Bisphenol A-induced downregulation of murine macrophage activities in vitro and ex vivo

Bisphenol A (BPA) is known to have detrimental effects on the reproductive system, but the toxicity of BPA on immune responses has not been systematically investigated. We investigated the effects of BPA exposure on the activities of murine peritoneal macrophages through evaluation of BPA-induced alteration of nitric oxide (NO) production, tumor necrosis factor-α (TNF-α) synthesis, and expression of co-stimulatory molecules B7. Macrophages were examined ex vivo from mice orally treated with various doses of BPA for 5 consecutive days per week for 4 weeks followed by culture for 2 or 4 days in the presence of lipopolysaccharides (LPS). Macrophages from naive mice were also stimulated with LPS ± BPA for 2 or 4 days. NO production was decreased with the in vitro exposure to 1, 10 and 100μM BPA. NO production was lower in the BPA-exposed mice than the control mice with all doses. In vitro, BPA suppressed TNF-α secretion with significant reduction at 10 and 100μM BPA. Similar findings were observed with the macrophages from the BPA-exposed mice. This study provides the substantial evidence on BPA-induced alteration in macrophage activity.     

Effect of endocrine disrupting chemicals on lipopolysaccharide-induced tumor necrosis factor-alpha and nitric oxide production by mouse macrophages

Little is known about the development of infectious diseases during exposure to endocrine disrupting chemicals (EDCs), although several studies have reported on the effect of EDCs on the immune function of the human body. To assess the effect of EDCs on the development of infectious disease, we investigated the effect of eighteen possible EDCs on mouse macrophage production of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) in response to bacterial endotoxin in vitro and ex vivo. Of chemicals we examined, simazine, nitrofen, and benzyl butyl phthalate inhibited lipopolysaccharide (LPS)-induced TNF-alpha production by mouse macrophage cell line RAW 264 in vitro. Carbaryl, alachlor, nonylphenol, octylphenol, tributyltin, and triphenyltin inhibited LPS-induced NO production in vitro, whereas 2,4-dichlorophenoxy acetic acid and bisphenol A enhanced its production. Zineb and alachlor, on the other hand, enhanced LPS-induced TNF-alpha production by mouse peritoneal macrophages ex vivo, while alachlor inhibited LPS/interferon-gamma-induced NO production ex vivo. These results indicate that some EDCs exert modulatory activity on endotoxin-induced macrophage activation either positively or negatively, suggesting that these compounds may affect the development of infectious diseases. This is the first report that systematically compared the effect of EDCs on LPS action.     

Induction of secretory and tumoricidal activities in peritoneal macrophages by ginsan

The immunomodulatory effect of ginsan based on the production of cytokines and the activation of macrophage was studied. Murine peritoneal macrophages (PM) on in vitro treatment with ginsan isolated from Panax ginseng induced mRNA of cytokines such as tumor necrosis factor (TNF)-alpha, interleukin-1 (IL-1)beta, interleukin-6 (IL-6) and interleukin-12 (IL-12); TNF-alpha mRNA induction was maximum within 3 h, IL-6 mRNA was gradually induced up to 24 h, and IL-1beta and IL-12 mRNA were highly induced at 24 h. IL-1beta and IL-6 protein levels also increased within 24 h in a dose-dependent manner and reached a maximum with 100 microg/ml ginsan. IL-12 was induced after 3 days and a high level of induction was detected after 4 days post treatment. Ginsan enhanced the lytic death of L929 cells through TNF-alpha activation. The mRNA expression of nitric oxide synthase (iNOS) was highly induced after 24 h treatment of ginsan, and then NO production was maximum after 48-h treatment with a low dose of 1 microg/ml. The level of iNOS mRNA induction by ginsan was slightly less than that of macrophages activating agents such as LPS plus IFN-gamma. The tumoricidal activity of macrophage cultured with ginsan on Yac-1 cells was enhanced in a dose-dependent manner; growth inhibition increased 1.6-fold with 100 microg/ml ginsan. These results suggest that ginsan exerts as an effective immunomodulator and enhances antitumor activity of macrophages.     

