Can Lacticaseibacillus rhamnosus CRL1505 postbiotic improve emergency myelopoiesis in immunocompromised mice?

We evaluated whether viable and non-viable Lacticaseibacillus rhamnosus CRL1505 (Lr05V or Lr05NV, respectively) was able to improve emergency myelopoiesis induced by Streptococcus pneumoniae (Sp) infection. Adult Swiss-mice were orally treated with Lr05V or Lr05NV during five consecutive days. The Lr05V and Lr05NV groups and untreated control group received an intraperitoneal dose of cyclophosphamide (Cy-150 mg/kg). Then, the mice were nasally challenged with Sp (107 UFC/mice) on day 3 post-Cy injection. After the pneumococcal challenge, the innate and myelopoietic responses were evaluated. The control group showed a high susceptibility to pneumococcal infection, an impaired innate immune response and a decrease of hematopoietic stem cells (HSCs: Lin-Sca-1+c-Kit+), and myeloid multipotent precursors (MMPs: Gr-1+Ly6G+Ly6C-) in bone marrow (BM). However, lactobacilli treatments were able to significantly increase blood neutrophils and peroxidase-positive cells, while improving cytokine production and phagocytic activity of alveolar macrophages. This, in turn, led to an early Sp lung clearance compared to the control group. Furthermore, Lr05V was more effective than Lr05NV to increase growth factors in BM, which allowed an early HSCs and MMPs recovery with respect to the control group. Both Lr05V and Lr05NV were able to improve BM emergency myelopiesis and protection against respiratory pathogens in mice undergoing chemotherapy.

Improvement of Myelopoiesis in Cyclophosphamide-Immunosuppressed Mice by Oral Administration of Viable or Non-Viable Lactobacillus Strains.

Myelosuppression is the major dose-limiting toxicity of cancer chemotherapy. There have been many attempts to find new strategies that reduce myelosuppression. The dietary supplementation with lactic acid bacteria (LAB) improved respiratory innate immune response and the resistance against respiratory pathogens in immunosupressed hosts. Although LAB viability is an important factor in achieving optimal protective effects, non-viable LAB are capable of stimulating immunity. In this work, we studied the ability of oral preventive administration of viable and non-viable Lactobacillus rhamnosus CRL1505 or L. plantarum CRL1506 (Lr05, Lr05NV, Lp06V or Lp06NV, respectively) to minimize myelosuppressive and immunosuppressive effects derived from chemotherapy. Cyclophosphamide (Cy) impaired steady-state myelopoiesis in lactobacilli-treated and untreated control mice. Lr05V, Lr05NV and Lp06V treatments were the most effective to induce the early recovery of bone marrow (BM) tissue architecture, leukocytes, myeloid, pool mitotic and post-mitotic, peroxidase positive, and Gr-1Low/High cells in BM. We selected the CRL1505 strain for being the one capable of maintaining its myelopoiesis-enhancing properties in its non-viable form. Although the CRL1505 treatments do not modify the Cy ability to induce apoptosis, both increased the incorporation of BrdU in BM cells. Consequently, Lr05NV and Lr05V treatments were able to promote early recovery of LSK cells (Lin-Sca-1+c-Kit+ cells), multipotent progenitors (Lin-Sca-1+c-Kit+CD34+ cells), and myeloid cells (Gr-1+Ly6G+Ly6C- cells) with respect to the untreated Cy control. In addition, these treatments were able to increase the frequency of IL17A-producing innate lymphoid cells in the intestinal lamina propria (IL-17A+RORγt+CD4-NKp46+ cells) after Cy injection. These results were correlated with an increase in the IL-17A serum levels, a GM-CSF high expression and a CXCL12 lower expression in BM. Therefore, both Lr05V and Lr05NV treatments are able to activate beneficially the IL-17A/GM-CSF axis and accelerate the recovery of Cy-induced immunosuppression by increasing BM myeloid precursors. We demonstrated for the first time the beneficial effect of CRL1505 strain on myelopoiesis affected by a chemotherapeutic drug. Furthermore, Lr05NV could be a good and safe resource for reducing chemotherapy-induced leukopenia. The results are a starting point for future research and open up broad prospects for future applications of the immunobiotics.

