National Repository of Grey Literature 16 records found  1 - 10next  jump to record: Search took 0.02 seconds. 
Isolation of active compounds from algae and their application in cosmetic products
Nováková, Laura ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The bachelor thesis is dedicated to the study of active substances and antioxidant effects of cultivated microalgae. We compared the results with a commercial alga that is freely available. In the theoretical part we focused on description of algal metabolites in cosmetics and a brief description of the methods used in their testing. In the experimental part there were analyzed three types of extracts (aqueous, alcohol and oil) from 4 species of algae. It is mainly the content of polyphenols, flavonoids and antioxidant activity that is determined. According to the results, the highest content of active substances was found in oil extracts. All extracts were encapsulated into liposomes. The average size of the nanoparticles was in range of 200 nm to 300 nm. The particles were stable enough also for long-term stability. The largest decrease was observed in the oil extract of the cultivated algae Chlorella vulgaris. The cytotoxicity of oil extracts was realized by MTT test on human cell cultures HaCaT. Finally, we concluded that the prepared liposomal particles could be used for anti-aging cosmetics.
Use of algae extracts in cosmetics
Plášková, Anna ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
This thesis is focused on a preparation of extracts from selected species of algal and cyanobacterial strains, their characterization, a cytotoxicity testing and a use in cosmetic products. The theoretical part contains the review of a taxonomic classification and parameters of algae and cyanobacteria and basic information about used organisms. There is a description of the most significant factors influencing the algae cultivation and production of biomass. Further, active substances of algae and cyanobacteria, which could be used in cosmetic products as UV protective substances, were described. An overview of extraction techniques, encapsulation of active substance into liposomes and particles characterization, antioxidant activity analysis, and cytotoxicity tests is given too. In experimental part, antioxidant activity of algal extracts and chlorophyll a and carotenoid content were determined spectrophotometrically. The long-term stability of extracts was monitored for three weeks. Liposomes were prepared by sonification and encapsulation activity was analysed. The Dynamic Light Scattering method (DLS) was used for analysis of polydispersity and size of liposomes. Colloid stability of particles was determined by zeta potential. Cytotoxicity tests were performed using MTT assay. The prepared extracts, particles and lyophilized biomass of algal and cyanobacterial strain were further used as active substances in the formulation of cosmetic products (type o/w). These creams were tested on human skin.
Amount of selected biologically active compounds in Stevia rebaudiana
Porubčanová, Vladimíra ; Jurečková, Zuzana (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with plant, called stevia rebaudiana and analysis of phenolic compounds in the extracts from it. The theoretical part describes its botanical characteristics, chemical constitution and effect on humans health. This thesis is interested in sweetener, produced from stevia, comercionally used as E 960: steviol-glykosides, too. There is listed register of companies producing this sweetener and food products, where stevia is used in. The experimental part of thesis is focused to analysis of total phenolic content in stevia extracts, because leaves of stevia are primary used for sweetening of tea. The main aim of the thesis was find out, how is total phenolic content changed during extraction of leaves in time, in water with different temperature and in different samples.
Isolation and characterization of natural antimycotics and their potential applications
Dvořáková, Eva ; Hoová, Julie (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis was focused on preparation and characterization of products containing natural antimycotic ingredients. The theoretical part summarizes the current issue of increased presence of mycoses and yeast diseases in connection with the extension of the problem of reduced immunity. Furthermore, the problem of synthetic drugs and antimycotics compared to alternatives of natural origin was described. In the experimental part, selected extracts (aqueous, ethanolic and lipidic) were prepared, characterized and subsequently encapsulated into liposomes. The content of polyphenols, flavonoids and the total antioxidant activity of extracts was measured. In liposomes, the encapsulation efficiency, size, stability and long-term stability were measured. In addition, the antimycotic activity of individual extracts and liposomes against Candida glabrata was studied. For comparison, the antifungal activity of the commercial drug clotrimazole was also tested. Lipidic extracts showed highest antimycotic activity from all of the prepared extracts, which is why these extracts were used to prepare antifungal gels and suppositories. More specifically, lipidic extracts of nasturcium, cinnamon, ginger and liposomes containing them were used. Their antimycotic activity was also tested and confirmed for these preparations. Finally, the cytotoxicity test on the HaCaT human cell line showed that used extracts and liposome particles are safe and that the prepared products could thus serve as an alternative to synthetically prepared antimycotics in the future.
