Anti-inflammatory, Antioedema and Gastroprotective Activities of Aristotelia chilensis Extracts, Part 2.

Contexto: ―Chilean Black-berry” Aristotelia chilensis es un fruto silvestre que crece en el sur de Chile. Este fruto posee una fuerte actividad antioxidante y comunmente es usado en alimentos y bebidas en Chile. Objetivo: Se investigo la actividad anti-inflamatoria y gastroprotectora de los extractos, fracciones y subfracciones de este fruto y son informados aqui por primera vez. Materiales y métodos: Los extractos, fracciones y subfracciones fueron analizados por su efecto sobre la inflamación en pata de rata a través de la inducción con carragenina en dosis sencillas. Ademas se investigo la actividad gastroprotectora sobre la mucosa del estomago de rata. Resultados: Los resultados muestran que el extracto B, la fraccion F-3, F-4, y ovatifolina, quercetina, myricetina, luteolina y diosmetina, que se usaron como muestras patrones, fueron las mas activas junto con aquellas subfracciones ricas en compuestos fenolicos. Asi, SF11-SF15, SF16-SF20, y SF21-SF25 mostraron ser las mejores subfracciones inhibitorias en una forma similar a indometacina un conocido inhibidor selectivo de COX. Los resultados demuestran que estas muestras inhiben fuertemente la inflamacion inducida en el modelo del edema en pata de rata. Discusión y conclusión: Estos hallazgos demuestran que los frutos y sus constituyentes de A. chilensis poseen una excelente actividad anti-inflamatoria y gastroprotectora, y asi tienen un gran potencial como una fuente de productos naturales saludables. Adicionalmente, estos hallazgos muestran que los flavonoides, acidos fenolicos y antocianinas presentes en este fruto podrian ser los responsables de la actividad nutraceutica.Context: “Chilean black-berry” Aristotelia chilensis is a wild fruit that grows in Southern Chile. This fruit possesses a strong antioxidant activity and is commonly used in foods and beverages in Chile. Objective: The gastroprotective and anti-inflammatory activities of the extracts, fractions and subfractions as carrageenan- induced paw oedema in rats are reported here for the first time. Materials and methods: Extracts, fractions, subfractions and several compounds were used for measuring the effects in carrageenan-induced paw oedema inflammation of rat model and the gastroprotective activity was analyzed. Results: The results showed that extract B, fraction F-4, and ovatifolin, quercetin, myricetin, luteolin and diosmetin used as pattern compounds were the most active samples together with those subfractions rich in aglycone and phenolic compounds. Thus, SF11-SF15, SF16-SF20, and SF21-SF25 showed the best subfractions inhibitors in similar form to indomethacin, a known selective COX inhibitor. Results demonstrated that these samples strongly inhibited the carrageenan-induced inflammation in paw of the rat oedema model. Discussion and conclusion: These findings demonstrate that the fruits and their constituents of A. chilensis are anti-inflammatory and gastroprotective and thus have great potential as nutraceutical

Plant Growth Inhibitory Activity of N,N´-di-(4-R-phenyl)-alkanediamides [Actividad inhibitoria de crecimiento de plantas de N,N’-di-(4-R-phenyl)-alcanodiamidas]

Diamidas son una clase de metabolitos que estan presentes en plantas perteneciente a la familia de la Meliaceas, en Aglaia por ejemplo, poseen un amplio cuerpo de actividades biologicas, siendo la insecticida y la herbicida dos de las mas importantes. En nuestro programa para la busqueda de pesticidas botanicos, una serie de N,N’-di-(4-R-phenyl)-alkanodiamidas se evaluo para su actividad herbicida. Muchos de los analogos exhibieron desde buenas a moderadas actividades, tanto como pre-emergentes como post-emergentes y ademas se encontro que inhiben el metabolismo pre-emergente energetico de malezas. La relacion estructura-actividad fue probada por sustitución sobre al anillo aromatico. Entre las variaciones investigadas, se encontro que la maxima actividad herbicida se obtuvo por sustitución de F, CN y Br en la porcion aromatica y por n=2 del largo de la cadena alifatica. Este ultimo numero de carbonos de sustitución (n=2) fue clave para la actividad inhibitoria

Biopesticidas de origen botánico, fitoquímicos y extractos de Celastraceae, Rhamnaceae y Scrophulariaceae.