El Sodium caseinate and alfa-casein inhibit proliferation of the mouse myeloid cell line 32D clone 3 (32Dcl3) via TNF-α / El caseinato de sodio y la caseína α inhiben la proliferación de la línea celular mieloide de ratón 32D clone 3 (32Dcl3) mediante el TNF-α.

Introduction: Sodium caseinate (CS) and its components (alpha-casein, beta-casein, and kappa-casein) have been shown to inhibit the proliferation of the mouse hematopoietic 32D clone 3 (32Dcl3) cell line and induce its differentiation into macrophages. It is well-known that alpha-casein induces IL-1ß production and that this cytokine inhibits the proliferation via the production of tumor necrosis factor alpha (TNF-alpha), but it is not known if CS and the caseins inhibit the proliferation via TNF-alpha production. Objective: To evaluate if CS and alpha-casein, beta-casein and kappa-casein inhibit the proliferation on 32Dcl3 cell line via TNF-alpha. Materials and methods: We used different concentrations of CS, alpha-casein, betacasein and kappa-casein in 32Dcl3 cells to evaluate cell proliferation. We assessed cell viability by MTT, induction to apoptosis by flow cytometry, and TNF-alpha synthesis by ELISA. Additionally, we performed anti-TNF-alpha neutralization assays on 32Dcl3 cells treated with CS and alpha-casein and we evaluated proliferation. Results: The results showed that CS, alpha-casein, beta-casein, and kappa-casein reduced proliferation of the 32Dcl3 cell line without affecting the viability and that only CS and alpha-casein induced apoptosis and the release of TNF-alpha. The 32Dcl3 cells treated with CS and alpha-casein reestablished their proliferation by using anti-TNF-alpha antibodies. Conclusion: TNF-alpha was the main responsible for the inhibition of proliferation in 32Dcl3 cells treated with CS or alpha-casein.

Introducción. Se ha demostrado que el caseinato de sodio y sus componentes (caseínas α, ß y κ) inhiben la proliferación de la línea celular hematopoyética de ratón 32D clone 3 (32Dcl3) e inducen su diferenciación hacia macrófagos. Se sabe que la caseína α induce la producción de IL-1ß y que esta última citocina inhibe la proliferación celular mediante la producción del factor de necrosis tumoral alfa (TNF-α), pero se desconoce si el caseinato de sodio y las caseínas inducen la producción de TNF y si este es el responsable de la inhibición de la proliferación. Objetivo. Evaluar si el caseinato de sodio y las caseínas α, ß y κ inhiben la proliferación de la línea celular 32Dcl3 mediante la producción de TNF-α. Materiales y métodos. Se usaron diferentes concentraciones de caseinato de sodio y de las caseínas α, ß y κ en las células 32Dcl3. Posteriormente, se evaluaron la viabilidad celular mediante una prueba con el MTT [3-(4,5-dimetiltiazol-2-ilo)-2,5-difeniltetrazol], la inducción de apoptosis con la citometría de flujo y la síntesis del TNF-α con el ELISA. Además, se hicieron pruebas de neutralización con anti-TNF-α en células 32Dcl3 tratadas con caseinato de sodio y caseína α, y se evaluó la proliferación celular. Resultados. Se encontró que el caseinato de sodio y las caseínas α, ß y κ reducían la proliferación de la línea celular 32Dcl3 sin afectar la viabilidad, y que solo el caseinato y la caseína α inducían la apoptosis y la liberación al medio de TNF-α. La proliferación de células 32Dcl3 tratadas con caseinato y caseína α se restableció al usar anticuerpos anti-TNF-α. Conclusión. El TNF-α fue el principal responsable de la inhibición de la proliferación en las células 32Dcl3 tratadas con caseinato de sodio o caseína α.

