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Própolis: atualizações sobre a química e a farmacologia

Propolis (bee glue) is a complex mixture, formed by resinous and balsamic material. Its chemical composition is variable and complex, being related with the flora of each region visited by the bees and with the period of resins collection. Flavonoids, aromatic acids, terpenoids and phenylpropanoids, fatty acids, and other compounds are found in propolis. In the last 30 years, propolis has become subject of intense pharmacological and chemical studies. In different parts of the world it is indicated to improve health and prevent illnesses. Currently, it is available in some pharmaceutical forms as capsules, extracts, mouthrinses, powder form, among others. Indeed, studies correlating the chemical composition with the biological activity are necessary, defining each type of propolis with its therapeutic application. It is an essential task for a market ever bigger and demanding in the whole word.

Variabilidade sazonal dos constituintes da própolis vermelha e bioatividade em Artermia salina

Propolis is a resinous hive product collected by honeybees from plant sources. The composition of the propolis depends on the season, the vegetation, and the area of collection. It presents a diverse biological activities such as antimicrobial, antioxidant and antitumoral. The seasonal variability of the red propolis constituents from Pernambuco State were accomplished in the months of February, June and October of 2006. The volatile red propolis constituients were captured by the dynamic headspace technique and analyzed by GC-MS. In the analysis of the samples, 34 constituents were identified as the mono and sesquiterpens, phenylpropanoids, aldehydes, cetons and n-alcanes, presenting as majority constituents the trans-anethol, α-copaene and methyl cis-isoeugenol. The phytochemistry profile was performed by thin layer chromatography (TLC). Through this technique the majority constituents were identified as phenols. The Brine shrimp bioassay was used to evaluate of the red propolis methanolic extract, which demonstrated a DL50 of 18.9 µg/mL and an activity antitumoral was possibly suggested.

Chitosan Hydrogel in combination with Nerolidol for healing wounds.

Chitosan is a natural polymer with antibacterial property, that is biodegradable, extremely abundant and non-toxic. This study aimed to develop and characterize chitosan hydrogels in combination with nerolidol, in order to optimize the antimicrobial and healing properties. The hydrogels were prepared using a reaction of the chitosan with acetic acid solution, followed by the addition of 2 or 4% of the nerolidol. Using thermogravimetry, differential scanning calorimetry and infrared spectroscopy, the incorporation of nerolidol in the hydrogel was confirmed. Direct contact tests using hydrogels and Staphylococcus aureus showed a synergistic effect in the materials, enabling total inhibition of bacterial growth. The hydrogel containing 2% nerolidol showed excellent healing effects. The beginning of re-epithelialization and reorganization of collagen was already observed on the 7th day of treatment. The material created proofed to be promising as a healing and antibacterial agent.

Biopolymers and pilocarpine interaction study for use in drug delivery systems (DDS)

This work aimed at the investigation of pilocarpine’s interaction in the association of cashew gum (CG) and chitosan (CH) biopolymers because of mucoadhesive and prolonged release properties of this polymeric system. To elucidate this issue, characterization techniques, such as DSC, TG, XRD, IR, were applied besides DFT B3LYP/6-31++G(d,p) computational calculations. According to this approach, CG interacts with pilocarpine having a protective thermal effect on the drug and CH can reduce its thermal stability. These interactions occur, preferably, between a carbonyl group from pilocarpine and hydroxyl groups from biopolymers in which hydrogen bonds are involved. Thus, this work was able to identify interactions between the drug and the biopolymers and how, in a molecular approach, they occur. These results allow for the full understanding of the influence of each biopolymer for future pilocarpine-release systems.

Preparation and physicochemical characterization of binary composites palygorskite–chitosan for drug delivery

This work aimed the evaluation of pH influence in the obtainment of composites from palygorskite (PAL) and chitosan (CS). The materials PAL/CS-1 and PAL/CS-2 were obtained by similar methodology with modified pHs: 5.0xa0±xa00.5 and 11.0xa0±xa00.5, respectively. Both materials were evaluated for specific surface area analysis, elemental analysis, XRD, FTIR, thermal analysis, MEV and interaction drug composite, using 5-aminosalicylic acid (5-ASA) as model. The surface area analysis data showed the reduction in PAL/CS-2 related to CS presence on surface in contrast with PAL/CS-1, which corroborate with elemental analysis present nine times more of CS in PAL/CS-2 composition. Regarding to XRD data, the interaction of CS with PAL did not cause modification in clay structure in PAL/CS-2. These results were confirmed by FTIR data with the N–H deformation vibration in PAL/CS-2 while PAL/CS-1 was invariable to PAL. In thermal analysis, results were observed 60.2% residual mass to PAL/CS-2, which it was lower than PAL (87.2%) and PAL/CS-1 (86.7%), due to CS decomposition which had enthalpy energy of 62.1xa0Jxa0g−1xa0K−1, confirming the data previously cited. PAL/CS-2 presented 5-ASA adsorption of 7.9xa0mgxa0g−1, which was inferior to others probably caused by scarcity of active sites of PAL already occupied by CS. These results showed that pH control was fundamental to enhance efficiency of obtainment of composite in basic pH because the decrease in CS protonation degree increasing interaction between this one and PAL, although it contributed to decrease in 5-ASA adsorption due to low availability of interaction sites.

