Nitric oxide production, inhibitory, antioxidant and antimycobacterial activities of the fruits extract and flavonoid content of Schinus terebinthifolius

AbstractThe extract of the fruits from Schinus terebinthifolius Raddi, Anacardiaceae, was obtained by exhaustive extraction with methanol. Its fractions and isolated compounds were collected by fractionation with RP-2 column chromatography. The crude extract, the flavonoid fraction and the isolated compound identified as apigenin (1), were investigated regarding its inhibitory action of nitric oxide production by LPS-stimulated macrophages, antioxidant activity by DPPH and the antimycobacterial activity against Mycobacterium bovis BCG. The samples exhibited a significant inhibitory effect on the nitric oxide production (e.g., 1, IC50 19.23 ± 1.64μg/ml) and also showed antioxidant activity. In addition, S. terebinthifolius samples inhibited the mycobacterial growth (e.g., 1, IC50 14.53 ± 1.25μg/ml). The necessary concentration to produce 50% of the maximum response (IC50) of these activities did not elicit a significant cytotoxic effect when compared with the positive control (100% of lysis). The antioxidant and nitric oxide inhibition activity displayed by S. terebinthifolius corroborates its ethnopharmacological use of this specie as an anti-inflammatory. In addition, our results suggest that the flavonoids of S. terebinthifolius are responsible for the activities found. We, describe for the first time the activity against Mycobacterium bovis BCG and the inhibition of nitric oxide production for S. terebinthifolius

Secondary metabolites related to the resistance of Psidium spp. against the nematode Meloidogyne enterolobii.

The guava tree (Psidium guajava) is a tropical species native to South America and is recognized as the 11th most economically important fruit tree in Brazil. However, the presence of the nematode Meloidogyne enterolobii and the fungus Fusarium solani in the roots of guava plants leads to the development of root galls, causing significant damage. In contrast, the species P. guineense and P. cattleianum have been identified as resistant and immune to the nematode, respectively. In this study, the researchers aimed to compare the metabolomic profiles of infected and uninfected roots of P. guajava, P. cattleianum, and P. guineense using mass spectrometry coupled with liquid chromatography (LC-MS). The goal was to identify secondary metabolites that could potentially be utilized as biochemical resources for nematode control. The findings of the study demonstrated that the plant metabolism of all three species undergoes alterations in response to the phytopathogen inoculation. By employing molecular networks, the researchers identified that the secondary metabolites affected by the infection, whether produced or suppressed, are primarily of a polar chemical nature. Further analysis of the database confirmed the polar nature of the regulated substances after infection, specifically hydrolysable tannins and lignans in P. guineense and P. cattleianum. Interestingly, a group of non-polar substances belonging to the terpene class was also identified in the resistant and immune species. This suggests that these terpenes may act as inhibitors of M. enterolobii, working as repellents or as molecules that can reduce oxidative stress during the infection process, thus enhancing the guava resistance to the nematode. Overall, this study provides valuable insights into the metabolic alterations occurring in different Psidium spp. in response to M. enterolobii infection. The identification of specific secondary metabolites, particularly terpenes, opens up new possibilities for developing effective strategies to control the nematode and enhance guava resistance

Antimicrobial and antioxidant activity of kaempferol rhamnoside derivatives from Bryophyllum pinnatum

Abstract Background Bryophyllum pinnatum (Lank.) Oken (Crassulaceae) is a perennial succulent herb widely used in traditional medicine to treat many ailments. Its wide range of uses in folk medicine justifies its being called "life plant" or "resurrection plant", prompting researchers' interest. We describe here the isolation and structure elucidation of antimicrobial and/or antioxidant components from the EtOAc extract of B. pinnatum. Results The methanol extract displayed both antimicrobial activities with minimum inhibitory concentration (MIC) values ranging from 32 to 512 μg/ml and antioxidant property with an IC50 value of 52.48 μg/ml. Its partition enhanced the antimicrobial activity in EtOAc extract (MIC = 16-128 μg/ml) and reduced it in hexane extract (MIC = 256-1024 μg/ml). In addition, this process reduced the antioxidant activity in EtOAc and hexane extracts with IC50 values of 78.11 and 90.04 μg/ml respectively. Fractionation of EtOAc extract gave seven kaempferol rhamnosides, including; kaempferitrin (1), kaempferol 3-O-α-L-(2-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (2), kaempferol 3-O-α-L-(3-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (3), kaempferol 3-O-α-L-(4-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (4), kaempferol 3-O-α-D- glucopyranoside-7-O-α-L-rhamnopyranoside (5), afzelin (6) and α-rhamnoisorobin (7). All these compounds, except 6 were isolated from this plant for the first time. Compound 7 was the most active, with MIC values ranging from 1 to 2 μg/ml and its antioxidant activity (IC50 = 0.71 μg/ml) was higher than that of the reference drug (IC50 = 0.96 μg/ml). Conclusion These findings demonstrate that Bryophyllum pinnatum and some of its isolated compounds have interesting antimicrobial and antioxidant properties, and therefore confirming the traditional use of B. pinnatum in the treatment of infectious and free radical damages.</p