El caseinato de sodio y la caseína α inhiben la proliferación de la línea celular mieloide de ratón 32D clone 3 (32Dcl3) mediante el TNF-α / Sodium caseinate and alfa-casein inhibit proliferation of the mouse myeloid cell line 32D clone 3 (32Dcl3) via TNF-α

Resumen Introducción. Se ha demostrado que el caseinato de sodio y sus componentes (caseínas α, β y κ) inhiben la proliferación de la línea celular hematopoyética de ratón 32D clone 3 (32Dcl3) e inducen su diferenciación hacia macrófagos. Se sabe que la caseína α induce la producción de IL-1β y que esta última citocina inhibe la proliferación celular mediante la producción del factor de necrosis tumoral alfa (TNF-α), pero se desconoce si el caseinato de sodio y las caseínas inducen la producción de TNF y si este es el responsable de la inhibición de la proliferación. Objetivo. Evaluar si el caseinato de sodio y las caseínas α, β y κ inhiben la proliferación de la línea celular 32Dcl3 mediante la producción de TNF-α. Materiales y métodos. Se usaron diferentes concentraciones de caseinato de sodio y de las caseínas α, β y κ en las células 32Dcl3. Posteriormente, se evaluaron la viabilidad celular mediante una prueba con el MTT [3-(4,5-dimetiltiazol-2-ilo)-2,5-difeniltetrazol], la inducción de apoptosis con la citometría de flujo y la síntesis del TNF-α con el ELISA. Además, se hicieron pruebas de neutralización con anti-TNF-α en células 32Dcl3 tratadas con caseinato de sodio y caseína α, y se evaluó la proliferación celular. Resultados. Se encontró que el caseinato de sodio y las caseínas α, β y κ reducían la proliferación de la línea celular 32Dcl3 sin afectar la viabilidad, y que solo el caseinato y la caseína α inducían la apoptosis y la liberación al medio de TNF-α. La proliferación de células 32Dcl3 tratadas con caseinato y caseína α se restableció al usar anticuerpos anti-TNF-α. Conclusión. El TNF-α fue el principal responsable de la inhibición de la proliferación en las células 32Dcl3 tratadas con caseinato de sodio o caseína α.

Abstract Introduction: Sodium caseinate (CS) and its components (alpha-casein, beta-casein, and kappa-casein) have been shown to inhibit the proliferation of the mouse hematopoietic 32D clone 3 (32Dcl3) cell line and induce its differentiation into macrophages. It is well-known that alpha-casein induces IL-1β production and that this cytokine inhibits the proliferation via the production of tumor necrosis factor alpha (TNF-alpha), but it is not known if CS and the caseins inhibit the proliferation via TNF-alpha production. Objective: To evaluate if CS and alpha-casein, beta-casein and kappa-casein inhibit the proliferation on 32Dcl3 cell line via TNF-alpha. Materials and methods: We used different concentrations of CS, alpha-casein, beta-casein and kappa-casein in 32Dcl3 cells to evaluate cell proliferation. We assessed cell viability by MTT, induction to apoptosis by flow cytometry, and TNF-alpha synthesis by ELISA. Additionally, we performed anti-TNF-alpha neutralization assays on 32Dcl3 cells treated with CS and alpha-casein and we evaluated proliferation. Results: The results showed that CS, alpha-casein, beta-casein, and kappa-casein reduced proliferation of the 32Dcl3 cell line without affecting the viability and that only CS and alpha-casein induced apoptosis and the release of TNF-alpha. The 32Dcl3 cells treated with CS and alpha-casein reestablished their proliferation by using anti-TNF-alpha antibodies. Conclusion: TNF-alpha was the main responsible for the inhibition of proliferation in 32Dcl3 cells treated with CS or alpha-casein.

Cancer-induced systemic myeloid dysfunction: Implications for treatment and a novel nanoparticle approach for its correction.

