Viscum album (mistletoe) extract for dogs with cancer?

Compared with the options available to human patients with cancer, treatment choices for dogs are often more limited. Chemotherapy is frequently the first-line treatment for many cancers. However, its efficacy can be limited, and its side effects can affect the quality of the remaining life. This paper briefly summarizes the experience with Viscum album L. (mistletoe) extract in human patients as a stipulation to consider treatment with mistletoe extract for canines with cancer. The mistletoe extract contains -among others - lectins and viscotoxins that have documented anti-proliferative effect on cancer cells as well as immune-stimulatory function. Importantly, it also improves the well-being of patients with cancer due to its lectin ML-1 content, which can trigger the release of endorphins. Being cross-reactive with canine cells and having a relatively low side effect profile, it raises the question of whether mistletoe preparations might be considered as part of the treatment approach for dogs with cancer.

Viscum album, as alternative and bridge to palliative chemotherapy in recurrent gallbladder cancer following laparoscopic radical cholecystectomy: a case report

A 78-year-old female patient was initially treated with laparoscopic radical cholecystectomy for gallbladder cancer (pT2aN1M0, stage IIIB). The patient then received adjuvant chemotherapy with gemcitabine. After completion of adjuvant chemotherapy, multiple lymph node metastases were observed in follow-up computed tomography (CT) scan, but the patient refused to go through further chemotherapy. One year after the recurrence, carbohydrate antigen 19-9 (CA19-9) level was 1,925 U/mL with follow-up high-resolution CT/abdomen-pelvic CT showing the increased size of multiple lymph node metastases, and the patient began to undergo Viscum album therapy (0.2 mg, subcutaneously, three times a week). After the V. album therapy was initiated, a decrease in the size of metastatic lymph nodes and CA19-9 level, which was decreased to 252 U/mL, was observed. Seventeen months after continuous V. album therapy, the patient agreed to have palliative chemotherapy. The patient underwent gemcitabine plus cisplatin chemotherapy and showed stable disease during follow-up. This case report suggests that V. album therapy showed anticancer effects and may act as a bridge to palliative chemotherapy for patients with inappropriate general conditions to undergo chemotherapy for recurrent gallbladder cancer.

Mistletoe Extracts during the Oncological Perioperative Period: A Systematic Review and Meta-Analysis of Human Randomized Controlled Trials

BACKGROUND

We aim to evaluate the safety and efficacy of mistletoe extract (ME) use during the oncological perioperative period.

METHODS

Details registered a priori on PROSPERO (CRD42018086168).

RESULTS

Seven RCTs (comprising 663 participants in nine reports) and three nonrandomized studies were included. In five RCTs, ME was evaluated as adjunctive care and the control group had no additional intervention, whereas in two RCTs, ME was compared head-to-head against common cancer treatments (i.e., etoposide or bacillus Calmette-Guérin) with the intervention groups not receiving standard care. Meta-analyses found no evidence for a difference between ME and no added therapy for mortality and recurrence (RR, 95% CI: 1.00, 0.79-1.27; and 1.03, 0.79-1.33, respectively). Two RCTs reported beneficial effects of ME on immune cells, specifically natural killer cells, in colorectal cancer, and one RCT reported quality of life improvement. Two RCTs reported ME discontinuations due to adverse events and grade 3/4 toxicities. Nevertheless, no safety signals were detected from these 10 studies. Quality appraisal revealed a substantial risk of bias.

CONCLUSIONS

Preliminary data are encouraging for mistletoe extracts, particularly in the context of colorectal cancer. However, the evidence is limited by the number of studies, an evaluation of different outcomes, and methodological limitations. Further high-quality research is warranted.

Viscum album Induces Apoptosis by Regulating STAT3 Signaling Pathway in Breast Cancer Cells

In this study, we investigated the potential anticancer effects of Viscum album, a parasitic plant that grows on Malus domestica (VaM) on breast cancer cells, and explored the underlying mechanisms. VaM significantly inhibited cell viability and proliferation and induced apoptosis in a dose-dependent manner. VaM also regulated cell cycle progression and effectively inhibited activation of the STAT3 signaling pathway through SHP-1. Combining VaM with low-dose doxorubicin produced a synergistic effect, highlighting its potential as a promising therapeutic. In vivo, VaM administration inhibited tumor growth and modulated key molecular markers associated with breast cancer progression. Overall, our findings provide strong evidence for the therapeutic potential of VaM in breast cancer treatment and support further studies exploring clinical applications.

Green Synthesis of Zinc Oxide Nanoparticles Using Viscum album Extracts: Unveiling Bioactive Compounds, Antibacterial Potential, and Antioxidant Activities

The current study explored the antioxidant and antibacterial capabilities of zinc oxide nanoparticles (ZnONPs) synthetized using methanolic leaf extracts of the medicinal herb Viscum album. Through TEM investigation and UV-Vis analysis, which peaked at 406 nm, the synthesis of ZnONPs was verified. TEM analyses showed that the synthesized ZnONPs had a size distribution with an average of 13.5 nm and a quasi-spherical shape. Forty-four phytoconstituents were found in the methanolic leaf extracts of V. album. Additionally, a comparison of the antibacterial effectiveness and antioxidant capacity of aqueous and methanolic extracts of wild-grown V. album phytomedicine and green-manufactured ZnONPs was conducted. The green-generated ZnONPs were examined against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa and shown to have superior antibacterial activity by 22%, 66%, and 44%, respectively, as compared to wild herbal medicinal extracts. Since the ZnONPs' aqueous extracts had higher concentrations of DNA gyrase-B inhibitory components, they were shown to be more effective in limiting bacterial growth. In contrast to the percentages of 49% and 57% for a wild plant extract, the aqueous- and methanolic-extract-mediated green ZnONPs, with a 100 g/mL concentration, showed 94% and 98% scavenging capacity for DPPH free radicals, respectively. However, methanolic extracts were more effective than aqueous extracts in terms of the antioxidant analyses. This study establishes that greenly produced ZnONPs have the potential to be used in nanomedicine to treat bacteria that are resistant to a variety of drugs, as well as those with reactive oxygen species toxicity.

Patient' and social aspects related to complementary mistletoe therapy in patients with breast cancer: A systematic review commissioned by the German agency for Health Technology Assessment

PURPOSE

To mitigate side effects of conventional cancer care and improve quality of life, many patients with breast cancer in German-speaking countries opt for mistletoe therapy in addition to standard treatment. To understand the value for users, we evaluated the domain "Patient and Social aspects" in a health technology assessment on complementary mistletoe therapy in patients with breast cancer.

METHODS

A systematic review was conducted according to PRISMA guidelines. Fifteen electronic databases and the internet were searched. Qualitative studies were analyzed using qualitative content analysis; quantitative studies were systematically summarized in evidence tables.

RESULTS

Seventeen studies out of 1203 screened publications with 4765 patients and 869 healthcare professionals were included in the review. The median proportion of patients using mistletoe therapy was 26.7% (range: 7.3-46.3%). Predictors for use were younger age and higher educational level. Main reasons for patients' use of mistletoe therapy were to leave nothing untried and to be actively involved in the treatment process. Reasons against use were related to a lack of knowledge or uncertainty regarding effectiveness and safety. Physicians mainly aimed to support the patient's physical condition as main reason for use and a lack of resources and knowledge as main reason against use.

CONCLUSION

Mistletoe therapy was commonly used in the treatment of breast cancer despite a lack of scientific knowledge among patients and physicians. Transparent communication on motivation for use and its potential effect enables realistic expectations. Relatively small samples of mistletoe therapy users limit the representativeness and validity of our results.

The Anti-Inflammatory Activity of Viscum album

The therapeutic story of European mistletoe (Viscum album L.) presents a seesawing profile. In ancient times, this hemiparasitic plant was considered a panacea and even to be endowed with exceptional beneficial properties. In more recent times, despite its multiple uses in traditional medicines, some parts of the plant, in particular the berries, were considered poisonous and dangerous, including concerns of cytotoxicity, which spread serious suspicion on its medicinal utility. However, since the last century, medical interest in mistletoe has come back in force due to its utilization in clinical cancer treatments, based on its selective action on tumor cells. In Central Europe, the hydro-alcoholic extracts of European mistletoe register a relevant and continuous utilization in anthroposophic medicine, which is a holistic system that includes the utilization of phytomedicinal substances. In Switzerland and Germany, most physicians and patients use these products as complementary therapy in oncological treatments. However, despite its increasing use in this field, the results of mistletoe's use are not always convincing, and other aspects have appeared. Nowadays, products that contain mistletoe are utilized in several fields, including diet, phytotherapy, veterinary medicine and homeopathy, but in particular in cancer therapies as coadjuvant factors, in consideration of several positive effects including effects in the improvement of quality-of-life conditions and reinforcement of the immune system. In this review, based on the understanding of the association between cancer and inflammation, we propose a relationship between these recent uses of mistletoe, based on its antioxidant properties, which are supported by phytochemical and pharmacological data. The unicity of mistletoe metabolism, which is a direct consequence of its hemiparasitism, is utilized as a key interpretation element to explain its biological properties and steer its consequent therapeutic uses.

