ABSTRACT
Achyrocline satureioides is a South American herb used in traditional medicine to treat a wide range of ailments. The healing and antimicrobial effects of this plant have already been covered by many studies, which have confirmed its beneficial effects on human health. In this study, the antimicrobial effect of A. satureioides hydroalcoholic extract against Escherichia coli ATCC10536, Staphylococcus aureus ATCC25923, Staphylococcus epidermidis ATCC12228 and Lactobacillus acidophilus INCQS00076 was determined. The cytotoxicity of the extract was tested on human HaCaT keratinocytes showing very favourable effects on the proliferation and renewal of keratinocytes. According to the results of the HPLC and GC-MS analyses, the lyophilized extract contained only a minimal amount of fragrance allergens. The extract was then used in two cosmetic formulations, and one of them showed a significant synergistic interaction with other cosmetic components. We suggest the use of A.satureioides hydroalcoholic extract as a suitable antimicrobial component of natural origin for cosmetic preparations as a substitute for commonly used preservatives that can cause skin irritation and as a material with its own biological activity.
ABSTRACT
The aim of this study was to evaluate the influence of model (alcohol, sugar, salt, protein and acid) and real foods and beverages on the viability of probiotics during incubation and artificial digestion. Viability of monocultures Lactobacillus acidophilus CCM4833 and Bifidobacterium breve CCM7825T, and a commercial mixture of 9 probiotic bacterial strains, was tested by cultivation assay and flow cytometry. In model foods, the best viability was determined in the presence of 0.2 g/L glucose, 10% albumin and 10% ethanol. As the most suitable real food for probiotic survival, complex protein and carbohydrate substrates were found, such as beef broth, potato salad with pork, chicken with rice, chocolate spread, porridge and yoghurt. The best liquid was milk and meat broth, followed by Coca-Cola, beer and coffee. Viability of probiotics was higher when consumed with meals than with beverages only. Addition of prebiotics increased the viability of probiotics, especially in presence of instant and fast foods. Generally, the highest viability of probiotics during artificial digestion was observed in mixed culture in the presence of protein, sugar and fat, or their combination. The increase of cell viability observed in such foods during model digestion may further contribute to the positive effect of probiotics on human health.
ABSTRACT
In this study preparation and characterization of new UV-protecting systems based on liposomes/polyhydroxybutyrate (PHB) with encapsulated coffee extracts are presented. Green and roasted coffee extracts with high phenolics content, high antioxidant activity and sun protection factor (SPF) value 40-50 were used as model organic UV filters and encapsulated into liposomes and PHB-liposomes. Particle size and colloid stability was observed by dynamic light scattering and zeta-potential. Toxicity of particles was tested by MTT and LDH assay on HaCaT cell line. All prepared samples showed moderate or high encapsulation efficiency. Addition of PHB up to 50 % of lecithin led to increased size and stability. As optimal addition of 20 % PHB into liposome particles was found leading to optimum size and processing of particles, to high UV-protective effect as well as to increased colloid stability and SPF value during long-term storage. Significant differences in cell viability were found in cytotoxicity studies after exposure of keratinocytes to liposomes with different PHB content. Newly fabricated PHB-liposome particles with coffee extract were not found as toxic for HaCaT cells and in LDH test up to 12 %. These particles can act as active carriers for organic sunscreen components in combination with UV-protective effect of PHB.
