人工林马尾松木材性质的变异

本文研究了广西人工林马尾松木材性质的变异及幼龄材与成熟材的差异。结果表明 ,幼龄材与成熟材的分界年龄在 14　 16a ,解剖性质在径向上的变异规律为 :射线比量、树脂道比量、胞壁率、胞腔直径、胞壁厚、管胞长度、管胞宽度和晚材壁腔比是自髓心向外呈递增趋势 ,管胞比量和晚材率为递减趋势 ,早材壁腔比和早材腔径比则近似于一条直线。方差分析结果表明 :树脂道比量、胞壁率、胞壁厚、管胞长度和管胞宽度 ,幼龄材与成熟材差异达显著或极显著水平。 5项木材物理力学性质均为成熟材高于幼龄材 ,且均达差异显著水平。木材性质间的相关分析表明 :木材基本密度与管胞长度、管胞宽度、射线比量、树脂道比量、胞壁率呈显著的正相关关系 ,木材气干密度与抗弯强度、抗弯弹性模量、顺纹抗压强度也呈显著的正相关关系     

Verbascoside isolated from Tectona grandis mediates gastric protection in rats via inhibiting proton pump activity

Evidences have suggested that Tectona grandis (TG) attenuates gastric mucosal injury; however its mechanism has not yet been established. The aim of present study was to evaluate the gastroprotective mechanism of ethanolic extract of TG (E-EtOH), butanolic fraction (Fr-Bu) and to identify its active constituents. Anti-ulcer activities were evaluated against cold restraint (CRU) and pyloric ligation (PL) induced gastric ulcer models and further confirmed through H⁺ K⁺-ATPase inhibitory activity. Cytoprotective activity was evaluated in alcohol (AL) induced gastric ulcer model and further through PGE₂ level. E-EtOH and Fr-Bu attenuated ulcer formation in CRU. Moreover E-EtOH and Fr-Bu displayed potent anti-secretory activity as evident through reduced free acidity and pepsin activity in PL, confirmed further by in vitro inhibition of H⁺ K⁺-ATPase activity. In addition cytoprotective potential of E-EtOH and Fr-Bu were apparent with protection in AL model, increased PGE₂ content and enhanced mucin level in PL. Phytochemical investigations of Fr-Bu yielded terpenoides and a phenolic glycoside, verbascoside. The anti-secretory mechanism of verbascoside mediated apparently through inhibition of H⁺ K⁺-ATPase with corresponding decrease in plasma gastrin level, is novel to our finding. Gastroprotection elicited by TG might be through proton pump inhibition and consequent augmentation of the defensive mechanism.     

Changes of plasma membrane H<Superscript>+</Superscript>-ATPase activities of <Emphasis Type="Italic">Glycine max</Emphasis> seeds by PEG treatment

The soybean （Glycine max） Heihe No. 23 is sensitive to imbibitional chilling injury. Polyethylene glycol （PEG） treatment can improve chilling tolerance of soybean seeds to a certain extent. The changes of hydrolytic ATPase in plasma membranes and H^＋-pumping responses in soybean seeds were investigated during PEG treatments. Effects of exogenous calcium and exogenous ABA on the hydrolytic ATPase were also examined in order to understand the mechanism of chilling resistance. Highly purified plasma membranes were isolated by 6.0% aqueous two-phase partitioning from soybean seeds, as judged by the sensitivity of hydrolytic ATPase to sodium vanadate. PEG treatment resulted in a slight increase of the hydrolytic ATPase activity in 12 h. Then the activity decreased gradually, but still higher than the control. The H^＋-pumping activity increased steadily during PEG treatment. Exogenous calcium had both activating and inhibiting effects on the hydrolytic ATPase, but the activity was inhibited in soybean seeds treated with exogenous ABA. Results suggested that PEG treatment, not the exogenous calcium and ABA, up-regulated H^＋-ATPase activities in soybean seeds.     

