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The aqueous-ethanol extracts (30% ethanol) from Centella asiatica have a stronger antibiotic activity compared to other extracts. In comparison to tetracycline, the antibiotic activity of above extracts can be determined as a poor. The aqueous-ethanol extracts (60% ethanol) showed a stronger antioxidative activity compared to other extracts. In comparison to chlorogenic acid the antioxidative activity of above extracts is poor. There was found no difference in antibiotic and antioxidative activity between extracts obtained from hydroponic and field cultivation. On the other hand, it was found that aqueous-ethanol extract from the herb of Centella asiatica shows the bacteriostatic activity to all Gram-positive and Gram-negative bacteria isolated from wounds of different etiology (MIC, 10–40 mg/ml). This extract did not show any irritative and mutagenic activity according to OECD directives. The mentioned extract applied topically in form of 1% cream showed tendency to reduce oedema induced by carrageen after 3 h from application (ca. 12%). We conclude that the topically applied preparation (cream or gel) containing 5% of investigated aqueous extract from herb of Centella asiatica (50 mg/g of preparation) can be used for healing of infected wounds in hospitalized patients.
The aim of the work was to find how the abiotic stress factors, such as Zn and Ti ions, influenced on growth factor and accumulation of some elements in plantlets of C. asiatica (L.) Urban Apiaceae). Plantlets were cultured on Nitsch and Nitsch (NN) or Schenk and Hildebrandt (SH) modified media with various growth regulators. Zn ions as ZnSO₄ were additionaly put into medium in 4 concentrations for 3 to 7 weeks. Ti ions as 0.04% solution of Tytanit - foliar fertilizer were added into medium or stems of plantlets were soaking in solution only or with subsequent rinsing in sterile water. The concentrations of selected bioelements: Cu, Mn, Zn, Fe, Ca and Mg (determined by ASA using Spectrophotometer SP 1900 Pye Unicam in “free” (soluble in water) and “bound” (in cell structure) forms were evaluated The observations have shown that Zn and Ti application influenced on the weight and development of Centella asiatica cultured in vitro and caused changes in their mineral composition. Important differences in concentration of evaluated elements were found in studied samples. The content of analysed bioelements was dependent not only on Zn concentration in the medium but also of the form of Ti application or of the duration of the experiment.
Solid Phase Microextraction (SPME) is used as a quick and easy alternative to standard distillation in essential oils composition assays. Due to the absence of the distillation step a considerable reduction of sample volume and of the time of sample preparation is possible. This method was used in experiments with essential oils obtained from Crithmum maritimum L. and Centella asiatica Urban (= Hydrocotyle asiatica L.). In this work the overground parts of Crithmum maritimum were analysed. The material was collected in 2003 from places of natural occurrence in Greece and Croatia, from a garden cultivation in Gdańsk, during the whole vegetation period, from plants from a control group and plants fertilised with Tytanit formula. Centella asiatica material was collected directly from an in vitro culture and from plants cultivated for six months in flowerpots, where they were transferred after five passages of in vitro culture. The analysis of components of monoterpene fraction was performed by gas chromatography. The percentage and composition of essential oils were different in all the tested samples. Crithmum maritimum material (from places of natural occurrence and from garden cultivation) shows the biggest differences in the content of a-pinene, 7-terpinene and sabinene. Plants treated with a Tytanit solution responded by increase of total percentage of essential oil with higher contents of 7-terpinene and sabinene. In Centella asiatica a higher percentage of essential oil (mainly a-pinene) was observed in roots than in leaves. Leaves treated with Ti ions had a higher amount of a-pinene than the control ones. Solid Phase Microextraction (SPME) method enables fast estimation of interference of each tested factor on the biosynthesis and composition of the essential oil. SPME was also useful in selection of the proper material for next experiments.
Antifungal activity of water soluble exudates of pea leaves was assayed. Exudates of different nodal leaves were collected by dipping them in sterilized distilled water for different length of time and conidial germination of four non-pathogenic to pea fungi (Alternaria solani, Curvularia lunata, Helminthosporium penniseti and H. echinocloa) and one pea pathogenic to pea fungus (Erysiphe pisi) was observed in the collected exudates. The leaf exudates inhibited differently conidial germination and A. solani and C. lunata were found highly susceptible. Conidial germination on exudate-depleted pea leaves showed better germination of E. pisi than on non-depleted leaves. Bipolar germination was the highest on II and III nodal leaves dipped in distilled water for 18 h while after 24 h it was the highest on I nodal leaves following dipping in distilled water. Similarly, conidial germination of E. pisi was observed on different nodal leaves of pea of different age. It was very clear that young leaves did not support germination at all and on the same nodal leaves conidia germinated after the leaves became older. No germination was observed on less than 20-day-old leaves. Moreover, 30-day-old leaves were found to be highly susceptible as bipolar germination of E. pisi conidia was maximum on such leaves and did not increase with aging.
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