Evaluation of the genotoxic potential of Austroplenckia populnea (Reiss) Lundell chloroform fraction from barkwood extract in rodent cells in vivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antiulcerogenic and analgesic effects of the Austroplenckia populnea extracts in mice

Austroplenckia populnea (Reiss.) Lund. is a Brazilian Cerrado plant belonging to the Celastraceae family. Hexane and methanol extracts of leaves were investigated for their antiulcerogenic (ethanol and indomethacin/bethanecol induced gastric damage) and analgesic (writhing and tail-flick tests) activities in mice. Acute toxic effects also were evaluated. Oral administration of both extracts at a dose of 1000 mg/kg significantly reduced the total area of the lesion, the relative area of lesion and the ulcerative index in ethanol-induced gastric damage, but both extracts were inactive in the indomethacin/bethanecol-induced gastric damage test. A dose dependent effect was determined with the hexane extract in the ethanol-induced lesions test. The hexane and methanol extracts reduced the number of contortions in the writhing test, but both extracts were inactive in the tail-flick immersion test. Copyright (C) 2002 John Wiley Sons, Ltd.

Effects of the hydromethanolic extract of Austroplenckia populnea (Celastraceae) on reproductive parameters of male rats

Austroplenckia populnea (Reiss.) Lundell. was selected for this study because it has been shown that some plants from the Celastraceae family have antifertility effects. Twelve adult male rats were treated with hydromethanolic extract made from the leaves, 500 mg/kg/day, orally, for 70 days. Distilled water was administered to the control animals (n = 10). At the end of the experiment, and before killing the rats, their sexual behavior was evaluated. The number of intromissions, latencies to first mount and ejaculation, and first intromission after ejaculation were significantly reduced in the treated group, but the total number of ejaculations did not differ from the control group. The weight and histology of the reproductive organs, sperm production, spermatogenesis, prostate fructose content, cauda epidydimides duct diameter, and sperm morphology were not affected. Sperm concentration in cauda epidydimides was significantly decreased. The results showed that A. populnea has effects on male rat reproduction, affecting the sexual behavior and epididymal sperm concentration. (C) 2002 Elsevier B.V. All rights reserved.

Decrease in sperm number after treatment of rats with Austroplenckia populnea

The purpose of this study was to evaluate the effects of a hexanic extract (HE) made from leaves of A. populnea collected in Botucatu, State of São Paulo, and Nova Lima, State of Minas Gerais, Brazil, at a range of doses during 7 and 14 days, on the male reproductive system of rats. The treatment did not affect the body weight, nor absolute organ weight. The serum testosterone levels, testicular sperm head counts, daily sperm production, and sperm morphology did not differ from that of the control groups. The spermatogenesis and the morphometric parameters of cauda epididymidis were not affected by the treatment. Cauda epididymis sperm number was significantly reduced in the group that received HE of Nova Lima, 1 g/kg/day, during 14 days, from the control group. (C) 2000 Elsevier B.V. All rights reserved.

Constituintes químicos e atividade antiespermatogênica em folhas de Austroplenckia populnea (Celastraceae)

Folhas de Austroplenckia populnea (mangabarana, marmelinho do campo) foram submetidos a estudo fitoquímico. do extrato hexânico foram isolados e identificados três triterpenos pentacíclicos e um sesquiterpeno agarofurânico inédito. Realizou-se testes de atividade antiespermatogência utilizando parte deste extrato. Os resultados mostraram uma redução significativa do número de espermatozóides no epidídimo.

In vivo clastogenicity assessment of the Austroplenckia populnea (Celastraceae) leaves extract using micronucleus and chromosome aberration assay

The clastogenic effect of the A. populnea leaves extract was tested in vivo on bone marrow cells of Wistar rats by evaluating the induction of chromosome aberrations and micronuclei induction on polychromatic erythrocytes. The extract was administered by gavage at doses of 300, 600 and 900mg/kg body weight. Experimental and control animals were submitted to euthanasia 24 h after the treatment. Under the conditions used, A. populnea leaves extract did not induce decrease in mitotic index and did not induce a statistically significant increase in the mean number of micronucleated polychromatic erythrocytes or chromosome aberrations in the bone marrow cells of Wistar rats. © 2007 The Japan Mendel Society.

