Evaluation of the anti-inflammatory, antipyretic and antinociceptive activities of the hydroalcoholic extract of Rhynchospora nervosa (Vahl) Boeckeler (Cyperaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Rhynchospora nervosa (Vahl) Boeckeler (Cyperaceae), popularly known as "capim-estrela", is a native species widely distributed in Brazil. The whole plant has been used in local traditional medicine in the form of teas or syrups to treat inflammation, flu, nasal congestion, fever, swelling, and venereal disease. This is the first study to investigate the pharmacological properties of this species.

AIM OF THE STUDY

The present study aimed to evaluate the in vivo anti-inflammatory, antipyretic and antinociceptive potential of the lyophilized hydroalcoholic extract of R. nervosa in heterogenic Swiss mice. In addition to pharmacological studies, the total phenol and flavonoid contents of the extract were determined.

MATERIAL AND METHODS

The anti-inflammatory effect was evaluated through carrageenan-induced paw edema and peritonitis models. For the antinociceptive assay, the number of acetic acid-induced writhing responses in the animals was counted. Antipyretic activity was tested by yeast-induced pyrexia in mice and evaluated for 4 h. Nitric oxide (NO) concentration and leukocyte migration in the peritoneal fluid were quantified. The acute toxicity of the extract was also calculated. Quantitative analyses of total phenols and flavonoids in the extract were performed by spectrophotometric methods.

RESULTS

In short, the lyophilized hydroalcoholic extract of R. nervosa showed low acute toxicity in the preclinical tests (LD₅₀ = 3807 mg/kg). A significant anti-inflammatory effect was observed, with an average reduction of carrageenan-induced paw edema of 96.37%. Comparatively, indomethacin inhibited the development of the carrageenin paw edema by 97.52%. In the peritonitis test, a significant reduction in NO levels was recorded. A reduction in the number of white cells, notably monocytes, was also observed, confirming the anti-inflammatory effect. Writhing was reduced by 86.53%, which indicates antinociceptive activity. As for antipyretic activity, no positive effects of the extract were observed. The lyophilized hydroalcoholic extract of R. nervosa presented a high content of phenolic compounds (322.47 μg GAE/mg) and total flavonoids (440.50 μg QE/mg).

CONCLUSION

The lyophilized hydroalcoholic extract of R. nervosa showed significant in vivo anti-inflammatory and antinociceptive activity in mice. These preliminary findings support the indication of the use of this species in folk medicine in Brazil for the treatment of inflammation.

The relief effects of organic acids on Scirpus triqueter L. under pyrene-lead stress

During phytoremediation of polycyclic aromatic hydrocarbons (PAHs) and heavy metals, the phytoremediation plants are often stressed by pollutants, which would reduce the efficiency of phytoremediation. The addition of organic acids from root exudates could alleviate the stress. In this study, three organic acids (citric acid, succinic acid, glutaric acid) were added to investigate the effects of organic acids on the stress response of Scirpus triqueter L. at two pyrene-lead concentrations. The activities of reactive oxygen species, malondialdehyde, plasma membrane H⁺-ATPase, and vacuolar H⁺-ATPase and PPase activity, as well as the activities of antioxidant enzymes (SOD, POD, and CAT) in Scirpus triqueter L. were determined. The addition of organic acids could effectively reduce the activities of reactive oxygen species, malondialdehyde, plasma membrane H⁺-ATPase, and vacuolar H⁺-ATPase and PPase activities. Under higher pollution, the damage of plant plasma membrane is more serious, but the addition of citric acid can alleviate this situation and even more effective than the relief under low pollution. The effect of citric acid was more significant than that of succinic acid and glutaric acid. These results demonstrated that organic acids could attenuate the stress of pyrene and lead to Scirpus triqueter L.

Increased accumulation of Pb and Cd from contaminated soil with Scirpus triqueter by the combined application of NTA and APG

Phytoremediation of heavy metals contaminated soils shows many advantages and it can be improved by adding chelating agents and surfactants. In this study, pot culture experiments were set up to explore the effect of alone application of nitrilotriacetic acid (NTA) and combined application of NTA and alkyl polyglucoside (APG) on changes in absorption and adsorption of heavy metals by root of Scirpus triqueter and bioaccumulation of metals in single or co-contamination. Different additives were added into the soils artificially after 10 d and heavy metals extracted from different plant tissues were analyzed after 60 d. Results showed that more cadmium (Cd) was adsorbed on the root surface while more lead (Pb) was absorbed in root interior with the combined application of NTA and APG during phytoremediation of single contaminated soil. In co-contaminated soils, such a combined application not only strengthened the plant growth, but also promoted accumulation of Pb and Cd by Scirpus triqueter. NTA improved absorption amounts of Pb (9.7-fold) and Cd (1.0-fold) in root interior significantly. APG induced more metals to gather on the root surface in the presence of NTA and the adsorption amounts of Pb and Cd ranged from 26.2 and 17.7 mg kg^-1 to 412 and 46.0 mg kg^-1 respectively. Besides, the coexistence metal increased bioaccumulation of another metal under combined application of NTA and APG in co-contamination of Pb and Cd. In conclusion, the combined application of NTA and APG would be beneficial to accumulate Pb and Cd from contaminated soils by Scirpus triqueter.

Cyperaceae Species Are Potential Sources of Natural Mammalian Arginase Inhibitors with Positive Effects on Vascular Function

The inhibition of arginase is of substantial interest for the treatment of various diseases of public health interest including cardiovascular diseases. Using an ex vivo experiment on rat aortic rings and an in vitro assay with liver bovine purified arginase, it was demonstrated that several polyphenolic extracts from Cyperus and Carex species possess vasorelaxant properties and mammalian arginase inhibitory capacities. Phytochemical studies performed on these species led to the identification of eight compounds, including monomers, dimers, trimers, and tetramers of resveratrol. The potential of these stilbenes as inhibitors of mammalian arginase was assessed. Five compounds, scirpusin B (5), ε-viniferin (4), cyperusphenol B (6), carexinol A (7), and the new compound virgatanol (1), showed significant inhibition of arginase, with percentage inhibition ranging from 70% to 95% at 100 μg/mL and IC₅₀ values between 12.2 and 182.1 μM, confirming that these stilbenes may be useful for the development of new pharmaceutical products.

Assessment of Pb and pyrene accumulation in Scirpus triqueter assisted by combined alkyl polyglucoside and nitrilotriacetic acid application

To understand the accumulation and uptake of polycyclic aromatic hydrocarbons (PAHs) and heavy metals by plants is an important part of the assessment of phytoremediation for PAHs and heavy metals co-contaminated soil. This study was an investigation of the accumulation and uptake of pyrene and lead (Pb) by Scirpus triqueter under the condition of alkyl polyglucoside (APG) and nitrilotriacetic acid (NTA) combined application. The results indicated that the accumulation of Pb by S. triqueter was significantly improved by NTA and APG addition into the soil. The pyrene accumulation in plant was also increased after application of APG when compared to the control treatment. However, the pyrene accumulation was decreased when APG was applied together with NTA. SEM and TEM images of root surface suggested that more Pb in the soil transferred to the plant by combined application of APG and NTA. More importantly, TEM images of xylem cells of S.triqueter root showed that permeability of cell membrane was improved by application of APG.