Enhanced macrophage antitumor effects of protein A in combination with IFN-γ

In this study we examined the potential for the synergistic augmentation of the antitumor activity of inflammatory mouse peritoneal macrophages by stimulation with protein A combined with IFN-gamma. The moderate augmentative effect induced by preincubation with protein A was demonstrated to be concentration-dependent, whereas IFN-gamma had a very low activating effect. Following preincubation with both protein A and IFN-gamma, a marked enhancement of macrophage activity was noted. In addition, based on the utilization of neutralizing antibody to TNF-alpha or the inhibition of NO production, TNF-alpha and NO were proven to be involved as mediators during the activation of tumoricidal macrophages by protein A in combination with IFN-gamma. We also demonstrated that supernatants from macrophages treated with protein A plus IFN-gamma contained both TNF-alpha and NO at markedly increased levels. Thus, tumor cell lysis in the combined system was mediated via TNF-alpha or NO. These results demonstrate the synergistic effects on mouse peritoneal macrophage function of protein A in combination with IFN-gamma and suggest that combinations of such agents may serve as the basis for future in vivo immunotherapy.     

Modulation of IFN-gamma production by TNF-alpha in macrophages from the tumor environment: significance as an angiogenic switch

BACKGROUND: The role of macrophages in tumor angiogenesis has been known to influence in the production of angiogenic cytokines and growth factors including TNF-alpha. Recently, macrophages were also found to produce INF-gamma, which were found to be involved in angiogenic inhibition. Thus, the importance of macrophages in tumor angiogenesis might be the angiogenic switch. The hypothesis tested here is that TNF-alpha can modulate the INF-gamma production in macrophages in tumor environment as part of the tumor angiogenic switch. METHODS: Macrophages in tumor environment were obtained from peritoneal cavity and s.c. grown tumor of C57BL/6 mice injected with B16F10 melanoma cell line for 6 and 11 days, respectively. Mac1+-macrophages were purified using magnetic beads (MACs; Milteny Biotech, Germany) and cultured with various concentrations of TNF-alpha at various time points at 37 degrees C. The supernatants were analyzed for IFN-gamma or VEGF by ELISA kit. RESULTS: Residential macrophages from peritoneal cavity did not respond to LPS or TNF-alpha to produce INF-gamma. However, the cells from tumor environment produced IFN-gamma as well as VEGF. Upregulation of IFN-gamma production by the addition of LPS or TNF-alpha was observed in macrophages from the tumor bearing peritoneal cavity. RT-PCR analysis revealed external TNF-alpha-induced IFN-gamma gene expression in macrophages from tumor environment. CONCLUSION: The overall data suggest that the macrophages in tumor environment might play an important role not only in angiogenic signal but also in anti-angiogenic signal by producing related cytokines. Moreover, TNF-alpha might be a key cytokine functioning as a tumor angiogenic switch.     

Stimulation of various functions in murine peritoneal macrophages by high mannuronic acid-containing alginate (HMA) exposure in vivo

High mannuronic acid-containing alginate (HMA) was tested to affect murine peritoneal macrophages. In the present study, we measured various functions of murine peritoneal macrophages that were isolated 20 h after intraperitoneal injection with HMA (25 and 100 mg/kg). HMA increased the number of peritoneal macrophages and phagocytosis. Macrophages from HMA-treated mice significantly inhibited growth of tumor cells compared to macrophages from control mice. In addition, supernatants from macrophages of HMA-treated mice contained nitric oxide (NO), hydrogen peroxide (H2O2) and TNF-alpha. The increased production of these cytotoxic molecules induced by HMA is consistent with tumoricidal activity of activated macrophages. Furthermore, HMA-induced tumoricidal activity was partially abrogated by anti-TNF-alpha, inhibitors of NO and the scavenger of reactive oxygen. Thus, the tumoricidal activity induced by HMA appeared to be mediated by the production of TNF-alpha, NO and H2O2. Taken together, these results suggest that HMA has the immunostimulating effect on macrophages after in vivo exposure of it.     

