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OBJECTIVE@#To investigate whether collagen peptides can improve the immune functions of mice under the condition of simulated weightlessness.@*METHODS@#Mouse tail-suspension model was used to simulate the effects of weightlessness. Tail-suspended mice were intraperitoneally injected with 600 mg collagen peptides per kilogram body weight once a day for 10 days. Then, the mice were killed, and white blood cells were counted and classified. Lymphocyte subsets and T lymphocyte proliferations in spleens were analyzed.@*RESULTS@#Compared with normal control group, total and differential count of leukocytes, lymphocytes, T cells，CD4 and CD8 T cells, B cells and NK cells, and splenic T lymphocyte proliferation all decreased in the weightlessness simulated mice (P＜0.05). Except for NK cells, the above-mentioned parameters were increased after administration of collagen peptides, and some of the parameters were recovered to the levels of normal control mice (P＜0.05).@*CONCLUSION@#Collagen peptides can effectively improve peripheral blood lymphocyte distributions and T lymphocyte proliferations of mice under the condition of simulated weightlessness. This study nay provid the experimental basis for improvement of immune functions of astronauts.
Subject(s)
Animals , Mice , CD8-Positive T-Lymphocytes , Cell Proliferation , Collagen , Lymphocyte Count , Peptides , Spleen , Weightlessness , Weightlessness SimulationABSTRACT
ObjectiveTo study the effect of cell-mediated immune suppression effect of rocket kerosene (RK) through dermal application in mice. MethodsSkin delayed type hypersensitivity (DTH) was used to observe the relation of the RK amount the skin exposed and the cellular immune inhibitory function. Different amount of the undiluted fuel was smeared directly onto the dorsal skin of mice. Mice in negative and positive control groups were treated with acetone. After the last exposure, all the mice except those in negative control group were allergized by evenly smearing with 1% dinitrofluorobenzene (DNFB) solution on their dorsum. Five days after allergy, 1% DNFB solution was smeared onto right ear of all mice to stimulate the allergic reaction. Twenty-four hours after attack, the auricle swelling, spleen index and thymus index in corresponding mice were determined. In the first series of experiments, different dosages of RK were applied once, and the ICR mice were randomly divided into negative control group, positive control group and experimental group (0.5ml/kg.BW×1, 1ml/kg.BW×1 and 2ml/kg.BW×1 group). In the second series of experiments, the certain and same dosage of RK was applied for different times, and the ICR mice were randomly divided into negative control group, positive control group and experimental group (0.5ml/kg.BW×1, 0.5mL/kg.BW×2, 0.5ml/kg.BW×3, 0.5ml/kg.BW×4 and 0.5mL/kg.BW×5 group). In the third series of experiments, the different dosages of RK were applied more than once, and the ICR mice were randomly divided into negative control group, positive control group and experimental group (0.5ml/kg.BW×5, 1ml/kg.BW×5 and 2ml/kg.BW×5 group). Lymphocyte proliferation experiment in vitro was conducted to observe the persistent time of the cell-mediated immune suppression in mice by RK dermal exposure. The lymphocyte proliferation induced by concanavalin A (Con A) was analyzed by MTT assay, and T lymphocyte subsets (CD3+, CD4+ and CD8+) in peripheral blood and spleen lymphocyte cell cycle were analyzed by flow cytometry. ResultsRK dermal exposure (1ml/kg.BW×1) alleviated the ear edema, suppressed the spleen index elevation and thymus index reduction caused by DNFB sensitization in ICR mice, and the suppression effect increased with exposed dosage and time increasing. RK dermal exposure (1ml/kg.BW×1) suppressed ConAinduced spleen lymphocyte proliferation, and the effect persisted for 20d (P+/CD8+ ratio in peripheral blood was lower in RK group than in negative control group (P<0.05). ConclusionDermal exposure of RK may have cell-mediated immunotoxicity.
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OBJECTIVE: To evaluate the cytotoxicity of cucurbitacin B solid lipid nanoparticles (SLN) on human neuroblastoma SK-N-SH cell line in vitro. METHODS: The SK-N-SH cell line was treated with cucurbitacin B SLN at various concentrations. Growth suppression was evaluated by MTT method; apoptosis related alterations in morphology were ascertained under light microscopy. Flow cytometry (FCM) was used to investigate the distribution of cell life. RESULTS: Free cucurbitacin B and cucurbitacin B SLN inhibited the growth of SK-N-SH cells after 48 h treatment in a dose dependent manner, with IC50 values of 0.508 and 12.6 μmol · L-1, respectively. The apoptotic rates at concentrations of 0.143 and 0.716 μmol · L-1 were (34.9 ± 4.6)% and(53.6 ± 6.3)%, respectively, all of which were significantly higher than that of free cucurbitacin B (13.2 ± 2.3)% and(43.4 ± 5.5)% (P < 0.05), respectively. Under microscopy, the cells treated with free cucurbitacin B and cucurbitacin B SLN exhibited characteristics of apoptosis including decreased cell density of groups, reduced cell volume, and changed form of majority cell. Flow cytometry analysis suggested that free cucurbitacin B retarded the progression of cell cycle at G2/M and S phase, and cucurbitacin B SLN retarded the progression of cell cycle at G2/M phase. CONCLUSION: Cucurbitacin B can not only inhibit the proliferation but also induce apoptosis of human neuroblastoma SK-N-SH cell line, demonsting strong cytotoxicity. Cytotoxicity of cucurbitacin B SLN is higher than that of free cucurbitacin B.