The effect of berberine in vitro on tight junctions in human Caco-2 intestinal epithelial cells

Berberine is one of the main alkaloids of Rhizoma coptidis which has been used for patients with gastrointestinal disorders. The major aim of this study was to investigate the effect of berberine on tight junction. Caco-2 cells were treated with various concentration of berberine. We observed the integrity of tight junction by measuring the transepithelial electrical resistance (TEER), and also studied the effect of berberine on morphology of tight junction and tight junction protein. These findings showed the first time that berberine could reduce epithelial gut permeability, and might help explain the possible mechanisms of anti-diarrhea activity of berberine.     

Suppression of beta-naphthoflavone induced CYP1A expression and lipid-peroxidation by berberine

Impacts of berberine, a major isoquinoline alkaloid in herbal plants, on beta-naphthoflavone (BNF)-induced CYP1A expression were determined both in primary mouse hepatocytes and in vivo. Berberine concentration-dependently suppressed BNF-induced CYP1A expression in mouse hepatocyte and it significantly down-regulated BNF-induced CYP1A in mouse liver via suppression of mRNA and protein expression, and decreases of EROD and MROD activities. Moreover, berberine showed significant potential on suppression of BNF-induced lipid peroxidation in mouse hepatic microsome. Therefore, using berberine as a health supplement or an alternative medication might provide extra-benefit due to its inhibitory regulation on CYP1A expression and anti-lipid peroxidation activity.     

几种作用因子对多年生黑麦草组织培养影响的研究

以多年生黑麦草成熟种子为外植体进行了愈伤组织诱导和分化的研究。结果表明:dicamba替代2,4 D,蔗糖替代麦芽糖可以显著提高愈伤组织诱导率和植株再生率;在一定的浓度范围内(3～9mg·L-12,4 D)2,4 D浓度的升高可明显提高愈伤组织的诱导率,但同时却降低了分化率;在愈伤诱导培养基中同时使用两种生长激素(2,4 D和NAA)的效果要好于单独使用一种生长激素(2,4 D)的效果;水解酪蛋白、脯氨酸和谷氨酰胺浓度的增加并没有促进植株再生率的升高。     

Cytotoxicity and antihyperglycemic effect of minor constituents from Rhizoma Coptis in HepG2 cells

Generally, berberine, coptisine, palmatine, and jatrorrhizine were considered as the main bio-active compounds in Rhizoma Coptis (RC). Little attention was paid to investigate the pharmacological activity of minor constituents in RC. The present study was designed to separate the minor compounds, and the cytotoxicity and antihyperglycemic effect of these compounds in HepG2 cells were also studied. Palmatine (1), berberine (2), coptisine (3), epiberberine (4), columbamine (5), and jatrorrhizine (6) from RC ethanol extract were isolated by high speed counter current chromatography (HSCCC) in one run. The remaining fraction (about 50% of extract in HSCCC) was further isolated by traditional column chromatography methods to yield magnoflorine (7), ferulic acid (8), and choline (9). Another four alkaloids, namely groenlandicine (10), berberrubine (11), oxyberberine (12), 8-oxo-coptisine (13), also were obtained from CHCl₃ extracts. Especially, choline was first isolated from RC. Cell assay indicated that the minor fractions excluding compounds 1-6 showed obvious glucose lowering activity. In addition, the minor monomers also exhibited moderate glucose lowering activity. The combination of berberine and ferulic acid showed synergistic effect on antihyperglycemic. The combination of alkaloids 1-6 was same so. All compounds had different cytotoxicity in HepG2 cells within the test concentration. Of them, berberrubine showed the strongest cytotoxicity. The results suggested that combined action of variety constituents contributed to the antihyperglycemic effets and low cytotoxicity of RC extract in HepG2 cells.     

