RESUMO
Vernonia condensata Baker is traditionally used to treat several inflammatory and infectious processes. So, this study evaluated the antibiotic, synergistic and antibiofilm effects, and the mode of action of ethyl acetate fraction from V. condensata leaves (Vc-EAF) against Staphylococcus aureus. Five S. aureus ATCC® and five methicillin-resistant S. aureus (MRSA) routine strains were used to determine Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration. The combinatory effect was evaluated by checkerboard and time kill methods; the mode of action through the bacterial cell viability and leakage of compounds absorbing at 280â¯nm; and the antibiofilm action by quantifying the percentage of adhesion inhibition. Vc-EAF was active against S. aureus (ATCC® 6538™), (ATCC® 25923™), (ATCC® 29213™), (ATCC® 33591™), (ATCC® 33592™), MRSA 1485279, 1605677, 1664534, 1688441 and 1830466, with MIC of 625⯵g/mL for ATCC®, and 1250, 1250, >2500, 2500 and 2500⯵g/mL for MRSA, in this order, with bacteriostatic effect for both ATCC® and MRSA strains. Vc-EAF plus ampicillin revealed a total synergic effect on MRSA 1485279, and Vc-EAF combined with chloramphenicol, a partial synergic action against S. aureus (ATCC® 29213™) and (ATCC® 25923™). The time kill data agreed with checkerboard results, and the treated cells number was reduced with release of bacterial content. An expressive bacterial adhesion inhibition for S. aureus (ATCC® 25923™) and MRSA 1485279 was detected. These results showed that V. condensata is a promising natural source of active substances against S. aureus, including multiresistant strains, interfering with their antibacterial growth and hampering their adhesion to surfaces.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Vernonia/química , Ampicilina/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Cloranfenicol/farmacologia , Combinação de Medicamentos , Sinergismo Farmacológico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Folhas de Planta/químicaRESUMO
ABSTRACT The aim of this study was to provide scientific knowledge to support the use of Vernonia condensata Baker, Asteraceae, beverages for their alleged hypocholesterolemic properties by testing their action as HMG-CoA reductase inhibitors and their capacity to lower dietary cholesterol permeation. Chlorogenic acid, and other caffeoylquinic acids derivatives were identified as the main components of these beverages by LC–MS/MS. No changes in the composition were notice after the in vitro gastrointestinal digestion and no toxicity against Caco-2 and HepG2 cell lines was detected. Cholesterol permeation through Caco-2 monolayers was reduced in 37% in the presence of these herbal teas, and the caffeoylquinic acids permeated the monolayers in 30–40% of their initial amount in 6 h. HMG-CoA reductase activity was reduced with these beverages, showing an IC50 of 217 µg ml−1. It was concluded that caffeoylquinic acids, the major components, justified 98% of the enzyme inhibition measured.
RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: The leaves from Vernonia condensata Baker are broadly used in folk medicine for the treatment of gastric ulcers and dyspepsia. The Brazilian Public Health System (SUS) describes this species as having the potential to serve as a new herbal product with therapeutic benefits. AIM OF THE STUDY: The purpose of the study was to evaluate the gastroprotective activity and gastric healing properties of a crude ethanolic extract from leaves of V. condensata (CEEV) in different animal models. MATERIALS AND METHODS: In order to assess the gastroprotective potential of CEEV, ulcer models were established using ethanol and indomethacin. The gastric healing effect was then evaluated in the acetic acid-induced ulcer model, where the tissue was used to assess oxidative levels (reduced glutathione and lipid hydroperoxide levels, as well as superoxide dismutase and catalase activity), inflammatory [myeloperoxidase (MPO)] parameters, and mucin content. Furthermore, the ligature pylorus model, with and without secretagogue stimuli, was employed to investigate the mechanism of action of CEEV. In addition, H(+)K(+)-ATPase activity, MPO activity, and antioxidant activity through the DPPH assay were examined through in vitro trials. Phytochemical analyses were also performed. The ethanol/HCl-induced gastric ulcer method was employed to verify the gastroprotective effect of the main compound in CEEV. RESULTS: CEEV (30 and 300mg/kg, p.o) exhibited gastroprotective activity and prevented both gastric lesions induced by ethanol or indomethacin in rats. The gastric healing effect of CEEV (300mg/kg, p.o. taken twice a day for a duration of seven days) was confirmed by examining the macroscopic and microscopic appearance of chronic gastric ulcers induced by acetic acid in rats. The restorative effect of CEEV was accompanied by a significant increase in mucin content (PAS staining) and by a reduction in oxidative stress and inflammatory parameters at the site of the ulcer. Moreover, CEEV (300mg/kg), administered via an intraduodenal route, significantly reduced the volume, pH, total acidity and pepsin activity of gastric content in the pylorus ligature model in rats. The gastric acid antisecretory effect of CEEV was maintained even in the presence of cholinergic and gastrinergic, but not histaminergic, stimuli. In vitro, CEEV (1-10µg/ml) was able to scavenge free radical DPPH, but did not promote inhibitory effects on MPO or H(+),K(+)-ATPAse activity. Phytochemical analysis of CEEV indicated that luteolin is the main compound present in the extract. However, luteolin (1, 3 and 10mg/kg, p.o or 1mg/kg, i.p.) did not promote gastroprotection against ethanol/HCl in mice. It is also important to mention that oral administration of CEEV did not produce any sign of acute toxicity in animals. CONCLUSIONS: V. condensata extract demonstrates gastroprotective effects through the inhibition of gastric secretion via cholinergic and gastrinergic pathways. Furthermore, it exhibits cytoprotective effects, involving antioxidant activity, an increase in mucin content and inhibition of neutrophil migration. Thus, this medicinal plant may be a suitable natural source for the prevention and treatment of gastric lesions.
