Water extract of Cayratia albifolia C.L.Li root relieves zymosan A-induced inflammation by restraining M1 macrophage polarization

BACKGROUND

Cayratia albifolia C.L.Li (CAC) is a traditional Chinese herbal medicine used to treat inflammatory diseases. Our laboratory has firstly reported that the water extract from CAC relieved lipopolysaccharide (LPS)-induced inflammation, however stronger evidence is still needed to prove its anti-inflammatory effects and the mechanisms involved are also ambiguous.

PURPOSE

This study sought to provide more evidence for the application of CAC in alleviating infectious inflammation and disclose novel pharmacological mechanisms.

METHODS

Mice were injected with zymA into their paws or peritoneal cavities, and then treated with CAC. ELISA, immunofluorescence and flow cytometry were performed to detect the cytokines (IL-1β, IL-6, TNF-α and IL-10) generation, the cell infiltration, and the CD86 or CD206 expression of macrophages. Then in vitro assays were performed on bone marrow-derived macrophages (BMDMs) and peritoneal macrophages (PMs) to detect their expression of iNOS, arg-1 and the cytokines above. On mechanisms, western blotting (WB), electrophoretic mobility shift assay (EMSA) and flow cytometry were carried out to measure NF-κB transcriptional activity, mitochondrial bioactivity and the mTORC1 activation when BMDMs were stimulated by zymA and treated with CAC. Finally, the chemical components consisted in the extract were analyzed by LC-MS.

RESULTS

200 mg/kg CAC clearly inhibited zymA induced mouse paw edema and reduced the contents of IL-1β, IL-6 and TNF-α rather than IL-10 in local tissues. CAC also reduced CD86 but not CD206 in macrophages in situ. Through in vitro experiments, it was discovered that CAC reduced the protein and mRNA levels of IL-1β, IL-6 and TNF-α, and also inhibited iNOS expression, but showed no influence on IL-10 and arg-1 in macrophages. We found CAC reduced NF-κB transcriptional activity, down-regulated mitochondrial membrane potential and ROS levels, and inhibited mTORC1 activity. Finally, we identified 15 major compounds in the extract, among which 4-guanidinobutyric acid and kynurenic acid were the most abundant.

CONCLUSION

This study provides further evidence that CAC significantly reduces zymA induced infectious inflammation. In addition, this novel data revealed that CAC restrained M1 rather than promoting M2 macrophages polarization via multi-target inhibitory effects, based on its potentially active components.

Preliminary study of the toxicity and radioprotective effects of zymosan in vitro and in vivo

BACKGROUND

This study aimed to confirm the cytotoxicity of zymosan in vitro and in vivo and determine the appropriate treatment time and the dose of zymosan.

METHODS

AHH-1 cells and HIECs were administered by 0, 20, 40, 80 or 160 μg/mL zymosan. The CCK-8 assay and flow cytometry were used to evaluate the cell viability and apoptosis 24 h, 48 h, and 72 h after administration. Furthermore, 12 h before irradiation, the cells were treated with 0, 5, 10, or 20 μg/mL zymosan and then irradiated with 4 Gy X-rays. Cell viability and apoptosis were measured by the CCK-8 assay and flow cytometry at 24 h. In addition, the protective effect of zymosan against radiation in vitro was compared to that of 20 μg/mL LPS. In vivo, weight, the spleen index, and the thymus index were measured to evaluate the toxicity of 0, 5, 10, 20, and 10 mg/kg zymosan. In addition, rats were treated with 0, 2, 4, 8, or 10 mg/kg zymosan and then irradiated with 7 Gy X-rays. The survival rate, organ index were evaluated. The protective effect of zymosan against radiation in vivo was compared to that of 10 mg/kg LPS a positive control.

RESULTS

The viability and apoptosis of cells treated with different doses and treatment times of zymosan were not different from those of control cells (p < 0.05). Furthermore, cell viability and apoptosis were clearly improved after zymosan preadministration (p < 0.05). The radioprotective effect of zymosan was dose-dependent. In addition, the viability of cells pretreated with zymosan was higher than that of cells pretreated with LPS, and the apoptosis rate of zymosan-treated cells was lower than that of cells pretreated with LPS (p < 0.05). In vivo, weight, the spleen index and the thymus index were significantly decreased by zymosan at a concentration of 20 mg/kg (p < 0.05). Further experiments showed that the concentration at which zymosan exerted radioprotective effects was 10 mg/kg. The survival curves in the irradiated rats were barely separated between the LPS treatment and zymosan treatment.