Preparation of organic fibers with the addition of algae extracts
Tuhrinská, Terézia ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
The presented bachelor thesis is focused on the preparation and characterization of organic fibers with an admixture of pre-prepared extracts of microalgae and cyanobacteria containing valuable active compounds. The theoretical part describes selected metabolites of microalgae and cyanobacteria, methods of their analysis, the issue of encapsulation and incorporation of active substances into nanofibers and presents some methods of their preparation. In the experimental part of this thesis, selected strains from the CCALA collection were first cultured. Subsequently, aqueous, ethanol and hexane extracts of biomass from cultured and commercial microalgae and cyanobacteria were prepared. The prepared extracts were spectrophotometrically evaluated in terms of the concentration of chlorophylls, carotenoids, antioxidants, polyphenols, and total proteins present. In addition, 96 % ethanol extracts were subjected to more accurate analysis of chlorophylls and carotenoids by HPLC. The highest antioxidant activity was observed for aqueous extracts. Gelatin nanofibers containing selected extracts were formed by electrospinning method. The formed fibers were examined afterwards to identify a mass fraction of incorporated microalgal and cyanobacterial substances. The fibers were further tested for antioxidant activity with the TEAC assay. The most pronounced antioxidant effect was detected for the fiber with incorporated aqueous extract of the cyanobacterium Arthrospira maxima. Finally, the fibers were tested for their safety in contact with human cells. The amount of fibers used did not show any cytotoxic effect on human keratinocytes and the tested materials can thus be considered safe for application in cosmetics.
Plant-based cosmetic products
Horváthová, Iveta ; Pavelková, Renata (referee) ; Skoumalová, Petra (advisor)
The aim of this bachelor thesis was studying an antimicrobial activity of selected herbal extracts and their encapsulated forms as liposomes. Furthemore, the thesis focuses on determonation of biologically active compounds, natural pigments and antioxidant activity. 6 kinds of herbs were studied - Humulus lupulus, Matricaria chamomilla, Taraxum officinale, Bellis Perennis, Cymbopogon citratus and Rubus Fruticosus. In teoretical part, the general characteristics of herbs and their use are described, it also includes the description of active compounds, microorganisms and used methods. Practical part is focused on characterisation of herbs from the perspective of antioxidant activity, determination of totaly phenolic content and flavonoids, chlorophyll and carotenoids. For analysis of antioxidant activity, concentration of phenolic compounds and flavonoids and antimicrobial activity aqueous and 20% ethanol extracts were prepared. Based on the obtained results, selected extracts were encapsulated into various types of liposomes consisting egg yolk, soy or sunflower lecithin. Generally, ethanol extracts showed higher content of active compounds. For chlorophyll and total carotenoid content determination the highest content of natural pigments was found in Taraxum officinale. Furthemore, antimicrobial activity of extracts and liposomes against 6 strains were determined - Micrococcus luteus, Serratia marcescens, Escherichia coli, Propionibacterium acnes, Staphylococcus epidermidis and Candida glabrata. The highest inhibitory effect was found in Matricaria chamomilla and Cymbopogon citratus samples. Encapsulation effectivity, size, stability and long-term stability of liposomes after a week and two months were determined. From the perspective of zeta potential all the particles were stable and reached a good encapsulation effectivity. It turned out that after two monts of storage the particles decomposed and active compounds into surroundings were released. Selected herbs generally had high content of antioxidants and active compouds. The most suitable lecithin for encapsulation was shown to be sunflower lecithin.
