http://repositorio.ufc.br/handle/riufc/15283 Fri, 19 Jun 2026 15:29:05 GMT 2026-06-19T15:29:05Z http://repositorio.ufc.br/handle/riufc/86259 Título: Avaliação dos efeitos do óleo essencial de lippia sidoides na criopreservação de folículos pré-antrais inclusos em córtex ovariano bovino Autor(es): Chaves, Sueline Cavalcante Abstract: Cryopreservation of ovarian tissue is an important strategy for preserving fertility in mammals; however, its efficiency can be compromised by structural, cellular, and biochemical damage resulting from oxidative stress generated during the freezing and thawing processes. In this context, the present study aimed to evaluate the effects of different concentrations of Lippia sidoides essential oil on the viability of bovine cumulus cells, as well as during the vitrification of bovine ovarian tissue. Bovine cumulus cells were cultured in vitro with different concentrations of Lippia sidoides essential oil (4, 40, and 400 µg/mL), and cell viability was evaluated using the calcein-AM and ethidium homodimer-1 fluorescence assay. Bovine ovaries were collected at a local slaughterhouse, and fragments of the ovarian cortex were subjected to vitrification in the absence (vitrified control) or in the presence of L. sidoides essential oil at concentrations of 4, 40, and 400 µg/mL. After warming, the fragments were cultured in vitro for 24 hours at 38.5°C with 5% CO₂. Subsequently, ovarian tissue cell viability, morphological integrity and follicular activation, stromal cell density, extracellular matrix collagen content, and oxidative profile were evaluated through the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and reduced thiol levels. The results demonstrated that the effects of L. sidoides essential oil were concentration-dependent. Concentrations of 4 and 40 µg/mL, especially 40 µg/mL, favoured the preservation of cumulus cell and ovarian tissue viability, follicular morphology and activation, ovarian stromal organisation, and redox balance after vitrification and in vitro culture. On the other hand, the concentration of 400 µg/mL did not promote additional benefits and was associated with a lower proportion of morphologically normal follicles and the absence of stimulation of follicular activation when compared to lower concentrations. It is concluded that L. sidoides essential oil, at a concentration of 40 µg/mL, has potential as an adjuvant agent in bovine ovarian tissue vitrification protocols, contributing to the structural and functional preservation of the tissue after warming. Tipo: Dissertação Wed, 25 Feb 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/86259 2026-02-25T00:00:00Z http://repositorio.ufc.br/handle/riufc/85509 Título: Avaliação do efeito do timol durante a vitrificação de folículos pré-antrais inclusos em tecido ovariano bovino Autor(es): Silva, Andreza de Aguiar Abstract: Cryopreservation is a widely used strategy for preserving fertility; however, vitrification still has limitations associated with mechanical, chemical, and oxidative stress, which can compromise tissue integrity after rewarming. In this context, antioxidant supplementation has been proposed as a promising approach to minimize cryoinjuries. The present study aimed to evaluate the dose-response effects and antioxidant potential of thymol during the vitrification of bovine ovarian tissue. Initially, a dose-response assay was conducted on bovine cumulus cells, cultured in vitro and exposed to different concentrations of thymol (2.5, 25, and 250 μg/mL), in order to evaluate cell viability and cytotoxicity using calcein-AM and ethidium homodimer-1 assays. Next, fragments of bovine ovarian cortex were fixed in 10% paraformaldehyde (non-vitrified control) or subjected to vitrification in solutions supplemented with thymol at the same concentrations. After storage in liquid nitrogen, the tissues were rewarmed in solutions with decreasing concentrations of sucrose; part of the samples was analyzed immediately after rewarming, while the rest were incubated in vitro for 24 h. Tissue integrity was assessed by follicular morphology, ovarian stromal density, and extracellular matrix components, including collagen and glycosaminoglycans. The redox state was analyzed by antioxidant enzyme activity (SOD, CAT, and GPX) and thiol and nitrite levels. The results of the cumulus cell assay showed that 25 μg/mL and 250 μg/mL of thymol increased calcein labeling compared to the control medium, which is indicative of cell viability. Vitrification of ovarian tissue promoted changes in the redox state, evidenced by thiol depletion and reduced GPX activity. Supplementation with 25 μg/mL thymol increased SOD activity in vitrified tissue, which may represent a response to oxidative stress. On the other hand, the presence of 250 μg/mL thymol preserved thiol levels and GPX activity similar to those in non-vitrified tissue. Nitrite levels were reduced after vitrification in all groups, likely reflecting metabolic suppression. In addition, thymol, at all concentrations, increased