Evaluation of aerosol devices for simultaneous disruption of sex pheromone communication in <Emphasis Type="Italic">Cydia pomonella</Emphasis> and <Emphasis Type="Italic">Grapholita molesta</Emphasis> (Lepidoptera: Tortricidae)

A two-year study was conducted evaluating Puffer^® aerosol dispensers (Suterra LLC, Bend, OR, USA) for mating disruption of codling moth, Cydia pomonella (L.), and the oriental fruit moth, Grapholita molesta (Busck). The Puffer^® dispenser consists of a pressurized metal canister loaded with pheromone active ingredients dissolved in solvent and housed within a circuit-controlled, plastic dispensing cabinet programmed to release an aerosol spray of pheromone at regular intervals. Puffers^® were deployed at the label-recommended rate of 2.5 ha^?1 and released ca. 5–10 mg of pheromone (depending on treatment) per 15 min during a 12-h cycle beginning each day at 15:00 h for the duration of the season. In 2005, commercially-managed apple plots (3.2–4.9 ha) were treated with Puffers^® releasing both species’ pheromone simultaneously (dual-species) or with twice the number of adjacently-deployed Puffers^® (4–6 m apart) releasing each individual species’ pheromones (single-species), while maintaining comparable overall release rates of pheromone between these two treatments. Plots 100 m away and not treated with pheromone served as the control. Disruption of male C. pomonella and G. molesta orientation to pheromone-baited traps was 46–75 and 91–98%, respectively, in Puffer^®-treated plots compared with untreated controls. There was no statistical difference in moth disruption between plots treated with dual-species and single-species Puffers^®. Fruit injury was not statistically different between Puffer^®-treated plots and control plots not receiving pheromone. In 2006, disruption of male moth orientation to traps was 24–26 and 84–97% in Puffer^®-treated plots (2.9–5.7 ha) for C. pomonella and G. molesta, respectively, compared with untreated controls. During this season, fruit injury was lower in pheromone-treated plots compared with untreated controls at mid-season, but not at pre-harvest. Combining the pheromone of both species into single Puffer^® units did not decrease efficacy of disruption compared with deploying twice as many Puffers^® releasing a similar amount of each individual species’ pheromone suggesting that multi-species disruption using Puffers^® is a viable option. However, we conclude that the efficacy of disruption attained with low-densities (2.5 ha^?1) of Puffers^® at the moth densities recorded in this study is insufficient for effective control of C. pomonella without input of companion insecticides.     

Active root distribution pattern of <Emphasis Type="Italic">Hevea brasiliensis</Emphasis> determined by radioassay of latex serum

The active root distribution pattern of mature rubber (Hevea brasiliensis Muell. Arg.) up to a lateral distance of 250 cm from the tree and to a soil depth of 90 cm was studied in an oxisol by employing ³²P soil injection technique in Kerala, the state which accounts for 83% of rubber cultivation in India. The trees were aged 18 years and grown at a spacing of 4.9 × 4.9 m. The extent of absorption of applied ³²P by the tree from various placements was assessed by radio assay of leaf and latex serum. Latex serum registered higher counts and variability was less compared to leaf indicating the suitability of latex serum as a potential source for radio assay for ³²P studies in rubber. The results revealed that rubber is a surface feeder with 55% of the root activity confining to the top 10 cm of soil layer. Root activity declined with increasing depths and the concentration of physiologically active roots at 90 cm depth was only 6%. A more or less uniform distribution of root activity was noticed with respect to lateral distance indicating more extensive spread of lateral roots. Concentration of physiologically active roots in the surface layer suggests the possibility for competition under intercropped situation in mature plantations.     

Root distribution pattern of the wild jack tree (Artocarpus hirsutus Lamk.) as studied by 32P soil injection method

Root distribution of the wild jack tree (Artocarpus hirsutus) was determined by selective placement of ³²P at various depths and lateral distances from the tree, in Kerala, India. In eight-and-a-half-year-old trees growing on a lateritic site, absorption of ³²P from a lateral distance of 75 cm and 30 cm depth was much greater than from 150 and 225 cm lateral distance and 60 and 90 cm depth. Root activity declined with increasing depth and lateral distance. Most of the physiologically active roots were concentrated within a radius of 75 cm and 30 cm depth, although the tap root might reach even deeper. Possibly, surface accumulation of feeder roots may cause considerable overlap of the tree and crop root zones in intercropping situations. However, as the tree roots seldom extend beyond 2.25 m laterally from the trunk, the effect of overlapping root zones and the associated competitive effects may not be a serious problem for intercropping during the first few years (<10 years after planting) of tree growth.     