Alleopathic potential of plants of hemp (\kur{Cannabis sativa})
KLEJNA, Tomáš
The aim of the work was to compare the effects of germinating seeds, fresh flowers and aqueous extracts from fresh and dried parts (leaves and flowers) of hemp plants on seed germination of model crops - wheat, oats, white mustard, narrow-leaved lupin, white clover and lettuce in laboratory conditions. After 3 days of germination, the total length of the roots and shoots was measured. In individual variants, the relative allelopathic effect, average germination and statistical significance were evaluated. The effect of the distance of germinating seeds from samples of hemp material was also monitored. The effect of germinating hemp seeds, with the exception of oats, has not proved to be very significant. The effect of parts and aqueous extracts of hemp plants was as follows: -statistically significant inhibitory effect of the aqueous extract of the dried flower on the germination of wheat -statistically significant inhibitory effect of fresh flowers and extract from dried leaves of flowering plants on the germination of oats, there is also a statistically significant effect of the distance of germinating seeds from the sample of hemp material -statistically significant inhibitory effect of fresh flowers and extracts of fresh and dried leaves on the germination of white mustard, there is also an effect on average germination values -practically no or stimulating effect on the germination of legumes: narrow-leaved lupins and white clover -statistically significant inhibitory effect of fresh flowers and fresh leaf extract on lettuce germination, again with an effect on average germination
USE OF COMPLEX EXTRACTS FROM PLANT AND MICROORGANISMS IN FOODS AND COSMETICS
Uhlířová, Renata ; Kovalčík, Adriána (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on optimalization of preparation of extracts of various origin (plant and microbial). The influence of extraction agent, disintegration of microbial cells as well as special techniques for enhancement of extraction process effectiveness (ultrasound and microwaves) were monitored. As part of the characterization, considering the source material, the composition of the prepared extracts was analyzed both spectrophotometrically and using liquid and gas chromatography. The most suitable extraction procedure varies depending on the type of material. For herbal samples, the highest content of active substances was achieved when the extraction facilitated by microwaves was used. Contrarily, the optimal method for cyanobacteria is the traditional extraction method, which is carried out for 24 hours at laboratory temperature. The most suitable method for extracting the active substances from yeast was a combination of DMSO, ethanol and hexane. Further, the effect of extracts on microbial cultures of bacteria (E. coli, S. epidermidis, C. acnes) and yeast (C. glabrata) was observed. For cytotoxicity evaluation MTT and LDH assays were performed on HaCaT and Caco2 human cell lines. The antimicrobial tests have demonstrated the antimicrobial, antibacterial and antifungal effect of a numerous extracts, especially the essential oils of Lavandula angustifolia and Mentha piperita. On the other hand, the cytotoxicity tests showed that the most of the extracts were safe for the use in the food industry and cosmetics within a range of up to 10% by volume. To improve stability, the prepared extracts were enclosed into liposomal particles enriched with PHB polymer (0–100%). Using a ZeteSizer NanoZS device, the particles' size, polydispersity index, and colloidal stability were assessed. The cryoTEM was used to examine the particle´s morphology. Liposomes and liposomes with the addition of 20 % PHB (PHB20) were evaluated as the most suitable particles for encapsulation of the prepared extracts. Excellent stability and high encapsulation efficiency were displayed by the produced particles. Genotoxicity testing with SOS chromotest on the model organism E. coli did not reveal any genotoxic effects. As an alternative method to achieve stabilization of active substances, nanofibers from PHB were prepared by three different techniques and gelatin nanofibers by electrospinning. The fibers were monitored for their diameter, uniformity, distribution on the collector using SEM and the gradual release of active substances from the fiber structure. The evaluations revealed that the forcespinning and electrospinning techniques were the most appropriate for further investigation. A continuous release of active ingredients was achieved by incorporating extracts into nanofibers. Several applications of prepared materials in the food industry and cosmetics were designed and developed as part of this work. The base emulsion's stability and general qualities were improved when green coffee and carotenogenic yeast extracts were added. The usage of emulsions containing coffee and yeast extracts would be suitable as sunscreens, and after the addition of Spirulina extract, as day or night anti-wrinkle creams. Energy drinks of the new type based on coffee with the addition of encapsulated plant extracts enable gradual release of caffeine and antioxidants during digestion.