Desde la década de los 50’s en la agricultura intensiva occidental se han usado pesticidas orgánicos sintéticos que se acumulan en los suelos causando contaminación y toxicidad para todas las formas de vida debido a la baja biodegradabilidad de estos compuestos, dando origen a un recurrente fenómeno de surgimiento de nuevas generaciones resistentes a estos plaguicidas sintéticos. Por otra parte, metabolitos secundarios biosintetizados por especies vegetales, hongos y bacterias tanto terrestres como marinas, proporcionan nuevas fuentes de controladores de plagas, estos son bio-degradables.Varios de ellos presentan actividad selectiva ya que ejercen presión sobre las plagas (insectos, hongos, bacterias y virus) al estar constituidos por combinaciones de ellos actuando simultáneamente sin generación de resistencia (Saxena, 1986; Feyereisen, 1999; Eisner et al., 2004; Einhellig, 1995; Muñoz y Fajardo, 2005; Urzúa et al., 2010; Cespedes et al., 2001; 2006b; Plettner, 2002; Simmonds, 2003).Debido a la gran diversidad de plagas que causan pérdidas en la productividad agrícola (cultivos en crecimiento y granos almacenados) y al hecho de que muchos plaguicidas comerciales han perdido su registro en los últimos años, se hace necesaria la búsqueda de nuevas alternativas para el control de estos organismos

Insect Growth Regulator (IGR) effects of Eucalyptus citriodora Hook (Myrtaceae)

In addition to eucalyptin the methanol extract from leaves of Eucalyptus citriodora (Myrtaceae) afforded the known compounds apigenin, chrysin, luteolin, naringenin, quercetin; together with betulinic acid, oleanolic, ursolic acid, and two remaining complex mixtures of unidentified flavonoids and triterpenes. These compounds together with triterpenes mixtures, hexane and ethyl acetate extracts showed antifeedant, insecticidal and insect growth regulatory activities against fall armyworm [Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae)] an important pest of corn, and yellow mealworm [Tenebrio molitor (Coleoptera:Tenebrionidae)] a pest of stored grains. The most active compounds were chrysin, eucalyptin, quercetin, luteolin, and betulinic and oleanolic acids and the mixtures of flavonoids and triterpenes (M1 and M2). These compounds and mixtures had IGR activity between 0.2 to 5.0 μg/mL and insecticidal effects between 5.0 and 10.0 μg/mL.The extracts were insecticidal to larvae, with lethal doses between 20-100 μg/mL. These compounds appear to have selective effects on the pre-emergence metabolism of the Lepidoptera, since in all treatments of the larvae of S. frugiperda the pupation was shortened and this process showed precociousness in relation to control. Thus, these substances may be useful as potential natural insecticidal agents

Efectos de la solubilidad sobre la actividad antibacteriana de quitooligosacáridos modificados químicamente de origen fúngico

Quitina y quitosano son una clase de metabolitos que producen algunas especies de hongos que están asociados con plantas medicinales y comerciales, esto es por ejemplo en Mucor sp., con un amplio número de actividades biológicas, siendo la antibacteriana y antifúngica unas de las más importantes. En nuestro programa de investigación de biopesticidas y compuestos naturales, estamos estudiando quitosano obtenido de el medio de cultivo del hongo Mucor ruoxii. Quitooligosacáridos fueron preparados por hidrólisis parcial ácida de quitosano nativo y un derivado aminoglicosilado fue obtenido por aminación reductiva del quitooligosacárido. Las solubilidades de estos compuestos fueron medidas a diferentes pHs y su actividad antibacteriana frente a Escherichia coli (gram- negative) and Staphylococcus aureus (gram-positive). Quitosano y los derivados testeados exhiben una buena actividad antibacteriana frente a S. aureus

Constraining the primordial spectrum of metric perturbations from gravitino and moduli production

We consider the production of gravitinos and moduli fields from quantum vacuum fluctuations induced by the presence of scalar metric perturbations at the end of inflation. We obtain the corresponding occupation numbers, up to first order in perturbation theory, in terms of the power spectrum of the metric perturbations. We compute the limits imposed by nucleosynthesis on the spectral index $n_s$ for different models with constant $n_s$. The results show that, in certain cases, such limits can be as strong as $n_s<1.12$, which is more stringent than those coming from primordial black hole production.Comment: 16 pages, LaTeX, 5 figures. Corrected figures, new references included. Final version to appear in Phys. Rev.