CONCLUSION

Zymosan administration before radiation exposure significantly increased cell viability and the survival rates of rats.

Controlling pathological pain by adenovirally driven spinal production of the anti-inflammatory cytokine, interleukin-10

Gene therapy for the control of pain has, to date, targeted neurons. However, recent evidence supports that spinal cord glia are critical to the creation and maintenance of pain facilitation through the release of proinflammatory cytokines. Because of the ability of interleukin-10 (IL-10) to suppress proinflammatory cytokines, we tested whether an adenoviral vector encoding human IL-10 (AD-h-IL10) would block and reverse pain facilitation. Three pain models were examined, all of which are mediated by spinal pro-inflammatory cytokines. Acute intrathecal administration of rat IL-10 protein itself briefly reversed chronic constriction injury-induced mechanical allodynia and thermal hyperalgesia. The transient reversal caused by IL-10 protein paralleled the half-life of human IL-10 protein in the intrathecal space (t(1/2) approximately 2 h). IL-10 gene therapy both prevented and reversed thermal hyperalgesia and mechanical allodynia, without affecting basal responses to thermal or mechanical stimuli. Extra-territorial, as well as territorial, pain changes were reversed by this treatment. Intrathecal AD-h-IL10 injected over lumbosacral spinal cord led to elevated lumbosacral cerebrospinal fluid (CSF) levels of human IL-10, with far less human IL-10 observed in cervical CSF. In keeping with IL-10's known anti-inflammatory actions, AD-h-IL10 lowered CSF levels of IL-1, relative to control AD. These studies support that this gene therapy approach provides an alternative to neuronally focused drug and gene therapies for clinical pain control.

Adjuvant treatment for complement activation increases the effectiveness of photodynamic therapy of solid tumors

Phototoxic lesions generated in tumor tissue by photodynamic therapy (PDT) are recognized by the host as a threat to the integrity and homeostasis at the affected site. Among the canonical pathways invoked by the host for dealing with this type of challenge is the activation of the complement system, integrating proteins that serve as molecular sensors of danger signals produced by PDT and those initiating signalling cascades coupled into the network of inflammatory and immune responses. Since the activated complement system is a salient participant of the antitumor response produced by PDT, it is worth exploring whether its manipulation can be exploited for the therapeutic benefit. Using mouse tumor models, the present study examined the potential of representative complement-activating agents to act as effective adjuvants to PDT. Tumor-localized treatment with zymosan, an alternative complement pathway activator, reduced the recurrence-rate of PDT-treated tumors, markedly increasing the percentage of permanent cures. In contrast, a similar treatment with heat aggregated gamma globulin (complement activator via the classical pathway) was of no significant benefit as a PDT adjuvant. Systemic complement activation with streptokinase treatment had no detectable effect on complement deposition at the tumor site without PDT, but it augmented the extent of complement activity in PDT-treated tumors. This finding based on immunohistochemistry analysis explains the results of tumor therapy experiments, which showed that systemic treatment with streptokinase or a similar agent, urokinase, enhances the PDT-mediated tumor response. Zymosan and streptokinase administrations produced no beneficial results with PDT of tumors growing in complement-deficient mice. This study, therefore, establishes the potential of complement-activating agents to serve as effective adjuvants to PDT for cancer treatment.

Continuous dialysis with bicarbonate/lactate-buffered peritoneal dialysis fluids results in a long-term improvement in ex vivo peritoneal macrophage function

