Prenylated flavonoid-enriched fraction from Maclura tinctoria shows biological activity against Staphylococcus aureus and protects Galleria mellonella larvae from bacterial infection.

BACKGROUND: The Atlantic Forest biome extends along the entire Brazilian coast and is home to approximately 20,000 plant species, many of which are endemic; it is considered one of the hotspot regions of the planet. Several of these species are sources of natural products with biological activities that are still unknown. In this study, we evaluated the antimicrobial activity of 90 extracts derived from native Atlantic Forest tree species against Staphylococcus aureus, an important human and veterinary pathogen. METHODS: Extracts from native Atlantic Forest tree species were evaluated for their antimicrobial activity against S. aureus by in vitro standard methods. Phytochemical fractionation of the extract from Maclura tinctoria was performed by liquid-liquid partitioning. LC-DAD-ESI-MS was used for identification of constituents in the most active fraction. Damage of cells and alterations in the permeability of cell membrane were determined by atomic force microscopy (AFM) and crystal violet uptake assay, respectively. In vivo antimicrobial activity was evaluated using Galleria mellonella larvae infected with S. aureus with survival data collected using the Kaplan-Meier method. RESULTS: Among the organic or aqueous extracts tested here, 26 showed biological activity. Eight species showed relevant results, with a minimum inhibitory concentration (MIC) below 1 mg/mL. Antibacterial activity was registered for three species for the first time. An organic extract from Maclura tinctoria leaves showed the lowest MIC (0.08 mg/mL). Fractionation of this extract by liquid-liquid partitioning led to obtaining fraction 11FO d with a MIC of 0.04 mg/mL. This fraction showed strong activity against veterinary S. aureus isolates and contributed to the increased survival of Galleria mellonella larvae infected with S. aureus ATCC 29213. The bacterial surface was not altered by the presence of 11FO d, and no cell membrane damage was detected. The LC-DAD-ESI/MS analyses identified prenylated flavonoids as the major constituents responsible for the antibacterial activity of this active extract. CONCLUSION: A fraction enriched in prenylated isoflavones and flavanones from M. tinctoria showed in vitro and in vivo efficacy as antistaphylococcal agents. These findings justify the need for further research to elucidate the mechanisms of action of these compounds.

Croton urucurana Baillon stem bark ointment accelerates the closure of cutaneous wounds in knockout IL-10 mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Croton urucurana Baill. (Euphorbiaceae) is a plant used in Brazilian popular medicine for the treatment of wound healing, inflammatory diseases, gastritis, infections, and hemorrhoids. AIM: The present study aimed to evaluate the in vivo wound healing activity of an ointment based on ethanolic extract of C. urucurana stem bark, at concentrations of 5% and 10%, and to relate it with compounds that could be associated with this activity. MATERIALS AND METHODS: Analyses by FIA-ESI-IT-MSn were carried out to investigate the chemical composition of C. urucurana. Knockout IL-10 (n = 60) mice and wild type C57 (n = 12) mice were separated into 6 groups to evaluate the wound healing activity. Knockout IL-10 mice: SAL (0.9% saline); BAS (ointment base); SS (1% silver sulfadiazine); CR1 (ointment with extract of C. urucurana 5%); CR2 (ointment with extract of C. urucurana 10%); and wild mice C57: SALC57 (Saline 0.9%). A circular wound with 10 mm in diameter was generated on the dorsal of the animals. Tissue specimen of the wounds were removed on days 7 and 14 of the treatment for histopathological, oxidative status and analyses of pro-and anti-inflammatory cytokines in scar tissue. RESULTS: In the phytochemical profile, twelve proanthocyanidins were identified (in the form of monomers, dimers, trimers, and tetramers), based on (epi)catechin and (epi)gallocatechin. Furthermore, two quercetin derivatives and two alkaloids were detected. The groups treated with CR1 and CR2 ointments presented higher rate of wound closure, increased total number of cells, mast cells, blood vessels and higher deposition of type III and I collagen. In addition, they showed increased amount of pro-inflammatory cytokines (IL- 2 and IFN-γ), and anti-inflmatory cytokines (IL-4), on the 7th day of treatment. CONCLUSION: The results presented support the popular use of preparations based on the bark of C. urucurana as a healing compound.

CHEMICAL COMPOSITION, CHARACTERIZATION OF ANTHOCYANINS AND ANTIOXIDANT POTENTIAL OF EUTERPE EDULIS FRUITS: APPLICABILITY ON GENETIC DYSLIPIDEMIA AND HEPATIC STEATOSIS IN MICE.

