Genetic diversity and verbascoside content in natural populations of Pyrostegia venusta (Ker Gawl.) Miers.

BACKGROUND: Pyrostegia venusta (Ker Gawl.) Miers occurs in threatened biodiversity hotspots of Cerrado and Atlantic forest biomes in Brazil and is used in traditional medicine to treat various respiratory and skin diseases. METHODS AND RESULTS: This study (i) examined the genetic diversity and structure of six natural populations of P. venusta from different Brazilian regions using sequence-related amplified polymorphism (SRAP) markers; and (ii) compared the intra- and inter-populational levels of the bioactive component verbascoside using high-performance liquid chromatography. The population from Nova Mutum, Mato Grosso, presented the highest genetic variability (Nei index H = 0.2759; Shannon index I = 0.4170; 85.14% polymorphic loci), whereas the population from Araxá, Minas Gerais, presented the lowest genetic variability (H = 0.1811; I = 0.2820; 70.27% polymorphic loci). The intra-populational variability (79%) was significantly higher (p = 0.001) than the inter-populational variability (21%). The populations were clustered into two groups but their genetic differentiation was not associated with geographical origin (Mantel test, r = 0.328; p > 0.05). The verbascoside content significantly differed (p > 0.05) among the six populations and between the individuals from each population. The highest verbascoside levels (> 200 µg/mg extract) were detected in populations from Araxá and Serrana, while the lowest verbacoside levels were detected in populations from Paranaíta and Sinop. CONCLUSIONS: This is the first report on the use of SRAP markers to analyze genetic variability in the family Bignoniaceae. Our findings shall help to better understand the genetic and chemical diversity of P. venusta populations, as well as provide useful information to select the most appropriate individuals to prepare phytomedicines.

Florivory and Pollination Intersection: Changes in Floral Trait Expression Do Not Discourage Hummingbird Pollination.

Many flowers are fed on by florivores, but we know little about if and how feeding on flowers affects their visual and chemical advertisement and nectar resource, which could disrupt pollination. Here, we investigated if damages caused by florivores compromise a Neotropical hummingbird pollination system, by modifying the floral advertisements and the nectar resource. We surveyed natural florivory levels and patterns, examined short-term local effects of floral damages caused by the most common florivore, a caterpillar, on floral outline, intra-floral colour pattern and floral scent, as well as on the amount of nectar. Following, we experimentally tested if the most severe florivory pattern affected hummingbird pollination. The feeding activity of the most common florivore did not alter the intra-floral colour pattern, floral scent, and nectar volume, but changed the corolla outline. However, this change did not affect hummingbird pollination. Despite visual floral cues being important for foraging in hummingbirds, our results emphasise that changes in the corolla outline had a neutral effect on pollination, allowing the maintenance of florivore-plant-pollinator systems without detriment to any partner.

Improved antimutagenic effect of Pyrostegia venusta (Ker Gawl. ) Miers nanostructured extract in liposome and polymeric nanoparticle

Abstract Pyrostegia venusta (Ker Gawl.) Miers, popularly known as "Cipó-de São-João", has been used in traditional medicine for its therapeutic properties. Nanotechnology is able to enhance the pharmacological activity of plant extracts. In this context, liposomes and polymeric nanoparticles containing P. venusta ethanolic extract were developed and then physico-chemically characterized to evaluate the mutagenic/antimutagenic effects of P. venusta. In addition, transaminases and serum creatinine were biochemically analyzed for liver and renal damage, respectively. The micronucleus test was performed with male Swiss mice treated orally for 15 consecutive days with free extracts and nanostructured with P. venusta, and then intraperitoneally with N-ethyl-N-nitrosurea (50 mg/kg) on the 15th day of treatment. Micronucleated polychromatic erythrocytes (MNPCE) were evaluated in bone marrow. There was a significant reduction in the frequency of MNPCE (LPEPV = 183% and NPEPV = 114%, p < 0.001), indicating antimutagenic potential of the nanostructured extracts with P. venusta. The groups treated with only nanostructured extract did not show an increase in MNPCE frequency, and biochemical analyzes showed no significant difference between treatments. The liposomes and polymeric nanoparticles containing Pyrostegia venusta ethanolic extract showed biological potential in preventing the first step of carcinogenesis under the experimental conditions

