Piper regnellii extract biopolymer-based microparticles: production, characterization and antifungal activity.

AIMS: This study aims to improve characteristics of Piper regnellii extract to make it applicable in formulations to treat dermatophytosis, also known as ringworm. METHODS AND RESULTS: Microparticles (MPs) were produced by spray drying with gelatin, alginate and chitosan as encapsulating agents; characterized by scanning electron microscopy, encapsulation efficiency, thermal analyses and X-ray diffraction; and tested against Trichophyton rubrum by broth microdilution. Produced MPs had a mean diameter less than 2 µm, an increase in stability and release of the extract and good results for encapsulation efficiency, being 85·6% to gelatin MP, 71·3% to chitosan MP and 60·6% to alginate. MPs preserved the antifungal activity of P. regnellii extract T. rubrum. CONCLUSION: Microencapsulation provided a significant improvement in the stability of the P. regnellii extract and better solubilization of chemical compounds, maintaining the antifungal effect against T. rubrum. SIGNIFICANCE AND IMPACT OF THE STUDY: These results are useful for developing a formulation to treat fungal infections caused by dermatophyte species.

Characterization of fresh and aged natural ingredients used in historical ointments by molecular spectroscopic techniques: IR, Raman and fluorescence.

Natural organic materials used to prepare pharmaceutical mixtures including ointments and balsams have been characterized by a combined non-destructive spectroscopic analytical approach. Three classes of materials which include vegetable oils (olive, almond and palm tree), gums (Arabic and Tragacanth) and beeswax are considered in this study according to their widespread use reported in ancient recipes. Micro-FTIR, micro-Raman and fluorescence spectroscopies have been applied to fresh and mildly thermally aged samples. Vibrational characterization of these organic compounds is reported together with tabulated frequencies, highlighting all spectral features and changes in spectra which occur following artificial aging. Synchronous fluorescence spectroscopy has been shown to be particularly useful for the assessment of changes in oils after aging; spectral difference between Tragacanth and Arabic gum could be due to variations in origin and processing of raw materials. Analysis of these materials using non-destructive spectroscopic techniques provided important analytical information which could be used to guide further study.

Double blind clinical trial in a series of 115 patients with seborrheic dermatitis: prevention of relapses using a topical modulator of Toll like receptor 2.

AIM: Seborrheic dermatitis is a chronic inflammatory disease aggravated by Malassezia species. Toll-like receptors (TLR) are part of innate immune system that can be activated by yeasts. Previous studies showed that an association of Umbelliferae extract with a lipid (TLR2-Regul™) decreases the IL-8 expression in human skin in contact with M. furfur. The aim of this study was to assess the activity of a topical formulated with TLR2-Regul™ in the prevention of seborrheic dermatitis (SD) relapses. METHODS: Immune-competent SD adult patients were treated for SD (topical imidazoles or steroids). Cleared patients were randomized and received a topical containing TLR2-Regul™ (A) or its vehicle (B). Erythema, scales and pruritus were assessed during two months. RESULTS: The study included 115 patients, mean age 43.4, sex ratio m/f 1.5. At week 4 the relapse rate was 26% (N.=15) in group A and 43% (N.=25) in group B. At W8 the relapse rate was 21% (N.=12) in group A and 40% (N.=23) (P=0.0309). CONCLUSION: In this series of 115 adults with seborrheic dermatitis, patients treated with a topical containing TLR-Regul™ showed a significantly less relapse rate compared with the excipient group (P<0.05). TLR modulation could represent a new therapeutic approach in the prevention of seborrheic dermatitis relapses.

Potassium depletion and salt sensitivity in essential hypertension.

To evaluate the actual role of potassium depletion on blood pressure, 11 hypertensive patients were placed on a 10-day isocaloric diet providing a daily potassium intake of either 18 or 80 mmol, with each subject serving as his or her own control; the intake of sodium (220 mmol/day) and other minerals was kept constant. On day 11 each patient was also subjected to central volume expansion by water immersion associated with either normal or low potassium intake. After a 10-day period of low potassium intake, systolic blood pressure increased (P < 0.02) by 5 mm Hg, whereas serum potassium decreased (P < 0.001) by 0.9 mmol/L; no significant changes in urinary sodium and a marked increase in urinary calcium excretion (P < 0.001) were found during the 10-day low potassium intake. PRA (P < 0.02) and plasma aldosterone (P < 0.04) concentrations also decreased during low potassium intake in hypertensive patients. Even though an identical natriuretic response was found during the water immersion experiments with either high or low potassium in the whole hypertensive group, the evaluation of hypertensive subjects in relation to salt sensitivity enabled us to disclose pronounced differences in the natriuretic and calciuretic response. In fact, although an impaired natriuretic ability and moderate calcium loss were particularly found during water immersion in those hypertensive subjects exhibiting a lower salt sensitivity index, a predominant calcium depletion appeared to be the most important consequence of potassium depletion in the hypertensive subjects with a higher salt sensitivity index. By confirming that potassium depletion may exacerbate essential hypertension, our data also suggest that not only sodium restriction, but also potassium and calcium supplementation, could be particularly advisable in salt-sensitive hypertensive patients.

Electron transport-mediated wasteful consumption of NADH promotes the lethal response of U937 cells to tert-butylhydroperoxide.

The toxicity of a short-term exposure to tert-butylhydroperoxide in U937 cells was markedly reduced by chemically or experimentally induced respiratory deficiency. Rotenone mitigated the lethal effects of the hydroperoxide over the same concentration-range in which the complex I inhibitor inhibited oxygen utilization. U937 cells that were made respiration deficient by growing them in the presence of either chloramphenicol or ethidium bromide, were in both circumstances highly resistant to tert-butylhydroperoxide. The improved survival was not a direct consequence of the absence of electron transport, but rather was attributable to the large amounts of NADH which accumulate in the mitochondria of chemically hypoxic or respiration-deficient cells. Indeed, the toxicity elicited by tert-butylhydroperoxide was also abolished by supplementation with either of two different NADH-linked substrates, namely pyruvate or beta-hydroxybutyrate. Accumulation of intramitochondrial NADH, and the resulting cytoprotective effects, was associated with prevention of the loss of nonprotein sulphydryls and mitochondrial membrane potential. Neither rotenone nor pyruvate reduced the toxicity of tert-butylhydroperoxide in thiol-depleted cells. Taken together, these results indicate that depletion of mitochondrial NADH is a critical event in the cytotoxic response to tert-butylhydroperoxide since this pyridine nucleotide prevents mitochondrial dysfunction and cell death caused by the hydroperoxide. As a consequence, in hydroperoxide-treated cells electron transport is highly detrimental since it consumes mitochondrial NADH.