Unlike other regulatory circuits, cancer-induced myeloid dysfunction involves more than an accumulation of impaired dendritic cells, protumoral macrophages, and myeloid derived suppressor cells in the tumor microenvironment. It is also characterized by "aberrant" myelopoiesis that results in the accumulation and expansion of immature myeloid precursors with a suppressive phenotype in the systemic circulation. The first part of this review briefly describes the evidence for and consequences of this systemic dysfunctional myelopoiesis and the possible reinforcement of this phenomenon by conventional treatments used in patients with cancer, in particular chemotherapy and granulocyte-colony stimulating factor. The second half of this review describes very small size particles, a novel immune-modulatory nanoparticle, and the evidence indicating a possible role of this agent in correcting or re-programming the dysfunctional myelopoiesis in different scenarios.

Association of ABCB1, ABCC5 and xanthine oxidase genetic polymorphisms with methotrexate adverse reactions in Mexican pediatric patients with ALL.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is one of the most frequent oncological disorders in pediatric populations. To date, the drug of choice for the treatment of ALL is methotrexate, a drug associated with a high risk of adverse reactions (ADRs). The xanthine oxidase (XO) polymorphisms, 1936A>G and 2107A>G, as well as the polymorphic variants derived from ATP-binding cassette transporter gene subfamilies, ABCB1 and ABCC5, of drug resistant codifying genes, are implicated as precursors of drug-related neurologic, hepatic, and renal toxicities. Our aim was to determine whether the mentioned polymorphisms are risk or protective factors for the development of adverse reactions by methotrexate in our pediatric population with ALL. METHODS: A total of 35 Mexican children from Centro Estatal de Cancerología-Durango, Mexico, with ALL and the previously noted polymorphisms as determined qPCR were studied. At the same time, a 12-month drug monitoring program was conducted in accordance with WHO-PAHO guidelines for pharmacovigilance. RESULTS: The ABCB11936A>G and 2107A>G and ABCC5 3414+434A>C polymorphisms were not associated with methotrexate ADRs. Single nucleotide polymorphisms (SNPs) of ABCB1 1236C>T (OR 0.19, 95% CI: 0.03-0.9, p<0.05) and ABCC5 3933+313T>C (OR 0.12, 95% CI: 0.027-0.58, p<0.05) were associated with methotrexate ADRs. CONCLUSIONS: SNPs 1236C>T of ABCB1 and ABCC5 3933+313T>C are not associated with the development of typical ADRs by methotrexate, rather, they showed a protective factor for myelosuppression in the studied sick population.

Sodium caseinate induces mouse granulopoiesis.

OBJECTIVE AND DESIGN: Sodium caseinate (CasNa) induces differentiation and M-CSF production in mouse band granulocytes in vitro; however, it is not yet known if this molecule can also induce the proliferation and activation of the granulocyte lineage in vivo. In this work we evaluated the induction in vivo of granulopoiesis and the activation of granulocytes in mice treated with CasNa. MATERIAL OR SUBJECTS: BALB/c male mice 8-12 weeks old were used. TREATMENT: The animals were inoculated intraperitoneally with 1 ml of CasNa (10% in PBS p/v) four times (every 48 h). METHODS: Granulocyte proliferation was evaluated by flow cytometry; activation was evaluated by phagocytic indices. The cytokine was measured using an ELISA assay. RESULTS: We show that CasNa increased bone marrow granulopoiesis percentage (38.35 ± 10.88 vs. 64.94 ± 34.14 BrdU+/Gr-1+ cells) and the granulocytes generated presented increased phagocytic indices (0.3 ± 0.1 vs. 0.6 ± 0.11, p < 0.05). We also show that G-CSF (974 ± 411 vs. 3189 ± 350 pg/ml, p < 0.05) and GM-CSF increased in serum, but only G-CSF in bone marrow plasma. CONCLUSIONS: CasNa induces granulopoiesis with functional granulocytes, suggesting that this molecule could be an innate immune system activator.

Angelica sinensis modulates immunohematopoietic response and increases survival of mice infected with Listeria monocytogenes.