A sedge plant as the source of Kangaroo Island propolis rich in prenylated p-coumarate ester and stilbenes

Propolis samples from Kangaroo Island, South Australia, were investigated for chemical constituents using high-field nuclear magnetic resonance spectral profiling. A type of propolis was found containing a high proportion of prenylated hydroxystilbenes. Subsequently, the botanical origin of this type of propolis was identified using a beehive propolis depletion method and analysis of flora. Ligurian honey bees, Apis mellifera ligustica Spinola, were found to produce propolis from resin exuded by the Australian native sedge plant Lepidosperma sp. Montebello (Cyperaceae). The plants, commonly known as sword sedge, were found to have resin that matched with the propolis samples identified as the most abundant propolis type on the island containing C- and O-prenylated tetrahydroxystilbenes (pTHOS) in addition to a small amount of prenylated p-coumarate. The isolation of five pTHOS not previously characterized are reported: (E)-4-(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene, (E)-2,4-bis(3-methyl-2-buten-1-yl)-3,3',4',5-tetrahydroxystilbene, (E)-2-(3-methyl-2-buten-1-yl)-3-(3-methyl-2-butenyloxy)-3',4',5-trihydroxystilbene, (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,3',5,5'-tetrahydroxystilbene and (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene. A National Cancer Institute 60 human cell line anticancer screen of three of these compounds showed growth inhibitory activity. The large Australasian genus Lepidosperma is identified as a valuable resource for the isolation of substances with medicinal potential.

In vivo antitumor effect, induction of apoptosis and safety of Remirea maritima Aubl. (Cyperaceae) extracts

BACKGROUND

Remirea maritima has been widely used in the treatment of diarrhea, kidney disease, and high fever and for therapeutic purposes, such as an analgesic and anti-inflammatory. However, few scientific research studies on its medicinal properties have been reported.

PURPOSE

The present study aimed to investigate the anticancer potential of aqueous extract (AE), 40% hydroalcoholic extracts (40HA) and 70% (70HA) from R. maritima in experimental models and to identify its phytochemical compounds.

METHODS

The chemical composition of AE, 40HA and 70HA was assessed by HPLC-DAD and ESI-IT-MS/MS. In vitro activity was determined on cultured tumor cell, NCI-H385N (Broncho-alveolar carcinoma), OVCAR-8 (Ovarian carcinoma) and PC-3M (prostate carcinoma) by the MTT assay, and the in vivo antitumor activity was assessed in Sarcoma 180-bearing mice. Toxicological parameters were also evaluated as well as the humoral immune response.

RESULTS

Among the aqueous and hydroalcoholic extracts of R. maritima, only 40HA showed in vitro biological effect potential, presenting IC50 values of 27.08, 46.62 and >50µg/ml for OVCAR-8, NCI-H385M and PC-3M cells lines, respectively. Regarding chemical composition, a mixture of isovitexin-2''-O-β-D-glucopyranoside, vitexin-2''-O-β-D-glucopyranoside, luteolin-7-O-glucuronide and 1-O-(E)-caffeoyl-β-D-glucose were identified as the major phytochemical compounds of the extracts. In the in vivo study, the tumor inhibition rates were 57.16-62.57% at doses of 25mg/kg and 50mg/kg, respectively, and the tumor morphology presented increasing numbers of apoptotic cells. Additionally, 40HA also demonstrated significantly increased of OVA-specific total Ig.

CONCLUSIONS

40HA exhibited in vitro and in vivo anticancer properties without substantial toxicity that could be associated with its immunostimulating properties.

Chemical constituents from the tubers of Scirpus yagara and their anti-inflammatory activities

A new natural compound, dehydrophyllodulcin (1) was isolated from the tubers of Scirpus yagara, together with 11 known compounds. Among them, compounds 2, 5-8, and 10-12 were isolated from this plant for the first time. (1)H NMR, (13)C NMR, and 2D NMR data of compound 1 are first reported in this article, though it was synthesized in 1996. The structures of all compounds were determined by comprehensive analyses of their spectroscopic data and compared with literature information. Moreover, the anti-inflammatory effects of compounds 1, 3, 4, 6, and 9 against inflammatory cytokines production in Lipopolysaccharide - or Pam3csk4-stimulated macrophage RAW264.7 cells were evaluated by Enzyme-linked immunosorbent assay. And these compounds significantly inhibited the tumor necrosis factor (TNF)-α, interleukin (IL)-6 productions in RAW264.7 cells, with IC50 values less than 20 μM.

Insolubilization of Chestnut Shell Pigment for Cu(II) Adsorption from Water

Chestnut shell pigment (CSP) is melanin from an agricultural waste. It has potential as an adsorbent for wastewater treatment but cannot be used in its original state because of its solubility in water. We developed a new method to convert CSP to insolubilized chestnut shell pigment (ICSP) by heating, and the Cu(II) adsorption performance of ICSP was evaluated. The conversion was characterized, and the thermal treatment caused dehydration and loss of carboxyl groups and aliphatic structures in CSP. The kinetic adsorption behavior obeyed the pseudo-second-order rate law, and the equilibrium adsorption data were well described with both the Langmuir and the Freundlich isotherms. ICSP can be used as a renewable, readily-available, easily-producible, environmentally-friendly, inexpensive and effective adsorbent to remove heavy-metal from aquatic environments.

Isolation and Characterization of Sclerienone C from Scleria striatinux

Herein, we report the isolation and characterization of sclerienone C, a novel sesquiterpene isolated from the methylene chloride/methanol (1:1) extract of Scleria striatinux that we have deduced to have structure 1. This medicinal spice of Cameroon has been shown to display antimicrobial and antiplasmodial activities. The isolation and purification involved a combination of methods including silica gel column chromatography, Sephadex LH-20, and semi-prep HPLC separations. Structure elucidation was carried-out by means of spectroscopic analysis and comparison with previously isolated sesquiterpene derivatives from the plant.

Identification of Scirpus triqueter root exudates and the effects of organic acids on desorption and bioavailability of pyrene and lead in co-contaminated wetland soils

Root exudates (REs) of Scirpus triqueter were extracted from the rhizosphere soil in this study. The components in the REs were identified by GC-MS. Many organic acids, such as hexadecanoic acid, pentadecanoic acid, vanillic acid, octadecanoic acid, citric acid, succinic acid, glutaric acid, and so on, were found. Batch simulated experiments were conducted to evaluate the impacts of different organic acids, such as citric acid, artificial root exudates (ARE), succinic acid, and glutaric acid in REs of S. triqueter on desorption of pyrene (PYR) and lead (Pb) in co-contaminated wetland soils. The desorption amount of PYR and Pb increased with the rise in concentrations of organic acids in the range of 0-50 g·L(-1), within shaking time of 2-24 h. The desorption effects of PYR and Pb in soils with various organic acids treatments decreased in the following order: citric acid > ARE > succinic acid > glutaric acid. The desorption rate of PYR and Pb was higher in co-contaminated soil than in single pollution soil. The impacts of organic acids in REs of S. triqueter on bioavailability of PYR and Pb suggested that organic acids enhanced the bioavailability of PYR and Pb in wetland soil, and the bioavailability effects of organic acids generally followed the same order as that of desorption effects.

Phytoremediation of cadmium by the facultative halophyte plant Bolboschoenus maritimus (L.) Palla, at different salinities

The cadmium phytoremediation capacity of the halophyte plant Bolboschoenus maritimus (L.) Palla and the influence of water salinity were assessed in a greenhouse experiment, in order to better understand the bioremediation capacity of this plant. Three concentrations of cadmium (0, 50 and 100 μg l(-1)) and four salinity conditions (0, 5, 10 and 20) were chosen to evaluate the cadmium accumulation, in order to test these plants as a potential phytoremediation tool in brackish environments. The cadmium content in water and plants (underground organs, stems and leaves) was analysed with graphite furnace atomic absorption spectrometry. All the plants submitted to salinity 20 and in the three cadmium treatments died. The plants' survival was highest in the lowest salinities, where highest growth and biomasses were also obtained. The plants presented more cadmium content in the rhizomes, followed by stems and even less in leaves. The salt stress of the plants interfered with their cadmium accumulation capacity. The highest cadmium accumulation in the rhizomes occurred at salinity 0, while the salinities 0 and 5 were the most adequate for stems and leaves. The experiment pointed out that B. maritimus represents a good possible intervenient for cadmium bioremediation in freshwater and low salinity brackish water environments, but its use is limited in the habitats of higher salinity.

