Which is the More Effective Option for Pleurodesis to Prevent the Recurrence of Malignant Pleural Effusion? Large-Particle Talc or Mistletoe Extract (ABNOVA Viscum Injection)

Background

Malignant pleural effusion affects many patients with advanced cancer. When chemotherapy or radiotherapy fails to relieve malignant pleural effusion and related symptoms, drainage and pleurodesis can help. Although surgical talc pleurodesis is the most widely used method, Viscum album, which has been recently used in surgical or bedside procedures, has demonstrated significant results and is as effective as talc. This study aimed to determine the most effective agent and procedure.

Methods

Between January 2015 and July 2022, chemical pleurodesis was performed in 137 patients with malignant pleural effusion, using a V. album surgical procedure in 48, a V. album bedside procedure in 55, and a talc surgical procedure in 34 patients. We reviewed patients' clinical responses and disease progression after chemical pleurodesis.

Results

The success rate was not significantly different among the V. album surgical procedures (91.7%), V. album bedside procedures (83.6%), and talc surgical procedures (91.2%). However, the total drainage amount and tube insertion duration in both Viscum groups were more effective than those in the talc group. Furthermore, the bedside Viscum group showed significantly lower post-pleurodesis pain scores than the other 2 groups.

Conclusion

According to our results, talc and V. album can be considered ideal agents for chemical pleurodesis. However, Viscum pleurodesis showed safer outcomes in terms of ensuring quality of life than talc. Additionally, the bedside Viscum group showed significantly lower pain scores than the other groups. Hence, patients for whom surgical procedures are inappropriate can undergo bedside Viscum pleurodesis without diminishing the therapeutic effect.

Traditional Uses, Phytochemical Constituents and Ethnopharmacological Properties of Mistletoe from Phoradendron and Viscum Species

Plants from the genus Phoradendron and Viscum, also known as American and European mistletoe, are a group of hemiparasitic plants traditionally used to treat many diseases. Mistletoes have a rich content of natural compounds like terpenes, alkaloids, proteins, and phenolic compounds associated with their potential medicinal properties. In this sense, mistletoes have shown antiproliferative, antioxidant, anti-inflammatory, and antimicrobial activity, which has been attributed to their phytochemical constituents. The mechanisms in which mistletoe plants act vary and depend on their phytochemical content and distribution, which in part will depend on the mistletoe species. In this sense, recent literature research is needed to visualize state of the art in the ethnopharmacological potential of mistletoe. Thus, this literature review aims to systematically report recent studies (2010-2023) on the phytochemical characterization and bioactive studies of mistletoe plants, mainly the Viscum and Phoradendron genera. We gather recent information of 161 references selected in our research. Here we report that although there are several bioactivity studies of mistletoe species, bioavailability studies are still scarce, and the precise mechanisms of action are not fully known. We encourage that further studies include a systematic strategy to cover these areas of opportunity.

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.

A Scoping Review of Genus Viscum: Biological and Chemical Aspects of Alcoholic Extracts

The genus Viscum comprises a large number of semi-parasitic shrubs popularly known as Mistletoe. The Viscum species grow in many countries of Europe, Africa and Asia with different popular uses in ornamentation, foods and medicine. Many studies about Viscum have been done over the last years focusing on biological activities and chemical composition of the aqueous extracts, mainly related to anthroposophical medicines. However, it is known that non-aqueous preparations, as alcoholic extracts, have demonstrated different biological activities that are species-and host tree-dependent. Considering the potential of these alcoholic extracts, a scoping review was conducted using data from three online databases: PubMed, Scopus and Embase. Inclusion criteria consisted of the in vitro, in vivo, ex vivo, clinical and chemical studies of alcoholic extracts from Viscum species. The present review summarized 124 original publications about fourteen Viscum species. Viscum album, Viscum articulatum and Viscum coloratum were the main studied species. Alcoholic extracts demonstrated hypotensive, anticancer, antimicrobial, analgesic and anti-inflammatory capabilities, among other biological activities. Flavonoids, phenolic acids and terpenoids represented 48%, 24% and 11% of the total identified compounds, respectively. This review contributes to the knowledge of alcoholic preparations of the Viscum species and points out the lack of clinical studies concerning these different extracts.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

homogenizer-assisted and ultrasound-assisted extracts as potential sources of bioactive compounds

