Effects of Viscum album L. on cyclophosphamide-treated peripheral blood mononuclear cells in vitro: sister chromatid exchanges and activation/proliferation marker expression

Viscum pleurodesis is as effective as talc pleurodesis and tends to have less adverse effect

PURPOSE

Many patients diagnosed with advanced cancer have malignant pleural effusion that does not respond to chemotherapy or radiation therapy. These patients often have respiratory symptoms, especially dyspnea. In order to relieve these symptoms, various procedures including chemical pleurodesis have been performed. Although talc is the most widely used and effective sclerosing agent, there it has various adverse effects. The objective of this study was to determine whether Viscum (ABNOVA Viscum® Fraxini Injection, manufactured by ABNOVA GmbH, Germany) could be used as an agent to replace talc in clinical practice.

METHODS

Data of 56 patients with malignant pleural effusion who received chemical pleurodesis after tube thoracostomy from January 2003 to December 2017 were retrospectively reviewed to analyze clinical course and response after pleurodesis with each agent.

RESULTS

After pleurodesis, changes in numeric rating scale (NRS) was 1.4 ± 1.6 in the talc group and 0.5 ± 1.5 in the Viscum group (p = 0.108). Changes in white blood cell counts after pleurodesis were 4154.8 ± 6710.7 in the talc group and 3487.3 ± 6067.7 in the Viscum group (p = 0.702). Changes in C-reactive protein (CRP) were 9.03 ± 6.86 in the talc group and 6.3 ± 7.5 in the Viscum group (p = 0.366). The success rate of pleurodesis was 93.3% in the talc group and 96% in the Viscum group (p = 0.225).

CONCLUSION

Viscum pleurodesis showed comparable treatment results with talc pleurodesis while its adverse effects such as chest pain and fever tended to be relatively weak.

Interaction of standardized mistletoe (Viscum album) extracts with chemotherapeutic drugs regarding cytostatic and cytotoxic effects in vitro

BACKGROUND

Given the importance of complementary and alternative medicine (CAM) to cancer patients, there is an increasing need to learn more about possible interactions between CAM and anticancer drugs. Mistletoe (Viscum album L.) belongs to the medicinal herbs that are used as supportive care during chemotherapy. In the in vitro study presented here the effect of standardized mistletoe preparations on the cytostatic and cytotoxic activity of several common conventional chemotherapeutic drugs was investigated using different cancer cell lines.

METHODS

Human breast carcinoma cell lines HCC1937 and HCC1143 were treated with doxorubicin hydrochloride, pancreas adenocarcinoma cell line PA-TU-8902 with gemcitabine hydrochloride, prostate carcinoma cell line DU145 with docetaxel and mitoxantrone hydrochloride and lung carcinoma cell line NCI-H460 was treated with docetaxel and cisplatin. Each dose of the respective chemotherapeutic drug was combined with Viscum album extract (VAE) in clinically relevant concentrations and proliferation and apoptosis were measured.

RESULTS

VAE did not inhibit chemotherapy induced cytostasis and cytotoxicity in any of our experimental settings. At higher concentrations VAE showed an additive inhibitory effect.

CONCLUSIONS

Our in vitro results suggest that no risk of safety by herb drug interactions has to be expected from the exposition of cancer cells to chemotherapeutic drugs and VAE simultaneously.

Cytotoxic effect of mistletoe (Viscum album L.) extract on Jurkat cells and its interaction with doxorubicin

Mistletoe preparations are frequently used by cancer patients because of their ability to stimulate the immunity and to improve the quality of life. Moreover mistletoe and its active substances (especially lectins) possess cytotoxic effect on various cancer cell lines. However, only little is known about its interaction with anticancer drugs. Therefore the cytotoxic and apoptosis-inducing effects of aqueous mistletoe extract (VA) and its interaction with doxorubicin (DOXO) were investigated in Jurkat cells. The results show that VA extract as well as DOXO exert cytotoxic effects on Jurkat cells in a dose-dependent manner. Cytotoxicity of DOXO was much stronger (LC(50) = 11.68 ng/mL) than that of VA extract (LC(50) = 35.67 microg/mL). Their combination led to synergism only at those concentrations that were highly cytotoxic alone. Both substances (alone and in combination) induced DNA fragmentation in Jurkat cells. In conclusion, an aqueous extract prepared from mistletoe tops exerted cytotoxic and apoptosis-inducing effects on Jurkat cells alone as well as in combination with DOXO.

Quality of life and neutropenia in patients with early stage breast cancer: a randomized pilot study comparing additional treatment with mistletoe extract to chemotherapy alone

Background:

Chemotherapy for breast cancer often deteriorates quality of life, augments fatigue, and induces neutropenia. Mistletoe preparations are frequently used by cancer patients in Central Europe. Physicians have reported better quality of life in breast cancer patients additionally treated with mistletoe preparations during chemotherapy. Mistletoe preparations also have immunostimulant properties and might therefore have protective effects against chemotherapy-induced neutropenia.

