|
|
Silver based raw materials for cosmetic purposes
Čaková, Adriana ; Ďubašáková, Mária (referee) ; Zemanová, Jana (advisor)
The purpose of this bachelor’s thesis was a research about silver based cosmetic products and determination of antimicrobial activity on certain species of microorganisms by chosen silver based cosmetic products. Theoretical part is focused on the problematics of silver based cosmetic products, on their main purpose, physically chemical characteristics and toxicological profile. In the theoretical part is also mentioned problematics of legislative, mainly the safety and real effectivity of tested cosmetic products. Experimental part was focused on determination of antimicrobial activity of chosen silver based cosmetic products. Two silver based cosmetic product were used to determined antimicrobial activity on selected microorganisms Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Kocuria rosea, Serratia marcescens a Candida vini. From result it is apparent, that both of used Cosmetic product showed antimicrobial activity, but not on every used microorganism.
|
|
|
Preparation and application of combined functionalized nanomaterials with antimicrobial effect in food and cosmetics
Vojteková, Vanesa ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The presented diploma thesis is focused on the preparation of combined nanomaterials that were functionalized with an antimicrobial ingredient. Liposomes were prepared without the addition of polyhydroxybutyrate but also with its addition. The nanofibers were obtained from gelatin solution by electrospinning. Thymol, eugenol, curcumin and vitamin E were used for functionalization. In the theoretical part, individual bioactive components, materials for the preparation of nanoparticles and nanofibers as well as methods of synthesis of these materials were characterized. The applications of the prepared nanoparticles as preservatives in the food industry and applications of nanofibers in wound healing and in the cosmetics industry have also been described. In the experimental part, the antioxidant activity of the active substances was determined. Two types of liposomes were prepared and evaluated for size, stability and encapsulation efficiency. Subsequently, the release rate of active substances from the prepared liposomes was monitored. Nanofibers with combinations of substances that were encapsulated in liposomes were prepared by electrospinning. The antimicrobial activity of the active ingredients, nanofibers and nanomaterials was monitored on three strains of microorganisms, namely Micrococcus luteus, Staphylococcus epidermidis and Escherichia coli. The individual substances in pure as well as encapsulated form were combined with each other to observe the possible synergistic effect. The prepared nanoparticles and nanofibers with antimicrobial components were tested for cytotoxicity on human keratinocytes. The nanofibers were also subjected to a scratch test, which simulates the wound healing process.
|
|
|
Determination of antimicrobial and antioxidant activity of selected herbal extracts
Čaková, Adriana ; Němcová, Andrea (referee) ; Vítová, Eva (advisor)
Tetradenia spp. is herb naturally growing in Africa and is part of family called Lamiaceae. The herb is used in traditional medicine to cure malaria, angina or as treatment for tropical skin diseases. Maceration was chosen from number of extraction methods, to obtain bioactive compounds from this plant. Optimization was performed with aim to retrieve as much of bioactive compounds as possible. Optimal conditions chosen were: temperature 60 °C, extraction time 40 minutes, solvent 40% ethanol and solid-solvent ratio 1:5. In total 63 aromatic active compounds were found in optimal extract. Terpenes were the most abundant (88,60 %), from them oxygenated monoterpenes (55,65 %) and monoterpenes (29,52 %). Compounds with highest percentage quantity were camphor (51,76 %), cis--ocimene (8,17 %), 3-octyl acetate (7,71 %), trans--ocimene (6,76 %), -terpinene (4,93 %), o-cymene (3,81 %), terpinolene (1,33 %), limonene (1,33 %), camphene (1,19 %) and borneol (1,20 %). Further, total phenolic content was 0,31 ± 0,02 mgGAEml-1, which equals 1,52 ± 0,11 mgGAEg-1 of plant. Antioxidant activity was 417,56 ± 32,84 gTEACml-1 and percentage of radical scavenging activity ABTS•+ was 88,99 ± 7,00 %. Finally antimicrobial activity was determined against bacteria Bacillus cereus, Escherichia coli and yeast Candida glabrata. Against E. coli and C. glabrata there was no inhibition exhibited. Against B. cereus there was seen mild inhibition activity. The results confirm that Tetradenia spp. contain a number of interesting aroma active compounds, which shows antioxidant and antimicrobial activity. The herb has a good potential as natural source of nutritious and sensory active compounds to be used into various foods.