Viscum album L. (Mistletoe) is one of the most famous plants in many countries utilized for several purposes. The current study aimed to describe chemical profiles and biological activities of homogenizer-assisted extract (HAE) and ultrasound-assisted extract (UAE)) of V. album parts (leaf, fruits, and seeds). Antioxidant (radical scavenging, reducing power, metal chelation, and phosphomolybdenum assays) and enzyme inhibitory properties (cholinesterases, amylase, glucosidase, and tyrosinase) were selected for biological evaluation. Chemical profiles were studied by HPLC-MS/MS and 32 compounds were identified in the extracts; caffeoylquinic acids and its derivatives, dimethylated flavonoids were the most significant compounds. Generally, the leaf extracts exhibited the best antioxidant and enzyme inhibitory effects in our tests. Multivariate analysis was performed to obtain more information for these data, then strong correlations between total bioactive compounds and tested parameters were observed. The present findings encourage us to further investigate V. album as a potential candidate for pharmaceutical and nutraceutical applications. PRACTICAL APPLICATIONS: Viscum album L. commonly called European mistletoe is a woody perennial shrub growing on coniferous trees with lathery leaves, small flowers, and white berries. It belongs to the Santalaceae R. Br. family from Europe and western/southern Asia. Traditional medicine recognizes mistletoe as a folk remedy to manage inflammation, hypertension, ulcers, and other diseases due to the presence of different bioactive compounds, among them mistletoe lectins and viscotoxins. Recent studies documented the possible therapeutic applications of Viscum extracts in association with cancer's therapy leading to improvements in health and patient's quality of life. Thus, this work gives novel data regarding the phytochemical characterizations and antioxidant/enzymatic inhibitor activities of different types of extracts from seeds, leaves, and fruits of Viscum L. obtained by homogenizer-assisted and ultrasound-assisted techniques, in order to increase the data set of potential applications in medicine.

Biological activity of mistletoe: in vitro and in vivo studies and mechanisms of action

Mistletoe has been used as treatment of many diseases in traditional and folk medicine. To date, anticancer, immunomodulatory, cardiac, antidiabetic, hepatoprotective, neuropharmacological, antibacterial and antifungal properties of mistletoe extracts have been studied the most. In this review, we summarized in vitro and in vivo studies on the pharmacological activity of Viscum species. Furthermore, we proposed the possible mechanisms of action of this herb, which might include many signalling pathways. Mistletoe could regulate either similar or different targets in various pathways that act on membrane receptors, enzymes, ion channels, transporter proteins and transcriptional targets. Still, pharmacological activities of mistletoe have been investigated mainly for crude extracts. It is a new field for scientists to determined which chemical compounds are responsible for the individual biological activities of mistletoe and how these activities are achieved. As a result, mistletoe might become a source of new complementary therapies supporting the treatment of many diseases.

Oleanolic Acid Prevents Increase in Blood Pressure and Nephrotoxicity in Nitric Oxide Dependent Type of Hypertension in Rats

Background:

Recently, we have reported antihypertensive activity of oleanolic acid (OA) in glucocorticoid-induced hypertension with restoration of nitric oxide (NO) level. However, the involvement of NO-releasing action of OA was unclear.

Objective:

To explore antihypertensive activity of OA in N^ω-nitro-L-arginine methyl ester (L-NAME) hypertensive rats wherein NO is completely blocked, which would allow exploring the possibility of involvement of NO-releasing action of OA.

Materials and Methods:

Five groups of rats were investigated as normal control, L-NAME (40 mg/kg/day), L-NAME + enalapril (15 mg/kg/day), L-NAME + l-arginine (100 mg/kg/day), and L-NAME + OA (60 mg/kg/day) for 4 weeks. The systolic blood pressure, body weight, and heart rate were measured weekly for 4 weeks. Serum nitrate/nitrite (NOx) level, urine electrolytes concentration, cardiac mass index, and serum creatinine level were determined followed by organ histopathology.

Results:

OA and enalapril delayed the rise in blood pleasure following L-NAME administration. Decreased serum NOx level was not significantly increased with any of the treatment. OA produced a small, though nonsignificant, increase in the NOx level. L-NAME administration did not affect cardiac mass index. There was an increase in serum creatinine upon L-NAME administration which was prevented by OA. Decreased urine volume, urine sodium and potassium were reversed by OA.

Conclusion:

These results suggest that the antihypertensive effect of OA in L-NAME hypertension is due to diuresis and nephroprotection. However, OA has nonsignificantly affected the NO levels.

Plastome Evolution in Hemiparasitic Mistletoes

Santalales is an order of plants consisting almost entirely of parasites. Some, such as Osyris, are facultative root parasites whereas others, such as Viscum, are obligate stem parasitic mistletoes. Here, we report the complete plastome sequences of one species of Osyris and three species of Viscum, and we investigate the evolutionary aspects of structural changes and changes in gene content in relation to parasitism. Compared with typical angiosperms plastomes, the four Santalales plastomes are all reduced in size (10–22% compared with Vitis), and they have experienced rearrangements, mostly but not exclusively in the border areas of the inverted repeats. Additionally, a number of protein-coding genes (matK, infA, ccsA, rpl33, and all 11 ndh genes) as well as two transfer RNA genes (trnG-UCC and trnV-UAC) have been pseudogenized or completely lost. Most of the remaining plastid genes have a significantly changed selection pattern compared with other dicots, and the relaxed selection of photosynthesis genes is noteworthy. Although gene loss obviously reduces plastome size, intergenic regions were also shortened. As plastome modifications are generally most prominent in Viscum, they are most likely correlated with the increased nutritional dependence on the host compared with Osyris.