Effects of supplementation with higher levels of manganese and magnesium on immune function.

The magnesium (Mg) and manganese (Mn) were evaluated for its effectiveness as an immunomodulator in rats. The treatments were as follows: Group 1, AIN-93M diet (0.05% Mg, 0.001% Mn); Group 2, high-dose Mg (0.1% Mg, 0.001% Mn); and Group 3, high dose Mn (0.05% Mg, 0.01% Mn) (n-12/group). After 12 weeks of supplementation, rats were sacrificed to assess the effect on a range of innate responses (tumoricidal activity, oxidative burst and nitric oxide) and the mitogen-stimulated lymphoproliferative response. Immune function was significantly affected in both the high dose Mg and the Mn group. Lymphocyte proliferative responses and NK cell activity were measured in pooled spleen from each group. The mitogen response of lymphocytes to LPS in the spleen was significantly reduced in high dose Mg-treated groups, whereas the response to ConA was not affected in both high dose minerals-treated groups. The reactive oxygen species level of macrophages was decreased in both groups. These effects were more pronounced in high dose Mg-treated group. Nitric oxide production was also decreased in high dose minerals-treated group. In addition, tumoricidal activities of splenic NK cell and peritoneal macrophage in mineral exposed rats were significantly increased. Moreover, percent death of macrophage was reduced in two groups receiving high dose mineral supplements. Taken together, the present data suggest that high dose trace min erals exert a differential effect on the function of immune cells.

CML-1 inhibits TNF-alpha-induced NF-kappaB activation and adhesion molecule expression in endothelial cells through inhibition of IkBalpha kinase.

CML-1 is a purified extract from a mixture of 13 oriental herbs (Achyranthis Radix, Angelicae Gigantis Radix, Cinnamomi Cortex Spissus, Eucommiae Cortex, Glycyrrhizae Radix, Hoelen, Lycii Fructus, Paeoniae Radix, Rehmanniae Radix Preparata and Atractylodis Rhizoma, Zingiberis Rhizoma, Zizyphi Semen, Acori Graminei Rhizoma) that have been widely used for the treatment of inflammatory diseases in Asia. Since our previous study has been shown to have the anti-inflammatory activity of CML-1 in vivo and the upregulation of adhesion molecules in response to numerous inducing factors is associated with inflammation, this study examined the effect of CML-1 on the expression of adhesion molecules induced by TNF-alpha in cultured human umbilical vein endothelial cells (HUVECs). Preincubation of HUVECs for 20h with CML-1 (1-100mug/ml) dose-dependently inhibited TNF-alpha (10ng/ml)-induced adhesion of THP-1 monocytic cells, as well as mRNA and protein expression of E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). CML-1 was also shown to inhibit NK-kB activation induced by TNF-alpha. Furthermore, CML-1 inhibited TNF-alpha-induced IkB kinase activation, subsequent degradation of IkBalpha, and nuclear translocation of NK-kB. Evidence presented in this report demonstrated that CML-1 inhibited the adhesive capacity of HUVEC and the TNF-alpha-mediated induction of E-selectin, ICAM-1 and VCAM-1 in HUVEC by inhibiting the IkB/NF-kB signaling pathway at the level of IkB kinase, which may explain the ability of CML-1 to suppress inflammation and modulate the immune response.

Gamma-irradiation-induced intercellular adhesion molecule-1 (ICAM-1) expression is associated with catalase: activation of Ap-1 and JNK.