Redox-Active Profile Characterization of Remirea maritima Extracts and Its Cytotoxic Effect in Mouse Fibroblasts (L929) and Melanoma (B16F10) Cells

Remirea maritima is a tropical plant with a reticulated root system belonging to the family Cyperaceae, also known to have biologically active secondary metabolites. However, very few data on R. maritima’s biological actions are available and there are no reports regarding the redox-active profile of this plant. In this study, we examined the total phenolic content of Remirea maritima hydroalcoholic (RMHA) extracts, redox properties against different reactive species generated in vitro and their cytotoxic effect against fibroblasts (L929) and melanoma (B16F10) cells. Total reactive antioxidant potential index (TRAP) and total antioxidant reactivity (TAR) results revealed that RMHA at all concentrations tested showed significant antioxidant capacity. RMHA was also effective against hydroxyl radical formation, reduction of Fe³⁺ to Fe²⁺ and in scavenging nitric oxide (NO) radicals. In vitro, the level of lipid peroxidation was reduced by RMHA extract and the data showed significant oxidative damage protection. The RMHA cytotoxicity was evaluated by a neutral red assay in fibroblast (L929) and melanome (B16F10) cells. The obtained results showed that the RMHA (40 and 80 µg/mL, respectively) reduced 70% of the viable cells. In conclusion, this study represents the first report regarding the antioxidant and anti-proliferative potential of R. maritima against B16F10 melanoma cells.

Cd accumulation and subcellular distribution in two ecotypes of Kyllinga brevifolia Rottb as affected by Cd treatments

The Cadmium (Cd) accumulation capacity and subcellular distribution in the mining ecotype (ME) and non-mining ecotype (NME) of Kyllinga brevifolia Rottb were investigated in pot experiments. The results showed that average Cd contents in shoots of the two ecotypes of K. brevifolia were higher than those in roots, whereas Cd concentrations in roots were greater than those in shoots. Also, shoot Cd contents in NME of K. brevifolia were 1.65-45.45 times greater than those in ME when the plants were grown at 5, 25, 50, and 100 mg Cd kg(-1) soil. Moreover, Cd contents in the roots in NME were 1.75-45.45 times higher than those in ME. Subcellular distribution of Cd demonstrated that the majority of Cd in the two ecotypes of K. brevifolia was distributed in the cell walls and soluble fraction, and a small percentage of Cd existed in organelle fraction. In addition, proportions of Cd distributed in shoots and roots cell walls of NME were greater than those in ME. It could be assumed that compared with ME, NME of K. brevifolia has better Cd accumulation capacity, and the subcellular distribution of Cd might be one of the mechanisms to explain such phenomena.

Plant-beneficial elements status assessment in soil-plant system in the vicinity of a chemical industry complex: shedding light on forage grass safety issues

Human health is closely linked with soils via plants, grazers, or plant-based products. This study estimated plant-beneficial elements (macronutrients: K, P; secondary macronutrients: Ca, Mg; micronutrients: Mo, Mn, Na, Ni, Se) in both soils and shoots of two forage grass species (Eriophorum angustifolium and Lolium perenne) prevalent in the vicinity of a chemical industry complex (Estarreja, Portugal). Both soils and plants from the chemical industrial areas exhibited differential concentrations of the studied elements. In soils, the role of contamination was evidenced as insignificant in context of its impact on all the tested macro and secondary macronutrients except P, and micronutrients such as Mo and Ni. In forage grass plant shoots, the role of contamination was evidenced as insignificant in relation to its impact on all the tested macro and secondary macronutrients except K. Between the two forage grass plants, high Se-harboring L. perenne cannot be recommended for its use as animal feed.

Chemical composition, antinociceptive, anti-inflammatory and redox properties in vitro of the essential oil from Remirea maritima Aubl. (Cyperaceae)

BACKGROUND

The present study was carried out to evaluate antioxidant, antinociceptive and anti-inflammatory activities of essential oil from R. maritima (RMO) in experimental protocols.

METHODS

The essential oil from the roots and rhizomes of RMO were obtained by hydrodistillation using a Clevenger apparatus, and analyzed by gas chromatography/mass spectrometry (GC/MS). Here, we evaluated free radical scavenging activities and antioxidant potential of RMO using in vitro assays for scavenging activity against hydroxyl radicals, hydrogen peroxide, superoxide radicals, and nitric oxide. The total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) indexes and in vitro lipoperoxidation were also evaluated. The ability of RMO to prevent lipid peroxidation was measured by quantifying thiobarbituric acid-reactive substances (TBARS). NO radical generated at physiological pH was found to be inhibited by RMO, that showed scavenging effect upon SNP-induced NO production at all concentrations. Antinociceptive and anti-inflammatory properties were evaluated by acetic acid writhing reflex, Formalin-induced nociception and Carrageenan-induced edema test.

RESULTS

The majors compounds identified was remirol (43.2%), cyperene (13.8%), iso-evodionol (5.8%), cyperotundone (5.7%), caryophyllene oxide (4.9%), and rotundene (4.6%). At the TRAP assay, RMO concentration of 1 mg.mL(-1) showed anti-oxidant effects and at concentration of 1 and 10 ng.mL(-1) RMO showed pro-oxidant effect. RMO at 1 mg.mL(-1) also showed significant anti-oxidant capacity in TAR measurement. Concentrations of RMO from 1 ng.mL(-1) to 100 μg.mL(-1) enhanced the AAPH-induced lipoperoxidation. RMO reduced deoxyribose oxidative damage, induced by the Fenton reaction induction system, at concentrations from 1 ng.mL(-1) to 100 μg.mL(-1). We observed that RMO caused a significant increase in rate of adrenaline auto-oxidation. On the other hand RMO did not present any scavenging effect in H2O2 formation in vitro. The results of this study revealed that RMO has both peripheral and central analgesic properties. The RMO, all doses, orally (p.o.) administered significantly inhibited (p < 0.05, p < 0.01 and p < 0.001) the acetic acid-induced writhings and two phases of formalin-induced nociception in mice.

CONCLUSION

The RMO demonstrated antioxidant and analgesic profile which may be related to the composition of the oil.

Protective effects of the active fraction from the tuber of Scirpus yagara in mouse endotoxin shock model

ETHNOPHARMACOLOGICAL RELEVANCE

Scirpus yagara Ohwi is a perennial, aquatic plant, whose dry tubers have long been used as Traditional Chinese Medicine (TCM) "Sanleng" for the treatment of postpartum abdominal pain, hyperemesis gravidarum, amenorrhea, dyspepsia and several inflammatory related diseases. Although it is known to have anti-inflammatory activities, its mechanism of action on lipopolysaccharide (LPS)-induced inflammation has not yet been identified in detail.This study was designed to investigate the anti-inflammatory activity of the active fraction (AF) from the tuber of Scirpusyagara both in vitro and in vivo.

MATERIALS AND METHODS

RAW264.7 macrophage was incubated for 16h with 1µg/ml of LPS in absence or presence of AF (0, 10, 50 and 100µg/ml) and the secretions of tumor necrosis-alpha (TNF-α) and interleukin-6 (IL-6) in the medium were determined by using an enzyme-linked immunosorbent assay (ELISA). In the in vivo study, mice were orally administrated with AF (50 and 300mg/kg) for three days consecutively. 1h after the last AF administration, the mice were intraperitoneally injected with LPS (15mg/kg), and the life span of LPS-challenged mice were determined. Furthermore, the levels of pro-inflammatory cytokines TNF-α and IL-6 in the serum, lung and liver were measured using ELISA kit, and histological change in lungs was examined by light microscopy. Additionally, the components of AF were analyzed by high performance liquid chromatography (HPLC) using a C18 column.

