Pharmacokinetic and metabolism studies of rohitukine in rats by high performance liquid-chromatography with tandem mass spectrometry

A sensitive, selective, and rapid high performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed for the quantification of rohitukine in rat plasma. HPLC was performed using a Symmetry-Shield C₁₈ (5 μ, 4.6 × 150 mm) column, and isocratic elution with ammonium acetate buffer (pH 4; 10 mM):methanol (08:92, v/v) at a flow rate of 0.6 mL/min. Sample clean-up involved solid phase extraction (SPE) of analyte and internal standard (phenacetin) from 100 μL plasma. The parent → product ion transitions (MRM) for analyte and IS were 306.1 → 245.1 m/z and 180.1 → 138.1 m/z respectively, and were monitored on a triple quadrupole mass spectrometer, operating in positive ion mode. The method was validated across the dynamic concentration range of 5–500 ng/mL for rohitukine, with a fast run time of 4.5 min. The analytical method measured concentrations of rohitukine with accuracy (% bias) of <± 10% and precision (% RSD) of <± 12%. Rohitukine was stable during the battery of stability studies viz., bench-top, auto-sampler, freeze/thaw cycles and 30 days of storage in a freezer at − 70 ± 10 °C. Finally, the applicability of this assay has been successfully demonstrated in vivo pharmacokinetic and in vitro metabolism studies in Sprague–Dawley rat. This method will therefore be highly useful for future preclinical and clinical pharmacokinetic studies of rohitukine.     

A new glucomannan from Bletilla striata: Structural and anti-fibrosis effects

A novel water-soluble polysaccharide, designated Bletilla striata polysaccharide b (BSPb), was isolated from a traditional Chinese medicinal herb, Bletilla striata. The crude polysaccharide was obtained by hot water extraction and purified by ion-exchange chromatography. The molecular weight was 260 kDa as determined by HPGPC (high performance gel permeation chromatography). Monosaccharide analysis showed that BSPb contained glucose and mannose with a molar ratio of 3:1. Methylation and spectroscopic analyses with 1D and 2D NMR spectroscopy showed that the backbone of BSPb is mainly composed of (1 → 2)-linked α-d-mannopyranose and (1 → 4)-linked β-d-glucopyranose residues. In this study, BSPb plays an important role in protection against the renal fibrosis effect, which is probably mediated by down-regulated TGF-β RI, TGF-β RII, and α-SMA in vitro.     

Different pharmacokinetics of the two structurally similar dammarane sapogenins,protopanaxatriol and protopanaxadiol,in rats

Dammarane Sapogenins (DS), with main ingredients of protopanaxatriol (PPT, 33%) and protopanaxadiol (PPD, 16%), is an alkaline hydrolyzed product of ginsenosides and had significant activities in improving learning and memory and decreasing chemotherapy-induced myelosuppression. In the present study, the pharmacokinetics and oral bioavailabilities of PPT and PPD were investigated when a single dose of DS was administrated orally (75 mg/kg) and intravenously (i.v., 30 mg/kg) to rats. Their in vitro stabilities in the GI tract were also investigated. PPT and PPD concentrations were measured by LC–MS. The results showed that PPT was eliminated rapidly from the body with an average t_{1/2, λz} value of 0.80 h and CL of 4.27 l/h/kg after i.v. administration, while PPD was eliminated relatively slowly with a t_{1/2, λz} of 6.25 h and CL of 0.98 l/h/kg. After oral administration, both PPD and PPT could be absorbed into the body, but their systemic exposures were quite different. PPT was absorbed into the body quickly, with a T_max of 0.58 h and a C_max of 0.13 μg/ml, while PPD was absorbed relatively slowly with a T_max of 1.82 h and a C_max of 1.04 μg/ml. The absolute bioavailabilities of PPT and PPD were estimated as 3.69% and 48.12%, respectively. The stability test found that PPT was instable in the stomach with 40% degradation after 4 h incubation at 37 °C, both in pH 1.2 buffer and in the stomach content solution. The instability in the stomach might be one of the reasons for PPT's poor bioavailability.     

