Evaluation of the enzymatic activity and stability of commercial bromelain incorporated in topical formulations.

BACKGROUND: Bromelain is a mixture of proteolytic enzymes found in various tissues of the pineapple plant (Ananas comosus) and other species of Bromeliaceae. Owing to its proteolytic activity, bromelain has been used in the food, medical, pharmaceutical and cosmetic industries, for its cell renewal, anti-ageing, whitening and anti-cellulite properties. OBJECTIVE: This study evaluated the stability of bromelain (commercial powder) incorporated in topical formulations. METHODS: Bromelain was incorporated at three concentrations, 0.5%, 1.0% and 2.0%, in oil-in-water emulsion and gel, and stored for six months at varying stress conditions. Stability was accessed by measuring the changes in the protein content, enzymatic activity, viscosity, rheology, pH and colour of the selected formulations. RESULTS: The colour of all the samples changed after 180 days of incubation, indicating the concentration-dependence and temperature-sensitive nature of these formulations. No relationship was observed between the changes in the pH, temperature and luminosity exposure in all the samples. Gels proved to be the least preferred base for incorporation of bromelain for use as a topical formulation, owing to its inability to maintain the integrity of bromelain, thereby affecting the formulation characteristics. CONCLUSION: The emulsion-based formulations at all the concentrations of bromelain were more stable than the gel-based formulation over 180 days of evaluation, at a temperature of 5°C, protected from light.

The pattern of glutamate-induced nitric oxide dynamics in vivo and its correlation with nNOS expression in rat hippocampus, cerebral cortex and striatum.

Nitric oxide (NO) is a diffusible intercellular messenger, acting via volume signaling in the brain and, therefore, the knowledge of its temporal dynamics is determinant to the understanding of its neurobiological role. However, such an analysis in vivo is challenging and indirect or static approaches are mostly used to infer NO bioactivity. In the present work we measured the glutamate-dependent NO temporal dynamics in vivo in the hippocampus (CA1, CA3 and DG subregions), cerebral cortex and striatum, using NO selective microelectrodes. Concurrently, the immunolocalization of nNOS was evaluated in each region. A transitory increase in NO levels occurred at higher amplitudes in the striatum and hippocampus relatively to the cortex. In the hippocampus, subtle differences in the profiles of NO signals were observed along the trisynaptic loop, with CA1 exhibiting the largest signals. The topography of NO temporal dynamics did not fully overlap with the pattern of the density of nNOS expression, suggesting that, complementary to the distribution of nNOS, the local regulation of NO synthesis as well as the decay pathways critically determine the effective NO concentration sensed by a target within the diffusional spread of this free radical. In sum, the rate and pattern of NO changes here shown, by incorporating regulatory mechanisms and processes that affect NO synthesis and decay, provide refined information critical for the understanding of NO multiple actions in the brain.

Schinus terebinthifolius Raddi extract and linoleic acid from Passiflora edulis synergistically decrease melanin synthesis in B16 cells and reconstituted epidermis.

Several treatments for skin whitening are available today, but few of them are completely adequate, especially owing to the carcinogenic potential attributed to classical drugs like hydroquinone, arbutin and kojic acid. To provide an alternative and safer technology for whitening, we developed two botanical compounds originated from Brazilian biodiversity, an extract of Schinus terebinthifolius Raddi and a linoleic acid fraction isolated from Passiflora edulis oil. The whitening effect of these compounds was assessed using biochemical assays and in vitro models including cellular assays and equivalent skin. The results showed that S. terebinthifolius Raddi extract is able to reduce the tyrosinase activity in vitro, and the combination of this extract with linoleic acid is able to decrease the level of melanin produced by B16 cells cultured with melanocyte-stimulating hormone. Furthermore, melanin was also reduced in human reconstituted epidermis (containing melanocytes) treated with the compounds. The combination of the compounds may provide a synergistic positive whitening effect rather than their isolated use. Finally, we demonstrated that the performance of these mixed compounds is comparable to classical molecules used for skin whitening, as kojic acid. This new natural mixture could be considered an alternative therapeutic agent for treating hyperpigmentation and an effective component in whitening cosmetics.

Kinetics and dynamic evaluation of specific immunotherapy.

UNLABELLED: Specific immunotherapy (SIT) is frequently used in the treatment of allergic diseases. However, the mechanisms by which SIT achieves clinical improvement remained unclear. We decided to study the in vivo kinetics of this therapy, using a nuclear medicine approach (leukocytes labelled with 99mTc-HMPAO) in patients on maintenance doses of specific immunotherapy with confirmed clinical efficacy. MATERIAL AND METHODS: We studied 13 allergic patients grouped according to different treatment schedules: subcutaneous aqueous allergenic extract (3 latex and 2 hymenoptera venom), subcutaneous depot extract (2 house dust mite and 2 pollens), subcutaneous modified allergens (2 pollens), sublingual extract (2 house dust mites). The control group included two allergic patients submitted to subcutaneous injections of bacterial extract (1 patient--positive control), and aqueous solution (1 patient). At the same time that the therapeutic allergen was administered subcutaneously, the autologous labelled white cells were injected intravenously in a peripheral vein in the contralateral arm. A thoracic dynamic acquisition of 60 mins, 64x64 matrix, 2 frame/min, in anterior view was performed. Static acquisition for 256x256 matrix, during 5 mins each at 60, 90, 120, 180, 240, 300 and 360 mins after the administration of the radiolabelled leukocytes, in thoracic (anterior and posterior), and abdominal view were performed. During the examination, the local erythema was monitored. A similar procedure was undertaken for Sublingual administration of immunotherapy. RESULTS: The inflammatory activity at the site of SIT injection (aqueous depot extract) started in the first hour and the increase was time related. For modified allergen extract and sublingual SIT the activity was present since the beginning of the administration. The ascendant lymphatic drainage, which was directed to the homolateral axillary region, to the lymphoid tissue of the upper mediastinum and to the anterior region of the neck began earlier. Thoracic focalisations were present for all the patients, whereas bowel focalisations were only observed for the subcutaneous route of administration. Sublingual SIT did not induce axillary or intestinal inflammatory focalisations, even though the patients had swallowed the allergenic extract. The uptake coefficient in individualized areas corrected to the uptake coefficient background was also studied. CONCLUSIONS: For the subcutaneous route of administration, except for glutaraldehyde-modified allergen, the local inflammatory activity at the allergenic injection site was significantly higher in depth and was time dependent, maintaining activity even after complete disappearance of the erythema and/or wheal. These results express a prompt inflammatory involvement of the immune system with this allergenic therapy, which was unexpected until now. We also observed differences concerning allergic diseases, the type of allergenic extracts and routes of administration.