Immunomodulatory activity of methanolic extract of Amorphophallus commutatus var. wayanadensis under normal and cyclophosphamide induced immunosuppressive conditions in mice models

The present study investigates the immunomodulatory activity of methanolic extract of Amorphophallus commutatus var. wayanadensis (MEAC) under normal and cyclophosphamide induced immunosuppressive conditions in Swiss albino mice models. The splenocyte proliferation assay was performed to study in-vitro immunomodulatory activity of MEAC, where sheep RBC (SRBC) was used to induce immune responses in the experimental animals. The in-vivo immunomodulatory activity was evaluated by humoral antibody titer, quantification of plaque forming cells, qualitative hemolysis, delayed type hypersensitivity assay, phagocytic index and neutrophil adhesion assays. The chemoprotective effect of MEAC was determined against cyclophosphamide induced immunosuppression in mice models. MEAC exhibited significant mitogenic and co-mitogenic activity on Con-A, PHA and LPS stimulated splenocytes isolated from mouse spleen in a dose dependent manner. Furthermore, MEAC also elicited significant immunomodulatory activity with enhanced activation of humoral immune response along with a suppressive effect on cell mediated immune response. Hematological and histopathological analysis revealed the protective effect of MEAC against CP induced immunosuppression. The significant immunomodulatory activity of MEAC observed in the current study could be due to the fatty acids and phytosterols present in the extract.     

Ⅱ型超敏反应家兔模型的建立

目的建立Ⅱ型超敏反应家兔模型,为免疫毒理学或药效学研究提供新方法。方法家兔耳缘静脉注射绵羊红细胞(SRBC)5×108kg-1,每天1次,每周连续6d,停药1d,连续6周,诱导Ⅱ型超敏反应。每周观察呼吸和喷嚏等症状,并监测体温,检测血清游离血红蛋白和游离胆红素及尿隐血,计数外周血网织红细胞、中性粒细胞、淋巴细胞和血小板,测定血清谷丙转氨酶(GPT)和谷草转氨酶(GOT)活性及尿素氮和肌酐浓度,用Coombs实验法检测血清抗SRBC抗体水平。6周后处死家兔,测定肝、肾、脾和胸腺指数,并观察组织病理变化。结果与对照组相比,注射SRBC后1～6周,家兔呼吸和喷嚏等症状及体温未见明显变化,外周血网织红细胞数目和血清游离胆红素浓度未见明显变化。但从第1周开始出现尿隐血,第5周时血清游离血红蛋白显著增加,提示出现血管内溶血。外周血淋巴细胞从第1周开始显著增加,第4周时中性粒细胞明显减少,血小板数目未见明显变化,提示粒细胞受损伤。第1和第2周时血清GPT活性增加,第6周时GOT活性增加,尿素氮和肌酐水平未见明显变化。第3周时血清中出现抗SRBC抗体,第6周时脾脏和胸腺显著肿大,提示免疫系统参与此过程。第6周时肾脏、脾脏和胸腺组织未见明显变化,肝脏组织出现肝小叶排列紊乱、炎症细胞浸润和大量空泡等现象,提示肝脏有变性性损伤。结论家兔耳缘静脉注射SRBC6周可导致Ⅱ型超敏反应。     

Mechanism of enhanced humoral response in rodents by a synthetic polymer

We previously reported that administration of a low molecular weight (MW=800) synthetic polymer, NED 137, significantly increases humoral and cellular immune responses in the rat. The effect of NED 137 on the murine humoral response to T-dependent (TD) and T-independent (TI) antigens was studied in C57 BL/6, CBA/J and Balb/c mice. The TD antigens (SRBC, DNP-DA with adjuvant) or TI antigen (DNP-Ficoll) were administered simultaneously with NED 137. The polymer significantly increased the direct PFC response to all antigens tested in normal mice. However, it could not restore the PFC response to SRBC in athymic (nu/nu) mice. The effect of NED 137 on accessory cells was studied by the assessment of the in vitro response to SRBC in normal and macrophage-depleted rat spleen cultures. The polymer stimulated both, the primary and secondary IgM response and its immunopotentiating activity was the greatest in macrophage-depleted spleen cell preparations. The lack of effect of NED 137 in systems devoid of functional T cells, dependency on and specificity for a sensitizing antigen and its ability to stimulate a secondary response suggest that this polymer does not act as a "conventional" B-cell polyclonal activator.     