Pharmacokinetic study of eight coumarins of Radix Angelicae Dahuricae in rats by gas chromatography–mass spectrometry

A sensitive, specific gas chromatography–mass spectrometry (GC–MS) method was established for the quantitative determination of eight coumarins of Radix Angelicae Dahuricae including coumarin, isopsoralen, psoralen, xanthotoxin, bergapten, osthole, imperatorin and oxypeucedanin in rat plasma. Nitrendipine was used as the internal standard (IS). The plasma samples were extracted by acetonitrile. GC separation was accomplished on a DB-5MS column with temperature programmed from 160 °C (17 min) to 190 °C (10 min) at the rate of 20 °C/min, then to 240 °C (5 min) at 20 °C/min, and finally to 280 °C (14 min) at 20 °C/min. The detection was performed on a quadrupole mass spectrometer detector operated by full-scan mode (m/z 50–500). The lower limit of quantitation was 5–10 ng/mL for eight coumarins, and the linear range was 5–1000 ng/mL for the coumarins (R² > 0.9990). All the validation data were within the required limits. After oral administration, the plasma concentration–time curves showed that the time for maximum concentration (T_max) was 1.29 for coumarin, 1.83 for isopsoralen, 1.93 for psoralen, 1.30 for xanthotoxin, 2.04 for bergapten, 0.64 for osthole, 1.41 for imperatorin and 0.51 h for oxypeucedanin. The plasma concentration of the eight coumarins was low, with a mean maximum plasma concentration (C_max) < 6.41 μg/mL. Pharmacokinetic data analysis showed that the eight coumarins had different pharmacokinetic characteristics after oral administration. The method was successfully applied to pharmacokinetic studies of eight coumarins after oral administration in rats.     

Estimating water use of sclerophyllous species under East-Mediterranean climate: III. Tabor oak forest sap flow distribution and transpiration

The annual course of daily transpiration and the hydrological balance of a Tabor oak forest were determined. The study was done in a representative forest within the natural geographical range of the species in the lower Galilee region of Israel. The climate is sub-humid with a rainless dry season from May to October. A partial water balance of a 0.1 ha area supporting an average of 14 trees was calculated from: (a) soil water content (SWC) measured by a Neutron Probe at depths of from 0.2 to 8 m, and (b) daylight transpiration rate measured with sap flow sensors by the heat pulse technique.Soil–bedrock complex water content (%) in the first 2 m of the profile fluctuated strongly between 5 and 20% depending on the season. The water content increased with depth from about 10% at 2.0 m depth to more than 20% at 5.0 m depth. For depths exceeding 5.5 m seasonal fluctuations in water content were negligible and water content ranged from 30 to 35%. After a dry winter, water content generally decreased within the main root zone down to about 2.0 m depth. Monthly changes in water content (mm) were greatest at depths of 0.35–1.0 m. Only minor changes in the soil–bedrock complex water content were recorded at greater depths. After a very rainy winter (2002/2003), decreases in soil–bedrock complex water content in the upper 2 m were much larger than after a dry winter. Fluctuations of soil–bedrock complex water content in deeper regions were larger in the wetter year, probably the result of drainage.Sap velocity was measured at six depths in the sapwood, from 4 to 44 mm, at 8 mm intervals. Sap velocity declined with depth, hence, sap flux density too.Based on sap velocity measurements performed during 4 years, the annual average daily transpiration (T) was 0.796 mm/day. This sums up to 239 mm during ∼300 days of leaf carriage, i.e. 41.3% of the 578 mm average annual rainfall for the area in the last 50 years. In a relatively dry year (rainfall of 432.7 mm) total water withdrawal from the 8 m soil–bedrock profile was 81% of the annual rainfall; of this amount 69% were transpired by the oak trees (239.0 mm), or 55% of the annual rainfall. In a relatively wet year (annual rainfall 801.4 mm) total water withdrawal was 67%; of this amount 45% would be transpired by the oak trees, or 30% of the annual rainfall.     

