Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Aesculus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed2003

Differences in leaf phenology between juvenile and adult trees in a temperate deciduous forest.

In a deciduous forest, differences in leaf phenology between juvenile and adult trees could result in juvenile trees avoiding canopy shade for part of the growing season. By expanding leaves earlier or initiating senescence later than canopy trees, juvenile trees would have some period in high light and therefore greater potential carbon gain. We observed leaf phenology of 376 individuals of 13 canopy tree species weekly over 3 years in a deciduous forest in east central Illinois, USA. Our objectives were: (1) to quantify for each species the extent of differences in leaf phenology between juvenile and conspecific adult trees; and (2) to determine the extent of phenological differences between juvenile Aesculus glabra Willd. and Acer saccharum Marsh. trees in understory and gap microhabitats. All species displayed phenological differences between life stages. For 10 species, bud break was significantly earlier, by an average of 8 days, for subcanopy individuals than for canopy individuals. In 11 species, completion of leaf expansion was earlier, by an average of 6 days, for subcanopy individuals than for canopy individuals. In contrast, there were no significant differences between life stages for start of senescence in 10 species and completion of leaf drop in nine species. For eight species, leaf longevity was significantly greater for subcanopy individuals than for canopy individuals by an average of 7 days (range = 4-10 days). Leaf phenology of subcanopy individuals of both Aesculus glabra and Acer saccharum responded to gap conditions. Leaf longevity was 11 days less in the understory than in gaps for Aesculus glabra, but 14 days more in the understory than in gaps for Acer saccharum. Therefore, leaf phenology differed broadly both between life stages and within the juvenile life stage in this community. A vertical gradient in temperature sums is the proposed mechanism explaining the patterns. Temperature sums accumulated more rapidly in the sheltered understory than in an open elevated area, similar to the canopy. Early leaf expansion by juvenile trees may result in a period of disproportionately higher carbon gain, similar to gains made during summer months from use of sun flecks.

Acer↗
PubMed2002

Water and oxygen permeance of phellems isolated from trees: the role of waxes and lenticels.

The outermost phellems of Abies alba Mill., Acer pseudoplatanus L., Aesculus hippocastanum L., Betula potaninii L.C. Hue and Sambucus nigra L. have been isolated enzymatically, resulting in membranes with five to seven heavily suberized cork cell layers. Water and oxygen permeances were determined for the phellem areas without lenticels. A special diaphragm made it possible to quantify permeances of single lenticels for the first time. The water permeance of phellems was in the range of 3x10(-5) to 9x10(-5) ms(-1) and can be predicted from the density of the phellem membranes with 93% accuracy. Embedded waxes amounted to 3% ( Aesculus) and up to 35% ( Betula) of the dry weight but affected water permeance only to a small degree. The sorption isotherms describing the water content of the phellems in relation to relative humidities followed a hyperbolic shape and indicated varying water contents among plant species. It is argued that water transfer across the phellems occurs via the middle lamellae. Phellem membranes were impermeable to oxygen. Removal of the waxes hardly changed this situation. Single lenticels from Betula and Sambucus were significantly more permeable to water and oxygen than phellem areas without lenticels. The water permeance was elevated by factors of 39 for Betula and 12 for Sambucus, the oxygen permeance by factors of 1,202 for Betula and 53 for Sambucus. Extraction of lenticels did not affect permeance. A quantitative comparison of the gas-exchange capacity of lenticels and stomata demonstrated the superiority of stomata. However, differences may be not more than one order of magnitude.

Abies↗
PubMed1967

Comparative Studies on Plastoquinones. III. Distribution of Plastoquinones in Higher Plants.

The distribution of plastoquinones A 45, B and C was studied in representatives from 34 different plant families beginning with liverworts and mosses to higher plants. All of these species, including many monocots and dicots, contained significant amounts of the 3 quinones. Two species of Aesculus contained plastoquinone A 20 in addition to plastoquinone A 45, B, and C. Many dicots, such as Aesculus, watermelon, tobacco and tomato accumulated increasing quantities of plastoquinones A and C(1)-C(4) during the growing season. The concentrations of plastoquinones B and C(5)-C(6) tended to remain at a constant low level during the season (<0.01 mumole per mg chlorophyll). Preliminary studies with bean plants (Vicia faba and Phaseolus sp.) indicate that the levels of quinones varied little under different growth conditions (day length and temp.) although Vicia faba tended to have higher PQ A values with increased temperature.

