beta-carotene and Leukemia

Conditioning therapy preceding bone marrow transplantation (BMT) usually consists of high-dose chemotherapy and total body irradiation (TBI). It has acute and delayed toxic effects on several tissues, possibly related to peroxidation processes and exhaustion of antioxidants. Early studies indicated an increase of peroxide processes and a decrease of antioxidants during conditioning therapy. Hence, we investigated the effect of antioxidant supplementation on peroxidation processes and antioxidant status. We supplemented a patient group (N = 16) [BMT (+)], with oral 45 mg beta-carotene, 825 mg alpha-tocopherol and 450 mg ascorbic acid daily for three weeks before conditioning therapy. Another patient group (N = 10), BMT(-), was not supplemented with antioxidants before conditioning therapy. In order to investigate the physiologic effect of supplement antioxidants a healthy control group (N = 10) was supplemented with the same doses as BMT(+). Peroxide concentrations in plasma were measured by using the cholesterol oxidase (CHOD)-iodide method and antioxidants were measured by HPLC. Before supplementation the beta-carotene and alpha-tocopherol concentrations were comparable in both patient groups. After supplementation significantly higher beta-carotene and alpha-tocopherol concentrations were measured in the supplemented patients, BMT(+), than in the unsupplemented patients, BMT(-). After conditioning therapy, BMT(+) patients showed a significantly higher beta-carotene concentration (p < 0.05) than before supplementation. In BMT(-) patients the beta-carotene (p < 0.05) and alpha-tocopherol concentrations (p < 0.01) decreased significantly and the lipid peroxide concentration increased significantly following conditioning therapy. We conclude that antioxidant supplementation prior to conditioning therapy reduces peroxidation processes induced by conditioning therapy in bone marrow recipients.

Topics: Adolescent; Adult; Antioxidants; Ascorbic Acid; beta Carotene; Bone Marrow Purging; Bone Marrow Transplantation; Dose-Response Relationship, Drug; Drug Therapy, Combination; Feasibility Studies; Female; Humans; Leukemia; Lipid Peroxidation; Male; Middle Aged; Premedication; Reactive Oxygen Species; Vitamin E

P-glycoprotein (P-gp or MDR1) is an ATP-binding cassette (ABC) transporter. It is involved in the efflux of several anticancer drugs, which leads to chemotherapy failure and multidrug resistance (MDR) in cancer cells. Representative secondary metabolites (SM) including phenolics (EGCG and thymol), terpenoids (menthol, aromadendrene, β-sitosterol-O-glucoside, and β-carotene), and alkaloids (glaucine, harmine, and sanguinarine) were evaluated as potential P-gp inhibitors (transporter activity and expression level) in P-gp expressing Caco-2 and CEM/ADR5000 cancer cell lines. Selected SM increased the accumulation of the rhodamine 123 (Rho123) and calcein-AM (CAM) in a dose dependent manner in Caco-2 cells, indicating that they act as competitive inhibitors of P-gp. Non-toxic concentrations of β-carotene (40μM) and sanguinarine (1μM) significantly inhibited Rho123 and CAM efflux in CEM/ADR5000 cells by 222.42% and 259.25% and by 244.02% and 290.16%, respectively relative to verapamil (100%). Combination of the saponin digitonin (5μM), which also inhibits P-gp, with SM significantly enhanced the inhibition of P-gp activity. The results were correlated with the data obtained from a quantitative analysis of MDR1 expression. Both compounds significantly decreased mRNA levels of the MDR1 gene to 48% (p<0.01) and 46% (p<0.01) in Caco-2, and to 61% (p<0.05) and 1% (p<0.001) in CEM/ADR5000 cells, respectively as compared to the untreated control (100%). Combinations of digitonin with SM resulted in a significant down-regulation of MDR1. Our findings provide evidence that the selected SM interfere directly and/or indirectly with P-gp function. Combinations of different P-gp substrates, such as digitonin alone and together with the set of SM, can mediate MDR reversal in cancer cells.