The ionizing radiation used in cancer therapy frequently produces damage to normal tissues and induces complex responses, including inflammation. The upregulation of the intercellular adhesion molecule-1 (ICAM-1) in response to numerous inducing factors is associated with inflammation. Therefore, this study examined the molecular mechanisms responsible for ICAM-1 expression induced by gamma-irradiation (gammaIR). ICAM-1 mRNA and cell surface expression were induced in A549 human lung epithelial cells after exposing them to gammaIR. Catalase expression and activity were also increased in gammaIR-treated cells. Treatment of the gammaIR-treated cells with catalase resulted in a significant increase in the ICAM-1 cell surface expression level. The catalase inhibitor 3-amino-1,2,4-triazole (AT) reduced the level of ICAM-1. Electrophoretic mobility shift assay (EMSA) analysis showed that activating protein 1 (AP-1) was activated by gammaIR, whereas NF-kappaB was not. Specific Jun N-terminal kinase (JNK) inhibition attenuated the upregulation of gammaIR stimulated ICAM-1. Western blot analysis revealed a marked elevation in activation of JNK. In addition, pretreatment with AT resulted in a decrease in the level of JNK phosphorylation and AP-1 activation. Overall, data suggest that induction of ICAM-1 expression by gammaIR is associated with catalase. Furthermore, catalase, JNKs, and AP-1 activation induce ICAM-1 upregulation through a sequential process.

Inhibition of ICAM-1 expression by garlic component, allicin, in gamma-irradiated human vascular endothelial cells via downregulation of the JNK signaling pathway.

Ionizing radiation used in cancer therapy frequently exerts damaging effects on normal tissues and induces a complex response including inflammation. Since the upregulation of adhesion molecules on endothelial cell surface has been known to be associated with inflammation and our previous data showed that irradiation enhanced adhesion molecules expression, interfering with the expression of adhesion molecules may be an important therapeutic target of inflammatory diseases. We examined the effect of allicin, a major component of garlic, on the induction of intercellular adhesion molecule-1 (ICAM-1) by gamma-irradiation (gamma IR) and the mechanisms of its effect in gamma-irradiated human umbilical vein endothelial cells (HUVECs). HUVECs were pretreated for 20 h with allicin (0.01-1 micro g/ml) and then exposed to 8 Gy radiation. Allicin significantly inhibited gamma IR-induced surface expression of ICAM-1 and ICAM mRNA in a dose-dependent manner. In addition, pretreatment with allicin resulted in the decrease of AP-1 activation and phosphorylation of the c-Jun NH2-terminal kinase (JNK) induced by gamma IR. These results suggest that allicin downregulates gamma IR-induced ICAM-1 expression via inhibition of both AP-1 activation and the JNK pathway and may be considered in therapeutic strategies for the management of patients treated with radiation therapy.

Immunomodulatory function of murine NK cell activity by alginate.

The in vivo immunomodulatory function of the activity of murine natural killer (NK) cells induced by high mannuronic acid-containing alginate (HMA) was examined. HMA was injected i.p at doses of 25 and 100 mg/kg. The NK activity was 3 times higher with 100 mg/kg HMA than the baseline. In addition, in vitro studies of splenocytes cultured with HMA for 20 h showed a significant increase in NK activity at E:T ratio of 100:1; a 160% and 210% increase at 10 and 100 microg/mL, respectively. There was a six fold increase in interferon-gamma production in a postculture of splenocytes with 100 microg/mL HMA. HMA had no suppressive effects on the lymphocyte function in the presence or absence of mitogens. This suggests that HMA is useful in cancer immunotherapy.

Methamphetamine administration produces immunomodulation in mice.

The abuse of methamphetamine (MA) is an increasingly growing problem globally and produces serious side effects. In the present study, the immunomodulating effects of MA were examined on the immune system after MA (5 mg/kg body weight) was administered daily orally for 14 d. The immune system was evaluated by the antibody response to sheep red blood cells (SRBC; plaque assay and serum immunoglobulin [Ig] G), natural killer (NK) activity, lymphocyte subpopulations in the spleen and thymus, and concanavalin A (Con A)- and lipopolysaccharide (LPS)-stimulated lymphocyte proliferation using splenocytes. Body weight, spleen weight, and thymus weight generally decreased in MA-treated mice. MA treatment induced an increase in the percentage of CD4(+) cells with simultaneous decrease in the percentages of CD8(+) and double-positive CD4(+)CD8(+) in thymus. MA inhibited the IgM plaque-forming cell number, and lowered the level of IgG, the proliferation of mitogen-stimulated B and T cells, and the growth of granulocyte-macrophage colony-forming units (CFU-GM). Exposure to MA also decreased interleukin-2 production by splenocytes. In contrast, splenic NK activity in exposed mice was significantly enhanced. Taken together, data indicate that the immune system was suppressed by oral MA exposure.

