Antiangiogenic potential of Jatropha curcas latex in the chick chorioallantoic membrane model / Potencial antiangiogênico do látex de Jatropha curcas em modelo de membrana corioalantoica de embrião de galinha

AIMS: To perform a physicochemical and phytochemical characterization of Jatropha curcas latex and to investigate its antiangiogenic potential. METHODS: We performed an initial physicochemical characterization of J. curcas latex using thermal gravimetric analyses and Fourier Transform Infrared spectroscopy. After that, phenols, tannins and flavonoids were quantified. Finally, the potential of J. curcas latex to inhibit angiogenesis was evaluated using the chick chorioallantoic membrane model. Five groups of 20 fertilized chicken eggs each had the chorioallantoic membrane exposed to the following solutions: (1) water, negative control; (2) dexamethasone, angiogenesis inhibitor; (3) Regederm®, positive control; (4) 25% J. curcas latex diluted in water; (5) 50% J. curcas latex diluted in water; and (6) J. curcas crude latex. Analysis of the newly-formed vascular net was made through captured images and quantification of the number of pixels. Histological analyses were performed to evaluate the inflammation, neovascularization, and hyperemia parameters. The results were statically analyzed with a significance level set at p<0.05. RESULTS: Physicochemical characterization showed that J. curcas latex presented a low amount of cis-1.4-polyisoprene, which reduced its elasticity and thermal stability. Phytochemical analyses of J. curcas latex identified a substantial amount of phenols, tannins, and flavonoids (51.9%, 11.8%, and 0.07% respectively). Using a chick chorioallantoic membrane assay, we demonstrated the antiangiogenic potential of J. curcas latex. The latex induced a decrease in the vascularization of the membranes when compared with neutral and positive controls (water and Regederm®). However, when compared with the negative control (dexamethasone), higher J. curcas latex concentrations showed no significant differences. CONCLUSIONS: J. curcas latex showed low thermal stability, and consisted of phenols, tannins, and flavonoids, but little or no rubber. Moreover, this latex demonstrated a significant antiangiogenic activity on a chick chorioallantoic membrane model. The combination of antimutagenic, cytotoxic, antioxidant and antiangiogenic properties makes J. curcas latex a potential target for the development of new drugs.

OBJETIVOS: Realizar uma caracterização físico-química e fitoquímica do látex de Jatropha curcas e investigar o seu potencial antiangiogênico. MÉTODOS: foi realizada uma caracterização físico-química inicial do látex de J. curcas utilizando as análises termogravimétricas e a espectroscopia com a Transformada de Fourier. Depois disso, fenóis, taninos e flavonoides foram quantificados. Finalmente, o potencial do látex de J. curcas em inibir a angiogênese foi avaliado através do uso de modelo de membrana corioalantoica de embrião de galinha. Cinco grupos, cada um com 20 ovos de galinha fertilizados, tiveram a membrana corioalantoica exposta às seguintes soluções: (1) água, controle negativo; (2) dexametasona, inibidor da angiogênese; (3) Regederm®, controle positivo; (4) 25% de látex de J. curcas diluído em água; (5) 50% de látex de J. curcas diluído em água; e (6) látex bruto de J. curcas. A análise da rede vascular recém-formada foi feita por meio de imagens capturadas e quantificação do número de pixels. Análises histológicas foram realizadas para avaliar os parâmetros de inflamação, neovascularização e hiperemia. Os resultados foram analisados estaticamente com nível de significância estabelecido em p<0,05. RESULTADOS: A caracterização físico-química mostrou que o látex de J. curcas apresenta uma baixa quantidade de cis-1,4-poliisopreno, o que reduz sua elasticidade e estabilidade térmica. Análises fitoquímicas do látex de J. curcas identificaram uma quantidade significativa de fenóis, taninos e flavonoides (51,9%, 11,8% e 0,07% respectivamente). Usando o modelo de membrana corioalantoica de ovo de galinha embrionado, demonstrou-se o potencial antiangiogênico do látex de J. curcas. O látex induziu a diminuição da vascularização das membranas, em comparação aos grupos controle neutro e positivo (água e Regederm®). CONCLUSÕES: O látex de J. curcas apresentou baixa estabilidade térmica, ausência ou pouca quantidade de borracha e presença de fenóis, taninos e flavonoides em sua composição. Além disso, apresentou alta atividade antiangiogênica no modelo de membrana corioalantoica de embrião de galinha. A combinação de propriedades antimutagênicas, citotóxicas, anti-inflamatórias, antioxidantes e antiangiogênicas faz com que o látex de J. curcas seja um alvo potencial para o desenvolvimento de novos medicamentos.

