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α-Amyrenone and β-amyrenone are triterpenoid isomers that occur naturally in very low concentrations in several oleoresins from Brazilian Amazon species of Protium (Burseraceae). This mixture can also be synthesized by oxidation of α,β-amyrins, obtained as major compounds from the same oleoresins. Using a very simple, high yield procedure, and using a readily commercially available mixture of α,β-amyrins as substrate, the binary compound α,β-amyrenone was synthesized and submitted to physico-chemical characterization using different techniques such as high-performance liquid chromatography, nuclear magnetic resonance (1H and 13C), mass spectrometry, scanning electron microscopy, differential scanning calorimetry, thermogravimetry and derivative thermogravimetry, and Fourier transform infrared spectroscopy (FTIR). Biological effects were also evaluated by studying the inhibition of enzymes involved in the carbohydrate and lipid absorption process, such as α-amylase, α-glucosidase, lipase, and their inhibitory concentration values of 50% of activity (IC50) were also determined. α,β-Amyrenone significantly inhibited α-glucosidase (96.5% ± 0.52%) at a concentration of 1.6 g/mL. α,β-Amyrenone, at a concentration of 100 µg/mL, showed an inhibition rate on lipase with an IC50 value of 82.99% ± 1.51%. The substances have thus shown in vitro inhibitory effects on the enzymes lipase, α-glucosidase, and α-amylase. These findings demonstrate the potential of α,β-amyrenone for the development of drugs in the treatment of chronic metabolic diseases. [ABSTRACT FROM AUTHOR]

The article presents a study which aims to investigate the putative anxiolytic effect of acute administration of copaiba oil oleoresin extracted from Copaifera reticulata Ducke (CRD). The study administered the CRD on male Wistar rats submitted to an elevated model of anxiety using an ethopharmacological analysis. It revealed that the acute treatment of rats with anxiety disorders with CRD copaiba oil has produced a dose-dependent anxiolytic effect.

Abstract Purpose  To evaluate the pharmacological activity of insulin-loaded alginate/chitosan nanoparticles following oral dosage in diabetic rats. Methods  Nanoparticles were prepared by ionotropic pre-gelation of an alginate core followed by chitosan polyelectrolyte complexation. In vivo activity was evaluated by measuring the decrease in blood glucose concentrations in streptozotocin induced, diabetic rats after oral administration and flourescein (FITC)-labelled insulin tracked by confocal microscopy. Results  Nanoparticles were negatively charged and had a mean size of 750 nm, suitable for uptake within the gastrointestinal tract due to their nanosize range and mucoadhesive properties. The insulin association efficiency was over 70% and insulin was released in a pH-dependent manner under simulated gastrointestinal conditions. Orally delivered nanoparticles lowered basal serum glucose levels by more than 40% with 50 and 100 IU/kg doses sustaining hypoglycemia for over 18 h. Pharmacological availability was 6.8 and 3.4% for the 50 and 100 IU/kg doses respectively, a significant increase over 1.6%, determined for oral insulin alone in solution and over other related studies at the same dose levels. Confocal microscopic examinations of FITC-labelled insulin nanoparticles showed clear adhesion to rat intestinal epithelium, and internalization of insulin within the intestinal mucosa. Conclusion  The results indicate that the encapsulation of insulin into mucoadhesive nanoparticles was a key factor in the improvement of its oral absorption and oral bioactivity. [ABSTRACT FROM AUTHOR]

Copaiba oil resin (COR) obtained from Copaifera multijuga Hayne has been used in popular medicine as an antinflammatory and for the treatment of bronchitis, ulcers and cancer. The aim of this study was to evaluate the action of COR and its fractions on the inhibition of lung metastasis and tumour growth induced by B16F10 melanoma cells in mice and cytotoxicity in vitro using Trypan Blue exclusion method and MTT conversion. Mice which have received subcutaneously B16F10 cells developed a solid tumour that reached a peak at 17 days. Together with the increase in tumour growth we also observed an increase in the number of lung nodules. There was a positive correlation between the in vitro cytotoxic assay and in vivo antitumour activity. The oral administration of COR (at 2 g/Kg in the days 3, 5, 7, 10, 12 and 14 after inoculation of tumoral cells) reduced tumour growth by 58% and tumour weight by 76%. At the same dose COR reduced the number of lung nodules by 47.1%. In vitro experiments showed that COR incubated with the melanoma cell line reduced cell viability in a concentration and time-dependent manner. Diterpenic and sesquiterpenic fractions or reconstituted oil induced cytotoxicity. Our results shows that COR and its fractions have tumouricidal activity in the melanoma cell line in both models in vivo and in vitro. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Franz cells permeation assay has been performed for over 25 years. However, the advent of nanotechnology created a whole new world, especially with regard to topical products. In this new global scenario an increasing number of nanostructure-based delivery systems (NDSs) have emerged and a global warning relating to the safety of these NDSs is arising. This work studied the efficacy of the Franz cells assay, comparing it with the radiolabeling biodistribution test. For this purpose a formulation of sunscreen based on an NDS was developed and characterized. The results demonstrated both that the NDS did not present in vitro cytotoxicity and that the radiolabeling biodistribution test is more precise for the evaluation of NDS cosmetics than the Franz cells assay, since it detected the permeation of the NDS at a picogram order. Due to this fact, and considering all the concerns related to NDSs and nanoparticles in general, more precise methods must be used in order to guarantee the safe use of these new classes of products. [ABSTRACT FROM AUTHOR]