Effects of Viscum coloratum (Kom.) Nakai on collagen-induced rheumatoid arthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: Viscum coloratum (Kom.) Nakai has been traditionally used in China for nearly a thousand years to treat rheumatic diseases. However, its efficacy and mechanisms in treating rheumatoid arthritis (RA) have not been demonstrated. AIM OF THE STUDY: To investigate the anti-arthritic effects and molecular mechanisms of Viscum coloratum (Kom.) Nakai on collagen-induced arthritic mice through network pharmacology technology and experimental validation. MATERIALS AND METHODS: First, the main ingredients of the extract of Viscum coloratum (Kom.) Nakai (EVC) were identified through chemical composition characterization using Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS). Then, the collagen-induced arthritis (CIA) model was established in DBA/1 J mice and the ameliorative effects of EVC on the progression of CIA mice were evaluated by oral treatment with different doses of the EVC for 28 days. After that, cytokine antibody microarray assay was used to detect the levels of multiple inflammation-related cytokines and chemokines in each group, and performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) enrichment analysis. Subsequently, the potential target for the effective chemical components of EVC in treating RA was identified using various databases. Additionally, a drug-disease target protein-protein interaction network (PPI) was conducted using Cytoscape for visualization and clustering, while GO and KEGG enrichment analyses were performed with the Metascape database. Finally, identified phenotypes and targets by network pharmacology analysis were experimentally validated in vivo. RESULTS: Treatment with EVC significantly suppressed the severity of CIA with a dramatic reduction of paw swelling, arthritis index, levels of IgGs (IgG, IgG1, IgG2a, and IgG2b), multi-inflammation-related cytokines and chemokines on the progression of CIA. Histopathological examinations showed EVC could markedly inhibit inflammatory cell infiltration, tartrate-resistant acid phosphatase (TRAP) activity of osteoclast, and bone destruction. Furthermore, GO and KEGG enrichment analyses revealed that EVC could ameliorate RA by inhibiting osteoclast differentiation and regulating multiple signaling pathways including Osteoclast differentiation, IL-17, and TNF. PPI network analysis demonstrated that AKT1, MMP9, MAPK3, and other genes were highly related to EVC in treating RA. Finally, we proved that EVC could inhibit the expression of NFTAc1, MMP9, Cathepsin K, and AKT which were closely related to osteoclast activity. CONCLUSIONS: EVC could treat RA through multiple components, multiple targets, and multiple pathways. The present study demonstrated the therapeutic efficacy of EVC and its molecular mechanisms in treating RA, indicating that it would be a potent candidate as a novel botanical drug for further investigation.

Photosynthesis, ionomics and metabolomics of the host-hemiparasite association Acacia gerrardii-Viscum schimperi.

Viscum schimperi is an evergreen hemiparasitic plant that can grow on stems and branches of several tree species. It penetrates the host tissues and forms a vascular bridge (haustorium) to withdraw the nutritive resources. Its relationships with hosts remain unknown. This study aimed to investigate the physiological and biochemical attributes of the host-hemiparasite association Acacia gerrardii -Viscum schimperi . The hemiparasite exhibited 2.4- and 3.0-fold lower photosynthetic activity and water use efficiency, and 1.2- and 4.1-fold higher transpiration rate and stomatal conductance. Equally, it displayed 4.9- and 2.6-fold greater water potential and osmotic potential, and in least 3.0times more accumulated 39 K, 85 Rb and 51 V, compared to the host. Nevertheless, it had no detrimental effect on photosynthetic activity, water status and multi-element accumulations in the host. Based on metabolome profiling, V. schimperi could use xanthurenic acid and propylparaben to acquire potassium from the host, and N -1-naphthylacetamide and N -Boc-hydroxylamine to weaken or kill the distal part of the infected branch and to receive the total xylem contents. In contrast, A. gerrardii could used N -acetylserotonin, arecoline, acetophenone and 6-methoxymellein to defend against V. schimperi infection.

Study on the dynamic variation of the secondary metabolites in Viscum coloratum using targeted metabolomics.

