Treatment of chemotherapy-induced leukopenia in a rat model with aqueous extract from Uncaria tomentosa.

The Uncaria tomentosa water extracts (C-Med-100) depleted of indole alkaloids (< 0.05%, w/w) have been shown to induce apoptosis and inhibit proliferation in tumor cells in vitro and to enhance DNA repair, mitogenic response and white blood cells in vivo. In this study, the effect of C-Med-100 in the treatment of chemically induced leukopenia was evaluated in a rat model. W/Fu rats were treated first with doxorubicin (DXR) 2 mg/kg x 3 (i.p. injection at 24 hour-intervals) to induce leukopenia. Twenty-four hours after the last DXR treatment, the rats were daily gavaged with C-Med-100 for 16 consecutive days. As a positive control, Neupogen, a granulocyte colony stimulator was also administered by subcutaneous injection at a dose of 5 and 10 microg/ml for 10 consecutive days. The results showed that both C-Med-100 and Neupogen treatment groups recovered significantly sooner (p < 0.05 by Duncan test) than DXR group. However, the recovery by C-Med-100 treatment was a more natural process than Neupogen because all fractions of white blood cells were proportionally increased while Neupogen mainly elevated the neutrophil cells. These results were also confirmed by microscopic examination of the blood smears. The mechanism of the C-Med-100 effect on WBC is not known but other data showing enhanced effects on DNA repair and immune cell proliferative response support a general immune enhancement.

Dietary lutein stimulates immune response in the canine.

The possible immuno-modulatory action of dietary lutein in dogs is not known. Female Beagle dogs (17-18-month old; 11.4+/-0.4kg body weight) were supplemented daily with 0, 5, 10 or 20mg lutein for 12 weeks. Delayed-type hypersensitivity (DTH) response to saline, phytohemagglutinin (PHA) and a polyvalent vaccine was assessed on Weeks 0, 6 and 12. Blood was sampled on Weeks 0, 2, 4, 8 and 12 to assess (1) lymphocyte proliferative response to PHA, concanavalin A (Con A), and pokeweed mitogen (PWM), (2) changes in peripheral blood mononuclear cell (PBMC) populations, (3) interleukin-2 (IL-2) production and (4) IgG and IgM production. After the completion of 12-week study, we continued to collect the blood weekly up to 17 weeks to evaluate the changes in immunoglobulin production upon first and second antigenic challenges on Weeks 13 and 15. Plasma lutein+zeaxanthin was undetectable in unsupplemented dogs but concentrations increased (P<0.05) rapidly on Week 2 in lutein-supplemented dogs. Thereafter, concentrations generally continued to increase in dose-dependent manner, albeit at a much slower rate. Dogs fed lutein had heightened DTH response to PHA and vaccine by Week 6. Dietary lutein increased (P<0.05) lymphocyte proliferative response to all three mitogens and increased the percentages of cells expressing CD5, CD4, CD8 and major histocompatibility complex class II (MHC II) molecules. The production of IgG increased (P<0.05) in lutein-fed dogs after the second antigenic challenge. Lutein did not influence the expression of CD21 lymphocyte marker, plasma IgM or IL-2 production. Therefore, dietary lutein stimulated both cell-mediated and humoral immune responses in the domestic canine.

Effect of dietary vitamin E supplementation on murine nasal allergy.

BACKGROUND: Although many studies have reported the effects of dietary vitamin E on the immune response, none so far has assessed its role in nasal allergy. METHODS: Female BALB/c mice were randomized into two groups and fed a 20% casein diet (control group, 50 mg vitamin E/kg diet) or this diet supplemented with 535 mg vitamin E/kg diet (vitamin E group, 585 mg vitamin E/kg diet) for 4 weeks. During the fifth week, the mice in each group were divided into two subgroups to form a total of four treatment groups: group A (control), group B [control + toluene diisocyanate (TDI) sensitization], group C (vitamin E supplementation), and group D (vitamin E supplementation + TDI sensitization). Groups B and D were treated with two courses of intranasal application of 5% TDI in ethyl acetate, whereas groups A and C were treated with ethyl acetate alone. A week after second sensitization all groups were provoked by applying 2.5% of TDI in the vehicle and nasal allergic responses were observed for 10 minutes. Splenic lymphoproliferation, splenic cell cytokines, and the total serum IgE were measured. RESULTS: Members of group D had lower (P < 0.01) scores of nasal response and sneezed less frequently (P < 0.01) than those of group B. Similarly, splenic lymphoproliferation and production of IL-4 and IL-5 as well as the total serum IgE levels were lower (P < 0.01) in group D than in group B. CONCLUSIONS: The results indicate that higher doses of vitamin E supplementation may suppress nasal allergic responses.