Assuntos
Antiulcerosos , Gastrite/tratamento farmacológico , Extratos Vegetais , Úlcera Gástrica/tratamento farmacológico , Vernonia , Animais , Antiulcerosos/química , Antiulcerosos/farmacologia , Antiulcerosos/uso terapêutico , Catalase/metabolismo , Etanol , Feminino , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Gastrite/induzido quimicamente , Gastrite/metabolismo , Gastrite/patologia , Glutationa/metabolismo , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Indometacina , Camundongos , Mucinas/metabolismo , Peroxidase/metabolismo , Fenóis/análise , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta , Plantas Medicinais , Coelhos , Ratos Wistar , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/metabolismo , Úlcera Gástrica/patologia , Superóxido Dismutase/metabolismoRESUMO
O uso de plantas medicinais tem sido uma prática antiga da humanidade, contribuindo para a divulgação das virtudes terapêuticas de extratos de diferentes vegetais. Na busca de alternativas naturais eficazes para males que prejudicam indiretamente o homem, as plantas medicinais têm sido utilizadas na veterinária na tentativa de eliminar ou reduzir a ação dos carrapatos B. microplus, que podem trazer prejuízos a bovinos. Durante anos têm sido utilizado produtos químicos nesse controle, no entanto, os carrapatos adquirem resistência aos fármacos em decorrência do uso contínuo. Assim, objetivou-se avaliar o efeito de hidrolato e extratos aquosos de carqueja [Baccharis trimera (Less). D.C.], alfavaca (Ocimum gratissimum L.), necroton [Vernonia condensata (Backer) H. Rob.] camomila [Chamomilla recutita (L.) Rauschert], além do óleo essencial de alfavaca (Ocimum gratissimum L.). Os ensaios para larvas de B. microplus foram realizados com impregnação das substâncias em papel filtro. Os resultados obtidos demonstraram que todos os extratos aquosos foram ineficazes; o hidrolato de carqueja e de necroton apresentaram eficiência em torno de 30%, necessitando novos testes para comprovação. Dentre os resultados obtidos, destaca-se o hidrolato de alfavaca que apresentou eficiência de 76,7% na concentração de 100% e o óleo essencial puro de alfavaca que apresentou ação larvicidade 100% indicando o potencial carrapaticida dessa planta, especificamente no combate de B.microplus.
The use of medicinal plants has been a longstanding practice of mankind, helping to spread the therapeutic virtues of different plant extracts, due to their medicinal effects. In the search for effective natural alternatives for ailments that indirectly affect man, medicinal plants have been used in veterinary medicine, in an attempt to eliminate or reduce the action of B. microplus ticks, which can cause damage to cattle. For many years, chemical products have been used in this control. However, after some time ticks acquire drug resistance, as a result of continuous use. Thus, the objective of this paper was to evaluate the effect of hydrolates and aqueous extracts of carqueja [Baccharis trimera (Less). DC], alfavaca (Ocimum gratissimum L.), necroton [Vernonia condensata (Baker) H. Rob.], chamomile [Chamomilla recutita (L.) Rauschert] and also the essential oil of alfavaca (Ocimum gratissimum L.). The assays for larvae of B. microplus were carried out by impregnating the paper filter with the substances. The results showed that all the aqueous extracts were ineffective; the hydrolate of carqueja and necroton presented efficiencies around 30%, requiring further tests to prove. Among the results, we observed that the alfavaca hydrolate showed an efficiency of 76.7% at a concentration of 100% and the pure alfavaca oil showed a larvicidal action of 100%, indicating this plant's potential to reduce ticks, specifically in the control of B. microplus.