Viscum coloratum (Kom.) Nakai is a well-known medicinal plant. However, the optimal harvest time for V. coloratum is unknown. Few studies were performed to analyze compound variation during storage and to improve post-harvest quality control. Our study aimed to comprehensively evaluate the quality of V. coloratum in different growth stages, and determine the dynamic variation of metabolites. Ultra-performance liquid chromatography tandem mass spectrometry was used to quantify 29 compounds in V. coloratum harvested in six growth periods, and the associated biosynthetic pathways were explored. The accumulation of different types of compounds were analyzed based on their synthesis pathways. Grey relational analysis was used to evaluate the quality of V. coloratum across different months. The compound variation during storage was analyzed by a high-temperature high-humidity accelerated test. The results showed that the quality of V. coloratum was the hightest in March, followed by November, and became the lowest in July. During storage, compounds in downstream steps of the biosynthesis pathway were first degraded to produce the upstream compounds and some low-molecular-weight organic acids, leading to an increase followed by a decrease in the content of some compounds, and resulted in a large gap during the degradation time course among different compounds. Due to the rapid rate and large degree of degradation, five compounds were tentatively designated as "early warning components" for quality control. This report provides reference for better understanding the biosynthesis and degradation of metabolites in V. coloratum and lays a theoretical foundation for rational application of V. coloratum and better quality control of V. coloratum during storage.

Biological activities of Viscum tuberculatum aqueous leaf extract.

CONTENT: Plant-based natural products have served as sources of remedies against pathogenic microorganisms. Although the biological activities of Viscum (Santalaceae) species are widely recognized, there is no scientific evidence for Viscum tuberculatum A. Rich. in Ethiopia. OBJECTIVE: To investigate the antimicrobial, acute toxicity, anti-inflammatory properties and phytochemical constituents of an aqueous extract of V. tuberculatum from Ethiopia. MATERIALS AND METHODS: The antibacterial activity of the aqueous leaf extract of V. tuberculatum was tested against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of this extract were determined using the broth macrodilution method. The acute toxicity and anti-inflammatory effects of the extract were investigated using standard procedures on female and male white albino mice, aged 8 and 10 weeks, respectively. The phytochemical constituents of V. tuberculatum were determined using LC-MS QTOF. RESULTS: The MIC and MBC values against S. aureus were found to be 6.25 and 100 mg/mL. The LD50 value was more than 2000 mg/kg body weight of the mouse. The 400 mg/kg dose exerts 87% inhibition after 5 h of carrageenan injection. Twenty-five different metabolites, mainly flavonoids, phenolic acids and alkaloids, were identified. CONCLUSIONS: These findings demonstrate the potential antimicrobial and anti-inflammatory potential of the aqueous extract of V. tuberculatum.

Study on the dynamic variation of the secondary metabolites in Viscum coloratum using targeted metabolomics / 中国天然药物

Viscum coloratum (Kom.) Nakai is a well-known medicinal plant. However, the optimal harvest time for V. coloratum is unknown. Few studies were performed to analyze compound variation during storage and to improve post-harvest quality control. Our study aimed to comprehensively evaluate the quality of V. coloratum in different growth stages, and determine the dynamic variation of metabolites. Ultra-performance liquid chromatography tandem mass spectrometry was used to quantify 29 compounds in V. coloratum harvested in six growth periods, and the associated biosynthetic pathways were explored. The accumulation of different types of compounds were analyzed based on their synthesis pathways. Grey relational analysis was used to evaluate the quality of V. coloratum across different months. The compound variation during storage was analyzed by a high-temperature high-humidity accelerated test. The results showed that the quality of V. coloratum was the hightest in March, followed by November, and became the lowest in July. During storage, compounds in downstream steps of the biosynthesis pathway were first degraded to produce the upstream compounds and some low-molecular-weight organic acids, leading to an increase followed by a decrease in the content of some compounds, and resulted in a large gap during the degradation time course among different compounds. Due to the rapid rate and large degree of degradation, five compounds were tentatively designated as "early warning components" for quality control. This report provides reference for better understanding the biosynthesis and degradation of metabolites in V. coloratum and lays a theoretical foundation for rational application of V. coloratum and better quality control of V. coloratum during storage.

