Potential of polyphenols in curbing quorum sensing and biofilm formation in Gram-negative pathogens

Polyphenols are the secondary metabolic products of plants and are considered as active constituents to possess therapeutic effects. To date, a vast number of scientific literature addressed the potential of polyphenols as bio-efficient compounds owing to their structural diversity. Due to the presence of several hydroxyl groups, they are metabolized quickly due to conjugation reaction and thus, readily produce toxic metabolites as a defense material against many pathogens, reflecting their safety strategy. This review focuses on the anti-quorum sensing and biofilm inhibition activity of polyphenols, which display their potential to treat bacterial infections by combating the virulence caused by pathogenic agents. Thus, for mitigating quorum sensing-controlled pathogenesis, the use of polyphenol-based phytochemicals holds immense potential to cure infections. The application of polyphenol as sensitizing agent/ adjuvant therapeutics which act in synergism with antibiotics is highly remarkable.

Antioxidant, cytotoxic, and anti-venom activity of Alstonia parvifolia Merr. Bark

Objective: To evaluate antioxidant, cytotoxic, and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr. Methods: Gas chromatography-mass spectrometry (GC-MS) and energy dispersive X-ray analyses were accomplished to characterize the chemical constituents of Alstonia parvifolia. Biochemical characterization was evaluated using an inhibitory phospholipase A 2 (PLA 2) assay, DPPH, and cytotoxicity assays. Using the constituents listed in the GC-MS analyses, molecular docking was conducted to inspect the binding energies between the chosen compounds and selected PLA 2 isoforms. Results: GC-MS analyses showed that the Alstonia parvifolia crude extract consisted predominantly of acetylmarinobufogenin (14.89%), γ-sitosterol (10.44%), 3-O-methyl-D-glucose (5.88%), 3,5-dimethoxy-4-hydroxyphenylacetic acid (5.30%), (2α,5α)-17-methoxyaspidofractinin-3-one (AFM) (4.08%), and 2,3,5,6,7,8,9-heptahydro-1-phenyl-5-(p-chlorophenylimino)-1H-benzo[e] [1],[4] thiazepine (HPT) (1.37%). The principal elemental components of Alstonia parvifolia were Ca (4.012%) and K (1.496%), as exhibited by energy dispersive X-ray examination. Alstonia parvifolia showed significant free radical scavenging ability (IC 50: 0.287 mg/mL) and was non-cytotoxic to normal HDFn cells (IC 50 >100 μg/mL). Moreover, Alstonia parvifolia was favorably cytotoxic to MCF-7 (IC 50: 4.42 μg/mL), followed by H69PR, HT-29, and THP-1, with IC 50 values of 4.94, 5.07, and 6.27 μg/mL, respectively. Alstonia parvifolia also displayed notable inhibition against PLA 2 activity of Naja philippinensis Taylor venom with IC 50 of (15.2 ± 1.8) μg/mL. Docking and cluster analyses projected negative binding energies from AFM (-6.36 to -9.68 kcal/mol), HPT (-7.38 to -9.77 kcal/ mol), and acetylmarinobufogenin (-7.22 to -9.59 kcal/mol). These calculations were for the particular interactions of Alstonia parvifolia constituents to PLA 2 homologues where the utmost affinity was detected in HPT owing to the dipole interactions with amino acid residues. Conclusions: The bark extract of Alstonia parvifolia shows great potential as an anti-venom agent due to its low cytotoxic profile, remarkable PLA 2 inhibition, and docking binding energies between its bioactive constituents and PLA 2 homologues.

Potential of polyphenols in curbing quorum sensing and biofilm formation in Gram-negative pathogens

Polyphenols are the secondary metabolic products of plants and are considered as active constituents to possess therapeutic effects. To date, a vast number of scientific literature addressed the potential of polyphenols as bio-efficient compounds owing to their structural diversity. Due to the presence of several hydroxyl groups, they are metabolized quickly due to conjugation reaction and thus, readily produce toxic metabolites as a defense material against many pathogens, reflecting their safety strategy. This review focuses on the anti-quorum sensing and biofilm inhibition activity of polyphenols, which display their potential to treat bacterial infections by combating the virulence caused by pathogenic agents. Thus, for mitigating quorum sensing-controlled pathogenesis, the use of polyphenol-based phytochemicals holds immense potential to cure infections. The application of polyphenol as sensitizing agent/ adjuvant therapeutics which act in synergism with antibiotics is highly remarkable.