The effects of a dry extract of the roots of Angelica sinensis (Oliv.) Diels (ASE) on the growth and differentiation of granulocyte-macrophage progenitor cells (CFU-GM) in normal and Listeria monocytogenes-infected mice were studied. Myelosuppression concomitant with increased numbers of spleen CFU-GM was observed in infected mice. Prophylactic administration of ASE (10, 25, and 50 mg/kg) stimulated marrow myelopoiesis in a dose-dependent manner and reduced spleen colony formation to control values. The dose of 50 mg/kg ASE was the optimal biologically active dose in infected mice, and this dose schedule significantly increased survival of mice infected with a lethal dose of L. monocytogenes, with survival rate up to 30%. Investigation of the production of colony-stimulating factors revealed a dose-dependent increased colony-stimulating activity in the serum of infected mice, with higher response produced by the 50 mg/kg dose. Notably, no effects were observed with the 100 mg/kg dose, compared with infected nontreated controls. Further studies to investigate the production of factors such as inteferon-γ and tumor necrosis factor-α demonstrated increased levels of both cytokines in mice infected with L. monocytogenes and treated with 50 mg/kg ASE. We propose that ASE indirectly modulates immune activity and probably disengages Listeria-induced suppression of these responses by inducing a higher reserve of myeloid progenitors in the bone marrow in consequence of biologically active cytokine release (colony-stimulating factors, interferon-γ, and tumor necrosis factor-α).

Myelopoiesis modulation by ACE hyperfunction in kinin B(1) receptor knockout mice: relationship with AcSDKP levels.

Angiotensin I-converting enzyme (ACE), a common element of renin-angiotensin system (RAS) and kallikrein-kinin system (KKS), is involved in myelopoiesis modulation, mainly by cleaving the tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP). Based on this finding and in our results showing B1 and B2 kinin receptors expression in murine bone marrow (BM) cells, we evaluated the ACE influence on myelopoiesis of kinin B1 receptor knockout mice (B1KO) using long-term bone marrow cultures (LTBMCs). Captopril and AcSDKP were used as controls. Enhanced ACE activity, expressed by non-hematopoietic cells (Ter-199(-) and CD45(-)), was observed in B1KO LTBMCs when compared to wild-type (WT) cells. ACE hyperfunction in B1KO cells was maintained when LTBMCs from B1KO mice were treated with captopril (1.0microM) or AcSDKP (1.0nM). Although no alterations were observed in ACE mRNA and protein levels under these culture conditions, 3.0nM of AcSDKP increased ACE mRNA levels in WT LTBMCs. No alteration in the number of GM-CFC was seen in B1KO mice compared to WT animals, even when the former were treated with AcSDKP (10microg/kg) or captopril (100mg/kg) for 4 consecutive days. Hematological data also revealed no differences between WT and B1KO mice under basal conditions. When the animals received 4 doses of lipopolysaccharide (LPS), a decreased number of blood cells was detected in B1KO mice in relation to WT. We also found a decreased percentage of Gr1(+)/Mac-1(+), Ter119(+), B220(+), CD3(+), and Lin(-)Sca1(+)c-Kit(+) (LSK) cells in the BM of B1KO mice compared to WT animals. Low AcSDKP levels were observed in BM cultures from B1KO in comparison to WT cultures. We conclude that ACE hyperfunction in B1KO mice resulted in faster hydrolysis of AcSDKP peptide, which in turn decreased in BM tissues allowing HSC to enter the S stage of the cell cycle.

Comparative studies of the effects of Tabebuia avellanedae bark extract and beta-lapachone on the hematopoietic response of tumour-bearing mice.