Diverse chemical modifications of the chlorogenic acid composition of Viscum combreticola Engl.: A premise for the state of readiness against excessive sunlight exposure.

Mistletoe plants that are positioned on the canopy of their hosts are more susceptible to UV radiation exposure. These aerial plants are resistant to damage by UV radiation due the presence of epidermal constituents such as the cuticle, cork layer, trichomes and antioxidant secondary metabolites. In response to the photo-oxidative stress associated with UV exposure, plants generally deploy photo-protective responsive mechanisms that involve the biosynthesis of UV absorbing phenolic compounds such as chlorogenic acids (CGAs). The hydroxycinnamic acid moieties of these CGAs are predominantly in the trans configuration, naturally. However, excessive sunlight exposure of plants containing these compounds can result in geometrical isomerisation, characterized by the formation of cis isomers. Therefore, in this study, the effect of UV light radiation on the CGA composition of Viscum combreticola Engl. (Santalacaeae) plants using an in vitro model was unravelled through UHPLC-q-TOF-MS-based metabolic profiling. Interestingly, the findings of this study revealed that this plant has a diverse chemical composition of CGAs that is characterized by epimerization, monoacylation, homodiacylation and heterodiacylation of the quinic acid (QA), thereby, contributing to the state of readiness in these plants against sunlight or UV exposure. In addition to the commonly reported cinnamoyl containing heterodiacylated CGAs, hydroxybenzoyl containing heterodiacylated CGAs were also reported in this study. Moreover, cis isomers (24 in total) of some CGAs were identified in the non-irradiated samples and the formation of these compounds has been reported to help plants in the mitigation of photo-oxidative stress. An additional 28 cis isomers of CGAs and HCA derivatives were observed in the UV-irradiated samples, hence, further increasing the complexity of the metabolome of this plant, with a total of 108 compounds identified in this study. The presence of epimers, positional and geometrical isomers of these compounds could be a biochemical strategy to maximize the chemical arsenal of this plant to withstand the photo-oxidative stress posed by UV radiation from the sunlight. Due to purported pharmacological properties associated with the identified compounds these parasitic plants can be a rich source of prospective therapeutic compounds that can be employed as drug discovery leads. Moreover, UV radiation might be essential in future to produce potent drugs since plants naturally produce these compounds in low quantities.

LC/MS analysis of Viscum cruciatum Sieber ex Boiss. extract with anti-proliferative activity against MCF-7 cell line via G0/G1 cell cycle arrest: An in-silico and in-vitro study.

ETHNOPHARMACOLOGICAL RELEVANCE: Viscum cruciatum Sieb is a well-known medicinal plant in Jordan containing various secondary metabolites. It has traditionally been used to treat many ailments, most notably cancer. However, there is a significant gap between scientific research and its value in traditional medicine. AIM OF THE WORK: To evaluate the antiproliferative activity of different V. cruciatum extracts against MCF-7 breast cancer cell lines and recognize the affected cell cycle phase. Besides, identifying the bioactive components present in the active extract using LC/MS technique. Also, to determine the possible mechanism of action by in silico and in-vitro study. MATERIALS AND METHODS: V. cruciatum was extracted using solvents with increasing polarity. The antiproliferative effects of the extracts against MCF-7 cell lines were evaluated using SRB assay. Further, flow cytometry was used to identify the inhibited phase of the cell cycle, while LC/MS-MS technique was used to analyze the chemical composition of the most active extract. After that, the putative mechanism of action was investigated through in-silico docking, molecular dynamic simulation for compounds with the highest docking scores, and Western blot analysis of cyclin-dependent kinases (CDK2/4/6). RESULTS: The chloroform/methanol 90/10 (ChMe) extract showed the most potent antiproliferative effect against MCF-7 cells (IC50 = 23.8 µg/mL), and cell cycle arrest at the G0/G1phase. Furthermore, LC-MS/MS analysis revealed the presence of several polyphenolics belonging to the flavonoids and phenolic acids classes. Additionally, quercetin-4'-glucoside, 3, 5, 7-trihydroxy-4'-methoxy flavone, and hesperetin-7-O-neohesperidoside demonstrated the highest docking binding scores and stable complexes against CDK2 and CDK4/6. Moreover, RMSD (root-mean-square deviation), RMSF (root-mean-square fluctuation), Rg (radius of gyration), and energy analysis during molecular dynamic simulation indicated the stable binding of the studied complexes. These results were supported by Western blot analysis, which revealed the downregulation of CDK2, CDK4, and CDK6 protein expression in MCF-7 cell lines. CONCLUSION: These findings emphasized the potential breast anticancer activity of the V. cruciatum ChMe extract by arresting the G0/G1 phase of the cell cycle, which could be related to its flavonoid content. Moreover, the results provided experimental support for the traditional anticancer activity of V. cruciatum, and its ChMe extract might be a source of chemoprotective or chemotherapeutic isolates.

