Apoptotic and Cell Cycle Effects of Triterpenes Isolated from Phoradendron wattii on Leukemia Cell Lines.

Current antineoplastic agents present multiple disadvantages, driving an ongoing search for new and better compounds. Four lupane-type triterpenes, 3α,24-dihydroxylup-20(29)-en-28-oic acid (1), 3α,23-dihydroxy-30-oxo-lup-20(29)-en-28-oic acid (2), 3α,23-O-isopropylidenyl-3α,23-dihydroxylup-20(29)-en-28-oic acid (3), and 3α,23-dihydroxylup-20(29)-en-28-oic acid (4), previously isolated from Phoradendron wattii, were evaluated on two cell lines of chronic (K562) and acute (HL60) myeloid leukemia. Compounds 1, 2, and 4 decreased cell viability and inhibit proliferation, mainly in K562, and exhibited an apoptotic effect from 24 h of treatment. Of particular interest is compound 2, which caused arrest in active phases (G2/M) of the cell cycle, as shown by in silico study of the CDK1/Cyclin B/Csk2 complex by molecular docking. This compound [3α,23-dihydroxy-30-oxo-lup-20(29)-en-28-oic acid] s a promising candidate for incorporation into cancer treatments and deserves further study.

Season affects active metabolite composition and cytotoxic effect in Phoradendron wattii methanol extracts.

Plant-derived secondary metabolites are a source of promising bioactive molecules in the search for safer more selective cancer drugs. Mexico's flora is extremely diverse and many species, such as Phoradendron wattii, form part of traditional medicine. Compounds with notable cytotoxic activity have been isolated from P. wattii, but their concentrations may vary seasonally. The aim was to identify any variation in active metabolite concentrations in Phoradendron wattii methanol extracts in response to season. Betulin exhibited the most evident seasonal variations, being most abundant during the midsummer drought. Cytotoxic activity was highest (29 ± 1 µg/mL) in the rainy season methanol extract. Though not the most abundant metabolite in the extracts, 3α,24-dihydroxylup-20(29)-en-28-oic acid is apparently one of the most active among them and is a promising chemotaxonomic biomarker for this species. In summary, secondary metabolite concentrations in P. wattii methanol extracts varied in response to season, and these variations influenced cytotoxic activity.

Does Phoradendron perrottetii (mistletoe) alter polyphenols levels of Tapirira guianensis (host plant)?

The present study aimed to investigate the reciprocal effects of Phoradendron perrottetii (mistletoe) and T. guianensis (host plant) regarding their polyphenol composition. Taking into account that tannins are important molecules in plant defense and their biosynthesis tends to be enhanced when a species is exposed to stress, we address the following questions: (1) Are the tannins found in our model species important in the interaction between host and mistletoe? (2) Does the presence of mistletoe induce changes in the content of tannins and other polyphenols in the host plant? (3) Do we find differences between the tannin sub-groups in the responses of the host plant to mistletoe? (4) Could the observed differences reflect the relative importance of one tannin group over another as chemical defense against the mistletoe? Using a polyphenol and tannin group-specific MRM methods we quantified four different tannin sub-groups together with flavonoid and quinic acid derivatives by ultra-performance liquid chromatography tandem mass spectrometry together with the oxidative and protein precipitation activities of leaves and branches of Tapirira guianensis and Phoradendron perrottetii. We selected leaves and branches of six non-parasitized trees of T. guianensis. Leaves and branches of nine individuals of T. guianensis parasitized by P. perrottetii were also sampled. For each parasitized tree, we sampled an infested branch and its leaves, as well as a non-infested branch and its leaves. Infested branches were divided into three groups: gall (the host-parasite interface), proximal, and distal region. Both proanthocyanidins and ellagitanins seem to be important for plant-plant parasitism interaction: host infested tissues (gall and surrounding regions) have clearly less tannin contents than healthy tissues. Mistletoe showed high levels of quinic acid derivatives and flavonoids that could be important during hastorium formation and intrusion on host tissues, suggesting a defense mechanism that could promote oxidative stress together with an inhibition of mistletoe seed germination, consequently avoiding secondary infestations. Polyphenol detected in T. guianensis-P. perrottetii interaction could play different role as plant-mistletoe strategies of survival.

Lupane-Type Triterpenes of Phoradendron vernicosum.

Three new lupane-type triterpenes, 3α,24-dihydroxylup-20(29)-en-28-oic acid (1), 3α,23-dihydroxy-30-oxolup-20(29)-en-28-oic acid (2), and 3α,23-O-isopropylidenyl-3α,23-dihydroxylup-20(29)-en-28-oic acid (3), together with eight known compounds (4-11) were isolated from a methanol extract of Phoradendron vernicosum aerial parts. The chemical structures of 1-3 were determined on the basis of spectroscopic data interpretation. The isolated compounds were tested against seven human cancer cell lines and two normal cell lines.

