Extra Virgin Oil Polyphenols Improve the Protective Effects of Hydroxytyrosol in an In Vitro Model of Hypoxia-Reoxygenation of Rat Brain

Hydroxytyrosol (HT) is the component primarily responsible for the neuroprotective effect of extra virgin olive oil (EVOO). However, it is less effective on its own than the demonstrated neuroprotective effect of EVOO, and for this reason, it can be postulated that there is an interaction between several of the polyphenols of EVOO. The objective of the study was to assess the possible interaction of four EVOO polyphenols (HT, tyrosol, dihydroxyphenylglycol, and oleocanthal) in an experimental model of hypoxia-reoxygenation in rat brain slices. The lactate dehydrogenase (LDH) efflux, lipid peroxidation, and peroxynitrite production were determined as measures of cell death, oxidative stress, and nitrosative stress, respectively. First, the polyphenols were incubated with the brain slices in the same proportions that exist in EVOO, comparing their effects with those of HT. In all cases, the cytoprotective and antioxidant effects of the combination were greater than those of HT alone. Second, we calculated the concentration–effect curves for HT in the absence or presence of each polyphenol. Tyrosol did not significantly modify any of the variables inhibited by HT. Dihydroxyphenylglycol only increased the cytoprotective effect of HT at 10 μM, while it increased its antioxidant effect at 50 and 100 μM and its inhibitory effect on peroxynitrite formation at all the concentrations tested. Oleocanthal increased the cytoprotective and antioxidant effects of HT but did not modify its inhibitory effect on nitrosative stress. The results of this study show that the EVOO polyphenols DHPG and OLC increase the cytoprotective effect of HT in an experimental model of hypoxia-reoxygenation in rat brain slices, mainly due to a possibly synergistic effect on HT’s antioxidant action. These results could explain the greater neuroprotective effect of EVOO than of the polyphenols alone

The Effect of the Extra Virgin Olive Oil Minor Phenolic Compound 3′,4′-Dihydroxyphenylglycol in Experimental Diabetic Kidney Disease

The aim of this study was to analyze the possible nephroprotective effect of 3’,4’-dihydroxyphenylglycol (DHPG), a polyphenolic compound of extra virgin olive oil (EVOO), on renal lesions in an experimental model of type 1 diabetes. Rats were distributed as follows: healthy normoglycemic rats (NDR), diabetic rats treated with saline (DR), and DR treated with 0.5 mg/kg/day or 1 mg/kg/day of DHPG. DR showed a significantly higher serum and renal oxidative and nitrosative stress profile than NDR, as well as reduced prostacyclin production and renal damage (defined as urinary protein excretion, reduced creatinine clearance, increased glomerular volume, and increased glomerulosclerosis index). DHPG reduced the oxidative and nitrosative stress and increased prostacyclin production (a 59.2% reduction in DR and 34.7–7.8% reduction in DHPG-treated rats), as well as 38–56% reduction in urinary protein excretion and 22–46% reduction in glomerular morphological parameters (after the treatment with 0.5 or 1 mg/kg/day, respectively). Conclusions: DHPG administration to type 1-like diabetic rats exerts a nephroprotective effect probably due to the sum of its antioxidant (Pearson’s coefficient 0.68–0.74), antinitrosative (Pearson’s coefficient 0.83), and prostacyclin production regulator (Pearson’s coefficient 0.75) effects.This study was supported, in part, by the Consejería de Salud. Junta de Andalucía (Spain), Proyectos de Investigación en Salud [Regional Ministry of Health. Junta de Andalucía (Spain), Health Research Projects] (PI-0129-2017). Partial funding for open access charge: Universidad de Málag

Sinergismo entre 3,4-dihidroxifenilglicol e hidroxitirosol sobre biomarcadores cardiovasculares, estrés oxidativo y nitrosativo en un modelo experimental de Diabetes Mellitus tipo 1.