Woody plant responses to various clearing strategies imposed on a poplar box (Eucalyptus populnea) community at Dingo in central Queensland

The efficacy of individual tree treatment (stem-injection), aerially applied root-absorbed herbicide and mechanical felling (with and without subsequent fire) in controlling woody plants was compared in a poplar box (Eucalyptus populnea) woodland community in central Queensland, Australia. All treatments reduced woody plant populations and basal area relative to the untreated control. Chemical control and 'mechanical felling plus fire' treatments were equally effective in reducing woody plant basal area 7 years after the treatments were imposed. However, mechanical felling alone was less effective. There was a clear tendency for the scattered tree (80% thinning) treatment to recover woody plant basal area towards pre-treatment levels faster than other clearing strategies, although this response was not significantly different from 20% clump retention and mechanical felling (without burning) treatments.

Research note: poplar box (Eucalyptus populnea) growth rates in thinned and intact woodlands in central Queensland

A 19-year data set, which highlights the rapid growth rate in basal area of trees in thinned plots compared with unthinned controls, is presented. These results support the contention that, following tree thinning, basal area of retained trees will increase more rapidly than that of trees on unthinned areas. Indications are that pre-thinning levels in tree basal area will again be reached before the cost of treatment can be recouped by increased pasture and livestock production.

Die Brutpflege des Espenbockkäfers (Seperda populnea L.)

Von Ludwig Benick

Die Brutpflege des Espenbockkäfers (Saperda populnea L.) : Schluß

Von Ludwig Benick

Effect of NaCl on emergence and growth of a range of provenances of Eucalyptus citriodora, Eucalyptus populnea, Eucalyptus camaldulensis and Acacia salicina

High salt levels in mine spoils have been identified as one of the major chemical limitations to plant establishment after coal mining in central Queensland. Soil solution extracts from spoils indicated that EC levels of up to 26 dS/m could be encountered. Glasshouse trials examined the emergence and growth of Eucalyptus citriodora, Eucalyptus camaldulensis and Eucalyptus populnea provenances and Acacia salicina subjected to such EC levels. Relatively low levels of salt (100 mM NaCl, or 11 dS/m) with respect to the levels encountered on mine spoils, were enough to substantially reduce the rate and percentage emergence of all eucalypt provenances. A. salicina was found to be superior to the eucalypts in its ability to emerge and survive under saline conditions. It was the only species to have seedlings emerge and survive at 200 mM NaCl (20 dS/m), and the effect of salt on decreasing seedling dry weight was less pronounced for A. salicina than for any of the eucalypts. Established plants survived the range of salt treatments far better than emerging seedlings, with survival of established plants being reduced only at 300 and 400 mM NaCl (28 and 36 dS/m, respectively). A. salicina performed significantly better at 300 and 400 mM NaCl than most of the eucalypts studied. (c) 2006 Elsevier B.V. All rights reserved.

Buffel grass in Queensland's semi-arid woodlands: response to local and landscape scale variables, and relationship with grass, forb and reptile species.

Buffel grass [Pennisetum ciliare (L.) Link] has been widely introduced in the Australian rangelands as a consequence of its value for productive grazing, but tends to competitively establish in non-target areas such as remnant vegetation. In this study, we examined the influence landscape-scale and local-scale variables had upon the distribution of buffel grass in remnant poplar box (Eucalyptus populnea F. Muell.) dominant woodland fragments in the Brigalow Bioregion, Queensland. Buffel grass and variables thought to influence its distribution in the region were measured at 60 sites, which were selected based on the amount of native woodland retained in the landscape and patch size. An information-theoretic modelling approach and hierarchical partitioning revealed that the most influential variable was the percent of retained vegetation within a 1-km spatial extent. From this, we identified a critical threshold of similar to 30% retained vegetation in the landscape, above which the model predicted buffel grass was not likely to occur in a woodland fragment. Other explanatory variables in the model were site based, and included litter cover and long-term rainfall. Given the paucity of information on the effect of buffel grass upon biodiversity values, we undertook exploratory analyses to determine whether buffel grass cover influenced the distribution of grass, forb and reptile species. We detected some trends; hierarchical partitioning revealed that buffel grass cover was the most important explanatory variable describing habitat preferences of four reptile species. However, establishing causal links - particularly between native grass and forb species and buffel grass - was problematic owing to possible confounding with grazing pressure. We conclude with a set of management recommendations aimed at reducing the spread of buffel grass into remnant woodlands.

