Untargeted metabolomics approach to discriminate mistletoe commercial products

Multiplatform untargeted metabolomics

Metabolomics samples like human urine or serum contain upwards of a few thousand metabolites, but individual analytical techniques can only characterize a few hundred metabolites at best. The uncertainty in metabolite identification commonly encountered in untargeted metabolomics adds to this low coverage problem. A multiplatform (multiple analytical techniques) approach can improve upon the number of metabolites reliably detected and correctly assigned. This can be further improved by applying synergistic sample preparation along with the use of combinatorial or sequential non-destructive and destructive techniques. Similarly, peak detection and metabolite identification strategies that employ multiple probabilistic approaches have led to better annotation decisions. Applying these techniques also addresses the issues of reproducibility found in single platform methods. Nevertheless, the analysis of large data sets from disparate analytical techniques presents unique challenges. While the general data processing workflow is similar across multiple platforms, many software packages are only fully capable of processing data types from a single analytical instrument. Traditional statistical methods such as principal component analysis were not designed to handle multiple, distinct data sets. Instead, multivariate analysis requires multiblock or other model types for understanding the contribution from multiple instruments. This review summarizes the advantages, limitations, and recent achievements of a multiplatform approach to untargeted metabolomics.

Multiplatform untargeted metabolomics

Metabolomics samples like human urine or serum contain upwards of a few thousand metabolites, but individual analytical techniques can only characterize a few hundred metabolites at best. The uncertainty in metabolite identification commonly encountered in untargeted metabolomics adds to this low coverage problem. A multiplatform (multiple analytical techniques) approach can improve upon the number of metabolites reliably detected and correctly assigned. This can be further improved by applying synergistic sample preparation along with the use of combinatorial or sequential non-destructive and destructive techniques. Similarly, peak detection and metabolite identification strategies that employ multiple probabilistic approaches have led to better annotation decisions. Applying these techniques also addresses the issues of reproducibility found in single platform methods. Nevertheless, the analysis of large data sets from disparate analytical techniques presents unique challenges. While the general data processing workflow is similar across multiple platforms, many software packages are only fully capable of processing data types from a single analytical instrument. Traditional statistical methods such as principal component analysis were not designed to handle multiple, distinct data sets. Instead, multivariate analysis requires multiblock or other model types for understanding the contribution from multiple instruments. This review summarizes the advantages, limitations, and recent achievements of a multiplatform approach to untargeted metabolomics.

The Antioxidant Activity of Mistletoes (Viscum album and Other Species)

In addition to the European mistletoe, Viscum album, which is the most known and utilized one, there are several species commonly known as mistletoe. They are spread in various regions of the planet and are all characterized by hemiparasitism and epiphytic behaviour. The published studies evidence other similarities, including the sharing of important biological properties, with the common presence of antioxidant effects. However, whereas the European mistletoe is largely utilized in medical treatments, although with controversial aspects, the scientific knowledge and medical uses of other mistletoes are still insufficient. This review focuses on the controversial medical story of European mistletoe regarding its antioxidant activity and the potentiality of the other species named mistletoe pertaining to botanical families and genera different from Viscum.

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.

Detecting and Profiling of Milk Thistle Metabolites in Food Supplements: A Safety-Oriented Approach by Advanced Analytics

Milk thistle (Silybum marianum (L.) Gaertn.) is among the top-selling botanicals used as a supportive treatment for liver diseases. Silymarin, a mixture of unique flavonolignan metabolites, is the main bioactive component of milk thistle. The biological activities of silymarin have been well described in the literature, and its use is considered safe and well-tolerated in appropriate doses. However, commercial preparations do not always contain the recommended concentrations of silymarin, failing to provide the expected therapeutic effect. While the poor quality of raw material may explain the low concentrations of silymarin, its deliberate removal is suspected to be an adulteration. Toxic contaminants and foreign matters were also detected in milk thistle preparations, raising serious health concerns. Standard methods for determination of silymarin components include thin-layer chromatography (TLC), high-performance thin-layer chromatography (HPTLC), and high-performance liquid chromatography (HPLC) with various detectors, but nuclear magnetic resonance (NMR) and ultra-high-performance liquid chromatography (UHPLC) have also been applied. This review surveys the extraction techniques of main milk thistle metabolites and the quality, efficacy, and safety of the derived food supplements. Advanced analytical authentication approaches are discussed with a focus on DNA barcoding and metabarcoding to complement orthogonal chemical characterization and fingerprinting of herbal products.

The Introspective Patient Experience of Mistletoe Therapy in Cancer: A Qualitative Study

INTRODUCTION

The introspective experience of cancer patients using mistletoe therapy has received little scientific interest, although it is crucial for a holistic understanding of this therapy. This study contributes to patient-centered research and treatment by documenting the subjective experiences of individuals undergoing mistletoe therapy.

METHODS

In this qualitative, explorative study, 20 outpatients with a history of various cancer types were recruited from Arlesheim Hospital (Arlesheim, Switzerland). All patients received subcutaneous mistletoe therapy for at least 2 years (median 7.5 years). Data was collected through 2 semi-structured, in-depth interviews per patient. Qualitative content analysis was applied to examine the data. The individual experience of mistletoe therapy was analyzed in relation to 6 predefined levels of human experience: physical, vital, emotional, mental, spiritual and social. In addition, 3 further aspects, considered as cross-dimensional perspectives, emerged out of the material: warmth, immune strengthening, and general wellbeing.