The effects of Tabebuia avellanedae (TACE), traditionally prescribed in the treatment of cancer, and the naphtoquinone beta-lapachone (beta-lap) on the growth and differentiation of granulocyte and macrophage progenitor cells (CFU-GM) were studied in Ehrlich ascites tumour-bearing mice. Myelosuppression concomitant with increases in spleen CFU-GM and in serum colony-stimulating activity (CSA) were observed in these animals. Treatment with TACE (30-500 mg/kg) and beta-lap (1-5mg/kg) reversed these effects in a dose-dependent manner. The optimal biologically active doses of 120 mg/kg TACE and 1mg/kg beta-lap prolonged life span of tumour-bearing mice, both producing the same rate of extension in the duration of survival. Toxic manifestations were produced by the higher doses of beta-lap in normal and tumour-bearing mice. In spite of similarities between treatments, TACE concentrations used to treat the animals presented no traces of beta-lap, as measured by TLC and HPLC analyses. Our findings suggest that the antitumour effect of TACE and beta-lap, acting synergistically with other factors, such as specific cytokines, may result from enhanced macrophage activation against tumour cells. In addition, it is clear from our results that hematopoietic disorders produced by tumours are an important pathological condition that must be considered in drug development.

Antitumour activity of [1,2-di(cyclopentadienyl)-1,2-di(p-N,N-dimethylaminophenyl)-ethanediyl] titanium dichloride in xenografted Ehrlich's ascites tumour.

The effects of a new titanocene compound with an ansa ligand in the cyclopentadienyl rings, the 1,2-di(cyclopentadienyl)-1,2-di(p-N,N-dimethylaminophenyl)-ethanediyl] titanium dichloride (TITANOCENE X), on the growth and differentiation of granulocyte-macrophage progenitor cells [colony-forming unit-granulocyte-macrophage (CFU-GM)] and Natural killer (NK) cell activity in Ehrlich's ascites tumour (EAT)-bearing mice were studied. Myelosuppression concomitant with increased numbers of spleen CFU-GM was observed in tumour-bearing mice. Treatment of these animals with TITANOCENE X (2.5-50 mg/kg/day) produced an increase in myelopoiesis, in a dose-dependent manner, and reduced spleen colony formation. In addition, the treatment of EAT-bearing mice with 3 doses of 20 or 50 mg/kg TITANOCENE X restored to normal values the reduced Natural killer cell function observed during tumour growth. In parallel, TITANOCENE X prolonged, in a dose-dependent manner, the survival of mice inoculated with Ehrlich's ascites tumour. The highest dose of 50 mg/kg prolonged in 50% the survival time of EAT-bearing mice, compared to non-treated tumour-bearing controls. In comparison with previous results from our laboratory addressing the effects of titanocenes on haematopoiesis, we observed with TITANOCENE X a similar effective profile as for bis(cyclopentadienyl) dithiocyanate titanium(IV), being both less effective than di(cyclopentadienyl) dichloro titanium(IV), since the latter not only prolonged, but also increased the rate of survival. These differences in efficacy may be due to the nature of the ansa-cyclopentadienyl ligand used in TITANOCENE X, since the C2 bridge between the two cyclopentadienyl groups will increase the hydrolytic stability by an organometallic chelate effect. Also, the introduction of two dimethylamino substituents increases the water solubility of TITANOCENE X when compared to titanocene dichloride itself.

Euphorbia tirucalli L. modulates myelopoiesis and enhances the resistance of tumour-bearing mice.

Myelosuppression concomitant with increased numbers of spleen CFU-GM was observed in tumour-bearing mice. Treatment of these animals with Euphorbia tirucalli L. (ET) (125, 250 and 500 mg/kg) stimulated marrow myelopoiesis and reduced spleen colony formation, with no differences observed between the effects of the three doses. The changes produced by the tumour in total and differential marrow cell counts were restored by the treatment with ET. Prostaglandin E2 (PGE2) levels, which were dramatically increased in tumour bearers, was also abrogated by the treatment with the plant extract. Euphorbia tirucalli L. significantly enhanced survival and concurrently reduced tumour growth in the peritoneal cavity. We propose that the modulatory effect of Euphorbia tirucalli L. on myelopoietic response and on the levels of PGE2 may be related to its antitumour activity as a possible mechanism for the regulation of granulocyte and macrophage production and expression of functional activities.

Myelopoietic response in mice exposed to acute cold/restraint stress: modulation by Chlorella vulgaris prophylactic treatment.