In vitro permeability analysis,pharmacokinetic and brain distribution study in mice of imperatorin,isoimperatorin and cnidilin in Radix Angelicae Dahuricae

Coumarins are important constituents of Radix Angelicae Dahuricae, a well-known traditional Chinese medicine possess several known bioactivities with potentials in the treatment of central nervous system diseases. By using an HPLC–MS/MS method, we analyzed the in vivo plasma and brain pharmacokinetics of three ingredients of coumarins, including imperatorin, isoimperatorin and cnidilin in mice after oral administration of Dahuricae extract at doses of 800 mg/kg. The biosamples were prepared using acetonitrile precipitation and the separation was achieved on an XDB-C18 column by gradient elution. The BBB permeability and P-gp-mediated efflux were further examined in Madin Canine kidney cells transfected with full length cDNA for human multidrug resistance gene1 (MDCKII-MDR1). Our results demonstrate that the method has excellent and satisfactory selectivity, sensitivity, linearity, precision, and accuracy for simultaneous determination of imperatorin, isoimperatorin and cnidilin. The pharmacokinetics parameters were determined by using noncompartmental analyses, including the AUC_(0 − t) in plasma (1695.22, 1326.45 and 636.98 mg*h/L), the AUC_(0 − t) in brain (1812.35, 2125.17 and 1145.83 ng*h/g) as well as the T_1/2 in plasma (0.66, 0.82, 0.97 h) and brain (0.96, 1.1, 0.99 h) for imperatorin, isoimperatorin and cnidilin, respectively, suggesting that the three coumarins could easily pass through the BBB in vivo. In the in vitro model we observed high permeability of imperatorin and isoimperatorin with the P-gp-mediated efflux ratios of 0.53 and 0.06, as well as medium permeability of cnidilin with 0.82. All data suggest that these three coumarins have high BBB permeability and have pharmacokinetic potentials for the treatment of central nervous system diseases.     

New cytotoxic triterpenoid saponins from the whole plant of Clematis lasiandra Maxim

Four new oleanane type triterpenoid saponins (1–4) and three known saponins (5–7) were isolated from the whole plant of Clematis lasiandra Maxim. The structures of the four new compounds were elucidated as 3-O-β-d-ribopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-[β-d-glucopyranosyl-(1 → 4)]-β-d-xylopyranosyl hederagenin (1), 3-O-β-d-ribopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-β-d-xylopyranosyl oleanolic acid 28-O-β-d-glucopyranosyl ester (2), 3-O-β-d-ribopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-β-d-xylopyranosyl hederagenin (3) and 3-O-β-d-ribopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-[β-d-glucopyranosyl-(1 → 4)]-α-l-arabinopyranosyl hederagenin (4) on the basis of extensive spectroscopic analysis and chemical evidence. Compounds 1–7 were evaluated for their cytotoxicity against human tumor cell lines HL-60, Hep-G2 and SGC-7901, and all of the evaluated saponins showed significant cytotoxicity to those three tumor cell lines with IC₅₀ in the range from 1.40 to 19.50 μmol/L except for compounds 2 and 6.     

