Intravenous administration of multi-walled carbon nanotubes affects the formation of atherosclerosis in Sprague-Dawley rats.

BACKGROUND: Carbon nanotubes (CNTs) have many potential applications, including as delivery systems for a variety of diagnostic or therapeutic agents. However, it has been suggested that exposure to carbon nano-materials may be a risk for the development of vascular diseases due to its impact on the vascular endothelium. MATERIALS AND METHODS: Male Sprague-Dawley rats (180-200 g) were used to generate an atherosclerosis (AS) model, and the effect of intravenous administration of multi-walled carbon nanotubes (MWCNTs) on AS was studied. To further understand the underlying mechanisms, the effects of exposure of human umbilical vascular endothelial cells (HUVECs) to MWCNTs were examined. RESULTS: Exposure to 200 µg/kg MWCNTs aggravated AS in this model. In addition, exposure to 50, 100 and 200 µg/kg MWCNTs increased the calcification of the aorta in the model. Short-term exposure also revealed that 200 µg/kg MWCNTs injured the endothelium in the aorta. MWCNTs disrupted the endothelial tight junction and induced endothelial cell death. CONCLUSION: The results demonstrated that MWCNTs could induce structural and functional changes in the endothelium, probably through vascular endotheliocyte injury, which eventually affected the development of AS in SD rats.

Immunoregulatory effects of ethyl-acetate fraction of extracts from Tetrastigma hemsleyanum Diels et. Gilg on immune functions of ICR mice.

OBJECTIVE: To evaluate the effects of ethyl-acetate fraction (EAF) of extracts from Tetrastigma hemsleyanum Diels et. Gilg (TDG) on immune functions of ICR mice. METHODS: ICR mice were exposed to different doses of EAF for 15 or 30 days and then their immune functions were analyzed, including ConA-induced splenic lymphocyte transformation, SRBC-induced delayed type hypersensitivity response, serum hemolysin analysis, antibody-producing cells, peritoneal macrophage phagocytized chicken red blood cells, natural killer cell activity, and serum level of cytokines. RESULTS: EAF of extracts from TDG at different doses had various effects on immune functions of ICR mice. As compared with the controls, it increased the mouse spleen lymphocyte transformation induced by ConA, the left-hind voix pedis thickness and the number of plague forming cells (PFCs) at the dose of 1.82 mg/mL, 5.48 mg/mL, and 9.12 mg/mL, respectively; increased the ink clearance ability at the dose of 0.91 mg/mL, 1.82 mg/mL, 5.48 mg/mL, and 9.12 mg/mL, respectively; increased the phagocytosis index of mononuclear-macrophages and production of serum interferon-gamma (IFN-gamma) at the dose of 5.48 mg/mL; and could promote the production of serum tumor necrosis factor-alpha (TNF-alpha) at the dose of 9.12 mg/mL. CONCLUSION: EAF of extracts from TDG can regulate mouse immune functions in vivo.

[Evaluation of interferon-gamma producing-cells using enzyme linked immunospot assay in mice model of acute graft versus host disease].

OBJECTIVE: To investigate IFN-gamma producing-cells (IFN-gamma PCs) in allogeneic mixed lymphocyte reaction (MLR) and acute graft versus host disease (aGVHD) model of mice. METHODS: Enzyme linked immunospot assay (ELISPOT) was applied to study IFN-gamma PCs in MHC mismatched mice spleen cell MLR and aGVHD model of mice. RESULT: IFN-gamma PCs increased significantly in MLR after allogeneic mice spleen cell stimulation. In the experimental mice aGVHD model, IFN-gamma PCs were significantly higher in the severe aGVHD group than those in the moderate aGVHD. In the moderate aGVHD group, mice with GVHD prophylaxis regimen demonstrated significantly lower level of IFN-gamma PCs, compared with those without prophylaxis. IFN-gamma PCs were significantly correlated with the GVHD clinical scores in the group with moderate aGVHD and prophylaxis regimen. CONCLUSION: ELISPOT is a fast, sensitive and specific approach to evaluate alloresponse in allogeneic mice MLR and IFN-gamma PCs are correlated closely with the severity of aGVHD and prophylaxis regimen in the MHC-mismatched mice model.

Antimutagenicity of propolis against some mutagens in vivo and in vitro.

OBJECTIVE: To evaluate the antimutagenicity of propolis in vivo and in vitro. METHODS: Salmonella typhimurium strains TA98 and TA100 were used as a test model in vitro against a direct mutagen DMC and an indirect mutagen 2AF with or without S9 mix, and MN formation of mice bone marrow cell and CAs induction of mice testicle cell were applied as a test model in vivo against two mutagens CP and MMC. RESULTS: The present study clearly demonstrated that propolis could inhibit mutagenicity of both DMC and 2AF directly in a dose-dependent manner, and significant antimutagenic effects (P < 0.05) were obtained in TA98 strain at 2000 and 3000 microg/plate. It also could inhibit mutagenicity of both DMC and 2AF to TA98 strain in a dose-dependent manner, with significant antimutagenic effects (P < 0.05) appeared at 1000, 2000, and 3000 microg/plate. The results of antimutagenicity test in vivo revealed that propolis could inhibit MN formation significantly (P < 0.05) at the doses of 45.0 and 135.0 mg/kg b. w., and decrease the frequency of chromosome aberrants and chromosome aberrant cells significantly (P < 0.05) only at the dose of 135.0 mg/kg b. w. CONCLUSION: The propolis is a good inhibitor for mutagencity of DMC and 2AF in vitro, as well as for CP and MMC in vivo.