Chrysin-Loaded Microemulsion: Formulation Design, Evaluation and Antihyperalgesic Activity in Mice

Chrysin is a bioactive flavonoid found in pollens, passion flowers, honey, royal jelly, and propolis, which is commonly used as an ingredient in natural food supplements and is primarily re-sponsible for their pharmacological properties. A transparent chrysin-loaded microemulsion (CS-ME) prepared through a ternary phase diagram was evaluated for use as an antihyperalgesic formulation. It was formulated with 40% Labrasol\uae (surfactant), 5% isopropyl myristate (oil phase) and 55% water (aqueous phase) and classified as an oil-in-water (O/W) microsized system (74.4 \ub1 15.8 nm). Its negative Zeta potential ( 1216.1 \ub1 1.9 mV) was confirmed by polarized light microscopy and dynamic light scattering analysis. In vitro studies in Franz-type static diffusion cells showed that chrysin release from CS-ME followed zero-order kinetics. Oral administration of CS-ME in mice resulted in a statistically significantly reduction (p < 0.05) in carrageenan-induced mechanical hyperalgesia compared to the control group. Treatment with CS-ME also showed anti-inflammatory activity by significantly decreasing the TNF-\u3b1 level (p < 0.01) and increasing that of IL-10 (p < 0.05) compared to the control group. These results suggest that the proposed microsystem is a promising vector for the release of chrysin, being able to improve its capacity to modulate inflammatory and nociceptive responses

Effect of seasonality on chemical profile and antifungal activity of essential oil isolated from leaves Psidium salutare (Kunth) O. Berg

Medicinal plants play a crucial role in the search for components that are capable of neutralizing the multiple mechanisms of fungal resistance. Psidium salutare (Kunth) O. Berg is a plant native to Brazil used as both food and traditional medicine to treat diseases and symptoms such as stomach ache and diarrhea, whose symptoms could be related to fungal infections from the genus Candida. The objective of this study was to investigate the influence of seasonal variability on the chemical composition of the Psidium salutare essential oil, its antifungal potential and its effect on the Candida albicans morphogenesis. The essential oils were collected in three different seasonal collection periods and isolated by the hydrodistillation process in a modified Clevenger apparatus with identification of the chemical composition determined by gas chromatography coupled to mass spectrometry (GC/MS). The antifungal assays were performed against Candida strains through the broth microdilution method to determine the minimum fungicidal concentration (MFC). Fungal growth was assessed by optical density reading and the Candida albicans dimorphic effect was evaluated by optical microscopy in microculture chambers. The chemical profile of the essential oils identified 40 substances in the different collection periods with γ-terpinene being the predominant constituent. The antifungal activity revealed an action against the C. albicans, C. krusei and C. tropicalis strains with an IC50 ranging from 345.5 to 2,754.2 µg/mL and a MFC higher than 1,024 µg/mL. When combined with essential oils at sub-inhibitory concentrations (MIC/16), fluconazole had its potentiated effect, i.e. a synergistic effect was observed in the combination of fluconazole with P.salutare oil against all Candida strains; however, for C. albicans, its effect was reinforced by the natural product in all the collection periods. The results show that the Psidium salutare oil affected the dimorphic transition capacity, significantly reducing the formation of hyphae and pseudohyphae in increasing concentrations. The results show that P. salutare oil exhibits a significant antifungal activity against three Candida species and that it can act in synergy with fluconazole. These results support the notion that this plant may have a potential use in pharmaceutical and preservative products

Nanoencapsulated α-terpineol attenuates neuropathic pain induced by chemotherapy through calcium channel modulation

Although chemotherapy-induced peripheral neuropathy is one of the main medical complaints of cancer patients, there are currently no specific drugs for the effective treatment. In this respect, α-terpineol (TP) seems to be a potential candidate for this purpose, since it has several pharmacological properties that can be improved by nanosytems. Therefore, the objective of this study was to develop and investigate an antinociceptive action of TP in nanocapsules (TP-LNC) on a peripheral neuropathy induced by paclitaxel (PTX) in mice. Nanocapsules were obtained through the interfacial deposition of preformed polymer method and physicochemically characterized. The effect of TP and TP-LNC was assessed using the hyperalgesia test in mice with neuropathy induced by PTX (32 mg/kg, i.p.). Its effect on calcium channels was evaluated by patch-clamp and molecular docking. TP-LNC presented satisfactory stability and encapsulation efficiency of 64.5%; it also prolonged the antihyperalgesic effect when cooperated with free TP. Moreover, it was found that TP presented molecular interactions with different channels for calcium, being able to reduce calcium currents. These findings bring new evidence about the analgesic action of TP and its modulating action of calcium channels and reiterate the benefits of the encapsulation of monoterpenes in nanosystems

Modulation of antibiotic activity by the hydroalcoholic extract from leaves of <i>Caryocar coriaceum</i> WITTM