To circumvent the potentially negative consequences of long-term exposure to unphysiologic acidic lactate-buffered peritoneal dialysis fluids (PDF), neutral pH solutions buffered with bicarbonate/lactate have recently been introduced in phase 2 and 3 clinical trials. This study examines the longitudinal changes in peritoneal macrophage (PMØ) function in patients dialyzed continuously with either lactate (LPD; 40 mM lactate, pH 5.2)-buffered or bicarbonate/lactate (TBL; 25 mM/15 mM bicarbonate/lactate, pH 7.3)-buffered PDF. Before the study, during the run in period of a phase 3 clinical trial, all patients had been taking LPD for at least the previous 18 wk. At the beginning of the study (day 0), both constitutive and serum-treated zymosan (STZ) stimulated tumor necrosis factor alpha (TNF-alpha) synthesis were assessed in PMØ isolated from 12-h dwell effluent (with 1.36% glucose) in all patients. The patients were subsequently randomized to either continuous TBL or LPD therapy and PMØ function was assessed after further 3- and 6-mo periods in all patients. At all time points measured STZ induced a dose-dependent increase in PMØ TNF-alpha secretion (P = 0.043 versus control for doses greater than 100 microg/ml). In patients continuously dialyzed with LPD, constitutive PMØ TNF-alpha synthesis levels (mean +/- SEM, pg/10(6) PMØ per18 h, n = 5 patients) were 154 +/- 65, 261 +/- 60, and 101 +/- 99 at 0, 3, and 6 mo, respectively. Stimulated STZ (1000 microg/ml) levels were 1340 +/- 519, 1046 +/- 586, and 758 +/- 250 at 0, 3, and 6 mo, respectively. In patients dialyzed with TBL, constitutive PMØ TNF-alpha synthesis levels (pg/10(6) PMØ per 18 h, n = 5 patients) were 300 +/- 136, 106 +/- 35, and 213 +/- 62 at 0, 3, and 6 mo, respectively. Stimulated STZ (1000 microg/ml) levels were 1969 +/- 751, 1541 +/- 330, and 2670 +/- 671 at 0, 3, and 6 mo, respectively. At 6 mo, STZ-stimulated PMØ TNF-alpha synthesis was significantly higher in patients treated with TBL compared with those treated with LPD (P = 0.0035). These data suggest that in patients continuously dialyzed with a neutral pH solution, there is a long-term improvement in PMØ function compared with patients on conventional therapy. Better PMØ function suggests improved host defense status and may affect the peritoneum's susceptibility to infection and potentially reduce the negative consequences of repeated intraperitoneal inflammation on long-term membrane function.

The mechanisms of serum-treated zymosan (STZ)-induced oxidative metabolism by human eosinophils and the effects of IL-5 priming

BACKGROUND

The aim of this work was to study the mechanisms of action of IL-5 on the subsequent stimulation of the oxidative metabolism of blood eosinophils by serum-treated zymosan (STZ), in terms of signal transduction characteristics, and by comparing the response of cells from healthy and allergic subjects during environmental exposure to birch pollen.

METHODS

Eosinophils from healthy controls and allergic patients were purified to over 95% by Percoll gradients and the MACS system. Oxidative metabolism was measured by a lucigenin-enhanced chemiluminescence (CL) assay. Eosinophils were primed with IL-5 and subsequently stimulated with STZ. The signal transduction mechanisms of IL-5 priming were studied with the MEK inhibitor PD 98059,the PkC inhibitors staurosporine and Ro 318220, and the PI3 kinase inhibitor wortmannin.

RESULTS

IL-5 increased the maximum radical production (P=0.0079) and reduced the t(1/2) rise (0.000018) of the CL reactions. The t(1/2) rise was PkC dependent and MEK independent, while the maximum radical production was PkC, MEK, and PI3 kinase dependent. During the pollen season, IL-5 reduced the total STZ-induced CL response in the patients' cells (P=0.016), but not in the control cells, whereas it primed the response to STZ of both cell populations in terms of the t(1/2) rise (P=0.012 and 0.00066, respectively).

CONCLUSION

STZ-induced oxidative metabolism consists of different stages. The initial stage (t(1/2) rises of the curves) is PkC dependent and MEK independent, while the end stage (maximum radical production) is PkC, MEK, and PI3 kinase dependent. IL-5 shortened the initial stage, and increased the end stage. During allergen exposure, however, the end stage was reduced by IL-5. This could be due to increased amounts of hypodense eosinophils and/or some abnormality in cell responses.

Critical role of Kupffer cell CR3 (CD11b/CD18) in the clearance of IgM-opsonized erythrocytes or soluble beta-glucan

Liver macrophages (Kupffer cells) play a major role in blood clearance of both C3-opsonized immune complexes and therapeutic beta-glucan polysaccharides. Human Kupffer cells express three types of C3-receptors: CR1 (C3b-receptor; CD35), CR3 (iC3b- and beta-glucan-receptor), and CR4 (iC3b-receptor; CD11c/CD18). Studies of isolated macrophages have suggested that CR3 is the major receptor mediating capture of either C3-opsonized erythrocytes (E) or beta-glucans. In this investigation, the organ distribution and function of CR3 in the clearance of IgM-opsonized E and soluble CR3-binding polysaccharides were explored in normal vs. CR3-knockout (CR3-KO) mice. Analysis of intravenously (i.v.) injected 125I-anti-CR3 showed that the major vascular reservoir of CR3 was the liver, followed by spleen and lungs. By contrast, clearance of 125I-anti-CR1 appeared to be mediated predominantly by splenic B lymphocytes, as only subsets of splenic macrophages or Kupffer cells were found to express CR1. Clearance of IgM-opsonized 51Cr-E occurred rapidly to the livers of normal mice but was nearly absent in CR3-KO mice. Soluble 125I-beta-glucan exhibited rapid clearance to the liver in normal mice, whereas clearance in CR3-KO mice was significantly reduced. In conclusion, Kupffer cell CR3 plays a crucial role in the clearance of both IgM-opsonized E and beta-glucans.