Effects of carbon dioxide inhalation on hematology, coagulation, and serum clinical chemistry values in rats.

Blood samples from adult male and female Charles River Crl:CD (SD) BR rats were collected at weekly intervals for 4 wk to evaluate the effects of inhalation of an anesthetic dose of carbon dioxide (CO2) or of a carbon dioxide-oxygen mixture (CO2/O2) on hematology, coagulation, and serum biochemistry values. During the first 3 wk of the study, rats were assigned to 1 of 3 groups and were bled from the orbital sinus once weekly. Prior to the blood collection, rats in group 1 were exposed to room air only, rats in group 2 received CO2/O2 (approximately 66%:34% CO2:O2) by inhalation, and rats in group 3 received 100% CO2 by inhalation. In the rats exposed to CO2/O2 or CO2, leukocyte counts, lymphocyte counts, and glucose values were higher, and aspartate aminotransferase, creatine kinase, and calcium values were lower compared with those of rats exposed to room air only. Rats exposed to 100% CO2 had slightly (but statistically significant) lower mean corpuscular hemoglobin concentration when compared with rats exposed only to room air. During week 4, all rats were reassigned to 1 of 2 groups and were bled terminally via closed cardiac puncture following exposure to either CO2/O2 or CO2. Increased lymphocyte counts (males only) and glucose and chloride concentrations were noted for rats exposed to CO2/O2 compared with those exposed to CO2. These alterations reiterate the importance of comparing clinical pathology values to those of concurrent control groups that have experienced blood collection under identical conditions in order to avoid potential errors in the interpretation of data.

Reduced bcl-2 concentrations in hypertensive patients after lisinopril or nifedipine administration.

In 30 patients with essential hypertension and 30 healthy control subjects, we evaluated blood concentrations of B cell leukemia-2 (bcl-2), a protooncogene that can reduce apoptosis. Bcl-2 concentrations were higher in hypertensive than in normotensive subjects. The increase in pressure due to a cold pressor test caused a further increase in blood bcl-2 concentrations, in both hypertensive and normotensive subjects. Treatment of hypertensive patients with hypotensive drugs caused a reduction in bcl-2 concentrations, which was more marked after administration of lisinopril than of nifedipine. The results suggest that concentrations of bcl-2 are increased in patients with hypertension, which could be an important factor in cell proliferation underlying posthypertensive vascular remodeling. Moreover, lisinopril and nifedipine appear to be capable of reducing bcl-2 concentrations, with potentially beneficial effects on vascular modifications in patients with hypertension.

Effects of soybean oil emulsion and eicosapentaenoic acid on stress response and immune function after a severely stressful operation.