Toxicity of Jatropha curcas L. latex in Allium cepa test / Toxicidade do látex de Jatropha curcas L. no modelo de Allium cepa

The latex obtained from Jatropha curcas (physic nut) is used in traditional medicine to treat a variety of disturbs, including burns, hemorrhoids, ringworm and ulcers. Phytochemical analyses have shown that J. curcas latex contains natural compounds with therapeutic potential. In this study, the toxicity, cytotoxicity and genotoxicity effects of J. curcas latex on the root cells of Allium cepa were examined. Onion seeds and bulbs were exposed to seven different concentrations of latex and then the roots were submitted to macro and microscopic analyses. Water and sodium azide were used as negative and positive controls, respectively. The analysis of root growth showed that J. curcas crude latex or 50% diluted is highly toxic. Cytogenetic results showed that the mitotic index of the onion roots submitted to latex treatment decreased significantly compared to the negative control, which suggests that the latex is cytotoxic. High incidence of chromosome aberrations in the cells treated with J. curcas latex was observed too, indicating that the latex also presents genotoxic effect. The analyses presented in this report suggest the toxic, cytotoxic and genotoxic effects of J. curcas latex. Then, the indiscriminate use of J. curcas latex in folk medicine could bring risk to human health.

O látex obtido de Jatropha curcas (pinhão manso) é usado na medicina tradicional para tratamento de diversos distúrbios, como queimaduras, hemorroida, micose e úlcera. Análises fitoquímicas apontaram que o látex de J. curcas contém compostos naturais com potencial terapêutico. Este estudo avaliou a toxicidade, citotoxicidade e genotoxicidade do látex de J. curcas em células da raiz de Allium cepa. Sementes e bulbos de cebola foram expostos á sete diferentes concentrações de látex e, então, as raízes foram submetidas a análises macro e microscópica. Água e azida sódica foram utilizadas como controle negativo e positivo, respectivamente. A análise do comprimento das raízes mostrou que o látex de J. curcas puro e diluído a 50% é altamente tóxico. O índice mitótico das raízes de cebola submetidas ao tratamento com o látex diminuiu significativamente comparado com o controle negativo, o que sugere que o látex é citotóxico. Uma alta incidência de aberrações cromossômicas em células tratadas com o látex de J. curcas também foi observada, indicando que o látex apresenta efeito genotóxico. Essa análise sugere que o látex de J. curcas possui efeitos tóxico, citotóxico e genotóxico, sendo que o uso indiscriminado do látex de J. curcas na medicina popular pode trazer risco à saúde humana.

Growth of J. curcas seedlings under water deficit condition / Crescimento de mudas de Jatropha curcas em condição de déficit hídrico

The elucidation of drought tolerance mechanisms in plants may facilitate the commercial exploitation of the species J. curcas in semi-arid regions. This study was designed to evaluate the growth and drought tolerance strategy of J. curcas plants grown under different water regimes. The work was carried out on an outdoor bench in full sunlight at Goiás State University, following the completely randomized experiment design with a 2x2 factorial scheme (two wild populations of J. curcas, naturally found in the states of São Paulo and Goiás, and two water supply regimes: 0% and 100% of evapotranspiration) and five replications. First a mixture of soil, sand and manure was prepared at the ratio of 3:1:0.5, respectively. The plants were irrigated daily, and at 60 days of age they were subjected to 10 days of water deficit and then rehydrated for five days. Under water deficit condition the J. curcas plants decreased the shoot growth, adjusted the leaf area to reduce the transpiration rate and increased the root system growth. J. curcas plants delay dehydration as a strategy to tolerate water deficit, for which the species reduces the transpiration rate and sustains tissue hydration using the water stored in the succulent stem.