Resumen Póster: Objetivo El objetivo de este estudio fue evaluar el efecto sinérgico de dos polifenoles del aceite de oliva virgen extra, 3,4,-dihidroxifenilglicol (DHPG) e hidroxitirosol (HT), sobre biomarcadores cardiovasculares en un modelo experimental de Diabetes Mellitus tipo 1. Material y Métodos Se estudiaron siete grupos de animales: (1) ratas no diabéticas (NDR), (2) ratas diabéticas (DR), (3) DR tratadas con HT (5 mg/kg/día), (4) DR tratadas con DHPG (0,5 mg/kg/día), (5) DR tratadas con DPHG (1 mg/kg/día), (6) DR tratadas con HT + DHPG (0,5 mg/kg/día), y (7) DR tratadas con HT + DHPG (1 mg/kg/día). Se analizaron algunos biomarcadores cardiovasculares (agregación plaquetaria, tromboxano B2, prostaciclina, mieloperoxidasa y VCAM-1, variables de estrés oxidativo (peroxidación lipídica, glutatión, actividad antioxidante total, 8-isoprostanos, 8-hidroxi-2-deoxiguanosina y LDL oxidada), y estrés nitrosativo (3-nitrotirosina). Resultados Los animales diabéticos mostraron un desequilibrio en todas las variables analizadas. HT ejerció un efecto regulador a la baja sobre los biomarcadores protrombóticos y antioxidantes, al tiempo que frenó el descenso de prostaciclina. DHPG presentó un perfil similar, pero cuantitativamente inferior. HT y DHPG mostraron un efecto sinérgico en la reducción de la agregación plaquetaria, la producción de prostaciclina, mieloperoxidasa, VCAM-1 y del estrés oxidativo y nitrosativo. Conclusiones Se demuestra sinergismo entre 3,4-dihidroxifenilglicol e hidroxitirosol. Este sinergismo podría ser importante para el desarrollo de aceites funcionales, enriquecidos con estos dos polifenoles en la proporción utilizada en este estudio, para la prevención de la enfermedad cardiovascular.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Efecto de 3,4-dihidroxifenilglicol, polifenol del aceite de oliva virgen extra, en la nefropatía diabética experimental.

Objetivo: El objetivo de este estudio fue analizar el efecto nefroprotector de 3',4'-dihidroxifenilglicol (DHPG), un compuesto polifenólico del aceite de oliva virgen extra (AOVE), sobre las lesiones renales en un modelo experimental de diabetes tipo 1. Material y Métodos: Estudio ex vivo mediante modelo experimental de Diabetes Mellitus tipo 1 en ratas Wistar. Grupos: ratas normoglucémicas (NDR), ratas diabéticas (DR) tratadas con solución salina, y DR tratadas con DHPG (0,5 mg/kg/día o 1 mg/kg/día). Valoración del estrés oxidativo: determinación de malondialdehído (MDA), capacidad antioxidante total, glutatión, 3-nitrotirosina, 8-isoprostano, 8-hidroxi-2-deoxiguanosina, 11-dehidrotromboxano B2 y 6-keto-prostaglandina F1, en suero, orina y tejido renal. Determinación del perfil renal (aclaramiento de creatinina) y las concentraciones de glucosa. Análisis morfométrico de secciones de riñón teñidas con hematoxilina-eosina y ácido peryódico de Schiff (PAS): volumen glomerular y glomeruloesclerosis. Resultados: Las DR mostraron un perfil de estrés oxidativo y nitrosativo sérico y renal significativamente mayor que las NDR, así como una menor producción de prostaciclina y un daño renal evidente (definido como excreción urinaria de proteínas, menor aclaramiento de creatinina, mayor volumen glomerular y mayor índice de glomeruloesclerosis). DHPG redujo el estrés oxidativo, nitrosativo (una reducción del 59,2% y del 34,7%, respectivamente, respecto a las DR no tratadas) y aumentó la producción de prostaciclina (7,8% en las ratas tratadas con DHPG). Así como, una reducción del 38-56% en la excreción urinaria de proteínas y del 22-46% en los parámetros morfológicos glomerulares (tras el tratamiento con 0,5 o 1 mg/kg/día, respectivamente).Conclusiones: La administración de DHPG a ratas diabéticas tipo 1 ejerce un efecto nefroprotector, probablemente debido a la suma de sus propiedades antioxidantes, antinitrosativas y regulador de la producción de prostaciclina.Universidad de Málaga. Campus de Excelencia