OBJECTIVE: To investigate the effects of soybean oil emulsion and oral or enteral administration of eicosapentaenoic acid (EPA) on stress response, cytokine production, protein metabolism, and immune function after surgery for esophageal cancer. SUMMARY BACKGROUND DATA: It has been reported that safflower oil, rich in n-6 polyunsaturated fatty acid (n-6 PUFA), affects the survival rate of septic animals and decreases the immune function. It has also been reported that the administration of fish oil, in contrast, reduces these stress responses and stress-induced immunosuppression. In humans, the effects of soybean oil emulsion and the administration of EPA on stress response and immune function after surgery have not been established. METHODS: Patients who underwent esophagectomy with thoracotomy were divided into three groups. Seven patients were fed by total parenteral nutrition (TPN) with soybean oil emulsion, which accounted for 20% of total calories. Seven patients were given oral or enteral administration of 1.8 g/day EPA, in addition to TPN with soybean oil emulsion. Nine patients served as the control group; these patients received fat-free TPN. Serum interleukin-6 (IL-6), C-reactive protein, concanavalin A (con A)- or phytohemagglutinin (PHA)-stimulated lymphocyte proliferation, natural killer cell activity, and stress hormones were measured. RESULTS: The postoperative level of serum IL-6 was significantly higher in the group receiving soybean oil emulsion than in the fat-free group. Oral or enteral supplementation of EPA with soybean oil emulsion significantly reduced the level of serum IL-6 compared with the patients receiving soybean oil emulsion. Con A- or PHA-stimulated lymphocyte proliferation decreased significantly on postoperative day 7 in all groups of patients. The supplementation of EPA with soybean oil emulsion significantly improved the lymphocyte proliferation and natural killer cell activity on postoperative day 21 compared with the group receiving soybean oil emulsion. CONCLUSIONS: Soybean oil emulsion amplifies, and the supplementation of EPA reduces, the stress response and stress-induced immunosuppression.

Effects of glutamine supplementation on circulating lymphocytes after bone marrow transplantation: a pilot study.

Glutamine (Gln) is an important nutrient substrate for lymphocytes and macrophages in vitro. This pilot study evaluated effects of Gln supplementation on circulating lymphocytes and lymphocyte subsets after allogeneic bone marrow transplantation (BMT). Adult patients received either parenteral nutrition supplemented by L-Gln (Gln-PN) or standard Gln-free PN after BMT. Leukocyte and total lymphocyte counts were determined during hospitalization, and flow cytometry studies of peripheral mononuclear cells were performed 1 to 2 weeks after hospital discharge. The Gln-PN group demonstrated a higher percentage of blood lymphocytes during hospitalization. At flow cytometry, patients who received Gln-PN had an increased total lymphocyte count (332 +/- 50 versus 590 +/- 71 cells/microL, P = 0.010); greater numbers of total T lymphocytes (54 +/- 19 versus 229 +/- 70 cells/microL, P = 0.030); and higher CD4+ and CD8+ T-lymphocyte counts in peripheral blood compared with controls. Gln-PN may support lymphocyte recovery after BMT.

Immunomodulating efficacy of combined administration of galactoside-specific lectin standardized mistletoe extract and sodium selenite in BALB/c-mice.

The immunomodulating abilities of commercially available mistletoe extract standardized for the galactoside-specific lectin (mistletoe lectin-1, ML-1) and sodium selenite (Se) were evaluated in BALB/c-mice and compared to non-treated control animals. Following the optimal schedule of administration (ML-1: 1ng/kg BW; days 1, 2, 3, 5 and Se: 3,5 micrograms/kg BW for 7 subsequent days before evaluation) yielded enhanced counts (thymocytes; peritoneal macrophages, MO; peripheral blood leukocytes; lymphocytes, PBL; monocytes, PBM) and activities (CD-25 positive PBL, MAC-3 positive PBM) of desired immune cells reaching statistical significance for most parameters. However, combined administration of ML-1 and Se proved to be superior to monotherapy since immune cell counts (thymocytes, leukocytes, PBL, PBM) and activities (CD-25 positive PBL) exceeded values obtained after monotherapy. These data are in favour of therapeutical strategies in complementary oncology and suggest that the combination of defined immunomodulating substances might positively enhance the efficacy.

Effects of dietary arachidonic acid on human immune response.