Landscape structure influences tree density patterns in fragmented woodlands in semi-arid eastern Australia.

Landscape and local-scale influences are important drivers of plant community structure. However, their relative contribution and the degree to which they interact remain unclear. We quantified the extent to which landscape structure, within-patch habitat and their confounding effects determine post-clearing tree densities and composition in agricultural landscapes in eastern subtropical Australia. Landscape structure (incorporating habitat fragmentation and loss) and within-patch (site) features were quantified for 60 remnant patches of Eucalyptus populnea (Myrtaceae) woodland. Tree density and species for three ecological maturity classes (regeneration, early maturity, late maturity) and local site features were assessed in one 100 × 10 m plot per patch. All but one landscape characteristic was determined within a 1.3-km radius of plots; Euclidean nearest neighbour distance was measured inside a 5-km radius. Variation in tree density and composition for each maturity class was partitioned into independent landscape, independent site and joint effects of landscape and site features using redundancy analysis. Independent site effects explained more variation in regeneration density and composition than pure landscape effects; significant predictors were the proportion of early and late maturity trees at a site, rainfall and the associated interaction. Conversely, landscape structure explained greater variation in early and late maturity tree density and composition than site predictors. Area of remnant native vegetation within a landscape and patch characteristics (area, shape, edge contrast) were significant predictors of early maturity tree density. However, 31% of the explained variation in early mature tree differences represented confounding influences of landscape and local variables. We suggest that within-patch characteristics are important in influencing semi-arid woodland tree regeneration. However, independent and confounding effects of landscape structure resulting from previous vegetation clearing may have exerted a greater historical influence on older cohorts and should be accounted for when examining woodland dynamics across a broader range of environments.

Floristic composition and pasture condition of Aristida/Bothriochloa pastures in central Queensland. I. Pasture floristics

A survey was conducted in central inland Queensland, Australia of 108 sites that were deemed to contain Aristida/Bothriochloa native pastures to quantitatively describe the pastures and attempt to delineate possible sub-types. The pastures were described in terms of their floristic composition, plant density and crown cover. There were generally ~20 (range 5–33) main pasture species at a site. A single dominant perennial grass was rare with three to six prominent species the norm. Chrysopogon fallax (golden-beard grass) was the perennial grass most consistently found in all pastures whereas Aristida calycina (dark wiregrass), Enneapogon spp. (bottlewasher grasses), Brunoniella australis (blue trumpet) and Panicum effusum (hairy panic) were all regularly present. The pastures did not readily separate into broad floristic sub-groups, but three groups that landholders could recognise from a combination of the dominant tree and soil type were identified. The three groups were Eucalyptus crebra (narrow-leaved ironbark), E. melanophloia (silver-leaved ironbark) and E. populnea (poplar box). The pastures of the three main sub-groups were then characterised by the prominent presence, singly or in combination, of Bothriochloa ewartiana (desert bluegrass), Eremochloa bimaculata (poverty grass), Bothriochloa decipiens (pitted bluegrass) or Heteropogon contortus (black speargrass). The poplar box group had the greatest diversity of prominent grasses whereas the narrow-leaved ironbark group had the least. Non-native Cenchrus ciliaris (buffel grass) and Melinis repens (red Natal grass) were generally present at low densities. Describing pastures in terms of frequency of a few species or species groups sometimes failed to capture the true nature of the pasture but plant abundance for most species, as density, herbage mass of dry matter or plant crown cover, was correlated with its recorded frequency. A quantitative description of an average pasture in fair condition is provided but it was not possible to explain why some species often occur together or fail to co-exist in Aristida/Bothriochloa pastures, for example C. ciliaris and E. bimaculata rarely co-exist whereas Tragus australianus (small burrgrass) and Enneapogon spp. are frequently recorded together. Most crown cover was provided by perennial grasses but many of these are Aristida spp. (wiregrasses) and not regarded as useful forage for livestock. No new or improved categorisation of the great variation evident in the Aristida/Bothriochloa native pasture type can be given despite the much improved detail provided of the floristic composition by this survey.