Pre-clinical evidences of Pyrostegia venusta in the treatment of vitiligo.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves of Pyrostegia venusta are popularly used to treat vitiligo; however, none in vivo study showed its ability. AIM OF THE STUDY: The overall objective of the present study was to evaluate the antiinflammatory and hyperpigmentant activities of hydroethanolic (HE) extract of leaves from P. venusta in animal models of vitiligo induced by croton oil and monobenzone. MATERIALS AND METHODS: The antiinflamatory and antioxidative effects of topical and oral administration of HE extract of P. venusta were evaluated in Swiss mice on edema model induced by croton oil, and further the N-acetyl-b-d-glucosaminidase (NAG) activity, cell infiltration, and cytokine and reactive species oxygen (ROS) levels. The involvement on mice pigmentation, cell infiltration and cytokine levels were evaluated on vitiligo model induced by monobenzone in C56BL/6 mice. RESULTS: HE of P. venusta by gavage (300 mg/kg) reduced NAG activity in 32.5 ± 5% on mouse ear edema induced by croton oil. Similarly, cell infiltration was lower (42.3 ± 5.9%) when compared to control group, as well as interleukin-1ß (IL-1ß), interleukin (IL-6) and tumor necrosis factor-α (TNF-α) levels, in 44.1 ± 9.7%, 71.9 ± 22.2% and to basal levels, respectively. Topical treatment with HE of P. venusta (10%) diminished cell infiltration (67.7 ± 7.1%) and ROS levels (total reduction). P. venusta either by gavage (300 mg/Kg) or topically (10%) increased epidermal melanin level (116.5 ± 13% and 100 ± 16.9%, respectively), diminished dermal depigmentation (36.0 ± 6.7% and 38.2 ± 6.2%, respectively), as well as tissue TNF-α levels (68.2 ± 11.6% and 99.2 ± 12.1%, respectively) and cell infiltration (basal levels and 94.3 ± 9.17%, respectively). However, only topical treatment with HE of P. venusta altered melanin specific marker in hair follicles. CONCLUSIONS: For the first time these data show that topical and oral administrations of P. venusta have significant antiinflammatory and hyperpigmentant effects, demonstrating different topical and systemic effects through two animal models. Together these models are capable to mimic several features founded in vitiligo, and the results support the ethnopharmacological use of P. venusta.

Pyrostegia venusta heptane extract containing saturated aliphatic hydrocarbons induces apoptosis on B16F10-Nex2 melanoma cells and displays antitumor activity in vivo.

BACKGROUND: Pyrostegia venusta (Ker. Gawl.) Miers (Bignoniacea) is a medicinal plant from the Brazilian Cerrado used to treat leucoderma and common diseases of the respiratory system. OBJECTIVE: To investigate the antitumor activity of P.venusta extracts against melanoma. MATERIALS AND METHODS: The cytotoxic activity and tumor induced cell death of heptane extract (HE) from P. venusta flowers was evaluated against murine melanoma B16F10-Nex2 cells in vitro and in a syngeneic model in vivo. RESULTS: We found that HE induced apoptosis in melanoma cells by disruption of the mitochondrial membrane potential, induction of reactive oxygen species and late apoptosis evidenced by plasma membrane blebbing, cell shrinkage, chromatin condensation and DNA fragmentation, exposure of phosphatidylserine on the cell surface and activation of caspase-2,-3,-8,-9. HE was also protective against singeneyc subcutaneous melanoma HE compounds were also able to induce cell cycle arrest at G2/M phases on tumor cells. On fractionation of HE in silica gel we isolated a cytotoxic fraction that contained a mixture of saturated hydrocarbons identified by (1)H NMR and GC-MS analyses. Predominant species were octacosane (C28H58-36%) and triacontane (C30H62-13%), which individually showed significant cytotoxic activity against murine melanoma B16F10-Nex2 cells in vitro and a very promising antitumor protection against subcutaneous melanoma in vivo. CONCLUSION: The results suggest that the components of the heptane extract, mainly octasane and triacontane, which showed antitumor properties in experimental melanoma upon regional administration, might also be therapeutic in human cancer, such as in the mostly epidermal and slowly invasive melanomas, such as acral lentiginous melanoma, as an adjuvant treatment to surgical excision.