Reactive Oxygen Species Production and Mitochondrial Dysfunction Contribute to Quercetin Induced Death in Leishmania amazonensis

BACKGROUND: Leishmaniasis, a parasitic disease caused by protozoa of the genus Leishmania, affects more than 12 million people worldwide. Quercetin has generated considerable interest as a pharmaceutical compound with a wide range of therapeutic activities. One such activity is exhibited against the bloodstream parasite Trypanosoma brucei and amastigotes of Leishmania donovani. However, the mechanism of protozoan action of quercetin has not been studied. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we report here the mechanism for the antileishmanial activity of quercetin against Leishmania amazonensis promastigotes. Quercetin inhibited L. amazonensis promastigote growth in a dose- and time- dependent manner beginning at 48 hours of treatment and with maximum growth inhibition observed at 96 hours. The IC(50) for quercetin at 48 hours was 31.4 µM. Quercetin increased ROS generation in a dose-dependent manner after 48 hours of treatment. The antioxidant GSH and NAC each significantly reduced quercetin-induced cell death. In addition, quercetin caused mitochondrial dysfunction due to collapse of mitochondrial membrane potential. CONCLUSIONS/SIGNIFICANCE: The effects of several drugs that interfere directly with mitochondrial physiology in parasites such as Leishmania have been described. The unique mitochondrial features of Leishmania make this organelle an ideal drug target while minimizing toxicity. Quercetin has been described as a pro-oxidant, generating ROS which are responsible for cell death in some cancer cells. Mitochondrial membrane potential loss can be brought about by ROS added directly in vitro or induced by chemical agents. Taken together, our results demonstrate that quercetin eventually exerts its antileishmanial effect on L. amazonensis promastigotes due to the generation of ROS and disrupted parasite mitochondrial function

Efecto de TBT en Acetilcolinesterasa de Perna Perna (Linnaeus, 1758) (Mytilidae)

La acetilcolineterasa (AChE) es uno de los biomarcadores más conocidos en los programas de monitoreo ecotoxicológico de los organofosforados y carbamatos. Sin embargo, algunos estudios plantean la posibilidad de que la acetilcolinesterasa también actúe como un biomarcador para otros xenobióticos. Con este enfoque hemos realizado pruebas de comparación de este biomarcador en dos ubicaciones en la ciudad de Arraial do Cabo � RJ, Brasil. La playa dos Anjos, una ensenada que alberga un puerto considerado como un entorno impactado por tributilestaño y una playa oceánica Praia Grande que se introdujo en nuestro estudio como un entorno de referencia. En dos muestras (03/04/2004 y 09/06/2005) las actividades específicas de la actividad de la acetilcolinesterasa en branquias de P perna fueron mayores en la playa dos Anjos, corroborando los experimentos de laboratorio realizados por otros autores. Estudios adicionales son importantes para la determinación del imposex asociado a la acetilcolinesterasa, y también puede integrar la función de los biomarcadores de exposición a tributilestaño en los moluscos.La acetilcolineterasa (AChE) es uno de los biomarcadores más conocidos en los programas de monitoreo ecotoxicológico de los organofosforados y carbamatos. Sin embargo, algunos estudios plantean la posibilidad de que la acetilcolinesterasa también actúe como un biomarcador para otros xenobióticos. Con este enfoque hemos realizado pruebas de comparación de este biomarcador en dos ubicaciones en la ciudad de Arraial do Cabo � RJ, Brasil. La playa dos Anjos, una ensenada que alberga un puerto considerado como un entorno impactado por tributilestaño y una playa oceánica Praia Grande que se introdujo en nuestro estudio como un entorno de referencia. En dos muestras (03/04/2004 y 09/06/2005) las actividades específicas de la actividad de la acetilcolinesterasa en branquias de P perna fueron mayores en la playa dos Anjos, corroborando los experimentos de laboratorio realizados por otros autores. Estudios adicionales son importantes para la determinación del imposex asociado a la acetilcolinesterasa, y también puede integrar la función de los biomarcadores de exposición a tributilestaño en los moluscos