Antimicrobial Activity of Spanish Propolis against Listeria monocytogenes and Other Listeria Strains.

The outbreaks of Listeria associated with food consumption are increasing worldwide concurrently with public concern about the need for natural growth inhibitors. In this context, propolis seems to be a promising bioactive product collected by honeybees, due to its antimicrobial activity against different food pathogens. This study aims to evaluate the efficacy of hydroalcoholic propolis extracts for controlling Listeria under several pH conditions. The physicochemical properties (wax, resins, ashes, impurities), the bioactive compounds (phenolic and flavonoid content), and the antimicrobial activity of 31 propolis samples collected from the half North of Spain were determined. Results showed similar trends in the physicochemical composition and bioactive properties, regardless of the harvesting area. Non-limiting pH conditions (7.04, 6.01, 5.01) in 11 Listeria strains (5 from collection and 6 wild strains from meat products) exhibited MICs (Minimum inhibition concentration) and MBCs (Minimum bactericidal concentration) ranging from 39.09 to 625 µg/mL. The antibacterial activity increased under acidic pH conditions, showing a synergistic effect at pH = 5.01 (p < 0.05). These findings suggest the potential of Spanish propolis as a natural antibacterial inhibitor to control Listeria growth in food products.

Biochemical Profile and Antioxidant Properties of Propolis from Northern Spain.

The antioxidant, anti-inflammatory, and antimicrobial characteristics of propolis, a bioactive compound collected from hives, have prompted its use in the food sector in recent times. This study investigated the physicochemical characteristics, phenolic profile, and antioxidant capacity of 31 propolis extracts collected from Northern Spain. The physicochemical composition (resins, waxes, ashes mineral content, and heavy metals) was within the allowable regulatory limits. The analysis of bioactive compounds enabled the identification of 51 constituents: flavonoids (apigenin, catechin, chrysin, quercetin, and pinocembrin) and phenolic acids (caffeic, ferulic, and coumaric). The mean value of total polyphenols was 42.72 ± 13.19 Pinocembrin-Galangin Equivalents/100 g, whereas a range between 1.64 ± 0.04 and 4.95 ± 0.36 Quercetin Equivalents (QE) g/100 g was found for total flavonoids content. The determination of bioactivities revealed significant antioxidant capacity using DPPH (1114.28 ± 10.39 µM Trolox Equivalents and 3487.61 ± 318.66 µM Vitamin C Equivalents). Resin content in propolis samples was positively and significantly correlated with both polyphenols (rho = 0.365; p = 0.043) and flavonoid composition (rho = 0.615; p = 0.000) as well as the antioxidant capacity TEAC DPPH (rho = 0.415; p = 0.020). A multiple regression analysis modeled the correlation between resin composition, flavonoids, and TEAC DPPH values, yielding a significant regression equation (R2 = 0.618; F (2,28) = 22.629; p < 0.000; d = 2.299). Therefore, evaluating physicochemical parameters and biological activities provides a promising framework for predicting propolis' quality and antioxidant properties, thus suggesting its potential as a functional and bioactive compound for the food industry.

Assessment of (-) epicatechin as natural additive for improving safety and functionality in fresh "Piel de Sapo" melon juice.

Epicatechin (EC) is a very abundant flavonoid in vegetable tissues that presents high antioxidant activity in living systems. The minimum inhibitory concentration (MIC) of (-)EC was determined in three species of bacteria commonly associated with foodborne illness of plant origin: Listeria (L.) monocytogenes, Escherichia (E.) coli -serogroups O157: H7 and O111- and Bacillus (B.) cereus; two strains of probiotic-type lactic acid bacteria (PT-LAB) and two control strains. All 10 strains were assayed under three temperature conditions (30º, 10º, and 4ºC) and at each temperature under two pH conditions (6.7 and 5.5). Mean EC MIC values were generally lower at refrigeration (4º and 10ºC) temperatures and at standard pH (6.7). By inoculating with each of the strains separately, both melon juice (MJ) and MJ supplemented with EC (ECSMJ), at the accepted maximum sensorial limit, and storing them at 4ºC for 10 days; the final counts (CFU/mL) were lower for ECSMJ than for plain MJ both for pathogenic bacteria and for PT-LAB. The presence of EC during refrigerated storage counteracted the ability of MJ as a growth medium for all the pathogenic bacteria. ECSMJ increased the antioxidant activity of MJ significantly to levels similar to those of EC alone. (-) Epicathechin would be a promising ingredient for increasing the functional properties of "Piel de Sapo" MJ (phenolic compounds and antioxidant ability) while contributing to improving the safety of this type of juice during prolonged refrigerated storage at 4ºC.