Wood density of trees in open savannas of the Brazilian Amazon

Studies on basic density of woody species in Amazonian savannas are needed to convert data on woody volume to biomass. These ecosystems, which have large carbon stocks, emit greenhouse gases annually due to frequent burnings. Basic density (g cm⁻³: oven-dry weight/wet volume), measured from complete sample disks (bark, sapwood and heartwood), was calculated for the most abundant woody species in three types of open savannas (Sg: grassy-woody savanna; Sp: savanna parkland; Tp: steppe-like parkland) in Roraima, a state in the northern part of Brazil’s Amazon region. The species selected represent 90–95% of the woody biomass estimated in these ecosystem types. Seven additional species were lumped in an “others” group. In total, we sampled 107 trees: 40 in Sg, 37 in Sp and 30 in Tp. Bowdichia virgilioides (0.516 ± 0.021 (S.E.) g cm⁻³) was the species with the highest basic density, followed by the “others” group (0.485 ± 0.057 g cm⁻³), Curatella americana (0.413 ± 0.028 g cm⁻³), Byrsonima crassifolia + B. coccolobifolia (0.394 ± 0.019 g cm⁻³), Himatanthus articulatus (0.375 ± 0.020 g cm⁻³) and B. verbascifolia (0.332 ± 0.020 g cm⁻³). Basic density of the species with the greatest woody biomass in Roraima’s open savannas (C. americana and B. crassifolia + B. coccolobifolia) did not differ significantly at the 5% level (ANOVA) among the three ecosystem types studied. Wood basic density in these savannas (weighted mean = 0.404 ± 0.025 g cm⁻³) is lower than that in Amazonian forests (weighted mean = 0.680 g cm⁻³). These results reduce uncertainty in calculations of carbon stocks and of greenhouse gas emissions from clearing and burning tropical savanna.     

Utilization and traditional strategies of in situ conservation of iroko (Milicia excelsa Welw. C.C. Berg) in Benin

Socio-cultural surveys were carried out on the basis of a questionnaire administered on 346 respondents in order to investigate cultural and ethnobotanic uses of Milicia excelsa in Benin.M. excelsa contributes to cure 45 human diseases. The different parts of the tree used are leaves (30.3%), bark (25.8%), root (23.6%), latex (10.1%), flaking bark (6.7%), wood, calcium concentrated in old trees, and gum (1.1% each). Fruits or seeds are rarely used. Six different forms of utilization were recorded: soaking (46.3%), bark or leaves decoction (32.8%), herb tea (11.9%), powder (6.0%), leaves or bark grounded and rolled up into ball (1.5%), component of offering to fetish (1.5%). Iroko wood is also used in carpentry and joinery for construction purposes; furniture as well as for building boats/canoes.Iroko tree is used as the conservatory of cultural values and incarnates many divinities, which differ significantly from one province to another (χ² = 1830.27; d.f. = 25; P < 0.01%). There is a significant difference between the provinces in respect of the recognition of the species (χ² = 268.71; d.f. = 17; P ≤ 0.01%) and the population awareness about iroko as a sacred tree also varied from one province to another (χ² = 308.66; d.f. = 27; P ≤ 0.01%).Veneration of the tree is the main approach of its conservation by local people. M. excelsa is conserved on farm, in sacred groves, in public places and in cemeteries. The different sacred objects used to symbolize the divinities incarnated by iroko are: pottery (36.36%), iron (11.11%), calabash (4.04%), candle (2.02%), piece of cloth (18.18%), sacrifice (13.13%), piece of money (3.0%), stone (2.05%), glassware (broken bottle, 2.02%), and convent (8.08%). There is a highly significant difference between provinces as far as the sacred objects are concerned (χ² = 183.037; d.f. = 19 and P < 0.001%). The conservation purposes also vary significantly from one region to other (χ² = 894.47; d.f. = 31; P < 0.01%).     

Population structure and nut yield of a Bertholletia excelsa stand in Southwestern Amazonia

Although Brazil nut (B. excelsa) is often touted as one of the most economically successful NTFPs, little is known about the population structure of this species within its natural range in Southwestern Amazonia or ecological factors that affect fruit production. Since these are considered fundamental for sustainable resource management, we examined a natural Brazil nut stand in an extractive reserve in Acre, Brazil, posing the following questions: (1) What is the spatial distribution, species density, and size–class structure of B. excelsa? and (2) What tree-level factors influence Brazil nut production? In a 420 ha census, 568 trees ≥10 cm diameter at breast height (dbh) were counted, resulting in a density of 1.35 trees ha⁻¹. Based on the nearest-neighbor method, an index of aggregation (R) of 0.77 indicated a rejection of the null hypothesis of a strictly random distribution pattern. Yet, this value suggests a much greater tendency toward randomness than either clumping or uniformity. Our data do not show the commonly reported existence of groves, referring to clearly defined clusters of 50 to several hundred trees separated from similar clusters by great distances. Almost 1/4 of the population (23%) was composed of non-reproductive juveniles. Maximum R² improvement analysis applied to four distinct diameter classes provided insight into the dynamics of production-related variables over the species life cycle. While dbh explained 1/3 of production variance (R² = 0.3360) in the smallest diameter class (10 cm ≤ dbh < 50 cm), which included those in the process of reaching reproductive maturity, crown form best explained production variance of very large trees (dbh ≥ 100 cm). Results also demonstrated a significant negative correlation between crown vine load and production of trees ≥ 50 cm dbh (r = −0.13, P = 0.008), suggesting the need for further study on vine cutting as a possible silvicultural treatment for enhancing nut yields.     

