Why proanthocyanidins elute at increasing order of molecular masses when analysed by normal phase high performance liquid chromatography? Considerations of use

Although it is widely known that proanthocyanidins elute at an increasing order of molecular masses when analysed by normal phase high performance liquid chromatography (NP-HPLC), there is no a consistent explanation of the mechanisms of their separation until now. Therefore, the aim of the present study was to give a reliable response to this question, using a complex procyanidin-rich grape seed extract. For this, an off-column static simulation of extract injection and a fragmented-column dynamic procyanidin location tests were studied to show their precipitation in an aprotic solvent, besides another off-column static simulation and multiple contact dynamic solubilisation tests to confirm procyanidin redissolution in an aprotic/protic solvent system. The results showed that separation of procyanidins in the aprotic/protic solvent system of Diol-NP-HPLC was governed by precipitation/redissolution mechanism, that could be extended to all known plant proanthocyanidin homopolymers, including hydrolysable tannins, if they are able to accomplish this condition. However, separation of monomer species, namely catechins and some hydroxybenzoic acids, was based on classic adsorption/partition mechanism. Other factors, such as analyte solubility, chromatographic conditions and sample preparation, that affect the viability of proanthocyanidin analysis by NP-HPLC were stand out and guidelines for its durable and reproducible use were definedWe thank the Consejería de Educación e Investigación from Comunidad de Madrid Consejería de Ciencia, Universidades e Innovación (ref. IND2019/BIO-17238) for the financial support of this study and the fellow-ship grant of Esperanza Guerrero-Hurtado and contract of Alba Gutiérrez-Doci

Olive leaf as a source of antibacterial compounds active against antibiotic-resistant strains of Campylobacter jejuni and Campylobacter coli

Campylobacter spp. are the main cause of bacterial gastroenteritis worldwide, and broiler chicks are the main vector of transmission to humans. The high prevalence of Campylobacter in poultry meat and the increase of antibiotic resistant strains have raised the need to identify new antimicrobial agents. For this reason, the aim of the current study was to evaluate the antibacterial activity of two extracts of olive leaf against antibiotic-resistant Campylobacter strains (C. jejuni and C. coli) isolated from poultry food chain. The extracts of olive leaf (E1 and E2) were markedly different in their chemical compositions. While E1 was composed predominantly of highly hydrophilic compounds such as hydroxytyrosol and hydroxytyrosol glucosides (14,708 mg/100 g), E2 mainly contained moderately hydrophilic compounds, with oleuropein (20,471 mg/100 g) being prevalent. All Campylobacter strains exhibited similar antibiotic profiles, being resistant to ciprofloxacin and tetracycline. E1 showed strong antibacterial activity and reduced bacterial growth from 4.12 to 8.14 log CFU/mL, depending on the strain. Hydroxytyrosol was the main compound responsible, causing the inhibition of growth of Campylobacter strains at low concentrations (0.1–0.25 mg/mL). E2 demonstrated a lower antibacterial effect than E1, reducing growth from 0.52 to 2.49 log CFU/mL. The results of this study suggest that the optimization of the composition of olive-leaf extracts can provide improved treatment results against Campylobacter strain

Olive-leaf extracts modulate inflammation and oxidative stress associated with human H. pylori infection

Helicobacter pylori (H. pylori) is one of the major human pathogens and the main cause of pathological damages that can progress from chronic gastritis to gastric cancer. During the coloni-zation of gastric mucosa, this bacterium provokes a strong inflammatory response and subsequent oxidative process, which are associated with tissue damage. Therefore, the objective of this research was to evaluate the ability of two olive-leaf extracts (E1 and E2) to modulate the inflammatory response and oxidative stress in H. pylori-infected human gastric AGS cells. The obtained results showed that both extracts significantly decreased interleukin-8 (IL-8) secretion and reactive oxygen species (ROS) production in human gastric AGS cells. Both extracts also showed antibacterial activity against different H. pylori strains. HPLC-PAD-MS characterization demonstrated that extract E1 was mainly composed of highly hydrophilic compounds, such as hydroxytyrosol (HT) and its glu-cosides, and it was the most effective extract as an antibacterial agent. In contrast, extract E2 was composed mostly of moderately hydrophilic compounds, such as oleuropein (OLE), and it was more effective than extract E1 as an anti-inflammatory agent. Both extracts exhibited similar potential to decrease ROS production. These results show the importance of standardizing the extract composition according to the bioactive properties that should be potentiate

Pre-treatment with grape seed extract reduces inflammatory response and oxidative stress induced by helicobacter pylori infection in human gastric epithelial cells