Effects of dietary supplementation with lemon verbena extracts on serum inflammatory markers of multiple sclerosis patients / Efecto de la suplementación dietética con extractos de hierbaluisa en los marcadores de inflamación en suero de personas con esclerosis múltiple

Introduction: Inflammation is one of the main contributory factors to the etiopathogenesis of multiple sclerosis (MS). Dietary interventions with Lipia citriadora (lemon verbena) extracts have been proved to be effective in the prevention of inflammatory diseases. Objectives: The aim of this study is to evaluate the effect of lemon verbena supplementation in pro- and anti- inflammatory serum biomarkers of patients with different clinical subtypes of multiple sclerosis. Methods: The effect of lemon verbena supplementation (10% w/w verbascoside) was evaluated in a randomized, double-blinded placebo-controlled study with 30 participants classified in relapsing-remitting (n=10), primary progressive (n=5) and secondary progressive (n=15) MS presentations. Serum cytokine and C reactive protein levels were assessed in intervention and control groups for each MS clinical subtype after 28 days of dietary supplementation. Results: Serum levels of C reactive protein and 8 cytokines/ inflammatory (IFN-γ, IL-12, IL-23, IL-6, TNF-α, TGF-β, IL-4 and IL-10) markers were studied. Secondary progressive MS- supplemented patients showed C reactive protein concentrations significantly lower compared to the placebo group (p<0.005). IFN-γ levels decreased for all MS-treated groups whereas IL-12 diminished levels were observed for relapsing-remitting type (p<0.05). Anti-inflammatory cytokine concentrations of IL-4 (difference 2.98 ± 2.99 pg/mL) and IL-10 (difference 1.78 ± 5.54 pg/mL) increased in secondary progressive MS patients (p<0.05). Conclusion: The variation of several pro- and anti-inflammatory markers after supplementation suggests that lemon verbena extracts may affect cytokine profiles in multiple sclerosis. Further investigation on dietary components with antioxidant and anti-inflammatory properties may contribute to understand MS pathogenesis and ameliorate MS symptoms (AU)