RESULTS

AF significantly decreased TNF-α and IL-6 production induced by LPS in RAW264.7 macrophage. In LPS-induced mouse endotoxin shock model, AF pre-treatment significantly improved the survival rate of mice. And LPS-induced increases of pro-inflammatory cytokines TNF-α and IL-6 in the serum, lung and liver were markedly suppressed by AF. Moreover, the histopathological examination indicated that AF could significantly attenuate lung tissues injury in endotoxemic mice. In addition, eight compounds (protocatechuic acid, vanillic acid, p-coumaric acid, ferulic acid, methyl-3,6-dihydroxy-2-[2-(2-hydroxyphenyl)-ethynyl] benzoate, sciryagarol I, sparstolonin B, SanLeng diphenyllactone) of AF were quantified by HPLC analysis.

CONCLUSIONS

These results suggested that AF protected mice against LPS-induced lethality by inhibiting the production of multiple cytokines and organ dysfunction. Thus AF may prove beneficial in the prevention and treatment of endotoxin shock.

Analysis in horse hair as a means of evaluating selenium toxicoses and long-term exposures

Horses are very susceptible to chronic selenosis if grazed on seleniferous forages for a prolonged period. In this study, mane and tail samples from horses that exhibited classical hoof lesions of chronic selenosis were analyzed by inductively coupled plasma mass spectrometry for selenium (Se) content. The horses had grazed for 6 months, from approximately May 15 until November 15, each year for three grazing seasons in a pasture containing seleniferous forages and water sources with elevated Se concentrations. The segmented hair samples showed a cyclic pattern in Se concentrations in the mane and tail, which corresponded to entering and exiting the contaminated pasture. The Se concentration in the tail of one horse could be traced for three grazing seasons. These results demonstrate that in some cases hair samples can be used to determine Se exposure in horses for up to 3 years postexposure.

Silica nanoparticles aid in structural leaf coloration in the Malaysian tropical rainforest understorey herb Mapania caudata

BACKGROUND AND AIMS

Blue-green iridescence in the tropical rainforest understorey sedge Mapania caudata creates structural coloration in its leaves through a novel photonic mechanism. Known structures in plants producing iridescent blues consist of altered cellulose layering within cell walls and in special bodies, and thylakoid membranes in specialized plastids. This study was undertaken in order to determine the origin of leaf iridescence in this plant with particular attention to nano-scale components contributing to this coloration.

METHODS

Adaxial walls of leaf epidermal cells were characterized using high-pressure-frozen freeze-substituted specimens, which retain their native dimensions during observations using transmission and scanning microscopy, accompanied by energy-dispersive X-ray spectroscopy to identify the role of biogenic silica in wall-based iridescence. Biogenic silica was experimentally removed using aqueous Na2CO3 and optical properties were compared using spectral reflectance.

KEY RESULTS AND CONCLUSIONS

Blue iridescence is produced in the adaxial epidermal cell wall, which contains helicoid lamellae. The blue iridescence from cell surfaces is left-circularly polarized. The position of the silica granules is entrained by the helicoid microfibrillar layers, and granules accumulate at a uniform position within the helicoids, contributing to the structure that produces the blue iridescence, as part of the unit cell responsible for 2 ° Bragg scatter. Removal of silica from the walls eliminated the blue colour. Addition of silica nanoparticles on existing cellulosic lamellae is a novel mechanism for adding structural colour in organisms.

Relationships between C3 plant foliar carbon isotope composition and element contents of grassland species at high altitudes on the Qinghai-Tibet Plateau, China

Relationships of foliar carbon isotope composition (δ(13)C) with foliar C, N, P, K, Ca, Mg contents and their ratios of 219 C3 species leaf samples, obtained in August in 2004 to 2007 from 82 high altitude grassland sites on the Qinghai-Tibet Plateau China, were examined. This was done with reference to the proposition that foliar δ(13)C increases with altitude and separately for the life-form groups of graminoids, forbs and shrubs and for the genera Stipa and Kobresia. For all samples, foliar δ(13)C was negatively related to foliar K, P and ∑K+ Ca+ Mg, and positively correlated to foliar C, C/N and C/P. The significance of these correlations differed for the taxonomic and life-form groups. Lack of a relationship of foliar δ(13)C with foliar N was inconsistent with the majority of studies that have shown foliar δ(13)C to be positively related to foliar N due to a decrease of Ci/Ca (the ratio between intercellular and atmospheric concentration of CO2) and explained as a result of greater photosynthetic capacity at higher foliar N concentration. However this inconsistency relates to other high altitude studies that have found that photosynthetic capacity remains constant as foliar N increases. After accounting for the altitudinal relationship with foliar δ(13)C, of the elements only the K effect was significant and was most strongly expressed for Kobresia. It is concluded that factors critical to plant survival and growth at very high altitudes, such as low atmospheric pressure and low temperatures, may preclude expression of relationships between foliar δ(13)C and foliar elements that have been observed at lower altitudes.

Changes in pH and organic acids in mucilage of Eriophorum angustifolium roots after exposure to elevated concentrations of toxic elements

The presence of Eriophorum angustifolium in mine tailings of pyrite maintains a neutral pH, despite weathering, thus lowering the release of toxic elements into acid mine drainage water. We investigated if the presence of slightly elevated levels of free toxic elements triggers the plant rhizosphere to change the pH towards neutral by increasing organic acid contents. Plants were treated with a combination of As, Pb, Cu, Cd, and Zn at different concentrations in nutrient medium and in soil in a rhizobox-like system for 48-120 h. The pH and organic acids were detected in the mucilage dissolved from root surface, reflecting the rhizospheric solution. Also the pH of root-cell apoplasm was investigated. Both apoplasmic and mucilage pH increased and the concentrations of organic acids enhanced in the mucilage with slightly elevated levels of toxic elements. When organic acids concentration was high, also the pH was high. Thus, efflux of organic acids from the roots of E. angustifolium may induce rhizosphere basification.

Antinociceptive, anti-inflammatory and antioxidant activities of aqueous extract from Remirea maritima (Cyperaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Remirea maritima Aubl., popularly known as "capim-da-praia", is popularly employed in the treatment of diarrhea, kidney disease, fever, and for analgesic and anti-inflammatory purposes through the preparation of teas. Few studies have focused on the chemical composition and its biological properties.

AIM OF THE STUDY

This work evaluated the antinocipetive, anti-inflammatory and antioxidant activities of the aqueous extract from Remirea maritima Aubl. as well as the isolation and identification of the chemical compounds.

MATERIALS AND METHODS

Compounds were isolated from aqueous extract of Remirea maritima through preparative HPLC and the structures were identified by means of NMR and MS analysis. The tests for antinociceptive, anti-inflammatory, and antioxidant activities, along with motor coordination test (Rota rod), were performed over the aqueous extract.

RESULTS

The phytochemical investigation of aqueous extract of Remirea maritima resulted in the isolation of three flavone glycosides. The structures of these compounds were determined by means of MS and 1D and 2D NMR data as vitexin-2″-O-β-D-glucopyranoside, isovitexin-2″-O-β-D-glucopyranoside, and luteolin-7-O-glucuronide. Acute pretreatment with aqueous extract (100, 200 or 400mg/kg, i.p.) caused a significant decrease (p<0.001) in the number of abdominal writhes. In the formalin test, higher doses significantly inhibited the late (inflammatory pain) phase of formalin-induced licking (p<0.05 or 0.001). In the hot plate test, there was no significant difference in nociceptive behavior, discarding the possible central effect of the aqueous extract. In the rota rod test, it was verified that the aqueous extract in all concentration evaluated does not alter the motor coordination of mice, such antinociceptive results were unlikely to be caused by motor abnormality. In the peritonitis test, induced by carrageenan, the treatment with aqueous extract produced a significant reduction in leukocyte migration in all concentration evaluated. Additionally, a significant reduction of lipoperoxidation (TBARS test) and in nitric oxide formation (.NO Scavenging assay) was observed in antioxidant activity assay.