Use of GC/MS to identify chemical constituents and cytotoxic activity of the leaves of Phoradendron mucronatum and Phoradendron microphyllum (Viscaceae).

Phoradendron mucronatum and P. microphyllum are plants that found in tropical and subtropical areas, used in traditional medicine and popularly known as mistle-thrush. The aim of this study was to identify the chemical constituents of different leaf extracts from P. mucronatum and P. microphyllum and assess cytotoxic activity against strains from a human tumour cells. Extracts obtained with hexane, dichloromethane, chloroform and ethyl acetate from the leaves were analysed by gas chromatography coupled with mass spectrometry (GC-MS) and the cytotoxicity was assessed by the MTT method (bromide (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)). The tested human tumour cells were NCI-H292 (human pulmonar mucoepidermoid carcinoma), MCF-7 (human breast adenocarcinoma) and HEp-2 (epidermoid carcinoma of the larynx). Analysis by GC/MS of the extracts from leaves of P. microphyllum and P. mucronatum detected 51 different compounds, such as alkaloids, diterpenes, triterpenes, sterols, alcohols, aldehydes, fatty acids and hydrocarbons. In the cytotoxic evaluation, hexane and ethyl acetate extracts from the leaves P. microphyllum inhibited cell growth of NCI-H292 strains (72.97%) and HEp-2 (87.53%), respectively. The extracts of P. mucronatum species showed an inhibitory effect towards NCI-H292 (83.19%/hexane), MCF-7 (88.69%/dichloromethane) and HEp-2 (93.40%/hexane). The extracts showed cytotoxic activity against the tested strains, especially the P. mucronatum, which presented the highest percentages of inhibition of cell growth.

Use of GC/MS to identify chemical constituents and cytotoxic activity of the leaves of Phoradendron mucronatum and Phoradendron microphyllum (Viscaceae)

ABSTRACT Phoradendron mucronatum and P. microphyllum are plants that found in tropical and subtropical areas, used in traditional medicine and popularly known as mistle-thrush. The aim of this study was to identify the chemical constituents of different leaf extracts from P. mucronatum and P. microphyllum and assess cytotoxic activity against strains from a human tumour cells. Extracts obtained with hexane, dichloromethane, chloroform and ethyl acetate from the leaves were analysed by gas chromatography coupled with mass spectrometry (GC-MS) and the cytotoxicity was assessed by the MTT method (bromide (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)). The tested human tumour cells were NCI-H292 (human pulmonar mucoepidermoid carcinoma), MCF-7 (human breast adenocarcinoma) and HEp-2 (epidermoid carcinoma of the larynx). Analysis by GC/MS of the extracts from leaves of P. microphyllum and P. mucronatum detected 51 different compounds, such as alkaloids, diterpenes, triterpenes, sterols, alcohols, aldehydes, fatty acids and hydrocarbons. In the cytotoxic evaluation, hexane and ethyl acetate extracts from the leaves P. microphyllum inhibited cell growth of NCI-H292 strains (72.97%) and HEp-2 (87.53%), respectively. The extracts of P. mucronatum species showed an inhibitory effect towards NCI-H292 (83.19%/hexane), MCF-7 (88.69%/dichloromethane) and HEp-2 (93.40%/hexane). The extracts showed cytotoxic activity against the tested strains, especially the P. mucronatum, which presented the highest percentages of inhibition of cell growth.

Alteraciones anatómicas en epidermis de hojas infectadas de Phoradendron bathyoryctum Eichler (Viscaceae) / Anatomical alterations in epidermis of infected leaves of Phoradendron bathyoryctum Eichler (Viscaceae)

Phoradendron bathyoryctum Eichler (Viscaceae) es una planta hemiparásita que crece en la República Argentina sobre varias especies arbóreas. Se utiliza en medicina popular de la misma manera que el muérdago europeo (Viscum album L. ­Viscaceae­), para disminuir la presión arterial. Los muérdagos, a veces, pueden ser susceptibles de epiparasitismo, o también sufrir el ataque de diferentes agentes fitopatógenos. El objetivo de este estudio es analizar los cambios anatómicos que se producen en las hojas de Ph. bathyoryctum cuando son afectadas por algún agente infeccioso. Se colectaron ejemplares sanos e infectados, los últimos, con lesiones foliares superficiales. Se realizaron técnicas de raspado, diafanizado y obtención de epidermis en las hojas de los ejemplares. También se practicaron reacciones histoquímicas. En las hojas infectadas se observó una destrucción progresiva de los estomas y cambios en el resto de los tejidos epidérmico y subepidérmico, que dieron como resultado la formación de estructuras visibles macroscópicamente, y semejantes a lenticelas foliares. De acuerdo con las observaciones realizadas y por comparación con la bibliografía consultada, se supone que el daño foliar se inicia en el estoma donde se producen cambios estructurales hasta su destrucción, la modificación de las células adyacentes y la formación de lesiones superficiales en las hojas infectadas. En cuanto al agente, si bien no se pudo determinar en esta oportunidad, podría asociarse a algún tipo de virus. Se sugiere realizar futuros estudios para confirmar si los virus son los causantes de las lesiones. (AU)