Assuntos
Plantas Medicinais/efeitos adversos , Óleos Voláteis/análise , Rhipicephalus , Carrapatos , Baccharis/metabolismo , Matricaria/metabolismo , Ocimum/metabolismo , Acaricidas/análiseRESUMO
The present study was aimed at evaluating the antinociceptive and anti-inflammatory effects of the ethanol extract from Vernonia condensata leaves in animal models, in order to afford a better understanding of these properties. The extract reduced the number of abdominal contortions at doses of 100 (51.00 ± 3.00), 200 (42.00 ± 2.98) and 400 mg/kg (39.00 ± 4.00). In formalin tests, a significant reduction in the licking time (p < 0.01) was observed in the first phase by 25.14 (200 mg/kg = 51.50 ± 4.44) and 31.15% (400 mg/kg = 48.00 ± 4.37). The doses of 100 (43.37 ± 5.15), 200 (34.62 ± 4.16) and 400 mg/kg (28.37 ± 3.98) inhibited (p < 0.001) the second phase. After 60 and 90 min of treatment, a dose of 400 mg/kg (10.13 ± 0.39 and 11.14 ± 1.33, respectively) increased the latency time. Doses of 200 and 400 mg/kg potentiated the sleeping time induced by diazepam, pentobarbital and meprobamate. The extracts (100, 200 and 400 mg/kg) showed anti-inflammatory effects by a decrease in paw edema. The extracts also reduced the exudate volume at the doses of 200 and 400 mg/kg. The leukocyte migration had significant effect (p < 0.001) at doses of 100, 200 and 400 mg/kg. The completion of additional experiments in the investigation of the antinociceptive and anti-inflammatory activities of V. condensata allowed a better understanding of the central and peripheral mechanisms involved.
Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios/farmacologia , Extratos Vegetais/farmacologia , Veronica/química , Analgésicos/efeitos adversos , Animais , Etanol/química , Masculino , Camundongos , Nociceptividade/efeitos dos fármacos , Extratos Vegetais/efeitos adversos , Folhas de Planta/química , Ratos , Ratos Wistar , Sono/efeitos dos fármacosRESUMO
ABSTRACT Chemical agents produced by some plants may cause changes on the development of other plants and organisms. Laboratory assays can show the results of these interactions, however, without considering the environmental action. Theaimof this work was to identify the influence of plant extracts from 3 species of plants usually known in Brazil as boldo on the development of Allium cepa seeds. Bioassay were carried out in a germinator at 25° C with aqueous extract obtainedby infusion of the fresh leaves in concentration of 30 g.L-1 and distilled water as a control. The first score and germination tests that evaluated allelopathic effect were done with 4 repetitions of 50 seeds/extract. For the cytotoxicity assay, using mitotic index (MI), 2,400 cells/extract were scored through the scan technique. The bioassay revealed that the plant extracts act on the A. cepa germination and root-tip cell division. Seeds exposed to Vernonia condensata extract showed the highest divergence when compared with the control group.
RESUMO Agentes químicos produzidos em algumas plantas podem provocar alterações no desenvolvimento de outras plantas ou até mesmo de outros organismos. Ensaios laboratoriais podem demonstrar os resultados destas interações, porém, sem considerar a ação do ambiente. Com este trabalho objetivou-se identificar a influência de extratos vegetais de 3 espécies conhecidas no Brasil popularmente como boldo sobre o desenvolvimento de Allium cepa. Os bioensaios foram conduzidos em germinador a 25° C, com extrato aquoso obtido por infusão de folhas frescas na concentração de 30 g.L-1 e água destilada como controle. Os testes de primeira contagem e germinação, que avaliam efeito alelopático foram realizados com 4 repetições de 50 sementes. Para determinação da citotoxicidade, através do índice mitótico (IM) foram contadas pela técnica de varredura 2.400 células por extrato. Os bioensaios realizados revelaram que os extratos vegetais interferiram sobre a germinação e sobre a divisão celular em células meristemáticas radiculares de A. cepa. Sementes expostas ao extrato de Vernonia condensata apresentaram as maiores divergências em relação ao grupo controle.