Vitamin C blocks TNF-alpha-induced NF-kappaB activation and ICAM-1 expression in human neuroblastoma cells.

Interactions of the cell adhesion molecules are known to play important roles in mediating inflammation. The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), activates the NF-kappaB signaling pathway, which induces the expression of various genes, such as intercellular adhesion molecule-1 (ICAM-1). In this study, the effect of vitamin C on the ICAM-1 expression induced by TNF-alpha in a human neuroblastoma cell line, SK-N-SH was investigated. Treatment with vitamin C resulted in the downregulation of the TNF-alpha-induced surface expression and ICAM-1 mRNA levels in a concentration-dependent manner. Moreover, a gel shift analysis indicated that vitamin C dose-dependently inhibited the NF-kappaB activation and IkappaBalpha degradation induced by TNF-alpha. Taken together, these results suggest that vitamin C downregulates TNF-alpha-induced ICAM-1 expression via the inhibition of NF-kappaB activation.

Modulation of murine macrophage function by methamphetamine.

The abuse of methamphetamine (MA) is an increasingly growing problem globally and produces serious side effects. In the present study, the immunomodulating effects of MA were examined on murine peritoneal macrophages after MA (5 mg/kg body weight) was administered daily orally for 2 wk. When purified macrophages were stimulated with lipopolysaccharide (LPS), the tumoricidal activity induced by LPS was significantly suppressed by MA. MA also inhibited poly I:C-induced antiviral activity in macrophages and decreased the number of peritoneal macrophages. FACS analysis showed that the expression of CD14 was markedly decreased by MA in LPS-stimulated macrophages. The production of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha: which are known to be major effector molecules in macrophage-mediated cytotoxicity, was decreased by MA. MA produced a significant effect on phagocytosis and interleukin-1 (IL-1) and IL-6 at 14 d. In addition, the level of hydrogen peroxide (H2O2) was not altered by MA. Taken together, these data indicate that MA has a differential immunomodulating effect on macrophage secretory and cellular activities.

Vitamin C blocks TNF-α-induced NF-kB activation and ICAM-1 expression in human neuroblastoma cells.

Interactions of the cell adhesion molecules are known to play important roles in mediating inflammation. The proinflammatory cytokine, tumor necrosis factor-α (TNF-α), activates the NF-kB signaling pathway, which induces the expression of various genes, such as intercellular adhesion molecule-1 (ICAM-1). In this study, the effect of vitamin C on the ICAM-1 expression induced by TNF-α in a human neuroblastoma cell line, SK-N-SH was investigated. Treatment with vitamin C resulted in the downregulation of the TNF-α-induced surface expression and ICAM-1 mRNA levels in a concentration-dependent manner. Moreover, a gel shift analysis indicated that vitamin C dose-dependently inhibited the NF-kB activation and lkBα degradation induced by TNF-α. Taken together, these results suggest that vitamin C downregulates TNF-α-induced ICAM-1 expression via the inhibition of NF-kB activation.

Antiviral and tumoricidal activities of alginate-stimulated macrophages are mediated by different mechanisms.