Topics: Alkaloids; Antineoplastic Agents, Phytogenic; ATP Binding Cassette Transporter, Subfamily B, Member 1; Benzophenanthridines; beta Carotene; Caco-2 Cells; Colonic Neoplasms; Digitonin; Dose-Response Relationship, Drug; Drug Combinations; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Drug Synergism; Fluoresceins; Humans; Isoquinolines; Leukemia; Phenols; Phytochemicals; Phytotherapy; Plant Extracts; Rhodamine 123; RNA, Messenger; Terpenes

Overwhelming evidence indicates that consumption of fruits and vegetables with antioxidant properties correlates with reduced risk for cancers, including leukemia. Carrots contain beneficial agents, such as β-carotene and polyacetylenes, which could be effective in the treatment of leukemia. This study investigated the effect of carrot juice extracts on myeloid and lymphoid leukemia cell lines together with normal hematopoietic stem cells. Leukemia cell lines and nontumor control cells were treated with carrot juice extracts for up to 72 hours in vitro. Induction of apoptosis was investigated by using annexin V/propidium iodide staining followed by flow cytometric analysis, and results were confirmed by using 4'-6-diamidino-2-phenylindole morphology. Effects on cellular proliferation were investigated via cell cycle analysis and cell counts. Treatment of leukemia cell lines with carrot juice extract induced apoptosis and inhibited progression through the cell cycle. Lymphoid cell lines were affected to a greater extent than were myeloid cell lines, and normal hematopoietic stem cells were less sensitive than most cell lines. This study has shown that extracts from carrots can induce apoptosis and cause cell cycle arrest in leukemia cell lines. The findings suggest that carrots may be an excellent source of bioactive chemicals for the treatment of leukemia.

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Apoptosis; beta Carotene; Beverages; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Daucus carota; Flow Cytometry; HL-60 Cells; Humans; Leukemia; Plant Extracts; Polyynes; Vegetables

In this communication, we report the efficacy of beta-carotene towards differentiation and apoptosis of leukemia cells. Dose (20 microM) and time dependence (12 h) tests of beta- carotene showed a higher magnitude of decrease (significance p < 0.05) in cell numbers and cell viability in HL-60 cells than U937 cells but not normal cell like Peripheral blood mononuclear cell (PBMC). Microscopical observation of beta-carotene treated cells showed a distinct pattern of morphological abnormalities with inclusion of apoptotic bodies in both leukemia cell lines. When cells were treated with 20 microM of beta-carotene, total genomic DNA showed a fragmentation pattern and this pattern was clear in HL-60 than U937 cells. Both the cell lines, on treatment with beta- carotene, showed a clear shift in G(1) phase of the cell cycle. In addition the study also revealed anti-oxidant properties of beta-carotene since there was reduction in relative fluorescent when treated than the control at lower concentration. Collectively this study shows the dual phenomenon of apoptosis and differentiation of leukemia cells on treatment with beta-carotene.

Topics: Anticarcinogenic Agents; Apoptosis; beta Carotene; Cell Cycle; Cell Differentiation; Cell Proliferation; DNA Fragmentation; Flow Cytometry; G1 Phase; HL-60 Cells; Humans; Leukemia; Neoplasms; Reactive Oxygen Species; U937 Cells

The influence of beta-carotene (BC) and its derivatives on differentiation, proliferation and apoptosis in three human acute leukemia cell lines was studied. We investigated: (i) the cellular uptake of BC, (ii) the cytotoxicity, (iii) the effect on cell cycle progression and/or apoptosis. The dose- and time-dependent pattern of cellular BC uptake in all studied cell lines was seen. We did not observe any cytotoxic effect of BC and ATRA in the chosen concentrations. There was only limited effect of BC on gene expression. The microarrray analysis of U-937 cell line exposed to BC for 72 h showed an increased expression of BAX gene. This finding was confirmed by real-time Q-PCR analysis, and supported by a flow cytometry apoptosis tests. We did not observe any influence of studied components on cellular proliferation. The induction of differentiation after incubation with ATRA in HL-60 cells was noted. The induction of cellular apoptosis by BC was seen in all studied cell lines. We demonstrated that BC used in the concentrations achievable in vivo does not affect the proliferation and differentiation process of the studied leukemic cell lines, but can influence and enhance the apoptosis by modulating the expression of the regulatory genes.