Arachidonic acid (AA) is a precursor of eicosanoids, which influence human health and the in vitro activity of immune cells. We therefore examined the effects of dietary AA on the immune response (IR) of 10 healthy men living at our metabolic suite for 130 d. All subjects were fed a basal diet containing 27 energy percentage (en%) fat, 57 en% carbohydrate, and 16 en% protein (AA, 200 mg/d) for the first and last 15 d of the study. Additional AA (1.5 g/d) was incorporated into the diet of six men from day 16 to 65 while the remaining four subjects continued to eat the basal diet. The diets of the two groups were crossed-over from day 66 to 115. In vitro indexes of IR were examined using the blood samples drawn on days 15, 58, 65, 108, 115, and 127. The subjects were immunized with the measles/mumps/rubella vaccine on day 35 and with the influenza vaccine on day 92. Dietary AA did not influence many indexes of IR (peripheral blood mononuclear cell proliferation in response to phytohemagglutinin, Concanavalin A, pokeweed, measles/mumps/rubella, and influenza vaccines prior to immunization, and natural killer cell activity). The post-immunization proliferation in response to influenza vaccine was about fourfold higher in the group receiving high-AA diet compared to the group receiving low-AA diet (P = 0.02). Analysis of variance of the data pooled from both groups showed that the number of circulating granulocytes was significantly (P = 0.03) more when the subjects were fed the high-AA diet than when they were fed the low-AA diet. The small increases in granulocyte count and the in vitro proliferation in response to influenza vaccine caused by dietary AA may not be of clinical significance. However, the lack of any adverse effects on IR indicates that supplementation with AA may be done safely when needed for other health reasons.

Citicoline improves memory performance in elderly subjects.

Citicoline is a choline donor involved in the biosynthesis of brain phospholipids and acetylcholine extensively used in the treatment of neurodegenerative diseases. In this study we investigated the effects of the oral administration of citicoline alone (C1000:1000 mg/day; C500:500 mg/day) or in combination with nimodipine (C +NI:300 + 90 mg/day) during 4 weeks on memory performance in elderly subjects with memory deficits and without dementia (N = 24; age = 66.12 +/- 10.78 years; MMS score = 31.69 +/- 2.76). Results indicated that citicoline in comparison with placebo improves memory in free recall tasks, but not in recognition tests. A significant improvement in word recall (5.17 +/- 1.1 vs. 3.95 +/- 1.2 omissions; p < 0.005), immediate object recall (6.5 +/- 1.6 vs. 5.5 +/- 1.2 omission; p < 0.05) and delayed object recall (8.5 +/- 2.1 vs. 6.7 +/- 2.4 omissions; p < 0.005) was observed after citicoline treatment. Similar results were found in the three subgroups of treatment (8 subjects per group), suggesting that citicoline possesses memory-enhancing activity at doses of 300-1000 mg/day. A decrease in systolic blood pressure and minor changes in lymphocyte cell counting were also observed in old subjects after receiving citicoline. These effects are consistent with the vasoregulatory and neuroimmune actions of citicoline and suggest that this compound may improve memory by acting on mechanisms of brain neurotropism and cerebrovascular regulation. According to the present results, showing that citicoline improves memory performance in elderly subjects, we concluded that this molecule is suitable for the treatment of memory deficits in old people.

Feed intake, body weight, body condition score, musculation, and immunocompetence in aged mares given equine somatotropin.

Sixteen 20- to 26-yr-old mares were given 0, 6.25, or 12.5 mg/d equine somatotropin (eST) to determine whether aged mares respond to ST with changes in feed intake, body weight, body condition score (based mostly on fat cover), or immunocompetence. Neither dry matter intake, body weight, nor body condition scores were altered during the 6 wk of eST injection. However, based on photographs taken to evaluate musculation before and after treatment (scores 0 to 4), mares given eST developed greater (P < .07) muscle definition (1.8 +/- .6 and 2.5 +/- .6 for 6.25 and 12.5 mg eST/d, respectively) than control mares (.7 +/- .4). Total circulating leukocytes increased (P < .05) in both of the eST-treated groups during the 6-wk injection period, caused by an increase (P < .05) in granulocytes. Lymphocyte numbers were not altered. Granulocyte oxidative burst activity was not altered by eST treatment. Although lymphocyte proliferative responses to phytohemagglutinin, pokeweed mitogen, or lipopolysaccharide were not altered during the treatment period, lymphocyte proliferation in response to phytohemagglutinin and pokeweed mitogen increased twofold in eST-treated horses at 2 wk after eST treatment. In overview, the increased musculation and the increase in granulocyte numbers in mares given eST suggest that eST supplementation may improve the health and well-being of aged mares.