The effects of plantago-mucilage A from the seeds ofPlantago asiatica on the immune responses in ICR mice

Effects of plantago-mucilage A (P-MA) on the immune responses were studied in ICR mice. Mice were divided into 4 groups (10 mice/group), and P-MA at doses of 7, 21 and 63 mg/kg were orally administered to mice once a day for 21 consecutive days. Mice were immunized and challenged with sheep red blood cells (SRBC). P-MA at 63 mg/kg/day significantly increased the body weight gain and the relative weights of spleen and thymus, as compared with those in controls. However, there were no significant effects on liver weight due to P-MA treatment. Plaque forming cells (PFC) and hemagglutination (HA) titers to SRBC were significantly enhanced in mice dosed at 21 and 63 mg/kg/day P-MA, as compared with those in controls. Delayed-type hypersensitivity (DTH) reaction to SRBC, phagocyte activity and circulating leukocyte were also significantly increased in mice dosed at 63 mg/kg/day P-MA. These results demonstrate that P-MA markedly enhances both humoral immune and allergic reaction to SRBC at concentrations which don’t act on the relative weight of liver.     

Effects of single exposure to cadmium on the primary humoral antibody response

Effects of a single intraperitoneal (i.p.) injection of cadmium (Cd) on the primary humoral antibody responses against sheep red blood cells (SRBC) in mice were studied by assaying splenic plaque forming cells (PFC). PFC responses in mice were suppressed when exposed to Cd 2 days after immunization, and inconsistently stimulated when exposed before immunization. Dose-response relationships were observed in the suppressive effect of Cd exposure 2 days after immunization, but not consistently in the stimulative effect of Cd exposure before immunization. Thymus weights and cell numbers decreased markedly 4 days after Cd exposure with or without the antigenic stimulus. Splenic weights increased 2 days after Cd exposure, while the number of spleen cells was dramatically decreased 1 days after Cd exposure and still remained below normal 2 days after exposure.     

Compensation of cyclophosphamide immunosuppression by a bacterial immunostimulant (Broncho-Vaxom) in mice

The compensatory effect of a bacterial lysate, Broncho-Vaxom (BV) on the immunosuppressive action of cyclophosphamide (CY) was investigated. In CY immunosuppressed mice, BV treated animals recovered to normal levels of IgM and IgG in serum as well of IgA and IgG in gut secretions significantly earlier than controls. Furthermore, normal cell proliferation in thymus, as estimated by measuring the relative size of this organ was achieved earlier in BV treated mice than in control mice. Oral treatment with BV restores the number of IgM anti SRBC producing cells in spleen, in CY immunosuppressed mice. Since immunosuppression induced by CY increases the susceptibility to various infections, we tested in immunosuppressed animals the protective effect of BV towards IP challenge infections with Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae var ozaenae, Pseudomonas aeruginosa and Candida albicans. BV led to an enhanced resistance towards both pneumococci and staphylococci challenge infections but not to the other challenge microorganisms.     