Macrophages play an important role in host defenses by killing tumors and virus infections and producing secretory products. High mannuronic acid (HMA) containing alginate was examined to determine the mechanisms by which HMA-activated macrophages resist infection with HSV-1 and inhibit the growth of tumor cells. The ability of macrophages to resist infection with HSV-1 or to inhibit the growth of tumor cells was assessed following treatment with HMA alginate in the presence of either antibodies to various cytokines or inhibitors/scavengers of toxic macrophage products. Only antibodies to IFN-alpha/beta were able to abrogate the protective effects of HMA alginate in macrophages infected with HSV-1, suggesting that the antiviral activity induced by this immunomodulator was mediated by the production of IFN-beta. In contrast, anti-TNF-alpha, anti-IFN and inhibitors of nitric oxide and reactive oxygen species were all able to partially abrogate HMA-induced cytostatic activity, suggesting that multiple mechanisms are involved in macrophage cytostasis. These results indicate that the HMA-induced intrinsic antiviral and extrinsic cytotoxic activites are mediated by different mechanisms.

Immune alterations in mice exposed to the herbicide simazine.

Simazine, a triazine herbicide, was investigated for its in vivo immunomodulatory properties. Male C57Bl/6 mice were treated with vehicle or 300 or 600 mg/kg body weight (bw) simazine daily orally for 4 wk. The immune system was evaluated by the antibody response to sheep red blood cells (SRBC; plaque assay and serum immunoglobulin G), natural killer (NK) and macro-phage activities, lymphocyte subpopulations in the spleen and thymus, and concanavalin A (Con A)- and lipopolysaccharide (LPS)-stimulated lymphocyte proliferation using splenocytes. Body weight and spleen and thymus weight decreased generally in simazine-treated mice, while the weight of adrenal glands was higher than in the control. Simazine treatment (600 mg/kg) induced an increase in the percentage of CD4(+) cells in spleen and CD8 + in thymus. Simazine inhibited the IgM plaque-forming cell numbers and lowered the level of IgG and the proliferation of mitogen-stimulated B cells and T cells. In addition, splenic NK and peritoneal macrophage activities in exposed mice were significantly decreased. Exposure to simazine also decreased cytokine production by macrophages, such as interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF-alpha). Taken together, data indicate that the immune system was suppressed by oral simazine exposure.

Modulation of TNF-alpha-induced ICAM-1 expression, NO and H2O2 production by alginate, allicin and ascorbic acid in human endothelial cells.

Plant nutrients are believed to provide protection against various diseases including inflammation. Since interactions of the cell adhesion molecules are known to play important roles in mediating inflammation, inhibiting adhesion protein upregulation is a possible therapeutic target. In this study, the interacellular adhesion molecule-1 (ICAM-1) was induced in human umbilical endothelial cells (HUVECs) after stimulation with TNF-alpha. In addition, alginate, ascorbic acid and allicin were demonstrated to inhibit the TNF-alpha induced expression of ICAM-1 on the HUVECs in a dose-dependent manner. These compounds also inhibited the production of NO and H2O2 induced by TNF-alpha, which suggests that the inhibition of ICAM-1 expression by the three compounds may be due to the modulated production of the reactive oxygen/nitrogen components. Overall, these results indicate that these dietary components have a therapeutic potential in the treatment of various inflammatory disorders associated with an increase in endothelial leukocyte adhesion molecules.

The immunomodulatory effects of the herbicide simazine on murine macrophage functions in vitro.

We examined the immunomodulating effects of simazine, a triazine herbicide, on murine peritoneal macrophages after in vitro pre-exposure. When thioglycollate-elicited macrophages pre-exposed to simazine were stimulated with lipopolysaccharide (LPS), the antitumor activity induced by LPS was suppressed by simazine. Simazine also inhibited poly I:C-induced antiviral activity and interferon (IFN) production in macrophages. In addition, the production of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) which have been known to be major effector molecules in macrophage-mediated cytotoxicity was decreased by simazine pretreatment in a dose-dependent manner. However, simazine had little effect on phagocytosis and the level of hydrogen peroxide (H(2)O(2)), interleukin-1 (IL-1) and IL-6 by LPS-stimulated macrophages. Taken together, these data indicate that simazine has a differential immunomodulating effect on macrophage secretory and cellular activities.