National Repository of Grey Literature 14 records found  previous11 - 14  jump to record: Search took 0.01 seconds. 
Use of cell cultures to test cytotoxicity of natural substances
Blažková, Veronika ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This thesis is aimed on study of cell cultures, primarily on introduction of techniques for cultivation of human cells and optimization of their usage in cytotoxicity tests. The thesis is aimed preferably on natural substances and liposomes that are suitable to be used in cosmetics. Theoretical part contains literature review focused on overview of cell cultures, appropriate cultivation conditions for in vitro testing and summary of cytotoxicity tests. Experimental part contains characteristics of natural extracts with antimicrobial effect in terms of content of polyphenols, flavonoids and antioxidant activity. Further, these extracts were encapsulated into the liposomes. Encapsulation effectivity was determined. Distribution of particles size by dynamic light scattering and finally also stability of prepared particles were also determined. Long-term stability in water and gel environment was tested too. This thesis also contains study of optimization of cell culture of human skin keratinocytes cultivation and use of those cells for testing cytotoxicity of selected natural substances by MTT method.
Study of rose hip bioactive compounds
Konderla, Patrik ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
Purpose of this thesis was research the content of biologically active substances in herbal rosehip extracts and also determination of antimicrobial and antioxidant activity of these extracts. Teoretical part describes informations about Rosa canina L., detailed specification of biologically active substances, specification of antioxidation and overview of methods determine antioxidant compound and antimicrobial activity. In the practical part was by combination of different solvents, procedures and herbal materials, made 21 extracts of Rosa canina L.. From measuring of these extracts, was made extraction curves and also was determined antimicrobial efficiency against bacterial strains Serratia marcescesns, Bacillus subtilis, Bacillus cereus and Micrococcus luteus. Results shows, that also all extracts has some antimicrobial activity, but only against microorganisms Micrococcus luteus and Bacillus cereus. Also was found that bud extracts contains more bioactive compounds soluble in ethanol, meanwhile rose hip extracts contains more bioactive compounds soluble in water.
Preparation of some application formula of antimicrobial substances
Krempaský, Kamil ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The main aim of this study is to determine antimicrobial activity of herbal extracts and also encapsulate these extracts and lysozyme to liposomes. The extracts were prepared from above ground part of wormwood (Artemisia absinthium), aerial part of breckland thyme (Thymus serpyllum), the root of purple coneflower (Echinacea purpurea), liquorice (Glycyrrhiza glabra), corolla of pot marigold (Calendula officinalis) and berries of sea buckthorn (Hippophae rhamnoides). In all extracts antioxidant activity and the amount of total polyphenols and flavonoids was determined. All of these extracts and also lysozyme were used for encapsulation to liposomes. Prepared liposomes were then tested for their stability. Further, encapsulated as well as free extracts were tested for their antimicrobial activity on Escherichia coli, Serratia marcescens, Micrococcus luteus and Bacillus subtilis. Extract from Echinacea purpurea showed the highest antimicrobial activity.
Preparation and testing of application forms for natural antimicrobial substances
Vajglová, Klára ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
The goal of this bachelor thesis was the study of antimicrobial and antioxidant effects of some herbal extracts: cloves, nettle, sage, chamomile, rosemary, elderberry, lavender and also lysozyme. Further, herbal extracts effect on Gram positive and Gram negative bacteria were compared. In the theoretical part were briefly characterized lysozyme, polyphenols, flavonoids and selected strains of microorganisms. In the experimental section characterization of herbs with antimicrobial and antioxidant effect was proved. Particles containing herbal extracts were prepared and encapsulation efficiency was determined. In some of tested herbs encapsulation efficiency of up to 80% was reached. Stability of the prepared liposomes was tested in the model digestive conditions and after 1 week and 1 month incubation period in model foods. Antimicrobial activity was tested on selected representatives of Gram negative and Gram positive bacteria. Gram positive bacteria were more sensitive to herbal extracts and liposomes containing encapsulated herbs, while lysozyme exhibited higher effect to Gram negative bacteria. Prepared particles with encapsulated antimicrobial extracts are especially suitable for use in the food industry.

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