A potent acetylcholinesterase inhibitor from Pancratium illyricum L.

Plants belonging to the Amaryllidaceae contain an exclusive group of alkaloids, known as sources of important biological activities. In the present work, Pancratium illyricum L., a species belonging to this family and endemic of Sardinia (Italy), was investigated for its alkaloid content. Fresh bulbs and leaves were processed separately. Standard extraction and purification procedures were applied to obtain fractions and compounds for GC–MS and NMR analysis. In addition to eight already known alkaloids (1–8), 11α-hydroxy-O-methylleucotamine (9) was isolated for the first time and its structure completely determined by one and two-dimensional ¹H and ¹³C NMR spectroscopy. This new galanthamine-type compound exhibited a pronounced in vitro acetylcholinesterase (AChE) inhibitory activity (IC₅₀ = 3.5 ± 1.1 μM) in comparison to the reference standard galanthamine hydrobromide (IC₅₀ = 1.5 ± 0.2 μM).     

Genotype × environment interactions in selected loblolly and slash pine plantations in the Southeastern United States

Few studies have quantified the combined effects of silvicultural treatments and genetic improvement on unit area production of full-sib family blocks of loblolly (Pinus taeda L.) and slash pine (P. elliottii Engelm. var. elliotttii). Efficient operational deployment of genetic materials requires an understanding of possible site and silvicultural treatment interactions to maximize yield potential. We examined genotype (family) by environmental interactions (G × E) through age 5 years using a factorial experiment consisting of silvicultural treatment intensity (operational versus intensive), planting density (1334 versus 2990 trees ha⁻¹) and families (seven elite full-sib loblolly and six elite full-sib slash pine families). In January of 2000, randomized complete block, split-plot experiments were installed at two locations for each species in southeast Georgia and northeast Florida. Five years after planting, both loblolly and slash pine demonstrated significant interactions among several factors: genotype × location (p < 0.028 and p < 0.016, respectively), genotype × silvicultural treatment intensity (p < 0.055 and p < 0.059), and silvicultural treatment intensity × density (p < 0.002 and p < 0.001) for basal area (BA) and standing stem volume (VOL). Genotype × silvicultural treatment interactions were positive, with the best overall performing families responding the greatest to intensive treatment. There were changes in slash pine family rankings between locations, which were partly explained by reductions in growth associated with a combination of fusiform rust infection [Cronartium quercum (Berk.) Miyabe ex Shirai f. sp. fusiforme] and wind damage from the 2004 hurricane season. No three-way interactions, which included family, were evident and all genetic sources were stable across the contrasting planting densities. At age 5, loblolly pine outperformed slash pine (p < 0.0001), especially under the intensive silvicultural intensity. While loblolly performance was similar whether deployed in mixtures or pure family blocks, slash pine tended to be more productive in intimate mixtures than when grown in pure family blocks (p = 0.0754 for aboveground biomass).     