|
|
|
Rosehip – the source of natural compounds
Motúzová, Eliška ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
The goal of this bachelor thesis was to study the antimicrobial activity of various extracts of rosehip tea. As well as to determinate concentration of biologically active compounds, polyfenols and flavonoids, and antioxidant activity in these teas. Teoretical part describes basic information about Rosa canina, general classification of tea, summary of biologically active compounds and basic methods of extraction. Practical part is focused on determination of anioxidant acivity, comcentration of polyfenols and flavonoids in tea extracts and detection of animicrobial activity of these extracts against bacterial strains Serratia marcescens and Micrococcus luteus. The results of this theasis show that aqueous extracts of rosehips tea are animicrobialy active. It was also found, that these extracts have hight contents of polyphenols and flavonoids.
|
|
|
Antimicrobial activity of rosehip teas
Ďubašáková, Mária ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor theses was to determine the concentration of biologically active substances such as polyphenols and flavonoids and also total antioxidant activity of tea extract of rosehip and also research antimicrobial activity and the effective concentration of the extracts against selected bacteria. Theoretical part is focuses on the description of natural antioxidants and active effect against free radicals, description and distribution of tea, botanical and chemical description od rosehip and basic information about bacteria. There is section describe selected methods for the determination of polyphenols, flavonoids, total antioxidant activity of these extracts, and verification of antimicrobial activity against grampositive and gramnegative bacteria in experimental section. From the results is flow, that the analyzed extracts have no inhibition activity against bacteria. Also was found that aqueous extracts has high proportion flavonoids and polyphenols.
|
|
|
Characterization of the genus Plectrantus for use in the food industry
Chmelová, Nikola ; Diviš, Pavel (referee) ; Vítová, Eva (advisor)
The aim of this diploma thesis was to determine the optimal extraction conditions for obtaining an extract from the plant Plectranthus amboinicus. Plectranthus amboinicus is an aromatic herb of the Lamiaceae family containing a large number of bioactive compounds. Because of this, it has a number of biological effects – antimicrobial, anti-inflammatory, antioxidant, analgesic, etc. To maintain the maximum of sensory and nutritionally valuable components of P. amboinicus, a simple maceration of fresh chopped herb was chosen. Maceration was performed under the following conditions: 40 minutes at 40 ° C, solvent 40% ethanol, weight 20 g of herb per 100 ml of solvent. The extract prepared under these optimal conditions was comprehensively characterized in terms of the content of total polyphenols, their concentration was determined to 0,08 ± 0,02 mgGEA·ml-1, which corresponds to 0,40 ± 0,07 mgGEA·g-1 of the plant. The antioxidant activity of the extract was 241,24 ± 29,24 µgTEAC·ml-1 and the radical scavenging activity of ABTS•+ was determined to be 49,29 ± 5,97 %. The antimicrobial activity was verified by the agar well diffusion method. Two types of bacteria were selected for the determination – gram-positive Bacillus cereus, gram-negative Escherichia coli and yeast Candida glabrata. The results showed that the extracts have the highest antimicrobial activity against B. cereus. There were 64 volatile aromatic compounds identified in the extract, with monoterpenes and sesquiterpenes dominating. The obtained results confirm that P. amboinicus, or its prepared extract, has a good potential for use as a new and non-traditional flavor in various foods and delicacies, which can also increase their nutritional value.