Hydroethanolic extract of Pyrostegia venusta (Ker Gawl.) Miers flowers improves inflammatory and metabolic dysfunction induced by high-refined carbohydrate diet.

ETHNOPHARMACOLOGICAL RELEVANCE: Pyrostegia venusta is used in traditional Brazilian medicine as a general tonic to treat any inflammatory disease. Several studies have demonstrated that medicinal plants constitute a therapeutic approach for the treatment of obesity-related metabolic and inflammatory disarrangement. Accordingly, we investigated the effects of hydroethanolic extract of Pyrostegia venusta flowers (PvHE) supplementation for the treatment of inflammatory and metabolic dysfunction induced by high-refined-carbohydrate (HC) diet. MATERIAL AND METHODS: The BALB/c mice were fed chow or HC diet for 8 weeks. Part of these animals was fed with HC diet supplemented with PvHE on the 9th week until the 12th week. At the end of the dietary intervention, animals were sacrificed. RESULTS: We observed that PvHE decreased adiposity and adipocyte area; improved glucose intolerance; reduced serum triacylglycerol levels and systemic inflammatory cells; and also reduced some inflammatory mediators levels in adipose tissue and liver. CONCLUSION: The results showed that PvHE has beneficial effects and may treat inflammatory and metabolic dysfunction induced by HC diet, that are associated to a negative modulation of the inflammatory process at systemic and local levels.

Anti-inflammatory and antinociceptive effects of the hydroethanolic extract of the flowers of Pyrostegia venusta in mice

Pyrostegia venusta (Ker Gawl.) Miers, Bignoniaceae, is native to the Brazilian Cerrado and popularly known as "cipó-de-são-joão". In Brazilian folk medicine, the flowers of P. venusta are used as a general tonic and a treatment for diarrhea, vitiligo, cough, and common infections and inflammatory diseases of the respiratory system. Nevertheless, there are still no studies on its possible anti-inflammatory and antinociceptive effects. The P. venusta hydroethanolic extract (PvHE) was used to evaluate the anti-inflammatory and analgesic effects in carrageenan-induced paw edema, peritonitis induced by lipopolysaccharide, acetic acid-induced writhing, and formalin-induced paw-licking tests in Swiss male mice. PvHE at doses of 30-300 mg/kg p.o. demonstrated anti-inflammatory effect. PvHE reduced paw edema induced by carrageenan and inhibited leukocyte recruitment into the peritoneal cavity. The extracts showed antinociceptive activity in acetic acid-induced writhing and formalin tests. Our results showed that the PvHE demonstrated anti-inflammatory and antinociceptive action in mice. All the anti-inflammatory actions obtained are also suggested to due the presence of acacetin-7-O-β-glucopyranoside.

Efeito do extrato hidroalcoólico de Pyrostegia venusta na mutagênese "in vivo", e avaliação antimicrobiana, e interferência no crescimento e diferenciação celular "in vitro" / Effect of the hydroalcoholic extract of Pyrostegia venusta on "in vivo" mutagenesis and antimicrobial evaluation and interference on the "in vitro" cellular growth and differentiation

Analisa-se a atividade antibacteriana e antifúngica, o crescimento, a diferenciação celular e a ação mutagênica do extrato hidroalcoólico de Pyrostegia venusta (cipó- de-são-joão) em Herpetomonas samuelpessoai. As atividades antimicrobianas foram analisadas por intermédio de métodos de difusão em ágar e macrodiluição. O crescimento e a diferenciação celular de H. samuelpessoai foram realizados em meio quimicamente definido a 28ºC/48 h e analisados quantitativa (câmara de Neubauer) e qualitativamente (formas pró/para/opistomastigota) após coração panótica. A avaliação mutagênica foi realizada pelo teste do micronúcleo em eritroblastos de camundongos Swiss albinus após tratamentos via gavagem (1.000-2.000mg/kg) e decorridos os tempos de 24-48 h. Os resultados mostraram: a) ausência de atividade antimicrobiana para todas as cepas testadas, isto é, B. cereus, B. stearothermophilus, B. subtilis, E. aerogenes, E. coli, K. pneumoniae, M. luteus, P. mirabilis, P. aeruginosa, S. typhimurium, S. aureus, S. epidermidis, S. pyogenes, S. salivarius, C. albicans, C. neoformans e S. cerevisiae, independentemente das concentrações (72,6-145,2 mg/mL); b) ausência de efeitos sobre o crescimento e a diferenciação celular de H. samuelpessoai; c) ausência de efeitos potencialmente clastogênico e/ou aneugênico, independentemente de sexo, tempo e dosagem. Esses dados sugerem que o extrato de Pyrostegia venusta é seguro, podendo ser administrado por via tópica e oral, uma vez que não apresenta potencial carcinogênico/mutagênico. Pelas condições propostas o mesmo não deve ser usado como antimicrobiano.