Journal Article↗
PubMedDate not supplied

Treatment of patients with venous insufficiency with fresh plant horse chestnut seed extract: a review of 5 clinical studies.

Extracts from the seed of the horse chestnut (Aesculus hippocastanum L.) have traditionally been used to treat patients with chronic venous insufficiency and to alleviate its associated symptoms, including lower leg swelling. The efficacy of preparations that contain horse chestnut seed extract (HCSE) is believed to be due largely to an inhibitory effect on the catalytic breakdown of capillary wall proteoglycans. Aesculaforce is a fresh plant HCSE that is available as an oral tincture, as tablets (20 mg or 50 mg), and as topical gel. Four clinical trials in patients with chronic venous insufficiency and 1 study in patients with varicose veins demonstrated the effectiveness of these preparations through the objective measure of reduction in lower leg edema and the subjective alleviation of leg pain, heaviness, and itching. Safe, well tolerated, and acceptable to patients, the fresh plant HCSE preparation Aesculaforce offers a real alternative in the treatment of patients with mild to moderate venous insufficiency.

Aesculus↗
PubMed2003

Physiology-based phenology models for forest tree species in Germany.

Models of phenology are needed for the projection of effects of a changing climate on, for example, forest production, species competition, vegetation-atmosphere feedback and public health. A new phenology model for deciduous tree bud burst is developed and parameters are determined for a wide geographical range (Germany) and several forest tree species. The new model is based on considerations of simple interactions between inhibitory and promotory agents that are assumed to control the developmental status of a plant. Several alternative model structures were formulated emphasizing different hypothetical physiological processes. The new models fitted the observations better than classical models. The bias of the classical models, i.e. overestimation of early observations and underestimation of late observations, could be reduced but not completely removed. Differences in the best-fitting model equations for each species indicated that, for the late spring phases (bud burst of Fagus sylvatica and Quercus robur), the photoperiod played a more dominant role than for early spring phases (bud burst of Betula pendula and Aesculus hippocastanum). Chilling only plays a subordinate role for spring bud burst compared to temperatures preceding this event in our data. The presented modeling approach allowed for a species-specific weighting of the dominant processes. The model results are in accordance with experimental findings that indicate an important role of day length in late spring BB. Potentials for model improvement are discussed.

Aesculus↗
PubMed2005

Characterization of trace metal particles deposited on some deciduous tree leaves in an urban area.

In 1996 and 1997 horse chestnut (Aesculus hippocastanum L.) and Turkish hazel (Corulys colurna L.) leaves were sampled at 2 m height in the Belgrade Botanic Garden, located in an urban area with heavy traffic. Using a scanning electron microscope with an energy dispersive X-ray spectroscopy (SEM-EDAX), the size, size distribution, morphology and chemical composition of individual particles were examined on the adaxial and abaxial surfaces of leaf discs of both species. The majority of particles observed on leaves belonged to a class of fine particles (D < 2 microm). Morphological and chemical composition indicated that the most abundant particles were soot and dust with minor constituents such as Pb, Zn, Ni, V, Cd, Ti, As and Cu. Using an electrochemical technique (DPASV), it was possible to measure trace metal concentrations (Pb, Cu, Zn) in a water-soluble fraction of deposits on each single leaf. Trace metal contents in the leaf deposits, increased during the vegetation period for both species and were considerably higher in A. hippocastanum due to different epidermal characteristics. The higher trace metal concentrations in deposits in 1997 reflected greater atmospheric pollution in the Belgrade urban area.

Aesculus↗
PubMed2005

Hydrophilic solutes in modified carbon dioxide extraction-prediction of the extractability using molecular dynamic simulation.