Characterization of Viscum album L. Effect on Immune Escape Proteins PD-L1, PD-L2, and MHC-I in the Prostate, Colon, Lung, and Breast Cancer Cells

BACKGROUND

Viscum album L. (VA) preparations possess immunomodulatory properties and are used in complementary medicine to support cancer therapy. It is unclear if there is an impact of VA on the expression of immune checkpoint proteins on the surface of cancer cells. This study was designed to investigate the role of commercially available VA preparations on checkpoint programmed death ligand 1, 2 (PD-L1, PD-L2) and on major histocompatibility complex class I (MHC-I).

METHODS

Four human cancer cell lines (prostate, colon, lung, and breast) were assayed for their PD-L1, PD-L2, and MHC-I level after stimulation with interferon-gamma (IFN-γ). The toxicity of mistletoe preparations for the cells was analysed. Afterwards, the effect of mistletoe preparations on the PD ligands and MHC-I was investigated.

RESULTS

Surface protein analysis demonstrated that all tested tumour cell lines increased the PD-L1, PD-L2, and MHC-I-expression, but to different extents, after IFN-γ stimulation. Treatment with VA extracts did not influence the viability of the cells. The expression of PD ligands and MHC-I was not affected by incubation with the VA preparations.

CONCLUSION

Our investigation concludes that VA treatment does not interfere with the expression of PD ligands or MHC-I among selected cancer cells.

Hintergrund

Viscum album L. (VA)-Präparate besitzen immunmodulatorische Eigenschaften und werden in der Komplementärmedizin zur Unterstützung in der Krebstherapie eingesetzt. Es ist jedoch unklar, ob VA einen Einfluss auf die Expression von Immuncheckpoint-Proteinen auf Krebszellen hat. In der vorliegenden Arbeit wurde ein Einfluss von handelsüblichen VA-Präparaten auf die Checkpoint-Proteine programmed death ligand 1, 2 (PD-L1, PD-L2) und major histocompatibility complex class I (MHC-I) untersucht.

Methoden

Vier humane Krebszelllinien der Prostata, des Dickdarms, der Lunge und Brust wurden nach Stimulation mit Interferon-gamma (IFN-γ) auf ihre PD-L1, PD-L2 und MHC-I Konzentration untersucht. Zunächst wurde die Toxizität von Mistelpräparaten auf die Tumorzellen analysiert. Anschließend erfolgte eine Charakterisierung der Wirkung von Mistelpräparaten auf die PD-Liganden und MHC-I.

Ergebnisse

Die Oberflächenproteinanalysen zeigten, dass alle getesteten Tumorzelllinien nach einer IFN-γ-Stimulation die PD-L1, PD-L2 und MHC-I Expression in unterschiedlichem Ausmaß erhöhten. Die Behandlung mit verschiedenen VA-Extrakten hatte keinen Einfluss auf die Viabilität der Zellen, sowie auf die Expression der PD-Liganden und MHC-I.

Schlussfolgerung

Unsere Untersuchung kommt zu dem Schluss, dass eine VA-Behandlung die Expression von PD-Liganden oder MHC-I in den untersuchten Krebszellen nicht beeinflusst.

Alternative management of intractable chylous ascites following robot-assisted pancreaticoduodenectomy of Viscum album sclerotherapy: a case report

A patient showed signs of fever and Hemovac insertion site discharge 8 days after surgery and was admitted. Abdominal paracentesis found milky ascites with triglyceride levels of the peritoneal fluid as high as 1,603 g/mL. Diagnosed as chylous ascites, symptomatic therapy such as empirical antibodies and diuretics was administered with paracentesis before being discharged. The ascites volume increased again, and the patient was re-admitted. The patient was treated with orlistat, octreotide, total parenteral nutrition administration, ascites drainage, and diuretics. Ascites levels increased further and intraperitoneal Viscum was administered. Clear ascites was observed, and the patient was discharged. We reported a case where conventional treatment for chylous ascites that occurred after pancreaticoduodenectomy was shown to be ineffective while Viscum extracted from mistletoe was able to manage chylous ascites.

Viscum album mother tinctures: Harvest conditions and host trees influence the plant metabolome and the glycolytic pathway of breast cancer cells

Viscum album is a semi-parasitic plant used for over one hundred years in complementary cancer therapy. The main commercial drugs used in cancer patients' treatment are derived from the aqueous V. album extracts, whose cytotoxic potential is mostly attributed to the aqueous soluble antitumoral metabolites. On the counterpart, ethanol solvents must be used to obtain V. album mother tinctures. This methodology permits better solubilization of phenolic compounds, among others, which present antitumoral bioactivity. Recently, the metabolomics approach revealed the influence of the host tree on the V. album subspecies differentiation. To increase the scientific information about the chemical differences related to the host trees and to clarify the seasonal influences, in this study, the metabolome of 50 V. album mother tinctures from three subspecies (abietis, album, austriacum) and five host trees (Malus domestica, Quercus sp., Ulmus carpinifolia, Pinus sylvestris, Abies alba) was evaluated using summer and winter plant harvests. The in vitro cytotoxic activities were investigated in breast cancer cells (MDA-MB-231) and immortalized normal human keratinocytes (HaCaT). The summer V. album mother tinctures presented higher cytotoxic activity than winter ones. Among the summer samples, those prepared with V. album subsp. album were more cytotoxic than V. album subsp. abietis and subsp. V. album subsp. austriacum. The V. album harvested from Quercus petraea and Abies alba inhibited the key-glycolytic enzymes: hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK). This activity was related to a reduction in glucose uptake and lactate production, which were host-tree-time-dose-dependent. The untargeted metabolomic approach was able to discriminate the mother tinctures according to respective botanical classes and harvest season. A total of 188 metabolites were annotated under positive and negative modes. Fourteen compounds were responsible for the samples differentiation, and, to the best of our knowledge, eight were described in the Viscum album species for the first time. Our study shows the interruption of the Warburg effect as a novel antitumoral mechanism triggered by V. album mother tinctures, which is related to their metabolite profile. These results bring scientific evidence that encourages the use of V. album mother tinctures as a natural product for cancer therapy.

Articulatin B chain induced dendritic cells maturation and driven type I T helper cells and cytotoxic T cells activation

AIMS

Articulatin (AT), purified from the Chinese mistletoe (Viscum articulatum), belongs to the family of type II ribosome-inactivating proteins (RIPs) that contain two subunits, the A and B chains. The B chain of AT is believed to function by means of interacting with the galactose moiety of glycoproteins or glycolipids on the cell membrane and is internalized into cells through endocytosis. In the study, we aim to investigate the immunomodulatory effects of recombinant articulatin B chain (rATB) on mouse bone marrow-derived dendritic cells (BM-DCs).

MAIN METHODS

Detection of surface markers expression on BM-DCs by flow cytometry. Analysis of RNA and protein expression by RNAseq and Western blotting assays. Assessment of the adaptive immune responses using an in vivo mouse model.

KEY FINDING

Our study presents novel results showing the activation of mouse BM-DCs by rATB, which leads to the induction of CD80, CD86, and MHC II expression as well as primed type I CD4+ T cell differentiation and CD8+ T cell activation. RNAseq and Western blotting assays revealed rATB-induced BM-DC activation to be dependent on the MAPK and NF-κB signaling pathways. In a mouse model, rATB was observed to have adjuvant effects that induced an antigen-specific Th1 immune response.

SIGNIFICANCE

Based on in vitro and in vivo assays, this study shows rATB acting as a potential adjuvant that induces BM-DC activation and antigen-specific Th1 related immune response. rATB might have potential applicability in the development of vaccines against pathogens and tumors.

Cancer-related fatigue in patients treated with mistletoe extracts: a systematic review and meta-analysis

PURPOSE

Cancer-related fatigue remains one of the most prevalent and distressing symptoms experienced by cancer patients. Effective treatments for cancer-related fatigue are needed. The objective of this meta-analysis is to determine the impact of mistletoe extracts as a pharmacological treatment for the management of cancer-related fatigue.

METHODS

We included randomized clinical trials (RCTs) and non-randomized studies of interventions (NRSIs) in cancer patients. Inclusion criteria were cancer-related fatigue severity or prevalence as an outcome and testing of mistletoe extracts compared to control groups. We searched Medline (EuropePMC), Embase, the Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and opengrey.org through October 2020. We assessed the risk of bias using the Cochrane risk of bias tools for RCTs and NRSIs and conducted a meta-analysis.

RESULTS

We performed one meta-analysis with 12 RCTs, including 1494 participants, and one meta-analysis with seven retrospective NRSIs, including 2668 participants. Heterogeneity between the studies was high in both meta-analyses. Most studies had a high risk of bias. A random-effects model showed for RCTs a standardized mean difference of -0.48 (95% confidence interval -0.82 to -0.14; p = 0.006) and for NRSIs an odds ratio of 0.36 (95% confidence interval 0.20 to 0.66; p = 0.0008).

CONCLUSION

Treatment with mistletoe extracts shows a moderate effect on cancer-related fatigue of similar size to physical activity. These results need to be confirmed by more placebo-controlled trials. Future trials should investigate different treatment durations and their effect on cancer-related fatigue in post-treatment cancer survivors.

TRIAL REGISTRATION

This meta-analysis has been registered under the PROSPERO registration number CRD42020191967 on October 7, 2020.

Complete, Durable Remission of Advanced Hepatocellular Carcinoma under Treatment with Viscum album Extracts: A Case Report

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths. Early-stage disease is treated with curative intent, but most patients present with advanced HCC, which carries a poor prognosis. Viscum album extracts (VAE) are used by cancer patients as an adjunct treatment or palliation.