灵芝多糖肽对小鼠腹腔巨噬细胞一氧化氮产生的影响

目的　研究灵芝多糖肽 (GLPP)对小鼠腹腔巨噬细胞一氧化氮产生的影响并探讨其作用机制。方法　以Griess法 ,观察GLPP对LPS诱导小鼠腹腔巨噬细胞一氧化氮(NO)产生的影响 ;以免疫组化法检测诱导型一氧化氮合成酶 (iNOS)的表达 ,观察GLPP对iNOS的影响。结果　GLPP(2 5～ 2 0 0mg·kg-1)灌胃给药 5d或体外给药 (3 12 5～ 2 0 0mg·L-1)均可促进巨噬细胞NO释放 ,但对LPS刺激NO的释放影响不大 ;GLPP(10 0mg·kg-1)灌胃给药 5d或体外给药 (10mg·L-1)均可使巨噬细胞iNOS含量增加。结论　GLPP可增加小鼠腹腔巨噬细胞NO产生 ,其机制可能与其促进巨噬细胞iNOS合成有关。     

Modulation of rat macrophage function by the Mangifera indica L. extracts Vimang and mangiferin

Vimang is an aqueous extract of Mangiferia indica L., traditionally used in Cuba as an anti-inflammatory, analgesic and antioxidant. In the present study, we investigated the effects of Vimang and of mangiferin (a C-glucosylxanthone present in the extract) on rat macrophage functions including phagocytic activity and the respiratory burst. Both Vimang and mangiferin showed inhibitory effects on macrophage activity: (a) intraperitoneal doses of only 50-250 mg/kg markedly reduced the number of macrophages in peritoneal exudate following intraperitoneal injection of thioglycollate 5 days previously (though there was no significant effect on the proportion of macrophages in the peritoneal-exudate cell population); (b) in vitro concentrations of 0.1-100 microg/ml reduced the phagocytosis of yeasts cells by resident peritoneal and thioglycollate-elicited macrophages; (c) in vitro concentrations of 1-50 microg/ml reduced nitric oxide (NO) production by thioglycollate-elicited macrophages stimulated in vitro with lipopolysaccharide (LPS) and IFNgamma; and (d) in vitro concentrations of 1-50 microg/ml reduced the extracellular production of reactive oxygen species (ROS) by resident and thioglycollate-elicited macrophages stimulated in vitro with phorbol myristate acetate (PMA). These results suggest that components of Vimang, including the polyphenol mangiferin, have depressor effects on the phagocytic and ROS production activities of rat macrophages and, thus, that they may be of value in the treatment of diseases of immunopathological origin characterized by the hyperactivation of phagocytic cells such as certain autoimmune disorders.     

Multiplexed cytokine detection in microliter microdialysis samples obtained from activated cultured macrophages

Microdialysis sampling probes were used to collect cytokine samples from lipopolysaccharide (LPS)-stimulated macrophages. The probes were immersed into cell culture wells containing either RAW 264.7 or isolated peritoneal macrophages. Dialysates (15 microL) from these wells were subjected to a multiplexed cytokine sandwich immunoassay platform analyzed by flow cytometry that measures up to six separate cytokines, interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-12p70 (IL-12p70), interferon-gamma (IFN-gamma), macrophage chemoattractant protein-1 (MCP-1), and tumor necrosis factor-alpha (TNF-alpha) in a single 15-muL sample. In vitro microdialysis sampling relative recovery experiments showed that only IFN-gamma, IL-6, MCP-1, and TNF-alpha could be recovered across a commercially-available 100-kDa MWCO microdialysis membrane. Eleven hours after LPS addition (1 microg/mL), RAW 264.7 macrophages secreted greater than 8000 pg/mL of TNF-alpha and greater than 1000 pg/mL MCP-1. With the peritoneal macrophages, greater than 6000 pg/mL of IL-6, MCP-1, and TNF-alpha were obtained. The maximum dialysate concentrations obtained from the RAW macrophages were 1300 pg/mL for TNF-alpha and 55 pg/mL for MCP-1. Maximum cytokine concentrations from peritoneal macrophage dialysates reached approximately 2000 pg/mL, 1100 pg/mL and 500 pg/mL for TNF-alpha, MCP-1 and IL-6, respectively. Microdialysis sampling allowed for 20-min samples to be collected during the cytokine release from the activated macrophages. These results demonstrate that microdialysis sampling can be used for collection of selected cytokines with improved temporal resolution.     