|
|
|
Use and application of natural antimicrobial substances
Dzurická, Lucia ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis is focused on the study of antimicrobial activity of plant substances in combination with bacteriocins and the possibility of creating new encapsulated form of supplement which could be used in food and cosmetic products. 5 plant materials were selected: acerola, cinnamon, cloves, orange peel and yacon syrup. Nisin was chosen as the most suitable bacteriocin. In the theoretical part the components with antimicrobial and antioxidant activity are described, such as the materials of plants and animal origin used in this work. Also the possibility of increasing the antimicrobial effect and possible use of natural antimicrobial substances were described. In experimental part, the aqueous extracts of selected plant materials were firstly spectrophotometrically characterized for the content of total polyphenols, flavonoids and antioxidants. Selected substances were encapsulated into liposomes and subsequently preparation of liposomes coated with chitosan was optimized. The particles were tested for size, short and long term stability, encapsulation efficiency and antioxidant activity. Furthermore, the antimicrobial activities of selected components in nonencapsulated and encapsulated form were observed against four strains of microorganisms (Escherichia coli, Micrococcus luteus, Serratia marcescens and Candida glabrata). Also the expected synergisms of the antimicrobial effects of extracts in combination with nisin and prepared particles were observed.
|
|
|
Analysis of active substances contained in lavender and thyme extracts
Vašíčková, Milada ; Vysoká, Marie (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis is focued on active substances contained in lavandula officinalis and common thyme extracts, mainly their possible antimicrobial and antioxidant effects. The theoretical part desrcibes chosen plants, compounds with antimicrobial and antioxidant effects, methods how to obtain and identify said compounds. In the experimental part, aquenous, ethanolic and oil extracts were prepared. Mentioned extracts were spectrophotometrically characterised for total content of polyphenols, total content of flavonoids and antioxidant activity. In conclusion possible applications of extracts in food industry instead of synthetic preservatives and their fotification were discussed.
|
|
|
TiO2 nanoporous surfaces and their properties
Roček, Vojtěch ; Urbánková, Kateřina (referee) ; Drbohlavová, Jana (advisor)
This thesis is focused on creation nanostructured surfaces of titanium dioxide and the use of photocatalytic activity of these surfaces for antimicrobial applications. The work is divided into nine main chapters, in which the literature search for producing these surfaces, the principle of photocatalysis and their typical specifics was made. These theoretical findings are then used to form such layers, analyzing their chemical and physical properties and practical verification of their antimicrobial activity. This work experimentally verified processes to ensure the increase of antimicrobial activity. The results and findings are discussed in the conclusion.
|
|
|
Study of natural antimicrobial mixtures and their stabilization
Vejrostová, Petra ; Veselá, Mária (referee) ; Márová, Ivana (advisor)
Present diploma thesis is focused on natural antimicrobial substances. The aim of the experimental part of thesis was testing of antimicrobial activity of selected natural substances in free and encapsulated forms, preparation of particles and monitoring of their long-term stability. Various teas extracts (aqueous, ethanoic and DMSO) and aqueous herbs extracts were used as plant antimicrobial substances. Liposomes and chitosan particles with encapsulated aqueous teas extracts were prepared by ultrasonication. Encapsulation efficiency, size, stability and antioxidant activity for all particles were specified. Consequently, within a two months period, long-term stability for these particles was monitored. Spectrophotometric method for determining total polyphenols was used for evaluating encapsulation efficiency as well as for monitoring of long-term stability. The DLS method was used for determination of size and stability of particles. Antioxidation activity was monitored by using spectrophotometric method using ABTS. For testing antimicrobial activity of various types of teas, herbs extracts and their mixtures and combianitons with lysozyme and antibiotics, broth dilution methods were used while using both Gram positive and Gram negative bacterial test strains. Antimicrobial activity of prepared particles was also monitored, the antimicrobial activity was especially significant with the chitosan particles. Suitable combinations of natural substances whatever with antimicrobial or antioxidation effect either in free or encapsulated form could be used for applications for example in cosmetics industry, food processing or in medicine.
|
guest ::