Tracing the fate of mineral N compounds under high ambient N deposition in a Norway spruce forest at Solling/Germany

The fate of high and equally distributed ammonium and nitrate deposition was followed in a 72-year-old roofed Norway spruce forest at Solling in central Germany by separately adding ¹⁵NH₄⁺ and ¹⁵NO₃⁻ to throughfall water since November 2001. The objective was to quantify the retention of atmospheric ammonium and nitrate in different ecosystem compartments as well as the leaching loss from the forest ecosystem. δ¹⁵N excess in tree tissues (needles, twigs, branches and bole woods) decreased with increased tissue age. Clear ¹⁵N signals in old tree tissues indicated that the added ¹⁵N was not only assimilated to newly produced tree tissues but also retranslocated to old ones. During a period of over 3-year ¹⁵N addition, 30% of ¹⁵NH₄⁺ and 36% of ¹⁵NO₃⁻ were found in tree compartments. For both ¹⁵N tracers, 15% of added ¹⁵N was found in needles, followed by woody tissues (twigs, branches and boles, 7–13%) and live fine roots (7%). The recovery of ¹⁵NH₄⁺ and ¹⁵NO₃⁻ in the live fine roots differed with soil depth. The recovery of ¹⁵NH₄⁺ tended to be higher in the live fine roots in the organic layer than in the upper mineral soil. In the live fine roots in deeper soil, the recovery of ¹⁵NO₃⁻ tended to be higher than that of ¹⁵NH₄⁺. Soil retained the largest proportion of ¹⁵N, accounting for 71% of ¹⁵NH₄⁺ and 42% of ¹⁵NO₃⁻. Most of ¹⁵NH₄⁺ was recovered in the organic layer (65%) and the recovery decreased with soil depth. Conversely, only 8% of ¹⁵NO₃⁻ was found in the organic layer and 34% of ¹⁵NO₃⁻ was evenly distributed throughout the mineral soil layers. Nitrate leaching accounted for 3% of ¹⁵NH₄⁺ and 19% of ¹⁵NO₃⁻. Only less than 1% of the both added ¹⁵N was leached as DON. These results suggested that trees had a high contribution to the retention of atmospheric N and soil retention capacity determined the loss of atmospheric N by nitrate leaching.     

Activity of Berberis aetnensis root extracts on Candida strains

The antifungal activity of methanolic extract and alkaloidal fraction of Berberis aetnensis against Candida species was investigated. The crude extract was active against Candida species, this activity being higher than that of the alkaloidal fraction and berberine.     

粤北石漠化地区土壤侵蚀的137Cs法研究

据2005年10月的野外调查及对TM卫星影像解译分析结果,研究了粤北不同程度的石漠化地区、不同利用类型土地的¹³⁷Cs区域分布以及土壤侵蚀速率特征。结果表明:粤北石漠化地区土壤¹³⁷Cs活度的平均值为(6.54±0.57) Bq·kg^-1,土壤中¹³⁷Cs水平随石漠化程度增加有先降低然后升高的趋势,表明在重度石漠化阶段,过高的基岩裸露率导致其周围土壤对¹³⁷Cs的集中吸附,¹³⁷Cs在某些沉积小环境内逐渐富集。研究区¹³⁷Cs背景值为(1 433.60±131.40) Bq·m^-2,低于北半球的平均值,¹³⁷Cs剖面分布基本符合指数分布,最高值出现在2~4 cm深度范围内。在轻度、中度石漠化地区,非耕作土壤侵蚀速率的平均值分别为1 369.0、1 833.5 t·km^-2·a^-1;耕作土壤侵蚀速率远高于非耕作土壤,坡度对土壤侵蚀影响非常明显。     