Morfoanatomia foliar de phoradendron obtusissimum(miq ) eichler (viscaceae), "ka'a votyre'y", utilizado con fines medicinales en una comunidad de Colonia Independencia, Paraguay / Leaf morphoanatomy of Phoradendron obtusissimum(Miq) Eichler (V iscaceae), "ka'avotyre'y", used for medicinal purposes in a community of Colonia Independencia, Paraguay

Resumen: El "ka'avotyre'y", Phoradendron obtusissimum (V iscaceae), es una especie empleada con fines medicinales en Paraguay para tratar enfermedades hepáticas. El presente trabajo se desarrolló dentro del marco del proyecto "Conservación, fortalecimiento y uso sostenible de la flora de Itá Azul y San Gervasio, Colonia Independencia, Reserva de Recursos Manejados Ybytyruzu, Paraguay" y tuvo por objetivo describir la morfoanatomía de P . obtusissimum. Los caracteres diferenciales son: estomas paracíticos en ambas epidermis, índice estomático en epidermis adaxial (5,71)-6,62-(8,33) y en epidermis abaxial (6,45)-1 1,20-(14,29); presencia de drusas en todo el mesófilo. Se presentan así elementos de diagnóstico útiles a la hora de identificar a la especie estudiada. Palabras clave: Phoradendron obtusissimum, morfoanatomía, planta medicinal.

In vitro antioxidant and antiproliferative activities of plants of the ethnopharmacopeia from northwest of Mexico.

BACKGROUND: The aim of this study, is to investigate the in vitro antioxidant activity, the total phenols content, the flavonoids content and the antiproliferative activity of methanolic extracts of the plants: Krameria erecta, Struthanthus palmeri, Phoradendron californicum, Senna covesii and Stegnosperma halimifolium, used by different ethnic groups from northwestern Mexico in the treatment and cure of various diseases. METHODS: The in vitro antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing/Antioxidant Power assay (FRAP), the total phenols content was measured by Folin-Ciocalteau assay, the flavonoids content by the AlCl(3) colorimetric method and the antiproliferative activity (line cells HeLa, RAW 264.7, M12A(k).C3.F6 and L929) using MTT method. RESULTS: The K. erecta extract showed the higher radical scavenging activity (67.88%), antioxidant activity by FRAP (1.41 mg Trolox Eq), the highest total phenols content (598.51 mg Galic Acid Eq/g extract), the highest flavonoids content (3.80 mg Quercetin Eq/g extract) and the greatest antiproliferative activity in a dose dependent manner against most Cell line evaluated. A positive correlation was found between the antioxidant activity and the flavonoids content. CONCLUSIONS: This study is the first report on the antioxidant and antiproliferative activities of the five species evaluated. The results demostrate that there is a positive correlation between antioxidant activity and the flavonoids content, indicating that these type of polyphenols could be the major contributors to the observed antioxidant activity in the evaluated plant extracts. Of the extracts evaluated, that of Krameria erecta showed the greatest antioxidant and antiproliferative activities, a discovery that makes this species a promising candidate for future research.

The antitumoral effect of the American mistletoe Phoradendron serotinum (Raf.) M.C. Johnst. (Viscaceae) is associated with the release of immunity-related cytokines.