the proportion of morphologically normal follicles, preserved ovarian stromal density, and maintained extracellular matrix components after rewarming. It is concluded that the presence of 250 μg/mL thymol in the vitrification solution of bovine ovarian cortex has cytoprotective effects that contribute to maintaining redox balance after rewarming, and to preserving the structural integrity of the tissue. Tipo: Dissertação Wed, 25 Feb 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85509 2026-02-25T00:00:00Z http://repositorio.ufc.br/handle/riufc/85401 Título: Uso de sucralose e glicosídeo de esteviol reduz açúcar, custo de produção e aceitação de refrigerantes Autor(es): Chaves, Maria Jeane Araújo Abstract: The synergism of sweeteners in soft drinks is an innovation for the food biotechnology sector, acting in sugar reduction and health promotion. This study aimed to develop soft drinks with sweetener blends of sucralose and steviol glycoside, analyze production costs and sensory properties. In a soft drink industry in the city of Sobral/CE, cola, guarana, and orange flavors were tested. The groups included the standard formula and modifications with 50% and 75% sugar reduction and blends with progressive sweetener concentration. The relative values of the ingredients indicated the impact of sweetness on the price, and prospecting on an industrial scale determined the final price and variances from the standard. Organoleptic tests in a crossover model with 80 volunteers for tasting used a 9-point hedonic scale. Regarding production costs, sugar was the main modulator of the value of the soft drinks for cola and guarana, while for orange it was concentrated juice. There was a decrease in the final price with the modifications, with the 75% reduction being more noticeable for guarana and less so for orange. Regarding sensory properties, there was a tendency towards reduced acceptance between "I liked it very much" (score 8) and "I liked it moderately" (score 7) in aroma, flavor, and overall impression when comparing the standard with blends, and especially in color for cola and texture for orange. The partial substitution of sugar by adding blends can generate more economically competitive soft drinks, and the slightly lower acceptance with sweeteners corroborates the literature, validating the quality of the products. Tipo: Dissertação Thu, 15 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85401 2026-01-15T00:00:00Z http://repositorio.ufc.br/handle/riufc/83337 Título: Atividade antifúngica e antibiofilme de k-aureina e seu efeito sobre os fatores de virulência de isolados de Candida albicans Autor(es): Silva, Maria Laína Abstract: Candida albicans is considered one of the most important opportunistic fungal pathogens, due to its large arsenal of virulence factors that help throughout the progress of the infection. Combined with this scenario, the emergence of fungal resistance demonstrated the need for the development of more effective antifungals. Thus, antimicrobial peptides (AMPs) appear as an alternative, among these, aurein has great antimicrobial action, becoming the basis for the discovery of other bioactive molecules, such as K-aurein (K-au). In this perspective, the study aimed to demonstrate the antifungal activity of K-aurein and the impact of subinhibitory concentrations on the virulence profile of C. albicans isolates. For this, tests were performed to determine the antifungal activity recommended by the Clinical & Laboratory Standards Institute (CLSI) and to analyze the kinetics of death of the isolates against K-au. For the study of virulence factors, the evaluation of the inhibition of hydrolytic enzymes, formation of the germ tube and biofilm was carried out. Tests with preformed biofilm were performed to analyze biomass reduction, cell viability and biofilm breakdown by Scanning Electron Microscopy (SEM). Results demonstrate the antifungal activity of K-au at a concentration of 62.50 µg.mL-1 for all strains tested, with an action time of up to 180 minutes. As for virulence factors, K-au was not able to inhibit the secretion of enzymes, however it significantly interfered in the formation of germ tube and biofilm, suggesting its action on hyphal morphogenesis. Finally, the tests with preformed biofilm using fungicidal concentration of Kau showed a tendency to reduce cell viability, without interference in the biomass of the biofilm. This can be confirmed with the SEM images, which present a disruption of the biofilm with dead cells and the absence of hyphae. The data show the K-au anti-virulence mechanism, enabling the inhibition of polymorphism, which is crucial for the onset of infection and maintenance of C. albicans at the host sites. Therefore, PAM K-au can be considered an alternative against C. albicans, considering that its antivirulent action expands the repertoire of potential targets in these pathogens. Tipo: Dissertação Mon, 05 Apr 2021 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/83337 2021-04-05T00:00:00Z