Neuroprotective Effect of 3′,4′-Dihydroxyphenylglycol in Type-1-like Diabetic Rats—Influence of the Hydroxytyrosol/3′,4′-dihydroxyphenylglycol Ratio

The aim of this study was to assess the possible neuroprotective effect of 3′,4′-dihydroxyphenylglycol (DHPG), a polyphenol from extra virgin olive oil (EVOO), in an experimental model of diabetes and whether this effect is modified by the presence of another EVOO polyphenol, hydroxytyrosol (HT). The neuroprotective effect was assessed in a hypoxia–reoxygenation model in brain slices and by quantifying retinal nerve cells. The animals were distributed as follows: (1) normoglycemic rats (NDR), (2) diabetic rats (DR), (3) DR treated with HT (5 mg/kg/day p.o.), (4) DR treated with DHPG (0.5 mg/kg/day), or (5) with 1 mg/kg/day, (6) DR treated with HT plus DHPG 0.5 mg/kg/day, or (7) HT plus 1 mg/kg/day p.o. DHPG. Diabetic animals presented higher levels of oxidative stress variables and lower numbers of neuronal cells in retinal tissue. The administration of DHPG or HT reduced most of the oxidative stress variables and brain lactate dehydrogenase efflux (LDH) as an indirect index of cellular death and also reduced the loss of retinal cells. The association of DHPG+HT in the same proportions, as found in EVOO, improved the neuroprotective and antioxidant effects of both polyphenols.This study was supported, in part, by the Consejería de Salud. Junta de Andalucía (Spain), Proyectos de Investigación en Salud [Regional Ministry of Health. Junta de Andalucía (Spain), Health Research Projects] (PI-0129-2017). Partial funding for open access charge: Universidad de Málaga

Nephroprotective Effect of the Virgin Olive Oil Polyphenol Hydroxytyrosol in Type 1-like Experimental Diabetes Mellitus: Relationships with Its Antioxidant Effect

The aim of this study was to determine whether hydroxytyrosol administration prevented kidney damage in an experimental model of type 1 diabetes mellitus in rats. Hydroxytyrosol was administered to streptozotocin-diabetic rats: 1 and 5 mg/kg/day p.o. for two months. After hydroxytyrosol administration, proteinuria was significantly reduced (67-73%), calculated creatinine clearance was significantly increased (26-38%), and the glomerular volume and glomerulosclerosis index were decreased (20-30%). Hydroxytyrosol reduced oxidative and nitrosative stress variables and thromboxane metabolite production. Statistical correlations were found between biochemical and kidney function variables. Oral administration of 1 and 5 mg/kg/day of hydroxytyrosol produced an antioxidant and nephroprotective effect in an experimental model of type 1-like diabetes mellitus. The nephroprotective effect was significantly associated with the systemic and renal antioxidant action of hydroxytyrosol, which also influenced eicosanoid production.This study was supported in part by the Consejería de Salud. Junta de Andalucía (Spain), Proyectos de Investigación en Salud (Regional Ministry of Health. Junta de Andalucía (Spain), Health Research Projects) (PI-0129-2017) and by Ministerio de Economía y Competitividad (Ministry of Economy and Competitiveness) (Spain), Centro para el Desarrollo Tecnológico Industrial (Center for the Development of Industrial Technology), FEDER Interconecta Pluri-Regional Program (Spain), (PS17173. NUTRADAF, ITC-20161265).Ye

An opportunity to emphasize the relevance of laboratory medicine

Clinical practice guidelines (CPGs) are recommendations based on a systematic review of scientific evidence that are intended to help healthcare professionals and patients make the best clinical decisions. CPGs must be evidence-based and are designed by multidisciplinary teams. The purpose of this study is to assess the topics related to the clinical laboratory addressed in CPGs and evaluate the involvement of laboratory professionals in the CPG development process

