The Biomimetic System of Oleanolic Acid and Oleic Acid at the Air-Water Interface-Interactions in Terms of Nanotechnology-Based Drug Delivery Systems.

Oleanolic acid (OLA) and oleic acid (OA) are ubiquitous in the plant kingdom, exhibiting a therapeutic effect on human health, and are components of novel pharmaceutical formulations. Since OLA has limited solubility, the utilization of nanotechnology-based drug delivery systems enhancing bioavailability is highly advantageous. We report on the interfacial behavior of the OLA:OA system at various molar ratios, using the Langmuir technique to assess the dependence of the molar composition on miscibility and rheological properties affecting film stability. Specifically, we evaluate the interfacial properties (morphology, thermodynamics, miscibility, and viscoelasticity) of the OLA:OA binary system in various molar ratios, and indicate how the OLA:OA system exhibits the most favorable molecular interactions. We apply the Langmuir monolayer technique along with the complementary techniques of Brewster angle microscopy, dilatational interfacial rheology, and excess free energy calculations. Results demonstrate that the properties of mixed monolayers depend on OLA:OA molar ratio. Most of the systems (OLA:OA 2:1, 1:1, 1:5) are assumed to be immiscible at surface pressures >10 mN/m. Moreover, the OLA:OA 1:2 is immiscible over the entire surface pressure range. However, the existence of miscibility between molecules of OLA and OA in the 5:1 for every surface pressure tested suggests that OA molecules incorporate into the OLA lattice structure, improving the stability of the mixed film. The results are discussed in terms of providing physicochemical insights into the behavior of the OLA:OA systems at the interface, which is of high interest in pharmaceutical design.

Mindfulness-based cognitive therapy reduces clinical symptoms, but do not change frontal alpha asymmetry in people with major depression disorder.

OBJECTIVES: Mindfulness-based cognitive therapy (MBCT) has demonstrated to be successful in the reduction of relapse rates in patients with recurrent major depressive disorder (MDD). Little is known if MBCT is effective for treating individuals with current MDD episode and about underlying psychophysiological mechanisms of symptoms reduction. The aim of the present study was to assess effects of MBCT on depressed individuals in terms of reduction of depressive and anxiety symptoms and to evaluate if this therapeutic improvement would be reflected on neurophysiological level by shift in frontal alpha asymmetry (FAA). PARTICIPANTS: We studied 20 individuals with current MDD. DESIGN: Participants were randomly assigned either to waiting list or 8-week MBCT. Before and after the treatment we have assessed depression, anxiety, and FAA in resting-state electroencephalogram (EEG) - an indicator of approach vs. withdrawal-related response dispositions and a vulnerability factor of MDD. RESULTS: In line with previous findings, reduction of depressive and anxiety symptoms, but no change in mean values of FAA in MBCT group was found. CONCLUSIONS: These results provide a support for the beneficial effects of MBCT in current MDD treatment, however, they do not support the hypothesis on alpha asymmetry change as a neural correlate of MDD improvement.