Estimation of biomass and net primary productivity of major planted forests in China based on forest inventory data

Reforestation and afforestation have been suggested as an important land use management in mitigating the increase in atmospheric CO₂ concentration under Kyoto Protocol of UN Framework Convention on climate change. Forest inventory data (FID) are important resources for understanding the dynamics of forest biomass, net primary productivity (NPP) and carbon cycling at landscape and regional scales. In this study, more than 300 data sets of biomass, volume, NPP and stand age for five planted forest types in China (Larix, Pinus tabulaeformis, Pinus massoniana, Cunninghamia lanceolata, Pouulus) from literatures were synthesized to develop regression equations between biomass and volume, and between NPP and biomass, and stand age. Based on the fourth FID (1989–1993), biomass and NPP of five planted forest types in China were estimated. The results showed that total biomass and total NPP of the five types of forest plantations were 2.81 Pg (1 Pg = 10¹⁵ g) and 235.65 Mg ha⁻¹ yr⁻¹ (1 Mg = 10⁶ g), respectively. The area-weighted mean biomass density (biomass) and NPP of different forest types varied from 44.43 (P. massoniana) to 146.05 Mg ha⁻¹ (P. tabulaeformis) and from 4.41 (P. massoniana) to 7.33 Mg ha⁻¹ yr⁻¹ (Populus), respectively. The biomass and NPP of the five planted forest types were not distributed evenly across different regions in China. Larix forests have the greatest variations in biomass and NPP, ranging from 2.7 to 135.37 Mg ha⁻¹ and 0.9 to 10.3 Mg ha⁻¹ yr⁻¹, respectively. However, biomass and NPP of Populus forests in different region varied less and they were approximately 50 Mg ha⁻¹ and 7–8 Mg ha⁻¹ yr⁻¹, respectively. The distribution pattern of biomass and NPP of different forest types closely related with stand ages and regions. The study provided not only with an estimation biomass and NPP of major planted forests in China but also with a useful methodology for estimating forest carbon storage at regional and global levels.     

Modulation of COX,LOX and NFκB activities by Xanthium spinosum L. root extract and ziniolide

Xanthium spinosum L. (Asteraceae) is a medicinal weed distributed worldwide. Many of its diverse ethnopharmacological uses – namely diarrhoea, inflammation, liver disorders, snake bite and fever – are linked – at least in part – to an uncontrolled release of arachidonic acid metabolites. The crude extract of X. spinosum roots from Jordanian origin dose-dependently inhibited the 5-LOX (IC₅₀ ≅ 10 μg/mL), COX-1(IC₅₀ ≅ 50 μg/mL), and 12-LOX (IC₅₀ ≅ 170 μg/mL) enzymatic pathways in intact pro-inflammatory cells. A direct activity at the level of PLA₂ is not probable, but the extract induced the synthesis of the anti-inflammatory eicosanoid 15(S)-HETE, which may in turn inhibit this enzyme. 5-LOX bioguided fractionation of the crude extract led to the isolation of ziniolide, a known 12,8-guaianolide sesquiterpene lactone, from the hydro-alcoholic fraction of the n-hexane extract (IC₅₀ = 69 μM). Both the plant extract and ziniolide are in vitro inhibitors of the phorbol-induced NFκB activation, a key regulator of the arachidonic pathway.     

Improving permeability and oral absorption of mangiferin by phospholipid complexation

Mangiferin is an active ingredient of medicinal plant with poor hydrophilicity and lipophilicity. Many reports focused on improving aqueous solubility, but oral bioavailability of mangiferin was still limited. In this study, we intended to increase not only solubility, but also membrane permeability of mangiferin by a phospholipid complexation technique. The new complex's physicochemical properties were characterized in terms of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), infrared absorption spectroscopy (IR), aqueous solubility, oil–water partition coefficient and in vitro dissolution. The intestinal absorption of the complex was studied by the rat in situ intestinal perfusion model. After oral administration of mangiferin–phospholipid complex and crude mangiferin in rats, the concentrations of mangiferin were determined by a validated RP-HPLC method. Results showed that the solubility of the complex in water and in n-octanol was enhanced and the oil–water partition coefficient was improved by 6.2 times and the intestinal permeability in rats was enhanced significantly. Peak plasma concentration and AUC of mangiferin from the complex (C_max: 377.66 μg/L, AUC: 1039.94 μg/L*h) were higher than crude mangiferin (C_max: 180 μg/L, AUC: 2355.63 μg/L*h). In view of improved solubility and enhanced permeability, phospholipid complexation technique can increase bioavailability of mangiferin by 2.3 times in comparison to the crude mangiferin.     