CASE PRESENTATION

A 51-year-old female presented with relapsing multifocal HCC. She declined palliative treatment and commenced intravenous VAE treatment in conjunction with intravenous hepato-protective L-ornithine-L-aspartate (LOLA). She experienced a significant improvement of life-quality and performance status. After 3 months, a significant regression was noted on computerized tomography, and α-fetoprotein was in normal range. Imaging 11 months later confirmed a complete regression. The VAE and LOLA treatment continues to date. The patient had no other cancer-directed therapy. The regression is sustained for more than 5 years at publication, confirmed by regular imaging and serology. The patient is experiencing an unrestricted quality of life.

CONCLUSION

Complete regression of advanced HCC is rare. Responses of HCC to VAE treatment have been reported before. However, this is the first documented case with a complete and durable regression of an HCC under treatment with VAE. Further studies should evaluate VAE treatment in HCC, especially when administered in forms as reported here.

European Mistletoe (Viscum album) Extract Is Cytotoxic to Canine High-Grade Astrocytoma Cells In Vitro and Has Additive Effects with Mebendazole

Malignant gliomas are associated with extremely poor clinical outcomes in both humans and dogs, and novel therapies are needed. Glioma-bearing canine patients may serve as promising preclinical models for human therapies, including complementary medicine. The objective of this study was to evaluate the effects of mistletoe extract (Viscum album) alone and in combination with mebendazole in an in vitro model of canine high-grade astrocytoma using the cell line SDT-3G. SDT-3G cells were exposed to a range of concentrations of mistletoe extract alone to obtain an IC50. In separate experiments, cells were exposed to mebendazole at a previously determined IC50 (0.03 µM) alone or in conjunction with varying concentrations of mistletoe extract to determine the additive effects. The IC50 for mistletoe alone was 5.644 ± 0.09 SD μg/mL. The addition of mistletoe at 5 μg/mL to mebendazole at 0.03 µM led to increased cell death compared to what would be expected for each drug separately. The cytotoxicity of mistletoe in vitro and its additive effect with mebendazole support future expanded in vitro and in vivo studies in dogs and supply early evidence that this may be a useful adjunct therapeutic agent for use in glioma-bearing dogs. To the authors’ knowledge, this is the first published report of Viscum album extract in canine glioma.

Selective Immune Modulating Activities of Viscum album and Its Components; A Possibility of Therapeutics on Skin Rash Induced by EGFR Inhibitors

Viscum album var. coloratum (Kom.) Ohwi is a traditional herbal medicine used in East Asia to treat hypertension, skeletal muscle disorders, and cancer. The inhibitory effects of Viscum album (VA) extract on chemokines and its therapeutic potential in erlotinib-induced skin rash were investigated in this study. ELISA was used to measure the levels of chemokines, MCP-1 and RANTES, which are thought to be mediators of erlotinib-induced skin rash in RAW264.7 cells. Western blot analysis was used to look into the activation of signaling pathways like AKT, MAPK, and EGF. In order to investigate the active compounds in VA extract, solvent fractionation and preparative HPLC were performed sequentially. VA extract significantly reduced the production of TNF-α, MCP-1, and RANTES but not IL-1. Furthermore, macrophage transmigration was inhibited without causing cell toxicity. VA extract had no effect on the phosphorylation of EGF receptors stimulated by EGF or suppressed by erlotinib in both A549, a non-small cell lung cancer cells, and Hacat, a human skin keratinocyte. The isolated viscumneoside III and viscumneoside V from VA extract significantly suppressed the expression of MCP-1, according to activity guided fractionation with organic solvent fractionation and preparative HPLC. These findings suggest that VA extract and its active compounds, viscumneoside III and viscumneoside V, regulate MCP-1 production and may have the potential to suppress erlotinib-induced skin toxicity by modulating macrophage activity without neutralizing anti-cancer efficacy.

Chemical Pleurodesis Using a Viscum album Extract in an Infant with Postoperative Chylothorax: A Case Report

Chylothorax after thoracic surgery is a rare complication, and treatment for refractory chylothorax is challenging. We report a case of chylothorax after cardiothoracic surgery in an infant after failure of conservative management and thoracic duct ligation. The patient underwent chemical pleurodesis with a Viscum album extract. The treatment was successful and chylothorax did not recur.

Thermoresponsive Hydrogel Containing Viscum album Extract for Topic and Transdermal Use: Development, Stability and Cytotoxicity Activity

Viscum album L. (Santalaceae), also known as European mistletoe, is a semi-parasitic plant that grows on different host trees. Our group recently demonstrated the antitumoral activity of ethanolic V. album extracts in vitro, depending on the dose and the host tree, V. album ssp abietis from Abies alba being the most active extract. The goal of this work focused on the development of a new topical formulation containing V. album extracts, evaluation of in vitro toxicity and ex vivo skin permeation assays. The Poloxamer 407 hydrogel containing 5% of dry (VA_DEH) or aqueous (VA_AEH) extract presented dermal compatible pH and microbiological stability for 180 days. The hydrogels flow curve presented a non-linear relation, characteristic of non-Newtonian fluids, and the mean viscosity for the VA_DEH and VA_AEH was 372.5 ± 7.78 and 331.0 ± 2.83 Pa.s, respectively, being statistically different (Welch’s t test; p < 0.01). Additionally, WST-1 in vitro assays revealed a dose-dependent toxicity for both formulations and VA_DEH presented a higher activity than the VA_AEH. The promising cytotoxic potential of VA_DEH lead to the ex vivo skin permeation assay with 2.73 ± 0.19 µg/cm² of chlorogenic acid, which permeated at 8 h, showing a transdermal potential. These in vitro results support the idea that VA_DEH is a novel promising candidate for mistletoe therapy. Therefore, further in vivo and pre-clinical experiments should be performed to evaluate the safety and efficacy of this new dermic delivery system.

Genes from oxidative phosphorylation complexes II-V and two dual-function subunits of complex I are transcribed in Viscum album despite absence of the entire mitochondrial holo-complex I

Mistletoes (Viscum) and close relatives are unique among flowering plants in having a drastically altered electron transport chain. Lack of complex I genes has previously been reported for the mitochondrial genome, and here we report an almost complete absence of nuclear-encoded complex I genes in the transcriptome of Viscum album. Compared to Arabidopsis with approximately 40 nuclear complex I genes, we recover only transcripts of two dual-function genes: gamma carbonic anhydrase and L-galactono-1,4-lactone dehydrogenase. The complement of genes belonging to complexes II-V of the oxidative phosphorylation pathway appears to be in accordance with other vascular plants. Additionally, transcripts encoding alternative NAD(P)H dehydrogenases and alternative oxidase were found. Despite sequence divergence, structural modeling suggests that the encoded proteins are structurally conserved. Complex I loss is a special feature in Viscum species and relatives, as all other parasitic flowering plants investigated to date seem to have a complete OXPHOS system. Hence, Viscum offers a unique system for specifically investigating molecular consequences of complex I absence, such as the role of complex I subunits involved in secondary functions.

Complexome Profiling of Plant Mitochondrial Fractions

Most molecular functions depend on defined associations of proteins. Protein-protein interactions may be transient or long-lasting; they may lead to labile assemblies or more stable particles termed protein complexes. Studying protein-protein interactions is of prime importance for understanding molecular functions in cells. The complexome profiling approach allows to systematically analyze protein assemblies of cells or subcellular compartments. It combines separation of intact protein fractions by blue native (BN) polyacrylamide gel electrophoresis (PAGE) and protein identification as well as quantification by mass spectrometry. Complexome profiling has been successfully applied to characterize mitochondrial fractions of plants. In a typical experiment, more than 1000 mitochondrial proteins are identified and assigned to defined protein assemblies. It allows discovering so far unknown protein complexes, studying assembly pathways of protein complexes and even characterizing labile super- and megacomplexes in the >10 mega-Dalton range. We here present a complexome profiling protocol for the straightforward definition of the protein complex inventory of mitochondria or other subcellular compartments from plants.

Exploring the resources of the genus Viscum for potential therapeutic applications

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Viscum comprises approximately 100 species that are mainly distributed across Africa, Asia and Europe. The extracts and preparations of Viscum species are widely used as common complementary and alternative medicines in the treatment of rheumatism and cancer.

AIM OF THE REVIEW

This review aims to explore the medicinal properties of twelve species belonging to the genus Viscum for potential therapeutic applications.

MATERIALS AND METHODS

We collected online information (including PubMed, CNKI, Google Scholar, and Web of Science) from January 1915 to April 2021 and knowledge from classical books on Chinese herbal medicines available for 12 species of the genus Viscum, including Viscum coloratum (Kom.) Nakai, Viscum album L., Viscum articulatum Burm. f., Viscum liquidambaricola Hayata, Viscum ovalifolium DC., Viscum capitellatum Sm., Viscum cruciatum Sieber ex Boiss., Viscum nudum Danser, Viscum angulatum B.Heyne ex DC., Viscum tuberculatum A.Rich., Viscum multinerve Hayata, and Viscum diospyrosicola Hayata.

