cDNA cloning and sequence analysis of the lectin genes of the Korean mistletoe (Viscum album coloratum).
We previously isolated a lectin of the Korean mistletoe (Viscum album coloratum). The cDNA clones that encode the A- or the B-chain of the Korean mistletoe lectin were cloned by reverse transcriptase polymerase chain reaction (RT-PCR). The mRNAs that were extracted from the Korean mistletoe were amplified, ligated into the pGEM-T easy vector, and screened with a Korean mistletoe lectin-specific probe. The probe was prepared by PCR amplification of the Korean mistletoe DNA using a primer set designed on the basis of amino acid sequences of the Korean mistletoe lectin that we had purified and reported. Unlike a recent report, which states that the European mistletoe lectin gene has no isoforms, several different clones of the A- and B-chains of the Korean mistletoe lectin were cloned from the same primer set. Three clones of each were selected for sequencing. The sizes of the A-chains were 762, 762, and 768 bp, respectively. The B-chain sizes were 798, 789, and 789 bp, respectively. Each of the clones showed significant variation in the amino acids sequence, including the N-linked glycosylation sites of the lectin. The sequence analysis of each of the Korean lectin clones, in comparison with the European mistletoe lectin and the other type II ribosome binding proteins, is discussed in the text. In addition, Southern blot analysis of the Korean mistletoe genomic DNA, restricted by different enzymes and hybridized with the lectin DNA, showed multi-bands, supporting the existence of multicopy genes or a gene family. These data suggest that heterogeneity of the mistletoe lectin is not only introduced by post-translational modifications, but also by expression of isotypes of the lectin genes. (+info)
Comparative analysis of phenolic acids in mistletoe plants from various hosts.
Phenolic acids present in mistletoe plants collected from various hosts were analysed with the use of HPLC. The following numbers of compounds were found in the mistletoe plant material gathered from respective hosts: Sorbus aucuparia- 12 compounds; Acer plantanoides--14 compounds: Malus domestica, Pyrus communis and Populus nigra--13 compounds each; Quercus robur--15 compounds. Altogether 21 phenolic acids were chromatographically identified in the tested material. The compounds were either free or combined as esters or glycosides. Comparative chromatography revealed qualitative differences in the investigated compounds between the various plant materials. For example o-coumaric acid was only found in mistletoe hosted by Quercus robur. Digallic acid was only found in the plant material hosted by Acer plantanoides. Qualitative and quantitative composition of mistletoes hosted by Malus domestica and Pyrus communis showed considerable similarities as far as phenolic acids were concerned. Moreover. vanillic acid. absent in all other batches of plant material, seemed to be characteristic of the above mistletoes. Quantitative HPLC analysis demonstrated a considerable content of salicylic acid (39.55 mg%) in mistletoe hosted by Sorbus aucuparia. Apart from the above material, this compound was only present in small quantities in plants hosted by Populus nigra (15.63 mg%) and Quercus robur (2.63 mg%). (+info)
Induction of apoptosis of endothelial cells by Viscum album: a role for anti-tumoral properties of mistletoe lectins.
BACKGROUND: Viscum album (VA) preparations consist of aqueous extracts of different types of lectins of VA. Mistletoe lectins have both cytotoxic and immunomodulatory properties that support their study for the development for cancer therapy. However, the mechanisms of the anti- tumoral properties in vivo of mistletoe lectins are not fully understood. Because endothelial cells (EC) play a pivotal role in tumor angiogenesis, we tested the hypothesis that VA extracts induce endothelial cell death and apoptosis. MATERIALS AND METHODS: We investigated the effect of various VA preparations on both human venous endothelial cell (HUVEC) and immortalized human venous endothelial cell line (IVEC) using morphologic assessment of EC, FACScan analysis after propidium iodine and annexin V labeling, and detection of cleavage of poly(A)DP-ribose polymerase (PARP). RESULTS: All tested VA preparations, except Iscador P, were cytotoxic in IVEC. Apoptosis, assessed by morphologic examination, annexin V labeling, and Western blot analysis for PARP cleavage, was involved in HUVEC cell death induced by VA preparations derived from plants that grow on oak trees (VA Qu FrF). CONCLUSIONS: Results from the present study suggest that VA extract-induced endothelial apoptosis may explain the tumor regression associated with the therapeutic use of VA preparations and support further investigations to develop novel anti-angiogenic compounds based on mistletoe compounds. (+info)
Phase II study of viscum fraxini-2 in patients with advanced hepatocellular carcinoma.
Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Although a wide range of therapeutic options is available, the efficacy of these methods and the prognosis of patients with HCC remain very poor. This study was conducted to evaluate the efficacy and safety of viscum fraxini-2 in patients with chemotherapy-naive, advanced hepatocellular carcinoma. 23 patients with unrespectable HCC who had received no prior systemic chemotherapy with objectively measurable tumors were enrolled on this study. The mistletoe preparation for the study is an aqueous injectable solution. It contains one milliliter of viscum fraxini in dilution stage-2 (15 mg extract of 20 mg mistletoe herb from ash tree, diluted in di-natrium-mono-hydrogen phosphate, ascorbic acid and water) which is equivalent to 10 000 ng/ml injection ampoules. 2 ampoules of viscum fraxini-2 were administered subcutaneously once weekly. As assessed by conventional imaging criteria, 3 (13.1%) patients have achieved complete response, 2 (8.1%) patients have achieved a partial response. 9 (39.1%) had progressive disease while 9 (39.1%) patients didn't have evaluation of response due to early death. The median overall survival time for all patients was 5 months (range 2-38 months), for those who achieved a CR was 29 months (range 12-38 months) and, for those who achieved a PR was 6.5 months (range 6-7 months). The median progression free survival for all patients was 2 months (range 1-38 months), for those who achieved a CR, it was 29 months (range 8-38 months) and for those who achieved a partial response, it was 5 months (range 4-6 months). No hematologic toxicity has been encountered. The spectrum of non-hematologic toxicity was mild. The WHO toxicity criteria grade 3-4 were 34.8% drug related fever, 13.1% erthyma at injection site and 17.4% pain at the site of injection. No drug related discontinuation or toxic deaths have occurred. Viscum fraxini-2 seems to be particularly promising in patients with advanced HCC, it shows antitumor activity and low toxicity profile. Further studies in combination with other active agents are clearly warranted. (+info)
Differences in amino acid sequences of mistletoe lectin I and III B-subunits determining carbohydrate binding specificity.
