The Relative Indirect Anthelmintic Effect of Caprine Milk on Mucins Gene Expression in Vitro Using IL-22 Treated LS174T Cells Model of Helminth Infection

Mucus secretion by intestinal goblet cells constitutes an important mechanism in TH2 response following helminth infection mediated by the key cytokine IL-22. This indirect mechanism rather than directly attacking the parasite is important in preventing helminth attachment hence promoting helminth expulsion from the intestinal tract. We hypothesized that natural products having an anthelmintic activity like caprine milk may exert similar response. Using human intestinal LS174T cells treated with IL-22 to simulate helminth infection, we tested whether or not the co-treatment with caprine milk induces MUC1, MUC3, MUC4 and MUC5B genes expression. Optimal concentrations for caprine milk was determined to be 25% and 50% from cell viability assay. IL-22 induced helminth infection model was confirmed. However, the indirect anthelmintic effect of caprine milk was only relative as treatment of caprine milk in LS174T cells and IL-22 in vitro did not significantly induce MUC1, MUC3, MUC4 and MUC5B genes expression when compared to treatment with IL-22 alone. In conclusion, caprine milk was not significantly associated with the mechanism of increased mucus production through upregulation of mucin genes by intestinal cells. Caprine milk may possess direct anthelmintic effect rather than indirect.</jats:p

Investigation of Human Albumin-Induced Circular Dichroism in Dansylglycine

Induced circular dichroism (ICD), or induced chirality, is a phenomenon caused by the fixation of an achiral substance inside a chiral microenvironment, such as the hydrophobic cavities in proteins. Dansylglycine belongs to a class of dansylated amino acids, which are largely used as fluorescent probes for the characterization of the binding sites in albumin. Here, we investigated the ICD in dansylglycine provoked by its binding to human serum albumin (HSA). We found that the complexation of HSA with dansylglycine resulted in the appearance of an ICD band centred at 346 nm. Using this ICD signal and site-specific ligands of HSA, we confirmed that dansylglycine is a site II ligand. The intensity of the ICD signal was dependent on the temperature and revealed that the complexation between the protein and the ligand was reversible. The induced chirality of dansylglycine was susceptive to the alteration caused by the oxidation of the protein. A comparison was made between hypochlorous acid (HOCl) and hypobromous acid (HOBr), and revealed that site II in the protein is more susceptible to alteration provoked by the latter oxidant. These findings suggest the relevance of the aromatic amino acids in the site II, since HOBr is a more efficient oxidant of these residues in proteins than HOCl. The three-dimensional structure of HSA is pH-dependent, and different conformations have been characterised. We found that HSA in its basic form at pH 9.0, which causes the protein to be less rigid, lost the capacity to bind dansylglycine. At pH 3.5, HSA retained almost all of its capacity for binding to dansylglycine. Since the structure of HSA at pH 3.5 is expanded, separating the domain IIIA from the rest of the molecule, we concluded that this separation did not alter its binding capacity to dansylglycine