RESULTS

At least 250 different compounds have been reported across twelve Viscum species, including amino acid and peptides, alkaloids, phenolic acids, flavonoids, terpenoids, carbohydrates, fatty acids, lipids, and other types of compounds. In particular, for Viscum coloratum (Kom.) Nakai and Viscum album L., the plants, preparations, and bioactive components have been thoroughly reviewed. This has allowed to elucidate the role of active components, including lectins, viscotoxins, flavonoids, terpenoids, phenolic acids, and polysaccharides, in multiple bioactivities, such as anti-cancer, anti-rheumatism arthralgia, anti-inflammation, anti-cardiovascular diseases, enhancing immunity, and anti-chemotherapy side effects. We also evaluated quality control methods based on active compounds, in vivo exposure compounds, and discriminated chemical markers.

CONCLUSIONS

This is the first report to systematically review the pharmaceutical development history, chemical composition, clinical evidence, pharmacological activity, discriminated chemical markers, in vivo exposure, and quality control on twelve distinct species of Viscum plants with medicinal properties. The significant safety and efficacy, along with the minor side effects are constantly confirmed in clinics. The genus Viscum is thus an important medicinal resource that is worth exploring and developing in future pharmacological and chemical studies.

Metabolomics by UHPLC-Q-TOF Reveals Host Tree-Dependent Phytochemical Variation in Viscum album L

Viscum album L., commonly known as European mistletoe, is a hemi-parasitic plant of the Santalaceae family. The in vitro and in vivo effects of V. album differ, according to its host tree. However, little is known about the host-dependent phytochemical diversity in V. album. In this study, the metabolic profiles of V. album ssp. album from Malus domestica Bork., Quercus robur L., and Ulmus carpinifolia Gled were compared. Leaves, stems, and berries were collected in Switzerland, by the same procedure, in September 2016 and 2017. The methanolic extracts were analyzed by ultra-performance liquid chromatography, coupled to electrospray quadrupole time-of-flight mass spectrometry in positive ionization mode. The data were submitted to partial-least square discriminant analysis (PLS-DA) and the results showed that the V. album ssp. album samples were clustered into three groups, according to the three distinct host trees. Seven compounds, with high VIP scores (variable importance in projection), were responsible for this differentiation. The following four compounds were detected in both the harvest years: arginine, pipecolic acid or lysine, dimethoxycoumarin, and sinapyl alcohol, suggesting their use as host specific V. album biomarkers. The present work highlights the importance of standardized harvest and analytical procedures for the reproducibility of the chemical results of herbal materials.

Impact of Oncological Therapy and Viscum album L Treatment on Cancer-Related Fatigue and Internal Coherence in Nonmetastasized Breast Cancer Patients

Introduction:Viscum album L extracts (VA) are frequently used in integrative oncology. Aim of this study was to evaluate the impact of add-on VA applications on various patient-reported outcome measures. Methods: A longitudinal real-world study was conducted, using data from the Network Oncology clinical registry. Primary, nonmetastasized breast cancer patients treated with oncological standard therapy partly combined with VA applications were included. Internal Coherence Cancer-related Fatigue, and EORTC QLQ-C30 questionnaires were assessed at baseline and 6, 12, and 24 months later. Results: A total of 319 patients received standard oncological therapy and 40% of them additionally VA applications. After 6 and 12 months for patients treated with chemotherapy (Ctx) only a significant decline of the thermo-coherence, and worsening of fatigue was observed. For patients receiving VA applications but no Ctx, significant beneficial effects on thermo-coherence, fatigue, and seven EORTC QLQ-C30 scales were observed 24 months later. Adjusted multivariable long-term subgroup (n = 106) regression analysis revealed that Ctx, immuno-, and endocrine therapies had a worsening of 17, 17, and 6 point changes, respectively, for EORTC QLQ-C30 fatigue (P = .0004), while VA applications showed an improvement of 12 point change. A similar impact of improvement (add-on VA) and worsening (standard oncological treatment regimens) on EORTC QLQ-C30 insomnia (P = .009) and physical functioning (P = .005) were observed. Conclusions: In the present real-world study, add-on VA applications had a supportive effect on cancer-related fatigue, insomnia, physical functioning, and thermo-coherence. Thus, VA applications might be suited to alleviate symptom burden during anticancer therapy in breast cancer patients.

Impact of Harvest Conditions and Host Tree Species on Chemical Composition and Antioxidant Activity of Extracts from Viscum album L

The content of plant secondary metabolites is not stable, and factors such as the region/location effect and seasonal variations have an impact on their chemical composition, especially in parasitic plants. Research in this area is an important step in the development of quality parameter standards of medicinal plants and their finished products. The effects of the time and place of harvest and the host tree species on the chemical composition and antioxidant activity of mistletoe extracts were investigated. Statistical tools were used to evaluate the results of the spectrophotometric and LC-ESI-MS/MS studies of the phenolic composition and antioxidant activity. The investigations indicate that the qualitative and quantitative composition, influencing the biological activity of mistletoe extracts, largely depends on the origin of the plant. The mistletoe extracts exhibited a rich phenol profile and high antioxidant activity. The chemometric analysis indicated that mistletoe collected from conifers (Viscum abietis and Viscum austriacum) had the most advantageous chemical composition and antioxidant activity. Moreover, the chemical profile and biological activity of the plant material were closely related to the climatic conditions and location of the harvested plant. Higher levels of phenolic compounds and high antioxidant activity were found in extracts obtained from plant material collected in cold weather with the presence of snow and less sunshine (autumn-winter period).

Effect of mistletoe extract on tumor response in neoadjuvant chemoradiotherapy for rectal cancer: a cohort study

Background

Mistletoe extract, used as a complementary chemotherapeutic agent for cancer patients, has anticancer effects against various malignancies. The aim of the present study was to evaluate the effect of mistletoe extract (Abnoba Viscum Q®) on tumor responses to neoadjuvant chemoradiotherapy (NCRT) for locally advanced rectal cancer.

Methods

This study included patients with rectal cancer who underwent NCRT between January 2018 and July 2020. In the mistletoe group (MG), the patients were administered Abnoba Viscum Q® subcutaneously during chemoradiotherapy—maintained just before surgery. Patient demographics, clinical outcomes, histopathological outcomes, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assay results were compared between the MG and non-mistletoe group (NMG). Two rectal cancer cell lines (SNU-503 and SNU-503R80Gy) were treated with Abnoba Viscum Q® to assess its mechanistic effects in vivo.

Results

Overall, the study included 52 patients (MG: n = 15; NMG: n = 37). Baseline demographics between the two groups were similar, except carbohydrate antigen 19-9 levels and tumor location from the anal verge. There was no difference in the clinical stage between the two groups. A better tumor response in the MG, relative to the NMG, was observed with respect to tumor regression grade (TRG), T stage, and overall tumor–node–metastasis stage. Tumor response was significantly better in the MG than in the NMG in terms of pathologic complete response rate (53.3% vs. 21.6%, P = 0.044), good TRG response (66.7% vs. 32.4%, P = 0.024), T downstaging (86.7% vs. 43.2%, P = 0.004), and overall downstaging (86.7% vs. 56.8%, P = 0.040). The toxicities during NCRT were minimal in both groups. More apoptotic cells were noted in MG samples than in the NMG samples on TUNEL staining. Cleaved caspase-3 level following treatment with Abnoba Viscum Q® was higher in SNU-503R80Gy cells than in SNU-503 cells.

Conclusion

Patients treated with chemoradiation combined with mistletoe extract showed better outcomes than patients not treated with mistletoe extract in terms of tumor responses. This diversity in treatment may improve the efficacy of NCRT, leading to better oncologic outcomes. Prospective and randomized studies with long-term follow-up are warranted to confirm and extend these results.

In vivo effects of Viscum album and probiotics against carbon tetrachloride-induced liver injury

This study tested the possible protective and therapeutic effects of Viscum album extract and probiotics against carbon tetrachloride (CCl₄)-induced acute/chronic liver injury. Male Wistar rats were assigned to seven groups: Control, acute CCl₄, acute V. album + CCl₄, acute V. album + Probiotics + CCl₄, chronic CCl₄, chronic CCl₄ + V. album, and chronic CCl₄ + V. album + Probiotics. Acute and chronic liver injuries were induced by 2 mg/kg CCl₄ (i.p.) and 1 mg/kg CCl₄ (i.p.), respectively. The extract and probiotics were administered daily to related groups. Serum enzyme activities, lipid profile, total protein, albumin, bilirubin, heme oxgenase-1 and 8-hydroxydeoxyguanosine levels were measured. Liver tissue sections stained with Hematoxylin-Eosin. Acute or chronic CCl₄-exposure caused to significant changes in concentrations/activities of the measured parameters. The oral administration of extract and probiotics showed protective and therapeutic effects against CCl₄-induced liver-injury. The supplementation of intestinal flora by the use of probiotics may enhance the efficacy of orally given therapeutic extracts.