Preparation of organic fibers with the addition of algae extracts
Tuhrinská, Terézia ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
The presented bachelor thesis is focused on the preparation and characterization of organic fibers with an admixture of pre-prepared extracts of microalgae and cyanobacteria containing valuable active compounds. The theoretical part describes selected metabolites of microalgae and cyanobacteria, methods of their analysis, the issue of encapsulation and incorporation of active substances into nanofibers and presents some methods of their preparation. In the experimental part of this thesis, selected strains from the CCALA collection were first cultured. Subsequently, aqueous, ethanol and hexane extracts of biomass from cultured and commercial microalgae and cyanobacteria were prepared. The prepared extracts were spectrophotometrically evaluated in terms of the concentration of chlorophylls, carotenoids, antioxidants, polyphenols, and total proteins present. In addition, 96 % ethanol extracts were subjected to more accurate analysis of chlorophylls and carotenoids by HPLC. The highest antioxidant activity was observed for aqueous extracts. Gelatin nanofibers containing selected extracts were formed by electrospinning method. The formed fibers were examined afterwards to identify a mass fraction of incorporated microalgal and cyanobacterial substances. The fibers were further tested for antioxidant activity with the TEAC assay. The most pronounced antioxidant effect was detected for the fiber with incorporated aqueous extract of the cyanobacterium Arthrospira maxima. Finally, the fibers were tested for their safety in contact with human cells. The amount of fibers used did not show any cytotoxic effect on human keratinocytes and the tested materials can thus be considered safe for application in cosmetics.
Plant-based cosmetic products
Horváthová, Iveta ; Pavelková, Renata (referee) ; Skoumalová, Petra (advisor)
The aim of this bachelor thesis was studying an antimicrobial activity of selected herbal extracts and their encapsulated forms as liposomes. Furthemore, the thesis focuses on determonation of biologically active compounds, natural pigments and antioxidant activity. 6 kinds of herbs were studied - Humulus lupulus, Matricaria chamomilla, Taraxum officinale, Bellis Perennis, Cymbopogon citratus and Rubus Fruticosus. In teoretical part, the general characteristics of herbs and their use are described, it also includes the description of active compounds, microorganisms and used methods. Practical part is focused on characterisation of herbs from the perspective of antioxidant activity, determination of totaly phenolic content and flavonoids, chlorophyll and carotenoids. For analysis of antioxidant activity, concentration of phenolic compounds and flavonoids and antimicrobial activity aqueous and 20% ethanol extracts were prepared. Based on the obtained results, selected extracts were encapsulated into various types of liposomes consisting egg yolk, soy or sunflower lecithin. Generally, ethanol extracts showed higher content of active compounds. For chlorophyll and total carotenoid content determination the highest content of natural pigments was found in Taraxum officinale. Furthemore, antimicrobial activity of extracts and liposomes against 6 strains were determined - Micrococcus luteus, Serratia marcescens, Escherichia coli, Propionibacterium acnes, Staphylococcus epidermidis and Candida glabrata. The highest inhibitory effect was found in Matricaria chamomilla and Cymbopogon citratus samples. Encapsulation effectivity, size, stability and long-term stability of liposomes after a week and two months were determined. From the perspective of zeta potential all the particles were stable and reached a good encapsulation effectivity. It turned out that after two monts of storage the particles decomposed and active compounds into surroundings were released. Selected herbs generally had high content of antioxidants and active compouds. The most suitable lecithin for encapsulation was shown to be sunflower lecithin.

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