Immunomodulatory effects of NIM-76, a volatile fraction from Neem oil.

The immunomodulatory properties of NIM-76 have been described in this paper. Pre-treatment of rats with a single i.p. injection of NIM-76 resulted in an increase in polymorphonuclear (PMN) leukocytes with a concomitant decrease in lymphocyte counts. The immunomodulatory activity of NIM-76 was found to be concentration-dependent. At 120 mg/kg body weight, there was an enhanced macrophage activity and lymphocyte proliferation response, while the humoral component of immunity was unaffected. At higher concentrations of NIM-76 (300 mg/kg body weight), there was a stimulation of mitogen-induced lymphocyte proliferation, while macrophage activity remained unaffected. However, a fall in primary and secondary antibody titres was observed. The study indicates that NIM-76 acts through cell-mediated mechanisms by activating macrophages and lymphocytes.

Academic examinations significantly impact immune responses, but not lung function, in healthy and well-managed asthmatic adolescents.

The influence of academic examinations on immunity and lung function was investigated in 64 adolescents to determine if stress-related changes would differ between healthy and asthmatic students. Blood samples were collected on three occasions: 1 month prior, during, and 2-3 weeks after exams. Leukocyte subsets were enumerated, and in vitro assays were conducted to assess lymphocyte proliferative and cytolytic responses and neutrophil production of superoxides. Examinations elicited significant changes in several lymphocyte subsets and marked alterations in the three functional measures in all students. However, the magnitude and pattern of change did not differ between healthy and asthmatic students. Similarly, neither mild nor more severe asthmatics showed an exam-related decrement in lung function, as reflected by peak expiratory flow rate. This research validated that examinations are a salient cause of altered immune responses, but indicates that there is not a concomitant aggravation of inflammatory disease in well-managed asthmatics.

Effect of radon on the immune system: alterations in the cellularity and functions of T cells in lymphoid organs of mouse.

Exposure to radon and its progeny induces significant damage to the cells of the respiratory tract and causes lung cancer. Whether a similar exposure to radon would alter the functions of the immune system has not been previously investigated. In the current study, we investigated the effect of exposure of C57BL/6 mice to 1000 or 2500 working-level months (WLM) of radon and its progeny by inhalation, on the number and function of T lymphocytes in lymphoid organs. The control mice received uranium ore dust carrier aerosol by inhalation. Exposure to radon induced marked decrease in the total cellularity of most lymphoid organs such as thymus, peripheral lymph nodes (PLN), and lung-associated lymph nodes (LALN), when compared to the controls. The percentage of T cells increased, while that of non-T cells decreased, in all peripheral lymphoid organs at both the doses of radon. In the thymus, particularly at 2500 WLM of radon exposure, there was a marked decrease in CD4+CD8+ T cells and an increase in the immature CD4-CD8- T cells. Such alterations in both the numbers and percentages of lymphocytes and macrophages in radon-exposed mice may have resulted from the cell killing by the alpha particles as the immune cells were migrating through the lungs, or it may have been caused by altered migration of cells, inasmuch as expression of CD44, a molecule involved in migration and homing of immune cells, was significantly altered on cells found in different lymphoid organs. In the LALN, where one would predict the largest number of damaged cells to be present, there was a significant decrease in the T-cell responsiveness to mitogens while the B-cell response was not affected. Such alterations may have resulted from the direct effect of alpha-particle exposure on the migrating lymphocytes, altered percentage of lymphocytes as seen in secondary lymphoid organs, or altered expression of adhesion molecules involved in cell activation such as CD44 and CD3. Interestingly, radon exposure caused and increase in the T- and B-cell responsiveness to mitogens in the spleen and PLN. Since there is little evidence of direct radiation dose from radon in lymphoid organs, our studies demonstrating immunological alterations suggest an indirect effect of radon exposure that may have significant repercussions on the development of hypersensitivity and increased susceptibility to infections and cancer in the lung.