[Präklinische Untersuchungen von Wechselwirkungen zwischen Mistel und Radio- oder Chemotherapie auf pädiatrische Tumorzellen]

Hintergrund: Mistelanwendungen werden als komplementäre Therapien häufig in der pädiatrischen Onkologie zusammen mit einer Radio- oder Chemotherapie verabreicht. Wechselwirkungen bei simultaner Applikation sind gerade in der Pädiatrie von großer Bedeutung, sie sind allerdings nach wie vor unzureichend untersucht. Material und Methoden: Zytotoxische Effekte des Mistelextraktes abnobaVISCUM Fraxini (aVF) auf LAN-1 Neuroblastomzellen und deren Etoposid- bzw. Cisplatin-resistente Subzelllinien wurden mittels Viabilitätstest untersucht, sowie mögliche Synergieeffekte zwischen aVF und den Chemotherapeutika durch die Softwareprodukte Combenefit und CompuSyn analysiert. Effekte einer Kombinationstherapie aus aVF und Bestrahlung auf SH-SY5Y Zellen wurden mittels Koloniebildungstest untersucht und Auswirkungen auf die Reparatureffizienz strahleninduzierter Doppelstrangbrüche mit Hilfe durchflusszytometrischer Quantifizierungen von γ-H2AX-Foci nach PI/FITC Doppelfärbung analysiert. Ergebnisse: Die Chemotherapie-resistenten LAN-1 Subzelllinien erwiesen sich als resistenter gegenüber der Mistelbehandlung als die Ursprungszelllinie. Auf Basis vier verschiedener Referenz-modelle konnten vor allem synergistisch/additive Effekte zwischen aVF und den Zytostatika Etoposid und Cisplatin berechnet werden. Die Kombination aus Mistelbehandlung und Bestrahlung führte zu einer Verringerung der Koloniebildung und zu einer Verzögerung der Reparaturgeschwindigkeit von strahleninduzierten Doppelstrangbrüchen. Schlussfolgerung: Die präklinischen Daten könnten darauf hinweisen, dass die Verwendung des Mistelextraktes, aVF, eine unterstützende Wirkung auf Radio- und Chemotherapien hat.

BACKGROUND

Mistletoe therapies belong to the field of complementary medicines and are often administered simultaneously or successive to conventional radio- or chemotherapy. Drug-herb interactions are of great significance, especially in pediatrics, but are still insufficiently investigated.

MATERIAL AND METHODS

Cytotoxic effects of the mistletoe extract, abnobaVISCUM Fraxini (aVF), on LAN-1 neuroblastoma cell line and their chemotherapy-resistant (cisplatin; etoposide) subclones were investigated by cell viability assays. Potential synergistic or antagonistic effects of the co-treatment of aVF and cisplatin or etoposide, respectively, were analyzed by Combenefit and CompuSyn software. Combinational effects of mistletoe and irradiation were assessed by colony formation assays and repair efficiency of irradiation-induced double strand breaks was investigated by flow cytometric analyses of γ-H2AX foci after PI/FITC double staining.

RESULTS

Chemotherapy-resistant subclones were more resistant to mistletoe therapy than the parental cells. Based on four different reference models, primarily synergistic/additive effects between aVF and the cytostatic drugs could be calculated. Simultaneous application of mistletoe extract and irradiation led to a delay of irradiation-induced double strand break repair in neuroblastoma cells and a decreased colony formation compared to irradiation monotherapy.

CONCLUSION

The preclinical data may indicate that the use of aVF has a supportive effect on radio- and chemotherapies.

Long-Term Survival of a Patient with Recurrent Dedifferentiated High-Grade Liposarcoma of the Retroperitoneum Under Adjuvant Treatment with Viscum album L. Extract: A Case Report

Retroperitoneal sarcomas are rare. Dedifferentiated liposarcomas (DDLs) are high-grade tumors with a high propensity for local recurrence and metastasis and are associated with reduced survival. Radical resection remains the standard treatment of sarcomas. Meanwhile, Viscum album L. extract (VAE) is used in cancer patients owing to its cytostatic and immunomodulating effects and to its ability to improve patients’ quality of life.

Viscum album extract (Helixor-M) treatment for thoracic duct injury after modified radical neck dissection: a case report

Chyle leakage after modified radical neck dissection is a rare condition that could be occasionally life-threatening if untreated. We report the first case of successful management of a thoracic duct injury using Viscum album extract (Helixor-M). A 54-year-old woman diagnosed with papillary thyroid cancer of the right lobe of the thyroid with metastasis to cervical lymph node levels II-VI, bilaterally, underwent total thyroidectomy and modified radical neck dissection. Three days postoperatively, the surgical team identified a thoracic duct injury due to drainage of chyle from the Jackson-Pratt drain inserted in the right side of the patient`s neck. Various medical treatments (octreotide, withdrawal of enteral feeding, and total parenteral nutrition) and surgical treatments [lymphatic ligation of cervical lymph node level IV and negative pressure wound therapy (vacuum-assisted closure)] were performed, but the drainage persisted. Viscum album extract (Helixor-M) was then injected through the drain. The dose of Viscum album extract was increased while being cautious of its adverse effects, such as nausea, vomiting, erythema, induration at the injection site, and flu-like symptoms. The injection was effective in stopping the drainage and the patient's condition improved, without recurrence. The patient was discharged on the 64^th postoperative day without any further complications. Our results suggest that treatment of thoracic duct injury after neck surgery with Viscum album extract (Helixor-M) may be a novel, less invasive alternative approach to treat cases resistant to standard treatments.

Advances on the Visualization of the Internal Structures of the European Mistletoe: 3D Reconstruction Using Microtomography

The European mistletoe (Viscum album) is a dioecious epiphytic evergreen hemiparasite that develops an extensive endophyte enabling the absorption of water and mineral salts from the host tree, whereas the exophytic leaves are photosynthetically active. The attachment mode and host penetration are well studied, but little information is available about the effects of mistletoe age and sex on haustorium-host interactions. We harvested 130 plants of Viscum album ssp. album growing on host branches of Aesculus flava for morphological and anatomical investigations. Morphometric analyses of the mistletoe and the (hypertrophied) host interaction site were correlated with mistletoe age and sex. We recorded the morphology of the endophytic systems of various ages by using X-ray microtomography scans and corresponding stereomicroscopic images. For detailed anatomical studies, we examined thin stained sections of the mistletoe-host interface by light microscopy. The diameter and length of the branch hypertrophy showed a positive linear correlation with the age of the mistletoe. Correlations with their sex were only found for ratios between host branch and hypertrophy size. A female bias of about 76% was found. In a 4-year-old mistletoe, several small, almost equally sized sinkers and the connected cortical strands extend over more than 5 cm within the host branch. In older mistletoes, one main sinker was predominant and occupied an increasingly large proportion of the stem cross-section. Bands of vessels ran along the axis of the wedge-shaped haustoria and sinkers and bent sideways toward the mistletoe-host interface. At the interface, the vascular elements of the host wood changed their direction and formed vortices near the haustorium.

Chemical pleurodesis with Viscum album L. extract for secondary spontaneous pneumothorax in elderly patients

Background

Secondary spontaneous pneumothorax is generally managed by surgery, if pneumothorax was not improved following chest tube insertion or in the event of persistent air leakage lasting more than 5 days. However, if surgery is not an option, chemical pleurodesis with sclerosants can be performed. Several sclerosants have been used in the chemical pleurodesis of secondary spontaneous pneumothorax, However, there is still controversy for what is the ideal sclerosant for Secondary spontaneous pneumothorax. The use of Viscum album L. for chemical pleurodesis in patients with secondary spontaneous pneumothorax aged >65 years has not been described to date, despite its extensive use. The authors tried to find out the effect of Viscum album L. for sclerosant for Secondary spontaneous pneumothorax in elder.

Methods

This retrospective analysis examined 25 patients (aged >65 years) with secondary spontaneous pneumothorax with persistent air leakage who underwent chemical pleurodesis with Abnova Viscum-F^® (V. album L.).

Results

The duration of chest tube drainage was 5.08 days after chemical pleurodesis. Adverse effects related to chemical pleurodesis with Abnova Viscum-F^® were fever (7/25), pain (4/25), leukocytosis (10/25), and dyspnea with desaturation (7/25); however all the patients recovered without sequela and were subsequently discharged.

Conclusions

The present study demonstrated the successful use of chemical pleurodesis with V. album L. in the management of elderly patients with secondary spontaneous pneumothorax. Because of the high probability of dyspnea with desaturation in the elderly, caution must be exercised.

Anticancer Effects of Viscum album Fraxini Extract on Medulloblastoma Cells in vitro

BACKGROUND

Mistletoe therapy is frequently administered as a supportive treatment in diverse pediatric cancer entities including brain tumors. Medulloblastoma is the most common brain tumor in childhood. Its high risk to metastasize and its long-term sequelae caused by aggressive chemo- or radiotherapies are still challenging.

MATERIAL AND METHODS

Effects of a lectin-rich mistletoe extract, abnobaVISCUM Fraxini, were investigated in two medulloblastoma cell lines (Daoy and ONS-76). Responsiveness of tumor cells was assessed by cell viability assays and xCELLigence real-time analyses. Moreover, impacts on proliferation, cell cycle and apoptosis were investigated. Apoptosis was studied by staining of vital mitochondria and assessing the involvement of caspases. In addition, effects on migration and invasion were analyzed.

RESULTS

Both medulloblastoma cell lines were more susceptible to treatment with the mistletoe extract than a nontumorigenic fibroblast cell line. In mistletoe-sensitive Daoy cells, reduction of proliferation and induction of caspase-mediated apoptosis were observed upon administration of 0.05 and 0.5 mg/mL abnobaVISCUM Fraxini treatment, respectively. Furthermore, mistletoe extract inhibited migration and invasion properties in Daoy and significantly impaired invasive capabilities of ONS-76 cells.