UNLABELLED: The significance of polyphenol intake for the prevention of chronic diseases is controversial. OBJECTIVE: this study investigated the chemical composition and antioxidant potential of an anthocyanin-rich extract from Euterpe edulis fruits (LPEF) and its effects on liver steatosis in dyslipidemic apoE-/- knockout mice. MATERIALS AND METHODS: mice were divided into G1 (C57BL/6) standard diet; G2 (apoE-/-) standard diet, G3 (apoE-/-) 2% LPEF, G4 (apoE-/-) 6% LPEF, G5 (apoE-/-) 10% LPEF, G6 (apoE-/-) 2% α-tocopherol acetate. After 75 days of treatment, the animals were euthanized. The LPEF contained a high level of monomeric anthocyanins (301.4 mg/100g) and marked antioxidant activity. RESULTS: Catalase activity was reduced in G3, G4, G5 and G6 compared to G2. Superoxide dismutase was reduced only in G4. The animals in G4, G5, and G6 showed low HDL and triglycerides levels compared to G2. The proportion of lipid droplets in liver tissue was reduced in G4 and G5 compared to G2, G3, and G6. CONCLUSION: The results indicated that E. edulis pulp is rich in anthocyanins and the LPEF dietary consumption can reduce the severity of liver steatosis in apoE-/- mice, an effect that is potentially mediated by the antioxidant activity of this extract and modulation of triglyceride serum levels.

El papel de los polifenoles en la prevención de enfermedades crónicas es controvertido. Objetivo: este estudio investigó la composición química y el potencial antioxidante de un extracto del fruto de Euterpe edulis rico en antocianinas (LPEF) y sus efectos en la esteatosis hepática en ratones apoE-/- knockout con dislipidemia. Material y métodos: los ratones fueron divididos en los siguientes grupos; G1 (C57BL/6) con una dieta estándar; G2 (apoE-/-) con dieta estándar; G3 G3 (apoE-/-) con 2% de LPEF; G4 (apoE-/-) con 6% de LPEF; G5 (apoE-/-) con 10% de LPEF y G6 (apoE-/-) con 2% acetato α-tocoferol (α-tocopherol acetate). Después de 75 días de tratamiento, los animales fueron eutanizados. El LPEF contenía un alto nivel de antocianinas monoméricas (301,4 mg/100 g) con notable actividad antioxidante. Resultados: la actividad catalasa fue reducida en los grupos G3, G4, G5 y G6 comparada con G2. La superoxidasa dismutasa solo se redujo en el grupo G4. Los animales de G4, G5 y G6 mostraron bajos niveles de HDL triglicéridos, comparados con G2. La proporción de lípidos en el tejido hepático fue reducida en G4 y G5, comparado con G2, G3 y G6. Conclusión: los resultados indicaron que la pulpa de E. edulis es rica en antocianinas, y que el consumo de LPEF en la dieta puede reducir la severidad de la esteatosis hepática en ratones apoE-/-, un efecto que es potencialmente mediado por la actividad antioxidante de este extracto y la modulación en los niveles séricos de triglicéridos.

Efeitos biológicos das antocianinas no processo aterosclerótico / Biological effects of anthocyanins on the atherosclerotic process

As antocianinas são metabólitos secundários biossintetizados por plantas e pertencentes ao grupo dos flavonóides. Pesquisas indicam que as antocianinas podem aumentar a resistência da LDL à oxidação, comparado a outros compostos com alto poder antioxidante, como o ácido L-ascórbico, e reduzir fatores pró-inflamatórios, como citocinas, quimiocinas, moléculas de adesão e metaloproteinases. Como a inflamação e a oxidação são processos característicos da aterosclerose, tem se investigado o efeito das antocianinas no processo aterosclerótico e há evidências que estes compostos podem diminuir o desenvolvimento e a progressão das lesões ateroscleróticas.

Anthocyanins are secondary metabolites biosynthesized by plants and belonging to the group of flavonoids. Research indicates that anthocyanins can increase resistance of LDL to oxidation, compared to other compounds with high antioxidant properties, such as L-ascorbic acid, and reduce pro-inflammatory factors such as cytokines, chemokines, adhesion molecules and metalloproteinases. As inflammation and oxidation processes are characteristic of atherosclerosis, has investigated the effect of anthocyanins in the atherosclerotic process and there is evidence that these compounds can reduce the development and progression of atherosclerotic lesions.