This study aimed at analyzing the antibacterial and antifungic activity, the cell growth and differentiation in Herpetomonas samuelpessoai and the mutagenic action of the hydroalcoholic extract of Pyrostegia venusta (flame vine; ?cipó-de-são-joão? in Brazil). Antimicrobial activities were determined by agar diffusion and macrodilution techniques. Cellular growth and differentiation of H. samuelpessoai were assessed in a chemically defined medium at 28ºC/48 hours and quantitatively (Neubauer chamber) and qualitatively (pro-/para-/opistomatigote forms) analyzed after panoptic staining. Mutagenesis was evaluated by the micronucleus test in erythroblasts of Swiss albinus mice after treatment by gavage (1000-2000mg/kg) and 24-48 hours. The results showed (i) absence of antimicrobial activity for all the strains tested: B. cereus, B. stearothermophilus, B. subtilis, E. aerogenes, E. coli, K. pneumoniae, M. luteus, P. mirabilis, P. aeruginosa, S. typhimurium S. aureus, S. epidermidis, S. pyogenes, S. salivarius, C. albicans, C. neoformans and S. cerevisiae, independently of the concentrations (72.6-145.2mg/mL; (ii) absence of effects on the cellular growth and differentiation in H. samuelpessoai; and (iii) absence of potentially clastogenic and/or aneugenic effects, independently of sex, time and dose. These data suggest that the Pyrostegia venusta extract can safely be used topically and orally, once they do not exhibit carcinogenic/mutagenic effects, but under the conditions of this experiment it should not be used as antimicrobial agent.

Avaliação do potencial alelopático, atividade antimicrobiana e antioxidante dos extratos orgânicos das folhas de Pyrostegia venusta (Ker Gawl. ) Miers (Bignoniaceae) / Evaluation of allelopathic potential, antimicrobial and antioxidant activities of Pyrostegia venusta (Ker Gawl. ) Miers (Bignoniaceae) leaf organic extracts

Este trabalho apresenta os resultados de atividade alelopática, antimicrobiana e antioxidante dos extratos orgânicos (hexano, acetato de etila e metanol) das folhas de Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae). Para alelopatia, foi estudado o desenvolvimento de Cucumis sativus (pepino), sendo avaliados o comprimento da raiz principal, o número de raízes secundárias e o comprimento do hipocótilo. Os dois primeiros parâmetros foram afetados por todos os três extratos testados enquanto o comprimento do hipocótilo só não foi afetado pelo extrato acetato de etila. Quanto à atividade antimicrobiana, avaliada pelo ensaio de CIM, o extrato hexânico apresentou inibição moderada frente ao Staphylococcus aureus (0,9 mg mL-1) e forte ao Enterococcus hirae (0,5 mg mL-1). O extrato acetato de etila apresentou forte atividade frente Candida albicans (0,3 mg mL-1) enquanto o extrato metanólico não mostrou-se ativo para os microrganismos testados. Por outro lado, o extrato metanólico apresentou a maior capacidade de seqüestrar radicais livres (Concentração Efetiva 50 por cento-CE50 =102,0 ± 56,9 mg mL-1, com TCE50 = 30 min) no ensaio com DPPH (2,2-difenil-1-picril-hidrazila) e o maior teor de compostos fenólicos (116,2 ± 83,0 mg ácido gálico g amostra-1), avaliado pelo ensaio de Folin-Ciocalteau.