ETHNOPHARMACOLOGICAL RELEVANCE: Phoradendron serotinum is commonly used in Mexican traditional medicine for the empirical treatment of cancer. However, there are no studies regarding the antitumoral or immunomodulatory activities of Phoradendron serotinum. MATERIALS AND METHODS: The in vivo toxicity of ethanolic extracts of Phoradendron serotinum (PSE) was evaluated in mice according to the Lorke procedure. The in vitro immunomodulatory effects of PSE were evaluated estimating the effects of PSE on the pinocytosis, NO production and lysosomal enzyme activity in murine macrophages RAW 264.7. The effects of PSE on the proliferation of murine splenocytes and NK cell activity were also assayed. The cytotoxic effects on TC-1 (lung murine cancer cells) were evaluated using the MTT assay, whereas the apoptotic effect of PSE on TC-1 cells was evaluated using TUNEL assay. Also, different doses of PSE were injected intraperitoneally daily into C57BL/6 mice bearing tumors of TC-1 cells during 25 days. The growth and weight of tumors was measured. In addition, the levels of IL-2, IL-6, IL-12, IL-23 and IFN-γ in murine serum and supernatants of K562 cell-murine splenocyte cocultures were measured. RESULTS: PSE stimulated the proliferation, pinocytosis and lysosomal enzyme activity in murine macrophages with a similar potency than lypopolisaccharides 1 µg/ml. In addition, PSE stimulated the proliferation of murine splenocytes and induced the NK cell activity. PSE showed cytotoxic (IC(50)=1.9 µg/ml) and apoptotic effects against TC-1 cells. The LD(50) was 125 mg/kg by intraperitoneal route (i.p.) and 375 mg/kg by oral route. PSE administrated at 1, 5 and 10 mg/kg i.p. inhibited the tumor growth by 18%, 40% and 69%, respectively, in mice bearing TC-1 tumor. PSE increased the in vitro and in vivo release of IL-2, IL-6 and IFN-γ but lacked effect on IL-12 and IL-23 release. CONCLUSIONS: Phoradendron serotinum shows moderate toxic effects in vivo, exerts cytotoxic and apoptotic effects on TC-1 cells. Phoradendron serotinum also has antitumor effects in mice bearing TC-1 tumor and induces immunomodulatory activities in vivo. The results suggest that antitumoral effects of PSE are related with the production of immunity-related cytokines.

Avaliação dos efeitos miorelaxante, antiespasmódico e antinociceptivo do extrato aquoso da Phoradendron piperoides (Kunt.) Trel. (Viscaceae) / Investigation on miorelaxant, antispasmodic and analgesic effects of the aqueous extract of Phoradendron piperoides

Foram investigados os efeitos miorelaxante, antiespasmódico e antinociceptivo do extrato aquoso liofilizado das folhas da Phoradendron piperoides. A toxicidade aguda também foi avaliada. No íleo isolado de cobaio, o extrato aquoso da P. piperoides (0,05 - 2,0 mg/mL) produziu relaxamento de forma concentração-dependente (IC50 = 0,114 mg/mL) e, na concentração de 1,5 mg/mL, reduziu a amplitude das contrações induzidas por carbacol (2 μM), histamina (2 μM) e BaCl2 (0,03 M) em 46,6; 38,6 e 55,3 por cento (p < 0,001), respectivamente. Em camundongos, o extrato aquoso liofilizado (100-400 mg/kg) não reduziu de forma significativa as contorções abdominais induzidas por ácido acético, não modificou o tempo de reação dos animais no teste da formalina e não aumentou o tempo de latência ao calor no teste da placa quente. No ensaio de toxicidade aguda utilizado, não foi detectada a morte de nenhum animal após tratamento com doses de até 5 g/kg (p.o.) do extrato. Em conclusão, os resultados obtidos indicam que o extrato aquoso da P. piperoides apresenta efeito antiespasmódico e baixa toxicidade aguda. O extrato, no entanto, não possui efeito antinociceptivo.

The present work evaluated the antinociceptive, miorelaxant and antispasmodic effects as well as the acute toxicity of the aqueous extract from leaves of Phoradendron piperoides. In guinea pig ileum, the plant extract (0.05 - 2.0 mg/kg) decreased the preparations basal tone in a dose-dependent manner (IC50 = 0.114 mg/mL) and it (1.5 mg/mL) reduced (p < 0.001) the contractions induced by carbachol (2 μM), histamine (2 μM) and BaCl2 (0.03M). The extract, at oral doses of 100, 200, and 400 mg/kg, did not manifest a significant antinociceptive effect in the writhing, formalin and hot-plate tests. Moreover, no animal deaths were observed in doses up to 5 g/kg. In conclusion, the aqueous extract of Phoradendron piperoides showed no antinociceptive effect and no acute toxicity in mice. Indeed, it revealed miorelaxant and antispasmodic activities that are probably miogenic and not specific for neurotransmitters.

Patients are talking about ... Iscador (mistletoe).

Mistletoe generally is categorized as American mistletoe or European mistletoe. Despite its well-known potential for toxicity, mistletoe continues to be used as an herbal remedy and recently has received a great deal of media attention. The U.S. Food and Drug Administration classified mistletoe as a food additive that cannot be marketed unless proven safe for consumption (DerMarderosian, 1992). Several components of the plant have been found to possess antineoplastic activity and warrant further investigation for their clinical potential. At this time, however, mistletoe as a single-agent therapy has not been scientifically validated in the treatment of breast cancer.