CONCLUSION

AbnobaVISCUM Fraxini has cell line dependent antitumoral effects in medulloblastoma models. These results call for further investigations, to reveal mechanistic insights into antitumorigenic properties of mistletoe extracts.

A Systematic Review and Meta-Analysis on the Survival of Cancer Patients Treated with a Fermented Viscum album L. Extract (Iscador): An Update of Findings

PURPOSE

We aimed at updating the evidence found in controlled studies addressing general and event-free survival of cancer patients treated with the fermented mistletoe extract Iscador.

METHODS

The databases Embase, PubMed, CAMbase, Scopus, AMED and Cochrane were searched for clinical studies on cancer patients treated with Iscador. Quality of studies and risk of bias were evaluated according to the Cochrane guidelines and the Newcastle Ottawa Scale. Outcome data were expressed as hazard ratios (HR) and the respective 95% confidence intervals (CI). Meta-analysis was carried out using a random-effects model.

RESULTS

Eighty-two controlled studies met the inclusion criteria, of which 32 with 55 strata provided data for extracting HR and CI. The overall HR was 0.59 (95% CI: [0.53; 0.65], p < 0.0001) in favour of Iscador treatment. Heterogeneity of study results was moderate (I2 = 50.9%; p < 0.0001, τ2 = 0.053). Meta-regression did not reveal significant effects of sample size or study design. However, significant differences were found between cancer entities (p < 0.01), with most pronounced effects in cervical (HR = 0.43) and less pronounced effects in lung cancer (HR = 0.84).

CONCLUSIONS

We found almost identical effects on cancer survival based on a broader database of higher quality. However, none of the studies was blinded and, therefore, there might be risk of performance bias. Implications for cancer survivors are as follows: findings indicate that adjuvant treatment of cancer patients with Iscador can be associated with a better survival.

Chemoimmunotherapy in Advanced Renal Cell Carcinoma: A Case Report of a Long-Term Survivor Adjunctly Treated with Viscum album Extracts

INTRODUCTION

Metastatic renal cell carcinoma has a poor prognosis. Treatment approaches with immunotherapy show promising results in subpopulations. Viscum album extracts - used as an adjunct to cancer treatment - have cytotoxic, apoptogenic, and immune-stimulating properties and show synergistic effects with chemotherapy agents.

CASE REPORT

A 51-year-old man was diagnosed with metastatic renal cell carcinoma of clear cell histology which was classified as pT3a, N1, M1, G3. Nephrectomy was performed, and the patient received chemoimmunotherapy (interferon-α2a, interleukin-2, fluorouracil, isotretinoin). Additionally, he received V. album extracts as intravenous infusions and subcutaneous injections. One year after surgery, the patient was in complete remission, which is ongoing 18 years after the initial diagnosis.

DISCUSSION

This case shows an extraordinarily long survival of a metastasized renal cell carcinoma patient under chemoimmunotherapy and fever-inducing V. album extracts. This combined treatment might have synergistically contributed to tumor remission and control. With regard to clinical relevance, further investigations are needed.

Mistletoe Versus Host Pine: Does Increased Parasite Load Alter the Host Chemical Profile?

Stress caused by parasitic plants, e.g. mistletoes, alters certain host-plant traits as a response. While several physical implications of the parasite-host relation have been well studied, shifts in the host chemical profile remain poorly understood. Here we compare the chemical profiles of mistletoe (Viscum album subsp. austriacum) leaves and host pine (Pinus nigra subsp. salzmannii) needles and we investigate chemical changes in host needles of trees with different parasite loads (control, low, medium, and high). Our results reveal that despite the intimate contact between mistletoe and host pine, their chemical profiles differed significantly, revealing extremely low concentrations of defense compounds (including a complete lack of terpenes) and high levels of N concentrations in mistletoe leaves. On the other hand, parasitized pines showed unique chemical responses depending on parasite loads. Overall, the content in monoterpenes increased with parasitism. Higher parasitized pines produced higher amounts of defense compounds (phenols and condensed tannins) than less parasitized trees, but amounts in samples of the same year did not significantly differ between parasitized and unparasitized pines. Highly parasitized pines accumulated less N than pines with other parasite loads. The strongest response was found in sesqui- and diterpenes, which were at lower levels in pines under medium and high parasitism. Chemical responses of pines to mistletoe parasitism resembled reactions to other kinds of stress. Low levels induced reactions resembling those against drought stress, while medium and high parasitism elicited responses comparable to those against burning and defoliation.

Complete Remission and Long-term Survival of a Patient with a Diffuse Large B-cell Lymphoma Under Viscum album Extracts After Resistance to R-CHOP: A Case Report

BACKGROUND

A nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL) is a lymphoproliferative neoplasm with a fair prognosis, but the possibility of a malignant transformation into a diffuse large B-cell lymphoma (DLBCL) is high. DLBCL progresses aggressively. Introduction of rituximab into therapy had led to improved outcomes. The use of Viscum album extracts (VAE) in cancer is established, but their application in lymphoma are rare.

CASE PRESENTATION

A 65-year-old patient was diagnosed with DLBCL stage IIa with splenomegaly, transformed from a NLPHL, after a 30-year history of repeatedly enlarged inguinal lymph nodes. The patient initially rejected chemotherapy. After his tumor pain increased, he accepted the consecutive therapies bendamustine plus vincristine plus prednisolone, trofosfamide, and rituximab plus cyclophosphamide plus hydroxydaunorubicin plus vincristine plus prednisone (R-CHOP), inducing only a slight regression of the splenic lesions. VAE was additionally applied to R-CHOP. Five months after termination of chemotherapy - under continued VAE therapy in increasing dosage- regression of paraaortal lesions was found. The patient fully recovered under continuous VAE application and is in ongoing complete remission and in a good state of health 17 years after the initial diagnosis.

CONCLUSION

As complete remission of lymphoproliferative disorders after VAE treatment has been previously reported, further investigations of VAE in lymphoma seem highly worthwhile.

Durable clinical remission of a skull metastasis under intralesional Viscum album extract therapy: Case report

Background

Skull metastases are rare, they can eventually cause pain, and can invade the brain. Viscum album extracts (VAEs) are used as an adjuvant treatment in cancer.

Methods and Results

A 68‐year‐old patient with rectal cancer presented with lung metastases, and metastases to multiple bone sites, the chest wall, and the liver were later identified. Histological examination of one of the bone lesions revealed an additional thyroid carcinoma. An osteolytic parietal bone lesion progressed to a painful metastasis of the skull despite radiotherapy and chemotherapy. The VAEs were applied weekly into the metastasis, followed by pain relief and softening of the lesion. The lesion partially regressed (>50%) after 8 months of continued VAE treatment and remained stable for 2 years.

Conclusion

This case shows a durable clinical remission of a skull metastasis under VAE. Further investigations of intratumoral VAE treatment seem worthwhile—especially in symptomatic skull metastases not responding to radiotherapy or systemic therapies.

Absence of Complex I Implicates Rearrangement of the Respiratory Chain in European Mistletoe

The mitochondrial oxidative phosphorylation (OXPHOS) system, which is based on the presence of five protein complexes, is in the very center of cellular ATP production. Complexes I to IV are components of the respiratory electron transport chain that drives proton translocation across the inner mitochondrial membrane. The resulting proton gradient is used by complex V (the ATP synthase complex) for the phosphorylation of ADP. Occurrence of complexes I to V is highly conserved in eukaryotes, with exceptions being restricted to unicellular parasites that take up energy-rich compounds from their hosts. Here we present biochemical evidence that the European mistletoe (Viscum album), an obligate semi-parasite living on branches of trees, has a highly unusual OXPHOS system. V. album mitochondria completely lack complex I and have greatly reduced amounts of complexes II and V. At the same time, the complexes III and IV form remarkably stable respiratory supercomplexes. Furthermore, complexome profiling revealed the presence of 150 kDa complexes that include type II NAD(P)H dehydrogenases and an alternative oxidase. Although the absence of complex I genes in mitochondrial genomes of mistletoe species has recently been reported, this is the first biochemical proof that these genes have not been transferred to the nuclear genome and that this respiratory complex indeed is not assembled. As a consequence, the whole respiratory chain is remodeled. Our results demonstrate that, in the context of parasitism, multicellular life can cope with lack of one of the OXPHOS complexes and give new insights into the life strategy of mistletoe species.

Absence of Complex I Is Associated with Diminished Respiratory Chain Function in European Mistletoe

Parasitism is a life history strategy found across all domains of life whereby nutrition is obtained from a host. It is often associated with reductive evolution of the genome, including loss of genes from the organellar genomes [1, 2]. In some unicellular parasites, the mitochondrial genome (mitogenome) has been lost entirely, with far-reaching consequences for the physiology of the organism [3, 4]. Recently, mitogenome sequences of several species of the hemiparasitic plant mistletoe (Viscum sp.) have been reported [5, 6], revealing a striking loss of genes not seen in any other multicellular eukaryotes. In particular, the nad genes encoding subunits of respiratory complex I are all absent and other protein-coding genes are also lost or highly diverged in sequence, raising the question what remains of the respiratory complexes and mitochondrial functions. Here we show that oxidative phosphorylation (OXPHOS) in European mistletoe, Viscum album, is highly diminished. Complex I activity and protein subunits of complex I could not be detected. The levels of complex IV and ATP synthase were at least 5-fold lower than in the non-parasitic model plant Arabidopsis thaliana, whereas alternative dehydrogenases and oxidases were higher in abundance. Carbon flux analysis indicates that cytosolic reactions including glycolysis are greater contributors to ATP synthesis than the mitochondrial tricarboxylic acid (TCA) cycle. Our results describe the extreme adjustments in mitochondrial functions of the first reported multicellular eukaryote without complex I.