Augmentation of macrophage phagocytosis by modified arabinoxylan rice bran (MGN-3/biobran)

MGN-3/Biobran, modified arabinoxylan rice bran, has been shown to be a potent biological response modifier (BRM) as manifested by stimulation of different arms of the immune system such as NK, T and B cells; however, its effect on macrophages has not yet been studied. The effects of MGN-3 on macrophage function was examined in vitro using 3 models: human macrophage cell line U937, murine macrophage cell line RAW264.7, and murine peritoneal macrophages (P-M phi). Treatment with MGN-3 resulted in an increase in the percentages of attachment and phagocytosis of yeast by macrophages. The effect depends on the type of macrophage and the dose of MGN-3 applied. Macrophages also demonstrated enhancement in their spreading ability, post treatment with MGN-3. Results also showed that MGN-3, in a dose dependent manner (1, 10,100 microg/ml), significantly induced high levels of production of cytokines: TNF-alpha; and IL-6. In addition, MGN-3 significantly increased nitric oxide (NO) production. This data demonstrates that MGN-3 is a potent inducer of phagocytic function by macrophage, and suggests that MGN-3 is a useful agent for fighting microbial infection.     

Role of inducible nitric oxide synthase-derived nitric oxide in lipopolysaccharide plus interferon-gamma-induced pulmonary inflammation

Exposure of mice to lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma) increases nitric oxide (NO) production, which is proposed to play a role in the resulting pulmonary damage and inflammation. To determine the role of inducible nitric oxide synthase (iNOS)-induced NO in this lung reaction, the responses of inducible nitric oxide synthase knockout (iNOS KO) versus C57BL/6J wild-type (WT) mice to aspirated LPS + IFN-gamma were compared. Male mice (8-10 weeks) were exposed to LPS (1.2 mg/kg) + IFN-gamma (5000 U/mouse) or saline. At 24 or 72 h postexposure, lungs were lavaged with saline and the acellular fluid from the first bronchoalveolar lavage (BAL) was analyzed for total antioxidant capacity (TAC), lactate dehydrogenase (LDH) activity, albumin, tumor necrosis factor-alpha (TNF-alpha), and macrophage inflammatory protein-2 (MIP-2). The cellular fraction of the total BAL was used to determine alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) counts, and AM zymosan-stimulated chemiluminescence (AM-CL). Pulmonary responses 24 h postexposure to LPS + IFN-gamma were characterized by significantly decreased TAC, increased BAL AMs and PMNs, LDH, albumin, TNF-alpha, and MIP-2, and enhanced AM-CL to the same extent in both WT and iNOS KO mice. Responses 72 h postexposure were similar; however, significant differences were found between WT and iNOS KO mice. iNOS KO mice demonstrated a greater decline in total antioxidant capacity, greater BAL PMNs, LDH, albumin, TNF-alpha, and MIP-2, and an enhanced AM-CL compared to the WT. These data suggest that the role of iNOS-derived NO in the pulmonary response to LPS + IFN-gamma is anti-inflammatory, and this becomes evident over time.     

