Hypotensive Effects of the Triterpene Oleanolic Acid for Cardiovascular Prevention.

BACKGROUND: Hypertension is a highly prevalent chronic disease worldwide and a major cardiovascular risk factor. Oleanolic acid (3ß-hydroxy-olea-12-en-28-oic acid) is a widely distributed bioactive pentacyclic triterpenoid with diverse biological activities such as anti-inflammatory, hepaprotective, anti-diabetic or anti-hypertensive. OBJECTIVE: The aim of this study was to review and highlight the available data regarding the antihypertensive activity of oleanolic acid and the described mechanisms of action. METHODS: Extensive searches were made in the available literature on oleanolic acid and the data investigating its antihypertensive effects were analysed. RESULTS: Most of the research has been performed on animal models of hypertension, ex vivo studies with aortic ring and some in vitro tests with cell cultures, whereas clinical trials are still lacking. Treatment of hypertensive animals with oleanolic acid significantly ameliorated the rise in the systolic blood pressure. In addition, the hypotensive effects of oleanolic acid are also related to a potent diuretic-natriuretic activity and nephroprotection. In vitro studies have characterized the participation of various signalling pathways that modulate the release of vasodilation mediators. CONCLUSION: In vitro and in vivo studies suggest that oleanolic acid effectively reduces blood pressure and could be an interesting co-adjuvant to conventional treatment of hypertension.

Evaluation of keratin biomaterial containing silver nanoparticles as a potential wound dressing in full-thickness skin wound model in diabetic mice.

Keratin is a cytoskeletal scaffolding protein essential for wound healing and tissue recovery. The aim of the study was to evaluate the potential role of insoluble fur keratin-derived powder containing silver nanoparticles (FKDP-AgNP) in the allogenic full-thickness surgical skin wound model in diabetic mice. The scanning electron microscopy image evidenced that the keratin surface is covered by a single layer of silver nanoparticles. Data obtained from dynamic light scattering and micellar electrokinetic chromatography showed three fractions of silver nanoparticles with an average diameter of 130, 22.5, and 5 nm. Microbiologic results revealed that the designed insoluble FKDP-AgNP dressing to some extent inhibit the growth of Escherichia coli and Staphylococcus aureus. In vitro assays showed that the FKDP-AgNP dressing did not inhibit fibroblast growth or induce hemolysis. In vivo studies using a diabetic mice model confirmed biocompatible properties of the insoluble keratin dressings. FKDP-AgNP significantly accelerated wound closure and epithelization at Days 5 and 8 (p < .05) when compared with controls. Histological examination of the inflammatory response documented that FKDP-AgNP-treated wounds contained predominantly macrophages, whereas their untreated variants showed mixed cell infiltrates rich in neutrophils. Wound inflammatory response based on macrophages favors tissue remodeling and healing. In conclusion, the investigated FKDP-AgNP dressing consisting of an insoluble fraction of keratin, which is biocompatible, significantly accelerated wound healing in a diabetic mouse model.

First Data on Resistance to Pyrethroids in Wild Populations of Aedes albopictus from Spain.

The invasive mosquito, Aedes albopictus, found in Spain since 2004, is a competent vector of yellow fever, Zika, dengue, and chikungunya viruses among other diseases. Although controversial, the use of adulticiding is a relevant tool for vector control and could be crucial for the management of any possible outbreak of imported diseases. We present the 1st study in Spain on the susceptibility of field populations from Barcelona, Peñíscola, Castellón, and Mallorca of Ae. albopictus to several pyrethroids using either bioassays under the World Health Organization methodology and biochemical tests. In the bioassays, the discriminating concentrations were calculated using a local, susceptible laboratory strain. Different susceptibility levels were found for some combinations of populations and products. The biochemical tests carried out by enzymatic analysis supported these results, showing an overexpression of glutathione S-transferase activity in 1 population.

Structural and compositional changes in erythrocyte membrane of obese compared to normal-weight adolescents.

Unhealthy dietary habits are key determinants of obesity in adolescents. Assuming that dietary fat profile influences membrane lipid composition, the aim of this study was to analyze structural changes in the erythrocyte membrane of obese compared to normal-weight adolescents. The study was conducted in a group of 11 obese and 11 normal-weight adolescent subjects. The lipid profile, lipid peroxidation and acetylcholinesterase enzyme (AChE) activity were analyzed by conventional methods. The structural properties of reconstituted erythrocyte membrane were characterized by X-ray diffraction. Erythrocyte membrane from obese adolescents had a lipid profile characterized by a higher cholesterol/phospholipid ratio, an increase in saturated fatty acid and a decrease in monounsaturated and n-6 polyunsaturated fatty acid concentrations. Differences in lipid content were associated with changes in the structural properties of reconstituted membranes and the oxidative damage of erythrocyte membrane. The lower oxidative level shown in the obese group (0.15 ± 0.04 vs. 0.20 ± 0.06 nmol/mg for conjugated diene concentrations and 2.43 ± 0.25 vs. 2.83 ± 0.31 nmol/mg protein for malondialdehyde levels) was related to a lower unsaturation index. These changes in membrane structural properties were accompanied by a lower AChE activity (1.64 ± 0.13 vs. 1.91 ± 0.24 nmol AChE/[min mg protein]) in the obese group. The consequences of unhealthy dietary habits in adolescents are reflected in the membrane structural properties and may influence membrane-associated protein activities and functions.