Effect of traxanox on antibody formation in C57BL/6 mice

C57BL/6 mice, lower responders to sheep red blood cells (SRBC), were intraperitoneally immunized with 5 X 10(8) SRBC on day 0. Traxanox (10 and 30 mg/kg) administered orally on days 0 and 1 potentiated the production of spleen- and thymus-rosette forming cells (RFC) assessed on day 7. The production of hemolytic plaque forming cells (HPFC) to SRBC in the spleen of the syngeneic recipient mice assessed on day 4 was inhibited by the transfer of spleen-RFC obtained from the vehicle-treated donor mice, but not by that obtained from the traxanox (30 mg/kg)-treated donor mice. The same results were obtained in the thymectomized-recipient mice. The activity of the spleen-RFC obtained from the vehicle-treated donor mice was abolished by treatment with anti-Thy 1.2 or anti-Lyt 2.2 antibody and complement. On the other hand, the activity of the spleen-RFC obtained from the traxanox-treated donor mice was abolished by treatment with anti-Lyt 1.2 antiserum and complement. Traxanox (3 and 30 mg/kg) also caused the induction of the Thy 1.2-positive RFC in the spleen of the thymectomized mice. These results suggest that traxanox has a capacity to potentiate the immune responses to SRBC in C57BL/6 mice by the induction of Lyt 1.2-positive cells (helper T cells).     

Immune alterations in rats following subacute exposure to tributyltin oxide

Adult male Fischer 344 rats were dosed by oral gavage with bis(tri-n-butyltin)oxide (TBTO) in peanut oil for 10 consecutive days, at dosages ranging from 1.25 to 15 mg/kg/day. Other groups of rats were dosed daily for 10 days by oral gavage with cyclophosphamide (CY) at dosages ranging from 0.75 to 6 mg/kg/day. These rats served as positive controls for the immune assays employed. The immune function parameters examined included the following: delayed-type hypersensitivity (DTH) and antibody responses to bovine serum albumin (BSA), primary antibody responses to sheep red blood cells (SRBC) and trinitrophenyl lipopolysaccharide (TNP-LPS) and enumeration of splenic lymphocyte populations. The DTH and antibody responses to BSA were not affected by TBTO exposure; however these responses were suppressed in rats dosed with CY at 6 mg/kg/day. The plaque forming cell (PFC) response to the T cell-dependent antigen SRBC was enhanced in rats dosed with TBTO at from 5 to 15 mg/kg/day. On the other hand, the PFC response to the T cell-independent antigen TNP-LPS was unaffected by TBTO exposure. Rats dosed with CY had suppressed PFC responses to SRBC and TNP-LPS at dosages of 3 and 6 mg/kg/day, respectively. Enumeration of splenic lymphocyte populations from TBTO-exposed rats revealed a reduction in OX8- but not W3/25- or IgG-positive cells. These results, as well as results from an earlier study from this lab, suggest that T lymphocytes are a primary target for TBTO-induced immune alterations and that the enhancement of the PFC response to SRBC in TBTO-exposed rats may be mediated by alterations in the suppressor (OX8-positive) T lymphocyte population.     

国产环孢素A对小鼠免疫功能的抑制作用

当剂量为25～100mg/kg·d~(-1),ig×4d时,国产环孢素A(CsA)显著抑制小鼠脾脏空斑形成细胞数和溶血素生成,并呈剂量依赖方式。该剂量给药10d,可显著抑制2,4—二硝基氯苯所致小鼠迟发型皮肤超敏反应。CsA(50 mg/kg·d~(-1),ig×14d)能明显延长小鼠移植心脏的存活时间。CsA(50,100mg/kg·d~(-1),ig×4d)对小鼠iv碳粒廓清速率和骨髓细胞数均无明显影响。国产CsA和进口CsA对小鼠脾脏空斑形成细胞反应的抑制作用无显著差异。     

Effects of Tremella polysaccharides on immune function in mice

It was found in vitro that Tremella polysaccharides (TP) (50, 100, 150 and 200 micrograms/ml) augmented lymphocyte proliferation induced by Con A and did not antagonize the suppressive effect of hydrocortisone on lymphocyte proliferation. In vivo TP promoted the plaque-forming cell (PFC) response to SRBC in mice. TP 50 and 100 mg/kg ip for 5 d produced 77.6% and 81.8% increases in PFC response respectively. At the doses of 150 and 200 micrograms/ml, TP decreased the interleukin 2 (IL-2) activities in the supernatant of culture media of mouse spleen cells. TP (50 micrograms/ml) enhanced the lymphocyte proliferation induced by Con A and increased the PFC response to SRBC by 47.1% in 14-month-old mice.     