Toxic lectins of European mistletoe Viscum album L.--MLI (viscumin), MLII and MLIII--are present in water extracts of this plant. Earlier we have cloned the full-length gene of MLIII precursor [A.G. Tonevitsky, I.I. Agapov, I.B. Pevzner, N.V. Maluchenko, M.M. Mojsenovich, U. Pfueller, M.P. Kirpichnikov, (2004) Biochemistry (Mosc.), 69 (6), 790-800, in press]. Here for the first time we report the cloning and expression in Escherichia coli cells of MLIII gene fragment encoding the carbohydrate-binding subunit. We have proved with our panel of monoclonal antibodies against ML toxins that the cloned fragment encoded MLIII B-subunit. The immunochemical and sugar-binding activities of renatured recombinant MLIII B-subunit were demonstrated in ELISA and ELLA, respectively. The comparative analysis of amino acid sequences of the cloned rMLIIIB and the B-subunits of other type II RIPs--MLI, ricin, abrin and nigrin b--was performed, revealing the main differences in primary structure of MLI and MLIII B-chains, which could determine their sugar specificity. The antigenicity analysis of MLI and MLIII B-subunits showed one epitope 25RDDDFRDGNQ34 in MLIB that is absent in MLIIIB sequence. The role of the toxic lectins and their subunits in immunological properties of mistletoe extracts is discussed. (+info)
Influence of complementary Viscum album (Iscador) administration on microcirculation and immune system of ear, nose and throat carcinoma patients treated with radiation and chemotherapy.
With the techniques of vital microscopic and reflection spectrometric imaging, representative characteristics of microcirculation and immunology of white blood cells were evaluated before, during and after radiotherapy and chemotherapy of patients suffering from ear, nose and throat carcinomas. Adverse effects of radiotherapy and chemotherapy on the microcirculation and the immune system were decreased and reconstitution processes were accelerated by complementary administration of a standardized mistletoe extract (Iscador). (+info)
Perioperative application of the Viscum album extract Isorel in digestive tract cancer patients.
BACKGROUND: It is assumed that perioperative immunomodulation of cancer patients can attenuate cellular and humoral deficiencies thus improving their overall health status. Mistletoe (Viscum album L.) anticancer drugs are likely candidates for such adjuvant therapy, because they do not have major adverse side-effects but have dual desirable activities; immune-modulating effects and relatively selective cytotoxicity for cancer cells. MATERIALS AND METHODS: We used the aqueous extract Isorel, which is produced from the entire plant and is validated for batch consistency. The study involved 70 cancer patients, divided into two groups: Isorel-treated group of 40 patients who received Isorel for 2 pre- and 2 post-operative weeks (1 esophageal, 16 gastric, 2 pancreatic and 21 colorectal carcinomas) and the age- and sex-matched control group of 30 patients that did not receive Isorel (2 esophageal, 9 gastric, 3 pancreatic, 1 ileac and 15 colorectal carcinomas). Blood samples were obtained to study parameters of the immune system before the surgery and the drug administration (DO) and on the postoperative days 1 and 14 (D1, D14). The overall health status was evaluated after 60 days by the Kamofsky Performance Index and by the Analogic Scale of Anxiety. The results were compared by Student's t-test and one-way ANOVA test. RESULTS: Isorel significantly attenuated the immuno-suppressive effects of surgery observed for the Isorel-treated group, increasing the number of NK cells, the T and B cells, in particular T-helper cells, complement, IgA, IgG and IgM values also in comparison to the respective D0 values. Both the Kamofsky status and the Anxiety Scale improved remarkably in Isorel-treated patients in comparison to the control. CONCLUSION: The results of this study indicate that perioperative use of the mistletoe drug Isorel can improve immune competence and the overall health status of cancer patients undergoing surgery. (+info)
Reducing malignant ascites accumulation by repeated intraperitoneal administrations of a Viscum album extract.
BACKGROUND: Malignant ascites is a major problem in the management of advanced stages of certain malignancies. The possibility of reducing the accumulation of ascites by intraperitoneal injections of a Viscum album extract (Iscador M) was evaluated. PATIENTS AND METHODS: Twenty-three patients, with end-stage malignancies of varying histology, requiring repeated peritoneal punctures, were eligible for analysis. The time-interval between the first two punctures was measured and defined as the baseline. Following each subsequent puncture, Iscador M 10 mg was injected intraperitoneally. The intervals between later punctures were compared to previous intervals. RESULTS: Following the first injection, the median time-interval between injections increased from 7 to 12 days, reaching 13 days after the second injection. No toxicity was observed. CONCLUSION: This phase II study suggests that installation of Iscador M into the peritoneal cavity may reduce the need for repeated punctures. A randomized trial is needed to confirm these promising preliminary results. (+info)