In vitro bioactivity and cytotoxicity of films based on mesocarp of Orbignya sp. and carboxymethylcellulose as a tannic acid release matrix

This study aims to obtain mesocarp films of Orbignya sp. (MB) and carboxymethylcellulose (CMC) for application as a drug release matrix. Tannic acid (TA) was used as a standard drug. The films were evaluated by infrared, swelling power, TA release profile, bioactivity and in vitro cytotoxicity. Infrared results indicated absorption at 1.205u2009cm-1, which is characteristic of ester group from the incorporated tannin. The MB-CMC film had 449.15% swelling power, release of 71.01% of TA of the matrix after 24u2009h. Films showed scavenger activity of radicals DPPH (79.07u2009±u20091.71% to 82.17u2009±u20091.94%) and ABTS+ (82.20u2009±u20090.30% to 88.90u2009±u20091.05). The MB-CMC film also showed in vitro cytotoxicity on sarcoma-180 (91.86u2009±u20099.97%) and on promastigote forms of Leishmania major (100%). Polymers showed good compatibility in the mixture and the results suggest the films obtained are promising as drug release matrices.

Obtaining the palygorskite:chitosan composite for modified release of 5-aminosalicylic acid

This studys aim was to obtain composites from palygorskite (PLG) and chitosan (CS) in order to modify 5-aminosalicylic (5-ASA) release. Initially, the PLG:CS composite was obtained using glutaraldehyde (GLA) as a reticular agent. Then, PLG, CS and PLG:CS were characterized by means of analytical techniques such as CHN elemental analysis, surface area analysis, XRD, FTIR, DSC and TG, SEM, adsorption tests and release profiles. Based on analytical data, the formation of the PLG:CS composite which showed the presence about 19% of CS, decrease in specific surface area, morphological analysis modified, visible change of crystallinity, of FTIR and thermal analysis. In relation to the drug-composite interaction, PLG:CS exhibited a significant increase in adsorption with 5-ASA at 58.24% in relation to PLG and CS which were at 16.29% and 23.96% respectively. The release profiles show that the PLG:CS composite changed the 5-ASA release speed in analyzed simulated fluids (intestinal and stomach) unlike other systems. Thus, the PLG:CS composite with proven synergy of the PLG and CS inherent properties showing 5-ASA effective modified release. Hence, this composite has potential benefits for the vectorization of drugs.

Use of phyllosilicate clay mineral to increase solubility olanzapine

Phyllosilicates have interesting properties, such as high capacity of ion exchange, adsorption, physicochemical stability and low/null toxicity, and thus, they are a promising material in pharmaceutical studies. Olanzapine (OLZ), used in the treatment of schizophrenia, is a drug of high cost and low water solubility, which are an obstacle to its use. In this work, an oral delivery system was developed using phyllosilicate (PHY-NT) and OLZ together to increase its solubility. PHY-NT was synthesized by sol–gel method, and then, OLZ was adsorbed creating the system called PHY-NT:OLZ. Thermal analysis was performed to investigate possible interactions between olanzapine and phyllosilicate. a sharp endothermic peak at 468xa0K was observed, which corresponds to the melting process of OLZ. When OLZ was added to PHY-NT, this peak was absent, suggesting an efficient denaturation of its crystal lattice. FTIR spectroscopy and X-ray powder diffraction were performed as complementary techniques to adequately support thermal analysis results. The created system caused a considerable increase in OLZ dissolution efficiency, and more than 80xa0% of the drug was released from PHY-NT:OLZ after 20xa0min. Drug release was evaluated in vitro and showed a Fickian diffusion-based pattern. Thus, results suggest that PHY-NT can be used as an alternative to increase drug dissolution rate of OLZ, expanding applications of these materials.

Methyl-β-cyclodextrin Inclusion Complex with β-Caryophyllene: Preparation, Characterization, and Improvement of Pharmacological Activities

β-Caryophyllene (BCP) is a sesquiterpene that shows high potential in pharmacological applications. However, these have been drastically limited by the respective volatility and poor water solubility. The present study investigates the formation of inclusion complexes between BCP and methyl-β-cyclodextrin (MβCD) and shows that these complexes promote a significant improvement of the anti-inflammatory, gastric protection, and antioxidant activities relative to neat BCP. It is shown that the solubility of BCP is significantly increased through complexation in phase solubility studies. Inclusion complexes with MβCD in solid state were prepared by three different methods, kneading, rotary evaporation, and lyophilization, with the latter confirmed by differential scanning calorimetry, Fourier transformed infrared spectroscopy, scanning electron microscopy, 1H NMR spectroscopy, and molecular dynamics studies. This study provides for the first time a full characterization of inclusion complexes between BCP and MβCD and highlights the impact of complex formation upon pharmacological activity.

Hydroxyapatites Obtained from Different Routes and their Antimicrobial Properties

Among applications of ceramics in technological context, hydroxyapatite (HAp) stands out in the scientific community due to chemical biocompatibility and molecular similarity with the structures of bone and dental tissues. Such features are in addition to its antimicrobial properties. This work aimed firstly to synthesize hydroxyapatite by two different routes: hydrothermal (HD HAp) and co-precipitation (CP HAp), and secondly to verify the antimicrobial properties of these materials through direct contact tests against Staphylococcus aureus (SA10) and Escherichia coli (EC7) bacteria. These materials were characterized by XRD, Raman, and TEM. Antimicrobial tests showed inhibitory efficacy of 97.0% and 9.5% of CP HAp for SA10 and EC7, respectively. The HD HAp showed inhibitory effect of 95.0% and 0.0% for SA10 and EC7, respectively. The inhibitory effect of the tested materials against Staphylococcus aureus may be related to the HAp hydrophilicity.