A elucidação dos mecanismos de tolerância a seca poderá viabilizar a exploração comercial da espécie J. curcas em regiões semi-áridas. Pretendeu-se avaliar o crescimento e a estratégia de tolerância a seca de plantas de J. curcas cultivadas sob diferentes regimes hídricos. O trabalho foi conduzido em bancada a pleno sol na Universidade Estadual de Goiás, seguindo o delineamento experimental inteiramente casualizado, em esquema fatorial de 2x2 (duas populações silvestres de J. crucas encontradas naturalmente nos estados de São Paulo e Goiás e dois suprimentos hídricos: 0% e 100% da evapotranspiração) e cinco repetições Inicialmente foi preparada uma mistura de solo, areia e esterco na proporção de 3:1:0,5, respectivamente. As plantas foram irrigadas diariamente e aos 60 dias de idade, as mesmas foram submetidas a 10 dias de déficit hídrico e, em seguida, reidratadas por cinco dias. Em condição de déficit hídrico as plantas de J. curcas reduzem o crescimento da parte aérea, ajustam a área foliar para reduzir a taxa transpiratória e intensificam o crescimento do sistema radicular. As plantas de J. curcas apresentam como estratégia de tolerância ao déficit hídrico, o retardo da desidratação, para tal, a espécie reduz a taxa transpiratória e matem a hidratação dos tecidos utilizando a água armazenada no caule suculento.

Growth of seedlings Jatropha curcas L. irrigated with saline water / Crescimento de mudas de pinhão manso, Jatropha curcas L. irrigadas com água salina

The species Jatropha curcas is a rustic plant, adapted to several edaphoclimatic conditions, being constantly explored in marginal conditions, however, ensuring production will be greater with the use of irrigation and fertile soil, when it'll be necessary to research the possibility of its cultivation with saline water. Therefore the present study aims at assessing the effect of the electrical conductivity of irrigation water on the morphophysiological answers of seedlings from J. curcas L. The work was conducted in shade with 50% of solar radiation interception at the State University of Goiás. The experiment was set up following a completely randomized design with four treatments and five repetitions. Sowing occurred in four-liter containers containing soil, sand and manure in the ratio of 3: 1: 0.5 respectively. During the seedling stage (60 days), the plants were subjected to four treatments: plants irrigated daily with 150 ml of deionized water containing NaCl, and electrical conductivity of 0.0 dS m-1 (T1), 3 dS m-1 (T2), 6 dS m-1 (T3) and 9 dS m-1 (T4). The high concentration of salt reduced the free energy of the water, making it limiting. The water limitation caused a reduction in the leaf area and in the number of leaves, contributing to the reduction of perspiring area and the maintenance of tissue hydration. The high electrical conductivity of irrigation water reduced the seedling growth J. curcas, however, plants of J. curcas can be irrigated with saline water of conductivity less than or equal to 3 dS m-1 without significant damage to vegetative growth.

Susceptibility and physiological responses of Jatropha curcas accessions to broad mite infestation.

The broad mite Polyphagotarsonemus latus is a key pest of physic nut (Jatropha curcas L.). The purpose of this study was to identify physic nut accessions that are less susceptible to P. latus, in support of the breeding program of J. curcas. We first evaluated population growth rate and injury symptoms of P. latus on different J. curcas accessions and then carried out physiological analyses on P. latus-infested and uninfested accessions. From the germplasm bank of the Federal University of Viçosa, 15 physic nut accessions with high seed oil content, with different genetic background, were tested. The following traits were evaluated: instantaneous population growth rate of P. latus (r i ), injury symptoms, relative leaf water content, specific leaf area, gas exchange, photosynthetic pigments, nitrogen and biomass of the aerial part. Significant differences were observed for P. latus population growth rate and injury symptoms among accessions. A positive correlation between P. latus growth rate and injury was found. The UFVJC72 accession stood out as the more resistant, considering P. latus growth rate and injury symptoms, compared with most accessions. Physiological responses did not vary among accessions, but did between infested and uninfested plants. In P. latus-infested plants, net photosynthesis was on average 50.5 % lower than in uninfested plants, whereas stomatal conductance and transpiration decreased by 46.2 and 51.6 %, respectively.