In vitro investigation on the effect of a plant preparation with antiviral activity on the functions of mice phagocyte cells

A polyphenol extract from the aerial roots of the medicinal plant Geranium sanguineum L. (PC) inhibited the reproduction of influenza viruses type A and B in vitro and in ovo and protected mice from mortality in the experimental influenza infection. The in vivo protective effect was connected with multiple biological activities of the preparation. The present paper focuses on the in vitro effects of the polyphenol extract on the functions of peritoneal and alveolar macrophages and blood polymorphonuclear leucocytes (PMNs), isolated from healthy ICR mice. It was found that PC in doses of 12.5 and 25 microg ml(-1) stimulated the phagocytic activity of peritoneal macrophages and blood PMNs. PC in the same doses did not significantly affect the phagocytic activity of alveolar macrophages, the migration of alveolar and peritoneal macrophages or the adherent activity of PMNs. Used in concentrations of 3.1-25.0 microg ml(-1), PC suppressed spontaneous NO production from peritoneal macrophages, while inducible NO production, provoked by LPS-, Ifn-gamma and LPS + Ifn-gamma inductions was not affected. The cell-toxic concentration of 100 microg ml(-1) increased spontaneous and LPS-inducible NO production. The experimental results demonstrated a stimulating effect of PC on the phagocytic activity of murine PMNs and peritoneal macrophages as well as a beneficial effect of the preparation on spontaneous NO production.     

Immunomodulatory activity of betulinic acid by producing pro-inflammatory cytokines and activation of macrophages

Betulinic acid (BA), a pentacyclic triterpene isolated from Lycopus lucidus, has been reported to be a selective inducer of apoptosis in various human cancer and shown anti-inflammatory and immunomodulatory properties. We postulated that BA modulates the immunomodulatory properties at least two groups of protein mediators of inflammation, interleukin-1beta (IL-1beta) and the tumor necrosis factor-alpha (TNF-alpha) on the basis of the critical role of the monocytes and tissue macrophages in inflammatory and immune responses. TNF-alpha and IL-1beta were produced by BA in a dose dependent manner at concentration of 0.625 and 10 microg/mL. The production of NO associated with iNOS was inhibited when treated with LPS at the concentration of 2.5 to 20 microg/mL of BA whereas COX-2 expression was decreased at 2.5 to 20 microg/mL. These modulations of inflammatory mediators were examined in LPS-stimulated RAW 264.7 cells and peritoneal macrophages. The morphology of macrophage was also examined and enhanced surface CD 40 molecule was expressed when treated BA at 0.625 to approximately 5 microg/mL with or without LPS. Furthermore, BA (20 microg/mL) enhanced apoptosis by producing DNA ladder in the RAW 264.7 cells. Our results indicated that BA induced activation of macrophage and pro-inflammatory cytokines. This may provide a molecular basis for the ability of BA to mediate macrophage, suppress inflammation, and modulate the immune response.     

Extract of the seed coat of Tamarindus indica inhibits nitric oxide production by murine macrophages in vitro and in vivo.

The seed coat extract of Tamarindus indica, a polyphenolic flavonoid, has been shown to have antioxidant properties. The present studies investigated the inhibitory effect of the seed coat extract of T. indica on nitric oxide production in vitro using a murine macrophage-like cell line, RAW 264.7, and in vitro and in vivo using freshly isolated B6C3F1 mouse peritoneal macrophages. In vitro exposure of RAW 264.7 cells or peritoneal macrophages to 0.2-200 microg/mL of T. indica extract significantly attenuated (as much as 68%) nitric oxide production induced by lipopolysaccharide (LPS) and interferon gamma (IFN-gamma) in a concentration-dependent manner. In vivo administration of T. indica extract (100-500 mg/kg) to B6C3F1 mice dose-dependently suppressed TPA, LPS and/or IFN-gamma induced production of nitric oxide in isolated mouse peritoneal macrophages in the absence of any effect on body weight. Exposure to T. indica extract had no effect on cell viability as assessed by the MTT assay. In B6C3F1 mice, preliminary safety studies demonstrated a decrease in body weight at only the highest dose tested (1000 mg/kg) without alterations in hematology, serum chemistry or selected organ weights or effects on NK cell activity. A significant decrease in body weight was observed in BALB/c mice exposed to concentrations of extract of 250 mg/kg or higher. Oral exposure of BALB/c mice to T. indica extract did not modulate the development of T cell-mediated sensitization to DNFB or HCA as measured by the local lymph node assay, or dermal irritation to nonanoic acid or DNFB. These studies suggest that in mice, T. indica extract at concentrations up to 500 mg/kg may modulate nitric oxide production in the absence of overt acute toxicity.     