Phenolic compounds from Viscum album tinctures enhanced antitumor activity in melanoma murine cancer cells

Cancer is one of the biggest problems in public health worldwide. Plants have been shown important role in anticancer research. Viscum album L. (Santalaceae), commonly known as mistletoe, is a semi-parasitic plant that grows on different host trees. In complementary medicine, extracts from European mistletoe (Viscum album L.) have been used in the treatment of cancer. The study was conducted to identify chemical composition and antitumor potential of Viscum album tinctures. Chemical analysis performed by high resolution chromatography equipped with high resolution mass spectrometer identified caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A compounds. Some of these compounds are probably responsible for the reduction of tumoral cellular growth in a dose-dependent manner. It was observed that melanoma murine cells (B16F10) were more sensitive to V. album tinctures than human leukaemic cells (K562), besides non-tumoral cells (MA-104) had a much lower cytotoxicity to them. Apoptotic-like cells were observed under light microscopy and were confirmed by a typical DNA fragmentation pattern. Additionally, flow cytometry results using Annexin-V/FITC permitted to quantify increased expression of early and late apoptotic markers on tumoral cells, confirming augmented Sub G0 population, which was probably associated with a consistent decrease in G1, and an increase in S or G2/M populations. Results indicate the chemical composition of V. album tinctures influences the mechanisms of in vitro tumoral cell death, suggesting a potential use in cancer pharmacotherapy research.

Effects of mistletoe products on pharmacokinetic drug turnover by inhibition and induction of cytochrome P450 activities

Background

European mistletoe (Viscum album) products used in cancer therapy are frequently combined with other anti-cancer-drugs. Hence, potential herb-drug interactions have become a major safety concern in mistletoe therapy.

Methods

Three European mistletoe products (Helixor® A, Helixor® M and Helixor® P from mistletoe grown on firs, apple trees and pines, respectively) were tested for inhibition of nine major cytochrome P450 (CYP) isoenzymes in a test system using pooled human liver microsomes and for induction of five CYP isoforms in human hepatocytes cultivated in vitro according to the relevant guideline.

Results

Major inhibition did not occur in any of the CYP marker reactions. For some CYP isoenzymes, a minor or intermediate inhibition could be observed, but without dose effect relationship. Induction activity (≥ 1.5-fold increase) was not found with any of the three mistletoe products.

Conclusion

Since no induction capacity was found and major inhibition above 50% did not occur even with the highest concentration used, which is approximately 100,000-fold higher than the clinically relevant dose in plasma, a clinically relevant herb-drug interaction is not expected for Helixor® A, M, and P.

Safety of intravenously applied mistletoe extract - results from a phase I dose escalation study in patients with advanced cancer

Background

Mistletoe extracts have anti-tumor properties and are approved for subcutaneous use in cancer patients. Data on Intravenous application are limited.

Methods

An aqueous extract from pine-mistletoe was used to investigate maximum tolerable dose (MTD) and safety of intravenous application. It was infused once weekly for 3 weeks in patients with advanced cancer. Any type of cancer was included; relevant exclusion criteria were concurrent chemo- or radiation therapy. The classical phase I 3 + 3 dose escalation scheme was followed. Predefined dose groups were 200, 400, 700, 1200 and 2000 mg. Maximum planned dose was 2000 mg. With the MTD three more patients should be treated for 9 weeks in order to evaluate intermediate term tolerability. Weekly during the treatment and 1 week later tolerability, clinical status, safety laboratory parameters and adverse events were documented.

Results

Twenty-one patients (3 in the dose groups 200, 400, 700 and 1200 mg, respectively, 9 in the dose group 2000 mg) were included. MTD was not reached. Because one dose-limiting toxicity (DLT), an allergic reaction, occurred during infusion of 2000 mg, three more patients had to be included in this dose group and tolerated it, as well as the three patients who received 2000 mg for 9 weeks. Occasionally in the dose group 2000 mg mild to moderate fever occurred.

Conclusion

Weekly infusions of 2000 mg of the pine-mistletoe extract were tolerated and can be used in further studies but had a risk for allergic reactions and fever. German Clinical Trials Register (Trial registration number DRKS00005028).

Cardioprotective effects of Viscum album L. subsp. album (European misletoe) leaf extracts in myocardial ischemia and reperfusion

ETHNOPHARMACOLOGICAL RELEVANCE

Viscum album L. (European mistletoe) is a hemiparasitic plant belonging to Loranthaceae family and has been used in Turkish traditional medicine for the treatment of cardiovascular disorders and heart diseases such as hypertension, tachycardia and angina pectoris.

AIM OF THE STUDY

The present study investigated the cardioprotective effects of V. album leaf extracts in myocardial ischemia and reperfusion injury in rats.

MATERIAL AND METHODS

Lyophilized aqueous (AVa) and methanolic (MVa) extracts of V. album were prepared from dried leaf. The isolated hearts were perfused with V. album extracts prior to and during 35min of ischemia induced by coronary artery occlusion. After 120min of coronary reperfusion, infarct size was determined by triphenyltetrazolium staining.

RESULTS

Both AVa and MVa extracts reduced the extent of infarction compared with untreated control hearts, but protective effect of MVa had more potential in low concentration; infarct size as proportion of ischemic risk zone: AVa 17.5±1.5%; Mva 20.3±2.5%, both P<0.01 versus control 38.1±1.4%. This protective effect was comparable to infarct limitation induced by ischemic preconditioning (21.5±2.4%). Inhibition of nitric oxide synthesis with L-N^G-nitroarginine methyl ester completely abrogated the protection afforded by both extracts. ATP-sensitive K⁺ channel blockade by glibenclamide abrogated the protection afforded by MVa while attenuating, but not abolishing, the protective action of Ava.

CONCLUSIONS

This study provided the first experimental evidence that V. album leaf extracts can mediate nitric oxide-dependent cardioprotection against myocardial injury produced by ischemia/reperfusion insult. With this study, popular usage of V. album extracts in Turkish folk medicine as a remedy for cardiac diseases was justified.

Chemical Pleurodesis Using Doxycycline and Viscum album Extract

Background

In chemical pleurodesis for managing pulmonary air leak, tetracycline derivatives are commonly used, and their effectiveness has been established in many studies. Recently, a Viscum album extract was used in chemical pleurodesis. We compared the effects of V. album with those of a tetracycline derivative (doxycycline) to demonstrate the therapeutic effectiveness of the V. album extract in chemical pleurodesis for managing pulmonary air leak.

Methods

Between October 2010 and October 2016, chemical pleurodesis was performed using doxycycline in 40 patients and the V. album extract in 37 patients. Thirty-three patients were in the postoperative state after pulmonary resection, and 44 patients suffered from spontaneous pneumothorax.

Results

No statistically significant difference in the success rate was observed between the 2 groups (V. album extract and doxycycline). In both groups, chest pain was the most common complication. More patients in the doxycycline group complained of severe chest pain (42.1% vs. 13.5%, p=0.006). In the V. album extract group, 24.3% of the patients required a chest tube to drain the pleural effusion after cessation of the air leak (doxycycline group: 5%, p=0.022). Further, the amount of pleural effusion drained on the day after the last chemical pleurodesis in the V. album extract group was greater than that in the doxycycline group (162.2±170.2 mL vs. 97.0±77.2 mL, p=0.032). All patients were discharged from the hospital without complications after pleural effusion drainage.

Conclusion

Considering that treatment using the V. album extract was less painful, V. album might be a feasible option for chemical pleurodesis. However, pleural effusion should be monitored carefully when using V. album extract for treating patients suffering from air leak.

Viscum album (L.) in experimental animal tumors: A meta-analysis

Mistletoe (Viscum album L.) has been used as complementary anticancer treatment for ~100 years. Although the clinical efficacy of mistletoe in cancer and associated survival benefits remain contested, several studies point to its effectiveness and others have reported antitumor and immunomodulatory properties. In the present review, a search was conducted for original articles reporting the outcomes of treatments for experimental animal tumors with mistletoe. The inclusion criteria were: Publication in English, from 1996 onwards and in peer-reviewed journals included in the database PubMed. The parameters analyzed were: Provenance and time of publication, rationale, methods (animal species used, mistletoe preparation, treatment protocol, tumor lineage, blinding, randomization, controls and concomitant treatments), outcomes and investigated mechanisms of action. A total of 37 studies met the inclusion criteria. The quality of the studies was adequate in the terms of sample size and use of controls, and the only animal species employed were mice and rats. However, few studies reported having performed random allocation and none reported blinding. There was wide variation in the type and preparation of mistletoe used, route of administration, regimen, tumor type and the mechanism of action assessed. A temporal trend was identified; earlier studies sought to establish the antitumor effect of mistletoe and its possible mechanisms, cytotoxicity and immunomodulation in particular, whereas the later ones tended to focus more on biologically active principles, genomics and oxidative stress. A total of 32/37 studies reported an antitumor effect, 3 of which had mixed results. A total of 2 studies did not detect any antitumor effect and a further 2 found stimulation of tumor growth in the treated groups. One study did not assess antitumor effects, investigating immunomodulation action instead. The quality of the studies was satisfactory and the majority reported positive outcomes. Nevertheless, there is a great deal of methodological heterogeneity among the studies, which precludes conclusive comparisons. Based on these results, the present authors strongly suggest developing guidelines for reporting in vivo mistletoe cancer treatment experiments.