Patients and Methods:

We conducted a prospective randomized open label pilot study with 95 patients randomized into three groups. Two groups received Iscador® M special (IMS) or a different mistletoe preparation, respectively, additionally to chemotherapy with six cycles of cyclophosphamide, adriamycin, and 5-fluoro-uracil (CAF). A control group received CAF with no additional therapy. Here we report the comparison IMS (n = 30) vs. control (n = 31). Quality of life including fatigue was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ-C30). Neutropenia was defined as neutrophil counts <1,000/μl and assessed at baseline and one day before each CAF cycle.

Results:

In the descriptive analysis all 15 scores of the EORTC-QLQ-C30 showed better quality of life in the IMS group compared to the control group. In 12 scores the differences were significant (p < 0.02) and nine scores showed a clinically relevant and significant difference of at least 5 points. Neutropenia occurred in 3/30 IMS patients and in 8/31 control patients (p = 0.182).

Conclusions:

This pilot study showed an improvement of quality of life by treating breast cancer patients with IMS additionally to CAF. CAF-induced neutropenia showed a trend to lower frequency in the IMS group.

Activation of c-Jun N-terminal kinase 1 (JNK1) in mistletoe lectin II-induced apoptosis of human myeloleukemic U937 cells

Extracts of mistletoe (Viscum album var. coloratum) have been used for several decades as an anticancer immunomodulating agent in clinical fields. However, the mechanism by which the plant extracts kill tumor cells has remained elusive. We investigated the direct effects of beta-galactoside- and N-acetyl-d-galactosamine-specific mistletoe lectin II in inducing apoptotic death of U937 cells. Three distinct components of mistletoe, including beta-galactoside- and N-acetyl-D-galactosamine-specific lectin II (60 kDa), polysaccharides, and viscotoxin (5 kDa), induced apoptotic cell death, characterized by DNA ladder pattern fragmentation of U937 cells at 12 hr after treatment. Consistent with apoptosis of the cells, mistletoe extracts markedly increased the phosphotransferase activity of c-Jun N-terminal kinase 1 (JNK1)/stress-activated protein kinase (SAPK) in U937 cells. Among the three components, lectin II was the most potent in inducing apoptosis as well as JNK1 activation of U937 cells in a dose- and time-dependent manner. Catalytic activation of JNK1 induced by mistletoe lectin II was inhibited by the addition of peptide aC-DEVD-CHO, but not by aC-YVAD-CHO. In addition, mistletoe lectin II induced apoptosis in a variety of cell types including Jurkat T cells, RAW 264.7 cells, HL-60 cells, DLD-1 cells, and primary acute myelocytic leukemic cells.

Comparative study of Korean (Viscum album var. coloratum) and European mistletoes (Viscum album)

A lectin (agglutinin, VCA) from Korean mistletoe (Viscum album L. coloratum) was isolated by affinity chromatograpy on a asialofetuin-Sepharose 4B. The molecular weights of A- and B-chains of VCA were differenf from those of VAAS. The VCA recognized the antibody of VAAs in the Western blot analysis and ELLA system. We also investigated the synergistic effects of the components in mistletoe by dividing the extract into different molecular weight fractions.

Induction of apoptosis by the N-acetyl-galactosamine-specific toxic lectin from Viscum album L. is associated with a decrease of nuclear p53 and Bcl-2 proteins and induction of telomeric associations

The ribosome-inhibiting proteins from Viscum album L., i.e. the mistletoe lectins (ML), were recognized to induce apoptosis in various tumour cell lines and human lymphocytes. However, several aspects of ML-induced cell death are unclear. We report that the galNAc-binding ML III incubated with human lymphocytes mediates a very effective death signal resulting in the binding of Annexin-V and expression of mitochondrial membrane proteins Apo2.7, but also in an influx of the DNA intercalating dye propidium iodide. The addition of the ribosome-inhibiting protein Volkensin also induced Apo2.7 molecules, while Momordin, lacking a carbohydrate-binding chain, did not enter the cell membrane and thus did not affect the cells. However, we observed ML III to preferentially affect CD8+ cells with a memory phenotype (CD62L(lo)) as compared to their CD8+ CD62L(hi) counterparts, CD4+ T cells and CD19+ B cells. Furthermore, ML III did not induce sister chromatid exchange-inducing DNA lesions but reduced the intensity of telomeric signals, increased the frequencies of telomeric associations and C-anaphases and reduced nuclear Bcl-2 and p53 proteins. Whatever the exact mechanisms are, our results provide strong evidence that the ML III-mediated cytotoxicity involves distinct killing pathways, i.e. (1) primary cell death via an induction of apoptosis which may not be dependent on protein and/or RNA synthesis and may not involve p53 and Bcl-2 proteins and (2) a loss of telomeres resulting in chromosomal instability in the surviving cells which is incompatible with life. However, we cannot exclude the possibility that this effect is due to a decrease in nuclear p53 proteins.