Chemical constituents of Viscum coloratum (Kom.) Nakai and their cytotoxic activities.

A new diarylheptanoid, (1 R,2S,3S,5S)-2,3-dihydroxy-3',3''-dimethoxy-4'-de-O-methylcentrolobine (1) and a new bisabolane-type sesquiterpenoid, (1 R,7S)-1,12,13-trihydroxybisabola-3,10-diene (2), together with nineteen known compounds (3-21) were isolated from the EtOH extract of the stems and branches of Viscum coloratum (Kom.) Nakai. Their structures were elucidated by extensive analysis of 1 D and 2 D NMR spectra and from the HRESIMS. All the compounds were evaluated for their cytotoxic activity against eight human tumor cell lines.

Chemical-activity-based quality marker screening strategy for Viscum articulatum.

Viscum articulatum Burm. f. is a parasitic plant rich in flavonoids, triterpenoids, and catechins and has a high nutritional value. It has been reported that consuming V. articulatum can prevent cardiac diseases. In this study, six bioactive compounds, including catechins, triterpenoids, and phenylpropanoid glycosides, were determined in alcohol extracts of the plant using HPLC. The anti-inflammatory and antioxidant activities of three catechins, two triterpenoids, and three combination drugs were measured in cardiomyocytes, and the results showed that the anti-inflammatory activity was significantly enhanced while retaining strong antioxidant activity when epicatechin and ursolic acid were used in combination. The main quality markers epicatechin and ursolic acid were screened based on the specificity of the genuine herb and a potent synergistic effect, and the lowest limitation contents of V. articulatum which could discriminate it from some other taxonomically similar materials were accordingly determined. This self-built lowest limitation content of the two screened quality markers could quickly and accurately reflect the efficacy in terms of chemical composition and reverse the disorderly market use of nongenuine herbs or confusing species for adulteration. This study is of some significance for market regulation, drug development, and clinical medication.

[Lectins in Viscum:a progress review].

Viscum plants,the evergreen perennial parasitic shrubs or subshrubs,are mainly distributed in tropical and subtropical regions. There are about 70 Viscum species around the world,including 11 species and one variety in China. Mistletoe lectins are typeⅡ ribosome-inactivating proteins( RIPs) extracted from Viscum plants with anticancer and immunoregulatory activities. Many studies have focused on the mistletoe lectins isolated from V. album in Europe and V. album var. coloratum distributed in South Korea,respectively,and several preparations,such as Iscucin Ⓡ,were developed and clinically applied for cancer treatment. Although Viscum plants are widely distributed in China,only a few studies of mistletoe lectins have been reported. The recent progress of mistletoe lectins was reviewed from extraction,purification,quantitative/qualitative detection,molecular structure,pharmacological activities,toxicities,and clinical application,aiming at providing a reference for in-depth research and utilization of mistletoe lectins produced in China.

Korean mistletoe (Viscum album var. coloratum) extends the lifespan via FOXO activation induced by dSir2 in Drosophila melanogaster.

