A carregar...
Publicação
Estudos de permeabilidade intestinal com co-culturas de células Caco-2/HT29-MTX-E12
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 2.18 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
The intestinal barrier provides four levels of protection. However, food contaminants can compromise this protective role by altering the membrane’s permeability, posing a health hazard. This study had as its main objective the participation in the harmonisation assays to study intestinal permeability, by INFOGEST. An in vitro cellular monolayer model was applied, with HT29- MTX-E12 monocultures and Caco-2/HT29-MTX-E12 (9:1) co-cultures, using reference intestinal transport markers: Lucifer Yellow (LY) and Propranolol. The intestinal barrier’s integrity was verified by the transepithelial electrical resistance (TEER), apparent permeability coefficients (Papp) for both markers and basal recovery (%) for LY. The TEER values obtained for the co-cultures (450,6-1287,3 Ωcm²) were higher than the monocultures (108,5-781,8 Ωcm²), and the transport assays showed the functional membranes obtained. For LY, the Papp values obtained were close to 1x10⁻⁶ cm/s, and basal recovery ranged between 0 and 1% for both cultures. Regarding Propranolol, the Papp values for the co-cultures (24x10⁻⁶ cm/s) were higher than the monocultures (8x10⁻⁶ cm/s). Furthermore, cytotoxicity assays (MTT) were performed with natural toxins, including the mycotoxin Patulin (PAT), and the ciguatoxins CTX3C and CTX1B, in order to verify the concentrations that should be used in future transport assays. Patulin was used as a positive control, showing high cytotoxicity at 200 μM and 500 μM. CTX3C’s cytotoxicity at 5 ng/mL was linked to the solvent’s high concentration (5% DMSO). On the CTX1B’s assay, with a low concentration of solvent (0,25% DMSO), there was a significant increase in the cellular viability at 5 ng/mL. Additionally, a literature review was conducted on the toxicology of ciguatoxins due to their geographic expansion in Europe, their public health relevance, and the limited knowledge regarding their mechanism of toxicity.
Descrição
Tese de Mestrado, Biologia Humana e Ambiente, 2026, Universidade de Lisboa, Faculdade de Ciências
Palavras-chave
Caco-2 HT29-MTX-E12 intestinal permeability MTT ciguatoxins