This paper presents the results of allelopathic, antimicrobial and antioxidant activities of organic extracts (hexane, ethyl acetate and methanol) from the leaves of Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae). Allelopathic activity was assessed based on Cucumis sativus (cucumber) development for the parameters main root length, number of secondary roots and hypocotyl length. All tested extracts affected the first two parameters, while the hypocotyl length was not affected only by the ethyl acetate extract. For antimicrobial activity, assessed by MIC assay, hexane extract showed moderate inhibition for Staphylococcus aureus (0.9 mg mL-1) and strong inhibition for Enterococcus hirae (0.5 mg mL-1). Ethyl acetate extract showed strong activity against Candida albicans (0.3 mg mL-1), whereas methanolic extract was not active against the tested microorganisms. On the other hand, methanol extract showed the most promising radical scavenging capacity (Effective Concentration 50 percent - EC50 = 102.0 ± 56.9 mg mL-1, with TEC50 = 30 min) in DPPH assay (2,2-diphenyl-1-picryl-hidrazil) and the highest level of phenolic compounds (116.2 ± 83.0 mg acid garlic g sample-1), as indicated by Folin-Ciocalteau assay.

Avaliação do potencial genotóxico do extrato bruto de Pyrostegia venusta (Ker Gawl. ) Miers, Bignoneaceae, em medula óssea de camundongos / The Evaluation of the genotoxic potency of the Pyrostegia venusta (Ker Gawl. ) Miers, Bignoneaceae, crude extract on bone marrow of mice

Pyrostegia venusta (Ker Gawl.) Miers, Bignoneaceae, é utilizada no tratamento de vitiligo e de outras doenças, mas seus efeitos genotóxicos não são conhecidos. Neste sentido, o presente estudo teve por objetivo avaliar o efeito genotóxico de extratos de P. venusta em camundongos utilizando os Testes de Micronúcleo (MN) e o de Aberração Cromossômica (AC). O vegetal foi coletado, selecionado, seco, triturado e extraído com etanol. Camundongos de 40 g foram divididos em grupos experimentais e controles. Os grupos experimentais receberam concentrações crescentes do extrato (50, 100 e 200 mg/kg por peso corporal), por v.o. O grupo controle negativo (CN) recebeu água. O grupo controle positivo (CP) recebeu Ciclofosfamida® por v.i. Realizou-se o sacrifício, retirada da medula óssea, homogeneização e preparação das lâminas. As freqüências de eritrócitos policromáticos micronucleados (EPCMN) foram: CN = 0,35±0,09; CP = 2,87±1,78; 50 = 0,09±0,04; 100 = 0,16±0,08 e 200 = 0,10±0,03. O teste de AC apresentou as seguintes freqüências: CN = 0,12±1,87; CP = 0,62±5,61; 50 = 0,12±1,58; 100 = 0,072±0,54 e 200 = 0,124±1,64. As freqüências de EPCMN dos grupos experimentais foram significantemente inferiores quando comparadas com as dos controles. A freqüência de cromossomos aberrantes não teve diferença significativa se comparada com o CN, mas foi estatisticamente menor que a do CP. P.venusta não apresentou atividade genotóxica.

Pyrostegia venusta (Ker Gawl.) Miers, Bignoneaceae, is used in the treatment of vitiligo and other diseases, but its genotoxic effects are unknown. In this way, this study aimed to evaluate the genotoxic effect of extracts of P. venusta in mice using the micronucleus (MN) and chromosome aberration tests (CA). The plant was collected, selected, dried, pounded and extracted with ethanol. Mice weighing 40 g were divided in experimental and control groups. The experimental groups received different concentrations (50, 100, and 200 mg/kg body weight), by oral gavage. The negative control group (NC) received water. The positive control group (PC) received Ciclophosphamide® by v.i. It was performed the sacrifice, removal of bone marrow, homogenization and slides preparation. Frequency of micronucleated polychromatic erythrocytes (MNPCE) was: NC = 0.35±1.87; PC = 2.87±9.02; 50 = 0.09±0.83; 100 = 0.16±0.10 e 200 = 0.10±0.71. The CA test showed the frequency: NC = 0.12±1.87; PC = 0.62±5.61; 50 = 0.12±1.58; 100 = 0.072±0.54 e 200 = 0.124±1.64. The frequency of MNPCE of experimental controls was significantly lower when compared with NC, but it was statistically lower than PC's frequency. P.venusta didn't show genotoxicity activity.