AIM: We examined the underlying mechanisms associated with the longevity effects of Korean mistletoe extract (KME) in Drosophila melanogaster. METHODS: We measured the lifespan of sirtuin, chico and foxo mutant flies fed KME, the expression of the forkhead box O (FOXO) target genes and insulin-like peptide genes, and the localization of FOXO in flies fed the KME. RESULTS: The longevity effect of KME was abolished in sirtuin, chico and foxo null mutant flies. In addition, the expression of FOXO target genes and the localization of FOXO into nuclei were increased in flies fed KME, but the expression of the insulin-like peptide genes was decreased by KME supplementation. CONCLUSIONS: The results show that KME extends the fly lifespan through sirtuin-induced FOXO activation. We suggest that KME has potential use as a beneficial anti-aging and longevity supplement. Geriatr Gerontol Int 2021; 21: 725-731.

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.

Lectins in Viscum:a progress review / 中国中药杂志

Viscum plants,the evergreen perennial parasitic shrubs or subshrubs,are mainly distributed in tropical and subtropical regions. There are about 70 Viscum species around the world,including 11 species and one variety in China. Mistletoe lectins are typeⅡ ribosome-inactivating proteins( RIPs) extracted from Viscum plants with anticancer and immunoregulatory activities. Many studies have focused on the mistletoe lectins isolated from V. album in Europe and V. album var. coloratum distributed in South Korea,respectively,and several preparations,such as Iscucin Ⓡ,were developed and clinically applied for cancer treatment. Although Viscum plants are widely distributed in China,only a few studies of mistletoe lectins have been reported. The recent progress of mistletoe lectins was reviewed from extraction,purification,quantitative/qualitative detection,molecular structure,pharmacological activities,toxicities,and clinical application,aiming at providing a reference for in-depth research and utilization of mistletoe lectins produced in China.

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.

Enzymatic extraction optimization, anti-HBV and antioxidant activities of polysaccharides from Viscum coloratum (Kom.) Nakai.

An enzyme-assisted extraction method had been optimized by single factor experiments and orthogonal test design, to improve the extract yield of polysaccharides from the leaves of Viscum coloratum (Kom.) Nakai (VCP). The anti-HBV activity of VCP in vitro was investigated by PCR-fluorescent probing (FQ-PCR) and ELISA methods. Moreover the antioxidant activity of VCP in vitro was studied in terms of the reducing power, 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) test radical-scavenging activity and hydroxyl radicals-scavenging activity. The results demonstrated that the optimum extraction conditions were solid-liquid ratio of 1:40, enzyme concentrations of 2.5%, enzyme action time of 40 min, enzyme action temperature of 50 °C, enzymatic pH of 5. Under these conditions, the extraction yield of VCP was 21.83 ±â€¯0.45%. VCP could inhibit the replication of HBV-DNA and the secretion of HBV antigens in a dose-dependent manner, and showed better antioxidant capacity. These findings suggest that VCP could be a good potential natural antiviral agent and antioxidant.

Anticolitic Effect of Viscum coloratum through Suppression of Mast Cell Activation.

Viscum coloratum has been used as a component for traditional medicine for therapy of inflammatory diseases. Nonetheless, effect of Viscum coloratum on inflammatory bowel disease is unknown. Therefore, we investigated whether the ethanol extract of Viscum coloratum (VCE) could suppress inflammatory responses in dextran sodium sulfate (DSS)-treated mice and mast cell-derived inflammatory mediator (MDIM)-activated Caco-2 cells. VCE significantly attenuated body weight loss, shortened colon length, enteric epithelium disruption, enterorrhagia and colonic edema in DSS-treated mice. Additionally, VCE decreased the levels of immunoglobulin E, interleukin-6 and tumor necrosis factor- α in serum and the activity of myeloperoxidase in colonic tissue. Moreover, VCE inhibited the infiltration of immune cells as well as the activity and expression of both matrix metalloprotease-2 and matrix metalloprotease-9. Furthermore, VCE restored zonula occludens-1 expression. Consistent with in vivo studies, VCE suppressed the activity and expression of matrix metalloprotease-2 and matrix metalloprotease-9 in MDIM-activated Caco-2 cells. In addition, VCE reinstated the expression of zonula occludens-1 through inhibiting activation of janus kinase 2/signal transducer and activator of transcription 3 in the cells. In conclusion, VCE exerts anticolitic action through inhibiting the activation of mast cells. Therefore, VCE may be useful as a phytomedicine or functional food for inflammatory bowel disease.