Volatile organic compounds from Pachyrhizus ferrugineus and Pachyrhizus erosus (Fabaceae) leaves

In México, Pachyrhizus erosus (Fabaceae) commonly called "jícama", is widely known for its edible tubers. It is cultivated since the pre-Columbian period, and the powdered seeds have been used for the treatment of mange, lice, and fleas, due to their content of rotenone, a well-known insecticidal compound. On the other hand, P. ferrugineus, a wild species can only be found in the Tropical Forests, and has no commercial value. It is known that plants release volatile organic compounds (VOCs) showing qualitative and quantitative differences if are wild or cultivated. VOCs are also involved as repelling or attracting chemical signals to insect herbivores, and their natural enemies. Until now, the VOCs of the leaves of P. erosus and P. ferrugineus have not been investigated. In the present contribution the VOCs of both species were characterized by headspace solid-phase (HS-SPME) extraction and gas chromatography-mass spectrometry (GC-MS-TOF). In P. erosus 21 VOCs were found, being the most abundant: cyclohexanone (32.8%), 3-hexen-1-ol (Z) (32.7%), 3-hexenal (Z) (10.5%). The majoritarian compounds were C6 or C5 derivatives In P. ferrugineus, the most abundant VOCs were: 5-hexene-1-ol acetate (51.5%), undecanal (22.4%), 2-hepten-1-al (14.5%). The majoritarian compounds were C6, C7 or C11 derivatives

Photoprotective effect of verbascoside from Buddleja cordata in SKH-1 mice exposed to acute and chronic UV-B radiation

Ultraviolet radiation (UVR) is involved in both sunburn and the development of skin cancer, which has a high incidence worldwide. Strategies to reduce these effects include the use of photoprotective substances. The aim of this work was to investigate the photoprotective effect of verbascoside isolated from the methanolic extract of Buddleja cordata (BCME) in SKH-1 mice exposed to acute and chronic UV-B radiation. The mouse dorsal area was evaluated macroscopically and microscopically for diagnosis; verbascoside penetration into mouse skin was investigated in vivo by the tape stripping method. After acute UV-B exposure, 100% of irradiated mice that had been protected with verbascoside showed no signs of sunburn or of inflammatory processes. After chronic exposure, 100% of unprotected mice showed skin carcinomas; in contrast, in mice topically treated with either BCME or verbascoside, the presence of lesions was decreased by 90%. These results prove that verbascoside penetrates through the skin of mice and suggest that verbascoside and BCME may potentially prevent photodamage on mice’s skin after acute and chronic UVR exposure

SARS-CoV-2 viral load in nasopharyngeal swabs is not an independent predictor of unfavorable outcome

The aim was to assess the ability of nasopharyngeal SARS-CoV-2 viral load at first patient’s hospital evaluation to predict unfavorable outcomes. We conducted a prospective cohort study including 321 adult patients with confirmed COVID-19 through RT-PCR in nasopharyngeal swabs. Quantitative Synthetic SARS-CoV-2 RNA cycle threshold values were used to calculate the viral load in log10 copies/mL. Disease severity at the end of follow up was categorized into mild, moderate, and severe. Primary endpoint was a composite of intensive care unit (ICU) admission and/or death (n = 85, 26.4%). Univariable and multivariable logistic regression analyses were performed. Nasopharyngeal SARS-CoV-2 viral load over the second quartile (≥ 7.35 log10 copies/mL, p = 0.003) and second tertile (≥ 8.27 log10 copies/mL, p = 0.01) were associated to unfavorable outcome in the unadjusted logistic regression analysis. However, in the final multivariable analysis, viral load was not independently associated with an unfavorable outcome. Five predictors were independently associated with increased odds of ICU admission and/or death: age ≥ 70 years, SpO2, neutrophils > 7.5 × 103/µL, lactate dehydrogenase ≥ 300 U/L, and C-reactive protein ≥ 100 mg/L. In summary, nasopharyngeal SARS-CoV-2 viral load on admission is generally high in patients with COVID-19, regardless of illness severity, but it cannot be used as an independent predictor of unfavorable clinical outcome

Dendritic cell deficiencies persist seven months after SARS-CoV-2 infection

Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 infection induces an exacerbated inflammation driven by innate immunity components. Dendritic cells (DCs) play a key role in the defense against viral infections, for instance plasmacytoid DCs (pDCs), have the capacity to produce vast amounts of interferon-alpha (IFN-α). In COVID-19 there is a deficit in DC numbers and IFN-α production, which has been associated with disease severity. In this work, we described that in addition to the DC deficiency, several DC activation and homing markers were altered in acute COVID-19 patients, which were associated with multiple inflammatory markers. Remarkably, previously hospitalized and nonhospitalized patients remained with decreased numbers of CD1c+ myeloid DCs and pDCs seven months after SARS-CoV-2 infection. Moreover, the expression of DC markers such as CD86 and CD4 were only restored in previously nonhospitalized patients, while no restoration of integrin β7 and indoleamine 2,3-dyoxigenase (IDO) levels were observed. These findings contribute to a better understanding of the immunological sequelae of COVID-19