Soil N cycling in old-growth forests across an Andosol toposequence in Ecuador

Nitrogen (N) deposition in the tropics is predicted to increase drastically in the next decades. The sparse information on N cycling in tropical forests revealed that the soil N status of an ecosystem is the key to analyze its reactions to projected increase in N input. Our study was aimed at (1) comparing the soil N availability of forest sites across an Ecuadorian Andosol toposequence by quantifying gross rates of soil N cycling in situ, and (2) determining the factors controlling the differences in soil N cycling across sites. The toposequence was represented by five old-growth forest sites with elevations ranging from 300 m to 1500 m. Our results provide general insights into the role of elevation-mediated factors (i.e. degree of soil development and temperature) in driving patterns of soil N cycling. Gross rates of N transformations, microbial N turnover time, and δ¹⁵N signatures in soil and leaf litter decreased with increasing elevation, signifying a decreasing N availability across the toposequence. This was paralleled by a decreasing degree of soil development with increasing elevation, as indicated by declining clay contents, total C, total N, effective cation exchange capacity and increasing base saturation. Soil N-cycling rates and δ¹⁵N signatures were highly correlated with mean annual temperature but not with mean annual rainfall and soil moisture which did not systematically vary across the toposequence. Microbial immobilization was the largest fate of produced NH₄⁺ across all sites, and nitrification activity was only 5–11% of gross NH₄⁺ production. We observed a fast reaction of NO₃⁻ to organic N and its role for N retention deserves further attention. If projected increase in N deposition will occur, the timing and magnitude of gaseous N losses may follow the pattern of N availability across this Andosol toposequence.     

Bamboo hedgerow systems in Kerala, India: Root distribution and competition with trees for phosphorus

In a field study on bamboo (Bambusa arundinacea (Retz.) Willd.) hedgerow systems of Kerala, we tested the following three hypotheses: (1) Effective root foraging space is a function of crown spread, (2) Proximity of trees depress lateral spread of roots in mixed species systems and (3) The closer the trees are located the greater will be the subsoil root activity which in turn facilitates active absorption of nutrients from deeper layers of the soil profile. Root distribution of boundary planted bamboo and root competition with associated trees in two binary mixtures, teak (Tectona grandis)-bamboo and Malabar white pine (Vateria indica)-bamboo, were evaluated using modified logarithmic spiral trenching and ³²P soil injection techniques respectively. Excavation studies indicate that rooting intensity declined linearly with increasing lateral distance. Larger clumps manifested wider foraging zones. Eighty three per cent of the large clumps (>4.0 m dia.) extended roots beyond 8 m while only 33% of the small (<2.5 m dia.) clumps extended roots up to 8 m. Highest root counts were found in the 10–20 cm layer with nearly 30% of total roots. Although nearness of bamboo clumps depressed root activity of teak and Vateria in the surface layers of the soil profile, root activity in the deeper layers was stimulated. ³²P recovery was higher when applied at 50-cm depth than at 25-cm depth implying the safety net role of tree roots for leached down nutrients. Inter specific root competition can be regulated by planting crops 8–9 m away from the bamboo clumps and/or by canopy reduction treatments. This revised version was published online in June 2006 with corrections to the Cover Date.     

Supramolecular phospholipids–polyphenolics interactions: The PHYTOSOME® strategy to improve the bioavailability of phytochemicals

The poor and/or erratic oral bioavailability of polyphenolics can be improved using the PHYTOSOME^®1 delivery system, a strategy that enhances the rate and the extent of solubilization into aqueous intestinal fluids and the capacity to cross biomembranes. Phospholipids show affinity for polyphenolics, and form supramolecular adducts having a definite stoichiometry. This article reviews the preparation and characterization of PHYTOSOME^® complexes and their activity in various medicinal (cardiovascular, anti-inflammatory, hepatoprotective, anticancer) and cosmetic (skin aging) realms of application.     

Proton translocating ATPase mediated fungicidal activity of eugenol and thymol

Eugenol (1) and thymol (2) exhibit excellent fungicidal activity against pathogenic yeasts, including isolates resistant to azoles. The rapid irreversible action of compound-1 and compound 2 on fungal cells suggested a membrane-located target for their action. We investigated their effect on H⁺-ATPase mediated H⁺-pumping by various Candida species. Both compounds inhibit H⁺-ATPase activity at their respective MIC values — 500 and 100 μg/ml. Glucose stimulated H⁺-extrusion was also inhibited significantly by compound 1 and compound 2. Inhibition of H⁺-ATPase leads to intracellular acidification and cell death. Inhibition of cell growth and H⁺-efflux by test compounds suggests that their antifungal properties are related to their inhibitory effects on H⁺-ATPase.