Introducción: La inflamación es uno de los principales factores que contribuyen en la etiopatogénesis de la esclerosis múltiple (EM). Se ha demostrado que las intervenciones en la dieta con extractos de Lipia citriadora (hierbaluisa) son efectivas en la prevención de las enfermedades inflamatorias. Objectivos: El objetivo de este estudio es evaluar el efecto de la suplementación con extractos de hierbaluisa en los biomarcadores de inflamación en suero de pacientes con diferentes subtipos clínicos de esclerosis múltiple. Métodos: El efecto de la suplementación con hierbaluisa (10 % p/p verbascósido) se evaluó mediante un estudio aleatorizado de doble ciego controlado con grupo placebo, constituido por 30 participantes clasificados según la forma de presentación de EM en: remitentes-recaídas (n=10), primaria progresiva (n=5) y secundaria progresiva (n=15). Los niveles de citoquinas y proteína C reactiva en suero se valoraron en los grupos intervención y control de cada uno de los subtipos clínicos de EM después de 28 días de suplementación en la dieta. Resultados: Se estudiaron los niveles en suero de proteína C reactiva y de 8 citoquinas como biomarcadores deinflamación (IFN-γ, IL-12, IL-23, IL-6, TNF-α, TGF-β, IL-4 e IL-10). Los pacientes del grupo de intervención con EM secundaria progresiva presentaron concentraciones de proteína C reactiva significativamente más bajos comparados con el grupo placebo (p<0.005). Los niveles de IFN-γ disminuyeron en todos los grupos tratados a la vez que se detectaron niveles inferiores de IL-12 en las formas secundaria progresiva y remitente-recaídas (p<0.05). Las concentraciones de las citoquinas anti-inflamatorias: IL-4 (diferencia 2,98 ± 2,99 pg/mL) y IL-10 (diferencia 1,78 ± 5,54 pg/mL) aumentaron en los pacientes con EM secundaria progresiva (p<0.05). Conclusión: La variación en la concentración de varias citoquinas pro- y anti-inflamatorias después de la suplementación con los extractos de hierbaluisa puede afectar al perfil de las citoquinas en la esclerosis múltiple. La investigación futura de los componentes de la dieta con propiedades anti-inflamatorias y antioxidantes puede contribuir a entender la patógenesis de la esclerosis múltiple así como a disminuir sus síntomas (AU)

Effects of dietary supplementation with lemon verbena extracts on serum inflammatory markers of multiple sclerosis patients.

INTRODUCTION: Inflammation is one of the main contributory factors to the etiopathogenesis of multiple sclerosis (MS). Dietary interventions with Lipia citriadora (lemon verbena) extracts have been proved to be effective in the prevention of inflammatory diseases. OBJECTIVES: The aim of this study is to evaluate the effect of lemon verbena supplementation in pro- and anti- inflammatory serum biomarkers of patients with different clinical subtypes of multiple sclerosis. METHODS: The effect of lemon verbena supplementation (10% w/w verbascoside) was evaluated in a randomized, double-blinded placebo-controlled study with 30 participants classified in relapsing-remitting (n=10), primary progressive (n=5) and secondary progressive (n=15) MS presentations. Serum cytokine and C reactive protein levels were assessed in intervention and control groups for each MS clinical subtype after 28 days of dietary supplementation. RESULTS: Serum levels of C reactive protein and 8 cytokines/ inflammatory (IFN-γ, IL-12, IL-23, IL-6, TNF-α, TGF-ß, IL-4 and IL-10) markers were studied. Secondary progressive MS- supplemented patients showed C reactive protein concentrations significantly lower compared to the placebo group (p.

Introducción: La inflamación es uno de los principales factores que contribuyen en la etiopatogénesis de la esclerosis múltiple (EM). Se ha demostrado que las intervenciones en la dieta con extractos de Lipia citriadora (hierbaluisa) son efectivas en la prevención de las enfermedades inflamatorias. Objectivos: El objetivo de este estudio es evaluar el efecto de la suplementación con extractos de hierbaluisa en los biomarcadores de inflamación en suero de pacientes con diferentes subtipos clínicos de esclerosis múltiple. Métodos: El efecto de la suplementación con hierbaluisa (10 % p/p verbascósido) se evaluó mediante un estudio aleatorizado de doble ciego controlado con grupo placebo, constituido por 30 participantes clasificados según la forma de presentación de EM en: remitentes-recaídas (n=10), primaria progresiva (n=5) y secundaria progresiva (n=15). Los niveles de citoquinas y proteína C reactiva en suero se valoraron en los grupos intervención y control de cada uno de los subtipos clínicos de EM después de 28 días de suplementación en la dieta. Resultados: Se estudiaron los niveles en suero de proteína C reactiva y de 8 citoquinas como biomarcadores de inflamación (IFN-, IL-12, IL-23, IL-6, TNF-, TGF-, IL-4 e IL-10). Los pacientes del grupo de intervención con EM secundaria progresiva presentaron concentraciones de proteína C reactiva significativamente más bajos comparados con el grupo placebo (p.