<p>The aim of this study was to identify the presence of tannins, phenols and flavonoids on the hydroalcoholic extract of <i>Caryocar coriaceum</i> leaves (HECCL) and to determine the antioxidant and antibacterial activity of this extract. The extract was tested alone (1024–1 μg/mL) or associated (MIC/8) with several antibiotics in order to identify any antibacterial activity against multiresistant bacterial strains (<i>Escherichia coli</i>, <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>). The existence of tannins, total phenols (901.31 mg/g) and flavonoids (89.68 mg/g) was confirmed in the HECCL. The presence of rutin and quercetin were confirmed by Thin-layer chromatography (TLC). Using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, the antioxidant activity of the extract (9 μg/mL) was determined. Moreover, the Minimum Inhibitory Concentration (MIC) value found for HECCL was 1024 μg/mL and the association between HECCL (MIC/8) with benzylpenicillin significantly changed its minimum inhibitory concentration from 2500 to 625 μg/mL against <i>E. coli</i>.</p

Nootkatone Inhibits Acute and Chronic Inflammatory Responses in Mice

Nootkatone (NTK) is a sesquiterpenoid found in essential oils of many species of Citrus (Rutaceae). Considering previous reports demonstrating that NTK inhibited inflammatory signaling pathways, this study aimed to investigate the effects of this compound in mice models of acute and chronic inflammation. Murine models of paw edema induced by carrageenan, dextran, histamine, and arachidonic acid, as well as carrageenan-induced peritonitis and pleurisy, were used to evaluate the effects of NTK on acute inflammation. A murine model of granuloma induced by cotton pellets was used to access the impact of NTK treatment on chronic inflammation. In the acute inflammation models, NTK demonstrated antiedematogenic effects and inhibited leukocyte recruitment, which was associated with decreased vascular permeability, inhibition of myeloperoxidase (MPO), interleukin (IL)1-\u3b2, and tumor necrosis factor (TNF)-\u3b1 production. In silico analysis suggest that NTZ anti-inflammatory effects may also occur due to inhibition of cyclooxygenase (COX)-2 activity and antagonism of the histamine receptor type 1 (H1). These mechanisms might have contributed to the reduction of granuloma weight and protein concentration in the homogenates, observed in the chronic inflammation model. In conclusion, NTK exerted anti-inflammatory effects that are associated with inhibition of IL1-\u3b2 and TNF-\u3b1 production, possibly due to inhibition of COX-2 activity and antagonism of the H1 receptor. However, further studies are required to characterize the effects of this compound on chronic inflammation

Action of cholecalciferol and alpha-tocopherol on Staphylococcus aureus efflux pumps

Submitted by Adagilson Silva ([email protected]) on 2017-06-13T19:43:53Z No. of bitstreams: 1 27298617 2016 tin-act.pdf: 373418 bytes, checksum: 5674ad4d8b062cd367d34169f62a13a0 (MD5)Approved for entry into archive by Adagilson Silva ([email protected]) on 2017-06-13T19:44:14Z (GMT) No. of bitstreams: 1 27298617 2016 tin-act.pdf: 373418 bytes, checksum: 5674ad4d8b062cd367d34169f62a13a0 (MD5)Made available in DSpace on 2017-06-13T19:44:14Z (GMT). No. of bitstreams: 1 27298617 2016 tin-act.pdf: 373418 bytes, checksum: 5674ad4d8b062cd367d34169f62a13a0 (MD5) Previous issue date: 2016Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Federal da Paraíba. Laboratório de Microrganismos Genéticos. João Pessoa, PB, Brasil.Universidade Regional do Cariri. Departamento de Química Biológica. Laboratório de Microbiologia e Biologia Molecular. Crato, CE, Brasil.Universidade Federal de Pernambuco. Laboratório de Bioinformática e Biologia Evolucionária. Departamento de Genética. Recife, PE, Brazil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Microbiologia. Recife, PE, Brasil.Centro Universitário UniLeão Sampaio. Juazeiro do Norte, CE, Brasil.Universidade Federal de Sergipe. Aracaju, SE, Brasil.Alpha-tocopherol is one the most abundant and biologically active isoforms of vitamin E. This compound is a potent antioxidant and one of most studied isoforms of vitamin E. Vitamin D3 (cholecalciferol) is an important nutrient for calcium homeostasis and bone health, that has also been recognized as a potent modulator of the immune response. Methicillin-resistant Staphylococcus aureus (MRSA) is the most important causative agent of both nosocomial and community-acquired infections. The aim of this study was to evaluate the inhibitory effect of alpha-tocopherol and cholecalciferol on both S. aureus and multidrug resistant S. aureus efflux pumps. The RN4220 strain has the plasmid pUL5054 that is the carrier of gene that encodes the macrolide resistance protein (an efflux pump) MsrA; the IS-58 strain possesses the TetK tetracycline efflux protein in its genome and the 1199B strain resists to hydrophilic fluoroquinolones via a NorA-mediated mechanism. The antibacterial activity was evaluated by determining the Minimal Inhibitory Concentration (MIC) and a possible inhibition of efflux pumps was associated to a reduction of the MIC. In this work we observed that in the presence of the treatments there was a decrease in the MIC for the RN4220 and IS-58 strains, suggesting that the substances presented an inhibitory effect on the efflux pumps of these strains. Significant efforts have been done to identify efflux pump inhibitors (EPIs) from natural sources and, therefore, the antibacterial properties of cholecalciferol and alpha-tocopherol might be attributed to a direct effect on the bacterial cell depending on their amphipathic structure