Helicobacter pylori (H. pylori) is a pathogenic bacteria identified as a potential risk factor for gastritis, gastric ulcers and gastric cancer. During the stomach colonization, H. pylori triggers a strong inflammatory response and subsequent oxidative stress, which are associated with tissue damage. For this reason, it is of particular interest to develop alternative natural tools that enable modulation of the associated damaging immune response. With this purpose, we obtained grape seed extract (GSE) from sweet (not fermented) food grade seeds. The aim of our study was to investigate the effect of GSE and its two enriched procyanidins fractions (OPC and PPC) on the inflammatory process and oxidative stress produced by different H. pylori strains in human gastric epithelial cells (AGS). Anti-inflammatory activity was evaluated by measuring the level of interleukin-8 (IL-8) secretion. IL-8 production was significantly reduced in H. pylori-infected human gastric epithelial cells pretreated with GSE or its enriched fractions when compared with non-pre-treated infected cells (from 21.6% to 87.8%). Pre-treatment with GSE or its fractions significantly decreased intracellular reactive oxygen species (ROS) production in AGS cells after infection, depending on the H. pylori strain. Our results also showed that GSE and its fractions demonstrate antibacterial activity against all strains of H. pylori used in the study. This work demonstrates the effectiveness of GSE enriched in procyanidins against the main events associated with H. pylori infection

Colombian consensus recommendations for diagnosis, management and treatment of the infection by SARS-COV-2/ COVID-19 in health care facilities - Recommendations from expert´s group based and informed on evidence

La Asociación Colombiana de Infectología (ACIN) y el Instituto de Evaluación de Nuevas Tecnologías de la Salud (IETS) conformó un grupo de trabajo para desarrollar recomendaciones informadas y basadas en evidencia, por consenso de expertos para la atención, diagnóstico y manejo de casos de Covid 19. Estas guías son dirigidas al personal de salud y buscar dar recomendaciones en los ámbitos de la atención en salud de los casos de Covid-19, en el contexto nacional de Colombia

Evaluación de la actividad antibacteriana de un extracto de semillas de uva rico en procianidinas frente a diferentes cepas de Helicobacter pylori resistentes a antibióticos

Resumen del trabajo presentado al II Congreso Anual Internacional de Estudiantes de Doctorado, celebrado en la Universidad Miguel Hernández (Elche) del 3 al 4 de febrero de 2022.Peer reviewe

In vitro antioxidant and anti-inflammatory properties of Olivulin®, a propietary blend of olive leaf, acerola and common madder extracts and matcha tea power

Trabajo presentado a las XXVI Jornadas Internacionales de Nutrición Práctica y al XV Congreso Internacional de la Sociedad Española de Dietética y Ciencias de la Alimentación, Sociedad Española de Dietética y Ciencias de la Alimentación, celebrados en Madrid del 29 al 31 de marzo de 2022.Peer reviewe

Determinación del contenido de compuestos fenólicos totales y azúcares en extractos de hoja de olivo enriquecidos

Resumen del trabajo presentado al II Congreso Anual Internacional de Estudiantes de Doctorado, celebrado en la Universidad Miguel Hernández (Elche) del 3 al 4 de febrero de 2022.Peer reviewe

Propiedades antibacterianas, antioxidantes y anti-inflamatorias de extractos de hoja de olivo frente a cepas de Helicobacter pylori resistentes a antibióticos

Trabajo presentado al XXII Congreso Nacional de Microbiología de los Alimentos, celebrado en Jaén del12 al 15 de septiembre de 2022.Helicobacter pylori (H. pylori) es uno de los principales patógenos humanos que afecta aproximadamente al 50% de la población mundial. Habitualmente para su tratamiento se utiliza una terapia basada en el uso combinado de al menos dos antibióticos diferentes. En los últimos años se han incrementado significativamente las cepas resistentes a los tratamientos con antibióticos, por lo que se requieren nuevas alternativas sostenibles para su tratamiento. Además, durante la infección por H. pylori tiene lugar a un proceso inflamatorio crónico que puede derivar en un agravamiento de los síntomas asociados a la infección. El objetivo del presente trabajo fue evaluar el efecto antibacteriano, antioxidante y anti-inflamatorio de dos extractos de hojas de olivo frente a cepas de H. pylori resistentes a antibióticos. El extracto E1, constituido principalmente por compuestos muy hidrófilos, como el hidroxitirosol y sus glucósidos, fue más eficaz como agente antibacteriano. Sin embargo, el extracto E2, compuesto principalmente por compuestos moderadamente hidrófilos, como la oleuropeína, presentó un mejor potencial anti-inflamatorio, disminuyendo de forma significativa la cantidad de citoquinas IL-8 producidas por las células gástricas previamente infectadas por H. pylori. En cuanto a la actividad antioxidante, ambos extractos mostraron un potencial similar para disminuir la producción de ROS en células gástricas infectadas. Estos resultados demuestran la importancia de estandarizar la composición del extracto de acuerdo con las propiedades bioactivas que deben potenciarse. La utilización de las hojas de olivo como fuente de compuestos bioactivos para la elaboración de extractos eficaces frente a H. pylori contribuye al desarrollo de nuevas y sostenibles estrategias de valorización de los subproductos de la industria olivarera que contribuyen al reciclado y la revalorización de los mismos.HELIFOOD (AGL2017-89566-R). MINECO. Comunidad de Madrid: IND2019/BIO-17238Peer reviewe

Antibacterial and anti-adherent properties of a grape seed extract against Helicobacter pylori

Trabajo presentado al World Microbe Forum, celebrado de forma virtual del 20 al 24 de junio de 2021.Peer reviewe