CONCLUSION

The biological and phytochemical investigations of the aqueous extract of Remirea maritima resulted in the identification of three flavone glycosides that have been described here for the first time in Remirea and effective analgesic activity in various pain models, probably mediated via the inhibition of peripheral mediators which could be related to its strong antioxidant effect observed in vitro.

Bioassay-guided discovery of antibacterial agents: in vitro screening of Peperomia vulcanica, Peperomia fernandopoioana and Scleria striatinux

BACKGROUND

The global burden of bacterial infections is high and has been further aggravated by increasing resistance to antibiotics. In the search for novel antibacterials, three medicinal plants: Peperomia vulcanica, Peperomia fernandopoioana (Piperaceae) and Scleria striatinux (Cyperaceae), were investigated for antibacterial activity and toxicity.

METHODS

Crude extracts of these plants were tested by the disc diffusion method against six bacterial test organisms followed by bio-assay guided fractionation, isolation and testing of pure compounds. The minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations were measured by the microdilution method. The acute toxicity of the active extracts and cytotoxicity of the active compound were performed in mice and mammalian cells, respectively.

RESULTS

The diameter of the zones of inhibition (DZI) of the extracts ranged from 7-13 mm on Escherichia coli and Staphylococcus aureus of which the methylene chloride:methanol [1:1] extract of Scleria striatinux recorded the highest activity (DZI = 13 mm). Twenty-nine pure compounds were screened and one, Okundoperoxide, isolated from S. striatinux, recorded a DZI ranging from 10-19 mm on S. aureus. The MICs and MBCs indicated that the Peperomias had broad-spectrum bacteriostatic activity. Toxicity tests showed that Okundoperoxide may have a low risk of toxicity with an LC50 of 46.88 μg/mL.

CONCLUSIONS

The antibacterial activity of these plants supports their use in traditional medicine. The pure compound, Okundoperoxide, may yield new antibacterial lead compounds following medicinal chemistry exploration.

Removing heavy metals by in vitro cultures

In vitro roots cultures of Typha latifolia and Scirpus americanus aquatic plants have the capacity to remove Pb (II), Mn (II), and Cr (III) from the culture medium. Both species remove Cr and Pb by an absorption process, while Mn is mainly adsorbed to the root surface. This chapter describes a protocol for the establishment of in vitro roots cultures (nontransformed) from T. latifolia and S. americanus, and the procedure for the uptake analysis of Pb (II), Mn (II), and Cr (III) by roots.

The status and importance of crude protein and macro minerals in native pastures growing on Vertisols of the central highlands of Ethiopia

The effects of pasture management, season and soil nutrient status on crude protein (CP) and macro mineral concentration of native pasture was studied in the Vertisol areas of the central Ethiopian highland. Soil and herbage samples from 18 continuously grazed (CG) and 12 seasonally grazed (SG) pasture sites were analyzed for N, P, Ca, Mg, K and Na. Soil and dry season CG pasture samples were collected in January and February 2001 (dry season: November-February), while wet season CG and SG pasture samples were collected during September 2001 (wet season: April-October). The Potassium concentration (2.55%) of mixed herbage samples from SG pasture exceeded the K values (1.80%) from CG pasture (P < 0.01). Significant (P < 0.01) differences of CP and macro minerals concentrations were noted among forage species. The mean CP and K concentrations of herbage from CG pasture were higher (P < 0.01) during the wet than during the dry season (5.97 and 1.80% vs. 3.18 and 0.79%), while the opposite was true for Ca (0.49% vs. 0.61%) (P < 0.05). Regarding soil macro minerals and the corresponding herbage macro mineral concentrations, significant (P < 0.05) but inconsistent correlations were found for Ca, P, Mg and Na. The results suggest that pasture management, season and to some extend soil nutrient status, can affect herbage CP and macro mineral composition. The levels of CP in CG pasture and that of P and Na in both CG and SG pastures may fall below the requirements of grazing livestock. Resting at critical stages of the growth cycle of the forage species encouraged the recovery of desirable species. For this reason resting of pasture can contribute significantly to the quality of the native pastures of the Vertisols of the central Ethiopian highlands and should be encouraged.

Phosphorus transformations during decomposition of wetland macrophytes

The microbially mediated transformation of detrital P entering wetlands has important implications for the cycling and long-term sequestration of P in wetland soils. We investigated changes in P forms in sawgrass (Cladium jamaicense Crantz) and cattail (Typha domingensis Pers.) leaf litter during 15 months of decomposition at two sites of markedly different nutrient status within a hard-water subtropical wetland (Water Conservation Area 2A, Florida). Leaf litter decomposition at the nutrient enriched site resulted in net sequestration of P from the environment in forms characteristic of microbial cells (i.e., phosphodiesters and pyrophosphate). In contrast, low P concentrations at the unenriched site resulted in little or no net sequestration of P, with changes in P forms limited to the loss of compounds present in the initial leaf litter. We conclude that under nutrient-rich conditions, P sequestration occurs through the accumulation of microbially derived compounds and the presumed concentration of endogenous macrophyte P. Under nutrient-poor conditions, standing P pools within wetland soils appear to be independent of the heterotrophic decomposition of macrophyte leaf litter. These conclusions have important implications for our ability to predict the nature, stability, and rates of P sequestration in wetlands in response to changes in nutrient loading.

13C and 15N allocations of two alpine species from early and late snowmelt locations reflect their different growth strategies

Intense efforts are currently devoted to disentangling the relationships between plant carbon (C) allocation patterns and soil nitrogen (N) availability because of their consequences for growth and more generally for C sequestration. In cold ecosystems, only a few studies have addressed whole-plant C and/or N allocation along natural elevational or topographical gradients. (12)C/(13)C and (14)N/(15)N isotope techniques have been used to elucidate C and N partitioning in two alpine graminoids characterized by contrasted nutrient economies: a slow-growing species, Kobresia myosuroides (KM), and a fast-growing species, Carex foetida (CF), located in early and late snowmelt habitats, respectively, within the alpine tundra (French Alps). CF allocated higher labelling-related (13)C content belowground and produced more root biomass. Furthermore, assimilates transferred to the roots were preferentially used for growth rather than respiration and tended to favour N reduction in this compartment. Accordingly, this species had higher (15)N uptake efficiency than KM and a higher translocation of reduced (15)N to aboveground organs. These results suggest that at the whole-plant level, there is a compromise between N acquisition/reduction and C allocation patterns for optimized growth.