The Effect of the Extra Virgin Olive Oil Minor Phenolic Compound 3′,4′-Dihydroxyphenylglycol in Experimental Diabetic Kidney Disease

The aim of this study was to analyze the possible nephroprotective effect of 3’,4’-dihydroxyphenylglycol (DHPG), a polyphenolic compound of extra virgin olive oil (EVOO), on renal lesions in an experimental model of type 1 diabetes. Rats were distributed as follows: healthy normoglycemic rats (NDR), diabetic rats treated with saline (DR), and DR treated with 0.5 mg/kg/day or 1 mg/kg/day of DHPG. DR showed a significantly higher serum and renal oxidative and nitrosative stress profile than NDR, as well as reduced prostacyclin production and renal damage (defined as urinary protein excretion, reduced creatinine clearance, increased glomerular volume, and increased glomerulosclerosis index). DHPG reduced the oxidative and nitrosative stress and increased prostacyclin production (a 59.2% reduction in DR and 34.7–7.8% reduction in DHPG-treated rats), as well as 38–56% reduction in urinary protein excretion and 22–46% reduction in glomerular morphological parameters (after the treatment with 0.5 or 1 mg/kg/day, respectively). Conclusions: DHPG administration to type 1-like diabetic rats exerts a nephroprotective effect probably due to the sum of its antioxidant (Pearson’s coefficient 0.68–0.74), antinitrosative (Pearson’s coefficient 0.83), and prostacyclin production regulator (Pearson’s coefficient 0.75) effects

Synergistic Effect of 3',4'-Dihidroxifenilglicol and Hydroxytyrosol on Oxidative and Nitrosative Stress and Some Cardiovascular Biomarkers in an Experimental Model of Type 1 Diabetes Mellitus

The objective of this study was to assess a possible synergistic effect of two extra-virgin olive oil polyphenols, 3,4,-dyhydroxyphenylglycol (DHPG) and hydroxytyrosol (HT), in an experimental model of type 1 diabetes. Seven groups of animals were studied: (1) Nondiabetic rats (NDR), (2) 2-month-old diabetic rats (DR), (3) DR treated with 5 mg/kg/day p.o. HT, (4) DR treated with 0.5 mg/kg/day p.o. DHPG, (5) DR treated with 1 mg/kg/day p.o. DHPG, (6) DR treated with HT + DHPG (0.5), (7) DR treated with HT + DHPG (1). Oxidative stress variables (lipid peroxidation, glutathione, total antioxidant activity, 8-isoprostanes, 8-hydroxy-2-deoxyguanosine, and oxidized LDL), nitrosative stress (3-nitrotyrosine), and some cardiovascular biomarkers (platelet aggregation, thromboxane B2, prostacyclin, myeloperoxidase, and vascular cell adhesion protein 1 (VCAM-1)) were analyzed. The diabetic animals showed an imbalance in all of the analyzed variables. HT exerted an antioxidant and downregulatory effect on prothrombotic biomarkers while reducing the fall of prostacyclin. DHPG presented a similar, but quantitatively lower, profile. HT plus DHPG showed a synergistic effect in the reduction of oxidative and nitrosative stress, platelet aggregation, production of prostacyclin, myeloperoxidase, and VCAM-1. This synergism could be important for the development of functional oils enriched in these two polyphenols in the proportion used in this study.This study was supported, in part, by the Consejería de Salud. Junta de Andalucía (Spain), Proyectos de Investigación en Salud [Regional Ministry of Health. Junta de Andalucía (Spain), Health Research Projects] (PI-0129-2017)Ye

Guías de práctica clínica: oportunidad para visibilizar la importancia de la medicina del laboratorio

Las guías de práctica clínica (GPC) son recomendaciones desarrolladas de forma sistemática para ayudar a profesionales y pacientes en la toma de decisiones sobre la atención sanitaria más apropiada. Destacan entre sus características que deben basarse en la evidencia científica y estar elaboradas por equipos multidisciplinares. El objetivo de este estudio fue evaluar, en GPC, el contenido de la información sobre aspectos propios del laboratorio clínico y la participación de los profesionales del laboratorio en su elaboración