Super- and subcritical carbon dioxide (CO2) extractions of crude drugs were simulated by molecular modelling to predict the extractability of different hydrophilic plant constituents under various extraction conditions. The CO2 extraction fluids were simulated either with pure CO2 or with solvent modified CO2 at different pressures and temperatures. Molecular modelling resulted in three different solubility parameters: the total solubility parameter delta and the partial solubility parameters delta(d) for the van der Waals and delta(EL) for the polar forces. Thus, delta(EL) enabled the estimation of the polarity of the extraction fluids and the solute molecules. If the value of delta(EL) of the extraction fluid reached the value of the solute molecule in the crude drug, i.e. minimum extraction value, the compound was soluble at the distinct extraction conditions. For a further increase in yield of the hydrophilic solutes, the polarity of the extraction fluid had to be increased, too. That means delta(EL) of the fluid exceeded the minimum extraction value. All simulations were verified by CO2 extractions of the secondary roots of Harpagophytum procumbens (harpagoside, stachyose) and the seeds of Aesculus hippocastanum (aescin). CO2 extractions of the flowers of Matricaria recutita ((-)-alpha-bisabolol) were obtained from literature data. These four constituents with different properties, like molecular size and the allocation of polar functional groups were extracted, analysed, simulated and the extract content was correlated with the extraction fluid used, respectively.

Aesculus↗
PubMed2006

Beta-escin inhibits colonic aberrant crypt foci formation in rats and regulates the cell cycle growth by inducing p21(waf1/cip1) in colon cancer cells.

Extracts of Aesculus hippocastanum (horse chestnut) seed have been used in the treatment of chronic venous insufficiency, edema, and hemorrhoids. Most of the beneficial effects of horse chestnut are attributed to its principal component beta-escin or aescin. Recent studies suggest that beta-escin may possess anti-inflammatory, anti-hyaluronidase, and anti-histamine properties. We have evaluated the chemopreventive efficacy of dietary beta-escin on azoxymethane-induced colonic aberrant crypt foci (ACF). In addition, we analyzed the cell growth inhibitory effects and the induction of apoptosis in HT-29 human colon cancer cell line. To evaluate the inhibitory properties of beta-escin on colonic ACF, 7-week-old male F344 rats were fed experimental diets containing 0%, 0.025%, or 0.05% beta-escin. After 1 week, the rats received s.c. injections of azoxymethane (15 mg/kg body weight, once weekly for 2 weeks) or an equal volume of normal saline (vehicle). Rats were continued on respective experimental diets and sacrificed 8 weeks after the azoxymethane treatment. Colons were evaluated histopathologically for ACF. Administration of dietary 0.025% and 0.05% beta-escin significantly suppressed total colonic ACF formation up to approximately 40% (P < 0.001) and approximately 50% (P < 0.0001), respectively, when compared with control diet group. Importantly, rats fed beta-escin showed dose-dependent inhibition (approximately 49% to 65%, P < 0.0001) of foci containing four or more aberrant crypts. To understand the growth inhibitory effects, HT-29 human colon carcinoma cell lines were treated with various concentrations of beta-escin and analyzed by flow cytometry for apoptosis and cell cycle progression. Beta-escin treatment in HT-29 cells induced growth arrest at the G1-S phase, which was associated with the induction of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1), and this correlated with reduced phosphorylation of retinoblastoma protein. Results also indicate that beta-escin inhibited growth of colon cancer cells with either wild-type or mutant p53. This novel feature of beta-escin, a triterpene saponin, may be a useful candidate agent for colon cancer chemoprevention and treatment.

Aesculus↗
PubMed2006

Horse chestnut extract induces contraction force generation in fibroblasts through activation of Rho/Rho kinase.

Contraction forces generated by non-muscle cells such as fibroblasts play important roles in determining cell morphology, vasoconstriction, and/or wound healing. However, few factors that induce cell contraction forces are known, such as lysophosphatidic acid and thrombin. Our study analyzed various plant extracts for ingredients that induce generation of cell contraction forces in fibroblasts populating collagen gels. We found that an extract of Horse chestnut (Aesculus hippocastanum) is able to induce such contraction forces in fibroblasts. The involvement of actin polymerization and stress fiber formation in the force generation was suggested by inhibition of this effect by cytochalasin D and by Rhodamine phalloidin. Rho kinase inhibitors (Y27632 and HA1077) and a Rho inhibitor (exoenzyme C3) significantly inhibited the force generation induced by the Horse chestnut extract. H7, which inhibits Rho kinase as well as other protein kinases, also significantly inhibited induction of force generation. However, inhibitors of other protein kinases such as myosin light chain kinase (ML-9), protein kinase C (Calphostin), protein kinase A (KT5720), and tyrosine kinase (Genistein, Herbimycin A) had no effect on force generation induced by Horse chestnut extract. These results suggest that the Horse chestnut extract induces generation of contraction forces in fibroblasts through stress fiber formation followed by activation of Rho protein and Rho kinase but not myosin light chain kinase or other protein kinases.