Effects of burn temperature on ash nutrient forms and availability from cattail (Typha domingensis) and sawgrass (Cladium jamaicense) in the Florida Everglades

Plant ash derived from fire plays an important role in nutrient balance and cycling in ecosystems. Factors that determine the composition and availability of ash nutrients include fire intensity (burn temperature and duration), plant species, habitat nutrient enrichment, and leaf type (live or dead leaf). We used laboratory simulation methods to evaluate temperature effects on nutrient composition and metals in the residual ash of sawgrass (Cladium jamaicense) and cattail (Typha domingensis), particularly on post-fire phosphorus (P) availability in plant ash. Live and dead leaf samples were collected from Water Conservation Area 2A in the northern Everglades along a soil P gradient, where prescribed fire may be used to accelerate recovery of this unique ecosystem. Significant decreases in total carbon and total nitrogen were detected with increasing fire temperature. Organic matter combustion was nearly complete at temperatures > or = 450 degrees C. HCl-extractable P (average, 50% of total P in the ash) and NH(4)Cl-extractable P (average, 33% of total P in the ash) were the predominant P fractions for laboratory-burned ash. Although a low-intensity fire could induce an elevation of P availability, an intense fire generally resulted in decreased water-soluble P. Significant differences in nutrient compositions were observed between species, habitat nutrient status, and leaf types. More labile inorganic P remained in sawgrass ash than in cattail ash; hence, sawgrass ash has a greater potential to release available P than cattail. Fire intensity affected plant ash nutrient composition, particularly P availability, and the effects varied with plant species and leaf type. Therefore, it is important to consider fire intensity and vegetation community when using a prescribed fire for ecosystem management.

Okundoperoxide, a bicyclic cyclofarnesylsesquiterpene endoperoxide from Scleria striatinux with antiplasmodial activity

Okundoperoxide (1) was isolated by bioassay-guided fractionation of extracts from Scleria striatinux (syn. S. striatonux). The compound contains a cyclic endoperoxide structural moiety and possesses moderate antimalarial activity.

Occurrence of sesquiterpene derivatives in Scleria striatonux de wild (Cyperaceae)

Scleria striatonux (Cyperaceae), a spice traditionally used in Cameroon, displayed an antiplasmodial activity. Two new sesquiterpenes, 1 (sclerienone A) and 2 (sclerienone B), have subsequently been isolated from the methylene chloride/methanol extract of the rhizome. Their separation involved a combination of methods including repeated silica gel open column chromatography, Sephadex LH-20 and semi-preparative HPLC. Structure elucidation was achieved by means of chemical tests and extensive spectral studies.

Seasonal changes of metal accumulation and distribution in common club rush (Schoenoplectus lacustris) and common reed (Phragmites australis)

In this study, two aquatic macrophytes Phragmites australis and Schoenoplectus lacustris and corresponding sediment samples were collected every three months from Lake Sapanca (Turkey) and analysed for their heavy-metal contents (Pb, Cr, Cu, Mn, Ni, Zn and Cd). Accumulation factor ratios of plant parts were calculated for all metals, and the two species were compared in terms of accumulation properties. The highest concentrations were measured in the root systems while relatively low concentrations were found in the rhizome and above-ground parts of the plants. The accumulation ratios of root for P. australis were usually higher than the ratios for S. lacustris. While the accumulation ratios of root were higher in winter than in the other seasons for P. australis, for S. lacustris the highest accumulation ratios were found in the autumn. Both plant species were found to be root accumulators of Pb, Cu, Mn, Ni, Zn and Cd.

Uptake and distribution of N, P and heavy metals in three dominant salt marsh macrophytes from Yangtze River estuary, China

We examined the variation in aboveground biomass accumulation and tissue concentrations of nitrogen (N), phosphorus (P), copper (Cu), zinc (Zn) and lead (Pb) in Phragmites australis (common reed), Spartina alterniflora (salt cordgrass), and Scirpus mariqueter throughout the growing season (April-October 2005), in order to determine the differences in net element accumulation and distribution between the three salt marsh macrophytes in the Yangtze River estuary, China. The aboveground biomass was significantly greater in the plots of S. alterniflora than in the plots of P. australis and S. mariqueter throughout the growing season (P<0.05). In August, the peak aboveground biomass was 1246+/-89 gDW/m(2), 2759+/-250 gDW/m(2) and 548+/-54 gDW/m(2) for P. australis, S. alterniflora and S. mariqueter, respectively. The concentrations of nutrients and heavy metals in plant tissues showed similar seasonal patterns. There was a steady decline in element concentrations of the aboveground tissues from April to October. Relative element concentrations in aboveground tissues were at a peak during the spring sampling intervals with minimum levels during the fall. But the concentrations of total nitrogen and total phosphorus in the belowground tissues were relatively constant throughout growing season. Generally, trace metal concentrations in the aboveground tissues of S. mariqueter was the highest throughout the growing season, and the metal concentrations of S. alterniflora tissues (aboveground and belowground) were greater than those of P. australis. Furthermore, the aboveground pools of nutrients and metals were consistently greater for S. alterniflora than for P. australis and S. mariqueter, which suggested that the rapid replacement of native P. australis and S. mariqueter with invasive S. alterniflora would significantly improve the magnitude of nutrient cycling and bioavailability of trace metals in the salt marsh and maybe transport more toxic metals into the water column and the detrital food web in the estuary.

Heavy metal uptake by Scirpus Littoralis Schrad. from fly ash dosed and metal spiked soils

Scirpus littoralis is a wetland plant commonly found in Yamuna flood plains of Delhi, India. The ability of Scirpus littoralis to take up and translocate five metals- Mn, Ni, Cu, Zn and Pb from fly ash dosed and metal spiked soils were studied under waterlogged and field conditions for 90 days. Scirpus littoralis accumulated Mn, Ni, Cu, Zn and Pb upto a maximum of 494.92, 56.37, 144.98, 207.95 and 93.08 ppm dry wt., respectively in below ground organs (BO) in 90 days time. The metal content ratios BO/soil (B/S) were higher than shoot/soil ratios (T/S) for all the metals, the highest being for Ni. Metal ratios BO/water (B/W) were also higher than shoot/water (T/W) ratios but the B/W ratio was maximum for Zn. The changes in nutrient status (N, P) in soil water and plants were also studied at interval of 30 days. The Pearson's correlation between metal uptake and N, P uptake were calculated. All the metals except Ni showed negative correlation with nitrogen but they were all non-significant. However, P uptake showed positive correlations with all the metals and all were significant at 1% confidence limit.

[Fingerprint of ultramicro decoction piece of Rhizoma Cyperi by pergormance gas chromatography]

OBJECTIVE

To study the ultramicro decoction piece of Rhizoma Cyperi and establish its fingerprint.

METHODS

Capillary gas chromatography was used to analyze the extracts of ultramicro decoction piece of Rhizoma Cyperi from 10 different sources.

RESULTS

The Fingerprint of ultramicro decoction piece of Rhizoma Cyperi was composed of 50 peaks, containing 10 characteristic peaks.

CONCLUSION

The fingerpint can be used to control the ultramicro decoction piece of Rhizoma Cyperi qualities.

Accumulation of As, Cd and selected trace elements in tubers of Scirpus maritimus L. from Doñana marshes (South Spain)

The collapse of a pyrite-mining, tailing dam on 1998 contaminated an area of 4286 ha along the Agrio and Guadiamar river valleys in southern Spain. Over 2700 ha of the Doñana marshes, an important wintering area for wetland European birds, were contaminated. This study reports analyses of the tubers of Scirpus maritimus (an important food for greylag geese, Anser anser) collected in 2000 in the "Entremuros" (spill-affected area) and in nearby unaffected Doñana marshes (control areas). In the spill-affected area mean tuber tissue concentrations of Cd (0.25 mg kg-1) and Zn (61 mg kg-1) were greater than in those tubers from the control area (0.02 mg kg-1 for Cd, and 22 mg kg-1 for Zn); values of Cd and Zn in "Entremuros" (samples collected two years after the mine spill) were much smaller than those reported only a few months after the accident. Trace elements (As, Fe, Mn and Tl, and to a lesser extent Cd and Pb) showed a preferential accumulation in the outer skin of tubers. Surprisingly, concentrations of As and Fe were greater in tubers from some marsh sites not affected by the mine-spill than in tubers from the "Entremuros". We suggest that relic river channels within the Doñana marshes may be contaminated by trace elements from historic mining activities. An exhaustive study of macrophytes and other plant species in this area is recommended to identify potential risks to wildlife.