Beta-glucan, a "specific" biologic response modifier that uses antibodies to target tumors for cytotoxic recognition by leukocyte complement receptor type 3 (CD11b/CD18)

beta-Glucans were identified 36 years ago as a biologic response modifier that stimulated tumor rejection. In vitro studies have shown that beta-glucans bind to a lectin domain within complement receptor type 3 (CR3; known also as Mac-1, CD11b/CD18, or alphaMbeta2-integrin, that functions as an adhesion molecule and a receptor for factor I-cleaved C3b, i.e., iC3b) resulting in the priming of this iC3b receptor for cytotoxicity of iC3b-opsonized target cells. This investigation explored mechanisms of tumor therapy with soluble beta-glucan in mice. Normal mouse sera were shown to contain low levels of Abs reactive with syngeneic or allogeneic tumor lines that activated complement, depositing C3 onto tumors. Implanted tumors became coated with IgM, IgG, and C3, and the absent C3 deposition on tumors in SCID mice was reconstituted with IgM or IgG isolated from normal sera. Therapy of mice with glucan- or mannan-rich soluble polysaccharides exhibiting high affinity for CR3 caused a 57-90% reduction in tumor weight. In young mice with lower levels of tumor-reactive Abs, the effectiveness of beta-glucan was enhanced by administration of a tumor-specific mAb, and in SCID mice, an absent response to beta-glucan was reconstituted with normal IgM or IgG. The requirement for C3 on tumors and CR3 on leukocytes was highlighted by therapy failures in C3- or CR3-deficient mice. Thus, the tumoricidal function of CR3-binding polysaccharides such as beta-glucan in vivo is defined by natural and elicited Abs that direct iC3b deposition onto neoplastic cells, making them targets for circulating leukocytes bearing polysaccharide-primed CR3. Therapy fails when tumors lack iC3b, but can be restored by tumor-specific Abs that deposit iC3b onto the tumors.

Mouse paw oedema induced by Habu snake (Trimeresurus flavoviridis) venom: inhibition by morphine, naloxone and methylnaloxone alone or in combinations

The oedema produced in the mouse by intraplantar injection of the venom of Trimeresurus flavoviridis was inhibited by morphine (Mo) and by naloxone (Nx); the action of Mo increased with the dose, whereas that of Nx first progressed and thereafter regressed with the dose; very small doses of Nx antagonized Mo. Methylnaloxone (MeNx), a quaternary ammonium derivative of Nx was much less effective than Nx by the subcutaneous route but almost as effective by the intraplantar route. Peripheral opioidergic receptors are thus likely to be involved. Very high doses of Mo acted an synergistically with an optimal dose of EDTA or zymosan; complex interactions occurred between lower doses of Mo or Nx and EDTA or zymosan.

Effect of interferon-alpha (IFN alpha) on various human tumor xenografts

The growth of some human tumor xenografts (3 out of 8, melanoma, non-Hodgkin's lymphoma, squamous cell carcinoma) was successfully--but moderately and temporarily--inhibited, when interferon-alpha (EGIS, Hungary) was given for 10 days. The route of administration (intratumoral or intraperitoneal) was usually not a decisive factor. An attempt to potentiate IFNa action with Zymozan or Cyclophosphamide did not succeed.

Protection of mice against Babesia microti with cord factor, COAM, zymosan, glucan, Salmonella and Listeria

Cord factor (trehalose 6-6' dimycolate). COAM (chlorite-oxidized oxyamylose), zymosan, glucan, Salmonella enteritidis 11RX and Listeria monocytogenes were found to protect mice against subsequent infection with Babesia microti, an intra-erythrocytic protozoan parasite. This protection was not observed after injection of Staphylococcus epidermidis, a viridans group Streptococcus, thioglycollate, or colloidal carbon. All the agents which protect against B. microti have also been reported to induce non-specific protection against experimental tumours. The parasites appear to die inside circulating red cells. This implies that these can exert non-specific protection against this parasite through the mediation of a soluble factor.