Morphology, geographic distribution, and host preferences are poor predictors of phylogenetic relatedness in the mistletoe genus Viscum L.

Besides their alleged therapeutic effects, mistletoes of the genus Viscum L. (Viscaceae) are keystone species in many ecosystems across Europe, Africa, Asia and Australia because of their complex faunal interactions. We here reconstructed the evolutionary history of Viscum based on plastid and nuclear DNA sequence data. We obtained a highly resolved phylogenetic tree with ten well-supported clades, which we used to understand the spatio-temporal evolution of these aerial parasites and evaluate the contribution of reproductive switches and shifts in host ranges to their distribution and diversification. The genus Viscum originated in the early Eocene in Africa and appeared to have diversified mainly through geographic isolation, in several cases apparently coinciding with shifts in host preferences. During its evolution, switches in the reproductive mode from ancestral dioecy to monoecy imply an important role in the long-distance dispersal of the parasites from Africa to continental Asia and Australia. We also observed multiple cases of photosynthetic surface reduction (evolution of scale leaves) within the genus, probably indicative of increasing specialization associated with the parasitic lifestyle. Even compared with other parasitic angiosperms, where more host generalists than specialists exist, Viscum species are characterized by extraordinarily broad host ranges. Specialization on only a few hosts from a single family or order occurs rarely and is restricted mostly to very recently evolved lineages. The latter mostly derive from or are closely related to generalist parasites, implying that niche shifting to a new host represents an at least temporary evolutionary advantage in Viscum.

1,7-Bis(4-hydroxyphenyl)-1,4-heptadien-3-one induces lung cancer cell apoptosis via the PI3K/Akt and ERK1/2 pathways.

1,7-Bis(4-hydroxyphenyl)-1,4-heptadien-3-one (EB30) is a diarylheptanoid-like compound isolated from Viscum coloratum. This curcumin analog exhibits significant cytotoxic activity against HeLa, SGC-7901, and MCF-7 cells. However, little is known about the anticancer effects and mechanisms of EB30 in human lung cancer. The current study reports that EB30 significantly reduced the cell viability of A549 and NCI-H292 human lung cancer cells. Further examination revealed that EB30 not only induced cell cycle arrest and promoted the generation of reactive oxygen species (ROS) but also induced cell apoptosis through the intrinsic and extrinsic signaling pathways. Furthermore, EB30 upregulated the expression levels of p-ERK1/2 and p-P90RSK, whereas downregulating the phosphorylation of Akt and P70RSK. Cell viability was further inhibited by the combination of EB30 with LY294002 (a specific PI3K inhibitor) or U0126 (a MEK inhibitor). The current study indicates that EB30 is a potential anticancer agent that induces cell apoptosis via suppression of the PI3K/Akt pathway and activation of the ERK1/2 pathway.

GADD45A and CDKN1A are involved in apoptosis and cell cycle modulatory effects of viscumTT with further inactivation of the STAT3 pathway.

ViscumTT, a whole mistletoe preparation, has shown synergistic induction of apoptosis in several pediatric tumor entities. High therapeutic potential has previously been observed in Ewing's sarcoma, rhabdomyosarcoma, ALL and AML. In this study, we analyzed modulatory effects on the cell cycle by viscumTT in three osteosarcoma cell lines with various TP53 statuses. ViscumTT treatment induced G1 arrest in TP53 wild-type and null-mutant cells, but S arrest in TP53 mutant cells. Blockage of G1/S transition was accompanied by down-regulation of the key regulators CDK4, CCND1, CDK2, CCNE, CCNA. However, investigations on the transcriptional level revealed secondary TP53 participation. Cell cycle arrest was predominantly mediated by transcriptionally increased expression of GADD45A and CDKN1A and decreased SKP2 levels. Enhanced CDKN1A and GADD45A expression further played a role in viscumTT-induced apoptosis with involvement of stress-induced MAPK8 and inactivation of MAPK1/3. Furthermore, viscumTT inhibited the pro-survival pathway STAT3 by dephosphorylation of the two sites, Tyr705 and Ser727, by down-regulation of total STAT3 and its direct downstream targets BIRC5 and C-MYC. Moreover, tests of the efficacy of viscumTT in vivo showing reduction of tumor volume confirmed the high therapeutic potential as an anti-tumoral agent for osteosarcoma.