Study of an Argentine mistletoe, the hemiparasite Ligaria cuneifolia (R. et P.) Tiegh. (Loranthaceae)

Ligaria cuneifolia (R. et P.) Tiegh. is an hemiparasite species used in Argentine folk medicine as a substitute for the European mistletoe (Viscum album L.) based on its putative activity of decreasing high blood pressure. This paper analyzes flavonoid composition, protein constituents and the possible immunomodulatory and antitumoral effects of this species. Micromolecular study disclosed quercetin-free, quercetin-glycosylated and proanthocyanidins corresponding to cyanidin monomers, which implies a particular metabolic pathway. Proteins present in L. cuneifolia extracts analyzed by SDS-PAGE presented multiple bands with molecular weights ranging from 14 to 90 kD. These features contribute to the characterization of the native mistletoe. As V. album is being used in cancer treatment due to its immunomodulatory and antitumoral activity, the action of aqueous L. cuneifolia extracts on murine lymphocytes was investigated. Culture of murine spleen cells alone or stimulated with Concanavalin A or lipopolysaccharide in presence of L. cuneifolia extracts indicated a certain stimulation of splenocytes alone and an inhibition of splenocytes stimulated with Concanvalin A or lipopolysaccharide. An inhibitory effect was also observed on the proliferation of murine leukemia cells. In addition, aqueous extracts increased nitric oxide production by murine macrophages. These results suggest that L. cuneifolia extracts exert an immunomodulatory effect on the mouse immune system.

Isolation and characterization of beta-galactoside specific lectin from Korean mistletoe (Viscum album var. coloratum) with lactose-BSA-sepharose 4B and changes of lectin conformation

Lectins and its A- and B-chains from Korean mistletoe (Viscum album var. coloratum) were isolated by affinity chromatography on the Sepharose 4B modified by lactose-BSA conjugate synthesized by reductive amination of ligand (lactose) to epsilon-amino groups of lysine residues of spacer (BSA) after reduction by NaCNBH3. The lactose-BSA conjugate was coupled to Sepharose 4B activated by cyanogen bromide. The molecular weight determined by SDS-PAGE were a 31 kD of A-chain and a 35 kD of B-chain. Amino acid analysis and N-terminal sequencing were performed. The effects of pH, temperature and guanidine chloride on the conformation of the lectin were investigated by measuring its intrinsic fluorescence and compared with its hemagglutinating activities. Blue shift was detected on the acidic pH and there was a close relationship between activities and conformation of the lectin. Under denaturing conditions, the tryptophan emission profile of lectin showed typical denaturational red shift which also correspond to the conformations and activity of lectin.

Effects of a phytopreparation from Helleborus niger on immunocompetent cells in vitro

Extracts of Helleborus species are used as phytopreparations with immunostimulatory properties in Romanian traditional medicine. In Germany, Helleborus niger is used in homeopathy and as an adjuvant therapy in the treatment of tumor patients in anthroposophical medicine. In vitro application of an aqueous extract from Helleborus niger resulted in a slight induction of sister chromatid exchanges (SCE) in cultured peripheral blood mononuclear cells (PBMC) from healthy individuals, an effect associated with a slight increase of the [3H]thymidine uptake in the DNA of isolated lymphocytes. Since the cytokines interleukin (IL)-2 and tumor necrosis factor (TNF)-alpha were reported to increase the number of SCE, we measured the concentrations of these cytokines in the supernatants of cultured PBMC treated with the plant extract. Here, no significant changes were observed as compared with the controls, but a trend to higher supernatant concentrations of TNF-alpha in six out of ten individuals was noted. Compared with lymphocytes treated with the alkylating substance, cyclophosphamide, the increase of the SCE levels induced by the plant extract is weak. The relevance of this DNA destabilizing property remains to be clarified.

Induction of apoptosis in human lymphocytes treated with Viscum album L. is mediated by the mistletoe lectins

Viscum album L. (VAL) is a phytopreparation used in adjuvant cancer therapy with both immunostimulatory and DNA stabilizing properties at low drug concentrations and cytostatic/cytotoxic properties at higher concentrations. The present work examines the cytotoxic effects of VAL extracts produced from mistletoes grown on different host trees and of purified toxic proteins from VAL, such as the D-galactose-specific lectin I (ML I), the N-acetyl-D-galactosamine-specific ML II and ML III, and crude viscotoxins towards cultured human lymphocytes. The decrease in the number of cultured lymphocytes and blast cells treated with whole plant extracts from VAL was host tree-specific. Nevertheless, there was no close correlation to the content of MLs or viscotoxins. Using the purified proteins, it became obvious that the cell killing was mediated by the induction of apoptosis, as measured by the appearance of a hypodiploid DNA peak using flow cytometry. ML III was the most effective to induce apoptosis, followed by ML II and ML I, while the viscotoxins and oligosaccharides from VAL did not. By measuring the surface expression of IL-2R alpha chains, transferrin receptors and APO-1/Fas molecules on non-apoptotic T cells, no significant changes were observed at low ML concentrations (1 ng/ml), but their decrease at higher ones. Our findings suggest that there might be at least two different ways of cell killing operative in VAL-mediated cytotoxicity: (a) the typical apoptotic cell death with the appearance of hypo-diploid nuclei, and (b) a direct or indirect killing by damaging the cell membrane with subsequent influx of Ca2+ and of the DNA intercalating dye propidium iodide and cell shrinkage. These effects might not be exclusive, as they probably occur simultaneously.