Topics: Apoptosis; beta Carotene; Cell Differentiation; Cell Division; Cell Line, Tumor; Drug Evaluation, Preclinical; Flow Cytometry; Gene Expression Regulation, Neoplastic; HL-60 Cells; Humans; Leukemia; Microarray Analysis; U937 Cells

Serum antioxidant vitamins A (retinol) and E (alpha-tocopherol), beta-carotene, zinc, and selenium, and cholesterol and related proteins for 170 children with newly diagnosed malignancy were measured at diagnosis and 6 months after initiation of treatment, and compared with those of 632 cancer-free controls. Incident cancer cases and controls were 1-16 years old and recruited between 1986 and 1989. At diagnosis, age- and sex-adjusted serum concentrations of retinol, beta-carotene, zinc, and alpha-tocopherol were significantly inversely associated with cancer. No significant decreases in mean values were observed at 6 month, except for the alpha-tocopherol-to-cholesterol ratio in patients with bone tumors and serum zinc in bone tumors and central nervous system malignancies. An increase during the period of treatment was found for retinol and selenium in leukemia patients. beta-carotene was maintained at the initial concentrations determined prior to therapy. These findings provide further information about micronutrient requirements in children with cancer.

Topics: Adolescent; Antioxidants; beta Carotene; Bone Neoplasms; C-Reactive Protein; Case-Control Studies; Central Nervous System Neoplasms; Child; Child, Preschool; Cholesterol; Chromatography, High Pressure Liquid; Female; Follow-Up Studies; Humans; Immunoglobulins; Infant; Leukemia; Male; Micronutrients; Neoplasms; Pilot Projects; Selenium; Serum Albumin; Vitamin A; Vitamin E; Zinc

Blood from 19 patients was examined for the essential antioxidants alpha-tocopherol and beta-carotene before, during, and after bone marrow transplantation (BMT). Marrow ablation and immunosuppression for BMT conditioning was achieved by treatment with high-dose chemotherapy, mostly combined with total body irradiation. All patients required total parenteral nutrition beginning 1 wk before BMT. After conditioning therapy the concentration of absolute and lipid-standardized alpha-tocopherol and beta-carotene in plasma decreased significantly, presumably as a result of an enhanced breakdown of these antioxidants. The loss of these lipid-soluble antioxidants has to be considered as a possible cause for early posttransplant organ toxicity.

Topics: Adolescent; Adult; Anemia, Aplastic; beta Carotene; Bone Marrow Transplantation; Carotenoids; Cholesterol; Combined Modality Therapy; Erythrocyte Membrane; Female; Humans; Leukemia; Male; Myelodysplastic Syndromes; Neuroblastoma; Vitamin E

A total of 13 patients receiving bone marrow transplants (BMT) for treatment of different haematological diseases were investigated. Conditioning therapy preceding BMT consisted of fractionated total-body irradiation (12 Gy) and high-dose chemotherapy with cyclophosphamide (2 +/- 60 mg/kg). Patients stratified to be at high risk for relapse (6/13) were additionally treated with etoposide (30 mg/kg). Plasma concentrations of absolute and lipid-standardized antioxidants (alpha-tocopherol and beta-carotene) decreased following conditioning therapy, presumably as the result of an enhanced breakdown of these antioxidants. Etoposide treatment did not amplify the loss of essential anti-oxidants but significantly increased lipid hydroperoxide concentrations in serum. We suggest that the abnormal generation of lipid hydroperoxides is the result of free radical formation.

Topics: Anemia, Aplastic; Antioxidants; beta Carotene; Bone Marrow Transplantation; Carotenoids; Combined Modality Therapy; Etoposide; Humans; Leukemia; Lipid Peroxidation; Lipid Peroxides; Myelodysplastic Syndromes; Parenteral Nutrition; Radiotherapy Dosage; Time Factors; Vitamin E