Immunosuppressive activities of deoxyspergualin. II. The effect on the antibody responses

We examined the suppressive effect of a newly developed antitumor agent, 15-deoxyspergualin (DSP), on the plaque-forming cell responses to various antigens. The intraperitoneal injections of DSP at a dose of 5.0 mg/kg body weight suppressed drastically the development of plaque-forming cells in the spleen of C57BL/6 mice immunized with sheep red blood cells (0.2 ml of a 5% suspension), trinitrophenyl-lipopolysaccharide (1 microgram/mice) and trinitrophenyl-Ficoll (100 micrograms/mice). These suppressive effects were observed when the administration of DSP was started after the injection of antigens. The responsiveness of spleen cells from DSP-treated mice was also checked in in vitro culture. Responsiveness to lipopolysaccharide in vitro was not reduced. Furthermore DSP did not significantly suppress the responsiveness of spleen cells to succinylated concanavalin A or production of interleukin-1 or -2. The results are discussed with regards to the mode of action of DSP on immune responsiveness.     

Effect of chloroquine and some other antimalarials on the immune mechanism in experimental animals

The effects of chloroquine and some other antimalarials on the immune responses in experimental animals have been examined. Chloroquine and quinine caused significant decrease of serum anti−SRBC haemagglutination titre. Chloroquine lowered the serum IgM level and also reduced plaque−forming cells in the spleen of mice. The delayed−type hypersensitivity responses to SRBC and the passive cutaneous anaphylaxis were also diminished in rats treated with chloroquine. Thus, the immunosuppressant activity of chloroquine may explain its efficacy in various types of immune disorders.     

SA3443, a novel cyclic disulfide compound, depresses anti-SRBC antibody-forming cell responses in the mouse through inhibition of antigen-presenting cell activities.

(4R)-Hexahydro-7,7-dimethyl-6-oxo-1,2,5-dithiazocine-4-carboxylic acid (SA3443) is a newly synthesized cyclic disulfide compound which has potential hepatoprotective properties. The effect of SA3443 on the induction of anti-sheep red blood cell (SRBC) plaque (antibody) forming cell (PFC) responses was investigated in vivo and in vitro. SA3443 (approximately 3 mg/kg/day) remarkably decreased the number of anti-SRBC PFC in the spleens of mice immunized with a high dose of SRBC in vivo. The addition of SA3443 (approximately 1 x 10(-7) M) at the initiation of mouse spleen cell cultures in vitro also exerted a significant inhibitory effect on subsequent PFC response to SRBC, and removal of SA3443 after 24 h did not reverse its inhibitory effect. Pre-incubation of isolated adherent spleen cells with SRBC and SA3443 resulted in a similar inhibition of subsequent PFC response, but a pre-incubation of macrophage-depleted cells with SRBC and SA3443 or a pre-incubation of the unseparated spleen cells with SA3443 in the absence of SRBC had no effect. These findings have suggested that SA3443 may depress antibody response through inhibition of macrophage antigen-presenting cell activity.     

RM-11, an isoxazole derivative, accelerates restoration of the immune function in mice treated with cyclophosphamide