Aesculus↗
PubMed2004

[Population structure and distribution pattern of rare plant communities in Houhe Nature Reserve].

An investigation on the size structure and spatial pattern of 26 major tree species with a diameter at breast height (DBH) > or = 5 cm was made on a 1 hm2 fixed plot in the mixed evergreen and deciduous broad-leaved forest in Houhe National Nature Reserve of Central China. The results showed that 7 populations of the 26 species, i.e., Dipteronia sinensi, Aesculus wilsonii, Pterostyrax psilophyllus, Davidia involucrate, Euptelea pleiosperma, Tetracentron sinense and Cercidiphyllum japonicum, were rare endangered, species, and two of the 7 populations, T. sinense and C. japonicum, were very limited in numbers. The population structure of P. psilophyllus was in declining, and that of the rest was in growing. The spatial distribution pattern of P. psilophyllus, A. wilsonii and T. sinense was in random, and that of the others was clumped. Among the other 19 non-rare populations, the population structure of P. wilsonii was in declining, that of D. lotus, A. palmatum, A. wilsonii, A. franchetii, M. cuneifolia and H. dulcis was stable, and the rest was in growing. The spatial distribution pattern of D. lotus and H. dulcis was in random, and that of the others was clumped. On the whole, the growing populations were dominant, amounting to 61.54%, and the stable and declining populations accounted for 6.92% and 11.54%, respectively. The results of the two judging methods were consistent, showing that the distribution pattern of clumping (80.77%) was dominant, while the random and even distribution patterns were infrequent.

Aesculus↗
PubMed2006

Using horsechestnut seed extract in the treatment of venous leg ulcers: a cost-benefit analysis.

Venous leg ulcers affect approximately 0.6% of the western population, consuming millions of healthcare dollars every year. To determine whether an alternative venous ulcer treatment using horsechestnut seed extract-- Aesculus hippocastanum-- and conventional therapy involving dressings and compression was more cost-effective than using conventional therapy alone, a 12-week cost-benefit analysis of horsechestnut seed extract therapy was conducted. The study, using data from a 12-week prospective, randomized, placebo-controlled trial conducted in South Australia in 2002-2004, involved 54 patients with venous ulceration who received treatment through a large South Australian district nursing service. Taking into account the cost of horsechestnut seed extract, dressing materials, travel, staff salaries, and infrastructure for each patient, horsechestnut seed extract therapy combined with conventional therapy was found to be more cost-effective than conventional therapy alone with an average savings of AUD 95 in organizational costs and AUD 10 in dressing materials per patient. This study confirms that dressing change frequency has a significant impact on the total cost of wound care and suggests that district nursing service operation efficiency may be enhanced through the use of horsechestnut seed extract as a result of less frequent nursing visits. Further study of this treatment modality is warranted.

Aesculus↗
PubMedDate not supplied

A horse chestnut extract, which induces contraction forces in fibroblasts, is a potent anti-aging ingredient.

Contraction forces generated by non-muscle cells, such as fibroblasts, play important roles in determining cell morphology, vasoconstriction, and/or wound healing. We have searched among various plant extracts for ingredients that generate cell contraction forces using fibroblast-populated collagen gels. Using that model, we found that an extract of horse chestnuts (Aesculus hippocastanum) is able to generate such contraction forces in fibroblasts. The involvement of stress fiber formation in that response is suggested by the inhibition of such force generation by cytochalasin D and rhodamine phalloidin stain. Clinical testing of the extract was carried out using 40 healthy female volunteers. A gel formulation that included 3% of the extract was applied topically to the skin around the eye three times daily for nine weeks. The efficacy of the extract to diminish wrinkles was evaluated by visual scoring based on photo scales. After six weeks, significant decreases in the wrinkle scores at the corners of the eye or in the lower eyelid skin were observed compared with controls. After nine weeks, similar results were obtained. Taken together, our results suggest that an extract of horse chestnuts can generate contraction forces in fibroblasts and is a potent anti-aging ingredient.

Adult↗