Antioxidant activity of Haloxylon scoparium alkaloid extracts from Figuig region (southeastern of Morocco)

Abstract The aim of this paper is to study the chemical composition of alkaloids present in Haloxylon scoparium Pomel extracts and to evaluate their antioxidant capacity. The alkaloids were isolated from two parts of Haloxylon scoparium plant by two extraction protocols. and The quantitative study made it possible to propose the best protocol for the extraction of the alkaloids. Moreover, GC-MS analysis of alkaloid extracts allowed us to determine their chemical composition. Haloxylon scoparium contains four types of alkaloids: tetraisoquinolines, phenylethylamines, tryptolines and tryptamines. The main compounds are the tetraisoquinolines type, the predominant product of which was N-methylsalsoline. These compounds present a great interest for the researchers due to their various pharmacological and biological activities. The antioxidant effect of the different plant extracts was studied by two methods: the ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl hydrazyl free radical (DPPH·) scavenging tests. The results show that extracts of root part are more active than those from aerial part; the acetone/water extract is the most powerful. The interesting results obtained in this study will be supplemented by other analyses and biological tests in order to better valorize this plant.

Production of pigments in Alternanthera sessilis calli mediated by plant growth regulators and light / Produção de pigmentos em calos de Alternanthera sessilis mediados por reguladores de crescimento e luz

Among the compounds produced by plants, pigments such as betalains have received attention from both food and pharmaceuticals industries. The Alternanthera sessilis species produces these pigments, though in small quantities, and so it is necessary to increase production. Thus, many studies use elicitors that are capable of triggering physiological or morphological responses in plants. The objective was to establish callus production in A. sessilis grown under different combinations of growth regulators and light qualities and to assess whether these factors can increase betalain and flavonoid production. Leaf and internodal explants in MS medium with different growth regulators were used to obtain calli, which were subsequently transferred to a betacyanin induction medium remaining for 40 days under different light qualities (white, blue, red, and dark). The most suitable treatment for callus formation and subsequent betalain and flavonoid induction was to combine a medium containing 6.7 µmol L-1 2,4-D and 9.0 µmol L-1 BAP and blue light. Physical elicitation by light combined with appropriate concentration of growth regulators on calli can increase production of commercially important metabolites.(AU) 

Dentre os compostos produzidos pelas plantas, os pigmentos, como as betalaínas, vêm recebendo destaque tanto pela indústria alimentícia como farmacêutica. A espécie Alternanthera sessilis produz esses pigmentos, porém em pequenas quantidades, sendo necessário incrementar a produção. Para isso, muitos estudos utilizam elicitores que são capazes de desencadear respostas fisiológicas ou morfológicas nas plantas. O objetivo do trabalho foi estabelecer a produção de calos de A. sessilis crescidos quando submetidos a diferentes combinações de reguladores de crescimento e qualidades de luz, e avaliar se esses fatores são capazes de incrementar a produção de betalaínas e flavonoides. Foram utilizados explantes foliares e internodais em meio MS com diferentes reguladores de crescimento para obtenção dos calos que, posteriormente, foram transferidos para meio de indução de betacianina, onde permaneceram por 30 dias sob diferentes qualidades de luz (branca, azul, vermelha e escuro). O tratamento mais propício para formação de calos e consequente indução de betalaínas e flavonoides foi a combinação do meio contendo 6,7 μmol L-1 2,4-D e 9,0 μmol L-1 BAP e a luz azul. Conclui-se que a elicitação física pela luz em conjunto com a concentração adequada de reguladores de crescimento em calos é capaz de incrementar a produção de metabólitos de interesse comercial.(AU)

Compartmentalization and ultrastructural alterations induced by chromium in aquatic macrophytes.

The aim of the present study was to identify the sites of accumulation of Cr in the species of macrophytes that are abundant in the Cachoeira river, namely, Alternanthera philoxeroides, Borreria scabiosoides, Polygonum ferrugineum and Eichhornia crassipes. Plants were grown in nutritive solution supplemented with 0.25 and 50 mg l(-1) of CrCl(3)·6H(2)O. Samples of plant tissues were digested with HNO(3)/HCl in a closed-vessel microwave system and the concentrations of Cr determined using inductively-coupled plasma mass spectrometry (ICP-MS). The ultrastructure of root, stem and leaf tissue was examined using transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) in order to determine the sites of accumulation of Cr and to detect possible alterations in cell organelles induced by the presence of the metal. Chromium accumulated principally in the roots of the four macrophytes (8.6-30 mg kg(-1) dw), with much lower concentrations present in the stems and leaves (3.8-8.6 and 0.01-9.0 mg kg(-1) dw, respectively). Within root tissue, Cr was present mainly in the vacuoles of parenchyma cells and cell walls of xylem and parenchyma. Alterations in the shape of the chloroplasts and nuclei were detected in A. philoxeroides and B. scabiosoides, suggesting a possible application of these aquatic plants as biomarkers from Cr contamination.

Leaf surfaces of Gomphrena spp. (Amaranthaceae) from Cerrado biome.