Enhancement of local immune response in the treatment of experimental peritonitis

We conclude from these experiments that the host defense in peritoneal infections rests largely on the phagocytic cells attracted into the peritoneal cavity by the offending organism, and that an increase in the number of available phagocytes by pretreatment with chemotactic substances protects against lethal peritoneal infections. There seems to be a direct relationship between the number of available phagocytes in the peritoneal cavity at the time of inoculation and the reduction of mortality in experimental peritonitis (Fig. 1).

Defective neutrophil locomotion in human blastomycosis: evidence for a serum inhibitor

Unstimulated or stimulated locomotion, bactericidal, and metabolic activities of polymorphonuclear leukocytes (PMN) from 12 nonimmunosuppressed patients with invasive fungal infections proved by culture, were evaluated before and after treatment of the patients with antimicrobial drugs. The major observation was that PMN from patients with blastomycosis had a defect in stimulated locomotion. The specificity of the defect for blastomycosis was substantiated by the normal stimulated locomotion of PMN from uninfected control subjects or untreated patients with histoplasmosis, cryptococcosis, coccidioidomycosis, or sporotrichosis. The defect was due to a heat-stable, cell-directed, reversible serum inhibitor. In unheated or heated serum from untreated patients with blastomycosis, control PMN had decreased stimulated locomotion. Multiple washing followed by addition of control serum corrected locomotion of PMN from untreated patients with blastomycosis. The abnormality was not present in PMN from patients who had been treated with amphotericin B or had spontaneous resolution of their infections. Inhibition was not due to absence of chemoattractant activity because zymosan-activated patient serum or mixtures of patient and control serum stimulated PMN locomotion normally. The defect did not correlate with age, sex, neutrophil count, nitroblue tetrazolium reduction, serologic reactivity, or duration or severity of infection. No defect was found in bactericidal or metabolic activities of various combinations of PMN and serum from untreated or treated patients with blastomycosis or the 4 other fungal infections tested, indicating that the inhibitor was specific for stimulated locomotion.

Evaluation of the mechanism of zymosan-induced resistance to experimental peritonitis

Three injections of intraperiotoneal (IP) zymosan-induced profound resistance to E. coli peritonitis in Sprague-Dawley rats. IP zymosan had minimal effects on organ weights and systemic phagocytic clearance ability, suggesting that this mode of administration had few systemic reticuloendothelial system (RES) effects. Hemoglobin (a known inhibitor of local phagocytosis) reduced the protection induced by zymosan, giving further evidence that IP zymosan acts locally. IP zymosan stimulation results in an initial marked influx of polymorphonuclear cells followed by a greater percentage replacement of mononuclear cells by the third day. Examination of these cells via chemiluminescence studies demonstrated that the phagocytic capacity of zymosan-stimulated peritoneal cells was markedly greater than the control group on a cell-for-cell basis. IP zymosan also gave some protection against intravenous (IV) E. coli, but IV zymosan did not significanly protect against IP E. coli. Possible mechanisms of action are discussed. These findings suggest that a technique of local RES stimulation could have a place in preparation of certain high-risk patients for elective abdominal surgery where peritoneal contamination is likely.

Treatment of rat fibrosarcoma by radiotherapy plus immune adjuvant

Combined radiotherapy and nonspecific adjuvant C. parvum or Piromen treatment of rat tumors show improvement over radiotherapy alone. The most effective protocol, resulting in complete remission in 6 of 6 rats was obtained with C. parvum given i.p. in three doses 1 day prior to tumor X-irradiation of three doses of 1500 R each given on days 1, 4, and 8. Animals receiving the same dose schedule without adjuvant had only partial regression of their tumor. Without adjuvant, increasing the dose to 6000 R also resulted in tumor regression, but at the expense of marked necrosis to the leg. One mechanism for the observed results may be stimulation of the reticulo-endothelial system to produce macrophages activated against the tumor. It is also possible that C. parvum causes increased rate of clearance of soluble antigens released as a result of radiation destruction of the tumor, as suggested by Proctor et al (3).

Prevention of acute immunological lung lesion in rats by decomplementing treatment

The intravenous administration of nephrotoxic antibody serum to rats produced a rapid and pronounced reduction in the serum complement level; this was observed before lung lesions became apparent.

A total suppression of the acute immune lung change was observed in animals depleted of complement by treatment with heat-aggregated human γ-globulin or zymosan.

Albeit the experimental evidence presented is of indirect nature, it suggests that the complement system is involved in the mediation of the acute pulmonary injury following injection of nephrotoxic antibody serum.