Nepalensinols D-G, new resveratrol oligomers from Kobresia nepalensis (Cyperaceae) as potent inhibitors of DNA topoisomerase II

Four new resveratrol oligomers, nepalensinols D-G, were isolated from the stem of Kobresia nepalensis (Cyperaceae). The structures were determined by detailed NMR spectral analysis. The compounds were assessed for their inhibitory activity against human topoisomerase II, a potential target of anti-tumor agents. These stilbenoids showed potent inhibitory activity against human topoisomerase II with IC50 values of 5-15 microM.

The effect of the size of particles on mineralization of Oxycaryum cubense (Poepp. & Kunth) Lye

Assays were carried out to evaluate effects of detritus size on the mineralization of an aquatic macrophyte, the Oxycaryum cubense. Samples of plant and water were collected from an oxbow lake, the Infernão lagoon (21° 35' S and 47° 51' W) located at Mogi Guaçu river floodplain. The plants were taken to the laboratory, washed under tap water, dried (50 °C) and fractioned into six groups according to their size, viz. 100, 10, 1.13, 0.78, 0.61 and 0.25 mm. Decomposition chambers were prepared by adding 1.0 g of plant fragments to 4.1 L of water lagoon. In sequence, the incubations were aerated and the concentrations of dissolved oxygen, the pH, the electric conductivity and the temperature were monitored for 120 days. The occurrence of anaerobic processes was avoided by reoxygenating the solutions. The experimental results were fitted to a first order kinetic model and the consumption of dissolved oxygen from mineralization processes was obtained. The physical process of fragmentation of O. cubense detritus is unlikely to promote the consumption of higher quantities of dissolved oxygen in mineralization processes meaning that fragmentation should not interfere in the balance of DO in this aquatic system, however fragmentation processes favored the acidification and increased the liberation of dissolved ions from the Infernão lagoon.

[Study on the chemical substrates of SFE extract from Rhizoma Cyperi]

OBJECTIVE

To extract the effective part of Rhizoma Cyperi and study the chemical constituents of diffrent parts.

METHODS

The extract of Rhizoma Cyperi was obtained by SFE and dealed with molecular distillation, then the effective components was enriched. The chemical compositions were separated and identified by GC/MS.

RESULTS

The content of volatile oil in the extract upgraded from 43.2% to 86.0% by molecular distillation, and the relative amount of cyperene and (+) -alpha-cyperone from 20.2% to 38.6%. Fatty acids was not found in Rhizoma Cyperi-MD1.

CONCLUSION

The SFE of Rhizoma Cyperi could be refined with molecular distillation. The active ingredients, such as volatile oil and alpha-cyperolone, were remained effectively. The ineffective ingredients fatty acids were removed.

Stilbenoids of Kobresia nepalensis (Cyperaceae) exhibiting DNA topoisomerase II inhibition

Resveratrol oligomers, nepalensinol A, B and C, were isolated from the stem of Kobresia nepalensis (Cyperaceae). The structures were established on the basis of chemical properties and spectroscopic evidence including 2D NMR spectroscopic analysis. Nepalensinol A, B and C showed a potent inhibitory effect on topoisomerase II -- stronger than etoposide (VP-16), a topoisomerase II inhibitor used as an anti-cancer drug. Nepalensinol B, in particular, exhibited the most potent activity with an IC(50) of 0.02 microg/ml.

HCHs and DDTs in salt marsh plants (Scirpus) from the Yangtze estuary and nearby coastal areas, China

HCHs and DDTs in salt marsh plants taken from intertidal flats in the Yangtze estuary and coastal area in April and July 2002 were determined by GC-ECD. A significant seasonal effect was observed for HCHs and DDTs in sources and concentration levels in different sample types including above-ground tissues and roots as well as the whole plants and rhizospheric sediments. The results indicated that the concentration of t-HCH was higher in the above-ground tissues than in their roots in April; however, the partitioning of DDTs between contaminated sediments and the roots showed the higher concentrations of t-DDT in their roots. HCHs and DDTs concentration levels were higher in above-ground tissues than in roots in July. BCFs of HCHs and DDTs exhibited lower values with higher levels of contaminants in sediments, and higher values with lower levels in sediments.

Flavonoids from the stem of Eriophorum scheuchzeri

Activity-guided isolation of antifungal, antibacterial, and antioxidant compounds from the dichloromethane extract of the aerial parts of Eriophorum scheuchzeri led to the isolation of eight flavonoids. Three isoflavones and one flavanone are new natural compounds. The isolation of the bioactive compounds was performed by centrifugal partition chromatography. Fractions and pure compounds were monitored by a direct TLC bioautographic assay. Their structures were elucidated by spectroscopic and chemical methods.

Screening the wetland plant species Alisma plantago-aquatica, Carex rostrata and Phalaris arundinacea for innate tolerance to zinc and comparison with Eriophorum angustifolium and Festuca rubra Merlin

Several wetland plant species appear to have constitutive metal tolerance. In previous studies, populations from contaminated and non-contaminated sites of the wetland plants Typha latifolia, Phragmites australis, Glyceria fluitans and Eriophorum angustifolium were found to be tolerant to high concentrations of metals. This study screened three other species of wetland plants: Alisma plantago-aquatica, Carex rostrata and Phalaris arundinacea for innate tolerance to zinc. The degree of tolerance was compared to known zinc-tolerant E. angustifolium and Festuca rubra Merlin. It was found that A. plantago-aquatica and P. arundinacea did not posses innate tolerance to zinc, but that C. rostrata was able to tolerate elevated levels of zinc, at levels comparable to those tolerated by E. angustifolium and F. rubra Merlin. The findings support the theory that some wetland angiosperm species tend to be tolerant to exposure to high levels of metals, regardless of their origin.

Oil spill in the Rio de la Plata estuary, Argentina: 1. Biogeochemical assessment of waters, sediments, soils and biota

Aliphatic (ALI) and aromatic (ARO) hydrocarbon concentrations, composition and sources were evaluated in waters, sediments, soils and biota to assess the impact of approximately 1000 tons of oil spilled in Rio de la Plata coastal waters. Total ALI levels ranged from 0.4-262 microg/l in waters, 0.01-87 microg/g in sediments, 5-39 microg/g in bivalves, 12-323 microg/g in macrophytes to 948-5187 microg/g in soils. ARO varied from non-detected 10 microg/l, 0.01-1.3 mug/g, 1.0-16 microg/g, 0.5-6.9 microg/g to 22-67 microg/g, respectively. Offshore (1, 5, 15 km) waters and sediments were little affected and contained low background hydrocarbon levels reflecting an effective wind-driven transport of the slick to the coast. Six months after the spill, coastal waters, sediments, soils and biota still presented very high levels exceeding baseline concentrations by 1-3 orders of magnitude. UCM/resolved aliphatic ratio showed a clear trend of increasing decay: coastal waters (3.3) < macrophytes (6.7) < soils (9.4) < offshore sediments (13) < coastal sediments (17) < clams (52). All environmental compartments consistently indicated that the most impacted area was the central sector close to Magdalena city, specially low-energy stream embouchures and bays which acted as efficient oil traps. The evaluation of hydrocarbon composition by principal component analysis indicated the predominance of biogenic (algae, vascular plant cuticular waxes), background anthropic, pyrogenic and diagenetic hydrocarbons, offshore and in non-impacted coastal sites. In contrast, polluted stations presented petrogenic signatures characterized by the abundance of isoprenoids, low molecular weight n-alkanes and methylated aromatics in different stages of alteration. The petrogenic/biogenic ratio (<n-C22 + isoprenoids/n-C15 + n-C17 + > n-C23) and petrogenic/pyrogenic relationship (methylated/unsubstitued PAH) discriminated the samples according to the different degree of impact. The following paper present the results of the study of the progress of hydrocarbon disappearance in sediments and soils 13 and 42 months after the spill.