Cloricromene, a coumarine derivative, protects against lethal endotoxin shock in rats.

Endotoxin shock was induced in male rats by an intravenous (i.v.) injection of Salmonella enteriditis lipopolysaccharide (LPS; 20 mg/kg i.v.). Survival rate, macrophage and serum tumor necrosis factor (TNF-alpha), mean arterial blood pressure (MAP) and white blood cell count were then evaluated. Furthermore the in vitro effect of cloricromene on peritoneal macrophage phagocytosis and TNF-alpha release by primed peritoneal macrophages was investigated. LPS administration caused animal death (0% survival 24 h after endotoxin challenge), hypotension, marked leukopenia and increased the levels of TNF-alpha in both serum and macrophage supernatants. Cloricromene administration (0.5, 1 and 2 mg/kg i.v. 15 min after endotoxin) protected against LPS-induced lethality (100% survival rate 24 h after endotoxin challenge), reverted LPS-induced hypotension and leukopenia, and decreased TNF-alpha in both serum and macrophage supernatants. Finally, cloricromene, added in vitro to peritoneal macrophages collected from endotoxin-treated rats increased macrophage phagocytosis and reduced TNF-alpha formation by activated mononuclear phagocytes. Our data suggest that cloricromene increases survival rate in endotoxin shock through an inhibition of TNF-alpha production.     

Smokeless tobacco extract decreases IL-12 production from LPS-stimulated but increases IL-12 from IFN-gamma-stimulated macrophages.

Modulation of IFN-gamma production from T cells by smokeless tobacco extract (STE) could be a factor in periodontal disease. The major inducer of IFN-gamma from T cells is bioactive IL-12 (p70), a heterodimeric protein composed of p35 and p40 subunits, while homodimeric IL-12 p40 antagonizes bioactive IL-12. Both p70 and p40 are produced by macrophages in response to lipopolysaccharide (LPS), IFN-gamma and/or CD40 ligation. To determine the impact of STE on IL-12 p40, p70 and IFN-gamma, splenic T cells were stimulated with anti-CD3 while splenic macrophages were stimulated with LPS in the presence or absence of STE. Production of IL-12 p40 and p70 from LPS-stimulated splenic macrophages and IL-12 p40, p70 and IFN-gamma from LPS/anti-CD3-stimulated T cells and macrophages was decreased by STE. To determine the impact of STE on macrophage IL-12 production alone, splenic or peritoneal macrophages were enriched and then stimulated. STE significantly diminished production of IL-12 p40 and p70 from LPS-stimulated peritoneal macrophages, LPS/IFN-gamma-stimulated peritoneal and splenic macrophages, but increased production of IL-12 p40 and p70 from IFN-gamma/CD40-stimulated splenic macrophages or IFN-gamma-stimulated peritoneal macrophages. None of the effects of STE on IL-12 was due to nicotine, rutin or chlorogenic acid. In contrast to STE, nicotine at 100 microg/ml significantly elevated production of IL-12 p40 and p70 from splenic macrophages stimulate by IFN-gamma/LPS. The results indicate that STE has a significant overall effect upon IL-12 production. It suppresses p40 and p70 production during responses to LPS or LPS/IFN-gamma but augments p40 and p70 production during responses to IFN-gamma without LPS. This affect could have a major impact on diseases associated with excessive production of IL-12.     