Acute Respiratory Distress Syndrome after Viscum album Pleurodesis for Primary Spontaneous Pneumothorax

A 52-year-old male patient who underwent multiple wedge resections experienced postoperative acute respiratory distress syndrome in both lungs after Viscum album pleurodesis. Despite initial rapid deterioration in clinical condition and rapid progression of bilateral lung infiltration, he exhibited a relatively smooth clinical recovery with marked response to glucocorticoid treatment. Our case report suggests that care must be taken to guard against the development of acute respiratory complications in the use of Viscum album for pleurodesis. However, in view of the clinically benign course, initial aggressive management of complications can prevent suffering and sequelae.

The prophylactic effect of Viscum album in streptozotocin-induced diabetic rats

OBJECTIVE

Viscum album (VA) is a species of mistletoe in the family Santalaceae that is thought to have therapeutic properties for several diseases, including diabetes. In the present study, conventional experimental rat model was used with diabetes induced with streptozotocin (STZ) to evaluate effect of VA on lipid peroxidation and antioxidant system.

METHODS

Total of 32 adult, male Sprague-Dawley rats were divided into 4 groups of 8 rats: Control group, STZ group, VA group, and group administered VA+STZ. VA extract was 100 mg/kg preparation delivered once a day by oral gavage for 10 days. Single dose of 55 mg/kg STZ citrate buffer (0.1 M, pH 4.5) was administered intraperitoneally to induce diabetes. Fasting blood glucose level was measured and recorded. Animals were sacrificed, and catalase (CAT), malondialdehyde (MDA), and protein present in liver and kidney tissue samples were measured. Activity of CAT, an antioxidant enzyme, was studied according to the Aebi method. MDA, a product of lipid peroxidation, was analyzed using Draper and Hadley spectrophotometric procedure. Protein level was determined using supernatant and extract of tissue homogenates according to Lowry method. Data were assessed using one-way analysis of variance and pairwise comparisons between groups. Post-hoc analysis included Dunnet test, Duncan test, and least significant difference test. P<0.05 was considered significant probability value.

RESULTS

Oxidative stress is associated with diabetic complications. VA administered to diabetic rats reduced oxidative stress and improved their general condition.

CONCLUSION

Further studies are needed to enhance understanding of potential antidiabetic and antioxidant effects of VA.

Health services research of integrative oncology in palliative care of patients with advanced pancreatic cancer

BACKGROUND

Pancreatic cancer has a dire prognosis and is associated with a high mortality. Palliative patients have special needs and often seek help in integrative oncological concepts (IO) that combine conventional and complementary therapies. Nevertheless there are few recommendations regarding IO in current cancer guidelines. The aims of this study were to report on implementation of IO in everyday palliative care and to analyze patient survival in advanced pancreatic cancer.

METHODS

This multicenter observational study investigates the implementation of IO and length of survival of patients suffering from advanced pancreatic cancer (stage IV). We analyzed patient's survival by employing multivariable proportional hazard models using different parametric distribution functions and compared patients receiving chemotherapy only, a combination of chemotherapy and Viscum album (VA) treatment, and VA treatment only.

RESULTS

Records of 240 patients were analyzed. Complementary therapy showed high acceptance (93 %). Most frequent therapy was VA treatment (74 %) that was often administered concomitantly to chemotherapy (64 %). Both therapies had positive effects on patient survival as they had significant negative effects on the hazard in our log-normal model. A second analysis showed that patients with combined chemotherapy and VA therapy performed significantly better than patients receiving only chemotherapy (12.1 to 7.3 month). Patients receiving only VA therapy showed longer survival than those receiving neither chemotherapy nor VA therapy (5.4 to 2.5 months). Our data demonstrates that IO can be implemented in the everyday care of patients without disregarding conventional treatment. Patients combining VA with chemotherapy showed longest survival.

CONCLUSIONS

Our data demonstrate the importance and potential of health services research showing that IO treatment can be successfully implemented in the every-day care of patients suffering from advanced pancreatic cancer. Patients combining VA with chemotherapy showed longest survival. To address patients' needs adequately, future cancer guidelines might increasingly include comments on complementary treatment options in addition to conventional therapies. Further studies should investigate the effect of complementary treatments on survival and quality of life in more detail.

Intestinal and vascular smooth muscle relaxant effect of Viscum album explains its medicinal use in hyperactive gut disorders and hypertension

Background

Viscum album has shown inhibitory effect on different smooth muscles but underlying mechanisms in gut and vascular smooth muscles are not well defined. Additionally, the plant has also importance in managing hyperactive gut and cardiovascular disorders. The current study was aimed to probe a pharmacological base of the smooth muscle relaxant effect of V. album in gut and vascular preparations.

Methods

V. album crude extract (Va. Cr) and its ethyl acetate fraction (Va. EtAc) were studied using in vitro techniques. The antispasmodic activity was performed using isolated rabbit jejunum while the vasorelaxant effects were studied in rabbit aortic rings.

Results

Va. Cr and Va. EtAc inhibited spontaneous and high K⁺-induced contractions with EC₅₀ values of 0.31 mg/mL (0.15–0.57) and 0.62 mg/mL (0.3–0.95), respectively. This advocates an antispasmodic effect probably operated through calcium channels blockade (CBB). The proposed mechanism was confirmed by a pretreatment of the tissue with Va. Cr (0.01–0.3 mg/mL), which shifted the Ca⁺⁺ concentration-response curves (CRCs) rightward, similar to verapamil. Moreover, Va. Cr showed a partial relaxation against high K⁺ and PE (1 μM) induced contractions in isolated rabbit aorta rings. Va. EtAc caused complete relaxation of high K⁺ precontraction and partially relaxed PE (1 μM) induced contractions, suggesting inhibitory effect on Ca⁺⁺ entry, in addition to other possible mechanisms. CRCs were shifted to the right correspondingly to verapamil when the aortic rings were pretreated with Va. Cr and Va. EtAc.

Conclusions

These data indicated that Va. Cr possesses smooth muscle relaxant effect mediated through voltage-dependent Ca⁺⁺ channel blockade (CCB), which explains its spasmolytic and vasorelaxant activity. The CCB activity is concentrated more in Va. EtAc. This study provides an evidence for the medicinal importance of V. album in gut spasm and possibly hypertension.

Differential Effects of Viscum album Preparations on the Maturation and Activation of Human Dendritic Cells and CD4⁺ T Cell Responses

Extracts of Viscum album (VA); a semi-parasitic plant, are frequently used in the complementary therapy of cancer and other immunological disorders. Various reports show that VA modulates immune system and exerts immune-adjuvant activities that might influence tumor regression. Currently, several therapeutic preparations of VA are available and hence an insight into the mechanisms of action of different VA preparations is necessary. In the present study, we performed a comparative study of five different preparations of VA on maturation and activation of human dendritic cells (DCs) and ensuing CD4⁺ T cell responses. Monocyte-derived human DCs were treated with VA Qu Spez, VA Qu Frf, VA M Spez, VA P and VA A. Among the five VA preparations tested VA Qu Spez, a fermented extract with a high level of lectins, significantly induced DC maturation markers CD83, CD40, HLA-DR and CD86, and secretion of pro-inflammatory cytokines such as IL-6, IL-8, IL-12 and TNF-α. Furthermore, analysis of T cell cytokines in DC-T cell co-culture revealed that VA Qu Spez significantly stimulated IFN-γ secretion without modulating regulatory T cells and other CD4⁺ T cytokines IL-4, IL-13 and IL-17A. Our study thus delineates differential effects of VA preparations on DC maturation; function and T cell responses.

Fever Therapy With Intravenously Applied Mistletoe Extracts for Cancer Patients: A Retrospective Study

Purpose. So-called spontaneous remissions in cancer often seem to occur after febrile events. Mistletoe preparations (MPs) are used off-label intravenously to induce fever within concepts of integrative oncology. We wanted to investigate the frequency of febrile reactions and safety related to intravenously applied MPs (IAMPs). Methods. This was a retrospective analysis of data from consecutive cancer patients who were treated in 2 anthroposophic hospitals with IAMPs. The main outcome parameter was the rate of core temperature increase to ≥38.5°C within 24 hours after IAMPs. Secondary outcome parameters were Common Toxicity Criteria for Adverse Events (CTCAE; version 4.0). Results. 59 patients, with in total 567 IAMPs, were analyzed; 45 patients (76%, 95% CI = 65%-87%) had an increase of core temperature to ≥38.5°C after at least 1 treatment. Mean increase in temperature was 1.5°C ± 0.8°C. Adverse events were mostly fever-related symptoms (headache, joint pain, shivering). Grade 1 allergic reactions were documented in 0.6% of treatments. CTCAEs grade 3 to 5 did not occur; 38/59 patients had advanced and/or metastatic disease. Conclusion. IAMPs resulted in febrile reactions to >38.5°C in the majority of patients and can be considered as safe. Adverse events were mostly related to fever and were not severe.