Estrogenic and anti-estrogenic activities of hispolon from Phellinus lonicerinus (Bond.) Bond. et sing

Hispolon was the main antitumor active ingredient in Phellinus sensu lato species. In order to confirm the dual regulating estrogenic ingredient and obtain more effective natural estrogen replacement drugs, hispolon was separated from Phellinus lonicerinus (Bond.) Bond. et sing. Hispolon exhibited significant anti-proliferative effect against estrogen-sensitive ER (+) MCF-7 cells in the absence of estrogen, and exhibits antagonistic effects on 17β-estradiol (E₂)-induced MCF-7 cell proliferation when E₂ and the different concentrations of hispolon were treated simultaneously. Hispolon also inhibited the proliferation of estrogen-negative ER (−) MDA-MB-231 cells at the concentration of 5.00 × 10^− 5 M. The yeast two-hybrid experiments showed that hispolon had strong and non-selective effects on the estrogen receptor (ER) α and ERβ at a concentration of 1.00 × 10^− 6 M. The ERβ-binding ability of hispolon was larger than ERα in the concentration range of 1.00 × 10^− 9 M and 1.00 × 10^− 7 M. Hispolon could increase the body weight coefficient, serum E₂ and progesterone contents in immature female mice at dose of 9.10 × 10^− 6 mol/kg, and increase coefficient of thymus and spleen in mice. The Gscores of hispolon-ERα and hispolon-ERβ docked complexes were − 7.93 kcal/mol and − 7.79 kcal/mol in docking simulations. Hispolon presented dual regulating estrogenic activities, which showed estrogenic agonist activity at low concentration or lack of endogenous estrogen, and the estrogenic antagonistic effect was stimulated at high concentrations or too much endogenous estrogen. Hispolon could be used for treating the estrogen deficiency-related disease with the benefit of non-toxic to normal cells, good antitumor effects and estrogenic activity.     

Simulation of carbon and water budgets of a Douglas-fir forest

The forest growth/hydrology model FORGRO–SWIF, consisting of a forest growth and a soil water model, was applied to quantify the inter-annual variability of the carbon and water budgets of a Douglas-fir forest (Pseudotsuga menziessii (Mirb.) Franco) in The Netherlands. With these budgets, the water use efficiency, the amount of water needed to fix a certain amount of carbon, and its variability was estimated. After testing the model performance in simulating daily carbon and transpiration fluxes, and soil water contents of this forest ecosystem, the model was applied to a 10-year period of meteorological data. Two forest parameterisations were used: the non-thinned situation of 1995, and the thinned situation in 1996. Relations between forest water use and forest growth were quantified with the model. The model performed satisfactory, an R² value for daily carbon fluxes of 0.58 and for daily transpiration fluxes 0.81. The forest showed to be a clear carbon sink, in the climax situation between 1000 and 1210 g C m⁻² per year. In the thinned situation the carbon uptake was more than halved to values between 430 and 620 g C m⁻² per year. The calculated yearly WUE’s for the forest were between 2.5 and 4.3 g C m⁻² mm⁻¹ and for the total ecosystem between 1.1 and 2.0 g C m⁻² mm⁻¹. The thinned forest had clearly lower WUE’s than the non-thinned forest. The importance of including interception evaporation as forest water use is discussed, and the results showed the importance of integration of forest growth and forest water use for calculating yearly carbon and water budgets.     