RESUMO
Rearing leafhopper (Hemiptera: Cicadellidae) vectors free of Xylella fastidiosa is a requirement for studies of various aspects of vector-pathogen interactions. The selection of a plant that allows vector development but not bacterial multiplication is desirable to produce healthy vectors. In this study, two leafhopper hosts, Vernonia condensata ('boldo') and Aloysia virgata ('lixeira') were needle inoculated with citrus and coffee strains of X. fastidiosa to evaluate if these plants support pathogen colonization. The inoculated plants did not present symptoms and the pathogen was not detected by culture and PCR tests, neither soon after inoculation (7-14 days) nor later, at 1, 4, 6 and 12 months after inoculation. To obtain healthy adults of the leafhopper vectors Acrogonia citrina, Bucephalogonia xanthophis, Dilobopterus costalimai, Homalodisca ignorata and Oncometopia facialis, early-instar nymphs were reared on V. condensata. X. fastidiosa was not detected in any of 175 adults obtained. V. condensata and A. virgata are nonpropagative hosts of X. fastidiosa and enable the production of healthy leafhoppers for vector studies.
A obtenção de cigarrinhas (Hemiptera: Cicadellidae) livres de Xylella fastidiosa é importante para estudos de interação entre essa bactéria e seus vetores, sendo desejável a seleção de uma planta que permita a criação desses insetos, mas não a multiplicação da bactéria. Neste estudo, duas plantas hospedeiras de cigarrinhas, Vernonia condensata (boldo) e Aloysia virgata (lixeira), foram inoculadas por agulha com as estirpes de citros e de cafeeiro de X. fastidiosa, para avaliar a possibilidade deste patógeno colonizá-las. Não foram observados sintomas, nem se detectou a bactéria por isolamento em meio de cultura e/ou PCR em períodos curtos (7 e 14 dias) ou longos (1, 4, 6 e 12 meses) após a inoculação. Para obtenção de adultos sadios das cigarrinhas vetoras, Acrogonia citrina, Bucephalogonia xanthophis, Dilobopterus costalimai, Homalodisca ignorata e Oncometopia facialis, ninfas de primeiros ínstares foram criadas em plantas de boldo. Não foi detectada X. fastidiosa em nenhum de 175 adultos obtidos da criação. V. condensata e A. virgata não permitem a colonização de X. fastidiosa, possibilitando assim a obtenção de cigarrinhas sadias para estudos com vetores.
RESUMO
Rearing leafhopper (Hemiptera: Cicadellidae) vectors free of Xylella fastidiosa is a requirement for studies of various aspects of vector-pathogen interactions. The selection of a plant that allows vector development but not bacterial multiplication is desirable to produce healthy vectors. In this study, two leafhopper hosts, Vernonia condensata ('boldo') and Aloysia virgata ('lixeira') were needle inoculated with citrus and coffee strains of X. fastidiosa to evaluate if these plants support pathogen colonization. The inoculated plants did not present symptoms and the pathogen was not detected by culture and PCR tests, neither soon after inoculation (7-14 days) nor later, at 1, 4, 6 and 12 months after inoculation. To obtain healthy adults of the leafhopper vectors Acrogonia citrina, Bucephalogonia xanthophis, Dilobopterus costalimai, Homalodisca ignorata and Oncometopia facialis, early-instar nymphs were reared on V. condensata. X. fastidiosa was not detected in any of 175 adults obtained. V. condensata and A. virgata are nonpropagative hosts of X. fastidiosa and enable the production of healthy leafhoppers for vector studies.
A obtenção de cigarrinhas (Hemiptera: Cicadellidae) livres de Xylella fastidiosa é importante para estudos de interação entre essa bactéria e seus vetores, sendo desejável a seleção de uma planta que permita a criação desses insetos, mas não a multiplicação da bactéria. Neste estudo, duas plantas hospedeiras de cigarrinhas, Vernonia condensata (boldo) e Aloysia virgata (lixeira), foram inoculadas por agulha com as estirpes de citros e de cafeeiro de X. fastidiosa, para avaliar a possibilidade deste patógeno colonizá-las. Não foram observados sintomas, nem se detectou a bactéria por isolamento em meio de cultura e/ou PCR em períodos curtos (7 e 14 dias) ou longos (1, 4, 6 e 12 meses) após a inoculação. Para obtenção de adultos sadios das cigarrinhas vetoras, Acrogonia citrina, Bucephalogonia xanthophis, Dilobopterus costalimai, Homalodisca ignorata e Oncometopia facialis, ninfas de primeiros ínstares foram criadas em plantas de boldo. Não foi detectada X. fastidiosa em nenhum de 175 adultos obtidos da criação. V. condensata e A. virgata não permitem a colonização de X. fastidiosa, possibilitando assim a obtenção de cigarrinhas sadias para estudos com vetores.