Antioxidant, cytotoxic, and anti-venom activity of Alstonia parvifolia Merr. Bark

Objective: To evaluate antioxidant, cytotoxic, and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr. Methods: Gas chromatography-mass spectrometry (GC-MS) and energy dispersive X-ray analyses were accomplished to characterize the chemical constituents of Alstonia parvifolia. Biochemical characterization was evaluated using an inhibitory phospholipase A 2 (PLA 2) assay, DPPH, and cytotoxicity assays. Using the constituents listed in the GC-MS analyses, molecular docking was conducted to inspect the binding energies between the chosen compounds and selected PLA 2 isoforms. Results: GC-MS analyses showed that the Alstonia parvifolia crude extract consisted predominantly of acetylmarinobufogenin (14.89%), γ-sitosterol (10.44%), 3-O-methyl-D-glucose (5.88%), 3,5-dimethoxy-4-hydroxyphenylacetic acid (5.30%), (2α,5α)-17-methoxyaspidofractinin-3-one (AFM) (4.08%), and 2,3,5,6,7,8,9-heptahydro-1-phenyl-5-(p-chlorophenylimino)-1H-benzo[e] [1],[4] thiazepine (HPT) (1.37%). The principal elemental components of Alstonia parvifolia were Ca (4.012%) and K (1.496%), as exhibited by energy dispersive X-ray examination. Alstonia parvifolia showed significant free radical scavenging ability (IC 50: 0.287 mg/mL) and was non-cytotoxic to normal HDFn cells (IC 50 >100 μg/mL). Moreover, Alstonia parvifolia was favorably cytotoxic to MCF-7 (IC 50: 4.42 μg/mL), followed by H69PR, HT-29, and THP-1, with IC 50 values of 4.94, 5.07, and 6.27 μg/mL, respectively. Alstonia parvifolia also displayed notable inhibition against PLA 2 activity of Naja philippinensis Taylor venom with IC 50 of (15.2 ± 1.8) μg/mL. Docking and cluster analyses projected negative binding energies from AFM (-6.36 to -9.68 kcal/mol), HPT (-7.38 to -9.77 kcal/ mol), and acetylmarinobufogenin (-7.22 to -9.59 kcal/mol). These calculations were for the particular interactions of Alstonia parvifolia constituents to PLA 2 homologues where the utmost affinity was detected in HPT owing to the dipole interactions with amino acid residues. Conclusions: The bark extract of Alstonia parvifolia shows great potential as an anti-venom agent due to its low cytotoxic profile, remarkable PLA 2 inhibition, and docking binding energies between its bioactive constituents and PLA 2 homologues.

La carga de la enfermedad en países de América Latina / Burden of disease in Latin America

OBJETIVO. Describir los estudios de carga de la enfermedad realizados en la región e identificar las principales prioridades en salud a partir del indicador años de vida saludable perdidos (AVISA). MATERIAL Y MÉTODOS: Mediante el uso de AVISA, identificar la carga de enfermedad en los distintos países. RESULTADOS: Los AVISA destacan la emergencia de los trastornos mentales, la diabetes mellitus en las mujeres y los trastornos por consumo de alcohol y lesiones en los hombres. CONCLUSIONES: América Latina es la región con más estudios nacionales de carga de la enfermedad realizados con una metodología estandarizada, que permiten identificar problemas de salud que están presionando a los servicios de atención; por ello estos resultados constituyen un elemento a tomar en cuenta en el establecimiento de políticas públicas en cada país.

OBJECTIVE: To describe the burden of disease studies made in the region, identify the main priorities in health from the indicator Disability Adjusted Life Years (DALYs). MATERIAL AND METHODS: By the use of DALYs identify the burden of disease in the countries in the network. RESULTS: DALYs emphasize the emergency of mental disorders, diabetes mellitus in women and the disorders associated with alcohol consumption and injuries in men. CONCLUSIONS: Latin America is the region with more national studies of burden of disease, using a standardized methodology, that allows identifying new health priorities which are pressing to the health services; for that reason these results constitute an element to take into account in the establishment of public policies in each country.

Alcohol consumption and pregnancy in the Mexican national addiction survey

En 1988 la Dirección General de Epidemiología y el Instituto Mexicano de Psiquiatría llevaron a cabo la primera Encuesta Nacional de Adicciones (ENA), que proporciona información a nivel nacional y regional sobre el uso de alcohol, tabaco y drogas ilícitas. La ENA incluye una submuestra de mujeres que se embarazaron alguma vez en la vida. Se obtuvieron 5.234 respuestas afirmativas a la pregunta de se alguma vez se habían embarazado. A este grupo se les perguntó si en su último embarazo tuvieron un aborto espontáneo, un bebe nacido muerto o un bebe con anomalías congênitas. La prevalencia de aborto espontáneo fue de 3,8 por ciento, 1,2 por ciento de nascidos muertos y 1,1 por ciento de anomalías congénitas. Se utilizaron modelos de regressión logística múltiple para analizar el papel del consumo de bebidas alcohólicas sobre estos problemas. El consumo de alcohol durante el embarazo sólo se asoció con la prevalencia de anomalías congénitas, con una razón de prevalencia de 3,4. Entre las bebedoras habituales de alcohol en los últimos 12 meses, sólo las mujeres que se ubicaron en la más alta categoría de consumo mostraron relaciones importantes con los tres probemas mencionados. Se sugiere la necessidad de realizar estudios de seguimento para llegar a conclusiones más definitivas.