Phytochemical analysis and biological activities of in vitro cultured Nidularium procerum, a bromeliad vulnerable to extinction.

This study reports the first phytochemical and biological characterization in treatment of adrenocortical carcinoma cells (H295R) of extracts from Nidularium procerum, an endemic bromeliad of Atlantic Forest vulnerable to extinction. Extracts of dry leaves obtained from in vitro-grown plants were recovered by different extraction methods, viz., hexanoic, ethanolic, and hot and cold aqueous. Chromatography-based metabolite profiling and chemical reaction methods revealed the presence of flavonoids, steroids, lipids, vitamins, among other antioxidant and antitumor biomolecules. Eicosanoic and tricosanoic acids, α-Tocopherol (vitamin E) and scutellarein were, for the first time, described in the Nidularium group. Ethanolic and aqueous extracts contained the highest phenolic content (107.3 mg of GAE.100 g-1) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity, respectively. The immunomodulatory and antitumoral activities of aqueous extracts were assessed using specific tests of murine macrophages modulation (RAW 264.7) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against adrenocortical carcinoma cell line, respectively. The aqueous extract improved cell adhesion and phagocytic activities and phagolysossomal formation of murine macrophages. This constitutes new data on the Bromeliaceae family, which should be better exploited to the production of new phytomedicines for pharmacological uses.

A comparative study of extraction techniques for maximum recovery of bioactive compounds from Ganoderma lucidum spores / Estudio comparativo de técnicas de extracción para la máxima recuperación de compuestos bioactivos a partir esporas de Ganoderma lucidum

SUMMARY This study aimed at evaluating effective methods for breaking the hard and insoluble spores of Ganoderma lucidum to recover functional biomolecules. Rupture techniques were evaluated such as manual maceration (RM), maceration with spheres of various materials (BR), and microwave exposure plus maceration with steel/ chrome spheres (MBR1). Spore rupture was evaluated using UV-Vis spectroscopy, which showed vibrations of 2955, 1642, 1240, 1080 and 1746 cm-1 corresponding to changes in spore walls. The MBR1 extract contained the largest amounts of carbohydrates (19.80 mg.g-1 spores) and polyphenols (2.21 mg.g-1 spores), whereas the BR extract had higher antioxidant activity (57.22%Inb DPPH). The MBR1 and BR extracts contained 62.2 and 73.5% glucose, respectively. Both methods also involved significant extraction of carbohydrates and proteins. The best way to extract biomolecules from spore walls is to perform a microwave heat treatment and break the walls with steel/chrome spheres; this produces large quantities of carbohydrates with antioxidant properties.

RESUMEN El objetivo de este estudio fue evaluar varios métodos de ruptura de las esporas de Ganoderma lucidum y extraer sus propiedades bioactivas. Para este propósito se evaluaron diferentes técnicas de rompimiento como: la maceración manual (RM), la maceración con esferas de diversos materiales (BR) y la exposición a microondas junto la maceración de las esporas con esferas de acero/cromo (MBR1). La ruptura de las esporas fue evaluada por espectroscopia UV-Vis, la cual mostró que las vibraciones 2955, 1642, 1240, 1080 y 1746 cm-1 correspondieron a cambios estructurales en las paredes de las esporas. El extracto MBR1 presento el mayor contenido de carbohidratos (19,80 mg.g-1) y polifenoles (2,21 mg.g-1), mientras que el extracto BR tuvo una mayor actividad antioxidante (57,22% Inb DPPH). Los extractos MBR1 y BR también presentaron en el análisis de monosacáridos un 62,2 y 73,5% de contenido glucosa. Como conclusión la mejor metodología para extraer biomoléculas de las paredes de las esporas de G. lucidum fueron el tratamiento térmico con microondas y la ruptura de las paredes con esferas de acero/cromo, porque este proceso permitió la extracción de una mayor cantidad de carbohidratos con posibles propiedades antioxidantes.

Water relations and photosynthetic capacity of two species of Calotropis in a tropical semi-arid ecosystem.

BACKGROUND AND AIMS: Calotropis procera and Calotropis gigantea, originally from warm parts of Africa and Asia, are now pan-tropical and in ecological terms considered an indicator of overgrazed, disturbed lands; they grow successfully in dry areas. Variations in water relations, morphology and photosynthesis of the two species growing in the same habitat were studied to assess possible mechanisms of tolerance to drought and how these relate to their ecophysiological success. Also the hypothesis that their photosynthetic rate (A) under drought would be affected by stomatal and non-stomatal limitations was tested. METHODS: Water relations, gas exchange, water use efficiency (WUE), fluorescence parameters, pubescence and specific leaf area (SLA) of Calotropis procera and C. gigantea plants growing in the field were evaluated during the wet (WS) and dry (DS) seasons. RESULTS: The xylem water potential (ψ) was similar in both species during the WS and DS; drought caused a 28 % decrease of ψ. In C. procera, A, stomatal conductance (g(s)) and carboxylation efficiency (CE) were higher in the WS with half the values of those during the DS, this species being more affected by drought than C. gigantea. A high δ(13)C of C. gigantea (-26·2 ‰) in the WS indicated a higher integrated WUE, in agreement with its lower g(s). Leaves of C. gigantea were more pubescent than C. procera. Relative stomatal and non-stomatal limitation of A increased with drought in both species; no changes in maximum quantum yield of photosystem II (PSII; F(v)/F(m)) were observed. The decrease in the relative quantum yield of PSII (ϕ(PSII)) and in the photochemical quenching coefficient (q(P)) was more pronounced in C. procera than in C. gigantea. CONCLUSIONS: The photosynthetic capacity of C. procera was higher than that of C. gigantea. During the DS, A was regulated by stomatal and non-stomatal factors in a coordinated manner and drought did not cause chronic photoinhibition. A higher density of trichomes and leaf angle in C. gigantea may contribute to the maintenance of A and confer more efficient protection of photochemical activity in the DS. Ecophysiological traits such as high photosynthetic rate throughout the year even during the DS, and high WUE, highly pubescent leaves and low SLA observed in both species contribute to the establishment and growth of Calotropis in dry conditions.