In this study, hematopoietic cells from mice pretreated with CVE and exposed to acute cold/restraint stress were stimulated in the presence of growth factors to form colonies, thus providing accurate information about the modulation of the green algae of the stress-induced changes in the hematopoietic response. Our results demonstrated that exposure to acute stress affected hematopoiesis. Mice exposed for a 2.5-hour time period of cold and restraint presented diminished clonal capacity for CFU-GM content per femur, which was decreased by as much as 50% compared with that in control mice, in spite of the significant increase in serum colony-stimulating activity (CSA). Treatment with 50 mg/kg CVE for 5 days, previously to the stress regimen, attenuates the effects of the stress, since comparable levels of myeloid progenitors were found in the bone marrow of both CVE/stress and control mice. Moreover, the sera from stressed mice pretreated with CVE further increased the CFU-GM formation. On the contrary, the spleen seemed to be less sensitive to acute stress in our experimental conditions. These findings are in line with our previous reports showing that the stress-induced reduction in bone marrow CFU-GM of rats exposed to electric shocks is mediated by activation of the HPA axis and by secretion of opioid agonists. No changes were observed in bone marrow, spleen and thymus total cell counts, and in relative organ weights. However, a 50% reduction in the body weight loss produced by the stress was observed in mice given the extract.

Effects of amphetamine on immune-mediated lung inflammatory response in rats.

OBJECTIVE: The present study analyzed the effects of acute amphetamine (AMPH) treatment on immune-mediated lung inflammatory response in rats. METHODS: There were four experiments. In the first and second experiments, rats were treated with AMPH (1 mg/kg) or 0.9% NaCl, and locomotor activity (experiment 1) and serum AMPH concentrations (experiment 2) were measured 1 or 12 h after treatment. In the third experiment, rats which were immunized with ovalbumin (OVA) were treated 14 days later with 0.9% NaCl or AMPH (1 mg/kg). Twelve hours after these treatments, all animals were submitted to challenge by 1% OVA inhalation being analyzed afterwards for bronchoalveolar lavage fluid (BAL), peripheral blood and bone marrow cellularity. In the fourth and final experiment, rats were treated and studied as for experiment 3, except that half of the animals within each group were previously treated with metyrapone prior to the OVA challenge. RESULTS: In the non-immunized rats, AMPH treatment induced an increase in locomotor activity synchronized to high serum AMPH concentrations 1 h after, but not 12 h after treatment. In OVA-challenged rats, AMPH treatment decreased the total number of inflammatory cells, recovered in both BAL and peripheral blood and increased the total number of bone marrow cells. These effects, observed 1 day after OVA challenge, were abrogated by previous metyrapone treatment. CONCLUSION: AMPH treatment changed HPA-axis responsiveness to the stress condition imposed by the OVA challenge decreasing lung and blood leukocytes cellularity most probably via corticosterone actions on bone marrow activity.

Modulation by Acanthospermum australe extracts of the tumor induced hematopoietic changes in mice.

Previous studies on the Ehrlich ascites tumor (EAT) model indicate that tumor progression is associated with reduced myelopoiesis and increased extramedullar hematopoiesis. In order to investigate the in vivo antitumor activity of Acanthospermum australe, its hydroalcoholic extract was partitioned with different solvents and the resulting extracts were monitored by their effects on bone marrow and spleen hematopoietic progenitor cell proliferation and differentiation in EAT-bearing mice. Oral treatment of tumor-bearing mice with 3 doses of 100, 500 and 1000 mg/kg of the crude hydroalcoholic extract and its chloroformic, butanolic and aqueous fractions significantly stimulated myelepoiesis and brought extramedullar hematopoiesis back to near control values. In normal mice, stimulation of myelopoiesis was only observed with the crude and the butanolic extracts. All the extracts at 500 mg/kg significantly increased survival of tumor-bearing mice, however a clear survival advantage in the group treated with the butanolic extract was observed. These results suggest that A. australe may exert effects on myelopoiesis that may be implicated in antitumor immune responses.