RESULTS

Data analysis revealed considerable heterogeneity among patients' experiences with mistletoe therapy. The importance of specific aspects became apparent, such as increased vitality to manage daily life, greater emotional and mental stability, warmth as a multidimensional phenomenon, feelings of safety and protection through mistletoe therapy, heightened self-awareness and improved self-care, as well as sensations of spiritual connectedness.

CONCLUSIONS

Prior to this study it had not been shown that cancer patients using mistletoe therapy do have observations on different levels of experience. These results may lead to a deeper understanding of patients receiving mistletoe therapy, enabling them to be supported in a more holistic way both during mistletoe treatment and on their life path. Further investigations into the effects of mistletoe therapy on the emotional, mental, and spiritual level are warranted.

The Argentine mistletoes Ligaria cuneifolia (Ruiz & Pav.) Tiegh (Loranthaceae) and Phoradendron liga (Gillies ex Hook. & Arn.) Eichler (Santalaceae). Thirty years of research

Ligaria cuneifolia (Ruiz & Pav.) Tiegh (Loranthaceae) and Phoradendron liga (Gillies ex Hook. & Arn.) Eichler (Santalaceae) are regarded as Argentine mistletoes based on their similarities with the European counterpart, Viscum album L. (Santalaceae). These two species are the most used medicinal plants to treat high blood pressure in the Argentinian population. To provide scientific grounds to their traditional use and therapeutic potential, they were selected as herbal drug candidates. The main findings would support the anti-hypertensive action, the anticholesterolemic and antioxidant features of L. cuneifolia, and immunomodulatory properties for both species. Quercetin-O-glycosides, galloyl glycosides, and proanthocyanidins are present in L. cuneifolia while P. liga shows C-glycosyl flavones and 3-deoxyproanthocyanidins. This review summarizes the phytochemical characterization, medicinal properties and reveals promising results warranting future efforts for further investigation.

Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database

Cancer patients could combine herbal treatments with their chemotherapy. We consulted VigiBase, a WHO database of individual case safety reports (ICSRs) which archives reports of suspected Adverse Drug Reactions (ADRs) when herbal products are used in conjunction with anti-cancer treatment. We focused on the possible interactions between antineoplastic (L01 ATC class) or hormone antagonists (L02B ATC class) with 10 commonly used herbs (pineapple, green tea, cannabis, black cohosh, turmeric, echinacea, St John’s wort, milk thistle and ginger) to compare ADRs described in ICSRs with the literature. A total of 1057 ICSRs were extracted from the database but only 134 were complete enough (or did not concern too many therapeutic lines) to keep them for analysis. Finally, 51 rationalizable ICSRs could be explained, which led us to propose a pharmacokinetic or pharmacodynamic interaction mechanism. Reports concerned more frequently women and half of the rationalizable ICSRs involved Viscum album and Silybum marianum. 5% of the ADRs described could have been avoided if clinicians had had access to the published information. It is also important to note that in 8% of the cases, the ADRs observed were life threatening. Phytovigilance should thus be considered more by health care professionals to best treat cancer patients and for better integrative care.

Sakuranetin interacting with cell membranes models: Surface chemistry combined with molecular simulation

Sakuranetin, a natural compound with activity in lipidic biointerfaces, was isolated from Baccharis retusa and studied with two models of lipid membranes: Langmuir monolayers and Molecular Simulation. For that, the mammalian lipid DPPC was chosen. Sakuranetin condensed the monolayers at high surface pressures, decreased the surface compressional modulus, reduced the molecular order of the acyl chains (diminution of all-trans/gauche conformers ratio), and increased the heterogeneity of the interface, forming aggregates. Molecular simulation data gave information on the bioactive compound's most favorable thermodynamic positions along the lipid monolayer, which was the lipid-air interface. These combined results lead to the conclusion that this lipophilic compound may interact with the lipidic layers, preferentially at the lipid-air interface, to minimize the free energy, and reaches this conformation disturbing the thermodynamic, structural, mechanical, rheological, and morphological properties of the well-packed DPPC monolayer.

Survival of Cancer Patients Treated with Non-Fermented Mistletoe Extract: A Systematic Review and Meta-Analysis

Background:

Mistletoe extracts (ME) are used in integrative cancer care to improve quality of life and to prolong survival. ME are available from different producers and differ in pharmaceutical processing, such as fermentation. In contrast to fermented ME, the impact of unfermented extracts on the survival of cancer patients has not yet been assessed in a meta-analysis.

Methods:

We searched the databases Embase, CENTRAL, Europe PMC, Clinicaltrials.gov, Opengrey and Google Scholar, and selected controlled studies on cancer patients treated with non-fermented ME. We included randomized controlled trials (RCTs) and non-randomized studies of intervention (NRSIs). The risk of bias was assessed with Cochrane’s ROB2 and ROBINS-I; a meta-analysis was conducted.

Results:

Eleven RCTs and eight NRSIs met the inclusion criteria. The studies were heterogeneous and their ROB2 and ROBINS-I displayed a moderate and high risk of bias, respectively. For RCTs, the pooled effect estimate of non-fermented ME on survival was HR = 0.81 (95% CI 0.69-0.95, P = .01). Subgroup analyses as well as the NRSIs estimation support the robustness of the finding. When active comparators are added to the analysis, the effect estimates become non-significant.

Conclusion:

The results may indicate a positive impact of non-fermented ME on the overall survival of cancer patients. High quality RCTs are necessary to substantiate our results.

Prospero Registration:

CRD42021233177