Identification of chicoric acid as a hypoglycemic agent from Ocimum gratissimum leaf extract in a biomonitoring in vivo study

Ocimum gratissimum L. is popularly used to treat diabetes mellitus. The hypoglycemic activity of this medicinal species has been confirmed by in vivo studies. The present study conducted a chemical investigation of a leaf decoction (10% p/v) of O. gratissimum monitored by in vivo hypoglycemic activity assays. Four phenolic substances were identified: l-caftaric acid (1), l-chicoric acid (2), eugenyl-β-d-glucopyranoside (3) and vicenin-2 (4). The acute hypoglycemic activity of the O. gratissimum decoction fractions Og1-S (300 mg/kg), Og1-A (240 mg/kg) and Og1-B (80 mg/kg) was evaluated intraperitoneally in normal and streptozotocin-induced diabetic mice. They reduced glycemia by 63%, 76% and 60% (in 120 min), respectively, in the diabetic mice. Subfractions of Og1-A were also evaluated under the same conditions: Og1-AS (200 mg/kg) and Og1-AP (40 mg/kg) produced a decrease of only 37% and 39%, respectively. Among the major phenolic substances, only chicoric acid (2; 3 mg/kg) reduced significantly the glycemic levels of diabetic mice by 53%, 120 min after treatment. This is the first study describing the hypoglycemic activity of chicoric acid in an animal model of diabetes mellitus. In addition, we suggest that there may be other substances contributing to this activity. Thus, for the first time, a correlation is established between the hypoglycemic activity of O. gratissimum and its chemical composition.     

Protection of chronic renal failure by a polysaccharide from Cordyceps sinensis

A water-soluble polysaccharide (CPS-2), isolated from the cultured Cordyceps sinensis, was obtained by hot-water extraction, anion-exchange and gel permeation chromatography. Its structural characteristics were investigated by PMP pre-column derivation, periodate oxidation, methylation analysis, FTIR and NMR spectroscopy. CPS-2 was found to be mostly of α-(1 → 4)-d-glucose and α-(1 → 3)-D-mannose, branched with α-(1 → 4,6)-d-glucose every twelve residues on average. CPS-2 had a molecular weight of 4.39 × 10⁴ Da. The protective effect of CPS-2 on the model of chronic renal failure was established by fulgerizing kidney. The changes in blood urea nitrogen and serum creatinine revealed that CPS-2 could significantly relieve renal failure caused by fulgerizing kidney.     

Tree and forest encroachment into fescue grasslands on the Cypress Hills plateau,southeast Alberta,Canada

Tree encroachment into rough fescue (Festuca campestris) grassland has been identified as an ecological concern on the Cypress Hills plateau in southeastern Alberta, Canada. A combination of field sampling (109 transects), a dendrochronological assessment (1361 trees), and a time series analysis of remotely sensed images from five different time periods (1950–2002) were used to determine the extent and rate of tree encroachment and forest development. Tree cover increased by 768 ha (～51%) between 1950 and 2007, representing 10% of the study area, from 1502 ha of pre-1950 forest. Post-1950 tree invasion also created an ingress zone of 750 ha (～10% of study area) based on field transects. Forest cover increased at a consistent rate of 14.3 ha/year. Lodgepole pine (Pinus contorta var. latifolia) was the most common tree species associated with encroachment. Invasion based on the number of established trees occurred at an exponential rate of 3.1%/year after 1890, with density increased by filling spaces adjacent to and between trees within the grassland vegetation. The rate of tree establishment increased to 4.4%/year after 1980, suggesting a change occurred in environmental conditions. Annual atmospheric temperatures increased 0.55 °C from 1929 to 2005 (P < 0.001), with winter (December–February) and spring (March–May) temperatures accounting for most of the increase (P < 0.001), whereas summer (June–August) temperatures slightly decreased (P < 0.050, 0.34 °C) and precipitation increased (P < 0.005, 30 mm). Cattle and elk (Cervus elaphus) grazing was not considered a primary factor for explaining tree encroachment. Based on multidimensional scaling, lodgepole pine establishment was associated with warmer spring temperatures and greater fall (October–November) precipitation. A landscape devoid of wildfires, combined with greater moisture availability, and a longer frost-free season is likely conducive to the sustained establishment of coniferous trees and forest development within the Cypress Hills fescue grassland ecosystem. Long-term conservation of the fescue grasslands could be possible by reintroducing fire.