Experiences with an advanced screening procedure for the identification of chemicals with an immunotoxic potential in routine toxicology.

The development or selection of suitable tests for immunotoxicological screening and thus for incorporation into guidelines presents some problems. Most of the tests which have been proposed for immunotoxicological investigations and most knowledge and experience in immunology are based on mouse models. The standard species in the early phase of toxicological testing, however, is the rat. Any discussion about basic tests is hampered by a paucity of data from routine toxicological and/or epidemiological studies. Here we present data obtained from an advanced screening battery on the basis of OECD guideline 407. Thirteen pesticides of early development stage had been included in this screening. Two out of these 13 compounds turned out to be cytotoxic and were picked up by the immunological parameters as being 'primary immunotoxic', i.e., immunological changes not induced by overtly toxic doses ('indirect or secondary immunotoxic'). The advantages and disadvantages of each additional test is discussed as well as the comparison of the results obtained on the basic and the extended guideline test battery. In summary, the tests described here show that a little extra effort at the screening stage can save animals, time and costs for additional testing.

Immunomodulating ability of galactoside-specific lectin standardized and depleted mistletoe extract.

Commercially available mistletoe extract standardized for the galactoside-specific lectin (ML-1; Eurixor) and a chromatographically ML-1-depleted preparation (same charge no. and composition of remaining components) were tested for their immunomodulating potency. In BALB/c-mice, regular subcutaneous administration of the optimal immunomodulating dosage (1 ng ML-1/kg body weight) could be shown to induce no influence on spleen weight, a non-significant increase of thymus weight, a significant increase of thymocyte, peritoneal macrophage, peripheral blood leukocyte, lymphocyte and monocyte and monocyte counts, and a significant decrease of peripheral blood granulocyte counts. Administration of analogue volumes (concentrations) of ML-1-depleted extract, however, did not induce any immunopotentiation. Accordingly, it may be assumed, that the galactoside-specific lectin (ML-1) represents the main immunomodulating component in commercially available mistletoe extracts.

T-cell responses in photoimmune therapy.

The extracorporeal inactivation of a lymphocyte rich buffy coat suspension with ultraviolet A light and 8 methoxypsoralen can lead to dramatic clinical improvements following reinfusion of the damaged cells. This therapy is reviewed in the context of the disease it is most commonly used for: cutaneous lymphoma. Studies with cutaneous lymphoma patients have shown an active immune response against purified tumor cells. In addition a mouse model for an impact of therapy on a T-cell lymphoma has demonstrated results that parallel those from clinical studies in humans. The impact of photoimmune therapy on in vivo and in vitro T-cell responses to cutaneous lymphoma is discussed.

Ex vivo evaluation of pidotimod activity on cell-mediated immunity.

The activity of pidotimod ((R)-3-[(S)-(5-oxo2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) on immunological parameters was evaluated in a double-blind trial, involving two Research Centres. 16 patients with a primary or metastatic neoplasm, 16 elderly patients under immunodeficiency conditions and 11 healthy volunteers were enrolled in the present study. The patients, randomized within each centre, were assigned to one of the following treatments lasting 15 days: one vial i.m. of pidotimod 50 mg, 100 mg, 200 mg twice a day, respectively; one vial i.m. of physiological saline twice a day. The lymphocyte PHA-stimulation test evidenced a significant variability due to the different treatment groups (p = 0.004). The analysis of the stimulation index (SI), computed from the mean c.p.m. before and after PHA-stimulation, showed a significant difference, dose-independent, between saline and active treatment (p = 0.002). The SI analysis, on the basis of the data of the allogenic stimulation test (mixed lymphocyte culture), confirmed the difference between saline and active treatment (p = 0.05) with a significant linear component in the time-effect curve (p = 0.001) but not in the dose-effect curve. A 12% increase in CD 3 lymphocytes compartment was observed with pidotimod 400 mg/day. The drug was well tolerated by all the patients included in the study.