Activation of murine macrophage cell line RAW 264.7 by Korean propolis

Monocytes and macrophages play a major role in defense mechanism of the host response to tumor, in part through the secretion of several potent products and macrophage cytokines. Monocytes and tissue macrophages produce at least two groups of protein mediators of inflammation, interleukin 1 (IL-1) and tumor necrosis factor (TNF). Recent studies emphasizes that TNF and IL-1 modulate the inflammatory function of endothelial cells, leukocytes, and fibroblasts. In this study, our work is directed toward studying the in vitro effects of Korean propolis on the ability to induce cellular and secretory responses in murine macrophage cell line, RAW 264.7. It was found that Water Extract of Korean Propolis (WEP) could activate macrophages by producing cytokines. The production of the macrophage cytokines, IL-1 and TNF-alpha, by RAW 264.7 treated with WEP was examined from 2.5 microg/ml up to 25 microg/ml with dose dependent manner. Nitric oxide (NO) production was also increased when cells were exposed to combination of LPS and WEP from 2.5 microg/ml up to 25 microg/ml. At high dose of WEP (50 to 100 microg/ml) used to prescribe for anti-inflammatory and analgesic medicine showed inhibition of NO production in LPS-stimulated macrophage. Besides cytokine production, NO release, surface molecule expression and cell morphologic antigen expression were increased in response to the stimulation by WEP. These results suggested WEP may function through macrophage activation.     

Downregulation of peritoneal macrophage activity in mice exposed to bisphenol a during pregnancy and lactation

Bisphenol A (BPA) is an environmental endocrine disrupter that is known to be transferred to the fetus via the placenta and to the neonate via milk. In this study, we investigated BPA-induced alterations of the activities of murine peritoneal macrophages in dams and 7 week old offspring of dams exposed to BPA from gestational day 7 until lactation on day 21 after delivery, i.e. 34-36 days. BPA was administered in drinking water at three doses, 15, 75, and 300 mg/L. Dams were sacrificed 21 days after delivery and offspring at the age of 7 weeks. Peritoneal macrophages were cultured in the presence of LPS or LPS plus IFN-gamma for 2 or 4 days. We found that nitric oxide (NO) production by maternal macrophages was significantly decreased in a BPA-dose dependent manner. However, while a significant reduction of NO production by macrophages in the offspring was observed at BPA concentrations of 75 mg/L and 300 mg/L in drinking water, this effect was not seen at the lowest concentration of 15 mg/L. Similar inhibition of tumor necrosis factor-alpha (TNF-alpha) production was observed with macrophages from both BPA-exposed dams and offspring. Thus, our results suggest that exposure to BPA during gestation and lactation induces downregulation of the activities of macrophages in both dams and offspring.     

Comparison of effects of CH50 on macrophage activation and its anti-tumor activity with those of lipopolysaccharides

AIM: To investigate the characterization of pharmacological action & of CH50, a recombinant polypeptide of human fibronectin, by comparing the effects of CH50 on macrophage activation and its anti-tumor activity with those of lipopolysaccharides (LPS). METHODS: The production of nitric oxide (NO) as an index macrophage activation was determined by colorimetric assay. The interferon-gamma (IFN-gamma) transfection was performed with coprecipitation of calcium phosphate and DNA. The melanoma B16 cells were inoculated into abdominal cavity of mice and the number of tumor nodes was recorded. RESULTS: At lower concentrations or when given alone in vitro, CH50 produced ten times less NO than LPS (P < 0.01). But at concentrations higher than 1 mg.L-1, CH50 activated the IFN-gamma-primed macrophages to produce NO to the same extent as LPS (P > 0.05). There was no synergism between CH50 and LPS. Both CH50 and LPS alone could reduce the number of tumor nodes in abdominal cavity of mice but CH50 had a stronger inhibitory effect on the growth of tumor in vivo as compared to LPS (P < 0.01). CH50/IFN-gamma had also a better inhibitory effect on tumor growth in vivo than LPS/IFN-gamma did. CONCLUSION: In the presence of IFN-gamma, the ability of CH50 to activate macrophages is the same as that of LPS. But CH50 has better antitumorogenic effects in vivo against mouse melanoma as compared to LPS.