Mariza Barion Romagnolo

Structure, composition and spatial distribution of tree species in a remnant of the semideciduous seasonal Alluvial Forest of the upper Paraná River Floodplain

The aim of this investigation was to study the structure, distribution patterns, and dynamics of tree species in a remnant of the Semideciduous Seasonal Alluvial Forest in the Upper Parana River Floodplain, Brazil. Spatial variation of the vegetation was considered mainly in relation to soil and topographic characteristics. The 5,946 m2 study area extended along a transect from the bank of the Parana River across the floodplain, passing through a lake. Phytosociological analysis were performed for 36 plots, each 150 m2. Subanalysis were performed for 300 m2 zones. Soil characteristics and topographic profile and their relationship to the vegetation were analyzed. Hydrodynamic and sediment processes were the most important factors in vegetation establishment and succession, determining species selection and formation and evolution of the substrate. These processes and their local spatial variability fundamentally affected the dynamics, structure, and patterns of distribution.

Antileishmanial and antioxidant potential of fractions and isolated compounds from Nectandra cuspidata

Abstract The effects on the viability of promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and citotoxicity in J774.A1 macrophages of ethanolic extract, fractions and isolated compounds that were obtained from the leaves of Nectandra cuspidata were determined. The total phenolics content (TP) and antioxidant activity were assessed using different assays. The ethyl acetate fraction (EAF) had the best antiproliferative activity (amastigote IC50: 4.42 ± 0.60 μg/mL, promastigote IC50: 33.33 ± 0.78) and presented no cytotoxicity at the highest concentration tested (1000 μg/mL). The EAF also had the greatest antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (DPPH IC50 6.54 ± 0.10 μg/mL, ABTS 4.75 ± 0.11 mmol ET/g; FRAP 2.37 ± 0.03 mmol ET/g; ORAC = 33.52 ± 1.99 mmol ET/g; TP 387.11 ± 0.25 mg GAE/g). Vitexin, epicatechin and isovitexin isolated from EAF contribute to both activities.

Meiotic behavior during microsporogenesis of Alchornea triplinervia (Sprengel) Müller Argoviensis

The Alchornea triplinervia specie belongs to the Euphorbiaceae family, one of the main families of the Brazilian flora. In order to contribute to a better understanding of the specie, a counting of chromosome number and the microsporogenesis analysis of A. triplinervia were done. The inflorescences were collected in the municipalities of Paranavai and Diamante do Norte, State of Parana, Brazil, and the slides were prepared by squashing technique and staining with 1% acetic carmine. The analysis were performed using an optical microscope and showed a chromosome number for the specie equal to 2n=8x=72. Irregularities in the chromosome segregation process were the main meiotic abnormalities, presenting typical polyploid behavior. Other irregularities were observed; however, at low frequency without compromising the pollen grain formation of the analyzed plants.

Complex of pollen mother cell and polyad production during microsporogenesis in Hippocratea volubilis (Hippocrateaceae)

Cytogenetic studies are a useful tool for the study of systematics and evolution in plants. The current paper reports on polyad production during microsporogenesis of Hippocratea volubilis. The analyzed material was collected in the Ecological Station of Caiuá in Diamante do Norte, PR, Brazil. The meiotic analysis was performed using a squashing technique and the stain was 1% acetic carmine. The chromosome segregation process during meiotic division was normal. However, pollen mother cells (PMCs) were bonded in fours or twos, through cytoplasmic channels during the whole microsporogenesis. After telophase II, four-PMC complexes produced tetra-tetrads with 16 microspores, whereas two-PMC complexes produced bi-tetrads with eight microspores. Microspores formed in the process remained bonded and formed polyads with 16 or eight pollen grains.

Germination responses of four pioneer plant species after passage through the gut of a frugivorous Neotropical bat

ABSTRACT Seed passage through the guts of bats potentially influences germination in different ways: physically, chemically and biologically. To evaluate the influence of a Neotropical bat on the seed germination of four pioneer plant species, an experiment was conducted. Considering the positive influence of bats on germination and the possibility of observing non-viability caused by microorganisms, we hypothesized that (i) seeds subjected to passage through bat guts without the influence of microorganisms have a higher germination potential. Considering the different ecological requirements for the germination of plant species, we also hypothesized that (ii) the four plant species present different germination parameters. The germination of seeds from feces and fruits in the presence and absence of microorganisms was compared for each plant species and among the four plant species. The ingestion of seeds by bats and the presence of microorganisms either improved or did not influence the germination parameters of plants, but the direction of the effects did not support the hypothesis in all cases. The germination parameters differed among most plant species except between Ficus adhatodifolia and F. guaranitica. Our findings indicate that the influence of bats on seeds depends on the microorganisms and singularities of plant species.

Photodamage attenuating potential of Nectandra hihua against UVB-induced oxidative stress in L929 fibroblasts

The total phenolic content (TP) and antioxidant activity of the ethanolic extract and fractions that were obtained from the leaves of Nectandra hihua were assessed using different methods. The ethanolic extract (EE) and ethyl acetate fraction (EAF) had the best antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (ABTS+ 2.55 ± 0.06, 3.54 ± 0.03 mmol TE/g; DPPH IC50 10.27 ± 0.05, 9.88 ± 0.02 μg/mL; FRAP 2.17 ± 0.08, 2.38 ± 0.04 mmol TE/g; ORAC 5.16 ± 0.08, 5.35 ± 0.07 mmol TE/g; TP 568.05 ± 18.15, 397.20 ± 17.88 mg GAE/g, respectively). The cytoprotective effect, reactive oxygen species (ROS) and lipid peroxidation inhibitions on L929 fibroblasts irradiated with UVB (600 mJ/cm2) in pre- and post-treatments with EE and EAF were determined. These plant materials demonstrated high ROS scavenging activity and lipid peroxidation inhibition on L929 fibroblasts in both treatments, especially with pre-treatment (EE 38.47 ± 1.95% and EAF 40.20 ± 4.5% inhibition of ROS production, and EE 39.03 ± 3.33% and EAF 41.67 ± 7.6% of lipid peroxidation inhibition), indicating the best cytoprotection with pre-treatment (13.52 ± 1.66% and 13.34 ± 2.61% increases in cell viability). The antioxidant flavonoids quercitrin, avicularin, juglalin, afzelin and astragalin were isolated from EAF. The results obtained indicate that EE and EAF present photodamage attenuating potential against UVB-induced oxidative stress and can be useful as a starting point for developing dermatological products to prevent oxidative skin damage.