Stomatal and non-stomatal limitations of photosynthesis in trees of a tropical seasonally flooded forest.

Trees in the flooded forest of the Mapire River in Venezuela suffer a decrease in photosynthetic rate (A) when flood begins, which is reverted at maximum flood. Changes in A are accompanied by similar changes in stomatal conductance (g(s)), and the possibility of changes in photosynthetic capacity is not ruled out. In order to understand how relative stomatal and non-stomatal limitations of photosynthesis are affected by flooding, we studied the seasonal changes in A and its response to intercellular CO(2) concentration in trees of Campsiandra laurifolia, Symmeria paniculata, Acosmium nitens and Eschweilera tenuifolia. Flooding caused in trees of C. laurifolia and S. paniculata a reduction in A, g(s), carboxylation efficiency and total soluble protein (TSP), whereas gas exchange in A. nitens and E. tenuifolia was more sensitive to drought. Under flooding, relative stomatal limitation (L(s)) was on average half the highest, and relative non-stomatal limitation (L(ns)) increased from the dry season to flooding. Under full flood, A, g(s) and TSP regained high values. A was positively correlated to light-saturated electron transport rate, suggesting that part of the decrease in A under flooding was due to impairment of photosynthetic capacity. Under flooding, not only stomatal closure but also increased L(ns) causes a reduction in photosynthesis of all four species, and a process of acclimation as flooding progresses allows gas exchange and related variables to regain high values.

Relaciones hídricas, fotosíntesis, y anatomía foliar de dos especies del género Calotropis / Water relations, photosynthesis, and leaf anatomy in two species of Calotropis genus

El género Calotropis es originario de Asia y es considerado una maleza de zonas áridas. En Venezuela el género esta representado por dos especies arbustivas, C. procera y C. gigantea, que se encuentran en hábitats xerofíticos y se caracterizan por ser muy resistentes a la sequía. Para conocer y comparar las características ecofisiológicas de estas especies, se realizó un estudio en el Litoral Central donde se evaluó el estado hídrico, el intercambio gaseoso y la anatomía foliar de ambas especies durante las temporadas de lluvia y de sequía. No se observaron diferencias significativas en el estado hídrico entre ambas especies, aunque la sequía causó una reducción del 50 por ciento en su potencial hídrico. Las mayores tasas de fotosíntesis (A) y conductancia estomática (gs) fueron observadas en lluvia en ambas especies, siendo 40 y 48 por ciento más altas en C. procera que en C. gigantea. La gs fue 41 por ciento mayor en lluvia que en sequía en C. procera, mientras que en C. gigantea no varió. C. procera presentó una mayor eficiencia de uso de agua (EUA). Las hojas de ambas especies mostraron una estructura mesofilar isolateral y anfiestomáticas, con alta pubescencia, observándose diferencias significativas en el grosor foliar y en el área foliar específica. Los resultados muestran que la capacidad fotosintética de C. procera fue mayor que la observada en C. gigantea.

Seasonal changes in water relations photosynthesis and leaf anatomy of two species growing along a natural CO2 gradient

Se realizaron medidas del estado hídrico, intercambio gaseoso y características anatómicas foliares en dos especies (Brownea coccinea y Spatiphylum cannifolium) que crecen naturalmente a lo largo de un gradiente natural de CO2, desde una concentración supra-atmosférica (CS) de 35000µmol.mol-¹ a una concentración ambiental (CA) de 435µmol-mol-¹, en el bosque ribereño del río Santa Ana (estado Sucre, Venezuela). Las medidas se realizaron en dos épocas contrastes, lluvia y sequía. El potencial hídrico (psy) fue cerca de 60 por ciento mayor en lluvia que en sequía en ambas especies. El crecimiento en CS no ocasionó cambios en el (psi) de B. coccinea, mientras que en S. cannifolium causó un descenso, estos cambios estuvieron acompañados en ambas especies con disminuciones en el potencial osmótico (psi pi). Las elevadas concentraciones de CO2 causaron una mejora en la fotosíntesis (A) y la conductancia estomática (gs) de B. coccinea, pero en S. cannifolium no se encontraron diferencias significativas. En las plantas de ambas especies que crecen en CS las hojas eran 10 por ciento más gruesas debido a un incremento del grosor de los tejidos del mesófilo en la misma proporción; además, las plantas de S. cannifolium que crecen en CS tiene lugar una mayor deposición de ceras espicuticulares durante la época de sequía