-CSF-S 100microg; Group C: pcDNA3.1-S-GM-CSF 100microg; Group D: pcDNA3.1-S 50microg + pcDNA3.1-GM-CSF 50microg; Group E: pcDNA3.1-GM-CSF 100microg; Group F: recombinant HBsAg vaccine 1microg; Group G: pcDNA3.1,100microg; Group H: PBS 100microl. Serum HBsAg level and concentration of IL-2, IL-4 and IFN-gamma were examined using commercial ELISA kit. The [3H] thymidine incorporation into DNA of Spleen cells was measured; HBsAg expression of hepatocytes from HBV-transgenic mice was assessed using immunohistochemical analysis. RESULTS: Serum HBsAg level was lower and concentration of IL-2, IFN-gamma and SI was higher in mice immunized with pcDNA3.1-GM-CSF-S than those from mice immunized with pcDNA3.1-S and other groups (F=11.262, P<0.01, F=8.147, P<0.01, F=62.275, P<0.01, F=116.28, P<0.01. Less Hepatic HBsAg expression and decline of pcDNA3.1-GM-CSF-S of mice immunized with pcDNA3 were observed in comparison with control groups (F=41.439, P<0.01). Liver histological analysis showed no evidence of necrosis or inflammation in various groups. CONCLUSION: The plasmid co expressing GM-CSF and HBsAg could improve HBsAg-specific humoral and cellular immune responses induced by plasmid encoding HBsAg alone and enhance HBsAg DNA vaccine antivirus effect.

[Specific immune responses in Balb/c mice induced by plasmid coexpressing hepatitis B surface antigen and granulocyte-macrophage colony stimulating factor].

OBJECTIVES: To investigate the improvement of specific immune responses induced by plasmid coexpressing hepatitis B surface antigen (HBsAg) and granulocyte-macrophage colony stimulating factor (GM-CSF). METHODS: All Balb/c (H-2d) mice were immunized with pGM-CSF/S, pS/GM-CSF, pS or control plasmids. 4 weeks later, anti-HBs titer and the levels of IL-2, IL-4 and IFN-gamma in the supernatant of splenocytes were detected using enzyme- linked immunosorbent assay (ELISA), and HBsAg-specific cytotoxic T lymphocytes (CTL) activity was measured with a 51Cr release assay, using P815/S transfectants as target cells. RESULTS: The anti-HBs antibody titers in the serum, the levels of IL-2 and IFN-gamma, and the CTL activity in pcDNA3.1-GM-CSF-S immuned mice were higher than those in PcDNA3.1-S immunized mice (F=4.176, P<0.01; F=31.188, P<0.01; F=31.796, P<0.01; F