Viscum articulatum Burm. f. aqueous extract exerts antiproliferative effect and induces cell cycle arrest and apoptosis in leukemia cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Viscum articulatum Burm. f. (leafless mistletoe) has been used in traditional system of medicines in India, China, Taiwan, Cambodia, Laos, and Vietnam, to treat blood-related diseases and various inflammatory and degenerative diseases including cancer. Anticancer activities of some phytomolecules purified from Viscum articulatum Burm. f. have been tested. However scientific evidence for the anticancerous potential of aqueous extract of V. articularum (VAQE) used in traditional medicine is lacking. AIM OF THE STUDY: To study the antiproliferative and apoptotic effect of VAQE on Jurkat E6.1 and THP1 leukemia cells. MATERIALS AND METHODS: The aqueous extract of the whole plant of Viscum articulatum Burm. f. was prepared in phosphate buffer saline. In VAQE, total soluble protein was estimated using Bradford's dye-binding assay; flavonoid content was determined using aluminum chloride colorimetric assay; and phenolic content was estimated following Folin-Ciocalteu colorimetric assay. XTT cell viability assay was used to test VAQE induced cytotoxicity in Jurkat E6.1 and THP1 leukemia cells and peripheral blood mononuclear cells (PBMC). The effect of VAQE on cell cycle progression was analyzed by PI staining using flow cytometry. Annexin-V-FITC/PI differential staining method was used for detecting the onset of apoptosis in leukemia cells. Rhodamine 123 dye was used to detect the change in mitochondrial membrane potential (MMP) using flow cytometry. DCF-DA fluorescence dye was used to estimate the level of reactive oxygen species (ROS). The ROS inhibitors were used to evaluate the role of ROS in mediating DNA degradation in VAQE-treated leukemia cells. The molecular mechanisms underlying VAQE induced apoptosis induction was studied by analyzing the expression of anti-apoptotic (Bcl-2) and pro-apoptotic (Bax) proteins, caspase-8 and caspase-3 enzymes using western blot. Diphenylamine (DPA) assay was used to determine the DNA fragmentation and conclusion of apoptosis. RESULTS: VAQE triggered cytotoxic effect on Jurkat E6.1 (IC50-2.4 µg/ml; 24 h) and THP1 (IC50-1.0 µg/ml; 24 h) cells in a dose- and time-dependent manner. The apoptosis induction and G2/M arrest of the cell cycle are the cause of VAQE-induced cytotoxicity in leukemia cells. The apoptosis in VAQE-treated Jurkat E6.1 and THP1 cells was mediated via a reduction in MMP, elevation of intracellular ROS, decreased expression of the anti-apoptotic (Bcl-2) and increased expression of the pro-apoptotic (Bax) protein, activation of caspase-8 and caspase-3 and DNA fragmentation. CONCLUSION: VAQE has a high efficacy to exert a cytotoxic effect in Jurkat E6.1 and THP1 cells and to induce apoptosis and G2/M cell cycle arrest. VAQE induces extrinsic pathway of apoptosis in both the leukemia cell lines via disruption of MMP, intracellular ROS imbalance, increased ratio of Bax/Bcl-2, activation of caspase-8, caspase-3 and ROS-mediated DNA fragmentation. The knowledge gained from the outcomes of the study may encourage the identification of novel chemotherapeutic agent from Viscum articulatum Burm. f. to treat leukemia.