Nitrogen and phosphorus accumulation and biomass production by Scirpus sylvaticus and Phragmites australis in a horizontal subsurface flow constructed wetland

We studied plant biomass production and nutrient accumulation by wood club-rush (Scirpus sylvaticus) and reed (Phragmites australis) in a horizontal subsurface flow constructed wetland in 2001 and 2002. The wetland consists of two beds, one with dry and another with wetter conditions. From both beds, 5 above-ground, below-ground, and litter samples were taken in the summer, during the maximum flowering period of the dominant species. The average dry biomass of whole plant and litter was considerable higher in 2002 (3071 g m(-2)) than in 2001 (620 g m(-2)) due to the climatic conditions. The average dry weight biomass of 5 plots in 2001 was 513 g m(-2) in the dry bed and 729 g m(-2) in the wet bed. In 2002 these values were 2,520 and 3,765, respectively. Variations in biomasses will also appear in values for nutrient accumulation, in all cases the N and P accumulation was higher in 2002. The average nitrogen accumulation by plants was 16.6 g m(-2) in the wet and 10.7 g m(-2) in the dry bed in 2001, and 51.7 and 83.5 g m(-2) in 2002 respectively. Phosphorus accumulation was higher in the wet bed during 2001--2.8 g m(-2), in the dry bed this value was 1.9 g m(-2). In 2002, the phosphorus accumulation was higher in the dry bed--12.8 g m(-2), in the wet bed it was 12.43 g m(-2). The total biomass at the same conditions in the wet bed was slightly higher in case of wood club-rush--765 g m(-2) in 2001 and 3846 g m(-2) in 2002, same values for reed were 674 g m(-2) and 3,646, respectively.

Organochlorine pesticides sequestered in the aquatic macrophyte Schoenoplectus californicus (C.A. Meyer) Soják from a shallow lake in Argentina

This study was conducted in Los Padres Lake from Argentina in order to assess the ability of Schoenoplectus californicus to bioconcentrate organochlorine pesticides (OCPs). Bulrush tissues, superficial and near root sediments were collected from the input and the output creek areas. OCP analyses were carried out by GC-ECD. Samples from the input creek area showed the higher OCP levels as a result of contaminants washed down from upstream agricultural fields. Bulrush roots accumulated the highest concentrations of pollutants (30.2-45.7ngg(-1) dry weight). DDTs and chlordanes predominated in sediments and roots besides endosulfan sulfate. The sediments constitute the main source for these OCPs partitioning to bulrush. Stems mainly exposed to water column accumulated preferentially the less hydrophobic pesticides, such as HCHs and endosulfans. We have confirmed the important role of S. californicus in the contaminant removal from sediments. Therefore, this macrophyte can be used as a tool for field studies of OCP pollution monitoring and remediation.

Steroids and triterpenes from Eleocharis acutangula and E. sellowiana (Cyperaceae)

From the hexane extract of the underground parts of Eleocharis acutangula (Roxb.) Schult., lup-20(29)-ene-3beta,16beta-diol and a mixture of campesterol, stigmasterol and sitosterol were isolated. The hexane extracts of aerial and underground parts of E. sellowiana Kunth furnished two new substances, namely neohop-13(18)-en-3alpha-ol and stigmast-22-en-3beta,6beta,9alpha-triol, together with a mixture of steroids, betulinic acid, stigmast-4-en-6beta-ol-3-one and fern-9(11)-en-3alpha-ol. The molecular structures were determined by spectral analysis (1D- and 2D-NMR experiments and MS) and comparison with literature data.

Absolute structures of some naturally occurring isopropenyldihydrobenzofurans, remirol, remiridiol, angenomalin, and isoangenomalin

The absolute structures of some naturally occurring chiral 2-isopropenyl-2,3-dihydrobenzofurans, (+)-remirol (1a), (+)-remiridiol (1b), (+)-angenomalin (2), and (+)-isoangenomalin (3), were studied by respective chiral synthesis. Kinetic resolutions of racemic 2-isopropenyl-2,3-dihydrobenzofurans, 2-isopropenyl-4,6-dimethoxy-2,3-dihydrobenzofuran (4), 4-hydroxy-2-isopropenyl-2,3-dihydrobenzofuran-5-carbaldehyde (8), and 2-isopropenyl-6-(MOM)oxy-2,3-dihydrobenzofuran-5-carbaldehyde (11c), by Sharpless dihydroxylation using (DHQ)(2)AQN or (DHQD)(2)AQN gave the corresponding chiral 2-isopropenyl-2,3-dihydrobenzofurans. Chiral (S)-(+)-4 (99% ee, using (DHQD)(2)AQN) was converted to natural remirol (S)-(+)-1a and then to natural remiridiol (S)-(+)-1b. (S)-(+)-8 (97% ee, using (DHQD)(2)AQN) was converted to natural angenomalin (S)-(+)-2. (R)-(-)-11c (>99% ee, using (DHQ)(2)AQN), was converted to natural isoangenomalin (R)-(+)-3. Thus, the absolute structures of natural remirol (+)-1a and remiridiol (+)-1b and angenomalin (+)-2 were determined to be S, and the structure of natural isoangenomalin (+)-3 was R.

The effect of particle size on the leaching of Scirpus cubensis Poepp & Kunth

An investigation was made on the effects of detritus particle size on leaching rates in organic matter, and the associated environmental changes caused by detritus re-cycling in an oxbow lake (Lagoa do Infernão). Experiments were conducted during the decay of an aquatic macrophyte specie, S. cubensis, which in turn led to the formation of colored compounds. The S. cubensis were collected from the Lagoa do Infernão and taken to the laboratory where they were washed, dried, and fractionated using a sieve pedological set. The detritus was classified into six groups according to size, viz. 100, 10, 1.13, 0.78, 0.61, and 0.25 mm. Overall, the fragmentation process tended to increase the detritus fraction to be dissolved and to decrease the leaching rates owing to the possible dissolution of refracting matter. Fragmentation also caused the amount of colored compounds to increase and appeared to favor dissolved electrolyte release. Finally, in Lagoa do Infernão fragmentation is probably mediated by the metabolic action of benthic communities.

Mineral content as a basis for food selection by western lowland gorillas in a forest clearing

The forests in northwest Republic of Congo contain a number of herbaceous swamp clearings that provide foraging sites for lowland gorillas (G.g. gorilla). A 10-month study at the Maya Nord clearing (Parc National d'Odzala) showed that feeding activities occupied 72% of the time visiting gorillas spent on the clearing. They fed on four plant species: Enydra fluctuans (Asteraceae), Cyperus sp., Pycreus mundtii, and Rhynchospora corymbosa (Cyperaceae) among the 45 species recorded on the clearing. These clearing food species have higher mineral contents (especially Na and Ca) than the dominant Marantaceae species (Haumania liebrechtsiana) that constituted a staple food plant for gorillas in this forest. They also have higher potassium contents and contain less lignin than non-eaten clearing items/species. Finally, the most actively searched for clearing food (Enydra fluctuans) was characterized by the highest amount of Na and Ca. These results suggest that the mineral content (especially in Na, Ca, and/or K) could determine the feeding selectivity of gorillas at the clearing. They also tend to confirm that the amount of fiber plays a deterrent role in food selectivity, as has been found by many authors. The high density of gorillas in that region could result from the combination of the large areas of Marantaceae forests that provide abundant though monotonous food, and the number of clearings that provide sufficient mineral supplies. Clearings should thus be considered as key habitats for the conservation of gorillas.