The leaf structure and micromorphology characterize plant species and reflex its interactions with the environment. Leaf epidermis sculptures aid high transpiration plants on light reflection. The form and distribution of epicuticular wax crystalloids are important to characterize the surface. Aiming to know the micromorphology and the ultrastructure of G. arborescens, G. pohlii and G. virgata, leaves of these Cerrado native species were collected in Brasília, Distrito Federal, Brazil, at the Olympic Center of the Universidade de Brasília and at Reserva Ecológica do Roncador. Leaves of G. globosa, an Indian native species, were also studied for comparison. Leaves were fractionated, fixed and treated for observation under optical and scanning electron microscope. A description of the leaf epidermis is provided, along with some quantitative data to help the species taxonomy and support future studies on their physiology: all species are amphistomatic and have Stomatal Index between 7.27 and 18.99. The Gomphrena spp. studied have epicuticular wax platelets and wax sculptures over their larger trichome, which are relevant for their taxonomy. Over the Cerrado species cuticle, epicuticular wax is damaged by fungi hyphae development. The presence of epicuticular wax on Gomphrena spp. leaves corroborates the phylogenetical alliance between Amaranthaceae and Chenopodiaceae.

Leaf surfaces of Gomphrena spp. (Amaranthaceae) from Cerrado biome

The leaf structure and micromorphology characterize plant species and reflex its interactions with the environment. Leaf epidermis sculptures aid high transpiration plants on light reflection. The form and distribution of epicuticular wax crystalloids are important to characterize the surface. Aiming to know the micromorphology and the ultrastructure of G. arborescens, G. pohlii and G. virgata, leaves of these Cerrado native species were collected in Brasília, Distrito Federal, Brazil, at the Olympic Center of the Universidade de Brasília and at Reserva Ecológica do Roncador. Leaves of G. globosa, an Indian native species, were also studied for comparison. Leaves were fractionated, fixed and treated for observation under optical and scanning electron microscope. A description of the leaf epidermis is provided, alo ng with some quantitative data to help the species taxonomy and support future studies on their physiology: all species are amphistomatic and have Stomatal Index between 7.27 and 18.99. The Gomphrena spp. studied have epicuticular wax platelets and wax sculptures over their larger trichome, which are relevant for their taxonomy. Over the Cerrado species cuticle, epicuticular wax is damaged by fungi hyphae development. The presence of epicuticular wax on Gomphrena spp. leaves corroborates the phylogenetical alliance between Amaranthaceae and Chenopodiaceae.

Leaf surfaces of Gomphrena spp. (Amaranthaceae) from Cerrado biome

The leaf structure and micromorphology characterize plant species and reflex its interactions with the environment. Leaf epidermis sculptures aid high transpiration plants on light reflection. The form and distribution of epicuticular wax crystalloids are important to characterize the surface. Aiming to know the micromorphology and the ultrastructure of G. arborescens, G. pohlii and G. virgata, leaves of these Cerrado native species were collected in Brasília, Distrito Federal, Brazil, at the Olympic Center of the Universidade de Brasília and at Reserva Ecológica do Roncador. Leaves of G. globosa, an Indian native species, were also studied for comparison. Leaves were fractionated, fixed and treated for observation under optical and scanning electron microscope. A description of the leaf epidermis is provided, alo ng with some quantitative data to help the species taxonomy and support future studies on their physiology: all species are amphistomatic and have Stomatal Index between 7.27 and 18.99. The Gomphrena spp. studied have epicuticular wax platelets and wax sculptures over their larger trichome, which are relevant for their taxonomy. Over the Cerrado species cuticle, epicuticular wax is damaged by fungi hyphae development. The presence of epicuticular wax on Gomphrena spp. leaves corroborates the phylogenetical alliance between Amaranthaceae and Chenopodiaceae.(AU)

Antioxidant system activation by mercury in Pfaffia glomerata plantlets.

Oxidative stress caused by mercury (Hg) was investigated in Pfaffia glomerata plantlets grown in nutrient solution using sand as substrate. Thirty-day-old acclimated plants were treated for 9 days with four Hg levels (0, 1, 25 and 50 microM) in the substrate. Parameters such as growth, tissue Hg concentration, toxicity indicators (delta-aminolevulinic acid dehidratase, delta-ALA-D, activity), oxidative damage markers (TBARS, lipid peroxidation, and H(2)O(2) concentration) and enzymatic (superoxide dismutase, SOD, catalase, CAT, and ascorbate peroxidase, APX) and non-enzymatic (non-protein thiols, NPSH, ascorbic acid, AsA, and proline concentration) antioxidants were investigated. Tissue Hg concentration increased with Hg levels. Root and shoot fresh weight and delta-ALA-D activity were significantly decreased at 50 microM Hg, and chlorophyll and carotenoid concentration were not affected. Shoot H(2)O(2) concentration increased curvilinearly with Hg levels, whereas lipid peroxidation increased at 25 and 50 microM Hg, respectively, in roots and shoots. SOD activity showed a straight correlation with H(2)O(2) concentration, whereas CAT activity increased only in shoots at 1 and 50 microM Hg. Shoot APX activity was either decreased at 1 microM Hg or increased at 50 lM Hg. Conversely, root APX activity was only increased at 1 microM Hg. In general, AsA, NPSH and proline concentrations increased upon addition of Hg, with the exception of proline in roots, which decreased. These changes in enzymatic and non-enzymatic antioxidants had a significant protective effect on P. glomerata plantlets under mild Hg-stressed conditions.