NMR Analysis of Extra Virgin Olive Oil of the Epirus Region of Greece with Emphasis on Selected Phenolic Compounds.

Extra virgin olive oil (EVOO) is recognized for its numerous health benefits, attributed to its rich phenolic components. NMR has emerged as a prevalent technique for precisely identifying these compounds. Among Mediterranean countries, Greece stands as the third-largest producer of olives, with the Epirus region notably advancing in olive cultivation, contributing significantly to the dynamic growth of the region. In this study, an NMR method was employed based on the acquisition of a 1H NMR spectrum along with multiple resonant suppression in order to increase the sensitivity. Using the above method, 198 samples of extra virgin olive oil, primarily sourced from the Epirus region, were analyzed, and both the qualitative and quantitative aspects of the phenolic compounds were obtained. In addition, we examined the effects of various factors such as variety, harvest month, and region origin on the phenolic compounds' concentration. The results revealed an average total phenolic content of 246 mg/kg, closely approaching the EU health claim limit of 250 mg/kg. Approximately 15% of the samples were confidently characterized as high-phenolic olive oil. The highest concentrations were observed in the Thesprotia samples, with several Lianolia varieties exceeding the total phenolic content of 400 mg/kg. Statistical tests demonstrated a significant influence of the olive variety and the month of fruit harvest on phenolic component concentration, followed by the region of origin. A very strong correlation was noted between the total phenolics content and the levels of oleocanthal and oleacein, with a correlation coefficient (r) of 0.924. Upon optimization of all factors affecting olive oil quality, the majority of the EVOOs from the Epirus region have the potential to be characterized as high in phenolic content.

Levels of Circulating IgM and IgY Natural Antibodies in Broiler Chicks: Association with Genotype and Farming Systems.

Naturally occurring antibodies (NAbs), which are major components of innate immunity, exist in circulation under healthy conditions without prior antigenic stimulation and are able to recognize both self- and non-self-constituents. The present study aimed at identifying potential immunological differences between commercial fast- and slow-growth broilers (n = 555) raised in conventional and free-range systems, respectively, through the use of the specificity, isotypes and levels of circulating NAbs. The possible beneficial effect of oregano-based dietary supplementation was also evaluated. To this end, serum IgM and IgY NAbs against self- (actin and DNA) and non-self- antigens (trinitrophenol and lipopolysaccharide) were measured by ELISA and further correlated with genotype, season and performance. Significantly higher levels of IgM NAbs against all antigens were found in slow-growth compared to fast-growth broilers. IgM NAb levels were also significantly increased in dietarily supplemented slow-growth broilers versus those consuming standard feed. Moreover, significantly elevated levels of anti-DNA IgY NAbs were found in fast-growth compared to slow-growth broilers, whereas the opposite was observed for anti-LPS IgY NAbs. Multivariate linear regression analysis confirmed multiple interactions between NAb levels, genotype, season and performance. Overall, serum NAbs have proven to be valuable innovative immunotools in the poultry industry, efficiently differentiating fast-growing versus slow-growing broilers, and dietary supplementation of plant extracts can enhance natural immunity.

Coordination properties of Cu(II) ions towards a phosphorylated fragment from the R1 domain of the tau protein and the effect of Ser phosphorylation on Cu(II) binding affinity.

Tau hyperphosphorylation plays a key role in Alzheimer's disease, mediating tau protein aggregation and deposition as neurofibrillary tangles in the intracellular space of neurons. The potential implications of Cu(II) ions on the disease have been studied intensively, focusing both on Cu(II)-amyloid and on Cu(II)-tau fragment interactions. Nevertheless, there is still a lack of information concerning the metal binding properties and the affinity of phosphorylated fragments of tau. In this work, the coordination properties of Cu(II) ions toward the peptides Ac-GSTENLKH-NH2 (R1) and Ac-GS(P)TENLKH-NH2 (R1P) (Ser phosphorylated analogue) were studied using potentiometric and spectroscopic (vis-EPR) methods. The above sequence belongs to the 261-268 segment of the R1 pseudorepeat of the microtubule-binding domain of the longest tau isoform. It includes both the required metal anchor site (His268) and the residue Ser262, a well-known tau phosphorylation site. There was no surprise in the coordination process of both peptides, which form 1 : 1 metal : ligand complexes and follow the already well-known binding trend (i.e., His imidazole as an anchor site followed by the deprotonation and subsequent coordination of 1-3 amide donors). The additional participation of the Glu-γ-COOH in the equatorial plane was evident for the species detected in acidic solutions, while in the pH range of 7-10, the same group occupies an axial position. The comparison of the Cu(II) binding affinities, revealed that the phosphorylated peptide (R1P) is a more effective ligand than R1 in acidic media. Above pH ∼ 7.9, the order is reversed, highlighting the role of the phosphate inter- or intra-molecular interactions in Cu(II) binding.