The aim of this study was to evaluate efficacy of an isoxazole derivative RM11 to accelerate reconstitution of selected immune activities in cyclophosphamide (CP)-immunocompromised mice. We demonstrated that administration of fifteen 10 mug intraperitoneal doses of RM11, following a sublethal (200 mug/kg) dose of CP, significantly stimulated the number of antibody-forming cells (AFC) to sheep erythrocytes (SRBC) as determined 35 days after the CP treatment. Similarly, treatment of the CP-injected mice with 7 doses of RM11 significantly enhanced generation of delayed type hypersensitivity (DTH) to ovalbumin (OVA). Moreover, in that model, the treatment of mice with RM11 accelerated the process of myelopoiesis. RM11 also counteracted the suppressive action of methotrexate (MTX) in the in vitro model of the humoral immune response to SRBC. The phenotypic studies with fluorocytometer revealed that intraperitoneal 10 mug dose of RM11 significantly elevated the percentage of mature (CD3(+), CD4(+) and CD8(+)) T cells in the spleen and down-regulated the content of CD19(+) cells. We conclude that RM11 may be of potential therapeutic value in restoration of the immune status in patients undergoing chemotherapy.     

Immunotoxicity of paraquat after subacute exposure to mice

The immunotoxic effect of paraquat (PQ), a herbicide that has been used widely in agriculture was investigated using Balb/c mice. Paraquat was administered at doses of 1, 0.1, and 0.01 mg/kg for 21 days. Body weight, organ weight, cellularity of spleen, delayed type of hypersensitivity (DTH) response, plaque-forming cell (PFC) assay, hemagglutination titer (HA), quantitative hemolysis of SRBC (QHS) assay, spleen cell subtypes, cytokine production and lymphocyte proliferation assay were studied in various groups of animals. Results showed that high dose of PQ (1 mg/kg) could suppress both cellular and humoral activity of the immune system. PQ at medium dose (0.1 mg/kg) did not show any changes in organ weight, body weight and spleen cellularity but significantly decreased the proliferation response to PHA and the production of IFNγ. PQ at low dose (0.01 mg/kg) did not produce any significant changes in humoral or cellular responses of the immune system. In conclusion, paraquat at high dose has an inhibitory effect on the cell-mediated and humoral immunity. It seems that PQ has no adverse effects on mice immune system at low doses of 0.01 mg/kg, which is two times the PQ allowed daily intake (ADI) limit.     

Effects of suplatast tosilate (IPD-1151T) on antibody formations in mice]

We examined the effects of suplatast tosilate (IPD-1151T) on antibody formation in mice, and the following results were obtained: 1) IPD-1151T clearly increased the productions of IgM and IgG-hemolytic plaque forming cells (PFC) in mice immunized with sheep red blood cells (SRBC) when the agent was given p.o. for 5 days from the day of immunization. 2) IgM and IgG-PFC productions in old mice, 60 weeks of age, were clearly lower than those in adult mice, 10 weeks of age; and an oral administration of IPD-1151T significantly recovered the decayed PFC-production in the old mice. 3) IPD-1151T clearly suppressed the production of anti-dinitrophenyl (DNP)-IgE antibody in mice when the agent was given p.o. for 5 days from the day of immunization, whereas the agent did not affect anti-DNP-IgM and IgG antibody productions. 4) IPD-1151T did not affect the induction phase of the cellular immune reaction of picryl chloride-induced contact dermatitis and the SRBC-induced footpad reaction. Our present results suggest that IPD-1151T has a class-specific suppressive effect on the production of IgE antibody, but does not suppress the other immune responses.     

Evaluation of immune function in mice exposed to Ordram

The potential effects that the thiocarbamate herbicide Ordram has on the immune system of mice was evaluated following 12 days of acute dosing by oral gavage. Dosages of Ordram ranging from 20 to 320 mg/kg/day had no consistent significant effects on a variety of immune parameters investigated. The immune parameters measured were the following: body and lymphoid organ weights; splenic natural killer (NK) cell activity; lymphoproliferative responses to B and T lymphocyte mitogens and allogeneic spleen cells in a one-way mixed lymphocyte reaction; and delayed-type hypersensitivity and antibody responses to sheep red blood cells (SRBC). The effects that the immunosuppressant cyclophosphamide has on these immune parameters was also examined. The results indicate that Ordram does not appear to affect key parameters of the immune system of mice under the conditions of exposure employed.     

Humoral and cell mediated immune response to cadmium in mice

The effect of 30, 100 and 300 ppm of cadmium chloride (CdCl2) exposure for 35 days on humoral and cell mediated immune response was examined in Swiss Albino mice. Body burden of cadmium in kidney, spleen and liver was determined and histopathology of these organs was also done. Cadmium chloride in doses of 100 and 300 ppm when fed in drinking water caused significant decrease in IgM and IgG titre against sheep red blood cells (SRBC) and a significant decrease in IgG titre against bovine serum albumin (BSA). The delayed type hypersensitivity response to SRBC and splenic T cell proliferation to BSA was also significantly decreased following 100 amd 300 ppm cadmium exposure. Cadmium accumulation in the spleen, liver and kidney was associated with degeneration and inflammatory changes. It is concluded that cadmium causes significant suppression of humoral and cell mediated immune response in mice which could be due to its cytotoxic action on liver, kidney and immune cells.     

Analysis of lead effects on in vivo antibody-mediated immunity in several mouse strains

The effect of administration of lead acetate (10 mM in the drinking water) for 8 weeks on the in vivo sheep red blood cell (SRBC) specific plaque-forming cell (PFC) responses of inbred A, BALB/c, C57Bl/6, DBA/1, SJL, and NZW/NZB F1 mice and outbred CFW mice was examined to determine if lead was immunomodulatory in a genetically related manner. Lead did not suppress the SRBC-specific PFC/10(6) splenocytes or PFC/spleen response in any mouse strain when compared to the responses of strain-matched control mice. In addition, 10 mM lead-treated BALB/c mice manifested augmented PFC/10(6) splenocytes (17%; p less than .05) but unchanged PFC/spleen responses. Correspondingly, serum concentrations of SRBC-specific antibody (measured by radioimmunoassay) and serum immunoglobulin G, M, or A isotypes were also unchanged by lead acetate treatment in all tested mouse strains. There were no observable lead-related histopathological changes or deposition of immune complexes or antibasement membrane antibody in the kidneys of treated mice. Further, splenocytes from lead-treated, SRBC-immunized mice cultured with T-independent antigens (TNP-LPS, TNP-Ficoll) or with a T-dependent antigen (SRBC) exhibited direct and indirect specific PFC responses that were unchanged from those of control mice. The H-2K/D haplotypes of the outbred CFW mice were determined by microcytotoxicity to include r, q, u, and s. These results suggest that lead acetate (10 mM) administered po for 8 weeks does not suppress the primary direct humoral immune response to SRBC in inbred and outbred mice of several H-2 haplotypes (k/d; d; b; q; d,z; s; r; and u).     

Modification of immune response by cinnarizine

Effects of cinnarizine on immune response in mice were investigated. Mice were orally administered with cinnarizine and were immunized with sheep red blood cells (SRBC) intravenously. Numbers of plaque forming cells (PFC) to SRBC in spleen of these mice were assayed and delayed-type hypersensitivity (DTH) response to SRBC was measured. 1) PFC response in immunization with 5 X 10(6) cells/mouse of SRBC was enhanced by administration of 25 mg/kg of cinnarizine, while the response in immunization with 5 X 10(8) cells/mouse was suppressed by 25 to 200 mg/kg of cinnarizine. 2) From study on timing of administration, suppression of PFC response by 6.25 to 200 mg/kg of cinnarizine was observed at 24 hr. after the immunization. 3) 12.5 to 200 mg/kg of cinnarizine suppressed polyclonal B cell activation induced by lipopolysaccharide (LPS). 4) Colchicine induced suppressor T cell inactivation was prevented by administration of 50 mg/kg of cinnarizine and it was suggested that cinnarizine may induce suppressor T cells from the study of adoptive cell transfer system. 5) 50 mg/kg of cinnarizine showed the suppression of DTH response in expression phase, but not in induction phase. It was concluded that immune responses in mice were modified by cinnarizine.